git.iko.soy/squeal
on dev help sign in
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.circleci/config.yml+3−2
since splitsnapshots
unifiedsplit
@@ -2,9 +2,10 @@ version: 2
2jobs:
2jobs:
3 build:
3 build:
4 docker:
4 docker:
5− - image: haskell:8.2.2
5+ - image: haskell:8.6.5
6 - image: circleci/postgres:latest
6 - image: circleci/postgres:latest
7 environment:
7 environment:
8+ POSTGRES_USER: root
8 POSTGRES_DB: exampledb
9 POSTGRES_DB: exampledb
9 steps:
10 steps:
10 - checkout
11 - checkout
@@ -13,7 +14,7 @@ jobs:
13 - dependency-cache
14 - dependency-cache
14 - run: apt-get update && apt-get install -y libpq-dev xz-utils make
15 - run: apt-get update && apt-get install -y libpq-dev xz-utils make
15 - run: stack upgrade && stack update
16 - run: stack upgrade && stack update
16− - run: stack build
17+ - run: stack build --fast
17 - run: stack test
18 - run: stack test
18 - run: stack haddock
19 - run: stack haddock
19 - save_cache:
20 - save_cache:
README.md+83−87
@@ -45,7 +45,12 @@ composable and cover a large portion of SQL.
45* connection pools
45* connection pools
46* transactions
46* transactions
47* views
47* views
48−* composite and enumerated types
48+* array, composite and enumerated types
49+* json functions and operations
50+* multischema support
51+* correlated subqueries
52+* window functions
53+* text search
49
54
50## installation
55## installation
51
56
@@ -53,10 +58,16 @@ composable and cover a large portion of SQL.
53
58
54## testing
59## testing
55
60
56−start postgres on localhost port `5432` and create a database named `exampledb`.
61+Start postgres on localhost port `5432` and create a database named `exampledb`.
57
62
58`stack test`
63`stack test`
59
64
65+## contributing
66+
67+We welcome contributors.
68+Please make pull requests on the `dev` branch instead of `master`.
69+The `Issues` page is a good place to communicate.
70+
60## usage
71## usage
61
72
62Let's see an example!
73Let's see an example!
@@ -65,19 +76,17 @@ First, we need some language extensions because Squeal uses modern GHC
65features.
76features.
66
77
67```Haskell
78```Haskell
68−>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels
79+>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels -XFlexibleContexts
69−>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators
80+>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators -XGADTs
70```
81```
71
82
72We'll need some imports.
83We'll need some imports.
73
84
74```Haskell
85```Haskell
75−>>> import Control.Monad (void)
86+>>> import Control.Monad.IO.Class (liftIO)
76−>>> import Control.Monad.Base (liftBase)
77>>> import Data.Int (Int32)
87>>> import Data.Int (Int32)
78>>> import Data.Text (Text)
88>>> import Data.Text (Text)
79>>> import Squeal.PostgreSQL
89>>> import Squeal.PostgreSQL
80−>>> import Squeal.PostgreSQL.Render
81```
90```
82
91
83We'll use generics to easily convert between Haskell and PostgreSQL values.
92We'll use generics to easily convert between Haskell and PostgreSQL values.
@@ -92,27 +101,27 @@ we use `DataKinds` and `TypeOperators`.
92
101
93```Haskell
102```Haskell
94>>> :{
103>>> :{
104+type UsersColumns =
105+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
106+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext ]
107+type UsersConstraints = '[ "pk_users" ::: 'PrimaryKey '["id"] ]
108+type EmailsColumns =
109+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
110+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
111+ , "email" ::: 'NoDef :=> 'Null 'PGtext ]
112+type EmailsConstraints =
113+ '[ "pk_emails" ::: 'PrimaryKey '["id"]
114+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"] ]
95type Schema =
115type Schema =
96− '[ "users" ::: 'Table (
116+ '[ "users" ::: 'Table (UsersConstraints :=> UsersColumns)
97− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
98− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
99− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
100− ])
101− , "emails" ::: 'Table (
117+ , "emails" ::: 'Table (EmailsConstraints :=> EmailsColumns) ]
102− '[ "pk_emails" ::: 'PrimaryKey '["id"]
118+type Schemas = Public Schema
103− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
104− ] :=>
105− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
106− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
107− , "email" ::: 'NoDef :=> 'Null 'PGtext
108− ])
109− ]
110:}
119:}
111```
120```
112
121
113Notice the use of type operators.
122Notice the use of type operators.
114
123
115−`:::` is used to pair an alias `GHC.TypeLits.Symbol` with a `SchemumType`,
124+`:::` is used to pair an alias `Symbol` with a `SchemumType`,
116a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's `::`
125a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's `::`
117operator.
126operator.
118
127
@@ -121,7 +130,7 @@ yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,
121yielding a `ColumnType`. It is intended to connote Haskell's `=>` operator
130yielding a `ColumnType`. It is intended to connote Haskell's `=>` operator
122
131
123Next, we'll write `Definition`s to set up and tear down the schema. In
132Next, we'll write `Definition`s to set up and tear down the schema. In
124−Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`
133+Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`
125has two type parameters, corresponding to the schema
134has two type parameters, corresponding to the schema
126before being run and the schema after. We can compose definitions using `>>>`.
135before being run and the schema after. We can compose definitions using `>>>`.
127Here and in the rest of our commands we make use of overloaded
136Here and in the rest of our commands we make use of overloaded
@@ -130,19 +139,19 @@ labels to refer to named tables and columns in our schema.
130```Haskell
139```Haskell
131>>> :{
140>>> :{
132let
141let
133− setup :: Definition '[] Schema
142+ setup :: Definition (Public '[]) Schemas
134− setup =
143+ setup =
135 createTable #users
144 createTable #users
136− ( serial `As` #id :*
145+ ( serial `as` #id :*
137− (text & notNullable) `As` #name :* Nil )
146+ (text & notNullable) `as` #name )
138− ( primaryKey #id `As` #pk_users :* Nil ) >>>
147+ ( primaryKey #id `as` #pk_users ) >>>
139 createTable #emails
148 createTable #emails
140− ( serial `As` #id :*
149+ ( serial `as` #id :*
141− (int & notNullable) `As` #user_id :*
150+ (int & notNullable) `as` #user_id :*
142− (text & nullable) `As` #email :* Nil )
151+ (text & nullable) `as` #email )
143− ( primaryKey #id `As` #pk_emails :*
152+ ( primaryKey #id `as` #pk_emails :*
144 foreignKey #user_id #users #id
153 foreignKey #user_id #users #id
145− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
154+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
146:}
155:}
147```
156```
148
157
@@ -162,7 +171,7 @@ primary and foreign keys, making them somewhat complex. Our `teardown`
162```Haskell
171```Haskell
163>>> :{
172>>> :{
164let
173let
165− teardown :: Definition Schema '[]
174+ teardown :: Definition Schemas (Public '[])
166 teardown = dropTable #emails >>> dropTable #users
175 teardown = dropTable #emails >>> dropTable #users
167:}
176:}
168
177
@@ -171,57 +180,57 @@ DROP TABLE "emails";
171DROP TABLE "users";
180DROP TABLE "users";
172```
181```
173
182
183+We'll need a Haskell type for `User`s. We give the type `SOP.Generic` and
184+`SOP.HasDatatypeInfo` instances so that we can encode and decode `User`s.
185+
186+```Haskell
187+>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, GHC.Generic)
188+>>> instance SOP.Generic User
189+>>> instance SOP.HasDatatypeInfo User
190+```
191+
174−Next, we'll write `Manipulation`s to insert data into our two tables.
192+Next, we'll write `Manipulation_`s to insert `User`s into our two tables.
175−A `Manipulation` like `insertRow`, `update` or `deleteFrom`
193+A `Manipulation_` like `insertInto`, `update` or `deleteFrom`
176−has three type parameters, the schema it refers to, a list of parameters
194+has three type parameters, the schemas it refers to, input parameters
177−it can take as input, and a list of columns it produces as output. When
195+and an output row. When
178we insert into the users table, we will need a parameter for the `name`
196we insert into the users table, we will need a parameter for the `name`
179field but not for the `id` field. Since it's serial, we can use a default
197field but not for the `id` field. Since it's serial, we can use a default
180value. However, since the emails table refers to the users table, we will
198value. However, since the emails table refers to the users table, we will
181need to retrieve the user id that the insert generates and insert it into
199need to retrieve the user id that the insert generates and insert it into
182−the emails table. Take a careful look at the type and definition of both
200+the emails table. We can do this in a single `Manipulation_` by using a
183−of our inserts.
201+`with` statement.
184
202
185```Haskell
203```Haskell
186>>> :{
204>>> :{
187let
205let
188− insertUser :: Manipulation Schema '[ 'NotNull 'PGtext ] '[ "fromOnly" ::: 'NotNull 'PGint4 ]
206+ insertUser :: Manipulation_ Schemas User ()
189− insertUser = insertRow #users
207+ insertUser = with (u `as` #u) e
208+ where
209+ u = insertInto #users
190− (Default `As` #id :* Set (param @1) `As` #name :* Nil)
210+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))
191− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))
211+ OnConflictDoRaise (Returning_ (#id :* param @2 `as` #email))
192−:}
212+ e = insertInto_ #emails $ Select
193−
213+ (Default `as` #id :* Set (#u ! #id) `as` #user_id :* Set (#u ! #email) `as` #email)
194−>>> :{
214+ (from (common #u))
195−let
196− insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]
197− insertEmail = insertRow #emails
198− ( Default `As` #id :*
199− Set (param @1) `As` #user_id :*
200− Set (param @2) `As` #email :* Nil )
201− OnConflictDoNothing (Returning Nil)
202:}
215:}
203
216
204>>> printSQL insertUser
217>>> printSQL insertUser
205−INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING RETURNING "id" AS "fromOnly"
218+WITH "u" AS (INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) RETURNING "id" AS "id", ($2 :: text) AS "email") INSERT INTO "emails" ("user_id", "email") SELECT "u"."id", "u"."email" FROM "u" AS "u"
206−>>> printSQL insertEmail
207−INSERT INTO "emails" ("id", "user_id", "email") VALUES (DEFAULT, ($1 :: int4), ($2 :: text)) ON CONFLICT DO NOTHING
208```
219```
209
220
210−Next we write a `Query` to retrieve users from the database. We're not
221+Next we write a `Query_` to retrieve users from the database. We're not
211interested in the ids here, just the usernames and email addresses. We
222interested in the ids here, just the usernames and email addresses. We
212−need to use an inner join to get the right result. A `Query` is like a
223+need to use an `innerJoin` to get the right result. A `Query_` is like a
213−`Manipulation` with the same kind of type parameters.
224+`Manipulation_` with the same kind of type parameters.
214
225
215```Haskell
226```Haskell
216>>> :{
227>>> :{
217let
228let
218− getUsers :: Query Schema '[]
229+ getUsers :: Query_ Schemas () User
219− '[ "userName" ::: 'NotNull 'PGtext
220− , "userEmail" ::: 'Null 'PGtext ]
221− getUsers = select
230+ getUsers = select_
222− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* Nil)
231+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail)
223− ( from (table (#users `As` #u)
232+ ( from (table (#users `as` #u)
224− & innerJoin (table (#emails `As` #e))
233+ & innerJoin (table (#emails `as` #e))
225 (#u ! #id .== #e ! #user_id)) )
234 (#u ! #id .== #e ! #user_id)) )
226:}
235:}
227
236
@@ -229,25 +238,13 @@ let
229SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")
238SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")
230```
239```
231
240
232−Now that we've defined the SQL side of things, we'll need a Haskell type
233−for users. We give the type `Generics.SOP.Generic` and
234−`Generics.SOP.HasDatatypeInfo` instances so that we can decode the rows
235−we receive when we run `getUsers`. Notice that the record fields of the
236−`User` type match the column names of `getUsers`.
237−
238−```Haskell
239−>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, GHC.Generic)
240−>>> instance SOP.Generic User
241−>>> instance SOP.HasDatatypeInfo User
242−```
243−
244−Let's also create some users to add to the database.
241+Let's create some users to add to the database.
245
242
246```Haskell
243```Haskell
247>>> :{
244>>> :{
248let
245let
249 users :: [User]
246 users :: [User]
250− users =
247+ users =
251 [ User "Alice" (Just "alice@gmail.com")
248 [ User "Alice" (Just "alice@gmail.com")
252 , User "Bob" Nothing
249 , User "Bob" Nothing
253 , User "Carole" (Just "carole@hotmail.com")
250 , User "Carole" (Just "carole@hotmail.com")
@@ -266,19 +263,18 @@ transformer and when the schema doesn't change we can use `Monad` and
266```Haskell
263```Haskell
267>>> :{
264>>> :{
268let
265let
269− session :: PQ Schema Schema IO ()
266+ session :: PQ Schemas Schemas IO ()
270 session = do
267 session = do
271− idResults <- traversePrepared insertUser (Only . userName <$> users)
272− ids <- traverse (fmap fromOnly . getRow 0) idResults
273− traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))
268+ _ <- traversePrepared_ insertUser users
274 usersResult <- runQuery getUsers
269 usersResult <- runQuery getUsers
275 usersRows <- getRows usersResult
270 usersRows <- getRows usersResult
276− liftBase $ print (usersRows :: [User])
271+ liftIO $ print (usersRows :: [User])
277in
272in
278− void . withConnection "host=localhost port=5432 dbname=exampledb" $
273+ withConnection "host=localhost port=5432 dbname=exampledb" $
279 define setup
274 define setup
280 & pqThen session
275 & pqThen session
281 & pqThen (define teardown)
276 & pqThen (define teardown)
282:}
277:}
283[User {userName = "Alice", userEmail = Just "alice@gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just "carole@hotmail.com"}]
278[User {userName = "Alice", userEmail = Just "alice@gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just "carole@hotmail.com"}]
279+-}
284```
280```
RELEASE NOTES.md+837
@@ -1,5 +1,842 @@
1## RELEASE NOTES
1## RELEASE NOTES
2
2
3+### Version 0.5
4+
5+Version 0.5 makes a number of large changes and additions to Squeal.
6+I want to thank folks who contributed issues and pull requests;
7+Raveline, rimmington, ilyakooo0, chshersh, reygoch, and more.
8+
9+**Multi-schema support**
10+
11+Previous versions of Squeal only supported definitions in the "public"
12+schema. Squeal 0.5 adds support for multiple schemas with the new kind
13+
14+```Haskell
15+type SchemasType = [(Symbol,SchemaType)]
16+```
17+
18+In order to upgrade your queries, manipulations and definitions from
19+Squeal 0.4, you will have to apply the `Public` type family, which indicates
20+that your only schema is the "public" schema.
21+
22+```Haskell
23+-- Squeal 0.4
24+setup :: Definition '[] Schema
25+
26+-- Squeal 0.5
27+setup :: Definition (Public '[]) (Public Schema)
28+```
29+
30+You can create non-public schemas using `createSchema` and inversely
31+remove them using `dropSchema`. There is also an idempotent
32+`createSchemaIfNotExists`.
33+
34+In order to handle aliases which may refer to non-public schemas, Squeal 0.5
35+introduces `QualifiedAlias`es. A `QualifiedAlias` can be referred to using
36+the `(!)` operator from the `IsQualified` typeclass; but if you want to refer
37+to an alias from the "public" schema, you can continue to use a single
38+overloaded label, no need to write `#public ! #tab`, just write `#tab`.
39+
40+**Top-level statements**
41+
42+As a consequence of multi-schema support, common table expressions that
43+a `Query` or `Manipulation` may refer to had to be broken into a new parameter.
44+Additionally, `Query` gained another new parameter for its outer scope which
45+will be discussed in the next section.
46+
47+To simplify type signatures that you have to write for top-level queries
48+and manipulations, Squeal 0.5 introduces the `Query_` and `Manipulation_`
49+type families.
50+
51+```
52+type family Query_
53+ (schemas :: SchemasType)
54+ (parameters :: Type)
55+ (row :: Type) where
56+ Query_ schemas params row =
57+ Query '[] '[] schemas (TuplePG params) (RowPG row)
58+```
59+
60+As you see, a top-level `Query_` has no outer scope and no common
61+table expressions in scope, they are empty `'[]`. Moreover,
62+its parameters and row parameters are now `Type`s, which are
63+converted to corresponding Postgres types using the `TuplePG`
64+and `RowPG` type families. This means you can write the type signatures
65+for your top-level statements using the Haskell types that you
66+intend to input and retrieve when running the statements. Similar
67+to `Query_`, there is a `Manipulation_` type, the only difference
68+being that a general `Manipulation` doesn't have an outer scope,
69+only a scope for common table expressions.
70+
71+**Subquery expressions**
72+
73+Previous versions of Squeal offered subquery expression support
74+but there were issues. The common use case of using the `IN` operator
75+from SQL was overly complex. There was a proliferation of subquery
76+functions to handle different comparison operators, each with two versions
77+for comparing `ALL` or `ANY` of the query rows. And, most confoundedly,
78+there was no way to support the `EXISTS` subquery because the "outer scope"
79+for a query was not available.
80+
81+Squeal adds an outer scope to the `Query` type.
82+
83+```Haskell
84+newtype Query
85+ (outer :: FromType)
86+ (commons :: FromType)
87+ (schemas :: SchemasType)
88+ (params :: [NullityType])
89+ (row :: RowType)
90+ = UnsafeQuery { renderQuery :: ByteString }
91+```
92+
93+This enables a well-typed `exists` function.
94+
95+```Haskell
96+exists
97+ :: Query (Join outer from) commons schemas params row
98+ -> Condition outer commons grp schemas params from
99+```
100+
101+The `in_` and `notIn` functions were simplified to handle the most
102+common use case of comparing to a list of values.
103+
104+```Haskell
105+in_
106+ :: Expression outer commons grp schemas params from ty -- ^ expression
107+ -> [Expression outer commons grp schemas params from ty]
108+ -> Condition outer commons grp schemas params from
109+```
110+
111+Finally, general subquery comparisons were abstracted to work with
112+any comparison operators, using the `Operator` type which will be discussed in
113+the next section.
114+
115+```Haskell
116+subAll
117+ :: Expression outer commons grp schemas params from ty1
118+ -> Operator ty1 ty2 ('Null 'PGbool)
119+ -> Query (Join outer from) commons schemas params '[col ::: ty2]
120+ -> Condition outer commons grp schemas params from
121+
122+subAny
123+ :: Expression outer commons grp schemas params from ty1
124+ -> Operator ty1 ty2 ('Null 'PGbool)
125+ -> Query (Join outer from) commons schemas params '[col ::: ty2]
126+ -> Condition outer commons grp schemas params from
127+```
128+
129+**Expression RankNTypes**
130+
131+Squeal 0.5 introduces RankNType type synonyms for common expression patterns.
132+The simplest example is the `Expr` type, a type for "closed" expressions
133+that cannot reference any aliases or parameters.
134+
135+```Haskell
136+type Expr x
137+ = forall outer commons grp schemas params from
138+ . Expression outer commons grp schemas params from x
139+```
140+
141+There is also a function type `(-->)`, which is a subtype of the usual Haskell function
142+type `(->)`.
143+
144+```Haskell
145+type (-->) x y
146+ = forall outer commons grp schemas params from
147+ . Expression outer commons grp schemas params from x
148+ -> Expression outer commons grp schemas params from y
149+```
150+
151+We saw in the subquery section that there is an `Operator` type.
152+
153+```Haskell
154+type Operator x1 x2 y
155+ = forall outer commons grp schemas params from
156+ . Expression outer commons grp schemas params from x1
157+ -> Expression outer commons grp schemas params from x2
158+ -> Expression outer commons grp schemas params from y
159+```
160+
161+There are also types `FunctionN` and `FunctionVar` for n-ary functions
162+and variadic functions.
163+
164+```
165+type FunctionN xs y
166+ = forall outer commons grp schemas params from
167+ . NP (Expression outer commons grp schemas params from) xs
168+ -> Expression outer commons grp schemas params from y
169+```
170+
171+An n-ary function takes an `NP` list of `Expression`s as its argument.
172+Squeal 0.5 adds a helpful operator `(*:)`, to help scrap your `Nil`s.
173+You can construct an `NP` list now by using the operator `(:*)`,
174+until your last element, using `(*:)` there. For instance, the function
175+`atan2_` takes two arguments, `atan2_ (pi *: 2)`.
176+
177+**Selections**
178+
179+Previously, Squeal provided a couple versions of `SELECT` depending
180+on whether you wanted to select all columns of a unique table
181+in the from clause, i.e. `*`, all columns of a particular table
182+in the from clause, i.e. `.*`, or a list of columns from the from clause.
183+
184+Squeal 0.5 refactors this pattern into a `Selection` GADT type, allowing
185+for abstraction and combinations that were not possible before.
186+
187+```Haskell
188+data Selection outer commons grp schemas params from row where
189+ Star
190+ :: HasUnique tab from row
191+ => Selection outer commons 'Ungrouped schemas params from row
192+ DotStar
193+ :: Has tab from row
194+ => Alias tab
195+ -> Selection outer commons 'Ungrouped schemas params from row
196+ List
197+ :: SListI row
198+ => NP (Aliased (Expression outer commons grp schemas params from)) row
199+ -> Selection outer commons grp schemas params from row
200+ Over
201+ :: SListI row
202+ => NP (Aliased (WindowFunction outer commons grp schemas params from)) row
203+ -> WindowDefinition outer commons grp schemas params from
204+ -> Selection outer commons grp schemas params from row
205+ Also
206+ :: Selection outer commons grp schemas params from right
207+ -> Selection outer commons grp schemas params from left
208+ -> Selection outer commons grp schemas params from (Join left right)
209+```
210+
211+In addition to the `Star`, `DotStar` and `List` constructors, there is an
212+`Also` constructor combinator, which enables users to combine `Selection`s.
213+Additionally, there is an `Over` constructor that is used to enable
214+window functions, described in the next section.
215+
216+To upgrade from Squeal 0.4, you will replace `selectStar` with `select Star`,
217+replace `selectDotStar #tab` with `select (DotStar #tab)`. The `List`
218+selection is such a common use case that there is a function `select_` which
219+automatically applies it, so to upgrade from Squeal 0.4, replace `select`
220+with `select_`. There are also independent `selectDistinct` and `selectDistinct_`
221+functions to filter out duplicate rows.
222+
223+**Query clauses**
224+
225+Previously, Squeal provided a couple versions of `INSERT` depending
226+on whether you wanted to insert `VALUES` or a query.
227+
228+Squeal 0.5 refactors this pattern into a `QueryClause` GADT.
229+
230+```
231+-- Squeal 0.4
232+insertRow_ #tab (Set 2 `as` #col1 :* Default `as` #col2)
233+insertQuery_ #tab (selectStar (from (table #other_tab)))
234+
235+-- Squeal 0.5
236+insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))
237+insertInto_ #tab (Subquery (select Star (from (table #other_tab))))
238+```
239+
240+**Window functions and aggregation**
241+
242+Previous versions of Squeal provided no support for window functions.
243+Squeal 0.5 adds support for window functions. We saw `Over` in the
244+previous section.
245+
246+```Haskell
247+Over
248+ :: SListI row
249+ => NP (Aliased (WindowFunction outer commons grp schemas params from)) row
250+ -> WindowDefinition outer commons grp schemas params from
251+ -> Selection outer commons grp schemas params from row
252+```
253+
254+`Over` combines window functions with window definitions. A `WindowDefinition`
255+is constructed using the `partitionBy` function, optionally with an `orderBy`
256+clause. For example,
257+
258+```Haskell
259+query :: Query_ (Public Schema) () (Row Int32 Int32)
260+query = select
261+ (#col1 & Also (rank `as` #col2 `Over` (partitionBy #col1 & orderBy [#col2 & Asc])))
262+ (from (table #tab))
263+```
264+
265+Here the `rank` function is a `WindowFunction`
266+
267+```Haskell
268+rank :: WinFun0 ('NotNull 'PGint8)
269+rank = UnsafeWindowFunction "rank()"
270+```
271+
272+`WinFun0` is a RankNType, like `Expr` was, used for no argument window functions.
273+Similarly, there are also `WinFun1` and `WinFunN` types for
274+window functions and n-ary window functions.
275+
276+In order to use the same syntax for certain window functions and aggregate functions,
277+a new typeclass `Aggregate` was introduced. So for instance, `sum_` can be
278+either a `Distinction` `Expression` or a `WindowFunction`, used either with
279+a `groupBy` or with a `partitionBy` in the appropriate way.
280+
281+```
282+data Distinction (expr :: kind -> Type) (ty :: kind)
283+ = All (expr ty)
284+ | Distinct (expr ty)
285+```
286+
287+Aggregate functions can be run over all rows or only over distinct rows,
288+while window functions bear no such distinction.
289+
290+**Migrations**
291+
292+Thanks to [https://github.com/Raveline](Raveline) Squeal 0.5 introduces
293+a function `defaultMain` to easily create a command line program to
294+run or rewind your migrations.
295+
296+Previously, Squeal's migrations were impure, allowing in addition to
297+running `Definition`s to run arbitrary `IO` operations, such as inserting
298+data into the database or printing out status messages. In order to
299+provide compatibility with other migration systems, Squeal 0.5 introduces
300+pure migrations, that is migrations that are only `Definition`s.
301+
302+```Haskell
303+data Migration p schemas0 schemas1 = Migration
304+ { name :: Text -- ^ The `name` of a `Migration`.
305+ -- Each `name` in a `Migration` should be unique.
306+ , up :: p schemas0 schemas1 -- ^ The `up` instruction of a `Migration`.
307+ , down :: p schemas1 schemas0 -- ^ The `down` instruction of a `Migration`.
308+ } deriving (GHC.Generic)
309+```
310+
311+A pure migration is a `Migration Definition`, a pair of inverse
312+`Definition`s with a unique name. To recover impure migrations, Squeal 0.5
313+introduces the `Terminally` type.
314+
315+```Haskell
316+newtype Terminally trans monad x0 x1 = Terminally
317+ { runTerminally :: trans x0 x1 monad () }
318+```
319+
320+`Terminally` applies the indexed monad transformer and the monad it transforms
321+to the unit type `()`, thereby turning an indexed monad into a `Category`. An
322+impure migration is a `Migration (Terminally PQ IO)`. You can always cast
323+a pure migration into an impure migration with the functor, `pureMigration`.
324+
325+```Haskell
326+pureMigration
327+ :: Migration Definition schemas0 schemas1
328+ -> Migration (Terminally PQ IO) schemas0 schemas1
329+```
330+
331+To run either pure or impure migrations, Squeal 0.5 introduces
332+a typeclass, `Migratory`.
333+
334+```
335+class Category p => Migratory p where
336+
337+ migrateUp
338+ :: AlignedList (Migration p) schemas0 schemas1
339+ -> PQ schemas0 schemas1 IO ()
340+
341+ migrateDown
342+ :: AlignedList (Migration p) schemas0 schemas1
343+ -> PQ schemas1 schemas0 IO ()
344+```
345+
346+The signatures of `migrateUp` and `migrateDown` have been changed
347+to make them easier to compose with other `PQ` actions.
348+
349+**Transactions**
350+
351+You can now run transactions `ephemerally`, guaranteed to roll back,
352+but return the result or throw the exception that the transaction
353+would have generated. This is useful for testing. You can also
354+`transactionallyRetry` computations, retrying the transaction if
355+a [serialization failure](https://www.postgresql.org/docs/11/transaction-iso.html#XACT-REPEATABLE-READ) occurs.
356+
357+**Types**
358+
359+Squeal now supports money via a `Money` Haskell `Type` and a `'PGmoney`
360+`PGType`. Squeal 0.5 also adds support for creating domain types
361+with `createDomain`.
362+
363+**Time**
364+
365+Squeal 0.5 adds support for new functions; `now`, `makeDate`, `makeTime`,
366+, `makeTimestamp`, and `makeTimestamptz`, a function `interval_` for
367+constructing time intervals out multiples of `TimeUnit`s, and a new
368+`TimeOp` class, defining affine space operators for time types and their
369+differences.
370+
371+**Literals**
372+
373+Squeal allows you to include Haskell values in your statements using
374+out of line `parameter`s, but often you want to include them inline,
375+as a SQL `literal`. Squeal 0.5 enables this using the `Literal` class.
376+
377+**Set returning functions**
378+
379+Squeal 0.5 adds support for set returning functions such as `unnest`,
380+with the `RankNType` `SetOfFunction`, which can be used as as a `FromClause`.
381+
382+**Text search**
383+
384+Squeal 0.5 adds extensive support for text search types, functions and operators.
385+
386+**Much more**
387+
388+Lots more changes went into and under the hood of the new version.
389+The `Expression` module was split into coherent submodules since it
390+had grown to immense proportions. New modules `Alias`, `PG` and `List`
391+were added to relieve some of the burden that the `Schema` module
392+had been carrying. Rendering has been better unified with a new
393+`RenderSQL` typeclass. Type level list concatenation with the `Additional`
394+typeclass has been added. `Manipulation`s `update` and `delete`
395+were upgraded, so you can leave out fields you don't want to update and
396+use `USING` clauses in deletes. Upserts which were previously broken
397+now work. The `IO` typeclass hierarchy was changed from `MonadBase`
398+and `MonadBaseControl` to `MonadIO` and `MonadUnliftIO`. A new
399+`withRecursive` `Manipulation` was added. `SquealException`s were
400+refactored and a `trySqueal` function added. Arrays were refactored.
401+And there was probably more I've forgotten.
402+
403+### Version 0.4
404+
405+Version 0.4 strengthens Squeal's type system, adds
406+support for multidimensional arrays, improves support
407+for container type, improves `with` statements,
408+improves runtime exceptions, accomodates SQL's three-valued logic,
409+adds subquery expressions, and adds table and view type expressions.
410+
411+**Types**
412+
413+Squeal 0.4 renames some kinds to aid intuition:
414+
415+```Haskell
416+type RowType = [(Symbol, NullityType)] -- previously RelationType
417+type FromType = [(Symbol, RowType)] -- previously RelationsType
418+```
419+
420+Null safety for array and composite types is gained by having the base
421+type of an array be a `NullityType` and the base type of a composite
422+a `RowType`.
423+
424+```Haskell
425+data PGType
426+ = ..
427+ | PGvararray NullityType
428+ | PGfixarray Nat NullityType
429+ | PGcomposite RowType
430+```
431+
432+Squeal embeds Postgres types into Haskell using data kinds and type-in-type:
433+
434+```Haskell
435+data PGType = PGbool | ..
436+data NullityType = Null PGType | NotNull PGType
437+type RowType = [(Symbol, NullityType)] -- previously RelationType
438+type FromType = [(Symbol, RowType)] -- previously RelationsType
439+```
440+
441+In another sense, we can embed Haskell types
442+into Postgres types by providing type families:
443+
444+```Haskell
445+type family PG (hask :: Type) :: PGType
446+type family NullPG (hask :: Type) :: NullityType
447+type family TuplePG (hask :: Type) :: [NullityType]
448+type family RowPG (hask :: Type) :: RowType
449+```
450+
451+Let's look at these one by one.
452+
453+`PG` was introduced in Squeal 0.3. It was a closed type family that
454+associates some Haskell types to their obvious corresponding Postgres
455+types like `PG Double = 'PGfloat8`. It only worked on base types,
456+no arrays or composites. Squeal 0.4 extends it to
457+such container types and makes it an open type family so that
458+users can make their own type instances.
459+
460+`NullPG` had a different name before but it does the obvious
461+thing for Haskell with `Maybe`s:
462+
463+```Haskell
464+type family NullPG hask where
465+ NullPG (Maybe hask) = 'Null (PG hask)
466+ NullPG hask = 'NotNull (PG hask)
467+```
468+
469+`TuplePG` uses generics to turn tuple types (including records)
470+into lists of `NullityType`s in the logical way, e.g.
471+`TuplePG (Bool, Day) = '[ 'PGbool, 'PGdate]`.
472+
473+`RowPG` also uses generics to turn record types into a `RowType` in the logical way, e.g.
474+
475+```Haskell
476+>>> data Person = Person { name :: Text, age :: Int32 } deriving GHC.Generic
477+>>> instance SOP.Generic Person
478+>>> instance SOP.HasDatatypeInfo Person
479+>>> :kind! TuplePG Person
480+TuplePG Person :: [NullityType]
481+= '['NotNull 'PGtext, 'NotNull 'PGint4]
482+>>> :kind! RowPG Person
483+RowPG Person :: [(Symbol, NullityType)]
484+= '["name" ::: 'NotNull 'PGtext, "age" ::: 'NotNull 'PGint4]
485+```
486+
487+We've already seen a hint of why these types are useful in one construction
488+from Squeal 0.3. Creating composite types in Postgres directly from a Haskell
489+record type essentially uses `RowPG`. Another important use is in simplifying
490+the type signatures for a `Query` or `Manipulation`. Very often, you will have
491+a tuple type corresponding to the parameters and a record type corresponding
492+to the returned columns of a `Query` or `Manipulation`. Instead of writing
493+boilerplate signature you can reuse these with the help of `TuplePG` and `RowPG`
494+
495+For instance:
496+
497+```Haskell
498+>>> :{
499+let
500+ query :: Query '["user" ::: 'View (RowPG Person)] (TuplePG (Only Int32)) (RowPG Person)
501+ query = selectStar (from (view #user) & where_ (#age .> param @1))
502+:}
503+```
504+
505+**Arrays**
506+
507+In addition to being able to encode and decode basic Haskell types
508+like `Int16` and `Text`, Squeal 0.4 permits you to encode and decode Haskell types to
509+Postgres array types. The `Vector` type corresponds to to variable length arrays.
510+And thanks to an idea from [Mike Ledger](https://github.com/mikeplus64),
511+homogeneous tuples correspond to fixed length arrays. We can even
512+create multi-dimensional fixed length arrays. Let's see an example.
513+
514+```Haskell
515+>>> :{
516+data Row = Row
517+ { col1 :: Vector Int16
518+ , col2 :: (Maybe Int16,Maybe Int16)
519+ , col3 :: ((Int16,Int16),(Int16,Int16),(Int16,Int16))
520+ } deriving (Eq, GHC.Generic)
521+:}
522+
523+>>> instance Generic Row
524+>>> instance HasDatatypeInfo Row
525+```
526+
527+Define a simple round trip query.
528+
529+```Haskell
530+>>> :{
531+let
532+ roundTrip :: Query '[] (TuplePG Row) (RowPG Row)
533+ roundTrip = values_ $
534+ parameter @1 (int2 & vararray) `as` #col1 :*
535+ parameter @2 (int2 & fixarray @2) `as` #col2 :*
536+ parameter @3 (int2 & fixarray @2 & fixarray @3) `as` #col3
537+:}
538+
539+>>> :set -XOverloadedLists
540+>>> let input = Row [1,2] (Just 1,Nothing) ((1,2),(3,4),(5,6))
541+>>> :{
542+void . withConnection "host=localhost port=5432 dbname=exampledb" $ do
543+ result <- runQueryParams roundTrip input
544+ Just output <- firstRow result
545+ liftBase . print $ input == output
546+:}
547+True
548+```
549+
550+**Containers**
551+
552+Squeal aims to provide a correspondence between Haskell types and Postgres types.
553+In particular, Haskell ADTs with nullary constructors can correspond to
554+Postgres enum types and Haskell record types can correspond to Postgres
555+composite types. However, it's not always obvious that that's how a user
556+will choose to store values of those types. So Squeal 0.4 introduces newtypes
557+whose purpose is to specify how a user wants to store values of a type.
558+
559+```Haskell
560+newtype Json hask = Json {getJson :: hask}
561+newtype Jsonb hask = Jsonb {getJsonb :: hask}
562+newtype Composite record = Composite {getComposite :: record}
563+newtype Enumerated enum = Enumerated {getEnumerated :: enum}
564+```
565+
566+Let's see an example:
567+
568+```Haskell
569+>>> data Schwarma = Beef | Lamb | Chicken deriving (Eq, Show, GHC.Generic)
570+>>> instance SOP.Generic Schwarma
571+>>> instance SOP.HasDatatypeInfo Schwarma
572+>>>
573+>>> data Person = Person {name :: Text, age :: Int32} deriving (Eq, Show, GHC.Generic)
574+>>> instance SOP.Generic Person
575+>>> instance SOP.HasDatatypeInfo Person
576+>>> instance Aeson.FromJSON Person
577+>>> instance Aeson.ToJSON Person
578+```
579+
580+We can create the equivalent Postgres types directly from their Haskell types.
581+
582+```Haskell
583+>>> :{
584+type Schema =
585+ '[ "schwarma" ::: 'Typedef (PG (Enumerated Schwarma))
586+ , "person" ::: 'Typedef (PG (Composite Person))
587+ ]
588+:}
589+
590+>>> :{
591+let
592+ setup :: Definition '[] Schema
593+ setup =
594+ createTypeEnumFrom @Schwarma #schwarma >>>
595+ createTypeCompositeFrom @Person #person
596+:}
597+```
598+
599+Let's demonstrate how to associate our Haskell types `Schwarma` and `Person`
600+with enumerated, composite or json types in Postgres. First create a Haskell
601+`Row` type using the `Enumerated`, `Composite` and `Json` newtypes as fields.
602+
603+```Haskell
604+>>> :{
605+data Row = Row
606+ { schwarma :: Enumerated Schwarma
607+ , person1 :: Composite Person
608+ , person2 :: Json Person
609+ } deriving (Eq, GHC.Generic)
610+:}
611+
612+>>> instance Generic Row
613+>>> instance HasDatatypeInfo Row
614+>>> :{
615+let
616+ input = Row
617+ (Enumerated Chicken)
618+ (Composite (Person "Faisal" 24))
619+ (Json (Person "Ahmad" 48))
620+:}
621+```
622+
623+Once again, define a round trip query.
624+
625+```Haskell
626+>>> :{
627+let
628+ roundTrip :: Query Schema (TuplePG Row) (RowPG Row)
629+ roundTrip = values_ $
630+ parameter @1 (typedef #schwarma) `as` #schwarma :*
631+ parameter @2 (typedef #person) `as` #person1 :*
632+ parameter @3 json `as` #person2
633+:}
634+```
635+
636+Finally, we can drop our type definitions.
637+
638+```Haskell
639+>>> :{
640+let
641+ teardown :: Definition Schema '[]
642+ teardown = dropType #schwarma >>> dropType #person
643+:}
644+```
645+
646+Now let's run it.
647+
648+```Haskell
649+>>> :{
650+let
651+ session = do
652+ result <- runQueryParams roundTrip input
653+ Just output <- firstRow result
654+ liftBase . print $ input == output
655+in
656+ void . withConnection "host=localhost port=5432 dbname=exampledb" $
657+ define setup
658+ & pqThen session
659+ & pqThen (define teardown)
660+:}
661+True
662+```
663+
664+**With**
665+
666+Squeal 0.3 supported WITH statements but there's a couple problems with them.
667+Here's the type signature for `with` in Squeal 0.3.
668+
669+```Haskell
670+with
671+ :: SOP.SListI commons
672+ => NP (Aliased (Manipulation schema params)) (common ': commons)
673+ -- ^ common table expressions
674+ -> Manipulation (With (common ': commons) schema) params results
675+ -> Manipulation schema params results
676+```
677+
678+The first problem is that `with` only works with `Manipulations`.
679+It can work on `Query`s by using `queryStatement` but it still will
680+return a `Manipulation`. We can fix this issue by making `with` a
681+method of a type class with instances for both `Query` and `Manipulation`.
682+
683+The second problem is that all the common table expressions
684+refer the base schema, whereas in SQL, each subsequent CTE can
685+refer to previous CTEs as well. But this can be fixed! First define a datatype:
686+
687+```Haskell
688+data CommonTableExpression statement params schema0 schema1 where
689+ CommonTableExpression
690+ :: Aliased (statement schema params) (alias ::: cte)
691+ -> CommonTableExpression statement params schema (alias ::: 'View cte ': schema)
692+```
693+
694+It's just a wrapper around an aliased statement, where the statement
695+could be either a `Query` or `Manipulation`, but it augments the schema
696+by adding a view to it. It almost looks like a morphism between schemas
697+but there is no way yet to compose them. Luckily, Squeal already has
698+a datatype for this, which is used for migrations, the `AlignedList`
699+type which is really the "free category". So we can then define a `With` type class:
700+
701+```Haskell
702+class With statement where
703+ with
704+ :: AlignedList (CommonTableExpression statement params) schema0 schema1
705+ -> statement schema1 params row
706+ -> statement schema0 params row
707+```
708+
709+By giving `Aliasable` instances to CTEs and aligned singleton lists of CTEs (i.e. scrap-your-nils), we get a nice syntax for WITH statements in Squeal.
710+
711+Here's an example of using `with` for a `Query` and a `Manipulation`:
712+
713+```Haskell
714+>>> :{
715+let
716+ query :: Query
717+ '[ "t1" ::: 'View
718+ '[ "c1" ::: 'NotNull 'PGtext
719+ , "c2" ::: 'NotNull 'PGtext] ]
720+ '[]
721+ '[ "c1" ::: 'NotNull 'PGtext
722+ , "c2" ::: 'NotNull 'PGtext ]
723+ query = with (
724+ selectStar (from (view #t1)) `as` #t2 :>>
725+ selectStar (from (view #t2)) `as` #t3
726+ ) (selectStar (from (view #t3)))
727+in printSQL query
728+:}
729+WITH "t2" AS (SELECT * FROM "t1" AS "t1"), "t3" AS (SELECT * FROM "t2" AS "t2") SELECT * FROM "t3" AS "t3"
730+
731+>>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]
732+
733+>>> :{
734+let
735+ manipulation :: Manipulation
736+ '[ "products" ::: 'Table ProductsTable
737+ , "products_deleted" ::: 'Table ProductsTable
738+ ] '[ 'NotNull 'PGdate] '[]
739+ manipulation = with
740+ (deleteFrom #products (#date .< param @1) ReturningStar `as` #deleted_rows)
741+ (insertQuery_ #products_deleted (selectStar (from (view (#deleted_rows `as` #t)))))
742+in printSQL manipulation
743+:}
744+WITH "deleted_rows" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "deleted_rows" AS "t"
745+```
746+
747+**Three Valued Logic**
748+
749+In previous versions of Squeal, conditions followed classical two valued logic
750+of `true` and `false`.
751+
752+```Haskell
753+-- Squeal 0.3
754+type Condition schema from grouping params =
755+ Expression schema from grouping params ('NotNull 'PGbool)
756+```
757+
758+I had thought that three valued logic, which is what SQL uses, was confusing.
759+However, multiple users reported being confused at being forced to do `NULL`
760+handling, particularly in their left joins. Since the original motivation
761+of being less confusing evaporated I decided to switch to three valued logic
762+of `true`, `false` and `null_`.
763+
764+```Haskell
765+-- Squeal 0.4
766+type Condition schema from grouping params =
767+ Expression schema from grouping params ('Null 'PGbool)
768+```
769+
770+**Subquery Expressions**
771+
772+Squeal 0.4 adds support for subquery expressions such as `IN` and `op ANY/ALL`.
773+
774+**Row Types**
775+
776+Squeal 0.4 adds functions to define type expressions from tables and views
777+and a type expression for user defined types, `typetable`, `typeview` and
778+`typedef`.
779+
780+**Runtime Exceptions**
781+
782+Squeal now has an exception type which gives details on the sort of error
783+encountered and handler functions.
784+
785+```Haskell
786+data SquealException
787+ = PQException
788+ { sqlExecStatus :: LibPQ.ExecStatus
789+ , sqlStateCode :: Maybe ByteString
790+ -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html
791+ , sqlErrorMessage :: Maybe ByteString
792+ }
793+ | ResultException Text
794+ | ParseException Text
795+ deriving (Eq, Show)
796+instance Exception SquealException
797+
798+catchSqueal
799+ :: MonadBaseControl IO io
800+ => io a
801+ -> (SquealException -> io a) -- ^ handler
802+ -> io a
803+
804+handleSqueal
805+ :: MonadBaseControl IO io
806+ => (SquealException -> io a) -- ^ handler
807+ -> io a -> io a
808+```
809+
810+**Additional Changes**
811+
812+Squeal 0.4 adds `field` and `index` functions to get components of composite
813+and array expressions.
814+
815+Squeal 0.4 adds a dependency on `records-sop` to offload a lot of boilerplate
816+type family logic that was needed for `RowPG`.
817+
818+The above changes required major and minor changes to Squeal DSL functions.
819+Please consult the documentation.
820+
821+### Version 0.3.2 - August 4, 2018
822+
823+Version 0.3.2 features extensive support for `JSON` functionality with
824+more than 50 new functions.
825+This work is entirely due to [Mike Ledger](https://github.com/mikeplus64)
826+who has been making terrific contributions to Squeal. Thanks!
827+We also got some examples in the documentation for pools submitted by
828+[Raveline](https://github.com/Raveline). I'm so pleased to be
829+getting pull requests and issue submissions from you all!
830+
831+### Version 0.3.1 - July 7, 2018
832+
833+Version 0.3.1 of Squeal enables the "Scrap your Nils" trick for
834+heterogeneous lists of `Alias`es, `Aliased` expressions, `PGlabel`s and `By`s
835+with the typeclasses `IsLabel`, `IsQualified`, `IsPGlabel`,
836+and the new `Aliasable` typeclass, to eliminate all need of using `Nil` in a list.
837+There were a couple minor name changes, i.e. the function `group` was renamed to `groupBy`.
838+Please consult the documentation.
839+
3### Version 0.3 - June 26, 2018
840### Version 0.3 - June 26, 2018
4
841
5Version 0.3 of Squeal adds views as well as composite and enumerated types to Squeal.
842Version 0.3 of Squeal adds views as well as composite and enumerated types to Squeal.
scrap-your-nils.mdnew file+60
@@ -0,0 +1,60 @@
1+## Scrap your Nils
2+
3+One of the most useful types I've come across in Haskell is the type of
4+"heterogeneous lists". This is the same as the [Rec](http://hackage.haskell.org/package/vinyl-0.8.1.1/docs/Data-Vinyl-Core.html)
5+datatype from the [vinyl](http://hackage.haskell.org/package/vinyl) library.
6+It's also the same as the [NP](http://hackage.haskell.org/package/generics-sop-0.3.2.0/docs/Generics-SOP-NP.html)
7+datatype from the [generics-sop](http://hackage.haskell.org/package/generics-sop) library.
8+Squeal makes heavy use of this type.
9+
10+```Haskell
11+>>> import Generics.SOP (NP(..))
12+>>> :i NP
13+type role NP representational nominal
14+data NP (a :: k -> *) (b :: [k]) where
15+ Nil :: forall k (a :: k -> *). NP a '[]
16+ (:*) :: forall k (a :: k -> *) (x :: k) (xs :: [k]).
17+ (a x) -> (NP a xs) -> NP a (x : xs)
18+ -- Defined in ‘Generics.SOP.NP’
19+```
20+
21+This type allows us to construct "product" types, where the types of the individual
22+"terms" are hosted at the type level.
23+
24+```Haskell
25+>>> :set -XDataKinds
26+>>> import Generics.SOP (I(..))
27+>>> let example = I "foo" :* I pi :* Nil :: NP I '[String, Double]
28+>>> example
29+I "foo" :* I 3.141592653589793 :* Nil
30+```
31+
32+One thing Squeal uses `NP` for is to form lists of aliases,
33+using GHC's `OverloadedLabels` extension, hosting the names
34+of the aliases themselves at the type level.
35+
36+```Haskell
37+>>> :set -XKindSignatures -XOverloadedLabels -XFlexibleInstances -XMultiParamTypeClasses
38+>>> import GHC.TypeLits
39+>>> import GHC.OverloadedLabels
40+>>> data Alias (alias :: Symbol) = Alias deriving (Eq,Ord,Show)
41+>>> instance IsLabel label (Alias label) where fromLabel = Alias
42+>>> let aliases = #foo :* #bar :* Nil :: NP Alias '["foo", "bar"]
43+```
44+
45+However, it's very ugly to have to end every list with `:* Nil`.
46+When I announced the release of Squeal, people rightly [complained](https://www.reddit.com/r/haskell/comments/6yr5v6/announcing_squeal_a_deep_embedding_of_sql_in/dmq8vvn)
47+about the syntactic noise. Luckily, there's a neat trick we can use to get rid of it.
48+Making an `IsLabel` instance not only for elements of our list
49+but also for lists of length 1, we can ask GHC to interpret
50+the last label as a list.
51+
52+```Haskell
53+>>> instance IsLabel label (NP Alias '[label]) where fromLabel = Alias :* Nil
54+>>> let aliases' = #foo :* #bar :: NP Alias '["foo", "bar"]
55+```
56+
57+Version 0.3.1 of Squeal enables the "Scrap your Nils" trick for
58+heterogeneous lists of `Alias`es, `Aliased` expressions, `PGlabel`s and `By`s
59+with the typeclasses `IsLabel`, `IsQualified`, `IsPGlabel`,
60+and the new `Aliasable` typeclass, to eliminate all need of using `Nil` in a list.
squeal-postgresql/exe/Example.hs+46−49
@@ -11,8 +11,7 @@
11
11
12module Main (main, main2) where
12module Main (main, main2) where
13
13
14−import Control.Monad (void)
14+import Control.Monad.IO.Class (MonadIO (..))
15−import Control.Monad.Base (liftBase, MonadBase)
16import Data.Int (Int16, Int32)
15import Data.Int (Int16, Int32)
17import Data.Monoid ((<>))
16import Data.Monoid ((<>))
18import Data.Text (Text)
17import Data.Text (Text)
@@ -29,7 +28,7 @@ type Schema =
29 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
28 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
30 '[ "id" ::: 'Def :=> 'NotNull 'PGint4
29 '[ "id" ::: 'Def :=> 'NotNull 'PGint4
31 , "name" ::: 'NoDef :=> 'NotNull 'PGtext
30 , "name" ::: 'NoDef :=> 'NotNull 'PGtext
32− , "vec" ::: 'NoDef :=> 'NotNull ('PGvararray 'PGint2)
31+ , "vec" ::: 'NoDef :=> 'NotNull ('PGvararray ('Null 'PGint2))
33 ])
32 ])
34 , "emails" ::: 'Table (
33 , "emails" ::: 'Table (
35 '[ "pk_emails" ::: 'PrimaryKey '["id"]
34 '[ "pk_emails" ::: 'PrimaryKey '["id"]
@@ -39,72 +38,70 @@ type Schema =
39 , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
38 , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
40 , "email" ::: 'NoDef :=> 'Null 'PGtext
39 , "email" ::: 'NoDef :=> 'Null 'PGtext
41 ])
40 ])
41+ , "positive" ::: 'Typedef 'PGfloat4
42 ]
42 ]
43
43
44+type Schemas = Public Schema
45+
44−setup :: Definition '[] Schema
46+setup :: Definition (Public '[]) Schemas
45−setup =
47+setup =
46 createTable #users
48 createTable #users
47− ( serial `As` #id :*
49+ ( serial `as` #id :*
48− (text & notNullable) `As` #name :*
50+ (text & notNullable) `as` #name :*
49− (vararray int2 & notNullable) `As` #vec :* Nil )
51+ (vararray int2 & notNullable) `as` #vec )
50− ( primaryKey #id `As` #pk_users :* Nil )
52+ ( primaryKey #id `as` #pk_users )
51 >>>
53 >>>
52 createTable #emails
54 createTable #emails
53− ( serial `As` #id :*
55+ ( serial `as` #id :*
54− (int & notNullable) `As` #user_id :*
56+ hask @Int32 `as` #user_id :*
55− (text & nullable) `As` #email :* Nil )
57+ hask @(Maybe Text) `as` #email )
56− ( primaryKey #id `As` #pk_emails :*
58+ ( primaryKey #id `as` #pk_emails :*
57 foreignKey #user_id #users #id
59 foreignKey #user_id #users #id
58− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
60+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
59−
61+ >>>
62+ createDomain #positive real (#value .> 0 .&& (#value & isNotNull))
63+
60−teardown :: Definition Schema '[]
64+teardown :: Definition Schemas (Public '[])
61−teardown = dropTable #emails >>> dropTable #users
65+teardown = dropType #positive >>> dropTable #emails >>> dropTable #users
62−
66+
63−insertUser :: Manipulation Schema '[ 'NotNull 'PGtext, 'NotNull ('PGvararray 'PGint2)]
67+insertUser :: Manipulation_ Schemas (Text, VarArray (Vector (Maybe Int16))) (Only Int32)
64− '[ "fromOnly" ::: 'NotNull 'PGint4 ]
65−insertUser = insertRows #users
68+insertUser = insertInto #users
66− (Default `As` #id :* Set (param @1) `As` #name :* Set (param @2) `As` #vec :* Nil) []
69+ (Values_ (Default `as` #id :* Set (param @1) `as` #name :* Set (param @2) `as` #vec))
67− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))
70+ (OnConflict (OnConstraint #pk_users) DoNothing) (Returning_ (#id `as` #fromOnly))
68−
71+
69−insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]
72+insertEmail :: Manipulation_ Schemas (Int32, Maybe Text) ()
70−insertEmail = insertRows #emails
73+insertEmail = insertInto_ #emails
71− ( Default `As` #id :*
72− Set (param @1) `As` #user_id :*
74+ (Values_ (Default `as` #id :* Set (param @1) `as` #user_id :* Set (param @2) `as` #email))
73− Set (param @2) `As` #email :* Nil ) []
75+
74− OnConflictDoNothing (Returning Nil)
76+getUsers :: Query_ Schemas () User
75−
76−getUsers :: Query Schema '[]
77− '[ "userName" ::: 'NotNull 'PGtext
78− , "userEmail" ::: 'Null 'PGtext
79− , "userVec" ::: 'NotNull ('PGvararray 'PGint2)]
80−getUsers = select
77+getUsers = select_
81− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* #u ! #vec `As` #userVec :* Nil)
78+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail :* #u ! #vec `as` #userVec)
82− ( from (table (#users `As` #u)
79+ ( from (table (#users `as` #u)
83− & innerJoin (table (#emails `As` #e))
80+ & innerJoin (table (#emails `as` #e))
84 (#u ! #id .== #e ! #user_id)) )
81 (#u ! #id .== #e ! #user_id)) )
85
82
86−data User = User { userName :: Text, userEmail :: Maybe Text, userVec :: Vector (Maybe Int16) }
83+data User = User { userName :: Text, userEmail :: Maybe Text, userVec :: VarArray (Vector (Maybe Int16)) }
87 deriving (Show, GHC.Generic)
84 deriving (Show, GHC.Generic)
88instance SOP.Generic User
85instance SOP.Generic User
89instance SOP.HasDatatypeInfo User
86instance SOP.HasDatatypeInfo User
90
87
91users :: [User]
88users :: [User]
92−users =
89+users =
93− [ User "Alice" (Just "alice@gmail.com") [Nothing, Just 1]
90+ [ User "Alice" (Just "alice@gmail.com") (VarArray [Nothing, Just 1])
94− , User "Bob" Nothing [Just 2, Nothing]
91+ , User "Bob" Nothing (VarArray [Just 2, Nothing])
95− , User "Carole" (Just "carole@hotmail.com") [Just 3]
92+ , User "Carole" (Just "carole@hotmail.com") (VarArray [Just 3])
96 ]
93 ]
97
94
98−session :: (MonadBase IO pq, MonadPQ Schema pq) => pq ()
95+session :: (MonadIO pq, MonadPQ Schemas pq) => pq ()
99session = do
96session = do
100− liftBase $ Char8.putStrLn "manipulating"
97+ liftIO $ Char8.putStrLn "manipulating"
101 idResults <- traversePrepared insertUser ([(userName user, userVec user) | user <- users])
98 idResults <- traversePrepared insertUser ([(userName user, userVec user) | user <- users])
102 ids <- traverse (fmap fromOnly . getRow 0) idResults
99 ids <- traverse (fmap fromOnly . getRow 0) idResults
103 traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))
100 traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))
104− liftBase $ Char8.putStrLn "querying"
101+ liftIO $ Char8.putStrLn "querying"
105 usersResult <- runQuery getUsers
102 usersResult <- runQuery getUsers
106 usersRows <- getRows usersResult
103 usersRows <- getRows usersResult
107− liftBase $ print (usersRows :: [User])
104+ liftIO $ print (usersRows :: [User])
108
105
109main :: IO ()
106main :: IO ()
110main = do
107main = do
@@ -122,7 +119,7 @@ main = do
122
119
123main2 :: IO ()
120main2 :: IO ()
124main2 =
121main2 =
125− void . withConnection "host=localhost port=5432 dbname=exampledb" $
122+ withConnection "host=localhost port=5432 dbname=exampledb" $
126 define setup
123 define setup
127 & pqThen session
124 & pqThen session
128 & pqThen (define teardown)
125 & pqThen (define teardown)
squeal-postgresql/squeal-postgresql.cabal+71−10
@@ -1,5 +1,5 @@
1name: squeal-postgresql
1name: squeal-postgresql
2−version: 0.3.0.0
2+version: 0.5.1.0
3synopsis: Squeal PostgreSQL Library
3synopsis: Squeal PostgreSQL Library
4description: Squeal is a type-safe embedding of PostgreSQL in Haskell
4description: Squeal is a type-safe embedding of PostgreSQL in Haskell
5homepage: https://github.com/morphismtech/squeal
5homepage: https://github.com/morphismtech/squeal
@@ -22,12 +22,40 @@ library
22 hs-source-dirs: src
22 hs-source-dirs: src
23 exposed-modules:
23 exposed-modules:
24 Squeal.PostgreSQL
24 Squeal.PostgreSQL
25+ Squeal.PostgreSQL.Alias
25 Squeal.PostgreSQL.Binary
26 Squeal.PostgreSQL.Binary
26 Squeal.PostgreSQL.Definition
27 Squeal.PostgreSQL.Definition
28+ Squeal.PostgreSQL.Definition.Function
29+ Squeal.PostgreSQL.Definition.Index
30+ Squeal.PostgreSQL.Definition.Table
31+ Squeal.PostgreSQL.Definition.Table.Constraint
32+ Squeal.PostgreSQL.Definition.Type
33+ Squeal.PostgreSQL.Definition.Schema
34+ Squeal.PostgreSQL.Definition.View
27 Squeal.PostgreSQL.Expression
35 Squeal.PostgreSQL.Expression
36+ Squeal.PostgreSQL.Expression.Aggregate
37+ Squeal.PostgreSQL.Expression.Collection
38+ Squeal.PostgreSQL.Expression.Comparison
39+ Squeal.PostgreSQL.Expression.Json
40+ Squeal.PostgreSQL.Expression.Literal
41+ Squeal.PostgreSQL.Expression.Logic
42+ Squeal.PostgreSQL.Expression.Math
43+ Squeal.PostgreSQL.Expression.Null
44+ Squeal.PostgreSQL.Expression.Parameter
45+ Squeal.PostgreSQL.Expression.Range
46+ Squeal.PostgreSQL.Expression.Set
47+ Squeal.PostgreSQL.Expression.Sort
48+ Squeal.PostgreSQL.Expression.Subquery
49+ Squeal.PostgreSQL.Expression.Text
50+ Squeal.PostgreSQL.Expression.TextSearch
51+ Squeal.PostgreSQL.Expression.Time
52+ Squeal.PostgreSQL.Expression.Type
53+ Squeal.PostgreSQL.Expression.Window
54+ Squeal.PostgreSQL.List
28 Squeal.PostgreSQL.Manipulation
55 Squeal.PostgreSQL.Manipulation
29 Squeal.PostgreSQL.Migration
56 Squeal.PostgreSQL.Migration
30 Squeal.PostgreSQL.Pool
57 Squeal.PostgreSQL.Pool
58+ Squeal.PostgreSQL.PG
31 Squeal.PostgreSQL.PQ
59 Squeal.PostgreSQL.PQ
32 Squeal.PostgreSQL.Render
60 Squeal.PostgreSQL.Render
33 Squeal.PostgreSQL.Query
61 Squeal.PostgreSQL.Query
@@ -37,39 +65,73 @@ library
37 ghc-options: -Wall
65 ghc-options: -Wall
38 build-depends:
66 build-depends:
39 aeson >= 1.2.4.0
67 aeson >= 1.2.4.0
40− , base >= 4.10.1.0 && < 5.0
68+ , base >= 4.11.1.0 && < 5.0
41 , binary-parser >= 0.5.5
69 , binary-parser >= 0.5.5
42 , bytestring >= 0.10.8.2
70 , bytestring >= 0.10.8.2
43 , bytestring-strict-builder >= 0.4.5
71 , bytestring-strict-builder >= 0.4.5
44 , deepseq >= 1.4.3.0
72 , deepseq >= 1.4.3.0
73+ , free-categories >= 0.1.0.0
45− , generics-sop >= 0.3.2.0
74+ , generics-sop >= 0.3.2.0 && < 0.5.0.0
46− , lifted-base >= 0.2.3.12
47 , mmorph >= 1.1.1
75 , mmorph >= 1.1.1
48− , monad-control >= 1.0.2.3
49 , mtl >= 2.2.2
76 , mtl >= 2.2.2
50 , network-ip >= 0.3.0.2
77 , network-ip >= 0.3.0.2
51 , postgresql-binary >= 0.12.1
78 , postgresql-binary >= 0.12.1
52 , postgresql-libpq >= 0.9.4.1
79 , postgresql-libpq >= 0.9.4.1
80+ , records-sop >= 0.1.0.0
53 , resource-pool >= 0.2.3.2
81 , resource-pool >= 0.2.3.2
54 , scientific >= 0.3.5.3
82 , scientific >= 0.3.5.3
55 , text >= 1.2.3.0
83 , text >= 1.2.3.0
56 , time >= 1.8.0.2
84 , time >= 1.8.0.2
57 , transformers >= 0.5.2.0
85 , transformers >= 0.5.2.0
58− , transformers-base >= 0.4.4
86+ , unliftio >= 0.2.10
87+ , unliftio-pool >= 0.2.1.0
59 , uuid-types >= 1.0.3
88 , uuid-types >= 1.0.3
60 , vector >= 0.12.0.1
89 , vector >= 0.12.0.1
61
90
62−test-suite squeal-postgresql-doctest
91+test-suite doctest
63 default-language: Haskell2010
92 default-language: Haskell2010
64 type: exitcode-stdio-1.0
93 type: exitcode-stdio-1.0
65 hs-source-dirs: test
94 hs-source-dirs: test
66 ghc-options: -Wall
95 ghc-options: -Wall
67− main-is: DocTest.hs
96+ main-is: Doc.hs
68 build-depends:
97 build-depends:
69 base >= 4.10.0.0
98 base >= 4.10.0.0
70 , doctest >= 0.11.4
99 , doctest >= 0.11.4
100+ , squeal-postgresql
101+
102+test-suite properties
103+ default-language: Haskell2010
104+ type: exitcode-stdio-1.0
105+ hs-source-dirs: test
106+ ghc-options: -Wall
107+ main-is: Property.hs
108+ build-depends:
109+ base >= 4.10.0.0
110+ , bytestring >= 0.10.8.2
111+ , hedgehog >= 1.0
112+ , mtl >= 2.2.2
113+ , scientific >= 0.3.5.3
114+ , squeal-postgresql
115+ , time >= 1.8.0.2
116+
117+test-suite spec
118+ default-language: Haskell2010
119+ type: exitcode-stdio-1.0
120+ hs-source-dirs: test
121+ ghc-options: -Wall
122+ main-is: Spec.hs
123+ build-depends:
124+ base >= 4.10.0.0
125+ , async >= 2.2.2
126+ , bytestring >= 0.10.8.2
127+ , generics-sop >= 0.3.1.0
128+ , hspec >= 2.4.8
129+ , mtl >= 2.2.2
130+ , squeal-postgresql
131+ , text >= 1.2.2.2
132+ , vector >= 0.12.0.1
71
133
72−executable squeal-postgresql-example
134+executable example
73 default-language: Haskell2010
135 default-language: Haskell2010
74 hs-source-dirs: exe
136 hs-source-dirs: exe
75 ghc-options: -Wall
137 ghc-options: -Wall
@@ -82,5 +144,4 @@ executable squeal-postgresql-example
82 , squeal-postgresql
144 , squeal-postgresql
83 , text >= 1.2.2.2
145 , text >= 1.2.2.2
84 , transformers >= 0.5.2.0
146 , transformers >= 0.5.2.0
85− , transformers-base >= 0.4.4
86 , vector >= 0.12.0.1
147 , vector >= 0.12.0.1
squeal-postgresql/src/Squeal/PostgreSQL.hs+112−106
@@ -1,7 +1,7 @@
1{-|
1{-|
2Module: Squeal.PostgreSQL
2Module: Squeal.PostgreSQL
3−Description: Squeel export module
3+Description: Squeal export module
4−Copyright: (c) Eitan Chatav, 2017
4+Copyright: (c) Eitan Chatav, 2019
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
@@ -11,17 +11,15 @@ Let's see an example!
11First, we need some language extensions because Squeal uses modern GHC
11First, we need some language extensions because Squeal uses modern GHC
12features.
12features.
13
13
14−>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels
14+>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels -XFlexibleContexts
15−>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators
15+>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators -XGADTs
16−
16+
17We'll need some imports.
17We'll need some imports.
18
18
19−>>> import Control.Monad (void)
19+>>> import Control.Monad.IO.Class (liftIO)
20−>>> import Control.Monad.Base (liftBase)
21>>> import Data.Int (Int32)
20>>> import Data.Int (Int32)
22>>> import Data.Text (Text)
21>>> import Data.Text (Text)
23>>> import Squeal.PostgreSQL
22>>> import Squeal.PostgreSQL
24−>>> import Squeal.PostgreSQL.Render
25
23
26We'll use generics to easily convert between Haskell and PostgreSQL values.
24We'll use generics to easily convert between Haskell and PostgreSQL values.
27
25
@@ -32,26 +30,26 @@ The first step is to define the schema of our database. This is where
32we use @DataKinds@ and @TypeOperators@.
30we use @DataKinds@ and @TypeOperators@.
33
31
34>>> :{
32>>> :{
33+type UsersColumns =
34+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
35+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext ]
36+type UsersConstraints = '[ "pk_users" ::: 'PrimaryKey '["id"] ]
37+type EmailsColumns =
38+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
39+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
40+ , "email" ::: 'NoDef :=> 'Null 'PGtext ]
41+type EmailsConstraints =
42+ '[ "pk_emails" ::: 'PrimaryKey '["id"]
43+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"] ]
35type Schema =
44type Schema =
36− '[ "users" ::: 'Table (
45+ '[ "users" ::: 'Table (UsersConstraints :=> UsersColumns)
37− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
38− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
39− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
40− ])
41− , "emails" ::: 'Table (
46+ , "emails" ::: 'Table (EmailsConstraints :=> EmailsColumns) ]
42− '[ "pk_emails" ::: 'PrimaryKey '["id"]
47+type Schemas = Public Schema
43− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
44− ] :=>
45− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
46− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
47− , "email" ::: 'NoDef :=> 'Null 'PGtext
48− ])
49− ]
50:}
48:}
51
49
52Notice the use of type operators.
50Notice the use of type operators.
53
51
54−`:::` is used to pair an alias `GHC.TypeLits.Symbol` with a `SchemumType`,
52+`:::` is used to pair an alias `GHC.TypeLits.Symbol` with a `SchemasType`, a `SchemumType`,
55a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's @::@
53a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's @::@
56operator.
54operator.
57
55
@@ -60,7 +58,7 @@ yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,
60yielding a `ColumnType`. It is intended to connote Haskell's @=>@ operator
58yielding a `ColumnType`. It is intended to connote Haskell's @=>@ operator
61
59
62Next, we'll write `Definition`s to set up and tear down the schema. In
60Next, we'll write `Definition`s to set up and tear down the schema. In
63−Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`
61+Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`
64has two type parameters, corresponding to the schema
62has two type parameters, corresponding to the schema
65before being run and the schema after. We can compose definitions using `>>>`.
63before being run and the schema after. We can compose definitions using `>>>`.
66Here and in the rest of our commands we make use of overloaded
64Here and in the rest of our commands we make use of overloaded
@@ -68,19 +66,19 @@ labels to refer to named tables and columns in our schema.
68
66
69>>> :{
67>>> :{
70let
68let
71− setup :: Definition '[] Schema
69+ setup :: Definition (Public '[]) Schemas
72− setup =
70+ setup =
73 createTable #users
71 createTable #users
74− ( serial `As` #id :*
72+ ( serial `as` #id :*
75− (text & notNullable) `As` #name :* Nil )
73+ (text & notNullable) `as` #name )
76− ( primaryKey #id `As` #pk_users :* Nil ) >>>
74+ ( primaryKey #id `as` #pk_users ) >>>
77 createTable #emails
75 createTable #emails
78− ( serial `As` #id :*
76+ ( serial `as` #id :*
79− (int & notNullable) `As` #user_id :*
77+ (int & notNullable) `as` #user_id :*
80− (text & nullable) `As` #email :* Nil )
78+ (text & nullable) `as` #email )
81− ( primaryKey #id `As` #pk_emails :*
79+ ( primaryKey #id `as` #pk_emails :*
82 foreignKey #user_id #users #id
80 foreignKey #user_id #users #id
83− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
81+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
84:}
82:}
85
83
86We can easily see the generated SQL is unsurprising looking.
84We can easily see the generated SQL is unsurprising looking.
@@ -89,14 +87,14 @@ We can easily see the generated SQL is unsurprising looking.
89CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));
87CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));
90CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);
88CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);
91
89
92−Notice that @setup@ starts with an empty schema @'[]@ and produces @Schema@.
90+Notice that @setup@ starts with an empty public schema @(Public '[])@ and produces @Schemas@.
93In our `createTable` commands we included `TableConstraint`s to define
91In our `createTable` commands we included `TableConstraint`s to define
94primary and foreign keys, making them somewhat complex. Our @teardown@
92primary and foreign keys, making them somewhat complex. Our @teardown@
95`Definition` is simpler.
93`Definition` is simpler.
96
94
97>>> :{
95>>> :{
98let
96let
99− teardown :: Definition Schema '[]
97+ teardown :: Definition Schemas (Public '[])
100 teardown = dropTable #emails >>> dropTable #users
98 teardown = dropTable #emails >>> dropTable #users
101:}
99:}
102
100
@@ -104,76 +102,64 @@ let
104DROP TABLE "emails";
102DROP TABLE "emails";
105DROP TABLE "users";
103DROP TABLE "users";
106
104
105+We'll need a Haskell type for @User@s. We give the type `Generics.SOP.Generic` and
106+`Generics.SOP.HasDatatypeInfo` instances so that we can encode and decode @User@s.
107+
108+>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, GHC.Generic)
109+>>> instance SOP.Generic User
110+>>> instance SOP.HasDatatypeInfo User
111+
107−Next, we'll write `Manipulation`s to insert data into our two tables.
112+Next, we'll write `Manipulation_`s to insert @User@s into our two tables.
108−A `Manipulation` like `insertRow`, `update` or `deleteFrom`
113+A `Manipulation_` like `insertInto`, `update` or `deleteFrom`
109−has three type parameters, the schema it refers to, a list of parameters
114+has three type parameters, the schemas it refers to, input parameters
110−it can take as input, and a list of columns it produces as output. When
115+and an output row. When
111we insert into the users table, we will need a parameter for the @name@
116we insert into the users table, we will need a parameter for the @name@
112field but not for the @id@ field. Since it's serial, we can use a default
117field but not for the @id@ field. Since it's serial, we can use a default
113value. However, since the emails table refers to the users table, we will
118value. However, since the emails table refers to the users table, we will
114need to retrieve the user id that the insert generates and insert it into
119need to retrieve the user id that the insert generates and insert it into
115−the emails table. Take a careful look at the type and definition of both
120+the emails table. We can do this in a single `Manipulation_` by using a
116−of our inserts.
121+`with` statement.
117−
118−>>> :{
119−let
120− insertUser :: Manipulation Schema '[ 'NotNull 'PGtext ] '[ "fromOnly" ::: 'NotNull 'PGint4 ]
121− insertUser = insertRow #users
122− (Default `As` #id :* Set (param @1) `As` #name :* Nil)
123− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))
124−:}
125
122
126>>> :{
123>>> :{
127let
124let
128− insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]
125+ insertUser :: Manipulation_ Schemas User ()
129− insertEmail = insertRow #emails
126+ insertUser = with (u `as` #u) e
127+ where
128+ u = insertInto #users
130− ( Default `As` #id :*
129+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))
131− Set (param @1) `As` #user_id :*
130+ OnConflictDoRaise (Returning_ (#id :* param @2 `as` #email))
132− Set (param @2) `As` #email :* Nil )
131+ e = insertInto_ #emails $ Select
133− OnConflictDoNothing (Returning Nil)
132+ (Default `as` #id :* Set (#u ! #id) `as` #user_id :* Set (#u ! #email) `as` #email)
133+ (from (common #u))
134:}
134:}
135
135
136>>> printSQL insertUser
136>>> printSQL insertUser
137−INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING RETURNING "id" AS "fromOnly"
137+WITH "u" AS (INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) RETURNING "id" AS "id", ($2 :: text) AS "email") INSERT INTO "emails" ("user_id", "email") SELECT "u"."id", "u"."email" FROM "u" AS "u"
138−>>> printSQL insertEmail
139−INSERT INTO "emails" ("id", "user_id", "email") VALUES (DEFAULT, ($1 :: int4), ($2 :: text)) ON CONFLICT DO NOTHING
140
138
141−Next we write a `Query` to retrieve users from the database. We're not
139+Next we write a `Query_` to retrieve users from the database. We're not
142interested in the ids here, just the usernames and email addresses. We
140interested in the ids here, just the usernames and email addresses. We
143−need to use an inner join to get the right result. A `Query` is like a
141+need to use an `innerJoin` to get the right result. A `Query_` is like a
144−`Manipulation` with the same kind of type parameters.
142+`Manipulation_` with the same kind of type parameters.
145
143
146>>> :{
144>>> :{
147let
145let
148− getUsers :: Query Schema '[]
146+ getUsers :: Query_ Schemas () User
149− '[ "userName" ::: 'NotNull 'PGtext
150− , "userEmail" ::: 'Null 'PGtext ]
151− getUsers = select
147+ getUsers = select_
152− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* Nil)
148+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail)
153− ( from (table (#users `As` #u)
149+ ( from (table (#users `as` #u)
154− & innerJoin (table (#emails `As` #e))
150+ & innerJoin (table (#emails `as` #e))
155 (#u ! #id .== #e ! #user_id)) )
151 (#u ! #id .== #e ! #user_id)) )
156:}
152:}
157
153
158>>> printSQL getUsers
154>>> printSQL getUsers
159SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")
155SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")
160
156
161−Now that we've defined the SQL side of things, we'll need a Haskell type
162−for users. We give the type `Generics.SOP.Generic` and
163−`Generics.SOP.HasDatatypeInfo` instances so that we can decode the rows
164−we receive when we run @getUsers@. Notice that the record fields of the
165−@User@ type match the column names of @getUsers@.
166−
167−>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, GHC.Generic)
168−>>> instance SOP.Generic User
169−>>> instance SOP.HasDatatypeInfo User
170−
171−Let's also create some users to add to the database.
157+Let's create some users to add to the database.
172
158
173>>> :{
159>>> :{
174let
160let
175 users :: [User]
161 users :: [User]
176− users =
162+ users =
177 [ User "Alice" (Just "alice@gmail.com")
163 [ User "Alice" (Just "alice@gmail.com")
178 , User "Bob" Nothing
164 , User "Bob" Nothing
179 , User "Carole" (Just "carole@hotmail.com")
165 , User "Carole" (Just "carole@hotmail.com")
@@ -190,38 +176,58 @@ transformer and when the schema doesn't change we can use `Monad` and
190
176
191>>> :{
177>>> :{
192let
178let
193− session :: PQ Schema Schema IO ()
179+ session :: PQ Schemas Schemas IO ()
194 session = do
180 session = do
195− idResults <- traversePrepared insertUser (Only . userName <$> users)
196− ids <- traverse (fmap fromOnly . getRow 0) idResults
197− traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))
181+ _ <- traversePrepared_ insertUser users
198 usersResult <- runQuery getUsers
182 usersResult <- runQuery getUsers
199 usersRows <- getRows usersResult
183 usersRows <- getRows usersResult
200− liftBase $ print (usersRows :: [User])
184+ liftIO $ print (usersRows :: [User])
201in
185in
202− void . withConnection "host=localhost port=5432 dbname=exampledb" $
186+ withConnection "host=localhost port=5432 dbname=exampledb" $
203 define setup
187 define setup
204 & pqThen session
188 & pqThen session
205 & pqThen (define teardown)
189 & pqThen (define teardown)
206:}
190:}
207[User {userName = "Alice", userEmail = Just "alice@gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just "carole@hotmail.com"}]
191[User {userName = "Alice", userEmail = Just "alice@gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just "carole@hotmail.com"}]
208-}
192-}
209−module Squeal.PostgreSQL
193+module Squeal.PostgreSQL (module X, RenderSQL(..), printSQL) where
210− ( module Squeal.PostgreSQL.Binary
194+
211− , module Squeal.PostgreSQL.Definition
212− , module Squeal.PostgreSQL.Expression
213− , module Squeal.PostgreSQL.Manipulation
214− , module Squeal.PostgreSQL.PQ
215− , module Squeal.PostgreSQL.Query
216− , module Squeal.PostgreSQL.Schema
217− , module Squeal.PostgreSQL.Transaction
218− ) where
219−
220−import Squeal.PostgreSQL.Binary
195+import Squeal.PostgreSQL.Alias as X
196+import Squeal.PostgreSQL.Binary as X
221−import Squeal.PostgreSQL.Definition
197+import Squeal.PostgreSQL.Definition as X
198+import Squeal.PostgreSQL.Definition.Function as X
199+import Squeal.PostgreSQL.Definition.Index as X
200+import Squeal.PostgreSQL.Definition.Schema as X
201+import Squeal.PostgreSQL.Definition.Table as X
202+import Squeal.PostgreSQL.Definition.Table.Constraint as X
203+import Squeal.PostgreSQL.Definition.Type as X
204+import Squeal.PostgreSQL.Definition.View as X
222−import Squeal.PostgreSQL.Expression
205+import Squeal.PostgreSQL.Expression as X
206+import Squeal.PostgreSQL.Expression.Aggregate as X
207+import Squeal.PostgreSQL.Expression.Collection as X
208+import Squeal.PostgreSQL.Expression.Comparison as X
209+import Squeal.PostgreSQL.Expression.Json as X
210+import Squeal.PostgreSQL.Expression.Literal as X
211+import Squeal.PostgreSQL.Expression.Logic as X
212+import Squeal.PostgreSQL.Expression.Math as X
213+import Squeal.PostgreSQL.Expression.Null as X
214+import Squeal.PostgreSQL.Expression.Parameter as X
215+import Squeal.PostgreSQL.Expression.Range as X
216+import Squeal.PostgreSQL.Expression.Set as X
217+import Squeal.PostgreSQL.Expression.Sort as X
218+import Squeal.PostgreSQL.Expression.Subquery as X
219+import Squeal.PostgreSQL.Expression.Text as X
220+import Squeal.PostgreSQL.Expression.TextSearch as X
221+import Squeal.PostgreSQL.Expression.Time as X
222+import Squeal.PostgreSQL.Expression.Type as X
223+import Squeal.PostgreSQL.Expression.Window as X
224+import Squeal.PostgreSQL.List as X
223−import Squeal.PostgreSQL.Manipulation
225+import Squeal.PostgreSQL.Manipulation as X
226+import Squeal.PostgreSQL.Migration as X
227+import Squeal.PostgreSQL.PG as X
228+import Squeal.PostgreSQL.Pool as X
224−import Squeal.PostgreSQL.PQ
229+import Squeal.PostgreSQL.PQ as X
225−import Squeal.PostgreSQL.Query
230+import Squeal.PostgreSQL.Query as X
231+import Squeal.PostgreSQL.Render (RenderSQL(..), printSQL)
226−import Squeal.PostgreSQL.Schema
232+import Squeal.PostgreSQL.Schema as X
227−import Squeal.PostgreSQL.Transaction
233+import Squeal.PostgreSQL.Transaction as X
squeal-postgresql/src/Squeal/PostgreSQL/Alias.hsnew file+249
@@ -0,0 +1,249 @@
1+{-|
2+Module: Squeal.PostgreSQL.Alias
3+Description: Aliases
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+This module embeds Postgres's alias system in Haskell in
9+a typesafe fashion. Thanks to GHC's @OverloadedLabels@ extension,
10+Squeal can reference aliases by prepending with a @#@.
11+-}
12+
13+{-# LANGUAGE
14+ AllowAmbiguousTypes
15+ , ConstraintKinds
16+ , DeriveAnyClass
17+ , DeriveGeneric
18+ , FlexibleContexts
19+ , FlexibleInstances
20+ , FunctionalDependencies
21+ , GADTs
22+ , LambdaCase
23+ , OverloadedStrings
24+ , QuantifiedConstraints
25+ , RankNTypes
26+ , ScopedTypeVariables
27+ , StandaloneDeriving
28+ , TypeApplications
29+ , TypeFamilyDependencies
30+ , TypeInType
31+ , TypeOperators
32+ , UndecidableInstances
33+ , UndecidableSuperClasses
34+#-}
35+
36+module Squeal.PostgreSQL.Alias
37+ ( (:::)
38+ , Alias (..)
39+ , IsLabel (..)
40+ , Aliased (As)
41+ , Aliasable (as)
42+ , renderAliased
43+ , Has
44+ , HasUnique
45+ , HasAll
46+ , HasIn
47+ , QualifiedAlias (..)
48+ , IsQualified (..)
49+ -- * Grouping
50+ , Grouping (..)
51+ , GroupedBy
52+ ) where
53+
54+import Control.DeepSeq
55+import Data.ByteString (ByteString)
56+import Data.String (fromString)
57+import GHC.OverloadedLabels
58+import GHC.TypeLits
59+
60+import qualified Generics.SOP as SOP
61+import qualified GHC.Generics as GHC
62+
63+import Squeal.PostgreSQL.List
64+import Squeal.PostgreSQL.Render
65+
66+-- $setup
67+-- >>> import Squeal.PostgreSQL
68+
69+-- | The alias operator `:::` is like a promoted version of `As`,
70+-- a type level pair between an alias and some type.
71+type (:::) (alias :: Symbol) ty = '(alias,ty)
72+infixr 6 :::
73+
74+
75+-- | `Grouping` is an auxiliary namespace, created by
76+-- @GROUP BY@ clauses (`Squeal.PostgreSQL.Query.group`), and used
77+-- for typesafe aggregation
78+data Grouping
79+ = Ungrouped -- ^ no aggregation permitted
80+ | Grouped [(Symbol,Symbol)] -- ^ aggregation required for any column which is not grouped
81+
82+{- | A `GroupedBy` constraint indicates that a table qualified column is
83+a member of the auxiliary namespace created by @GROUP BY@ clauses and thus,
84+may be called in an output `Squeal.PostgreSQL.Expression.Expression` without aggregating.
85+-}
86+class (KnownSymbol table, KnownSymbol column)
87+ => GroupedBy table column bys where
88+instance {-# OVERLAPPING #-} (KnownSymbol table, KnownSymbol column)
89+ => GroupedBy table column ('(table,column) ': bys)
90+instance {-# OVERLAPPABLE #-}
91+ ( KnownSymbol table
92+ , KnownSymbol column
93+ , GroupedBy table column bys
94+ ) => GroupedBy table column (tabcol ': bys)
95+
96+-- | `Alias`es are proxies for a type level string or `Symbol`
97+-- and have an `IsLabel` instance so that with @-XOverloadedLabels@
98+--
99+-- >>> :set -XOverloadedLabels
100+-- >>> #foobar :: Alias "foobar"
101+-- Alias
102+data Alias (alias :: Symbol) = Alias
103+ deriving (Eq,GHC.Generic,Ord,Show,NFData)
104+instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where
105+ fromLabel = Alias
106+instance aliases ~ '[alias] => IsLabel alias (NP Alias aliases) where
107+ fromLabel = fromLabel SOP.:* Nil
108+-- | >>> printSQL (#jimbob :: Alias "jimbob")
109+-- "jimbob"
110+instance KnownSymbol alias => RenderSQL (Alias alias) where
111+ renderSQL = doubleQuoted . fromString . symbolVal
112+
113+-- >>> printSQL (#jimbob :* #kandi :: NP Alias '["jimbob", "kandi"])
114+-- "jimbob", "kandi"
115+instance SOP.All KnownSymbol aliases => RenderSQL (NP Alias aliases) where
116+ renderSQL
117+ = commaSeparated
118+ . SOP.hcollapse
119+ . SOP.hcmap (SOP.Proxy @KnownSymbol) (SOP.K . renderSQL)
120+
121+-- | The `As` operator is used to name an expression. `As` is like a demoted
122+-- version of `:::`.
123+--
124+-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)
125+-- As (Just "hello") Alias
126+data Aliased expression aliased where
127+ As
128+ :: KnownSymbol alias
129+ => expression ty
130+ -> Alias alias
131+ -> Aliased expression (alias ::: ty)
132+deriving instance Show (expression ty)
133+ => Show (Aliased expression (alias ::: ty))
134+deriving instance Eq (expression ty)
135+ => Eq (Aliased expression (alias ::: ty))
136+deriving instance Ord (expression ty)
137+ => Ord (Aliased expression (alias ::: ty))
138+instance (alias0 ~ alias1, alias0 ~ alias2, KnownSymbol alias2)
139+ => IsLabel alias0 (Aliased Alias (alias1 ::: alias2)) where
140+ fromLabel = fromLabel @alias2 `As` fromLabel @alias1
141+
142+-- | The `Aliasable` class provides a way to scrap your `Nil`s
143+-- in an `NP` list of `Aliased` expressions.
144+class KnownSymbol alias => Aliasable alias expression aliased
145+ | aliased -> expression
146+ , aliased -> alias
147+ where as :: expression -> Alias alias -> aliased
148+instance (KnownSymbol alias, aliased ~ (alias ::: ty)) => Aliasable alias
149+ (expression ty)
150+ (Aliased expression aliased)
151+ where
152+ as = As
153+instance (KnownSymbol alias, tys ~ '[alias ::: ty]) => Aliasable alias
154+ (expression ty)
155+ (NP (Aliased expression) tys)
156+ where
157+ expression `as` alias = expression `As` alias SOP.:* Nil
158+
159+-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")
160+-- >>> renderAliased renderMaybe (Just (3::Int) `As` #an_int)
161+-- "Just AS \"an_int\""
162+renderAliased
163+ :: (forall ty. expression ty -> ByteString)
164+ -> Aliased expression aliased
165+ -> ByteString
166+renderAliased render (expression `As` alias) =
167+ render expression <> " AS " <> renderSQL alias
168+
169+-- | @HasUnique alias fields field@ is a constraint that proves that
170+-- @fields@ is a singleton of @alias ::: field@.
171+type HasUnique alias fields field = fields ~ '[alias ::: field]
172+
173+-- | @Has alias fields field@ is a constraint that proves that
174+-- @fields@ has a field of @alias ::: field@, inferring @field@
175+-- from @alias@ and @fields@.
176+class KnownSymbol alias =>
177+ Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)
178+ | alias fields -> field where
179+instance {-# OVERLAPPING #-} KnownSymbol alias
180+ => Has alias (alias ::: field ': fields) field
181+instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)
182+ => Has alias (field' ': fields) field
183+
184+{-| @HasIn fields (alias ::: field)@ is a constraint that proves that
185+@fields@ has a field of @alias ::: field@. It is used in @UPDATE@s to
186+choose which subfields to update.
187+-}
188+class HasIn fields field where
189+instance (Has alias fields field) => HasIn fields (alias ::: field) where
190+
191+-- | `HasAll` extends `Has` to take lists of @aliases@ and @fields@ and infer
192+-- a list of @subfields@.
193+class
194+ ( SOP.All KnownSymbol aliases
195+ ) => HasAll
196+ (aliases :: [Symbol])
197+ (fields :: [(Symbol,kind)])
198+ (subfields :: [(Symbol,kind)])
199+ | aliases fields -> subfields where
200+instance {-# OVERLAPPING #-} HasAll '[] fields '[]
201+instance {-# OVERLAPPABLE #-}
202+ (Has alias fields field, HasAll aliases fields subfields)
203+ => HasAll (alias ': aliases) fields (alias ::: field ': subfields)
204+
205+-- | Analagous to `IsLabel`, the constraint
206+-- `IsQualified` defines `!` for a column alias qualified
207+-- by a table alias.
208+class IsQualified table column expression where
209+ (!) :: Alias table -> Alias column -> expression
210+ infixl 9 !
211+instance IsQualified table column (Alias table, Alias column) where (!) = (,)
212+
213+{-| `QualifiedAlias`es enables multi-schema support by allowing a reference
214+to a `Squeal.PostgreSQL.Schema.Table`, `Squeal.PostgreSQL.Schema.Typedef`
215+or `Squeal.PostgreSQL.Schema.View` to be qualified by their schemas. By default,
216+a qualifier of @public@ is provided.
217+
218+>>> :{
219+let
220+ alias1 :: QualifiedAlias "sch" "tab"
221+ alias1 = #sch ! #tab
222+ alias2 :: QualifiedAlias "public" "vw"
223+ alias2 = #vw
224+in printSQL alias1 >> printSQL alias2
225+:}
226+"sch"."tab"
227+"vw"
228+-}
229+data QualifiedAlias (qualifier :: Symbol) (alias :: Symbol) = QualifiedAlias
230+ deriving (Eq,GHC.Generic,Ord,Show,NFData)
231+instance (q ~ q', a ~ a') => IsQualified q a (QualifiedAlias q' a') where
232+ _!_ = QualifiedAlias
233+instance (q' ~ "public", a ~ a') => IsLabel a (QualifiedAlias q' a') where
234+ fromLabel = QualifiedAlias
235+instance (q0 ~ q1, a0 ~ a1, a1 ~ a2, KnownSymbol a2) =>
236+ IsQualified q0 a0 (Aliased (QualifiedAlias q1) (a1 ::: a2)) where
237+ _!_ = QualifiedAlias `As` Alias
238+instance (q ~ "public", a0 ~ a1, a1 ~ a2, KnownSymbol a2) =>
239+ IsLabel a0 (Aliased (QualifiedAlias q) (a1 ::: a2)) where
240+ fromLabel = QualifiedAlias `As` Alias
241+
242+instance (KnownSymbol q, KnownSymbol a)
243+ => RenderSQL (QualifiedAlias q a) where
244+ renderSQL _ =
245+ let
246+ qualifier = renderSQL (Alias @q)
247+ alias = renderSQL (Alias @a)
248+ in
249+ if qualifier == "\"public\"" then alias else qualifier <> "." <> alias
squeal-postgresql/src/Squeal/PostgreSQL/Binary.hs+534−221
@@ -7,103 +7,157 @@ Stability: experimental
7
7
8This module provides binary encoding and decoding between Haskell and PostgreSQL types.
8This module provides binary encoding and decoding between Haskell and PostgreSQL types.
9
9
10−Instances are governed by the `Generic` and `HasDatatypeInfo` typeclasses, so you absolutely
10+Instances are governed by the `SOP.Generic` and `SOP.HasDatatypeInfo` typeclasses, so you absolutely
11do not need to define your own instances to decode retrieved rows into Haskell values or
11do not need to define your own instances to decode retrieved rows into Haskell values or
12to encode Haskell values into statement parameters.
12to encode Haskell values into statement parameters.
13
13
14+Let's see some examples. We'll need some imports
15+
14>>> import Data.Int (Int16)
16>>> import Data.Int (Int16)
15>>> import Data.Text (Text)
17>>> import Data.Text (Text)
18+>>> import Control.Monad (void)
19+>>> import Control.Monad.IO.Class (liftIO)
20+>>> import Squeal.PostgreSQL
21+
22+Define a Haskell datatype @Row@ that will serve as both the input and output of a simple
23+round trip query.
16
24
17−>>> data Row = Row { col1 :: Int16, col2 :: Text } deriving (Eq, GHC.Generic)
25+>>> data Row = Row { col1 :: Int16, col2 :: Text, col3 :: Maybe Bool } deriving (Eq, GHC.Generic)
18>>> instance Generic Row
26>>> instance Generic Row
19>>> instance HasDatatypeInfo Row
27>>> instance HasDatatypeInfo Row
28+>>> :{
29+let
30+ roundTrip :: Query_ (Public '[]) Row Row
31+ roundTrip = values_ $
32+ parameter @1 int2 `as` #col1 :*
33+ parameter @2 text `as` #col2 :*
34+ parameter @3 bool `as` #col3
35+:}
20
36
21−>>> import Control.Monad (void)
37+So long as we can encode the parameters and then decode the result of the query,
22−>>> import Control.Monad.Base (liftBase)
38+the input and output should be equal.
23−>>> import Squeal.PostgreSQL
24
39
40+>>> let input = Row 2 "hi" (Just True)
25>>> :{
41>>> :{
26−let
42+withConnection "host=localhost port=5432 dbname=exampledb" $ do
27− query :: Query '[]
43+ result <- runQueryParams roundTrip input
28− '[ 'NotNull 'PGint2, 'NotNull 'PGtext]
44+ Just output <- firstRow result
29− '["col1" ::: 'NotNull 'PGint2, "col2" ::: 'NotNull 'PGtext]
45+ liftIO . print $ input == output
30− query = values_ (param @1 `As` #col1 :* param @2 `As` #col2 :* Nil)
31:}
46:}
47+True
48+
49+In addition to being able to encode and decode basic Haskell types
50+like `Int16` and `Data.Text.Text`, Squeal permits you to encode and decode Haskell types to
51+Postgres array, enumerated and composite types and json. Let's see another example,
52+this time using the `Vector` type which corresponds to variable length arrays
53+and homogeneous tuples which correspond to fixed length arrays. We can even
54+create multi-dimensional fixed length arrays.
55+
56+>>> :{
57+data Row = Row
58+ { col1 :: VarArray (Vector Int16)
59+ , col2 :: FixArray (Maybe Int16,Maybe Int16)
60+ , col3 :: FixArray ((Int16,Int16),(Int16,Int16),(Int16,Int16))
61+ } deriving (Eq, GHC.Generic)
62+:}
63+
64+>>> instance Generic Row
65+>>> instance HasDatatypeInfo Row
66+
67+Once again, we define a simple round trip query.
32
68
33>>> :{
69>>> :{
34let
70let
35− roundtrip :: IO ()
71+ roundTrip :: Query_ (Public '[]) Row Row
36− roundtrip = void . withConnection "host=localhost port=5432 dbname=exampledb" $ do
72+ roundTrip = values_ $
37− result <- runQueryParams query (2 :: Int16, "hi" :: Text)
73+ parameter @1 (int2 & vararray) `as` #col1 :*
38− Just row <- firstRow result
74+ parameter @2 (int2 & fixarray @'[2]) `as` #col2 :*
39− liftBase . print $ row == Row 2 "hi"
75+ parameter @3 (int2 & fixarray @'[3,2]) `as` #col3
40:}
76:}
41
77
42−>>> roundtrip
78+>>> :set -XOverloadedLists
79+>>> let input = Row (VarArray [1,2]) (FixArray (Just 1,Nothing)) (FixArray ((1,2),(3,4),(5,6)))
80+>>> :{
81+withConnection "host=localhost port=5432 dbname=exampledb" $ do
82+ result <- runQueryParams roundTrip input
83+ Just output <- firstRow result
84+ liftIO . print $ input == output
85+:}
43True
86True
44
87
45−In addition to being able to encode and decode basic Haskell types like `Int16` and `Text`,
46−Squeal permits you to encode and decode Haskell types which are equivalent to
47−Postgres enumerated and composite types.
48−
49Enumerated (enum) types are data types that comprise a static, ordered set of values.
88Enumerated (enum) types are data types that comprise a static, ordered set of values.
50They are equivalent to Haskell algebraic data types whose constructors are nullary.
89They are equivalent to Haskell algebraic data types whose constructors are nullary.
51An example of an enum type might be the days of the week,
90An example of an enum type might be the days of the week,
52or a set of status values for a piece of data.
91or a set of status values for a piece of data.
53
92
54−>>> data Schwarma = Beef | Lamb | Chicken deriving (Show, GHC.Generic)
93+>>> data Schwarma = Beef | Lamb | Chicken deriving (Eq, Show, GHC.Generic)
55>>> instance Generic Schwarma
94>>> instance Generic Schwarma
56>>> instance HasDatatypeInfo Schwarma
95>>> instance HasDatatypeInfo Schwarma
57
96
58A composite type represents the structure of a row or record;
97A composite type represents the structure of a row or record;
59−it is essentially just a list of field names and their data types. They are almost
98+it is essentially just a list of field names and their data types.
60−equivalent to Haskell record types. However, because of the potential presence of @NULL@
61−all the record fields must be `Maybe`s of basic types.
62
99
63−>>> data Person = Person {name :: Maybe Text, age :: Maybe Int32} deriving (Show, GHC.Generic)
100+>>> data Person = Person {name :: Text, age :: Int32} deriving (Eq, Show, GHC.Generic)
64>>> instance Generic Person
101>>> instance Generic Person
65>>> instance HasDatatypeInfo Person
102>>> instance HasDatatypeInfo Person
103+>>> instance Aeson.FromJSON Person
104+>>> instance Aeson.ToJSON Person
66
105
67We can create the equivalent Postgres types directly from their Haskell types.
106We can create the equivalent Postgres types directly from their Haskell types.
68
107
69>>> :{
108>>> :{
70type Schema =
109type Schema =
71− '[ "schwarma" ::: 'Typedef (EnumFrom Schwarma)
110+ '[ "schwarma" ::: 'Typedef (PG (Enumerated Schwarma))
72− , "person" ::: 'Typedef (CompositeFrom Person)
111+ , "person" ::: 'Typedef (PG (Composite Person))
73 ]
112 ]
74:}
113:}
75
114
76>>> :{
115>>> :{
77let
116let
78− setup :: Definition '[] Schema
117+ setup :: Definition (Public '[]) (Public Schema)
79 setup =
118 setup =
80 createTypeEnumFrom @Schwarma #schwarma >>>
119 createTypeEnumFrom @Schwarma #schwarma >>>
81 createTypeCompositeFrom @Person #person
120 createTypeCompositeFrom @Person #person
82:}
121:}
83
122
84−Then we can perform roundtrip queries;
123+Let's demonstrate how to associate our Haskell types @Schwarma@ and @Person@
124+with enumerated, composite or json types in Postgres. First create a Haskell
125+@Row@ type using the `Enumerated`, `Composite` and `Json` newtypes as fields.
85
126
127+>>> :{
128+data Row = Row
129+ { schwarma :: Enumerated Schwarma
130+ , person1 :: Composite Person
131+ , person2 :: Json Person
132+ } deriving (Eq, GHC.Generic)
133+:}
134+
135+>>> instance Generic Row
136+>>> instance HasDatatypeInfo Row
86>>> :{
137>>> :{
87let
138let
88− querySchwarma :: Query Schema
139+ input = Row
89− '[ 'NotNull (EnumFrom Schwarma)]
140+ (Enumerated Chicken)
90− '["fromOnly" ::: 'NotNull (EnumFrom Schwarma)]
141+ (Composite (Person "Faisal" 24))
91− querySchwarma = values_ (parameter @1 #schwarma `As` #fromOnly :* Nil)
142+ (Json (Person "Ahmad" 48))
92:}
143:}
93
144
145+Once again, define a round trip query.
146+
94>>> :{
147>>> :{
95let
148let
96− queryPerson :: Query Schema
149+ roundTrip :: Query_ (Public Schema) Row Row
97− '[ 'NotNull (CompositeFrom Person)]
150+ roundTrip = values_ $
98− '["fromOnly" ::: 'NotNull (CompositeFrom Person)]
151+ parameter @1 (typedef #schwarma) `as` #schwarma :*
99− queryPerson = values_ (parameter @1 #person `As` #fromOnly :* Nil)
152+ parameter @2 (typedef #person) `as` #person1 :*
153+ parameter @3 json `as` #person2
100:}
154:}
101
155
102−And finally drop the types.
156+Finally, we can drop our type definitions.
103
157
104>>> :{
158>>> :{
105let
159let
106− teardown :: Definition Schema '[]
160+ teardown :: Definition (Public Schema) (Public '[])
107 teardown = dropType #schwarma >>> dropType #person
161 teardown = dropType #schwarma >>> dropType #person
108:}
162:}
109
163
@@ -112,20 +166,16 @@ Now let's run it.
112>>> :{
166>>> :{
113let
167let
114 session = do
168 session = do
115− result1 <- runQueryParams querySchwarma (Only Chicken)
169+ result <- runQueryParams roundTrip input
116− Just (Only schwarma) <- firstRow result1
170+ Just output <- firstRow result
117− liftBase $ print (schwarma :: Schwarma)
171+ liftIO . print $ input == output
118− result2 <- runQueryParams queryPerson (Only (Person (Just "Faisal") (Just 24)))
119− Just (Only person) <- firstRow result2
120− liftBase $ print (person :: Person)
121in
172in
122− void . withConnection "host=localhost port=5432 dbname=exampledb" $
173+ withConnection "host=localhost port=5432 dbname=exampledb" $
123 define setup
174 define setup
124 & pqThen session
175 & pqThen session
125 & pqThen (define teardown)
176 & pqThen (define teardown)
126:}
177:}
127−Chicken
178+True
128−Person {name = Just "Faisal", age = Just 24}
129-}
179-}
130
180
131{-# LANGUAGE
181{-# LANGUAGE
@@ -134,55 +184,76 @@ Person {name = Just "Faisal", age = Just 24}
134 , DeriveFunctor
184 , DeriveFunctor
135 , DeriveGeneric
185 , DeriveGeneric
136 , DeriveTraversable
186 , DeriveTraversable
187+ , DefaultSignatures
137 , FlexibleContexts
188 , FlexibleContexts
138 , FlexibleInstances
189 , FlexibleInstances
190+ , FunctionalDependencies
139 , GADTs
191 , GADTs
140 , LambdaCase
192 , LambdaCase
193+ , OverloadedStrings
141 , MultiParamTypeClasses
194 , MultiParamTypeClasses
142 , ScopedTypeVariables
195 , ScopedTypeVariables
143 , TypeApplications
196 , TypeApplications
197+ , TypeFamilies
144 , TypeInType
198 , TypeInType
145 , TypeOperators
199 , TypeOperators
146 , UndecidableInstances
200 , UndecidableInstances
201+ , UndecidableSuperClasses
147#-}
202#-}
148
203
149module Squeal.PostgreSQL.Binary
204module Squeal.PostgreSQL.Binary
150 ( -- * Encoding
205 ( -- * Encoding
151 ToParam (..)
206 ToParam (..)
152− , ToColumnParam (..)
153 , ToParams (..)
207 , ToParams (..)
208+ , ToNullityParam (..)
209+ , ToField (..)
210+ , ToFixArray (..)
154 -- * Decoding
211 -- * Decoding
155 , FromValue (..)
212 , FromValue (..)
156− , FromColumnValue (..)
157 , FromRow (..)
213 , FromRow (..)
214+ , FromField (..)
215+ , FromFixArray (..)
158 -- * Only
216 -- * Only
159 , Only (..)
217 , Only (..)
218+ -- * Oid
219+ , OidOf (..)
220+ , OidOfParam (..)
221+ , OidOfField (..)
160 ) where
222 ) where
161
223
162import BinaryParser
224import BinaryParser
163−import ByteString.StrictBuilder
225+import ByteString.StrictBuilder (builderLength, int32BE, int64BE, word32BE)
164−import Data.Aeson hiding (Null)
226+import Control.Arrow (left)
227+import Control.Monad
165import Data.Int
228import Data.Int
166import Data.Kind
229import Data.Kind
167−import Data.Monoid hiding (All)
168import Data.Scientific
230import Data.Scientific
169import Data.Time
231import Data.Time
170import Data.UUID.Types
232import Data.UUID.Types
171import Data.Vector (Vector)
233import Data.Vector (Vector)
172import Data.Word
234import Data.Word
235+import Foreign.C.Types (CUInt(CUInt))
173import Generics.SOP
236import Generics.SOP
237+import Generics.SOP.Record
174import GHC.TypeLits
238import GHC.TypeLits
175import Network.IP.Addr
239import Network.IP.Addr
176
240
177−import qualified Data.ByteString.Lazy as Lazy
241+import qualified Data.Aeson as Aeson
242+import qualified Data.ByteString.Lazy as Lazy (ByteString)
178−import qualified Data.ByteString as Strict hiding (pack, unpack)
243+import qualified Data.ByteString.Lazy as Lazy.ByteString
244+import qualified Data.ByteString as Strict (ByteString)
179−import qualified Data.Text.Lazy as Lazy
245+import qualified Data.Text.Lazy as Lazy (Text)
246+import qualified Data.Text as Strict (Text)
180−import qualified Data.Text as Strict
247+import qualified Data.Text as Strict.Text
181import qualified Data.Vector as Vector
248import qualified Data.Vector as Vector
249+import qualified Database.PostgreSQL.LibPQ as LibPQ
182import qualified GHC.Generics as GHC
250import qualified GHC.Generics as GHC
183import qualified PostgreSQL.Binary.Decoding as Decoding
251import qualified PostgreSQL.Binary.Decoding as Decoding
184import qualified PostgreSQL.Binary.Encoding as Encoding
252import qualified PostgreSQL.Binary.Encoding as Encoding
185
253
254+import Squeal.PostgreSQL.Alias
255+import Squeal.PostgreSQL.List
256+import Squeal.PostgreSQL.PG
186import Squeal.PostgreSQL.Schema
257import Squeal.PostgreSQL.Schema
187
258
188-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into
259-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into
@@ -206,19 +277,20 @@ class ToParam (x :: Type) (pg :: PGType) where
206 toParam :: x -> K Encoding.Encoding pg
277 toParam :: x -> K Encoding.Encoding pg
207instance ToParam Bool 'PGbool where toParam = K . Encoding.bool
278instance ToParam Bool 'PGbool where toParam = K . Encoding.bool
208instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16
279instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16
209−instance ToParam Word16 'PGint2 where toParam = K . Encoding.int2_word16
210instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32
280instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32
211−instance ToParam Word32 'PGint4 where toParam = K . Encoding.int4_word32
212instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64
281instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64
213−instance ToParam Word64 'PGint8 where toParam = K . Encoding.int8_word64
282+instance ToParam Oid 'PGoid where toParam = K . Encoding.int4_word32 . getOid
214instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4
283instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4
215instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8
284instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8
216instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric
285instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric
286+instance ToParam Money 'PGmoney where toParam = K . Encoding.int8_int64 . cents
217instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid
287instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid
218instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet
288instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet
219instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8
289instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8
220instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict
290instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict
221instance ToParam Lazy.Text 'PGtext where toParam = K . Encoding.text_lazy
291instance ToParam Lazy.Text 'PGtext where toParam = K . Encoding.text_lazy
292+instance ToParam String 'PGtext where
293+ toParam = K . Encoding.text_strict . Strict.Text.pack
222instance ToParam Strict.ByteString 'PGbytea where
294instance ToParam Strict.ByteString 'PGbytea where
223 toParam = K . Encoding.bytea_strict
295 toParam = K . Encoding.bytea_strict
224instance ToParam Lazy.ByteString 'PGbytea where
296instance ToParam Lazy.ByteString 'PGbytea where
@@ -232,17 +304,40 @@ instance ToParam LocalTime 'PGtimestamp where
232instance ToParam UTCTime 'PGtimestamptz where
304instance ToParam UTCTime 'PGtimestamptz where
233 toParam = K . Encoding.timestamptz_int
305 toParam = K . Encoding.timestamptz_int
234instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int
306instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int
235−instance ToParam Value 'PGjson where toParam = K . Encoding.json_ast
307+instance ToParam Aeson.Value 'PGjson where toParam = K . Encoding.json_ast
236−instance ToParam Value 'PGjsonb where toParam = K . Encoding.jsonb_ast
308+instance ToParam Aeson.Value 'PGjsonb where toParam = K . Encoding.jsonb_ast
237−instance (HasOid pg, ToParam x pg)
309+instance Aeson.ToJSON x => ToParam (Json x) 'PGjson where
310+ toParam = K . Encoding.json_bytes
311+ . Lazy.ByteString.toStrict . Aeson.encode . getJson
312+instance Aeson.ToJSON x => ToParam (Jsonb x) 'PGjsonb where
313+ toParam = K . Encoding.jsonb_bytes
314+ . Lazy.ByteString.toStrict . Aeson.encode . getJsonb
315+instance (ToNullityParam x ty, ty ~ nullity pg, OidOf pg)
316+ => ToParam (VarArray [x]) ('PGvararray ty) where
317+ toParam = K
318+ . Encoding.array_foldable
319+ (getOid (oidOf @pg)) (unK . toNullityParam @x @ty)
320+ . getVarArray
321+instance (ToParam x pg, OidOf pg)
322+ => ToParam (VarArray (Vector x)) ('PGvararray ('NotNull pg)) where
323+ toParam = K
324+ . Encoding.array_vector (getOid (oidOf @pg)) (unK . toParam @x @pg)
325+ . getVarArray
326+instance (ToParam x pg, OidOf pg)
238− => ToParam (Vector (Maybe x)) ('PGvararray pg) where
327+ => ToParam (VarArray (Vector (Maybe x))) ('PGvararray ('Null pg)) where
328+ toParam = K
239− toParam = K . Encoding.nullableArray_vector
329+ . Encoding.nullableArray_vector
240− (oid @pg) (unK . toParam @x @pg)
330+ (getOid (oidOf @pg)) (unK . toParam @x @pg)
331+ . getVarArray
332+instance (ToFixArray x dims ty, ty ~ nullity pg, OidOf pg)
333+ => ToParam (FixArray x) ('PGfixarray dims ty) where
334+ toParam = K . Encoding.array (getOid (oidOf @pg))
335+ . unK . unK . toFixArray @x @dims @ty . getFixArray
241instance
336instance
242 ( IsEnumType x
337 ( IsEnumType x
243 , HasDatatypeInfo x
338 , HasDatatypeInfo x
244− , LabelsFrom x ~ labels
339+ , LabelsPG x ~ labels
245− ) => ToParam x ('PGenum labels) where
340+ ) => ToParam (Enumerated x) ('PGenum labels) where
246 toParam =
341 toParam =
247 let
342 let
248 gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String
343 gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String
@@ -253,24 +348,23 @@ instance
253 gshowConstructor constructors (SOP xs)
348 gshowConstructor constructors (SOP xs)
254 in
349 in
255 K . Encoding.text_strict
350 K . Encoding.text_strict
256− . Strict.pack
351+ . Strict.Text.pack
257 . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))
352 . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))
258 . from
353 . from
354+ . getEnumerated
259instance
355instance
260 ( SListI fields
356 ( SListI fields
261− , MapMaybes xs
357+ , IsRecord x xs
262− , IsProductType x (Maybes xs)
358+ , AllZip ToField xs fields
263− , AllZip ToAliasedParam xs fields
264− , FieldNamesFrom x ~ AliasesOf fields
265− , All HasAliasedOid fields
359+ , All OidOfField fields
266− ) => ToParam x ('PGcomposite fields) where
360+ ) => ToParam (Composite x) ('PGcomposite fields) where
267 toParam =
361 toParam =
268 let
362 let
269
363
270− encoders = htrans (Proxy @ToAliasedParam) toAliasedParam
364+ encoders = htrans (Proxy @ToField) toField
271
365
272 composite
366 composite
273− :: All HasAliasedOid row
367+ :: All OidOfField row
274 => NP (K (Maybe Encoding.Encoding)) row
368 => NP (K (Maybe Encoding.Encoding)) row
275 -> K Encoding.Encoding ('PGcomposite row)
369 -> K Encoding.Encoding ('PGcomposite row)
276 composite fields = K $
370 composite fields = K $
@@ -287,53 +381,179 @@ instance
287 int32BE (fromIntegral (lengthSList (Proxy @xs))) <>
381 int32BE (fromIntegral (lengthSList (Proxy @xs))) <>
288 let
382 let
289 each
383 each
290− :: HasAliasedOid field
384+ :: OidOfField field
291 => K (Maybe Encoding.Encoding) field
385 => K (Maybe Encoding.Encoding) field
292 -> Encoding.Encoding
386 -> Encoding.Encoding
293 each (K field :: K (Maybe Encoding.Encoding) field) =
387 each (K field :: K (Maybe Encoding.Encoding) field) =
294− word32BE (aliasedOid @field)
388+ word32BE (getOid (oidOfField @field))
295 <> case field of
389 <> case field of
296 Nothing -> int64BE (-1)
390 Nothing -> int64BE (-1)
297 Just value ->
391 Just value ->
298 int32BE (fromIntegral (builderLength value))
392 int32BE (fromIntegral (builderLength value))
299 <> value
393 <> value
300 in
394 in
301− hcfoldMap (Proxy @HasAliasedOid) each fields
395+ hcfoldMap (Proxy @OidOfField) each fields
302
396
303 in
397 in
304− composite . encoders . unMaybes . unZ . unSOP . from
398+ composite . encoders . toRecord . getComposite
305−
399+
306−class HasAliasedOid (field :: (Symbol, PGType)) where aliasedOid :: Word32
400+-- | The object identifier of a `PGType`.
307−instance HasOid ty => HasAliasedOid (alias ::: ty) where aliasedOid = oid @ty
401+--
308−
402+-- >>> :set -XTypeApplications
309−class ToAliasedParam (x :: Type) (field :: (Symbol, PGType)) where
403+-- >>> oidOf @'PGbool
310− toAliasedParam :: Maybe x -> K (Maybe Encoding.Encoding) field
404+-- Oid 16
311−instance ToParam x ty => ToAliasedParam x (alias ::: ty) where
405+class OidOf (ty :: PGType) where oidOf :: LibPQ.Oid
312− toAliasedParam = \case
406+instance OidOf 'PGbool where oidOf = LibPQ.Oid 16
313− Nothing -> K Nothing
407+instance OidOf ('PGfixarray ns (null 'PGbool)) where oidOf = LibPQ.Oid 1000
314− Just x -> K . Just . unK $ toParam @x @ty x
408+instance OidOf ('PGvararray (null 'PGbool)) where oidOf = LibPQ.Oid 1000
315−
409+instance OidOf 'PGint2 where oidOf = LibPQ.Oid 21
316−-- | A `ToColumnParam` constraint lifts the `ToParam` encoding
410+instance OidOf ('PGfixarray ns (null 'PGint2)) where oidOf = LibPQ.Oid 1005
317−-- of a `Type` to a `NullityType`, encoding `Maybe`s to `Null`s. You should
411+instance OidOf ('PGvararray (null 'PGint2)) where oidOf = LibPQ.Oid 1005
318−-- not define instances of `ToColumnParam`, just use the provided instances.
412+instance OidOf 'PGint4 where oidOf = LibPQ.Oid 23
319−class ToColumnParam (x :: Type) (ty :: NullityType) where
413+instance OidOf ('PGfixarray ns (null 'PGint4)) where oidOf = LibPQ.Oid 1007
320− -- | >>> toColumnParam @Int16 @('NotNull 'PGint2) 0
414+instance OidOf ('PGvararray (null 'PGint4)) where oidOf = LibPQ.Oid 1007
321− -- K (Just "\NUL\NUL")
415+instance OidOf 'PGint8 where oidOf = LibPQ.Oid 20
322− --
416+instance OidOf ('PGfixarray ns (null 'PGint8)) where oidOf = LibPQ.Oid 1016
323− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) (Just 0)
417+instance OidOf ('PGvararray (null 'PGint8)) where oidOf = LibPQ.Oid 1016
324− -- K (Just "\NUL\NUL")
418+instance OidOf 'PGnumeric where oidOf = LibPQ.Oid 1700
325− --
419+instance OidOf ('PGfixarray ns (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231
326− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) Nothing
420+instance OidOf ('PGvararray (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231
327− -- K Nothing
421+instance OidOf 'PGfloat4 where oidOf = LibPQ.Oid 700
328− toColumnParam :: x -> K (Maybe Strict.ByteString) ty
422+instance OidOf ('PGfixarray ns (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021
329−instance ToParam x pg => ToColumnParam x ('NotNull pg) where
423+instance OidOf ('PGvararray (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021
330− toColumnParam = K . Just . Encoding.encodingBytes . unK . toParam @x @pg
424+instance OidOf 'PGfloat8 where oidOf = LibPQ.Oid 701
331−instance ToParam x pg => ToColumnParam (Maybe x) ('Null pg) where
425+instance OidOf ('PGfixarray ns (null 'PGfloat8)) where oidOf = LibPQ.Oid 1022
332− toColumnParam = K . fmap (Encoding.encodingBytes . unK . toParam @x @pg)
426+instance OidOf ('PGvararray (null 'PGfloat8)) where oidOf = LibPQ.Oid 1022
427+instance OidOf 'PGmoney where oidOf = LibPQ.Oid 790
428+instance OidOf ('PGfixarray ns (null 'PGmoney)) where oidOf = LibPQ.Oid 791
429+instance OidOf ('PGvararray (null 'PGmoney)) where oidOf = LibPQ.Oid 791
430+instance OidOf ('PGchar n) where oidOf = LibPQ.Oid 18
431+instance OidOf ('PGfixarray ns (null ('PGchar n))) where oidOf = LibPQ.Oid 1002
432+instance OidOf ('PGvararray (null ('PGchar n))) where oidOf = LibPQ.Oid 1002
433+instance OidOf ('PGvarchar n) where oidOf = LibPQ.Oid 1043
434+instance OidOf ('PGfixarray ns (null ('PGvarchar n))) where oidOf = LibPQ.Oid 1015
435+instance OidOf ('PGvararray (null ('PGvarchar n))) where oidOf = LibPQ.Oid 1015
436+instance OidOf 'PGtext where oidOf = LibPQ.Oid 25
437+instance OidOf ('PGfixarray ns (null 'PGtext)) where oidOf = LibPQ.Oid 1009
438+instance OidOf ('PGvararray (null 'PGtext)) where oidOf = LibPQ.Oid 1009
439+instance OidOf 'PGbytea where oidOf = LibPQ.Oid 17
440+instance OidOf ('PGfixarray ns (null 'PGbytea)) where oidOf = LibPQ.Oid 1001
441+instance OidOf ('PGvararray (null 'PGbytea)) where oidOf = LibPQ.Oid 1001
442+instance OidOf 'PGtimestamp where oidOf = LibPQ.Oid 1114
443+instance OidOf ('PGfixarray ns (null 'PGtimestamp)) where oidOf = LibPQ.Oid 1115
444+instance OidOf ('PGvararray (null 'PGtimestamp)) where oidOf = LibPQ.Oid 1115
445+instance OidOf 'PGtimestamptz where oidOf = LibPQ.Oid 1184
446+instance OidOf ('PGfixarray ns (null 'PGtimestamptz)) where oidOf = LibPQ.Oid 1185
447+instance OidOf ('PGvararray (null 'PGtimestamptz)) where oidOf = LibPQ.Oid 1185
448+instance OidOf 'PGdate where oidOf = LibPQ.Oid 1082
449+instance OidOf ('PGfixarray ns (null 'PGdate)) where oidOf = LibPQ.Oid 1182
450+instance OidOf ('PGvararray (null 'PGdate)) where oidOf = LibPQ.Oid 1182
451+instance OidOf 'PGtime where oidOf = LibPQ.Oid 1083
452+instance OidOf ('PGfixarray ns (null 'PGtime)) where oidOf = LibPQ.Oid 1183
453+instance OidOf ('PGvararray (null 'PGtime)) where oidOf = LibPQ.Oid 1183
454+instance OidOf 'PGtimetz where oidOf = LibPQ.Oid 1266
455+instance OidOf ('PGfixarray ns (null 'PGtimetz)) where oidOf = LibPQ.Oid 1270
456+instance OidOf ('PGvararray (null 'PGtimetz)) where oidOf = LibPQ.Oid 1270
457+instance OidOf 'PGinterval where oidOf = LibPQ.Oid 1186
458+instance OidOf ('PGfixarray ns (null 'PGinterval)) where oidOf = LibPQ.Oid 1187
459+instance OidOf ('PGvararray (null 'PGinterval)) where oidOf = LibPQ.Oid 1187
460+instance OidOf 'PGuuid where oidOf = LibPQ.Oid 2950
461+instance OidOf ('PGfixarray ns (null 'PGuuid)) where oidOf = LibPQ.Oid 2951
462+instance OidOf ('PGvararray (null 'PGuuid)) where oidOf = LibPQ.Oid 2951
463+instance OidOf 'PGinet where oidOf = LibPQ.Oid 869
464+instance OidOf ('PGfixarray ns (null 'PGinet)) where oidOf = LibPQ.Oid 1041
465+instance OidOf ('PGvararray (null 'PGinet)) where oidOf = LibPQ.Oid 1041
466+instance OidOf 'PGjson where oidOf = LibPQ.Oid 114
467+instance OidOf ('PGfixarray ns (null 'PGjson)) where oidOf = LibPQ.Oid 199
468+instance OidOf ('PGvararray (null 'PGjson)) where oidOf = LibPQ.Oid 199
469+instance OidOf 'PGjsonb where oidOf = LibPQ.Oid 3802
470+instance OidOf ('PGfixarray ns (null 'PGjsonb)) where oidOf = LibPQ.Oid 3807
471+instance OidOf ('PGvararray (null 'PGjsonb)) where oidOf = LibPQ.Oid 3807
472+instance OidOf 'PGtsvector where oidOf = LibPQ.Oid 3614
473+instance OidOf ('PGfixarray ns (null 'PGtsvector)) where oidOf = LibPQ.Oid 3643
474+instance OidOf ('PGvararray (null 'PGtsvector)) where oidOf = LibPQ.Oid 3643
475+instance OidOf 'PGtsquery where oidOf = LibPQ.Oid 3615
476+instance OidOf ('PGfixarray ns (null 'PGtsquery)) where oidOf = LibPQ.Oid 3645
477+instance OidOf ('PGvararray (null 'PGtsquery)) where oidOf = LibPQ.Oid 3645
478+instance OidOf 'PGoid where oidOf = LibPQ.Oid 26
479+instance OidOf ('PGfixarray ns (null 'PGoid)) where oidOf = LibPQ.Oid 1028
480+instance OidOf ('PGvararray (null 'PGoid)) where oidOf = LibPQ.Oid 1028
481+instance OidOf ('PGrange 'PGint4) where oidOf = LibPQ.Oid 3904
482+instance OidOf ('PGfixarray ns (null ('PGrange 'PGint4))) where oidOf = LibPQ.Oid 3905
483+instance OidOf ('PGvararray (null ('PGrange 'PGint4))) where oidOf = LibPQ.Oid 3905
484+instance OidOf ('PGrange 'PGint8) where oidOf = LibPQ.Oid 3926
485+instance OidOf ('PGfixarray ns (null ('PGrange 'PGint8))) where oidOf = LibPQ.Oid 3927
486+instance OidOf ('PGvararray (null ('PGrange 'PGint8))) where oidOf = LibPQ.Oid 3927
487+instance OidOf ('PGrange 'PGnumeric) where oidOf = LibPQ.Oid 3906
488+instance OidOf ('PGfixarray ns (null ('PGrange 'PGnumeric))) where oidOf = LibPQ.Oid 3907
489+instance OidOf ('PGvararray (null ('PGrange 'PGnumeric))) where oidOf = LibPQ.Oid 3907
490+instance OidOf ('PGrange 'PGtimestamp) where oidOf = LibPQ.Oid 3908
491+instance OidOf ('PGfixarray ns (null ('PGrange 'PGtimestamp))) where oidOf = LibPQ.Oid 3909
492+instance OidOf ('PGvararray (null ('PGrange 'PGtimestamp))) where oidOf = LibPQ.Oid 3909
493+instance OidOf ('PGrange 'PGtimestamptz) where oidOf = LibPQ.Oid 3910
494+instance OidOf ('PGfixarray ns (null ('PGrange 'PGtimestamptz))) where oidOf = LibPQ.Oid 3911
495+instance OidOf ('PGvararray (null ('PGrange 'PGtimestamptz))) where oidOf = LibPQ.Oid 3911
496+instance OidOf ('PGrange 'PGdate) where oidOf = LibPQ.Oid 3912
497+instance OidOf ('PGfixarray ns (null ('PGrange 'PGdate))) where oidOf = LibPQ.Oid 3913
498+instance OidOf ('PGvararray (null ('PGrange 'PGdate))) where oidOf = LibPQ.Oid 3913
499+instance {-# OVERLAPPABLE #-} OidOf ('PGrange ty) where oidOf = LibPQ.invalidOid
500+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGrange ty))) where oidOf = LibPQ.invalidOid
501+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGrange ty))) where oidOf = LibPQ.invalidOid
502+instance {-# OVERLAPPABLE #-} OidOf ('PGcomposite row) where oidOf = LibPQ.invalidOid
503+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGcomposite row))) where oidOf = LibPQ.invalidOid
504+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGcomposite row))) where oidOf = LibPQ.invalidOid
505+instance {-# OVERLAPPABLE #-} OidOf ('PGenum labels) where oidOf = LibPQ.invalidOid
506+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGenum labels))) where oidOf = LibPQ.invalidOid
507+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGenum labels))) where oidOf = LibPQ.invalidOid
508+
509+class OidOfParam (ty :: NullityType) where oidOfParam :: Oid
510+instance OidOf ty => OidOfParam (null ty) where oidOfParam = oidOf @ty
511+
512+-- | Lifts a `OidOf` constraint to a field.
513+class OidOfField (field :: (Symbol, NullityType)) where
514+ oidOfField :: Oid
515+instance OidOf ty => OidOfField (alias ::: nullity ty) where
516+ oidOfField = oidOf @ty
517+
518+-- | A `ToNullityParam` constraint gives an encoding of a Haskell `Type` into
519+-- into the binary format of a PostgreSQL `NullityType`.
520+class ToNullityParam (x :: Type) (ty :: NullityType) where
521+ toNullityParam :: x -> K (Maybe Encoding.Encoding) ty
522+instance ToParam x pg => ToNullityParam x ('NotNull pg) where
523+ toNullityParam = K . Just . unK . toParam @x @pg
524+instance ToParam x pg => ToNullityParam (Maybe x) ('Null pg) where
525+ toNullityParam = K . fmap (unK . toParam @x @pg)
526+
527+-- | A `ToField` constraint lifts the `ToParam` parser
528+-- to an encoding of a @(Symbol, Type)@ to a @(Symbol, NullityType)@,
529+-- encoding `Null`s to `Maybe`s. You should not define instances for
530+-- `FromField`, just use the provided instances.
531+class ToField (x :: (Symbol, Type)) (field :: (Symbol, NullityType)) where
532+ toField :: P x -> K (Maybe Encoding.Encoding) field
533+instance ToNullityParam x ty => ToField (alias ::: x) (alias ::: ty) where
534+ toField (P x) = K . unK $ toNullityParam @x @ty x
535+
536+-- | A `ToFixArray` constraint gives an encoding of a Haskell `Type`
537+-- into the binary format of a PostgreSQL fixed-length array.
538+-- You should not define instances for
539+-- `ToFixArray`, just use the provided instances.
540+class ToFixArray (x :: Type) (dims :: [Nat]) (array :: NullityType) where
541+ toFixArray :: x -> K (K Encoding.Array dims) array
542+instance ToNullityParam x ty => ToFixArray x '[] ty where
543+ toFixArray = K . K . maybe Encoding.nullArray Encoding.encodingArray . unK
544+ . toNullityParam @x @ty
545+instance
546+ ( IsProductType product xs
547+ , Length xs ~ dim
548+ , All ((~) x) xs
549+ , ToFixArray x dims ty )
550+ => ToFixArray product (dim ': dims) ty where
551+ toFixArray = K . K . Encoding.dimensionArray foldlN
552+ (unK . unK . toFixArray @x @dims @ty) . unZ . unSOP . from
333
553
334-- | A `ToParams` constraint generically sequences the encodings of `Type`s
554-- | A `ToParams` constraint generically sequences the encodings of `Type`s
335-- of the fields of a tuple or record to a row of `ColumnType`s. You should
555-- of the fields of a tuple or record to a row of `ColumnType`s. You should
336−-- not define instances of `ToParams`. Instead define `Generic` instances
556+-- not define instances of `ToParams`. Instead define `SOP.Generic` instances
337-- which in turn provide `ToParams` instances.
557-- which in turn provide `ToParams` instances.
338class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where
558class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where
339 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]
559 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]
@@ -345,61 +565,98 @@ class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where
345 -- >>> instance Generic Tuple
565 -- >>> instance Generic Tuple
346 -- >>> toParams @Tuple @Params (Tuple False (Just 0))
566 -- >>> toParams @Tuple @Params (Tuple False (Just 0))
347 -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil
567 -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil
348− toParams :: x -> NP (K (Maybe Strict.ByteString)) tys
568+ toParams :: x -> NP (K (Maybe Encoding.Encoding)) tys
349−instance (SListI tys, IsProductType x xs, AllZip ToColumnParam xs tys)
569+instance (SListI tys, IsProductType x xs, AllZip ToNullityParam xs tys)
350 => ToParams x tys where
570 => ToParams x tys where
351 toParams
571 toParams
352− = htrans (Proxy @ToColumnParam) (toColumnParam . unI)
572+ = htrans (Proxy @ToNullityParam) (toNullityParam . unI)
353 . unZ . unSOP . from
573 . unZ . unSOP . from
354
574
355-- | A `FromValue` constraint gives a parser from the binary format of
575-- | A `FromValue` constraint gives a parser from the binary format of
356-- a PostgreSQL `PGType` into a Haskell `Type`.
576-- a PostgreSQL `PGType` into a Haskell `Type`.
357class FromValue (pg :: PGType) (y :: Type) where
577class FromValue (pg :: PGType) (y :: Type) where
358 -- | >>> newtype Id = Id { getId :: Int16 } deriving Show
578 -- | >>> newtype Id = Id { getId :: Int16 } deriving Show
359− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue
579+ -- >>> instance FromValue 'PGint2 Id where fromValue = Id <$> fromValue @'PGint2
360− fromValue :: proxy pg -> Decoding.Value y
580+ fromValue :: Decoding.Value y
361−instance FromValue 'PGbool Bool where fromValue _ = Decoding.bool
581+instance FromValue 'PGbool Bool where fromValue = Decoding.bool
362−instance FromValue 'PGint2 Int16 where fromValue _ = Decoding.int
582+instance FromValue 'PGint2 Int16 where fromValue = Decoding.int
363−instance FromValue 'PGint4 Int32 where fromValue _ = Decoding.int
583+instance FromValue 'PGint4 Int32 where fromValue = Decoding.int
364−instance FromValue 'PGint8 Int64 where fromValue _ = Decoding.int
584+instance FromValue 'PGint8 Int64 where fromValue = Decoding.int
585+instance FromValue 'PGoid Word32 where fromValue = Decoding.int
365−instance FromValue 'PGfloat4 Float where fromValue _ = Decoding.float4
586+instance FromValue 'PGfloat4 Float where fromValue = Decoding.float4
366−instance FromValue 'PGfloat8 Double where fromValue _ = Decoding.float8
587+instance FromValue 'PGfloat8 Double where fromValue = Decoding.float8
367−instance FromValue 'PGnumeric Scientific where fromValue _ = Decoding.numeric
588+instance FromValue 'PGnumeric Scientific where fromValue = Decoding.numeric
589+instance FromValue 'PGmoney Money where fromValue = Money <$> Decoding.int
368−instance FromValue 'PGuuid UUID where fromValue _ = Decoding.uuid
590+instance FromValue 'PGuuid UUID where fromValue = Decoding.uuid
369−instance FromValue 'PGinet (NetAddr IP) where fromValue _ = Decoding.inet
591+instance FromValue 'PGinet (NetAddr IP) where fromValue = Decoding.inet
370−instance FromValue ('PGchar 1) Char where fromValue _ = Decoding.char
592+instance FromValue ('PGchar 1) Char where fromValue = Decoding.char
371−instance FromValue 'PGtext Strict.Text where fromValue _ = Decoding.text_strict
593+instance FromValue 'PGtext Strict.Text where fromValue = Decoding.text_strict
372−instance FromValue 'PGtext Lazy.Text where fromValue _ = Decoding.text_lazy
594+instance FromValue 'PGtext Lazy.Text where fromValue = Decoding.text_lazy
595+instance FromValue 'PGtext String where
596+ fromValue = Strict.Text.unpack <$> Decoding.text_strict
373instance FromValue 'PGbytea Strict.ByteString where
597instance FromValue 'PGbytea Strict.ByteString where
374− fromValue _ = Decoding.bytea_strict
598+ fromValue = Decoding.bytea_strict
375instance FromValue 'PGbytea Lazy.ByteString where
599instance FromValue 'PGbytea Lazy.ByteString where
376− fromValue _ = Decoding.bytea_lazy
600+ fromValue = Decoding.bytea_lazy
377−instance FromValue 'PGdate Day where fromValue _ = Decoding.date
601+instance FromValue 'PGdate Day where fromValue = Decoding.date
378−instance FromValue 'PGtime TimeOfDay where fromValue _ = Decoding.time_int
602+instance FromValue 'PGtime TimeOfDay where fromValue = Decoding.time_int
379instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where
603instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where
380− fromValue _ = Decoding.timetz_int
604+ fromValue = Decoding.timetz_int
381instance FromValue 'PGtimestamp LocalTime where
605instance FromValue 'PGtimestamp LocalTime where
382− fromValue _ = Decoding.timestamp_int
606+ fromValue = Decoding.timestamp_int
383instance FromValue 'PGtimestamptz UTCTime where
607instance FromValue 'PGtimestamptz UTCTime where
384− fromValue _ = Decoding.timestamptz_int
608+ fromValue = Decoding.timestamptz_int
385instance FromValue 'PGinterval DiffTime where
609instance FromValue 'PGinterval DiffTime where
386− fromValue _ = Decoding.interval_int
610+ fromValue = Decoding.interval_int
387−instance FromValue 'PGjson Value where fromValue _ = Decoding.json_ast
611+instance FromValue 'PGjson Aeson.Value where fromValue = Decoding.json_ast
388−instance FromValue 'PGjsonb Value where fromValue _ = Decoding.jsonb_ast
612+instance FromValue 'PGjsonb Aeson.Value where fromValue = Decoding.jsonb_ast
613+instance Aeson.FromJSON x => FromValue 'PGjson (Json x) where
614+ fromValue = Json <$>
615+ Decoding.json_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)
616+instance Aeson.FromJSON x => FromValue 'PGjsonb (Jsonb x) where
617+ fromValue = Jsonb <$>
618+ Decoding.jsonb_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)
619+instance FromValue pg y
389−instance FromValue pg y => FromValue ('PGvararray pg) (Vector (Maybe y)) where
620+ => FromValue ('PGvararray ('NotNull pg)) (VarArray (Vector y)) where
390− fromValue _ = Decoding.array
621+ fromValue =
622+ let
623+ rep n x = VarArray <$> Vector.replicateM n x
624+ in
391− (Decoding.dimensionArray Vector.replicateM
625+ Decoding.array $ Decoding.dimensionArray rep
392− (Decoding.nullableValueArray (fromValue (Proxy @pg))))
626+ (fromFixArray @'[] @('NotNull pg))
627+instance FromValue pg y
628+ => FromValue ('PGvararray ('Null pg)) (VarArray (Vector (Maybe y))) where
629+ fromValue =
630+ let
631+ rep n x = VarArray <$> Vector.replicateM n x
632+ in
633+ Decoding.array $ Decoding.dimensionArray rep
634+ (fromFixArray @'[] @('Null pg))
635+instance FromValue pg y
636+ => FromValue ('PGvararray ('NotNull pg)) (VarArray [y]) where
637+ fromValue =
638+ let
639+ rep n x = VarArray <$> replicateM n x
640+ in
641+ Decoding.array $ Decoding.dimensionArray rep
642+ (fromFixArray @'[] @('NotNull pg))
643+instance FromValue pg y
644+ => FromValue ('PGvararray ('Null pg)) (VarArray [Maybe y]) where
645+ fromValue =
646+ let
647+ rep n x = VarArray <$> replicateM n x
648+ in
649+ Decoding.array $ Decoding.dimensionArray rep
650+ (fromFixArray @'[] @('Null pg))
651+instance FromFixArray dims ty y
393−instance FromValue pg y => FromValue ('PGfixarray n pg) (Vector (Maybe y)) where
652+ => FromValue ('PGfixarray dims ty) (FixArray y) where
394− fromValue _ = Decoding.array
653+ fromValue = FixArray <$> Decoding.array (fromFixArray @dims @ty @y)
395− (Decoding.dimensionArray Vector.replicateM
396− (Decoding.nullableValueArray (fromValue (Proxy @pg))))
397instance
654instance
398 ( IsEnumType y
655 ( IsEnumType y
399 , HasDatatypeInfo y
656 , HasDatatypeInfo y
400− , LabelsFrom y ~ labels
657+ , LabelsPG y ~ labels
401− ) => FromValue ('PGenum labels) y where
658+ ) => FromValue ('PGenum labels) (Enumerated y) where
402− fromValue _ =
659+ fromValue =
403 let
660 let
404 greadConstructor
661 greadConstructor
405 :: All ((~) '[]) xss
662 :: All ((~) '[]) xss
@@ -412,29 +669,16 @@ instance
412 then Just (SOP (Z Nil))
669 then Just (SOP (Z Nil))
413 else SOP . S . unSOP <$> greadConstructor constructors name
670 else SOP . S . unSOP <$> greadConstructor constructors name
414 in
671 in
672+ fmap Enumerated
415− Decoding.enum
673+ . Decoding.enum
416 $ fmap to
674 $ fmap to
417 . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))
675 . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))
418− . Strict.unpack
676+ . Strict.Text.unpack
419−
420instance
677instance
421− ( SListI fields
678+ ( FromRow fields y
422− , MapMaybes ys
423− , IsProductType y (Maybes ys)
424− , AllZip FromAliasedValue fields ys
425− , FieldNamesFrom y ~ AliasesOf fields
426− ) => FromValue ('PGcomposite fields) y where
679+ ) => FromValue ('PGcomposite fields) (Composite y) where
427 fromValue =
680 fromValue =
428 let
681 let
429− decoders
430− :: forall pgs zs proxy
431− . AllZip FromAliasedValue pgs zs
432− => proxy ('PGcomposite pgs)
433− -> NP Decoding.Value zs
434− decoders _ = htrans (Proxy @FromAliasedValue) fromAliasedValue
435− (hpure Proxy :: NP Proxy pgs)
436−
437− composite fields = do
438 -- <number of fields: 4 bytes>
682 -- <number of fields: 4 bytes>
439 -- [for each field]
683 -- [for each field]
440 -- <OID of field's type: sizeof(Oid) bytes>
684 -- <OID of field's type: sizeof(Oid) bytes>
@@ -445,80 +689,133 @@ instance
445 -- <value: <length> bytes>
689 -- <value: <length> bytes>
446 -- [end if]
690 -- [end if]
447 -- [end for]
691 -- [end for]
692+ composite = Decoding.valueParser $ do
448 unitOfSize 4
693 unitOfSize 4
449− let
694+ hsequence' $ hpure $ Comp $ do
450− each field = do
451− unitOfSize 4
695+ unitOfSize 4
452− len <- sized 4 Decoding.int
696+ len <- sized 4 Decoding.int
697+ if len == -1
453− if len == -1 then return Nothing else Just <$> sized len field
698+ then return (K Nothing)
454− htraverse' each fields
699+ else K . Just <$> bytesOfSize len
455−
700+ in
456− in fmap (to . SOP . Z . maybes) . composite . decoders
701+ fmap Composite (Decoding.fn (fromRow @fields <=< composite))
457−
458−class FromAliasedValue (pg :: (Symbol,PGType)) (y :: Type) where
459− fromAliasedValue :: proxy pg -> Decoding.Value y
460−instance FromValue pg y => FromAliasedValue (alias ::: pg) y where
461− fromAliasedValue _ = fromValue (Proxy @pg)
462
702
463−-- | A `FromColumnValue` constraint lifts the `FromValue` parser
703+-- | A `FromField` constraint lifts the `FromValue` parser
464-- to a decoding of a @(Symbol, NullityType)@ to a `Type`,
704-- to a decoding of a @(Symbol, NullityType)@ to a `Type`,
465-- decoding `Null`s to `Maybe`s. You should not define instances for
705-- decoding `Null`s to `Maybe`s. You should not define instances for
466−-- `FromColumnValue`, just use the provided instances.
706+-- `FromField`, just use the provided instances.
467−class FromColumnValue (colty :: (Symbol,NullityType)) (y :: Type) where
707+class FromField (pg :: (Symbol, NullityType)) (y :: (Symbol, Type)) where
468− -- | >>> :set -XTypeOperators -XOverloadedStrings
708+ fromField
469− -- >>> newtype Id = Id { getId :: Int16 } deriving Show
470− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue
471− -- >>> fromColumnValue @("col" ::: 'NotNull 'PGint2) @Id (K (Just "\NUL\SOH"))
472− -- Id {getId = 1}
473− --
474− -- >>> fromColumnValue @("col" ::: 'Null 'PGint2) @(Maybe Id) (K (Just "\NUL\SOH"))
475− -- Just (Id {getId = 1})
476− fromColumnValue :: K (Maybe Strict.ByteString) colty -> y
709+ :: K (Maybe Strict.ByteString) pg
710+ -> (Either Strict.Text :.: P) y
477instance FromValue pg y
711instance FromValue pg y
478− => FromColumnValue (column ::: ('NotNull pg)) y where
712+ => FromField (column ::: ('NotNull pg)) (column ::: y) where
479− fromColumnValue = \case
713+ fromField = Comp . \case
480− K Nothing -> error "fromColumnValue: saw NULL when expecting NOT NULL"
714+ K Nothing -> Left "fromField: saw NULL when expecting NOT NULL"
481− K (Just bs) ->
715+ K (Just bytestring) -> P <$>
482− let
483− errOrValue =
484− Decoding.valueParser (fromValue @pg @y Proxy) bs
716+ Decoding.valueParser (fromValue @pg) bytestring
485− err str = error $ "fromColumnValue: " ++ Strict.unpack str
486− in
487− either err id errOrValue
488instance FromValue pg y
717instance FromValue pg y
489− => FromColumnValue (column ::: ('Null pg)) (Maybe y) where
718+ => FromField (column ::: 'Null pg) (column ::: Maybe y) where
490− fromColumnValue (K nullOrBytes)
719+ fromField = Comp . \case
491− = either err id
720+ K Nothing -> Right $ P Nothing
492− . Decoding.valueParser (fromValue @pg @y Proxy)
721+ K (Just bytestring) -> P . Just <$>
493− <$> nullOrBytes
722+ Decoding.valueParser (fromValue @pg) bytestring
494− where
723+
495− err str = error $ "fromColumnValue: " ++ Strict.unpack str
724+-- | A `FromFixArray` constraint gives a decoding to a Haskell `Type`
725+-- from the binary format of a PostgreSQL fixed-length array.
726+-- You should not define instances for
727+-- `FromFixArray`, just use the provided instances.
728+class FromFixArray (dims :: [Nat]) (ty :: NullityType) (y :: Type) where
729+ fromFixArray :: Decoding.Array y
730+instance FromValue pg y => FromFixArray '[] ('NotNull pg) y where
731+ fromFixArray = Decoding.valueArray (fromValue @pg @y)
732+instance FromValue pg y => FromFixArray '[] ('Null pg) (Maybe y) where
733+ fromFixArray = Decoding.nullableValueArray (fromValue @pg @y)
734+instance
735+ ( IsProductType product ys
736+ , Length ys ~ dim
737+ , All ((~) y) ys
738+ , FromFixArray dims ty y )
739+ => FromFixArray (dim ': dims) ty product where
740+ fromFixArray =
741+ let
742+ rep _ = fmap (to . SOP . Z) . replicateMN
743+ in
744+ Decoding.dimensionArray rep (fromFixArray @dims @ty @y)
496
745
497-- | A `FromRow` constraint generically sequences the parsings of the columns
746-- | A `FromRow` constraint generically sequences the parsings of the columns
498−-- of a `RelationType` into the fields of a record `Type` provided they have
747+-- of a `RowType` into the fields of a record `Type` provided they have
499-- the same field names. You should not define instances of `FromRow`.
748-- the same field names. You should not define instances of `FromRow`.
500−-- Instead define `Generic` and `HasDatatypeInfo` instances which in turn
749+-- Instead define `SOP.Generic` and `SOP.HasDatatypeInfo` instances which in turn
501-- provide `FromRow` instances.
750-- provide `FromRow` instances.
502−class SListI results => FromRow (results :: RelationType) y where
751+class SListI result => FromRow (result :: RowType) y where
503 -- | >>> :set -XOverloadedStrings
752 -- | >>> :set -XOverloadedStrings
504 -- >>> import Data.Text
753 -- >>> import Data.Text
505 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show
754 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show
506− -- >>> instance FromValue 'PGint2 UserId where fromValue = fmap UserId . fromValue
755+ -- >>> instance FromValue 'PGint2 UserId where fromValue = UserId <$> fromValue @'PGint2
507 -- >>> data UserRow = UserRow { userId :: UserId, userName :: Maybe Text } deriving (Show, GHC.Generic)
756 -- >>> data UserRow = UserRow { userId :: UserId, userName :: Maybe Text } deriving (Show, GHC.Generic)
508 -- >>> instance Generic UserRow
757 -- >>> instance Generic UserRow
509 -- >>> instance HasDatatypeInfo UserRow
758 -- >>> instance HasDatatypeInfo UserRow
510 -- >>> type User = '["userId" ::: 'NotNull 'PGint2, "userName" ::: 'Null 'PGtext]
759 -- >>> type User = '["userId" ::: 'NotNull 'PGint2, "userName" ::: 'Null 'PGtext]
511 -- >>> fromRow @User @UserRow (K (Just "\NUL\SOH") :* K (Just "bloodninja") :* Nil)
760 -- >>> fromRow @User @UserRow (K (Just "\NUL\SOH") :* K (Just "bloodninja") :* Nil)
512− -- UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"}
761+ -- Right (UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"})
513− fromRow :: NP (K (Maybe Strict.ByteString)) results -> y
762+ fromRow :: NP (K (Maybe Strict.ByteString)) result -> Either Strict.Text y
514instance
763instance
515− ( SListI results
764+ ( SListI result
516− , IsProductType y ys
765+ , IsRecord y ys
517− , AllZip FromColumnValue results ys
766+ , AllZip FromField result ys
518− , FieldNamesFrom y ~ AliasesOf results
519− ) => FromRow results y where
767+ ) => FromRow result y where
520 fromRow
768 fromRow
521− = to . SOP . Z . htrans (Proxy @FromColumnValue) (I . fromColumnValue)
769+ = fmap fromRecord
770+ . hsequence'
771+ . htrans (Proxy @FromField) fromField
772+------------------------------------------------------
773+-- P records
774+------------------------------------------------------
775+-- instance (FromField (col ::: pg) (col ::: hask))
776+-- => FromRow '[col ::: pg] (P (col ::: hask)) where
777+-- fromRow (pg :* Nil) = (unComp . fromField) pg
778+-- instance
779+-- ( row ~ Join row1 row2
780+-- , FromRow row1 hask1
781+-- , FromRow row2 hask2
782+-- , SListI row
783+-- ) => FromRow row (hask1, hask2) where
784+-- fromRow row = case disjoin @row1 @row2 row of
785+-- (row1, row2) -> (,) <$> fromRow row1 <*> fromRow row2
786+-- instance
787+-- ( row ~ Join row1 row23
788+-- , FromRow row1 hask1
789+-- , FromRow row23 (hask2, hask3)
790+-- , SListI row
791+-- ) => FromRow row (hask1, hask2, hask3) where
792+-- fromRow row = case disjoin @row1 @row23 row of
793+-- (row1, row23) -> do
794+-- hask1 <- fromRow row1
795+-- (hask2, hask3) <- fromRow row23
796+-- return (hask1, hask2, hask3)
797+-- instance
798+-- ( row ~ Join row1 row234
799+-- , FromRow row1 hask1
800+-- , FromRow row234 (hask2, hask3, hask4)
801+-- , SListI row
802+-- ) => FromRow row (hask1, hask2, hask3, hask4) where
803+-- fromRow row = case disjoin @row1 @row234 row of
804+-- (row1, row234) -> do
805+-- hask1 <- fromRow row1
806+-- (hask2, hask3, hask4) <- fromRow row234
807+-- return (hask1, hask2, hask3, hask4)
808+-- instance
809+-- ( row ~ Join row1 row2345
810+-- , FromRow row1 hask1
811+-- , FromRow row2345 (hask2, hask3, hask4, hask5)
812+-- , SListI row
813+-- ) => FromRow row (hask1, hask2, hask3, hask4, hask5) where
814+-- fromRow row = case disjoin @row1 @row2345 row of
815+-- (row1, row2345) -> do
816+-- hask1 <- fromRow row1
817+-- (hask2, hask3, hask4, hask5) <- fromRow row2345
818+-- return (hask1, hask2, hask3, hask4, hask5)
522
819
523-- | `Only` is a 1-tuple type, useful for encoding a single parameter with
820-- | `Only` is a 1-tuple type, useful for encoding a single parameter with
524-- `toParams` or decoding a single value with `fromRow`.
821-- `toParams` or decoding a single value with `fromRow`.
@@ -528,8 +825,24 @@ instance
528-- K (Just "foo") :* Nil
825-- K (Just "foo") :* Nil
529--
826--
530-- >>> fromRow @'["fromOnly" ::: 'Null 'PGtext] @(Only (Maybe Text)) (K (Just "bar") :* Nil)
827-- >>> fromRow @'["fromOnly" ::: 'Null 'PGtext] @(Only (Maybe Text)) (K (Just "bar") :* Nil)
531−-- Only {fromOnly = Just "bar"}
828+-- Right (Only {fromOnly = Just "bar"})
532newtype Only x = Only { fromOnly :: x }
829newtype Only x = Only { fromOnly :: x }
533 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)
830 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)
534instance Generic (Only x)
831instance Generic (Only x)
535instance HasDatatypeInfo (Only x)
832instance HasDatatypeInfo (Only x)
833+
834+foldlN
835+ :: All ((~) x) xs
836+ => (z -> x -> z) -> z -> NP I xs -> z
837+foldlN f z = \case
838+ Nil -> z
839+ I x :* xs -> let z' = f z x in seq z' $ foldlN f z' xs
840+
841+replicateMN
842+ :: forall x xs m. (All ((~) x) xs, Monad m, SListI xs)
843+ => m x -> m (NP I xs)
844+replicateMN mx = hsequence' $
845+ hcpure (Proxy :: Proxy ((~) x)) (Comp (I <$> mx))
846+
847+getOid :: LibPQ.Oid -> Word32
848+getOid (LibPQ.Oid (CUInt oid)) = oid
squeal-postgresql/src/Squeal/PostgreSQL/Definition.hs+23−893
@@ -11,13 +11,15 @@ Squeal data definition language.
11{-# LANGUAGE
11{-# LANGUAGE
12 AllowAmbiguousTypes
12 AllowAmbiguousTypes
13 , ConstraintKinds
13 , ConstraintKinds
14+ , DeriveAnyClass
14 , DeriveGeneric
15 , DeriveGeneric
16+ , DerivingStrategies
15 , FlexibleContexts
17 , FlexibleContexts
16 , FlexibleInstances
18 , FlexibleInstances
17 , GADTs
19 , GADTs
18− , GeneralizedNewtypeDeriving
19 , LambdaCase
20 , LambdaCase
20 , MultiParamTypeClasses
21 , MultiParamTypeClasses
22+ , OverloadedLabels
21 , OverloadedStrings
23 , OverloadedStrings
22 , RankNTypes
24 , RankNTypes
23 , ScopedTypeVariables
25 , ScopedTypeVariables
@@ -25,928 +27,56 @@ Squeal data definition language.
25 , TypeInType
27 , TypeInType
26 , TypeOperators
28 , TypeOperators
27 , UndecidableSuperClasses
29 , UndecidableSuperClasses
30+ , UndecidableInstances
28#-}
31#-}
29
32
30module Squeal.PostgreSQL.Definition
33module Squeal.PostgreSQL.Definition
31 ( -- * Definition
34 ( -- * Definition
32− Definition (UnsafeDefinition, renderDefinition)
35+ Definition (..)
33 , (>>>)
36 , (>>>)
34− -- * Tables
37+ , manipDefinition
35− -- ** Create
36− , createTable
37− , createTableIfNotExists
38− , TableConstraintExpression (..)
39− , check
40− , unique
41− , primaryKey
42− , foreignKey
43− , ForeignKeyed
44− , OnDeleteClause (OnDeleteNoAction, OnDeleteRestrict, OnDeleteCascade)
45− , renderOnDeleteClause
46− , OnUpdateClause (OnUpdateNoAction, OnUpdateRestrict, OnUpdateCascade)
47− , renderOnUpdateClause
48− -- ** Drop
49− , dropTable
50− -- ** Alter
51− , alterTable
52− , alterTableRename
53− , AlterTable (UnsafeAlterTable, renderAlterTable)
54− , addConstraint
55− , dropConstraint
56− , AddColumn (addColumn)
57− , dropColumn
58− , renameColumn
59− , alterColumn
60− , AlterColumn (UnsafeAlterColumn, renderAlterColumn)
61− , setDefault
62− , dropDefault
63− , setNotNull
64− , dropNotNull
65− , alterType
66− -- * Views
67− , createView
68− , dropView
69− -- * Types
70− , createTypeEnum
71− , createTypeEnumFrom
72− , createTypeComposite
73− , createTypeCompositeFrom
74− , dropType
75− -- * Columns
76− , ColumnTypeExpression (..)
77− , nullable
78− , notNullable
79− , default_
80− , serial2
81− , smallserial
82− , serial4
83− , serial
84− , serial8
85− , bigserial
86 ) where
38 ) where
87
39
88import Control.Category
40import Control.Category
89import Control.DeepSeq
41import Control.DeepSeq
90import Data.ByteString
42import Data.ByteString
91import Data.Monoid
43import Data.Monoid
92−import GHC.TypeLits
93import Prelude hiding ((.), id)
44import Prelude hiding ((.), id)
94
45
95−import qualified Generics.SOP as SOP
96import qualified GHC.Generics as GHC
46import qualified GHC.Generics as GHC
97
47
98−import Squeal.PostgreSQL.Expression
48+import Squeal.PostgreSQL.Manipulation
99−import Squeal.PostgreSQL.Query
100import Squeal.PostgreSQL.Render
49import Squeal.PostgreSQL.Render
101import Squeal.PostgreSQL.Schema
50import Squeal.PostgreSQL.Schema
102
51
52+-- $setup
53+-- >>> import Squeal.PostgreSQL
54+
103{-----------------------------------------
55{-----------------------------------------
104statements
56statements
105-----------------------------------------}
57-----------------------------------------}
106
58
107−-- | A `Definition` is a statement that changes the schema of the
59+-- | A `Definition` is a statement that changes the schemas of the
108-- database, like a `createTable`, `dropTable`, or `alterTable` command.
60-- database, like a `createTable`, `dropTable`, or `alterTable` command.
109-- `Definition`s may be composed using the `>>>` operator.
61-- `Definition`s may be composed using the `>>>` operator.
110newtype Definition
62newtype Definition
111− (schema0 :: SchemaType)
63+ (schemas0 :: SchemasType)
112− (schema1 :: SchemaType)
64+ (schemas1 :: SchemasType)
113 = UnsafeDefinition { renderDefinition :: ByteString }
65 = UnsafeDefinition { renderDefinition :: ByteString }
114 deriving (GHC.Generic,Show,Eq,Ord,NFData)
66 deriving (GHC.Generic,Show,Eq,Ord,NFData)
115
67
116−instance RenderSQL (Definition schema0 schema1) where
68+instance RenderSQL (Definition schemas0 schemas1) where
117 renderSQL = renderDefinition
69 renderSQL = renderDefinition
118
70
119instance Category Definition where
71instance Category Definition where
120 id = UnsafeDefinition ";"
72 id = UnsafeDefinition ";"
121 ddl1 . ddl0 = UnsafeDefinition $
73 ddl1 . ddl0 = UnsafeDefinition $
122− renderDefinition ddl0 <> "\n" <> renderDefinition ddl1
74+ renderSQL ddl0 <> "\n" <> renderSQL ddl1
123−
75+
124−{-----------------------------------------
76+-- | A `Manipulation` without input or output can be run as a statement
125−CREATE statements
77+-- along with other `Definition`s, by embedding it using `manipDefinition`.
126−-----------------------------------------}
78+manipDefinition
127−
79+ :: Manipulation '[] schemas '[] '[]
128−{- | `createTable` adds a table to the schema.
80+ -- ^ no input or output
129−
81+ -> Definition schemas schemas
130−>>> :set -XOverloadedLabels
82+manipDefinition = UnsafeDefinition . (<> ";") . renderSQL
131−>>> :{
132−printSQL $
133− createTable #tab ((int & nullable) `As` #a :* (real & nullable) `As` #b :* Nil) Nil
134−:}
135−CREATE TABLE "tab" ("a" int NULL, "b" real NULL);
136−-}
137−createTable
138− :: ( KnownSymbol table
139− , columns ~ (col ': cols)
140− , SOP.SListI columns
141− , SOP.SListI constraints
142− , schema1 ~ Create table ('Table (constraints :=> columns)) schema0 )
143− => Alias table -- ^ the name of the table to add
144− -> NP (Aliased (ColumnTypeExpression schema0)) columns
145− -- ^ the names and datatype of each column
146− -> NP (Aliased (TableConstraintExpression schema1 table)) constraints
147− -- ^ constraints that must hold for the table
148− -> Definition schema0 schema1
149−createTable tab columns constraints = UnsafeDefinition $
150− "CREATE TABLE" <+> renderCreation tab columns constraints
151−
152−{-| `createTableIfNotExists` creates a table if it doesn't exist, but does not add it to the schema.
153−Instead, the schema already has the table so if the table did not yet exist, the schema was wrong.
154−`createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in
155−the `Category` of `Definition`s.
156−
157−>>> :set -XOverloadedLabels -XTypeApplications
158−>>> type Table = '[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGfloat4]
159−>>> type Schema = '["tab" ::: 'Table Table]
160−>>> :{
161−let
162− setup :: Definition Schema Schema
163− setup = createTableIfNotExists #tab ((int & nullable) `As` #a :* (real & nullable) `As` #b :* Nil) Nil
164−in printSQL setup
165−:}
166−CREATE TABLE IF NOT EXISTS "tab" ("a" int NULL, "b" real NULL);
167−-}
168−createTableIfNotExists
169− :: ( Has table schema ('Table (constraints :=> columns))
170− , SOP.SListI columns
171− , SOP.SListI constraints )
172− => Alias table -- ^ the name of the table to add
173− -> NP (Aliased (ColumnTypeExpression schema)) columns
174− -- ^ the names and datatype of each column
175− -> NP (Aliased (TableConstraintExpression schema table)) constraints
176− -- ^ constraints that must hold for the table
177− -> Definition schema schema
178−createTableIfNotExists tab columns constraints = UnsafeDefinition $
179− "CREATE TABLE IF NOT EXISTS"
180− <+> renderCreation tab columns constraints
181−
182−-- helper function for `createTable` and `createTableIfNotExists`
183−renderCreation
184− :: ( KnownSymbol table
185− , SOP.SListI columns
186− , SOP.SListI constraints )
187− => Alias table -- ^ the name of the table to add
188− -> NP (Aliased (ColumnTypeExpression schema0)) columns
189− -- ^ the names and datatype of each column
190− -> NP (Aliased (TableConstraintExpression schema1 table)) constraints
191− -- ^ constraints that must hold for the table
192− -> ByteString
193−renderCreation tab columns constraints = renderAlias tab
194− <+> parenthesized
195− ( renderCommaSeparated renderColumnDef columns
196− <> ( case constraints of
197− Nil -> ""
198− _ -> ", " <>
199− renderCommaSeparated renderConstraint constraints ) )
200− <> ";"
201− where
202− renderColumnDef :: Aliased (ColumnTypeExpression schema) x -> ByteString
203− renderColumnDef (ty `As` column) =
204− renderAlias column <+> renderColumnTypeExpression ty
205− renderConstraint
206− :: Aliased (TableConstraintExpression schema columns) constraint
207− -> ByteString
208− renderConstraint (constraint `As` alias) =
209− "CONSTRAINT" <+> renderAlias alias <+> renderTableConstraintExpression constraint
210−
211−-- | Data types are a way to limit the kind of data that can be stored in a
212−-- table. For many applications, however, the constraint they provide is
213−-- too coarse. For example, a column containing a product price should
214−-- probably only accept positive values. But there is no standard data type
215−-- that accepts only positive numbers. Another issue is that you might want
216−-- to constrain column data with respect to other columns or rows.
217−-- For example, in a table containing product information,
218−-- there should be only one row for each product number.
219−-- `TableConstraint`s give you as much control over the data in your tables
220−-- as you wish. If a user attempts to store data in a column that would
221−-- violate a constraint, an error is raised. This applies
222−-- even if the value came from the default value definition.
223−newtype TableConstraintExpression
224− (schema :: SchemaType)
225− (table :: Symbol)
226− (tableConstraint :: TableConstraint)
227− = UnsafeTableConstraintExpression
228− { renderTableConstraintExpression :: ByteString }
229− deriving (GHC.Generic,Show,Eq,Ord,NFData)
230−
231−{-| A `check` constraint is the most generic `TableConstraint` type.
232−It allows you to specify that the value in a certain column must satisfy
233−a Boolean (truth-value) expression.
234−
235−>>> :{
236−type Schema = '[
237− "tab" ::: 'Table ('[ "inequality" ::: 'Check '["a","b"]] :=> '[
238− "a" ::: 'NoDef :=> 'NotNull 'PGint4,
239− "b" ::: 'NoDef :=> 'NotNull 'PGint4
240− ])]
241−:}
242−
243−>>> :{
244−let
245− definition :: Definition '[] Schema
246− definition = createTable #tab
247− ( (int & notNullable) `As` #a :*
248− (int & notNullable) `As` #b :* Nil )
249− ( check (#a :* #b :* Nil) (#a .> #b) `As` #inequality :* Nil )
250−:}
251−
252−>>> printSQL definition
253−CREATE TABLE "tab" ("a" int NOT NULL, "b" int NOT NULL, CONSTRAINT "inequality" CHECK (("a" > "b")));
254−-}
255−check
256− :: ( Has alias schema ('Table table)
257− , HasAll aliases (TableToRelation table) subcolumns )
258− => NP Alias aliases
259− -- ^ specify the subcolumns which are getting checked
260− -> (forall tab. Condition schema '[tab ::: subcolumns] 'Ungrouped '[])
261− -- ^ a closed `Condition` on those subcolumns
262− -> TableConstraintExpression schema alias ('Check aliases)
263−check _cols condition = UnsafeTableConstraintExpression $
264− "CHECK" <+> parenthesized (renderExpression condition)
265−
266−{-| A `unique` constraint ensure that the data contained in a column,
267−or a group of columns, is unique among all the rows in the table.
268−
269−>>> :{
270−type Schema = '[
271− "tab" ::: 'Table( '[ "uq_a_b" ::: 'Unique '["a","b"]] :=> '[
272− "a" ::: 'NoDef :=> 'Null 'PGint4,
273− "b" ::: 'NoDef :=> 'Null 'PGint4
274− ])]
275−:}
276−
277−>>> :{
278−let
279− definition :: Definition '[] Schema
280− definition = createTable #tab
281− ( (int & nullable) `As` #a :*
282− (int & nullable) `As` #b :* Nil )
283− ( unique (#a :* #b :* Nil) `As` #uq_a_b :* Nil )
284−:}
285−
286−>>> printSQL definition
287−CREATE TABLE "tab" ("a" int NULL, "b" int NULL, CONSTRAINT "uq_a_b" UNIQUE ("a", "b"));
288−-}
289−unique
290− :: ( Has alias schema ('Table table)
291− , HasAll aliases (TableToRelation table) subcolumns )
292− => NP Alias aliases
293− -- ^ specify subcolumns which together are unique for each row
294− -> TableConstraintExpression schema alias ('Unique aliases)
295−unique columns = UnsafeTableConstraintExpression $
296− "UNIQUE" <+> parenthesized (commaSeparated (renderAliases columns))
297−
298−{-| A `primaryKey` constraint indicates that a column, or group of columns,
299−can be used as a unique identifier for rows in the table.
300−This requires that the values be both unique and not null.
301−
302−>>> :{
303−type Schema = '[
304− "tab" ::: 'Table ('[ "pk_id" ::: 'PrimaryKey '["id"]] :=> '[
305− "id" ::: 'Def :=> 'NotNull 'PGint4,
306− "name" ::: 'NoDef :=> 'NotNull 'PGtext
307− ])]
308−:}
309−
310−>>> :{
311−let
312− definition :: Definition '[] Schema
313− definition = createTable #tab
314− ( serial `As` #id :*
315− (text & notNullable) `As` #name :* Nil )
316− ( primaryKey #id `As` #pk_id :* Nil )
317−:}
318−
319−>>> printSQL definition
320−CREATE TABLE "tab" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_id" PRIMARY KEY ("id"));
321−-}
322−primaryKey
323− :: ( Has alias schema ('Table table)
324− , HasAll aliases (TableToColumns table) subcolumns
325− , AllNotNull subcolumns )
326− => NP Alias aliases
327− -- ^ specify the subcolumns which together form a primary key.
328− -> TableConstraintExpression schema alias ('PrimaryKey aliases)
329−primaryKey columns = UnsafeTableConstraintExpression $
330− "PRIMARY KEY" <+> parenthesized (commaSeparated (renderAliases columns))
331−
332−{-| A `foreignKey` specifies that the values in a column
333−(or a group of columns) must match the values appearing in some row of
334−another table. We say this maintains the referential integrity
335−between two related tables.
336−
337−>>> :{
338−type Schema =
339− '[ "users" ::: 'Table (
340− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
341− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
342− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
343− ])
344− , "emails" ::: 'Table (
345− '[ "pk_emails" ::: 'PrimaryKey '["id"]
346− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
347− ] :=>
348− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
349− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
350− , "email" ::: 'NoDef :=> 'Null 'PGtext
351− ])
352− ]
353−:}
354−
355−>>> :{
356−let
357− setup :: Definition '[] Schema
358− setup =
359− createTable #users
360− ( serial `As` #id :*
361− (text & notNullable) `As` #name :* Nil )
362− ( primaryKey #id `As` #pk_users :* Nil ) >>>
363− createTable #emails
364− ( serial `As` #id :*
365− (int & notNullable) `As` #user_id :*
366− (text & nullable) `As` #email :* Nil )
367− ( primaryKey #id `As` #pk_emails :*
368− foreignKey #user_id #users #id
369− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
370−in printSQL setup
371−:}
372−CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));
373−CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);
374−
375−A `foreignKey` can even be a table self-reference.
376−
377−>>> :{
378−type Schema =
379− '[ "employees" ::: 'Table (
380− '[ "employees_pk" ::: 'PrimaryKey '["id"]
381− , "employees_employer_fk" ::: 'ForeignKey '["employer_id"] "employees" '["id"]
382− ] :=>
383− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
384− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
385− , "employer_id" ::: 'NoDef :=> 'Null 'PGint4
386− ])
387− ]
388−:}
389−
390−>>> :{
391−let
392− setup :: Definition '[] Schema
393− setup =
394− createTable #employees
395− ( serial `As` #id :*
396− (text & notNullable) `As` #name :*
397− (integer & nullable) `As` #employer_id :* Nil )
398− ( primaryKey #id `As` #employees_pk :*
399− foreignKey #employer_id #employees #id
400− OnDeleteCascade OnUpdateCascade `As` #employees_employer_fk :* Nil )
401−in printSQL setup
402−:}
403−CREATE TABLE "employees" ("id" serial, "name" text NOT NULL, "employer_id" integer NULL, CONSTRAINT "employees_pk" PRIMARY KEY ("id"), CONSTRAINT "employees_employer_fk" FOREIGN KEY ("employer_id") REFERENCES "employees" ("id") ON DELETE CASCADE ON UPDATE CASCADE);
404−-}
405−foreignKey
406− :: (ForeignKeyed schema child parent
407− table reftable
408− columns refcolumns
409− constraints cols
410− reftys tys )
411− => NP Alias columns
412− -- ^ column or columns in the table
413− -> Alias parent
414− -- ^ reference table
415− -> NP Alias refcolumns
416− -- ^ reference column or columns in the reference table
417− -> OnDeleteClause
418− -- ^ what to do when reference is deleted
419− -> OnUpdateClause
420− -- ^ what to do when reference is updated
421− -> TableConstraintExpression schema child
422− ('ForeignKey columns parent refcolumns)
423−foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $
424− "FOREIGN KEY" <+> parenthesized (commaSeparated (renderAliases keys))
425− <+> "REFERENCES" <+> renderAlias parent
426− <+> parenthesized (commaSeparated (renderAliases refs))
427− <+> renderOnDeleteClause ondel
428− <+> renderOnUpdateClause onupd
429−
430−-- | A constraint synonym between types involved in a foreign key constraint.
431−type ForeignKeyed schema
432− child parent
433− table reftable
434− columns refcolumns
435− constraints cols
436− reftys tys =
437− ( Has child schema ('Table table)
438− , Has parent schema ('Table reftable)
439− , HasAll columns (TableToColumns table) tys
440− , reftable ~ (constraints :=> cols)
441− , HasAll refcolumns cols reftys
442− , SOP.AllZip SamePGType tys reftys
443− , Uniquely refcolumns constraints )
444−
445−-- | `OnDeleteClause` indicates what to do with rows that reference a deleted row.
446−data OnDeleteClause
447− = OnDeleteNoAction
448− -- ^ if any referencing rows still exist when the constraint is checked,
449− -- an error is raised
450− | OnDeleteRestrict -- ^ prevents deletion of a referenced row
451− | OnDeleteCascade
452− -- ^ specifies that when a referenced row is deleted,
453− -- row(s) referencing it should be automatically deleted as well
454− deriving (GHC.Generic,Show,Eq,Ord)
455−instance NFData OnDeleteClause
456−
457−-- | Render `OnDeleteClause`.
458−renderOnDeleteClause :: OnDeleteClause -> ByteString
459−renderOnDeleteClause = \case
460− OnDeleteNoAction -> "ON DELETE NO ACTION"
461− OnDeleteRestrict -> "ON DELETE RESTRICT"
462− OnDeleteCascade -> "ON DELETE CASCADE"
463−
464−-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked
465−-- when a referenced column is changed (updated).
466−data OnUpdateClause
467− = OnUpdateNoAction
468− -- ^ if any referencing rows has not changed when the constraint is checked,
469− -- an error is raised
470− | OnUpdateRestrict -- ^ prevents update of a referenced row
471− | OnUpdateCascade
472− -- ^ the updated values of the referenced column(s) should be copied
473− -- into the referencing row(s)
474− deriving (GHC.Generic,Show,Eq,Ord)
475−instance NFData OnUpdateClause
476−
477−-- | Render `OnUpdateClause`.
478−renderOnUpdateClause :: OnUpdateClause -> ByteString
479−renderOnUpdateClause = \case
480− OnUpdateNoAction -> "ON UPDATE NO ACTION"
481− OnUpdateRestrict -> "ON UPDATE RESTRICT"
482− OnUpdateCascade -> "ON UPDATE CASCADE"
483−
484−{-----------------------------------------
485−DROP statements
486−-----------------------------------------}
487−
488−-- | `dropTable` removes a table from the schema.
489−--
490−-- >>> :{
491−-- let
492−-- definition :: Definition '["muh_table" ::: 'Table t] '[]
493−-- definition = dropTable #muh_table
494−-- :}
495−--
496−-- >>> printSQL definition
497−-- DROP TABLE "muh_table";
498−dropTable
499− :: Has table schema ('Table t)
500− => Alias table -- ^ table to remove
501− -> Definition schema (Drop table schema)
502−dropTable tab = UnsafeDefinition $ "DROP TABLE" <+> renderAlias tab <> ";"
503−
504−{-----------------------------------------
505−ALTER statements
506−-----------------------------------------}
507−
508−-- | `alterTable` changes the definition of a table from the schema.
509−alterTable
510− :: KnownSymbol alias
511− => Alias alias -- ^ table to alter
512− -> AlterTable alias table schema -- ^ alteration to perform
513− -> Definition schema (Alter alias ('Table table) schema)
514−alterTable tab alteration = UnsafeDefinition $
515− "ALTER TABLE"
516− <+> renderAlias tab
517− <+> renderAlterTable alteration
518− <> ";"
519−
520−-- | `alterTableRename` changes the name of a table from the schema.
521−--
522−-- >>> printSQL $ alterTableRename #foo #bar
523−-- ALTER TABLE "foo" RENAME TO "bar";
524−alterTableRename
525− :: (KnownSymbol table0, KnownSymbol table1)
526− => Alias table0 -- ^ table to rename
527− -> Alias table1 -- ^ what to rename it
528− -> Definition schema (Rename table0 table1 schema)
529−alterTableRename table0 table1 = UnsafeDefinition $
530− "ALTER TABLE" <+> renderAlias table0
531− <+> "RENAME TO" <+> renderAlias table1 <> ";"
532−
533−-- | An `AlterTable` describes the alteration to perform on the columns
534−-- of a table.
535−newtype AlterTable
536− (alias :: Symbol)
537− (table :: TableType)
538− (schema :: SchemaType) =
539− UnsafeAlterTable {renderAlterTable :: ByteString}
540− deriving (GHC.Generic,Show,Eq,Ord,NFData)
541−
542−-- | An `addConstraint` adds a table constraint.
543−--
544−-- >>> :{
545−-- let
546−-- definition :: Definition
547−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]
548−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]
549−-- definition = alterTable #tab (addConstraint #positive (check (#col :* Nil) (#col .> 0)))
550−-- in printSQL definition
551−-- :}
552−-- ALTER TABLE "tab" ADD CONSTRAINT "positive" CHECK (("col" > 0));
553−addConstraint
554− :: ( KnownSymbol alias
555− , Has tab schema ('Table table0)
556− , table0 ~ (constraints :=> columns)
557− , table1 ~ (Create alias constraint constraints :=> columns) )
558− => Alias alias
559− -> TableConstraintExpression schema tab constraint
560− -- ^ constraint to add
561− -> AlterTable tab table1 schema
562−addConstraint alias constraint = UnsafeAlterTable $
563− "ADD" <+> "CONSTRAINT" <+> renderAlias alias
564− <+> renderTableConstraintExpression constraint
565−
566−-- | A `dropConstraint` drops a table constraint.
567−--
568−-- >>> :{
569−-- let
570−-- definition :: Definition
571−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]
572−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]
573−-- definition = alterTable #tab (dropConstraint #positive)
574−-- in printSQL definition
575−-- :}
576−-- ALTER TABLE "tab" DROP CONSTRAINT "positive";
577−dropConstraint
578− :: ( KnownSymbol constraint
579− , Has tab schema ('Table table0)
580− , table0 ~ (constraints :=> columns)
581− , table1 ~ (Drop constraint constraints :=> columns) )
582− => Alias constraint
583− -- ^ constraint to drop
584− -> AlterTable tab table1 schema
585−dropConstraint constraint = UnsafeAlterTable $
586− "DROP" <+> "CONSTRAINT" <+> renderAlias constraint
587−
588−-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.
589−class AddColumn ty where
590− -- | `addColumn` adds a new column, initially filled with whatever
591− -- default value is given or with @NULL@.
592− --
593− -- >>> :{
594− -- let
595− -- definition :: Definition
596− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]
597− -- '["tab" ::: 'Table ('[] :=>
598− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
599− -- , "col2" ::: 'Def :=> 'Null 'PGtext ])]
600− -- definition = alterTable #tab (addColumn #col2 (text & nullable & default_ "foo"))
601− -- in printSQL definition
602− -- :}
603− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL DEFAULT E'foo';
604− --
605− -- >>> :{
606− -- let
607− -- definition :: Definition
608− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]
609− -- '["tab" ::: 'Table ('[] :=>
610− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
611− -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]
612− -- definition = alterTable #tab (addColumn #col2 (text & nullable))
613− -- in printSQL definition
614− -- :}
615− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL;
616− addColumn
617− :: ( KnownSymbol column
618− , Has tab schema ('Table table0)
619− , table0 ~ (constraints :=> columns)
620− , table1 ~ (constraints :=> Create column ty columns) )
621− => Alias column -- ^ column to add
622− -> ColumnTypeExpression schema ty -- ^ type of the new column
623− -> AlterTable tab table1 schema
624− addColumn column ty = UnsafeAlterTable $
625− "ADD COLUMN" <+> renderAlias column <+> renderColumnTypeExpression ty
626−instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)
627−instance {-# OVERLAPPABLE #-} AddColumn ('NoDef :=> 'Null ty)
628−
629−-- | A `dropColumn` removes a column. Whatever data was in the column
630−-- disappears. Table constraints involving the column are dropped, too.
631−-- However, if the column is referenced by a foreign key constraint of
632−-- another table, PostgreSQL will not silently drop that constraint.
633−--
634−-- >>> :{
635−-- let
636−-- definition :: Definition
637−-- '["tab" ::: 'Table ('[] :=>
638−-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
639−-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]
640−-- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]
641−-- definition = alterTable #tab (dropColumn #col2)
642−-- in printSQL definition
643−-- :}
644−-- ALTER TABLE "tab" DROP COLUMN "col2";
645−dropColumn
646− :: ( KnownSymbol column
647− , Has tab schema ('Table table0)
648− , table0 ~ (constraints :=> columns)
649− , table1 ~ (constraints :=> Drop column columns) )
650− => Alias column -- ^ column to remove
651− -> AlterTable tab table1 schema
652−dropColumn column = UnsafeAlterTable $
653− "DROP COLUMN" <+> renderAlias column
654−
655−-- | A `renameColumn` renames a column.
656−--
657−-- >>> :{
658−-- let
659−-- definition :: Definition
660−-- '["tab" ::: 'Table ('[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4])]
661−-- '["tab" ::: 'Table ('[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4])]
662−-- definition = alterTable #tab (renameColumn #foo #bar)
663−-- in printSQL definition
664−-- :}
665−-- ALTER TABLE "tab" RENAME COLUMN "foo" TO "bar";
666−renameColumn
667− :: ( KnownSymbol column0
668− , KnownSymbol column1
669− , Has tab schema ('Table table0)
670− , table0 ~ (constraints :=> columns)
671− , table1 ~ (constraints :=> Rename column0 column1 columns) )
672− => Alias column0 -- ^ column to rename
673− -> Alias column1 -- ^ what to rename the column
674− -> AlterTable tab table1 schema
675−renameColumn column0 column1 = UnsafeAlterTable $
676− "RENAME COLUMN" <+> renderAlias column0 <+> "TO" <+> renderAlias column1
677−
678−-- | An `alterColumn` alters a single column.
679−alterColumn
680− :: ( KnownSymbol column
681− , Has tab schema ('Table table0)
682− , table0 ~ (constraints :=> columns)
683− , Has column columns ty0
684− , tables1 ~ (constraints :=> Alter column ty1 columns))
685− => Alias column -- ^ column to alter
686− -> AlterColumn schema ty0 ty1 -- ^ alteration to perform
687− -> AlterTable tab table1 schema
688−alterColumn column alteration = UnsafeAlterTable $
689− "ALTER COLUMN" <+> renderAlias column <+> renderAlterColumn alteration
690−
691−-- | An `AlterColumn` describes the alteration to perform on a single column.
692−newtype AlterColumn (schema :: SchemaType) (ty0 :: ColumnType) (ty1 :: ColumnType) =
693− UnsafeAlterColumn {renderAlterColumn :: ByteString}
694− deriving (GHC.Generic,Show,Eq,Ord,NFData)
695−
696−-- | A `setDefault` sets a new default for a column. Note that this doesn't
697−-- affect any existing rows in the table, it just changes the default for
698−-- future insert and update commands.
699−--
700−-- >>> :{
701−-- let
702−-- definition :: Definition
703−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
704−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]
705−-- definition = alterTable #tab (alterColumn #col (setDefault 5))
706−-- in printSQL definition
707−-- :}
708−-- ALTER TABLE "tab" ALTER COLUMN "col" SET DEFAULT 5;
709−setDefault
710− :: Expression schema '[] 'Ungrouped '[] ty -- ^ default value to set
711− -> AlterColumn schema (constraint :=> ty) ('Def :=> ty)
712−setDefault expression = UnsafeAlterColumn $
713− "SET DEFAULT" <+> renderExpression expression
714−
715−-- | A `dropDefault` removes any default value for a column.
716−--
717−-- >>> :{
718−-- let
719−-- definition :: Definition
720−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]
721−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
722−-- definition = alterTable #tab (alterColumn #col dropDefault)
723−-- in printSQL definition
724−-- :}
725−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP DEFAULT;
726−dropDefault :: AlterColumn schema ('Def :=> ty) ('NoDef :=> ty)
727−dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"
728−
729−-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.
730−-- The constraint will be checked immediately, so the table data must satisfy
731−-- the constraint before it can be added.
732−--
733−-- >>> :{
734−-- let
735−-- definition :: Definition
736−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
737−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]
738−-- definition = alterTable #tab (alterColumn #col setNotNull)
739−-- in printSQL definition
740−-- :}
741−-- ALTER TABLE "tab" ALTER COLUMN "col" SET NOT NULL;
742−setNotNull
743− :: AlterColumn schema (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)
744−setNotNull = UnsafeAlterColumn $ "SET NOT NULL"
745−
746−-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.
747−--
748−-- >>> :{
749−-- let
750−-- definition :: Definition
751−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]
752−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
753−-- definition = alterTable #tab (alterColumn #col dropNotNull)
754−-- in printSQL definition
755−-- :}
756−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP NOT NULL;
757−dropNotNull
758− :: AlterColumn schema (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)
759−dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"
760−
761−-- | An `alterType` converts a column to a different data type.
762−-- This will succeed only if each existing entry in the column can be
763−-- converted to the new type by an implicit cast.
764−--
765−-- >>> :{
766−-- let
767−-- definition :: Definition
768−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]
769−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]
770−-- definition =
771−-- alterTable #tab (alterColumn #col (alterType (numeric & notNullable)))
772−-- in printSQL definition
773−-- :}
774−-- ALTER TABLE "tab" ALTER COLUMN "col" TYPE numeric NOT NULL;
775−alterType :: ColumnTypeExpression schema ty -> AlterColumn schema ty0 ty
776−alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty
777−
778−-- | Create a view.
779−--
780−-- >>> :{
781−-- let
782−-- definition :: Definition
783−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]
784−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])
785−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]
786−-- definition =
787−-- createView #bc (select (#b :* #c :* Nil) (from (table #abc)))
788−-- in printSQL definition
789−-- :}
790−-- CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";
791−createView
792− :: KnownSymbol view
793− => Alias view -- ^ the name of the view to add
794− -> Query schema '[] relation
795− -- ^ query
796− -> Definition schema (Create view ('View relation) schema)
797−createView alias query = UnsafeDefinition $
798− "CREATE" <+> "VIEW" <+> renderAlias alias <+> "AS"
799− <+> renderQuery query <> ";"
800−
801−-- | Drop a view.
802−--
803−-- >>> :{
804−-- let
805−-- definition :: Definition
806−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])
807−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]
808−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]
809−-- definition = dropView #bc
810−-- in printSQL definition
811−-- :}
812−-- DROP VIEW "bc";
813−dropView
814− :: Has view schema ('View v)
815− => Alias view -- ^ view to remove
816− -> Definition schema (Drop view schema)
817−dropView v = UnsafeDefinition $ "DROP VIEW" <+> renderAlias v <> ";"
818−
819−-- | Enumerated types are created using the `createTypeEnum` command, for example
820−--
821−-- >>> printSQL $ createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy" :* Nil)
822−-- CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');
823−createTypeEnum
824− :: (KnownSymbol enum, SOP.All KnownSymbol labels)
825− => Alias enum
826− -- ^ name of the user defined enumerated type
827− -> NP PGlabel labels
828− -- ^ labels of the enumerated type
829− -> Definition schema (Create enum ('Typedef ('PGenum labels)) schema)
830−createTypeEnum enum labels = UnsafeDefinition $
831− "CREATE" <+> "TYPE" <+> renderAlias enum <+> "AS" <+> "ENUM" <+>
832− parenthesized (commaSeparated (renderLabels labels)) <> ";"
833−
834−-- | Enumerated types can also be generated from a Haskell type, for example
835−--
836−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
837−-- >>> instance SOP.Generic Schwarma
838−-- >>> instance SOP.HasDatatypeInfo Schwarma
839−-- >>> printSQL $ createTypeEnumFrom @Schwarma #schwarma
840−-- CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');
841−createTypeEnumFrom
842− :: forall hask enum schema.
843− ( SOP.Generic hask
844− , SOP.All KnownSymbol (LabelsFrom hask)
845− , KnownSymbol enum
846− )
847− => Alias enum
848− -- ^ name of the user defined enumerated type
849− -> Definition schema (Create enum ('Typedef (EnumFrom hask)) schema)
850−createTypeEnumFrom enum = createTypeEnum enum
851− (SOP.hpure label :: NP PGlabel (LabelsFrom hask))
852−
853−-- | `createTypeComposite` creates a composite type. The composite type is
854−-- specified by a list of attribute names and data types.
855−--
856−-- >>> printSQL $ createTypeComposite #complex (float8 `As` #real :* float8 `As` #imaginary :* Nil)
857−-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
858−createTypeComposite
859− :: (KnownSymbol ty, SOP.SListI fields)
860− => Alias ty
861− -- ^ name of the user defined composite type
862− -> NP (Aliased (TypeExpression schema)) fields
863− -- ^ list of attribute names and data types
864− -> Definition schema (Create ty ('Typedef ('PGcomposite fields)) schema)
865−createTypeComposite ty fields = UnsafeDefinition $
866− "CREATE" <+> "TYPE" <+> renderAlias ty <+> "AS" <+> parenthesized
867− (renderCommaSeparated renderField fields) <> ";"
868− where
869− renderField :: Aliased (TypeExpression schema) x -> ByteString
870− renderField (typ `As` field) =
871− renderAlias field <+> renderTypeExpression typ
872−
873−-- | Composite types can also be generated from a Haskell type, for example
874−--
875−-- >>> data Complex = Complex {real :: Maybe Double, imaginary :: Maybe Double} deriving GHC.Generic
876−-- >>> instance SOP.Generic Complex
877−-- >>> instance SOP.HasDatatypeInfo Complex
878−-- >>> printSQL $ createTypeCompositeFrom @Complex #complex
879−-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
880−createTypeCompositeFrom
881− :: forall hask ty schema.
882− ( ZipAliased (FieldNamesFrom hask) (FieldTypesFrom hask)
883− , SOP.All (PGTyped schema) (FieldTypesFrom hask)
884− , KnownSymbol ty
885− )
886− => Alias ty
887− -- ^ name of the user defined composite type
888− -> Definition schema (Create ty ( 'Typedef (CompositeFrom hask)) schema)
889−createTypeCompositeFrom ty = createTypeComposite ty $ zipAs
890− (SOP.hpure Alias :: NP Alias (FieldNamesFrom hask))
891− (SOP.hcpure (SOP.Proxy :: SOP.Proxy (PGTyped schema)) pgtype
892− :: NP (TypeExpression schema) (FieldTypesFrom hask))
893−
894−-- | Drop a type.
895−--
896−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
897−-- >>> instance SOP.Generic Schwarma
898−-- >>> instance SOP.HasDatatypeInfo Schwarma
899−-- >>> printSQL (dropType #schwarma :: Definition '["schwarma" ::: 'Typedef (EnumFrom Schwarma)] '[])
900−-- DROP TYPE "schwarma";
901−dropType
902− :: Has tydef schema ('Typedef ty)
903− => Alias tydef
904− -- ^ name of the user defined type
905− -> Definition schema (Drop tydef schema)
906−dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderAlias tydef <> ";"
907−
908−-- | `ColumnTypeExpression`s are used in `createTable` commands.
909−newtype ColumnTypeExpression (schema :: SchemaType) (ty :: ColumnType)
910− = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }
911− deriving (GHC.Generic,Show,Eq,Ord,NFData)
912−
913−-- | used in `createTable` commands as a column constraint to note that
914−-- @NULL@ may be present in a column
915−nullable
916− :: TypeExpression schema ty
917− -> ColumnTypeExpression schema ('NoDef :=> 'Null ty)
918−nullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NULL"
919−
920−-- | used in `createTable` commands as a column constraint to ensure
921−-- @NULL@ is not present in a column
922−notNullable
923− :: TypeExpression schema ty
924− -> ColumnTypeExpression schema (def :=> 'NotNull ty)
925−notNullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NOT NULL"
926−
927−-- | used in `createTable` commands as a column constraint to give a default
928−default_
929− :: Expression schema '[] 'Ungrouped '[] ty
930− -> ColumnTypeExpression schema ('NoDef :=> ty)
931− -> ColumnTypeExpression schema ('Def :=> ty)
932−default_ x ty = UnsafeColumnTypeExpression $
933− renderColumnTypeExpression ty <+> "DEFAULT" <+> renderExpression x
934−
935−-- | not a true type, but merely a notational convenience for creating
936−-- unique identifier columns with type `PGint2`
937−serial2, smallserial
938− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint2)
939−serial2 = UnsafeColumnTypeExpression "serial2"
940−smallserial = UnsafeColumnTypeExpression "smallserial"
941−-- | not a true type, but merely a notational convenience for creating
942−-- unique identifier columns with type `PGint4`
943−serial4, serial
944− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint4)
945−serial4 = UnsafeColumnTypeExpression "serial4"
946−serial = UnsafeColumnTypeExpression "serial"
947−-- | not a true type, but merely a notational convenience for creating
948−-- unique identifier columns with type `PGint8`
949−serial8, bigserial
950− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint8)
951−serial8 = UnsafeColumnTypeExpression "serial8"
952−bigserial = UnsafeColumnTypeExpression "bigserial"
squeal-postgresql/src/Squeal/PostgreSQL/Definition/Function.hsnew file+238
@@ -0,0 +1,238 @@
1+{-|
2+Module: Squeal.PostgreSQL.Definition.Function
3+Description: Create and drop function and operator definitions
4+Copyright: (c) Eitan Chatav, 2017
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Create and drop function and operator definitions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DerivingStrategies
17+ , FlexibleContexts
18+ , FlexibleInstances
19+ , GADTs
20+ , LambdaCase
21+ , MultiParamTypeClasses
22+ , OverloadedLabels
23+ , OverloadedStrings
24+ , RankNTypes
25+ , ScopedTypeVariables
26+ , TypeApplications
27+ , TypeInType
28+ , TypeOperators
29+ , UndecidableSuperClasses
30+#-}
31+
32+module Squeal.PostgreSQL.Definition.Function
33+ ( createFunction
34+ , createOrReplaceFunction
35+ , createSetFunction
36+ , createOrReplaceSetFunction
37+ , createBinaryOp
38+ , createLeftOp
39+ , createRightOp
40+ , dropFunction
41+ , dropFunctionIfExists
42+ , dropOperator
43+ , dropOperatorIfExists
44+ , FunctionDefinition(..)
45+ , languageSqlExpr
46+ , languageSqlQuery
47+ ) where
48+
49+import Control.DeepSeq
50+import Data.ByteString
51+import GHC.TypeLits
52+
53+import qualified Generics.SOP as SOP
54+import qualified GHC.Generics as GHC
55+
56+import Squeal.PostgreSQL.Alias
57+import Squeal.PostgreSQL.Definition
58+import Squeal.PostgreSQL.Expression
59+import Squeal.PostgreSQL.Expression.Type
60+import Squeal.PostgreSQL.List
61+import Squeal.PostgreSQL.Query
62+import Squeal.PostgreSQL.Render
63+import Squeal.PostgreSQL.Schema
64+
65+-- $setup
66+-- >>> import Squeal.PostgreSQL
67+
68+createFunction
69+ :: ( Has sch schemas schema
70+ , KnownSymbol fun
71+ , SOP.SListI args )
72+ => QualifiedAlias sch fun
73+ -> NP (TypeExpression schemas) args
74+ -> TypeExpression schemas ret
75+ -> FunctionDefinition schemas args ('Returns ret)
76+ -> Definition schemas (Alter sch (Create fun ('Function (args :=> 'Returns ret)) schema) schemas)
77+createFunction fun args ret fundef = UnsafeDefinition $
78+ "CREATE" <+> "FUNCTION" <+> renderSQL fun
79+ <+> parenthesized (renderCommaSeparated renderSQL args)
80+ <+> "RETURNS" <+> renderSQL ret <+> renderSQL fundef <> ";"
81+
82+createOrReplaceFunction
83+ :: ( Has sch schemas schema
84+ , KnownSymbol fun
85+ , SOP.SListI args )
86+ => QualifiedAlias sch fun
87+ -> NP (TypeExpression schemas) args
88+ -> TypeExpression schemas ret
89+ -> FunctionDefinition schemas args ('Returns ret)
90+ -> Definition schemas (Alter sch (CreateOrReplace fun ('Function (args :=> 'Returns ret)) schema) schemas)
91+createOrReplaceFunction fun args ret fundef = UnsafeDefinition $
92+ "CREATE" <+> "OR" <+> "REPLACE" <+> "FUNCTION" <+> renderSQL fun
93+ <+> parenthesized (renderCommaSeparated renderSQL args)
94+ <+> "RETURNS" <+> renderSQL ret <+> renderSQL fundef <> ";"
95+
96+languageSqlExpr
97+ :: Expression '[] '[] 'Ungrouped schemas args '[] ret
98+ -> FunctionDefinition schemas args ('Returns ret)
99+languageSqlExpr expr = UnsafeFunctionDefinition $
100+ "language sql as"
101+ <+> "$$" <+> renderSQL (values_ (expr `as` #ret)) <+> "$$"
102+
103+languageSqlQuery
104+ :: Query '[] '[] schemas args rets
105+ -> FunctionDefinition schemas args ('ReturnsTable rets)
106+languageSqlQuery qry = UnsafeFunctionDefinition $
107+ "language sql as" <+> "$$" <+> renderSQL qry <+> "$$"
108+
109+createSetFunction
110+ :: ( Has sch schemas schema
111+ , KnownSymbol fun
112+ , SOP.SListI args
113+ , SOP.SListI rets )
114+ => QualifiedAlias sch fun
115+ -> NP (TypeExpression schemas) args
116+ -> NP (Aliased (TypeExpression schemas)) rets
117+ -> FunctionDefinition schemas args ('ReturnsTable rets)
118+ -> Definition schemas (Alter sch (Create fun ('Function (args :=> 'ReturnsTable rets)) schema) schemas)
119+createSetFunction fun args rets fundef = UnsafeDefinition $
120+ "CREATE" <+> "FUNCTION" <+> renderSQL fun
121+ <+> parenthesized (renderCommaSeparated renderSQL args)
122+ <+> "RETURNS" <+> "TABLE"
123+ <+> parenthesized (renderCommaSeparated renderRet rets)
124+ <+> renderSQL fundef <> ";"
125+ where
126+ renderRet :: Aliased (TypeExpression s) r -> ByteString
127+ renderRet (ty `As` col) = renderSQL col <+> renderSQL ty
128+
129+createOrReplaceSetFunction
130+ :: ( Has sch schemas schema
131+ , KnownSymbol fun
132+ , SOP.SListI args
133+ , SOP.SListI rets )
134+ => QualifiedAlias sch fun
135+ -> NP (TypeExpression schemas) args
136+ -> NP (Aliased (TypeExpression schemas)) rets
137+ -> FunctionDefinition schemas args ('ReturnsTable rets)
138+ -> Definition schemas (Alter sch (CreateOrReplace fun ('Function (args :=> 'ReturnsTable rets)) schema) schemas)
139+createOrReplaceSetFunction fun args rets fundef = UnsafeDefinition $
140+ "CREATE" <+> "OR" <+> "REPLACE" <+> "FUNCTION" <+> renderSQL fun
141+ <+> parenthesized (renderCommaSeparated renderSQL args)
142+ <+> "RETURNS" <+> "TABLE"
143+ <+> parenthesized (renderCommaSeparated renderRet rets)
144+ <+> renderSQL fundef <> ";"
145+ where
146+ renderRet :: Aliased (TypeExpression s) r -> ByteString
147+ renderRet (ty `As` col) = renderSQL col <+> renderSQL ty
148+
149+createBinaryOp
150+ :: forall op fun sch schemas schema x y z.
151+ ( Has sch schemas schema
152+ , Has fun schema ('Function ('[x,y] :=> 'Returns z))
153+ , KnownSymbol op )
154+ => QualifiedAlias sch fun
155+ -> TypeExpression schemas x
156+ -> TypeExpression schemas y
157+ -> Definition schemas
158+ (Alter sch (Create op ('Operator ('BinaryOp x y z)) schema) schemas)
159+createBinaryOp fun x y = UnsafeDefinition $
160+ "CREATE" <+> "OPERATOR" <+> renderSymbol @op
161+ <+> parenthesized (commaSeparated opdef)
162+ where
163+ opdef =
164+ [ "FUNCTION" <+> "=" <+> renderSQL fun
165+ , "LEFTARG" <+> "=" <+> renderSQL x
166+ , "RIGHTARG" <+> "=" <+> renderSQL y ]
167+
168+createLeftOp
169+ :: forall op fun sch schemas schema x y.
170+ ( Has sch schemas schema
171+ , Has fun schema ('Function ('[x] :=> 'Returns y))
172+ , KnownSymbol op )
173+ => QualifiedAlias sch fun
174+ -> TypeExpression schemas x
175+ -> Definition schemas
176+ (Alter sch (Create op ('Operator ('LeftOp x y)) schema) schemas)
177+createLeftOp fun x = UnsafeDefinition $
178+ "CREATE" <+> "OPERATOR" <+> renderSymbol @op
179+ <+> parenthesized (commaSeparated opdef)
180+ where
181+ opdef =
182+ [ "FUNCTION" <+> "=" <+> renderSQL fun
183+ , "RIGHTARG" <+> "=" <+> renderSQL x ]
184+
185+createRightOp
186+ :: forall op fun sch schemas schema x y.
187+ ( Has sch schemas schema
188+ , Has fun schema ('Function ('[x] :=> 'Returns y))
189+ , KnownSymbol op )
190+ => QualifiedAlias sch fun
191+ -> TypeExpression schemas x
192+ -> Definition schemas
193+ (Alter sch (Create op ('Operator ('RightOp x y)) schema) schemas)
194+createRightOp fun x = UnsafeDefinition $
195+ "CREATE" <+> "OPERATOR" <+> renderSymbol @op
196+ <+> parenthesized (commaSeparated opdef)
197+ where
198+ opdef =
199+ [ "FUNCTION" <+> "=" <+> renderSQL fun
200+ , "LEFTARG" <+> "=" <+> renderSQL x ]
201+
202+dropFunction
203+ :: (Has sch schemas schema, KnownSymbol fun)
204+ => QualifiedAlias sch fun
205+ -- ^ name of the user defined function
206+ -> Definition schemas (Alter sch (DropSchemum fun 'Function schema) schemas)
207+dropFunction fun = UnsafeDefinition $
208+ "DROP" <+> "FUNCTION" <+> renderSQL fun <> ";"
209+
210+dropFunctionIfExists
211+ :: (Has sch schemas schema, KnownSymbol fun)
212+ => QualifiedAlias sch fun
213+ -- ^ name of the user defined function
214+ -> Definition schemas (Alter sch (DropSchemumIfExists fun 'Function schema) schemas)
215+dropFunctionIfExists fun = UnsafeDefinition $
216+ "DROP FUNCTION IF EXISTS" <+> renderSQL fun <> ";"
217+
218+dropOperator
219+ :: (Has sch schemas schema, KnownSymbol op)
220+ => QualifiedAlias sch op
221+ -- ^ name of the user defined operator
222+ -> Definition schemas (Alter sch (DropSchemum op 'Operator schema) schemas)
223+dropOperator op = UnsafeDefinition $
224+ "DROP" <+> "OPERATOR" <+> renderSQL op <> ";"
225+
226+dropOperatorIfExists
227+ :: (Has sch schemas schema, KnownSymbol op)
228+ => QualifiedAlias sch op
229+ -- ^ name of the user defined operator
230+ -> Definition schemas (Alter sch (DropSchemumIfExists op 'Operator schema) schemas)
231+dropOperatorIfExists op = UnsafeDefinition $
232+ "DROP OPERATOR IF EXISTS" <+> renderSQL op <> ";"
233+
234+newtype FunctionDefinition schemas args ret = UnsafeFunctionDefinition
235+ { renderFunctionDefinition :: ByteString }
236+ deriving (Eq,Show,GHC.Generic,NFData)
237+instance RenderSQL (FunctionDefinition schemas args ret) where
238+ renderSQL = renderFunctionDefinition
squeal-postgresql/src/Squeal/PostgreSQL/Definition/Index.hsnew file+159
@@ -0,0 +1,159 @@
1+{-|
2+Module: Squeal.PostgreSQL.Definition.Index
3+Description: Create and drop index definitions
4+Copyright: (c) Eitan Chatav, 2017
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Create and drop index definitions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DerivingStrategies
17+ , FlexibleContexts
18+ , FlexibleInstances
19+ , GADTs
20+ , LambdaCase
21+ , MultiParamTypeClasses
22+ , OverloadedLabels
23+ , OverloadedStrings
24+ , RankNTypes
25+ , ScopedTypeVariables
26+ , TypeApplications
27+ , TypeInType
28+ , TypeOperators
29+ , UndecidableSuperClasses
30+#-}
31+
32+module Squeal.PostgreSQL.Definition.Index
33+ ( createIndex
34+ , createIndexIfNotExists
35+ , dropIndex
36+ , dropIndexIfExists
37+ , IndexMethod (..)
38+ , btree
39+ , hash
40+ , gist
41+ , spgist
42+ , gin
43+ , brin
44+ ) where
45+
46+import Data.ByteString
47+import GHC.TypeLits
48+
49+import qualified GHC.Generics as GHC
50+
51+import Squeal.PostgreSQL.Alias
52+import Squeal.PostgreSQL.Definition
53+import Squeal.PostgreSQL.Expression.Sort
54+import Squeal.PostgreSQL.Render
55+import Squeal.PostgreSQL.Schema
56+
57+-- $setup
58+-- >>> import Squeal.PostgreSQL
59+
60+{- |
61+>>> :{
62+type Table = '[] :=>
63+ '[ "a" ::: 'NoDef :=> 'Null 'PGint4
64+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]
65+:}
66+
67+>>> :{
68+let
69+ setup :: Definition (Public '[]) (Public '["tab" ::: 'Table Table, "ix" ::: 'Index 'Btree])
70+ setup =
71+ createTable #tab (nullable int `as` #a :* nullable real `as` #b) Nil >>>
72+ createIndex #ix #tab btree [#a & AscNullsFirst, #b & AscNullsLast]
73+in printSQL setup
74+:}
75+CREATE TABLE "tab" ("a" int NULL, "b" real NULL);
76+CREATE INDEX "ix" ON "tab" USING btree (("a") ASC NULLS FIRST, ("b") ASC NULLS LAST);
77+-}
78+createIndex
79+ :: (Has sch schemas schema, Has tab schema ('Table table), KnownSymbol ix)
80+ => Alias ix
81+ -> QualifiedAlias sch tab
82+ -> IndexMethod method
83+ -> [SortExpression '[] '[] 'Ungrouped schemas '[] '[tab ::: TableToRow table]]
84+ -> Definition schemas (Alter sch (Create ix ('Index method) schema) schemas)
85+createIndex ix tab method cols = UnsafeDefinition $
86+ "CREATE" <+> "INDEX" <+> renderSQL ix <+> "ON" <+> renderSQL tab
87+ <+> "USING" <+> renderSQL method
88+ <+> parenthesized (commaSeparated (renderIndex <$> cols))
89+ <> ";"
90+ where
91+ renderIndex = \case
92+ Asc expression -> parenthesized (renderSQL expression) <+> "ASC"
93+ Desc expression -> parenthesized (renderSQL expression) <+> "DESC"
94+ AscNullsFirst expression -> parenthesized (renderSQL expression)
95+ <+> "ASC NULLS FIRST"
96+ DescNullsFirst expression -> parenthesized (renderSQL expression)
97+ <+> "DESC NULLS FIRST"
98+ AscNullsLast expression -> parenthesized (renderSQL expression)
99+ <+> "ASC NULLS LAST"
100+ DescNullsLast expression -> parenthesized (renderSQL expression)
101+ <+> "DESC NULLS LAST"
102+
103+createIndexIfNotExists
104+ :: (Has sch schemas schema, Has tab schema ('Table table), KnownSymbol ix)
105+ => Alias ix
106+ -> QualifiedAlias sch tab
107+ -> IndexMethod method
108+ -> [SortExpression '[] '[] 'Ungrouped schemas '[] '[tab ::: TableToRow table]]
109+ -> Definition schemas (Alter sch (CreateIfNotExists ix ('Index method) schema) schemas)
110+createIndexIfNotExists ix tab method cols = UnsafeDefinition $
111+ "CREATE INDEX IF NOT EXISTS" <+> renderSQL ix <+> "ON" <+> renderSQL tab
112+ <+> "USING" <+> renderSQL method
113+ <+> parenthesized (commaSeparated (renderIndex <$> cols))
114+ <> ";"
115+ where
116+ renderIndex = \case
117+ Asc expression -> parenthesized (renderSQL expression) <+> "ASC"
118+ Desc expression -> parenthesized (renderSQL expression) <+> "DESC"
119+ AscNullsFirst expression -> parenthesized (renderSQL expression)
120+ <+> "ASC NULLS FIRST"
121+ DescNullsFirst expression -> parenthesized (renderSQL expression)
122+ <+> "DESC NULLS FIRST"
123+ AscNullsLast expression -> parenthesized (renderSQL expression)
124+ <+> "ASC NULLS LAST"
125+ DescNullsLast expression -> parenthesized (renderSQL expression)
126+ <+> "DESC NULLS LAST"
127+
128+newtype IndexMethod ty = UnsafeIndexMethod {renderIndexMethod :: ByteString}
129+ deriving stock (Eq, Ord, Show, GHC.Generic)
130+instance RenderSQL (IndexMethod ty) where renderSQL = renderIndexMethod
131+btree :: IndexMethod 'Btree
132+btree = UnsafeIndexMethod "btree"
133+hash :: IndexMethod 'Hash
134+hash = UnsafeIndexMethod "hash"
135+gist :: IndexMethod 'Gist
136+gist = UnsafeIndexMethod "gist"
137+spgist :: IndexMethod 'Spgist
138+spgist = UnsafeIndexMethod "spgist"
139+gin :: IndexMethod 'Gin
140+gin = UnsafeIndexMethod "gin"
141+brin :: IndexMethod 'Brin
142+brin = UnsafeIndexMethod "brin"
143+
144+-- |
145+-- >>> printSQL (dropIndex #ix :: Definition (Public '["ix" ::: 'Index 'Btree]) (Public '[]))
146+-- DROP INDEX "ix";
147+dropIndex
148+ :: (Has sch schemas schema, KnownSymbol ix)
149+ => QualifiedAlias sch ix
150+ -- ^ name of the user defined index
151+ -> Definition schemas (Alter sch (DropSchemum ix 'Index schema) schemas)
152+dropIndex ix = UnsafeDefinition $ "DROP" <+> "INDEX" <+> renderSQL ix <> ";"
153+
154+dropIndexIfExists
155+ :: (Has sch schemas schema, KnownSymbol ix)
156+ => QualifiedAlias sch ix
157+ -- ^ name of the user defined index
158+ -> Definition schemas (Alter sch (DropSchemumIfExists ix 'Index schema) schemas)
159+dropIndexIfExists ix = UnsafeDefinition $ "DROP INDEX IF EXISTS" <+> renderSQL ix <> ";"
squeal-postgresql/src/Squeal/PostgreSQL/Definition/Schema.hsnew file+96
@@ -0,0 +1,96 @@
1+{-|
2+Module: Squeal.PostgreSQL.Definition.Schema
3+Description: Create and drop schema definitions
4+Copyright: (c) Eitan Chatav, 2017
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Create and drop schema definitions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DerivingStrategies
17+ , FlexibleContexts
18+ , FlexibleInstances
19+ , GADTs
20+ , LambdaCase
21+ , MultiParamTypeClasses
22+ , OverloadedLabels
23+ , OverloadedStrings
24+ , RankNTypes
25+ , ScopedTypeVariables
26+ , TypeApplications
27+ , TypeInType
28+ , TypeOperators
29+ , UndecidableSuperClasses
30+#-}
31+
32+module Squeal.PostgreSQL.Definition.Schema
33+ ( createSchema
34+ , createSchemaIfNotExists
35+ , dropSchema
36+ , dropSchemaIfExists
37+ ) where
38+
39+import GHC.TypeLits
40+
41+import Squeal.PostgreSQL.Alias
42+import Squeal.PostgreSQL.Definition
43+import Squeal.PostgreSQL.Render
44+import Squeal.PostgreSQL.Schema
45+
46+-- $setup
47+-- >>> import Squeal.PostgreSQL
48+
49+{- |
50+`createSchema` enters a new schema into the current database.
51+The schema name must be distinct from the name of any existing schema
52+in the current database.
53+
54+A schema is essentially a namespace: it contains named objects
55+(tables, data types, functions, and operators) whose names
56+can duplicate those of other objects existing in other schemas.
57+Named objects are accessed by `QualifiedAlias`es with the schema
58+name as a prefix.
59+-}
60+createSchema
61+ :: KnownSymbol sch
62+ => Alias sch
63+ -> Definition schemas (Create sch '[] schemas)
64+createSchema sch = UnsafeDefinition $
65+ "CREATE" <+> "SCHEMA" <+> renderSQL sch <> ";"
66+
67+{- | Idempotent version of `createSchema`. -}
68+createSchemaIfNotExists
69+ :: (KnownSymbol sch, Has sch schemas schema)
70+ => Alias sch
71+ -> Definition schemas (CreateIfNotExists sch '[] schemas)
72+createSchemaIfNotExists sch = UnsafeDefinition $
73+ "CREATE" <+> "SCHEMA" <+> "IF" <+> "NOT" <+> "EXISTS"
74+ <+> renderSQL sch <> ";"
75+
76+-- | >>> :{
77+-- let
78+-- definition :: Definition '["muh_schema" ::: schema, "public" ::: public] '["public" ::: public]
79+-- definition = dropSchema #muh_schema
80+-- :}
81+--
82+-- >>> printSQL definition
83+-- DROP SCHEMA "muh_schema";
84+dropSchema
85+ :: KnownSymbol sch
86+ => Alias sch
87+ -- ^ user defined schema
88+ -> Definition schemas (Drop sch schemas)
89+dropSchema sch = UnsafeDefinition $ "DROP SCHEMA" <+> renderSQL sch <> ";"
90+
91+dropSchemaIfExists
92+ :: KnownSymbol sch
93+ => Alias sch
94+ -- ^ user defined schema
95+ -> Definition schemas (DropIfExists sch schemas)
96+dropSchemaIfExists sch = UnsafeDefinition $ "DROP SCHEMA" <+> renderSQL sch <> ";"
squeal-postgresql/src/Squeal/PostgreSQL/Definition/Table.hsnew file+500
@@ -0,0 +1,500 @@
1+{-|
2+Module: Squeal.PostgreSQL.Definition.Table
3+Description: Create, drop and alter table definitions
4+Copyright: (c) Eitan Chatav, 2017
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Create, drop and alter table definitions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DerivingStrategies
17+ , FlexibleContexts
18+ , FlexibleInstances
19+ , GADTs
20+ , LambdaCase
21+ , MultiParamTypeClasses
22+ , OverloadedLabels
23+ , OverloadedStrings
24+ , RankNTypes
25+ , ScopedTypeVariables
26+ , TypeApplications
27+ , TypeInType
28+ , TypeOperators
29+ , UndecidableSuperClasses
30+#-}
31+
32+module Squeal.PostgreSQL.Definition.Table
33+ ( createTable
34+ , createTableIfNotExists
35+ , dropTable
36+ , dropTableIfExists
37+ , alterTable
38+ , alterTableIfExists
39+ , alterTableRename
40+ , alterTableIfExistsRename
41+ , AlterTable (..)
42+ , addConstraint
43+ , dropConstraint
44+ , AddColumn (..)
45+ , dropColumn
46+ , renameColumn
47+ , alterColumn
48+ , AlterColumn (..)
49+ , setDefault
50+ , dropDefault
51+ , setNotNull
52+ , dropNotNull
53+ , alterType
54+ ) where
55+
56+import Control.DeepSeq
57+import Data.ByteString
58+import GHC.TypeLits
59+
60+import qualified Generics.SOP as SOP
61+import qualified GHC.Generics as GHC
62+
63+import Squeal.PostgreSQL.Alias
64+import Squeal.PostgreSQL.Definition
65+import Squeal.PostgreSQL.Definition.Table.Constraint
66+import Squeal.PostgreSQL.Expression
67+import Squeal.PostgreSQL.Expression.Type
68+import Squeal.PostgreSQL.List
69+import Squeal.PostgreSQL.Render
70+import Squeal.PostgreSQL.Schema
71+
72+-- $setup
73+-- >>> import Squeal.PostgreSQL
74+
75+{- | `createTable` adds a table to the schema.
76+
77+>>> :set -XOverloadedLabels
78+>>> :{
79+type Table = '[] :=>
80+ '[ "a" ::: 'NoDef :=> 'Null 'PGint4
81+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]
82+:}
83+
84+>>> :{
85+let
86+ setup :: Definition (Public '[]) (Public '["tab" ::: 'Table Table])
87+ setup = createTable #tab
88+ (nullable int `as` #a :* nullable real `as` #b) Nil
89+in printSQL setup
90+:}
91+CREATE TABLE "tab" ("a" int NULL, "b" real NULL);
92+-}
93+createTable
94+ :: ( KnownSymbol sch
95+ , KnownSymbol tab
96+ , columns ~ (col ': cols)
97+ , SOP.SListI columns
98+ , SOP.SListI constraints
99+ , Has sch schemas0 schema0
100+ , schemas1 ~ Alter sch (Create tab ('Table (constraints :=> columns)) schema0) schemas0 )
101+ => QualifiedAlias sch tab -- ^ the name of the table to add
102+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns
103+ -- ^ the names and datatype of each column
104+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints
105+ -- ^ constraints that must hold for the table
106+ -> Definition schemas0 schemas1
107+createTable tab columns constraints = UnsafeDefinition $
108+ "CREATE TABLE" <+> renderCreation tab columns constraints
109+
110+{-| `createTableIfNotExists` creates a table if it doesn't exist, but does not add it to the schema.
111+Instead, the schema already has the table so if the table did not yet exist, the schema was wrong.
112+`createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in
113+the `Category` of `Definition`s.
114+
115+>>> :set -XOverloadedLabels -XTypeApplications
116+>>> :{
117+type Table = '[] :=>
118+ '[ "a" ::: 'NoDef :=> 'Null 'PGint4
119+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]
120+:}
121+
122+>>> type Schemas = Public '["tab" ::: 'Table Table]
123+
124+>>> :{
125+let
126+ setup :: Definition Schemas Schemas
127+ setup = createTableIfNotExists #tab
128+ (nullable int `as` #a :* nullable real `as` #b) Nil
129+in printSQL setup
130+:}
131+CREATE TABLE IF NOT EXISTS "tab" ("a" int NULL, "b" real NULL);
132+-}
133+createTableIfNotExists
134+ :: ( KnownSymbol sch
135+ , KnownSymbol tab
136+ , columns ~ (col ': cols)
137+ , SOP.SListI columns
138+ , SOP.SListI constraints
139+ , Has sch schemas0 schema0
140+ , schemas1 ~ Alter sch (CreateIfNotExists tab ('Table (constraints :=> columns)) schema0) schemas0 )
141+ => QualifiedAlias sch tab -- ^ the name of the table to add
142+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns
143+ -- ^ the names and datatype of each column
144+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints
145+ -- ^ constraints that must hold for the table
146+ -> Definition schemas0 schemas1
147+createTableIfNotExists tab columns constraints = UnsafeDefinition $
148+ "CREATE TABLE IF NOT EXISTS"
149+ <+> renderCreation tab columns constraints
150+
151+-- helper function for `createTable` and `createTableIfNotExists`
152+renderCreation
153+ :: ( KnownSymbol sch
154+ , KnownSymbol tab
155+ , SOP.SListI columns
156+ , SOP.SListI constraints )
157+ => QualifiedAlias sch tab -- ^ the name of the table to add
158+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns
159+ -- ^ the names and datatype of each column
160+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints
161+ -- ^ constraints that must hold for the table
162+ -> ByteString
163+renderCreation tab columns constraints = renderSQL tab
164+ <+> parenthesized
165+ ( renderCommaSeparated renderColumnDef columns
166+ <> ( case constraints of
167+ Nil -> ""
168+ _ -> ", " <>
169+ renderCommaSeparated renderConstraint constraints ) )
170+ <> ";"
171+ where
172+ renderColumnDef :: Aliased (ColumnTypeExpression schemas) x -> ByteString
173+ renderColumnDef (ty `As` column) =
174+ renderSQL column <+> renderColumnTypeExpression ty
175+ renderConstraint
176+ :: Aliased (TableConstraintExpression sch tab schemas) constraint
177+ -> ByteString
178+ renderConstraint (constraint `As` alias) =
179+ "CONSTRAINT" <+> renderSQL alias <+> renderSQL constraint
180+
181+-- | `dropTable` removes a table from the schema.
182+--
183+-- >>> :{
184+-- let
185+-- definition :: Definition '["public" ::: '["muh_table" ::: 'Table t]] (Public '[])
186+-- definition = dropTable #muh_table
187+-- :}
188+--
189+-- >>> printSQL definition
190+-- DROP TABLE "muh_table";
191+dropTable
192+ :: ( Has sch schemas schema
193+ , KnownSymbol tab )
194+ => QualifiedAlias sch tab -- ^ table to remove
195+ -> Definition schemas (Alter sch (DropSchemum tab 'Table schema) schemas)
196+dropTable tab = UnsafeDefinition $ "DROP TABLE" <+> renderSQL tab <> ";"
197+
198+dropTableIfExists
199+ :: ( Has sch schemas schema
200+ , KnownSymbol tab)
201+ => QualifiedAlias sch tab -- ^ table to remove
202+ -> Definition schemas (Alter sch (DropSchemumIfExists tab 'Table schema) schemas)
203+dropTableIfExists tab = UnsafeDefinition $ "DROP TABLE IF EXISTS" <+> renderSQL tab <> ";"
204+
205+-- | `alterTable` changes the definition of a table from the schema.
206+alterTable
207+ :: (Has sch schemas schema, KnownSymbol tab)
208+ => QualifiedAlias sch tab -- ^ table to alter
209+ -> AlterTable sch tab schemas table -- ^ alteration to perform
210+ -> Definition schemas (Alter sch (Alter tab ('Table table) schema) schemas)
211+alterTable tab alteration = UnsafeDefinition $
212+ "ALTER TABLE"
213+ <+> renderSQL tab
214+ <+> renderAlterTable alteration
215+ <> ";"
216+
217+-- | `alterTable` changes the definition of a table from the schema.
218+alterTableIfExists
219+ :: (Has sch schemas schema, KnownSymbol tab)
220+ => QualifiedAlias sch tab -- ^ table to alter
221+ -> AlterTable sch tab schemas table -- ^ alteration to perform
222+ -> Definition schemas (Alter sch (AlterIfExists tab ('Table table) schema) schemas)
223+alterTableIfExists tab alteration = UnsafeDefinition $
224+ "ALTER TABLE IF EXISTS"
225+ <+> renderSQL tab
226+ <+> renderAlterTable alteration
227+ <> ";"
228+
229+-- | `alterTableRename` changes the name of a table from the schema.
230+--
231+-- >>> printSQL $ alterTableRename #foo #bar
232+-- ALTER TABLE "foo" RENAME TO "bar";
233+alterTableRename
234+ :: (KnownSymbol tab0, KnownSymbol tab1)
235+ => Alias tab0 -- ^ table to rename
236+ -> Alias tab1 -- ^ what to rename it
237+ -> Definition schema (Rename tab0 tab1 schema)
238+alterTableRename tab0 tab1 = UnsafeDefinition $
239+ "ALTER TABLE" <+> renderSQL tab0
240+ <+> "RENAME TO" <+> renderSQL tab1 <> ";"
241+
242+alterTableIfExistsRename
243+ :: (KnownSymbol tab0, KnownSymbol tab1)
244+ => Alias tab0 -- ^ table to rename
245+ -> Alias tab1 -- ^ what to rename it
246+ -> Definition schema (RenameIfExists tab0 tab1 schema)
247+alterTableIfExistsRename tab0 tab1 = UnsafeDefinition $
248+ "ALTER TABLE IF EXISTS" <+> renderSQL tab0
249+ <+> "RENAME TO" <+> renderSQL tab1 <> ";"
250+
251+-- | An `AlterTable` describes the alteration to perform on the columns
252+-- of a table.
253+newtype AlterTable
254+ (sch :: Symbol)
255+ (tab :: Symbol)
256+ (schemas :: SchemasType)
257+ (table :: TableType) =
258+ UnsafeAlterTable {renderAlterTable :: ByteString}
259+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
260+
261+-- | An `addConstraint` adds a table constraint.
262+--
263+-- >>> :{
264+-- let
265+-- definition :: Definition
266+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
267+-- '["public" ::: '["tab" ::: 'Table ('["positive" ::: 'Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
268+-- definition = alterTable #tab (addConstraint #positive (check #col (#col .> 0)))
269+-- in printSQL definition
270+-- :}
271+-- ALTER TABLE "tab" ADD CONSTRAINT "positive" CHECK (("col" > 0));
272+addConstraint
273+ :: ( KnownSymbol alias
274+ , Has sch schemas schema
275+ , Has tab schema ('Table table0)
276+ , table0 ~ (constraints :=> columns)
277+ , table1 ~ (Create alias constraint constraints :=> columns) )
278+ => Alias alias
279+ -> TableConstraintExpression sch tab schemas constraint
280+ -- ^ constraint to add
281+ -> AlterTable sch tab schemas table1
282+addConstraint alias constraint = UnsafeAlterTable $
283+ "ADD" <+> "CONSTRAINT" <+> renderSQL alias
284+ <+> renderSQL constraint
285+
286+-- | A `dropConstraint` drops a table constraint.
287+--
288+-- >>> :{
289+-- let
290+-- definition :: Definition
291+-- '["public" ::: '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
292+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
293+-- definition = alterTable #tab (dropConstraint #positive)
294+-- in printSQL definition
295+-- :}
296+-- ALTER TABLE "tab" DROP CONSTRAINT "positive";
297+dropConstraint
298+ :: ( KnownSymbol constraint
299+ , Has sch schemas schema
300+ , Has tab schema ('Table table0)
301+ , table0 ~ (constraints :=> columns)
302+ , table1 ~ (Drop constraint constraints :=> columns) )
303+ => Alias constraint
304+ -- ^ constraint to drop
305+ -> AlterTable sch tab schemas table1
306+dropConstraint constraint = UnsafeAlterTable $
307+ "DROP" <+> "CONSTRAINT" <+> renderSQL constraint
308+
309+-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.
310+class AddColumn ty where
311+ -- | `addColumn` adds a new column, initially filled with whatever
312+ -- default value is given or with @NULL@.
313+ --
314+ -- >>> :{
315+ -- let
316+ -- definition :: Definition
317+ -- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]
318+ -- '["public" ::: '["tab" ::: 'Table ('[] :=>
319+ -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
320+ -- , "col2" ::: 'Def :=> 'Null 'PGtext ])]]
321+ -- definition = alterTable #tab (addColumn #col2 (text & nullable & default_ "foo"))
322+ -- in printSQL definition
323+ -- :}
324+ -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL DEFAULT E'foo';
325+ --
326+ -- >>> :{
327+ -- let
328+ -- definition :: Definition
329+ -- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]
330+ -- '["public" ::: '["tab" ::: 'Table ('[] :=>
331+ -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
332+ -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]]
333+ -- definition = alterTable #tab (addColumn #col2 (text & nullable))
334+ -- in printSQL definition
335+ -- :}
336+ -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL;
337+ addColumn
338+ :: ( KnownSymbol column
339+ , Has sch schemas schema
340+ , Has tab schema ('Table table0)
341+ , table0 ~ (constraints :=> columns) )
342+ => Alias column -- ^ column to add
343+ -> ColumnTypeExpression schemas ty -- ^ type of the new column
344+ -> AlterTable sch tab schemas (constraints :=> Create column ty columns)
345+ addColumn column ty = UnsafeAlterTable $
346+ "ADD COLUMN" <+> renderSQL column <+> renderColumnTypeExpression ty
347+instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)
348+instance {-# OVERLAPPABLE #-} AddColumn ('NoDef :=> 'Null ty)
349+
350+-- | A `dropColumn` removes a column. Whatever data was in the column
351+-- disappears. Table constraints involving the column are dropped, too.
352+-- However, if the column is referenced by a foreign key constraint of
353+-- another table, PostgreSQL will not silently drop that constraint.
354+--
355+-- >>> :{
356+-- let
357+-- definition :: Definition
358+-- '["public" ::: '["tab" ::: 'Table ('[] :=>
359+-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
360+-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]]
361+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]
362+-- definition = alterTable #tab (dropColumn #col2)
363+-- in printSQL definition
364+-- :}
365+-- ALTER TABLE "tab" DROP COLUMN "col2";
366+dropColumn
367+ :: ( KnownSymbol column
368+ , Has sch schemas schema
369+ , Has tab schema ('Table table0)
370+ , table0 ~ (constraints :=> columns)
371+ , table1 ~ (constraints :=> Drop column columns) )
372+ => Alias column -- ^ column to remove
373+ -> AlterTable sch tab schemas table1
374+dropColumn column = UnsafeAlterTable $
375+ "DROP COLUMN" <+> renderSQL column
376+
377+-- | A `renameColumn` renames a column.
378+--
379+-- >>> :{
380+-- let
381+-- definition :: Definition
382+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4])]]
383+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4])]]
384+-- definition = alterTable #tab (renameColumn #foo #bar)
385+-- in printSQL definition
386+-- :}
387+-- ALTER TABLE "tab" RENAME COLUMN "foo" TO "bar";
388+renameColumn
389+ :: ( KnownSymbol column0
390+ , KnownSymbol column1
391+ , Has sch schemas schema
392+ , Has tab schema ('Table table0)
393+ , table0 ~ (constraints :=> columns)
394+ , table1 ~ (constraints :=> Rename column0 column1 columns) )
395+ => Alias column0 -- ^ column to rename
396+ -> Alias column1 -- ^ what to rename the column
397+ -> AlterTable sch tab schemas table1
398+renameColumn column0 column1 = UnsafeAlterTable $
399+ "RENAME COLUMN" <+> renderSQL column0 <+> "TO" <+> renderSQL column1
400+
401+-- | An `alterColumn` alters a single column.
402+alterColumn
403+ :: ( KnownSymbol column
404+ , Has sch schemas schema
405+ , Has tab schema ('Table table0)
406+ , table0 ~ (constraints :=> columns)
407+ , Has column columns ty0
408+ , table1 ~ (constraints :=> Alter column ty1 columns))
409+ => Alias column -- ^ column to alter
410+ -> AlterColumn schemas ty0 ty1 -- ^ alteration to perform
411+ -> AlterTable sch tab schemas table1
412+alterColumn column alteration = UnsafeAlterTable $
413+ "ALTER COLUMN" <+> renderSQL column <+> renderAlterColumn alteration
414+
415+-- | An `AlterColumn` describes the alteration to perform on a single column.
416+newtype AlterColumn (schemas :: SchemasType) (ty0 :: ColumnType) (ty1 :: ColumnType) =
417+ UnsafeAlterColumn {renderAlterColumn :: ByteString}
418+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
419+
420+-- | A `setDefault` sets a new default for a column. Note that this doesn't
421+-- affect any existing rows in the table, it just changes the default for
422+-- future insert and update commands.
423+--
424+-- >>> :{
425+-- let
426+-- definition :: Definition
427+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
428+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]]
429+-- definition = alterTable #tab (alterColumn #col (setDefault 5))
430+-- in printSQL definition
431+-- :}
432+-- ALTER TABLE "tab" ALTER COLUMN "col" SET DEFAULT 5;
433+setDefault
434+ :: Expression '[] '[] 'Ungrouped schemas '[] '[] ty -- ^ default value to set
435+ -> AlterColumn schemas (constraint :=> ty) ('Def :=> ty)
436+setDefault expression = UnsafeAlterColumn $
437+ "SET DEFAULT" <+> renderExpression expression
438+
439+-- | A `dropDefault` removes any default value for a column.
440+--
441+-- >>> :{
442+-- let
443+-- definition :: Definition
444+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]]
445+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
446+-- definition = alterTable #tab (alterColumn #col dropDefault)
447+-- in printSQL definition
448+-- :}
449+-- ALTER TABLE "tab" ALTER COLUMN "col" DROP DEFAULT;
450+dropDefault :: AlterColumn schemas ('Def :=> ty) ('NoDef :=> ty)
451+dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"
452+
453+-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.
454+-- The constraint will be checked immediately, so the table data must satisfy
455+-- the constraint before it can be added.
456+--
457+-- >>> :{
458+-- let
459+-- definition :: Definition
460+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
461+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
462+-- definition = alterTable #tab (alterColumn #col setNotNull)
463+-- in printSQL definition
464+-- :}
465+-- ALTER TABLE "tab" ALTER COLUMN "col" SET NOT NULL;
466+setNotNull
467+ :: AlterColumn schemas (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)
468+setNotNull = UnsafeAlterColumn $ "SET NOT NULL"
469+
470+-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.
471+--
472+-- >>> :{
473+-- let
474+-- definition :: Definition
475+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
476+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
477+-- definition = alterTable #tab (alterColumn #col dropNotNull)
478+-- in printSQL definition
479+-- :}
480+-- ALTER TABLE "tab" ALTER COLUMN "col" DROP NOT NULL;
481+dropNotNull
482+ :: AlterColumn schemas (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)
483+dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"
484+
485+-- | An `alterType` converts a column to a different data type.
486+-- This will succeed only if each existing entry in the column can be
487+-- converted to the new type by an implicit cast.
488+--
489+-- >>> :{
490+-- let
491+-- definition :: Definition
492+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
493+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]]
494+-- definition =
495+-- alterTable #tab (alterColumn #col (alterType (numeric & notNullable)))
496+-- in printSQL definition
497+-- :}
498+-- ALTER TABLE "tab" ALTER COLUMN "col" TYPE numeric NOT NULL;
499+alterType :: ColumnTypeExpression schemas ty -> AlterColumn schemas ty0 ty
500+alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty
squeal-postgresql/src/Squeal/PostgreSQL/Definition/Table/Constraint.hsnew file+339
@@ -0,0 +1,339 @@
1+{-|
2+Module: Squeal.PostgreSQL.Definition.Table.Constraint
3+Description: Table constraint expressions
4+Copyright: (c) Eitan Chatav, 2017
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Table constraint expressions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DerivingStrategies
17+ , FlexibleContexts
18+ , FlexibleInstances
19+ , GADTs
20+ , LambdaCase
21+ , MultiParamTypeClasses
22+ , OverloadedLabels
23+ , OverloadedStrings
24+ , RankNTypes
25+ , ScopedTypeVariables
26+ , TypeApplications
27+ , TypeInType
28+ , TypeOperators
29+ , UndecidableSuperClasses
30+#-}
31+
32+module Squeal.PostgreSQL.Definition.Table.Constraint
33+ ( TableConstraintExpression (..)
34+ , check
35+ , unique
36+ , primaryKey
37+ , foreignKey
38+ , ForeignKeyed
39+ , OnDeleteClause (..)
40+ , OnUpdateClause (..)
41+ ) where
42+
43+import Control.DeepSeq
44+import Data.ByteString
45+import GHC.TypeLits
46+
47+import qualified Generics.SOP as SOP
48+import qualified GHC.Generics as GHC
49+
50+import Squeal.PostgreSQL.Alias
51+import Squeal.PostgreSQL.Expression.Logic
52+import Squeal.PostgreSQL.List
53+import Squeal.PostgreSQL.Render
54+import Squeal.PostgreSQL.Schema
55+
56+-- $setup
57+-- >>> import Squeal.PostgreSQL
58+
59+-- | Data types are a way to limit the kind of data that can be stored in a
60+-- table. For many applications, however, the constraint they provide is
61+-- too coarse. For example, a column containing a product price should
62+-- probably only accept positive values. But there is no standard data type
63+-- that accepts only positive numbers. Another issue is that you might want
64+-- to constrain column data with respect to other columns or rows.
65+-- For example, in a table containing product information,
66+-- there should be only one row for each product number.
67+-- `TableConstraint`s give you as much control over the data in your tables
68+-- as you wish. If a user attempts to store data in a column that would
69+-- violate a constraint, an error is raised. This applies
70+-- even if the value came from the default value definition.
71+newtype TableConstraintExpression
72+ (sch :: Symbol)
73+ (tab :: Symbol)
74+ (schemas :: SchemasType)
75+ (constraint :: TableConstraint)
76+ = UnsafeTableConstraintExpression
77+ { renderTableConstraintExpression :: ByteString }
78+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
79+instance RenderSQL
80+ (TableConstraintExpression sch tab schemas constraint) where
81+ renderSQL = renderTableConstraintExpression
82+
83+{-| A `check` constraint is the most generic `TableConstraint` type.
84+It allows you to specify that the value in a certain column must satisfy
85+a Boolean (truth-value) expression.
86+
87+>>> :{
88+type Schema = '[
89+ "tab" ::: 'Table ('[ "inequality" ::: 'Check '["a","b"]] :=> '[
90+ "a" ::: 'NoDef :=> 'NotNull 'PGint4,
91+ "b" ::: 'NoDef :=> 'NotNull 'PGint4
92+ ])]
93+:}
94+
95+>>> :{
96+let
97+ definition :: Definition (Public '[]) (Public Schema)
98+ definition = createTable #tab
99+ ( (int & notNullable) `as` #a :*
100+ (int & notNullable) `as` #b )
101+ ( check (#a :* #b) (#a .> #b) `as` #inequality )
102+:}
103+
104+>>> printSQL definition
105+CREATE TABLE "tab" ("a" int NOT NULL, "b" int NOT NULL, CONSTRAINT "inequality" CHECK (("a" > "b")));
106+-}
107+check
108+ :: ( Has sch schemas schema
109+ , Has tab schema ('Table table)
110+ , HasAll aliases (TableToRow table) subcolumns )
111+ => NP Alias aliases
112+ -- ^ specify the subcolumns which are getting checked
113+ -> (forall t. Condition '[] '[] 'Ungrouped schemas '[] '[t ::: subcolumns])
114+ -- ^ a closed `Condition` on those subcolumns
115+ -> TableConstraintExpression sch tab schemas ('Check aliases)
116+check _cols condition = UnsafeTableConstraintExpression $
117+ "CHECK" <+> parenthesized (renderSQL condition)
118+
119+{-| A `unique` constraint ensure that the data contained in a column,
120+or a group of columns, is unique among all the rows in the table.
121+
122+>>> :{
123+type Schema = '[
124+ "tab" ::: 'Table( '[ "uq_a_b" ::: 'Unique '["a","b"]] :=> '[
125+ "a" ::: 'NoDef :=> 'Null 'PGint4,
126+ "b" ::: 'NoDef :=> 'Null 'PGint4
127+ ])]
128+:}
129+
130+>>> :{
131+let
132+ definition :: Definition (Public '[]) (Public Schema)
133+ definition = createTable #tab
134+ ( (int & nullable) `as` #a :*
135+ (int & nullable) `as` #b )
136+ ( unique (#a :* #b) `as` #uq_a_b )
137+:}
138+
139+>>> printSQL definition
140+CREATE TABLE "tab" ("a" int NULL, "b" int NULL, CONSTRAINT "uq_a_b" UNIQUE ("a", "b"));
141+-}
142+unique
143+ :: ( Has sch schemas schema
144+ , Has tab schema('Table table)
145+ , HasAll aliases (TableToRow table) subcolumns )
146+ => NP Alias aliases
147+ -- ^ specify subcolumns which together are unique for each row
148+ -> TableConstraintExpression sch tab schemas ('Unique aliases)
149+unique columns = UnsafeTableConstraintExpression $
150+ "UNIQUE" <+> parenthesized (renderSQL columns)
151+
152+{-| A `primaryKey` constraint indicates that a column, or group of columns,
153+can be used as a unique identifier for rows in the table.
154+This requires that the values be both unique and not null.
155+
156+>>> :{
157+type Schema = '[
158+ "tab" ::: 'Table ('[ "pk_id" ::: 'PrimaryKey '["id"]] :=> '[
159+ "id" ::: 'Def :=> 'NotNull 'PGint4,
160+ "name" ::: 'NoDef :=> 'NotNull 'PGtext
161+ ])]
162+:}
163+
164+>>> :{
165+let
166+ definition :: Definition (Public '[]) (Public Schema)
167+ definition = createTable #tab
168+ ( serial `as` #id :*
169+ (text & notNullable) `as` #name )
170+ ( primaryKey #id `as` #pk_id )
171+:}
172+
173+>>> printSQL definition
174+CREATE TABLE "tab" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_id" PRIMARY KEY ("id"));
175+-}
176+primaryKey
177+ :: ( Has sch schemas schema
178+ , Has tab schema ('Table table)
179+ , HasAll aliases (TableToColumns table) subcolumns
180+ , AllNotNull subcolumns )
181+ => NP Alias aliases
182+ -- ^ specify the subcolumns which together form a primary key.
183+ -> TableConstraintExpression sch tab schemas ('PrimaryKey aliases)
184+primaryKey columns = UnsafeTableConstraintExpression $
185+ "PRIMARY KEY" <+> parenthesized (renderSQL columns)
186+
187+{-| A `foreignKey` specifies that the values in a column
188+(or a group of columns) must match the values appearing in some row of
189+another table. We say this maintains the referential integrity
190+between two related tables.
191+
192+>>> :{
193+type Schema =
194+ '[ "users" ::: 'Table (
195+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
196+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
197+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
198+ ])
199+ , "emails" ::: 'Table (
200+ '[ "pk_emails" ::: 'PrimaryKey '["id"]
201+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
202+ ] :=>
203+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
204+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
205+ , "email" ::: 'NoDef :=> 'Null 'PGtext
206+ ])
207+ ]
208+:}
209+
210+>>> :{
211+let
212+ setup :: Definition (Public '[]) (Public Schema)
213+ setup =
214+ createTable #users
215+ ( serial `as` #id :*
216+ (text & notNullable) `as` #name )
217+ ( primaryKey #id `as` #pk_users ) >>>
218+ createTable #emails
219+ ( serial `as` #id :*
220+ (int & notNullable) `as` #user_id :*
221+ (text & nullable) `as` #email )
222+ ( primaryKey #id `as` #pk_emails :*
223+ foreignKey #user_id #users #id
224+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
225+in printSQL setup
226+:}
227+CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));
228+CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);
229+
230+A `foreignKey` can even be a table self-reference.
231+
232+>>> :{
233+type Schema =
234+ '[ "employees" ::: 'Table (
235+ '[ "employees_pk" ::: 'PrimaryKey '["id"]
236+ , "employees_employer_fk" ::: 'ForeignKey '["employer_id"] "employees" '["id"]
237+ ] :=>
238+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
239+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
240+ , "employer_id" ::: 'NoDef :=> 'Null 'PGint4
241+ ])
242+ ]
243+:}
244+
245+>>> :{
246+let
247+ setup :: Definition (Public '[]) (Public Schema)
248+ setup =
249+ createTable #employees
250+ ( serial `as` #id :*
251+ (text & notNullable) `as` #name :*
252+ (integer & nullable) `as` #employer_id )
253+ ( primaryKey #id `as` #employees_pk :*
254+ foreignKey #employer_id #employees #id
255+ OnDeleteCascade OnUpdateCascade `as` #employees_employer_fk )
256+in printSQL setup
257+:}
258+CREATE TABLE "employees" ("id" serial, "name" text NOT NULL, "employer_id" integer NULL, CONSTRAINT "employees_pk" PRIMARY KEY ("id"), CONSTRAINT "employees_employer_fk" FOREIGN KEY ("employer_id") REFERENCES "employees" ("id") ON DELETE CASCADE ON UPDATE CASCADE);
259+-}
260+foreignKey
261+ :: (ForeignKeyed schemas sch schema child parent
262+ table reftable
263+ columns refcolumns
264+ constraints cols
265+ reftys tys )
266+ => NP Alias columns
267+ -- ^ column or columns in the table
268+ -> Alias parent
269+ -- ^ reference table
270+ -> NP Alias refcolumns
271+ -- ^ reference column or columns in the reference table
272+ -> OnDeleteClause
273+ -- ^ what to do when reference is deleted
274+ -> OnUpdateClause
275+ -- ^ what to do when reference is updated
276+ -> TableConstraintExpression sch child schemas
277+ ('ForeignKey columns parent refcolumns)
278+foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $
279+ "FOREIGN KEY" <+> parenthesized (renderSQL keys)
280+ <+> "REFERENCES" <+> renderSQL parent
281+ <+> parenthesized (renderSQL refs)
282+ <+> renderSQL ondel
283+ <+> renderSQL onupd
284+
285+-- | A constraint synonym between types involved in a foreign key constraint.
286+type ForeignKeyed schemas
287+ sch
288+ schema
289+ child parent
290+ table reftable
291+ columns refcolumns
292+ constraints cols
293+ reftys tys =
294+ ( Has sch schemas schema
295+ , Has child schema ('Table table)
296+ , Has parent schema ('Table reftable)
297+ , HasAll columns (TableToColumns table) tys
298+ , reftable ~ (constraints :=> cols)
299+ , HasAll refcolumns cols reftys
300+ , SOP.AllZip SamePGType tys reftys
301+ , Uniquely refcolumns constraints )
302+
303+-- | `OnDeleteClause` indicates what to do with rows that reference a deleted row.
304+data OnDeleteClause
305+ = OnDeleteNoAction
306+ -- ^ if any referencing rows still exist when the constraint is checked,
307+ -- an error is raised
308+ | OnDeleteRestrict -- ^ prevents deletion of a referenced row
309+ | OnDeleteCascade
310+ -- ^ specifies that when a referenced row is deleted,
311+ -- row(s) referencing it should be automatically deleted as well
312+ deriving (GHC.Generic,Show,Eq,Ord)
313+instance NFData OnDeleteClause
314+-- | Render `OnDeleteClause`.
315+instance RenderSQL OnDeleteClause where
316+ renderSQL = \case
317+ OnDeleteNoAction -> "ON DELETE NO ACTION"
318+ OnDeleteRestrict -> "ON DELETE RESTRICT"
319+ OnDeleteCascade -> "ON DELETE CASCADE"
320+
321+-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked
322+-- when a referenced column is changed (updated).
323+data OnUpdateClause
324+ = OnUpdateNoAction
325+ -- ^ if any referencing rows has not changed when the constraint is checked,
326+ -- an error is raised
327+ | OnUpdateRestrict -- ^ prevents update of a referenced row
328+ | OnUpdateCascade
329+ -- ^ the updated values of the referenced column(s) should be copied
330+ -- into the referencing row(s)
331+ deriving (GHC.Generic,Show,Eq,Ord)
332+instance NFData OnUpdateClause
333+
334+-- | Render `OnUpdateClause`.
335+instance RenderSQL OnUpdateClause where
336+ renderSQL = \case
337+ OnUpdateNoAction -> "ON UPDATE NO ACTION"
338+ OnUpdateRestrict -> "ON UPDATE RESTRICT"
339+ OnUpdateCascade -> "ON UPDATE CASCADE"
squeal-postgresql/src/Squeal/PostgreSQL/Definition/Type.hsnew file+229
@@ -0,0 +1,229 @@
1+{-|
2+Module: Squeal.PostgreSQL.Definition.Type
3+Description: Create and drop type definitions
4+Copyright: (c) Eitan Chatav, 2017
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Create and drop type definitions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DerivingStrategies
17+ , FlexibleContexts
18+ , FlexibleInstances
19+ , GADTs
20+ , LambdaCase
21+ , MultiParamTypeClasses
22+ , OverloadedLabels
23+ , OverloadedStrings
24+ , RankNTypes
25+ , ScopedTypeVariables
26+ , TypeApplications
27+ , TypeInType
28+ , TypeOperators
29+ , UndecidableSuperClasses
30+#-}
31+
32+module Squeal.PostgreSQL.Definition.Type
33+ ( createTypeEnum
34+ , createTypeEnumFrom
35+ , createTypeComposite
36+ , createTypeCompositeFrom
37+ , createTypeRange
38+ , createDomain
39+ , dropType
40+ , dropTypeIfExists
41+ ) where
42+
43+import Data.ByteString
44+import Data.Monoid
45+import GHC.TypeLits
46+import Prelude hiding ((.), id)
47+
48+import qualified Generics.SOP as SOP
49+
50+import Squeal.PostgreSQL.Alias
51+import Squeal.PostgreSQL.Expression.Logic
52+import Squeal.PostgreSQL.Expression.Type
53+import Squeal.PostgreSQL.Definition
54+import Squeal.PostgreSQL.List
55+import Squeal.PostgreSQL.PG
56+import Squeal.PostgreSQL.Render
57+import Squeal.PostgreSQL.Schema
58+
59+-- $setup
60+-- >>> import Squeal.PostgreSQL
61+-- >>> import qualified GHC.Generics as GHC
62+-- >>> import qualified Generics.SOP as SOP
63+
64+-- | Enumerated types are created using the `createTypeEnum` command, for example
65+--
66+-- >>> printSQL $ (createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy") :: Definition (Public '[]) '["public" ::: '["mood" ::: 'Typedef ('PGenum '["sad","ok","happy"])]])
67+-- CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');
68+createTypeEnum
69+ :: (KnownSymbol enum, Has sch schemas schema, SOP.All KnownSymbol labels)
70+ => QualifiedAlias sch enum
71+ -- ^ name of the user defined enumerated type
72+ -> NP PGlabel labels
73+ -- ^ labels of the enumerated type
74+ -> Definition schemas (Alter sch (Create enum ('Typedef ('PGenum labels)) schema) schemas)
75+createTypeEnum enum labels = UnsafeDefinition $
76+ "CREATE" <+> "TYPE" <+> renderSQL enum <+> "AS" <+> "ENUM" <+>
77+ parenthesized (renderSQL labels) <> ";"
78+
79+-- | Enumerated types can also be generated from a Haskell type, for example
80+--
81+-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
82+-- >>> instance SOP.Generic Schwarma
83+-- >>> instance SOP.HasDatatypeInfo Schwarma
84+-- >>> :{
85+-- let
86+-- createSchwarma :: Definition (Public '[]) '["public" ::: '["schwarma" ::: 'Typedef (PG (Enumerated Schwarma))]]
87+-- createSchwarma = createTypeEnumFrom @Schwarma #schwarma
88+-- in
89+-- printSQL createSchwarma
90+-- :}
91+-- CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');
92+createTypeEnumFrom
93+ :: forall hask sch enum schemas schema.
94+ ( SOP.Generic hask
95+ , SOP.All KnownSymbol (LabelsPG hask)
96+ , KnownSymbol enum
97+ , Has sch schemas schema )
98+ => QualifiedAlias sch enum
99+ -- ^ name of the user defined enumerated type
100+ -> Definition schemas (Alter sch (Create enum ('Typedef (PG (Enumerated hask))) schema) schemas)
101+createTypeEnumFrom enum = createTypeEnum enum
102+ (SOP.hpure label :: NP PGlabel (LabelsPG hask))
103+
104+{- | `createTypeComposite` creates a composite type. The composite type is
105+specified by a list of attribute names and data types.
106+
107+>>> :{
108+type PGcomplex = 'PGcomposite
109+ '[ "real" ::: 'NotNull 'PGfloat8
110+ , "imaginary" ::: 'NotNull 'PGfloat8 ]
111+:}
112+
113+>>> :{
114+let
115+ setup :: Definition (Public '[]) '["public" ::: '["complex" ::: 'Typedef PGcomplex]]
116+ setup = createTypeComposite #complex
117+ (float8 `as` #real :* float8 `as` #imaginary)
118+in printSQL setup
119+:}
120+CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
121+-}
122+createTypeComposite
123+ :: (KnownSymbol ty, Has sch schemas schema, SOP.SListI fields)
124+ => QualifiedAlias sch ty
125+ -- ^ name of the user defined composite type
126+ -> NP (Aliased (TypeExpression schemas)) fields
127+ -- ^ list of attribute names and data types
128+ -> Definition schemas (Alter sch (Create ty ('Typedef ('PGcomposite fields)) schema) schemas)
129+createTypeComposite ty fields = UnsafeDefinition $
130+ "CREATE" <+> "TYPE" <+> renderSQL ty <+> "AS" <+> parenthesized
131+ (renderCommaSeparated renderField fields) <> ";"
132+ where
133+ renderField :: Aliased (TypeExpression schemas) x -> ByteString
134+ renderField (typ `As` alias) =
135+ renderSQL alias <+> renderSQL typ
136+
137+-- | Composite types can also be generated from a Haskell type, for example
138+--
139+-- >>> data Complex = Complex {real :: Double, imaginary :: Double} deriving GHC.Generic
140+-- >>> instance SOP.Generic Complex
141+-- >>> instance SOP.HasDatatypeInfo Complex
142+-- >>> type Schema = '["complex" ::: 'Typedef (PG (Composite Complex))]
143+-- >>> :{
144+-- let
145+-- createComplex :: Definition (Public '[]) (Public Schema)
146+-- createComplex = createTypeCompositeFrom @Complex #complex
147+-- in
148+-- printSQL createComplex
149+-- :}
150+-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
151+createTypeCompositeFrom
152+ :: forall hask sch ty schemas schema.
153+ ( SOP.All (FieldTyped schemas) (RowPG hask)
154+ , KnownSymbol ty
155+ , Has sch schemas schema )
156+ => QualifiedAlias sch ty
157+ -- ^ name of the user defined composite type
158+ -> Definition schemas (Alter sch (Create ty ( 'Typedef (PG (Composite hask))) schema) schemas)
159+createTypeCompositeFrom ty = createTypeComposite ty
160+ (SOP.hcpure (SOP.Proxy :: SOP.Proxy (FieldTyped schemas)) fieldtype
161+ :: NP (Aliased (TypeExpression schemas)) (RowPG hask))
162+
163+{-|
164+`createDomain` creates a new domain. A domain is essentially a data type
165+with constraints (restrictions on the allowed set of values).
166+
167+Domains are useful for abstracting common constraints on fields
168+into a single location for maintenance. For example, several tables might
169+contain email address columns, all requiring the same `check` constraint
170+to verify the address syntax. Define a domain rather than setting up
171+each table's constraint individually.
172+
173+>>> :{
174+let
175+ createPositive :: Definition (Public '[]) (Public '["positive" ::: 'Typedef 'PGfloat4])
176+ createPositive = createDomain #positive real (#value .> 0 .&& (#value & isNotNull))
177+in printSQL createPositive
178+:}
179+CREATE DOMAIN "positive" AS real CHECK ((("value" > 0) AND "value" IS NOT NULL));
180+-}
181+createDomain
182+ :: (Has sch schemas schema, KnownSymbol dom)
183+ => QualifiedAlias sch dom
184+ -> (forall null. TypeExpression schemas (null ty))
185+ -> (forall tab. Condition '[] '[] 'Ungrouped schemas '[] '[tab ::: '["value" ::: 'Null ty]])
186+ -> Definition schemas (Alter sch (Create dom ('Typedef ty) schema) schemas)
187+createDomain dom ty condition =
188+ UnsafeDefinition $ "CREATE DOMAIN" <+> renderSQL dom
189+ <+> "AS" <+> renderTypeExpression ty
190+ <+> "CHECK" <+> parenthesized (renderSQL condition) <> ";"
191+
192+{- |
193+>>> :{
194+let
195+ createSmallIntRange :: Definition (Public '[]) (Public '["int2range" ::: 'Typedef ('PGrange 'PGint2)])
196+ createSmallIntRange = createTypeRange #int2range int2
197+in printSQL createSmallIntRange
198+:}
199+CREATE TYPE "int2range" AS RANGE (subtype = int2);
200+-}
201+createTypeRange
202+ :: (Has sch schemas schema, KnownSymbol range)
203+ => QualifiedAlias sch range
204+ -> (forall null. TypeExpression schemas (null ty))
205+ -> Definition schemas (Alter sch (Create range ('Typedef ('PGrange ty)) schema) schemas)
206+createTypeRange range ty = UnsafeDefinition $
207+ "CREATE" <+> "TYPE" <+> renderSQL range <+> "AS" <+> "RANGE" <+>
208+ parenthesized ("subtype" <+> "=" <+> renderTypeExpression ty) <> ";"
209+
210+-- | Drop a type.
211+--
212+-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
213+-- >>> instance SOP.Generic Schwarma
214+-- >>> instance SOP.HasDatatypeInfo Schwarma
215+-- >>> printSQL (dropType #schwarma :: Definition '["public" ::: '["schwarma" ::: 'Typedef (PG (Enumerated Schwarma))]] (Public '[]))
216+-- DROP TYPE "schwarma";
217+dropType
218+ :: (Has sch schemas schema, KnownSymbol td)
219+ => QualifiedAlias sch td
220+ -- ^ name of the user defined type
221+ -> Definition schemas (Alter sch (DropSchemum td 'Typedef schema) schemas)
222+dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderSQL tydef <> ";"
223+
224+dropTypeIfExists
225+ :: (Has sch schemas schema, KnownSymbol td)
226+ => QualifiedAlias sch td
227+ -- ^ name of the user defined type
228+ -> Definition schemas (Alter sch (DropSchemumIfExists td 'Typedef schema) schemas)
229+dropTypeIfExists tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderSQL tydef <> ";"
squeal-postgresql/src/Squeal/PostgreSQL/Definition/View.hsnew file+104
@@ -0,0 +1,104 @@
1+{-|
2+Module: Squeal.PostgreSQL.Definition.View
3+Description: Create and drop view definitions
4+Copyright: (c) Eitan Chatav, 2017
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Create and drop view definitions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DerivingStrategies
17+ , FlexibleContexts
18+ , FlexibleInstances
19+ , GADTs
20+ , LambdaCase
21+ , MultiParamTypeClasses
22+ , OverloadedLabels
23+ , OverloadedStrings
24+ , RankNTypes
25+ , ScopedTypeVariables
26+ , TypeApplications
27+ , TypeInType
28+ , TypeOperators
29+ , UndecidableSuperClasses
30+#-}
31+
32+module Squeal.PostgreSQL.Definition.View
33+ ( createView
34+ , createOrReplaceView
35+ , dropView
36+ , dropViewIfExists
37+ ) where
38+
39+import GHC.TypeLits
40+
41+import Squeal.PostgreSQL.Alias
42+import Squeal.PostgreSQL.Definition
43+import Squeal.PostgreSQL.Query
44+import Squeal.PostgreSQL.Render
45+import Squeal.PostgreSQL.Schema
46+
47+-- $setup
48+-- >>> import Squeal.PostgreSQL
49+
50+{- | Create a view.
51+>>> type ABC = '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4]
52+>>> type BC = '["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4]
53+>>> :{
54+let
55+ definition :: Definition
56+ '[ "public" ::: '["abc" ::: 'Table ('[] :=> ABC)]]
57+ '[ "public" ::: '["abc" ::: 'Table ('[] :=> ABC), "bc" ::: 'View BC]]
58+ definition =
59+ createView #bc (select_ (#b :* #c) (from (table #abc)))
60+in printSQL definition
61+:}
62+CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";
63+-}
64+createView
65+ :: (Has sch schemas schema, KnownSymbol vw)
66+ => QualifiedAlias sch vw -- ^ the name of the view to add
67+ -> Query '[] '[] schemas '[] view -- ^ query
68+ -> Definition schemas (Alter sch (Create vw ('View view) schema) schemas)
69+createView alias query = UnsafeDefinition $
70+ "CREATE" <+> "VIEW" <+> renderSQL alias <+> "AS"
71+ <+> renderQuery query <> ";"
72+
73+createOrReplaceView
74+ :: (Has sch schemas schema, KnownSymbol vw)
75+ => QualifiedAlias sch vw -- ^ the name of the view to add
76+ -> Query '[] '[] schemas '[] view -- ^ query
77+ -> Definition schemas (Alter sch (CreateOrReplace vw ('View view) schema) schemas)
78+createOrReplaceView alias query = UnsafeDefinition $
79+ "CREATE OR REPLACE VIEW" <+> renderSQL alias <+> "AS"
80+ <+> renderQuery query <> ";"
81+
82+-- | Drop a view.
83+--
84+-- >>> :{
85+-- let
86+-- definition :: Definition
87+-- '[ "public" ::: '["abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])
88+-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]]
89+-- '[ "public" ::: '["abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]]
90+-- definition = dropView #bc
91+-- in printSQL definition
92+-- :}
93+-- DROP VIEW "bc";
94+dropView
95+ :: (Has sch schemas schema, KnownSymbol vw)
96+ => QualifiedAlias sch vw -- ^ view to remove
97+ -> Definition schemas (Alter sch (DropSchemum vw 'View schema) schemas)
98+dropView vw = UnsafeDefinition $ "DROP VIEW" <+> renderSQL vw <> ";"
99+
100+dropViewIfExists
101+ :: (Has sch schemas schema, KnownSymbol vw)
102+ => QualifiedAlias sch vw -- ^ view to remove
103+ -> Definition schemas (Alter sch (DropIfExists vw schema) schemas)
104+dropViewIfExists vw = UnsafeDefinition $ "DROP VIEW IF EXISTS" <+> renderSQL vw <> ";"
squeal-postgresql/src/Squeal/PostgreSQL/Expression.hs+341−1487
@@ -1,14 +1,13 @@
1{-|
1{-|
2−Module: Squeal.PostgreSQL.Query
2+Module: Squeal.PostgreSQL.Expression
3Description: Squeal expressions
3Description: Squeal expressions
4−Copyright: (c) Eitan Chatav, 2017
4+Copyright: (c) Eitan Chatav, 2019
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
8Squeal expressions are the atoms used to build statements.
8Squeal expressions are the atoms used to build statements.
9-}
9-}
10
10
11−{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
12{-# LANGUAGE
11{-# LANGUAGE
13 AllowAmbiguousTypes
12 AllowAmbiguousTypes
14 , ConstraintKinds
13 , ConstraintKinds
@@ -16,11 +15,13 @@ Squeal expressions are the atoms used to build statements.
16 , FlexibleContexts
15 , FlexibleContexts
17 , FlexibleInstances
16 , FlexibleInstances
18 , FunctionalDependencies
17 , FunctionalDependencies
18+ , GADTs
19 , GeneralizedNewtypeDeriving
19 , GeneralizedNewtypeDeriving
20 , LambdaCase
20 , LambdaCase
21 , MagicHash
21 , MagicHash
22 , OverloadedStrings
22 , OverloadedStrings
23 , ScopedTypeVariables
23 , ScopedTypeVariables
24+ , StandaloneDeriving
24 , TypeApplications
25 , TypeApplications
25 , TypeFamilies
26 , TypeFamilies
26 , TypeInType
27 , TypeInType
@@ -31,508 +32,351 @@ Squeal expressions are the atoms used to build statements.
31
32
32module Squeal.PostgreSQL.Expression
33module Squeal.PostgreSQL.Expression
33 ( -- * Expression
34 ( -- * Expression
34− Expression (UnsafeExpression, renderExpression)
35+ Expression (..)
35− , HasParameter (parameter)
36+ , Expr
36− , param
37+ , type (-->)
37− -- ** Null
38+ , FunctionDB
38− , null_
39− , notNull
40− , coalesce
41− , fromNull
42− , isNull
43− , isNotNull
44− , matchNull
45− , nullIf
46− -- ** Collections
47− , array
48− , row
49− -- ** Functions
50− , unsafeBinaryOp
51− , unsafeUnaryOp
52 , unsafeFunction
39 , unsafeFunction
53− , unsafeVariadicFunction
40+ , function
54− , atan2_
41+ , unsafeLeftOp
55− , cast
42+ , leftOp
56− , quot_
43+ , unsafeRightOp
57− , rem_
44+ , rightOp
58− , trunc
45+ , Operator
59− , round_
46+ , OperatorDB
60− , ceiling_
47+ , unsafeBinaryOp
61− , greatest
48+ , binaryOp
62− , least
49+ , FunctionVar
63− -- ** Conditions
50+ , unsafeFunctionVar
64− , Condition
51+ , type (--->)
65− , true
52+ , FunctionNDB
66− , false
53+ , unsafeFunctionN
67− , not_
54+ , functionN
68− , (.&&)
55+ , PGSubset (..)
69− , (.||)
56+ , PGIntersect (..)
70− , caseWhenThenElse
71− , ifThenElse
72− , (.==)
73− , (./=)
74− , (.>=)
75− , (.<)
76− , (.<=)
77− , (.>)
78− -- ** Time
79− , currentDate
80− , currentTime
81− , currentTimestamp
82− , localTime
83− , localTimestamp
84− -- ** Text
85− , lower
86− , upper
87− , charLength
88− , like
89− -- ** json or jsonb operators
90− , PGarray
91− , PGarrayOf
92− , PGjsonKey
93− , PGjson_
94− , PGobjectpairs
95− , (.->)
96− , (.->>)
97− , (.#>)
98− , (.#>>)
99− -- *** jsonb only operators
100− , (.@>)
101− , (.<@)
102− , (.?)
103− , (.?|)
104− , (.?&)
105− , (.||.)
106− , (.-.)
107− , (#-.)
108− -- *** Functions
109− , toJson
110− , toJsonb
111− , arrayToJson
112− , rowToJson
113− , jsonBuildArray
114− , jsonbBuildArray
115− , jsonBuildObject
116− , jsonbBuildObject
117− , jsonObject
118− , jsonbObject
119− , jsonZipObject
120− , jsonbZipObject
121− , jsonArrayLength
122− , jsonbArrayLength
123− , jsonExtractPath
124− , jsonbExtractPath
125− , jsonExtractPathAsText
126− , jsonbExtractPathAsText
127− , jsonObjectKeys
128− , jsonbObjectKeys
129− , jsonTypeof
130− , jsonbTypeof
131− -- ** Aggregation
132− , unsafeAggregate, unsafeAggregateDistinct
133− , sum_, sumDistinct
134− , PGAvg (avg, avgDistinct)
135− , bitAnd, bitOr, boolAnd, boolOr
136− , bitAndDistinct, bitOrDistinct, boolAndDistinct, boolOrDistinct
137− , countStar
138− , count, countDistinct
139− , every, everyDistinct
140− , max_, maxDistinct, min_, minDistinct
141− -- * Types
142− , TypeExpression (UnsafeTypeExpression, renderTypeExpression)
143− , PGTyped (pgtype)
144− , bool
145− , int2
146− , smallint
147− , int4
148− , int
149− , integer
150− , int8
151− , bigint
152− , numeric
153− , float4
154− , real
155− , float8
156− , doublePrecision
157− , text
158− , char
159− , character
160− , varchar
161− , characterVarying
162− , bytea
163− , timestamp
164− , timestampWithTimeZone
165− , date
166− , time
167− , timeWithTimeZone
168− , interval
169− , uuid
170− , inet
171− , json
172− , jsonb
173− , vararray
174− , fixarray
175 -- * Re-export
57 -- * Re-export
176 , (&)
58 , (&)
177− , NP ((:*), Nil)
59+ , K (..)
60+ , unK
178 ) where
61 ) where
179
62
180import Control.Category
63import Control.Category
181import Control.DeepSeq
64import Control.DeepSeq
182import Data.ByteString (ByteString)
65import Data.ByteString (ByteString)
183import Data.Function ((&))
66import Data.Function ((&))
184−import Data.Semigroup
67+import Data.Semigroup hiding (All)
185−import Data.Ratio
186import Data.String
68import Data.String
187−import Generics.SOP hiding (from)
69+import Generics.SOP hiding (All, from)
188import GHC.OverloadedLabels
70import GHC.OverloadedLabels
189import GHC.TypeLits
71import GHC.TypeLits
72+import Numeric
190import Prelude hiding (id, (.))
73import Prelude hiding (id, (.))
191
74
192import qualified GHC.Generics as GHC
75import qualified GHC.Generics as GHC
193
76
77+import Squeal.PostgreSQL.Alias
78+import Squeal.PostgreSQL.List
194import Squeal.PostgreSQL.Render
79import Squeal.PostgreSQL.Render
195import Squeal.PostgreSQL.Schema
80import Squeal.PostgreSQL.Schema
196
81
82+-- $setup
83+-- >>> import Squeal.PostgreSQL
84+
197{-----------------------------------------
85{-----------------------------------------
198column expressions
86column expressions
199-----------------------------------------}
87-----------------------------------------}
200
88
201{- | `Expression`s are used in a variety of contexts,
89{- | `Expression`s are used in a variety of contexts,
90+such as in the target `Squeal.PostgreSQL.Query.List` of the
202−such as in the target list of the `Squeal.PostgreSQL.Query.select` command,
91+`Squeal.PostgreSQL.Query.select` command,
203as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or
92as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or
204`Squeal.PostgreSQL.Manipulation.update`,
93`Squeal.PostgreSQL.Manipulation.update`,
205−or in search `Condition`s in a number of commands.
94+or in search `Squeal.PostgreSQL.Logic.Condition`s in a number of commands.
206
95
207The expression syntax allows the calculation of
96The expression syntax allows the calculation of
208values from primitive expression using arithmetic, logical,
97values from primitive expression using arithmetic, logical,
209and other operations.
98and other operations.
99+
100+The type parameters of `Expression` are
101+
102+* @outer :: @ `FromType`, the @from@ clauses of any outer queries in which
103+ the `Expression` is a correlated subquery expression;
104+* @commons :: @ `FromType`, the `Squeal.PostgreSQL.Query.CommonTableExpression`s
105+ that are in scope for the `Expression`;
106+* @grp :: @ `Grouping`, the `Grouping` of the @from@ clause which may limit
107+ which columns may be referenced by alias;
108+* @schemas :: @ `SchemasType`, the schemas of your database that are in
109+ scope for the `Expression`;
110+* @from :: @ `FromType`, the @from@ clause which the `Expression` may use
111+ to reference columns by alias;
112+* @ty :: @ `NullityType`, the type of the `Expression`.
210-}
113-}
211newtype Expression
114newtype Expression
212− (schema :: SchemaType)
115+ (outer :: FromType)
213− (relations :: RelationsType)
116+ (commons :: FromType)
214− (grouping :: Grouping)
117+ (grp :: Grouping)
118+ (schemas :: SchemasType)
215 (params :: [NullityType])
119 (params :: [NullityType])
120+ (from :: FromType)
216 (ty :: NullityType)
121 (ty :: NullityType)
217 = UnsafeExpression { renderExpression :: ByteString }
122 = UnsafeExpression { renderExpression :: ByteString }
218 deriving (GHC.Generic,Show,Eq,Ord,NFData)
123 deriving (GHC.Generic,Show,Eq,Ord,NFData)
219−
220−instance RenderSQL (Expression schema relations grouping params ty) where
124+instance RenderSQL (Expression outer commons grp schemas params from ty) where
221 renderSQL = renderExpression
125 renderSQL = renderExpression
222
126
223−{- | A `HasParameter` constraint is used to indicate a value that is
127+-- | An `Expr` is a closed `Expression`.
224−supplied externally to a SQL statement.
128+-- It is a F@RankNType@ but don't be scared.
225−`Squeal.PostgreSQL.PQ.manipulateParams`,
129+-- Think of it as an expression which sees no
226−`Squeal.PostgreSQL.PQ.queryParams` and
130+-- namespaces, so you can't use parameters
227−`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values
131+-- or alias references. It can be used as
228−separately from the SQL command string, in which case `param`s are used to
132+-- a simple piece of more complex `Expression`s.
229−refer to the out-of-line data values.
133+type Expr x
134+ = forall outer commons grp schemas params from
135+ . Expression outer commons grp schemas params from x
136+ -- ^ cannot reference aliases
137+
138+-- | A @RankNType@ for binary operators.
139+type Operator x1 x2 y
140+ = forall outer commons grp schemas params from
141+ . Expression outer commons grp schemas params from x1
142+ -- ^ left input
143+ -> Expression outer commons grp schemas params from x2
144+ -- ^ right input
145+ -> Expression outer commons grp schemas params from y
146+ -- ^ output
147+
148+type OperatorDB schemas x1 x2 y
149+ = forall outer commons grp params from
150+ . Expression outer commons grp schemas params from x1
151+ -- ^ left input
152+ -> Expression outer commons grp schemas params from x2
153+ -- ^ right input
154+ -> Expression outer commons grp schemas params from y
155+ -- ^ output
156+
157+-- | A @RankNType@ for functions with a single argument.
158+-- These could be either function calls or unary operators.
159+-- This is a subtype of the usual Haskell function type `Prelude.->`,
160+-- indeed a subcategory as it is closed under the usual
161+-- `Prelude..` and `Prelude.id`.
162+type (-->) x y
163+ = forall outer commons grp schemas params from
164+ . Expression outer commons grp schemas params from x
165+ -- ^ input
166+ -> Expression outer commons grp schemas params from y
167+ -- ^ output
168+
169+type FunctionDB schemas x y
170+ = forall outer commons grp params from
171+ . Expression outer commons grp schemas params from x
172+ -- ^ input
173+ -> Expression outer commons grp schemas params from y
174+ -- ^ output
175+
176+{- | A @RankNType@ for functions with a fixed-length list of heterogeneous arguments.
177+Use the `*:` operator to end your argument lists, like so.
178+
179+>>> printSQL (unsafeFunctionN "fun" (true :* false :* localTime *: true))
180+fun(TRUE, FALSE, LOCALTIME, TRUE)
230-}
181-}
231−class KnownNat n => HasParameter
182+type (--->) xs y
232− (n :: Nat)
183+ = forall outer commons grp schemas params from
233− (schema :: SchemaType)
184+ . NP (Expression outer commons grp schemas params from) xs
234− (params :: [NullityType])
185+ -- ^ inputs
235− (ty :: NullityType)
186+ -> Expression outer commons grp schemas params from y
236− | n params -> ty where
187+ -- ^ output
237− -- | `parameter` takes a `Nat` using type application and a `TypeExpression`.
188+
238− --
189+type FunctionNDB schemas xs y
239− -- >>> let expr = parameter @1 int4 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)
190+ = forall outer commons grp params from
240− -- >>> printSQL expr
191+ . NP (Expression outer commons grp schemas params from) xs
241− -- ($1 :: int4)
192+ -- ^ inputs
242− parameter
193+ -> Expression outer commons grp schemas params from y
243− :: TypeExpression schema (PGTypeOf ty)
194+ -- ^ output
244− -> Expression schema relations grouping params ty
195+
196+{- | A @RankNType@ for functions with a variable-length list of
197+homogeneous arguments and at least 1 more argument.
198+-}
199+type FunctionVar x0 x1 y
200+ = forall outer commons grp schemas params from
201+ . [Expression outer commons grp schemas params from x0]
202+ -- ^ inputs
203+ -> Expression outer commons grp schemas params from x1
204+ -- ^ must have at least 1 input
205+ -> Expression outer commons grp schemas params from y
206+ -- ^ output
207+
208+{- | >>> printSQL (unsafeFunctionVar "greatest" [true, null_] false)
209+greatest(TRUE, NULL, FALSE)
210+-}
211+unsafeFunctionVar :: ByteString -> FunctionVar x0 x1 y
245− parameter ty = UnsafeExpression $ parenthesized $
212+unsafeFunctionVar fun xs x = UnsafeExpression $ fun <> parenthesized
246− "$" <> renderNat (Proxy @n) <+> "::"
213+ (commaSeparated (renderSQL <$> xs) <> ", " <> renderSQL x)
247− <+> renderTypeExpression ty
214+
248−instance {-# OVERLAPPING #-} HasParameter 1 schema (ty1:tys) ty1
215+instance (HasUnique tab (Join outer from) row, Has col row ty)
249−instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) schema params ty)
216+ => IsLabel col (Expression outer commons 'Ungrouped schemas params from ty) where
250− => HasParameter n schema (ty' : params) ty
217+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)
251−
218+instance (HasUnique tab (Join outer from) row, Has col row ty, tys ~ '[ty])
252−-- | `param` takes a `Nat` using type application and for basic types,
219+ => IsLabel col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where
253−-- infers a `TypeExpression`.
220+ fromLabel = fromLabel @col :* Nil
254−--
255−-- >>> let expr = param @1 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)
256−-- >>> printSQL expr
257−-- ($1 :: int4)
258−param
259− :: forall n schema params relations grouping ty
260− . (PGTyped schema (PGTypeOf ty), HasParameter n schema params ty)
261− => Expression schema relations grouping params ty -- ^ param
262−param = parameter @n pgtype
263−
264−instance (HasUnique relation relations columns, Has column columns ty)
221+instance (HasUnique tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))
222+ => IsLabel col
265− => IsLabel column (Expression schema relations 'Ungrouped params ty) where
223+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where
266− fromLabel = UnsafeExpression $ renderAlias (Alias @column)
224+ fromLabel = fromLabel @col `As` Alias
267−instance (HasUnique relation relations columns, Has column columns ty)
225+instance (HasUnique tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])
268− => IsLabel column
226+ => IsLabel col
269− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where
227+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where
270− fromLabel = fromLabel @column `As` Alias @column
228+ fromLabel = fromLabel @col :* Nil
271−instance (HasUnique relation relations columns, Has column columns ty)
229+
272− => IsLabel column
230+instance (Has tab (Join outer from) row, Has col row ty)
273− (NP (Aliased (Expression schema relations 'Ungrouped params)) '[column ::: ty]) where
231+ => IsQualified tab col (Expression outer commons 'Ungrouped schemas params from ty) where
274− fromLabel = fromLabel @column :* Nil
232+ tab ! col = UnsafeExpression $
275−
233+ renderSQL tab <> "." <> renderSQL col
276−instance (Has relation relations columns, Has column columns ty)
234+instance (Has tab (Join outer from) row, Has col row ty, tys ~ '[ty])
277− => IsQualified relation column (Expression schema relations 'Ungrouped params ty) where
235+ => IsQualified tab col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where
278− relation ! column = UnsafeExpression $
236+ tab ! col = tab ! col :* Nil
279− renderAlias relation <> "." <> renderAlias column
280−instance (Has relation relations columns, Has column columns ty)
237+instance (Has tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))
281− => IsQualified relation column
238+ => IsQualified tab col
282− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where
239+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where
283− relation ! column = relation ! column `As` column
240+ tab ! col = tab ! col `As` col
284−instance (Has relation relations columns, Has column columns ty)
241+instance (Has tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])
285− => IsQualified relation column
242+ => IsQualified tab col
286− (NP (Aliased (Expression schema relations 'Ungrouped params)) '[column ::: ty]) where
243+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where
287− relation ! column = relation ! column :* Nil
244+ tab ! col = tab ! col :* Nil
288
245
289instance
246instance
290− ( HasUnique relation relations columns
247+ ( HasUnique tab (Join outer from) row
291− , Has column columns ty
248+ , Has col row ty
292− , GroupedBy relation column bys
249+ , GroupedBy tab col bys
293− ) => IsLabel column
250+ ) => IsLabel col
294− (Expression schema relations ('Grouped bys) params ty) where
251+ (Expression outer commons ('Grouped bys) schemas params from ty) where
295− fromLabel = UnsafeExpression $ renderAlias (Alias @column)
252+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)
253+instance
254+ ( HasUnique tab (Join outer from) row
255+ , Has col row ty
256+ , GroupedBy tab col bys
257+ , tys ~ '[ty]
258+ ) => IsLabel col
259+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where
260+ fromLabel = fromLabel @col :* Nil
296instance
261instance
297− ( HasUnique relation relations columns
262+ ( HasUnique tab (Join outer from) row
298− , Has column columns ty
263+ , Has col row ty
299− , GroupedBy relation column bys
264+ , GroupedBy tab col bys
265+ , column ~ (col ::: ty)
300− ) => IsLabel column
266+ ) => IsLabel col
301− ( Aliased (Expression schema relations ('Grouped bys) params)
267+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where
302− (column ::: ty) ) where
303− fromLabel = fromLabel @column `As` Alias @column
268+ fromLabel = fromLabel @col `As` Alias
304instance
269instance
305− ( HasUnique relation relations columns
270+ ( HasUnique tab (Join outer from) row
306− , Has column columns ty
271+ , Has col row ty
307− , GroupedBy relation column bys
272+ , GroupedBy tab col bys
273+ , columns ~ '[col ::: ty]
308− ) => IsLabel column
274+ ) => IsLabel col
309− ( NP (Aliased (Expression schema relations ('Grouped bys) params))
275+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where
310− '[column ::: ty] ) where
311− fromLabel = fromLabel @column :* Nil
276+ fromLabel = fromLabel @col :* Nil
312
277
313instance
278instance
314− ( Has relation relations columns
279+ ( Has tab (Join outer from) row
315− , Has column columns ty
280+ , Has col row ty
316− , GroupedBy relation column bys
281+ , GroupedBy tab col bys
317− ) => IsQualified relation column
282+ ) => IsQualified tab col
318− (Expression schema relations ('Grouped bys) params ty) where
283+ (Expression outer commons ('Grouped bys) schemas params from ty) where
319− relation ! column = UnsafeExpression $
284+ tab ! col = UnsafeExpression $
320− renderAlias relation <> "." <> renderAlias column
285+ renderSQL tab <> "." <> renderSQL col
321instance
286instance
322− ( Has relation relations columns
287+ ( Has tab (Join outer from) row
323− , Has column columns ty
288+ , Has col row ty
324− , GroupedBy relation column bys
289+ , GroupedBy tab col bys
290+ , tys ~ '[ty]
325− ) => IsQualified relation column
291+ ) => IsQualified tab col
326− (Aliased (Expression schema relations ('Grouped bys) params)
292+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where
327− (column ::: ty)) where
293+ tab ! col = tab ! col :* Nil
328− relation ! column = relation ! column `As` column
329instance
294instance
330− ( Has relation relations columns
295+ ( Has tab (Join outer from) row
331− , Has column columns ty
296+ , Has col row ty
332− , GroupedBy relation column bys
297+ , GroupedBy tab col bys
298+ , column ~ (col ::: ty)
333− ) => IsQualified relation column
299+ ) => IsQualified tab col
300+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where
301+ tab ! col = tab ! col `As` col
302+instance
303+ ( Has tab (Join outer from) row
304+ , Has col row ty
305+ , GroupedBy tab col bys
306+ , columns ~ '[col ::: ty]
307+ ) => IsQualified tab col
334− ( NP (Aliased (Expression schema relations ('Grouped bys) params))
308+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where
335− '[column ::: ty]) where
309+ tab ! col = tab ! col :* Nil
336− relation ! column = relation ! column :* Nil
337−
338−-- | analagous to `Nothing`
339−--
340−-- >>> printSQL null_
341−-- NULL
342−null_ :: Expression schema rels grouping params ('Null ty)
343−null_ = UnsafeExpression "NULL"
344−
345−-- | analagous to `Just`
346−--
347−-- >>> printSQL $ notNull true
348−-- TRUE
349−notNull
350− :: Expression schema rels grouping params ('NotNull ty)
351− -> Expression schema rels grouping params ('Null ty)
352−notNull = UnsafeExpression . renderExpression
353−
354−-- | return the leftmost value which is not NULL
355−--
356−-- >>> printSQL $ coalesce [null_, notNull true] false
357−-- COALESCE(NULL, TRUE, FALSE)
358−coalesce
359− :: [Expression schema relations grouping params ('Null ty)]
360− -- ^ @NULL@s may be present
361− -> Expression schema relations grouping params ('NotNull ty)
362− -- ^ @NULL@ is absent
363− -> Expression schema relations grouping params ('NotNull ty)
364−coalesce nullxs notNullx = UnsafeExpression $
365− "COALESCE" <> parenthesized (commaSeparated
366− ((renderExpression <$> nullxs) <> [renderExpression notNullx]))
367−
368−-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@
369−--
370−-- >>> printSQL $ fromNull true null_
371−-- COALESCE(NULL, TRUE)
372−fromNull
373− :: Expression schema relations grouping params ('NotNull ty)
374− -- ^ what to convert @NULL@ to
375− -> Expression schema relations grouping params ('Null ty)
376− -> Expression schema relations grouping params ('NotNull ty)
377−fromNull notNullx nullx = coalesce [nullx] notNullx
378−
379−-- | >>> printSQL $ null_ & isNull
380−-- NULL IS NULL
381−isNull
382− :: Expression schema relations grouping params ('Null ty)
383− -- ^ possibly @NULL@
384− -> Condition schema relations grouping params
385−isNull x = UnsafeExpression $ renderExpression x <+> "IS NULL"
386−
387−-- | >>> printSQL $ null_ & isNotNull
388−-- NULL IS NOT NULL
389−isNotNull
390− :: Expression schema relations grouping params ('Null ty)
391− -- ^ possibly @NULL@
392− -> Condition schema relations grouping params
393−isNotNull x = UnsafeExpression $ renderExpression x <+> "IS NOT NULL"
394−
395−-- | analagous to `maybe` using @IS NULL@
396−--
397−-- >>> printSQL $ matchNull true not_ null_
398−-- CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END
399−matchNull
400− :: Expression schema relations grouping params (nullty)
401− -- ^ what to convert @NULL@ to
402− -> ( Expression schema relations grouping params ('NotNull ty)
403− -> Expression schema relations grouping params (nullty) )
404− -- ^ function to perform when @NULL@ is absent
405− -> Expression schema relations grouping params ('Null ty)
406− -> Expression schema relations grouping params (nullty)
407−matchNull y f x = ifThenElse (isNull x) y
408− (f (UnsafeExpression (renderExpression x)))
409−
410−{-| right inverse to `fromNull`, if its arguments are equal then
411−`nullIf` gives @NULL@.
412−
413−>>> :set -XTypeApplications -XDataKinds
414−>>> let expr = nullIf false (param @1) :: Expression schema rels grp '[ 'NotNull 'PGbool] ('Null 'PGbool)
415−>>> printSQL expr
416−NULL IF (FALSE, ($1 :: bool))
417−-}
418−nullIf
419− :: Expression schema relations grouping params ('NotNull ty)
420− -- ^ @NULL@ is absent
421− -> Expression schema relations grouping params ('NotNull ty)
422− -- ^ @NULL@ is absent
423− -> Expression schema relations grouping params ('Null ty)
424−nullIf x y = UnsafeExpression $ "NULL IF" <+> parenthesized
425− (renderExpression x <> ", " <> renderExpression y)
426−
427−-- | >>> printSQL $ array [null_, notNull false, notNull true]
428−-- ARRAY[NULL, FALSE, TRUE]
429−array
430− :: [Expression schema relations grouping params ('Null ty)]
431− -- ^ array elements
432− -> Expression schema relations grouping params (nullity ('PGvararray ty))
433−array xs = UnsafeExpression $
434− "ARRAY[" <> commaSeparated (renderExpression <$> xs) <> "]"
435
310
436instance (KnownSymbol label, label `In` labels) => IsPGlabel label
311instance (KnownSymbol label, label `In` labels) => IsPGlabel label
437− (Expression schema relations grouping params (nullity ('PGenum labels))) where
312+ (Expression outer commons grp schemas params from (null ('PGenum labels))) where
438− label = UnsafeExpression $ renderLabel (PGlabel @label)
313+ label = UnsafeExpression $ renderSQL (PGlabel @label)
439−
440−-- | A row constructor is an expression that builds a row value
441−-- (also called a composite value) using values for its member fields.
442−--
443−-- >>> type Complex = PGcomposite '["real" ::: 'PGfloat8, "imaginary" ::: 'PGfloat8]
444−-- >>> let i = row (0 `As` #real :* 1 `As` #imaginary :* Nil) :: Expression '[] '[] 'Ungrouped '[] ('NotNull Complex)
445−-- >>> printSQL i
446−-- ROW(0, 1)
447−row
448− :: SListI (Nulls fields)
449− => NP (Aliased (Expression schema relations grouping params)) (Nulls fields)
450− -- ^ zero or more expressions for the row field values
451− -> Expression schema relations grouping params (nullity ('PGcomposite fields))
452−row exprs = UnsafeExpression $ "ROW" <> parenthesized
453− (renderCommaSeparated (\ (expr `As` _) -> renderExpression expr) exprs)
454−
455−instance Has field fields ty => IsLabel field
456− ( Expression schema relation grouping params (nullity ('PGcomposite fields))
457− -> Expression schema relation grouping params ('Null ty) ) where
458− fromLabel expr = UnsafeExpression $
459− parenthesized (renderExpression expr) <> "." <>
460− fromString (symbolVal (Proxy @field))
461−
462−instance Semigroup
463− (Expression schema relations grouping params (nullity ('PGvararray ty))) where
464− (<>) = unsafeBinaryOp "||"
465−
466−instance Monoid
467− (Expression schema relations grouping params (nullity ('PGvararray ty))) where
468− mempty = array []
469− mappend = (<>)
470−
471−-- | >>> let expr = greatest currentTimestamp [param @1] :: Expression sch rels grp '[ 'NotNull 'PGtimestamptz] ('NotNull 'PGtimestamptz)
472−-- >>> printSQL expr
473−-- GREATEST(CURRENT_TIMESTAMP, ($1 :: timestamp with time zone))
474−greatest
475− :: Expression schema relations grouping params (nullty)
476− -- ^ needs at least 1 argument
477− -> [Expression schema relations grouping params (nullty)]
478− -- ^ or more
479− -> Expression schema relations grouping params (nullty)
480−greatest x xs = UnsafeExpression $ "GREATEST("
481− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"
482−
483−-- | >>> printSQL $ least currentTimestamp [null_]
484−-- LEAST(CURRENT_TIMESTAMP, NULL)
485−least
486− :: Expression schema relations grouping params (nullty)
487− -- ^ needs at least 1 argument
488− -> [Expression schema relations grouping params (nullty)]
489− -- ^ or more
490− -> Expression schema relations grouping params (nullty)
491−least x xs = UnsafeExpression $ "LEAST("
492− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"
493
314
494-- | >>> printSQL $ unsafeBinaryOp "OR" true false
315-- | >>> printSQL $ unsafeBinaryOp "OR" true false
495-- (TRUE OR FALSE)
316-- (TRUE OR FALSE)
496−unsafeBinaryOp
317+unsafeBinaryOp :: ByteString -> Operator ty0 ty1 ty2
497− :: ByteString
498− -- ^ operator
499− -> Expression schema relations grouping params (ty0)
500− -> Expression schema relations grouping params (ty1)
501− -> Expression schema relations grouping params (ty2)
502unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $
318unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $
503− renderExpression x <+> op <+> renderExpression y
319+ renderSQL x <+> op <+> renderSQL y
320+
321+binaryOp
322+ :: forall op sch schemas schema x y z.
323+ ( Has sch schemas schema
324+ , Has op schema ('Operator ('BinaryOp x y z)) )
325+ => OperatorDB schemas x y z
326+binaryOp = unsafeBinaryOp $ renderSymbol @op
504
327
505−-- | >>> printSQL $ unsafeUnaryOp "NOT" true
328+-- | >>> printSQL $ unsafeLeftOp "NOT" true
506-- (NOT TRUE)
329-- (NOT TRUE)
507−unsafeUnaryOp
508− :: ByteString
330+unsafeLeftOp :: ByteString -> x --> y
509− -- ^ operator
331+unsafeLeftOp op x = UnsafeExpression $ parenthesized $ op <+> renderSQL x
510− -> Expression schema relations grouping params (ty0)
332+
511− -> Expression schema relations grouping params (ty1)
333+leftOp
334+ :: forall op sch schemas schema x y.
335+ ( Has sch schemas schema
336+ , Has op schema ('Operator ('LeftOp x y)) )
337+ => FunctionDB schemas x y
338+leftOp = unsafeLeftOp $ renderSymbol @op
339+
340+-- | >>> printSQL $ true & unsafeRightOp "IS NOT TRUE"
341+-- (TRUE IS NOT TRUE)
342+unsafeRightOp :: ByteString -> x --> y
512−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $
343+unsafeRightOp op x = UnsafeExpression $ parenthesized $ renderSQL x <+> op
513− op <+> renderExpression x
344+
345+rightOp
346+ :: forall op sch schemas schema x y.
347+ ( Has sch schemas schema
348+ , Has op schema ('Operator ('RightOp x y)) )
349+ => FunctionDB schemas x y
350+rightOp = unsafeRightOp $ renderSymbol @op
514
351
515-- | >>> printSQL $ unsafeFunction "f" true
352-- | >>> printSQL $ unsafeFunction "f" true
516-- f(TRUE)
353-- f(TRUE)
517−unsafeFunction
354+unsafeFunction :: ByteString -> x --> y
518− :: ByteString
519− -- ^ function
520− -> Expression schema relations grouping params (xty)
521− -> Expression schema relations grouping params (yty)
522unsafeFunction fun x = UnsafeExpression $
355unsafeFunction fun x = UnsafeExpression $
523− fun <> parenthesized (renderExpression x)
356+ fun <> parenthesized (renderSQL x)
524−
357+
525−unsafeVariadicFunction
358+function
526− :: SListI elems
359+ :: (Has sch schemas schema, Has fun schema ('Function ('[x] :=> 'Returns y)))
360+ => QualifiedAlias sch fun
361+ -> FunctionDB schemas x y
362+function = unsafeFunction . renderSQL
363+
364+-- | >>> printSQL $ unsafeFunctionN "f" (currentTime :* localTimestamp :* false *: literal 'a')
365+-- f(CURRENT_TIME, LOCALTIMESTAMP, FALSE, E'a')
527− => ByteString
366+unsafeFunctionN :: SListI xs => ByteString -> xs ---> y
528− -- ^ function
529− -> NP (Expression schema relations grouping params) elems
530− -> Expression schema relations grouping params ret
531−unsafeVariadicFunction fun x = UnsafeExpression $
367+unsafeFunctionN fun xs = UnsafeExpression $
532− fun <> parenthesized (commaSeparated (hcollapse (hmap (K . renderExpression) x)))
368+ fun <> parenthesized (renderCommaSeparated renderSQL xs)
533−
369+
370+functionN
371+ :: ( Has sch schemas schema
372+ , Has fun schema ('Function (xs :=> 'Returns y))
373+ , SListI xs )
374+ => QualifiedAlias sch fun
375+ -> FunctionNDB schemas xs y
376+functionN = unsafeFunctionN . renderSQL
377+
534−instance PGNum ty
378+instance ty `In` PGNum
535− => Num (Expression schema relations grouping params (nullity ty)) where
379+ => Num (Expression outer commons grp schemas params from (null ty)) where
536 (+) = unsafeBinaryOp "+"
380 (+) = unsafeBinaryOp "+"
537 (-) = unsafeBinaryOp "-"
381 (-) = unsafeBinaryOp "-"
538 (*) = unsafeBinaryOp "*"
382 (*) = unsafeBinaryOp "*"
@@ -543,19 +387,24 @@ instance PGNum ty
543 . fromString
387 . fromString
544 . show
388 . show
545
389
546−instance (PGNum ty, PGFloating ty) => Fractional
390+instance (ty `In` PGNum, ty `In` PGFloating) => Fractional
547− (Expression schema relations grouping params (nullity ty)) where
391+ (Expression outer commons grp schemas params from (null ty)) where
548 (/) = unsafeBinaryOp "/"
392 (/) = unsafeBinaryOp "/"
549− fromRational x = fromInteger (numerator x) / fromInteger (denominator x)
393+ fromRational
394+ = UnsafeExpression
395+ . fromString
396+ . ($ "")
397+ . showFFloat Nothing
398+ . fromRat @Double
550
399
551−instance (PGNum ty, PGFloating ty) => Floating
400+instance (ty `In` PGNum, ty `In` PGFloating) => Floating
552− (Expression schema relations grouping params (nullity ty)) where
401+ (Expression outer commons grp schemas params from (null ty)) where
553 pi = UnsafeExpression "pi()"
402 pi = UnsafeExpression "pi()"
554 exp = unsafeFunction "exp"
403 exp = unsafeFunction "exp"
555 log = unsafeFunction "ln"
404 log = unsafeFunction "ln"
556 sqrt = unsafeFunction "sqrt"
405 sqrt = unsafeFunction "sqrt"
557 b ** x = UnsafeExpression $
406 b ** x = UnsafeExpression $
558− "power(" <> renderExpression b <> ", " <> renderExpression x <> ")"
407+ "power(" <> renderSQL b <> ", " <> renderSQL x <> ")"
559 logBase b y = log y / log b
408 logBase b y = log y / log b
560 sin = unsafeFunction "sin"
409 sin = unsafeFunction "sin"
561 cos = unsafeFunction "cos"
410 cos = unsafeFunction "cos"
@@ -570,1049 +419,54 @@ instance (PGNum ty, PGFloating ty) => Floating
570 acosh x = log (x + sqrt (x*x - 1))
419 acosh x = log (x + sqrt (x*x - 1))
571 atanh x = log ((1 + x) / (1 - x)) / 2
420 atanh x = log ((1 + x) / (1 - x)) / 2
572
421
573−-- | >>> :{
422+-- | Contained by operators
574−-- let
423+class PGSubset ty where
575−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)
424+ (@>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
576−-- expression = atan2_ pi 2
425+ (@>) = unsafeBinaryOp "@>"
577−-- in printSQL expression
426+ (<@) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
578−-- :}
427+ (<@) = unsafeBinaryOp "<@"
579−-- atan2(pi(), 2)
428+instance PGSubset 'PGjsonb
580−atan2_
429+instance PGSubset 'PGtsquery
581− :: PGFloating float
430+instance PGSubset ('PGvararray ty)
582− => Expression schema relations grouping params (nullity float)
431+instance PGSubset ('PGrange ty)
583− -- ^ numerator
432+
584− -> Expression schema relations grouping params (nullity float)
433+class PGIntersect ty where
585− -- ^ denominator
434+ (@&&) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
586− -> Expression schema relations grouping params (nullity float)
435+ (@&&) = unsafeBinaryOp "&&"
587−atan2_ y x = UnsafeExpression $
436+instance PGIntersect ('PGvararray ty)
588− "atan2(" <> renderExpression y <> ", " <> renderExpression x <> ")"
437+instance PGIntersect ('PGrange ty)
589−
590−-- When a `cast` is applied to an `Expression` of a known type, it
591−-- represents a run-time type conversion. The cast will succeed only if a
592−-- suitable type conversion operation has been defined.
593−--
594−-- | >>> printSQL $ true & cast int4
595−-- (TRUE :: int4)
596−cast
597− :: TypeExpression schema ty1
598− -- ^ type to cast as
599− -> Expression schema relations grouping params (nullity ty0)
600− -- ^ value to convert
601− -> Expression schema relations grouping params (nullity ty1)
602−cast ty x = UnsafeExpression $ parenthesized $
603− renderExpression x <+> "::" <+> renderTypeExpression ty
604−
605−-- | integer division, truncates the result
606−--
607−-- >>> :{
608−-- let
609−-- expression :: Expression schema relations grouping params (nullity 'PGint2)
610−-- expression = 5 `quot_` 2
611−-- in printSQL expression
612−-- :}
613−-- (5 / 2)
614−quot_
615− :: PGIntegral int
616− => Expression schema relations grouping params (nullity int)
617− -- ^ numerator
618− -> Expression schema relations grouping params (nullity int)
619− -- ^ denominator
620− -> Expression schema relations grouping params (nullity int)
621−quot_ = unsafeBinaryOp "/"
622−
623−-- | remainder upon integer division
624−--
625−-- >>> :{
626−-- let
627−-- expression :: Expression schema relations grouping params (nullity 'PGint2)
628−-- expression = 5 `rem_` 2
629−-- in printSQL expression
630−-- :}
631−-- (5 % 2)
632−rem_
633− :: PGIntegral int
634− => Expression schema relations grouping params (nullity int)
635− -- ^ numerator
636− -> Expression schema relations grouping params (nullity int)
637− -- ^ denominator
638− -> Expression schema relations grouping params (nullity int)
639−rem_ = unsafeBinaryOp "%"
640−
641−-- | >>> :{
642−-- let
643−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)
644−-- expression = trunc pi
645−-- in printSQL expression
646−-- :}
647−-- trunc(pi())
648−trunc
649− :: PGFloating frac
650− => Expression schema relations grouping params (nullity frac)
651− -- ^ fractional number
652− -> Expression schema relations grouping params (nullity frac)
653−trunc = unsafeFunction "trunc"
654−
655−-- | >>> :{
656−-- let
657−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)
658−-- expression = round_ pi
659−-- in printSQL expression
660−-- :}
661−-- round(pi())
662−round_
663− :: PGFloating frac
664− => Expression schema relations grouping params (nullity frac)
665− -- ^ fractional number
666− -> Expression schema relations grouping params (nullity frac)
667−round_ = unsafeFunction "round"
668−
669−-- | >>> :{
670−-- let
671−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)
672−-- expression = ceiling_ pi
673−-- in printSQL expression
674−-- :}
675−-- ceiling(pi())
676−ceiling_
677− :: PGFloating frac
678− => Expression schema relations grouping params (nullity frac)
679− -- ^ fractional number
680− -> Expression schema relations grouping params (nullity frac)
681−ceiling_ = unsafeFunction "ceiling"
682−
683−-- | A `Condition` is a boolean valued `Expression`. While SQL allows
684−-- conditions to have @NULL@, Squeal instead chooses to disallow @NULL@,
685−-- forcing one to handle the case of @NULL@ explicitly to produce
686−-- a `Condition`.
687−type Condition schema relations grouping params =
688− Expression schema relations grouping params ('NotNull 'PGbool)
689−
690−-- | >>> printSQL true
691−-- TRUE
692−true :: Condition schema relations grouping params
693−true = UnsafeExpression "TRUE"
694−
695−-- | >>> printSQL false
696−-- FALSE
697−false :: Condition schema relations grouping params
698−false = UnsafeExpression "FALSE"
699−
700−-- | >>> printSQL $ not_ true
701−-- (NOT TRUE)
702−not_
703− :: Condition schema relations grouping params
704− -> Condition schema relations grouping params
705−not_ = unsafeUnaryOp "NOT"
706−
707−-- | >>> printSQL $ true .&& false
708−-- (TRUE AND FALSE)
709−(.&&)
710− :: Condition schema relations grouping params
711− -> Condition schema relations grouping params
712− -> Condition schema relations grouping params
713−(.&&) = unsafeBinaryOp "AND"
714−
715−-- | >>> printSQL $ true .|| false
716−-- (TRUE OR FALSE)
717−(.||)
718− :: Condition schema relations grouping params
719− -> Condition schema relations grouping params
720− -> Condition schema relations grouping params
721−(.||) = unsafeBinaryOp "OR"
722−
723−-- | >>> :{
724−-- let
725−-- expression :: Expression schema relations grouping params (nullity 'PGint2)
726−-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3
727−-- in printSQL expression
728−-- :}
729−-- CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END
730−caseWhenThenElse
731− :: [ ( Condition schema relations grouping params
732− , Expression schema relations grouping params (ty)
733− ) ]
734− -- ^ whens and thens
735− -> Expression schema relations grouping params (ty)
736− -- ^ else
737− -> Expression schema relations grouping params (ty)
738−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat
739− [ "CASE"
740− , mconcat
741− [ mconcat
742− [ " WHEN ", renderExpression when_
743− , " THEN ", renderExpression then_
744− ]
745− | (when_,then_) <- whenThens
746− ]
747− , " ELSE ", renderExpression else_
748− , " END"
749− ]
750−
751−-- | >>> :{
752−-- let
753−-- expression :: Expression schema relations grouping params (nullity 'PGint2)
754−-- expression = ifThenElse true 1 0
755−-- in printSQL expression
756−-- :}
757−-- CASE WHEN TRUE THEN 1 ELSE 0 END
758−ifThenElse
759− :: Condition schema relations grouping params
760− -> Expression schema relations grouping params (ty) -- ^ then
761− -> Expression schema relations grouping params (ty) -- ^ else
762− -> Expression schema relations grouping params (ty)
763−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_
764−
765−-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`
766−-- will produce @NULL@s if one of their arguments is @NULL@.
767−--
768−-- >>> printSQL $ notNull true .== null_
769−-- (TRUE = NULL)
770−(.==)
771− :: Expression schema relations grouping params (nullity ty) -- ^ lhs
772− -> Expression schema relations grouping params (nullity ty) -- ^ rhs
773− -> Expression schema relations grouping params (nullity 'PGbool)
774−(.==) = unsafeBinaryOp "="
775−infix 4 .==
776−
777−-- | >>> printSQL $ notNull true ./= null_
778−-- (TRUE <> NULL)
779−(./=)
780− :: Expression schema relations grouping params (nullity ty) -- ^ lhs
781− -> Expression schema relations grouping params (nullity ty) -- ^ rhs
782− -> Expression schema relations grouping params (nullity 'PGbool)
783−(./=) = unsafeBinaryOp "<>"
784−infix 4 ./=
785−
786−-- | >>> printSQL $ notNull true .>= null_
787−-- (TRUE >= NULL)
788−(.>=)
789− :: Expression schema relations grouping params (nullity ty) -- ^ lhs
790− -> Expression schema relations grouping params (nullity ty) -- ^ rhs
791− -> Expression schema relations grouping params (nullity 'PGbool)
792−(.>=) = unsafeBinaryOp ">="
793−infix 4 .>=
794−
795−-- | >>> printSQL $ notNull true .< null_
796−-- (TRUE < NULL)
797−(.<)
798− :: Expression schema relations grouping params (nullity ty) -- ^ lhs
799− -> Expression schema relations grouping params (nullity ty) -- ^ rhs
800− -> Expression schema relations grouping params (nullity 'PGbool)
801−(.<) = unsafeBinaryOp "<"
802−infix 4 .<
803−
804−-- | >>> printSQL $ notNull true .<= null_
805−-- (TRUE <= NULL)
806−(.<=)
807− :: Expression schema relations grouping params (nullity ty) -- ^ lhs
808− -> Expression schema relations grouping params (nullity ty) -- ^ rhs
809− -> Expression schema relations grouping params (nullity 'PGbool)
810−(.<=) = unsafeBinaryOp "<="
811−infix 4 .<=
812−
813−-- | >>> printSQL $ notNull true .> null_
814−-- (TRUE > NULL)
815−(.>)
816− :: Expression schema relations grouping params (nullity ty) -- ^ lhs
817− -> Expression schema relations grouping params (nullity ty) -- ^ rhs
818− -> Expression schema relations grouping params (nullity 'PGbool)
819−(.>) = unsafeBinaryOp ">"
820−infix 4 .>
821−
822−-- | >>> printSQL currentDate
823−-- CURRENT_DATE
824−currentDate
825− :: Expression schema relations grouping params (nullity 'PGdate)
826−currentDate = UnsafeExpression "CURRENT_DATE"
827−
828−-- | >>> printSQL currentTime
829−-- CURRENT_TIME
830−currentTime
831− :: Expression schema relations grouping params (nullity 'PGtimetz)
832−currentTime = UnsafeExpression "CURRENT_TIME"
833−
834−-- | >>> printSQL currentTimestamp
835−-- CURRENT_TIMESTAMP
836−currentTimestamp
837− :: Expression schema relations grouping params (nullity 'PGtimestamptz)
838−currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"
839−
840−-- | >>> printSQL localTime
841−-- LOCALTIME
842−localTime
843− :: Expression schema relations grouping params (nullity 'PGtime)
844−localTime = UnsafeExpression "LOCALTIME"
845−
846−-- | >>> printSQL localTimestamp
847−-- LOCALTIMESTAMP
848−localTimestamp
849− :: Expression schema relations grouping params (nullity 'PGtimestamp)
850−localTimestamp = UnsafeExpression "LOCALTIMESTAMP"
851−
852−{-----------------------------------------
853−text
854−-----------------------------------------}
855
438
856instance IsString
439instance IsString
857− (Expression schema relations grouping params (nullity 'PGtext)) where
440+ (Expression outer commons grp schemas params from (null 'PGtext)) where
858 fromString str = UnsafeExpression $
441 fromString str = UnsafeExpression $
859 "E\'" <> fromString (escape =<< str) <> "\'"
442 "E\'" <> fromString (escape =<< str) <> "\'"
860− where
443+instance IsString
861− escape = \case
444+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where
862− '\NUL' -> "\\0"
445+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsvector") $
863− '\'' -> "''"
446+ "E\'" <> fromString (escape =<< str) <> "\'"
864− '"' -> "\\\""
447+instance IsString
865− '\b' -> "\\b"
448+ (Expression outer commons grp schemas params from (null 'PGtsquery)) where
866− '\n' -> "\\n"
449+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsquery") $
867− '\r' -> "\\r"
450+ "E\'" <> fromString (escape =<< str) <> "\'"
868− '\t' -> "\\t"
869− '\\' -> "\\\\"
870− c -> [c]
871
451
872instance Semigroup
452instance Semigroup
873− (Expression schema relations grouping params (nullity 'PGtext)) where
453+ (Expression outer commons grp schemas params from (null ('PGvararray ty))) where
454+ (<>) = unsafeBinaryOp "||"
455+instance Semigroup
456+ (Expression outer commons grp schemas params from (null 'PGjsonb)) where
457+ (<>) = unsafeBinaryOp "||"
458+instance Semigroup
459+ (Expression outer commons grp schemas params from (null 'PGtext)) where
460+ (<>) = unsafeBinaryOp "||"
461+instance Semigroup
462+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where
874 (<>) = unsafeBinaryOp "||"
463 (<>) = unsafeBinaryOp "||"
875
464
876instance Monoid
465instance Monoid
877− (Expression schema relations grouping params (nullity 'PGtext)) where
466+ (Expression outer commons grp schemas params from (null 'PGtext)) where
467+ mempty = fromString ""
468+ mappend = (<>)
469+instance Monoid
470+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where
878 mempty = fromString ""
471 mempty = fromString ""
879 mappend = (<>)
472 mappend = (<>)
880−
881−-- | >>> printSQL $ lower "ARRRGGG"
882−-- lower(E'ARRRGGG')
883−lower
884− :: Expression schema relations grouping params (nullity 'PGtext)
885− -- ^ string to lower case
886− -> Expression schema relations grouping params (nullity 'PGtext)
887−lower = unsafeFunction "lower"
888−
889−-- | >>> printSQL $ upper "eeee"
890−-- upper(E'eeee')
891−upper
892− :: Expression schema relations grouping params (nullity 'PGtext)
893− -- ^ string to upper case
894− -> Expression schema relations grouping params (nullity 'PGtext)
895−upper = unsafeFunction "upper"
896−
897−-- | >>> printSQL $ charLength "four"
898−-- char_length(E'four')
899−charLength
900− :: Expression schema relations grouping params (nullity 'PGtext)
901− -- ^ string to measure
902− -> Expression schema relations grouping params (nullity 'PGint4)
903−charLength = unsafeFunction "char_length"
904−
905−-- | The `like` expression returns true if the @string@ matches
906−-- the supplied @pattern@. If @pattern@ does not contain percent signs
907−-- or underscores, then the pattern only represents the string itself;
908−-- in that case `like` acts like the equals operator. An underscore (_)
909−-- in pattern stands for (matches) any single character; a percent sign (%)
910−-- matches any sequence of zero or more characters.
911−--
912−-- >>> printSQL $ "abc" `like` "a%"
913−-- (E'abc' LIKE E'a%')
914−like
915− :: Expression schema relations grouping params (nullity 'PGtext)
916− -- ^ string
917− -> Expression schema relations grouping params (nullity 'PGtext)
918− -- ^ pattern
919− -> Expression schema relations grouping params (nullity 'PGbool)
920−like = unsafeBinaryOp "LIKE"
921−
922−{-----------------------------------------
923− -- json and jsonb support
924−
925−See https://www.postgresql.org/docs/10/static/functions-json.html -- most
926−comments lifted directly from this page.
927−
928−Table 9.44: json and jsonb operators
929−-----------------------------------------}
930−
931−-- | Get JSON value (object field or array element) at a key.
932−(.->)
933− :: (PGjson_ json, PGjsonKey key)
934− => Expression schema relations grouping params (nullity json)
935− -> Expression schema relations grouping params (nullity key)
936− -> Expression schema relations grouping params ('Null json)
937−(.->) = unsafeBinaryOp "->"
938−
939−-- | Get JSON value (object field or array element) at a key, as text.
940−(.->>)
941− :: (PGjson_ json, PGjsonKey key)
942− => Expression schema relations grouping params (nullity json)
943− -> Expression schema relations grouping params (nullity key)
944− -> Expression schema relations grouping params ('Null 'PGtext)
945−(.->>) = unsafeBinaryOp "->>"
946−
947−-- | Get JSON value at a specified path.
948−(.#>)
949− :: (PGjson_ json, PGtextArray "(.#>)" path)
950− => Expression schema relations grouping params (nullity json)
951− -> Expression schema relations grouping params (nullity path)
952− -> Expression schema relations grouping params ('Null json)
953−(.#>) = unsafeBinaryOp "#>"
954−
955−-- | Get JSON value at a specified path as text.
956−(.#>>)
957− :: (PGjson_ json, PGtextArray "(.#>>)" path)
958− => Expression schema relations grouping params (nullity json)
959− -> Expression schema relations grouping params (nullity path)
960− -> Expression schema relations grouping params ('Null 'PGtext)
961−(.#>>) = unsafeBinaryOp "#>>"
962−
963−-- Additional jsonb operators
964−
965−-- | Does the left JSON value contain the right JSON path/value entries at the
966−-- top level?
967−(.@>)
968− :: Expression schema relations grouping params (nullity 'PGjsonb)
969− -> Expression schema relations grouping params (nullity 'PGjsonb)
970− -> Expression schema relations grouping params ('NotNull 'PGbool)
971−(.@>) = unsafeBinaryOp "@>"
972−
973−-- | Are the left JSON path/value entries contained at the top level within the
974−-- right JSON value?
975−(.<@)
976− :: Expression schema relations grouping params (nullity 'PGjsonb)
977− -> Expression schema relations grouping params (nullity 'PGjsonb)
978− -> Expression schema relations grouping params ('NotNull 'PGbool)
979−(.<@) = unsafeBinaryOp "<@"
980−
981−-- | Does the string exist as a top-level key within the JSON value?
982−(.?)
983− :: Expression schema relations grouping params (nullity 'PGjsonb)
984− -> Expression schema relations grouping params (nullity 'PGtext)
985− -> Expression schema relations grouping params ('NotNull 'PGbool)
986−(.?) = unsafeBinaryOp "?"
987−
988−-- | Do any of these array strings exist as top-level keys?
989−(.?|)
990− :: Expression schema relations grouping params (nullity 'PGjsonb)
991− -> Expression schema relations grouping params (nullity ('PGvararray 'PGtext))
992− -> Expression schema relations grouping params ('NotNull 'PGbool)
993−(.?|) = unsafeBinaryOp "?|"
994−
995−-- | Do all of these array strings exist as top-level keys?
996−(.?&)
997− :: Expression schema relations grouping params (nullity 'PGjsonb)
998− -> Expression schema relations grouping params (nullity ('PGvararray 'PGtext))
999− -> Expression schema relations grouping params ('NotNull 'PGbool)
1000−(.?&) = unsafeBinaryOp "?&"
1001−
1002−-- | Concatenate two jsonb values into a new jsonb value.
1003−(.||.)
1004− :: Expression schema relations grouping params (nullity 'PGjsonb)
1005− -> Expression schema relations grouping params (nullity 'PGjsonb)
1006− -> Expression schema relations grouping params (nullity 'PGjsonb)
1007−(.||.) = unsafeBinaryOp "||"
1008−
1009−-- | Delete a key or keys from a JSON object, or remove an array element.
1010−--
1011−-- If the right operand is..
1012−--
1013−-- @ text @: Delete key/value pair or string element from left operand. Key/value pairs
1014−-- are matched based on their key value.
1015−--
1016−-- @ text[] @: Delete multiple key/value pairs or string elements
1017−-- from left operand. Key/value pairs are matched based on their key value.
1018−--
1019−-- @ integer @: Delete the array element with specified index (Negative integers
1020−-- count from the end). Throws an error if top level container is not an array.
1021−(.-.)
1022− :: (key `In` '[ 'PGtext, 'PGvararray 'PGtext, 'PGint4, 'PGint2 ]) -- hlint error without parens here
1023− => Expression schema relations grouping params (nullity 'PGjsonb)
1024− -> Expression schema relations grouping params (nullity key)
1025− -> Expression schema relations grouping params (nullity 'PGjsonb)
1026−(.-.) = unsafeBinaryOp "-"
1027−
1028−-- | Delete the field or element with specified path (for JSON arrays, negative
1029−-- integers count from the end)
1030−(#-.)
1031− :: PGtextArray "(#-.)" arrayty
1032− => Expression schema relations grouping params (nullity 'PGjsonb)
1033− -> Expression schema relations grouping params (nullity arrayty)
1034− -> Expression schema relations grouping params (nullity 'PGjsonb)
1035−(#-.) = unsafeBinaryOp "#-"
1036−
1037−{-----------------------------------------
1038−Table 9.45: JSON creation functions
1039−-----------------------------------------}
1040−
1041−-- | Returns the value as json. Arrays and composites are converted
1042−-- (recursively) to arrays and objects; otherwise, if there is a cast from the
1043−-- type to json, the cast function will be used to perform the conversion;
1044−-- otherwise, a scalar value is produced. For any scalar type other than a
1045−-- number, a Boolean, or a null value, the text representation will be used, in
1046−-- such a fashion that it is a valid json value.
1047−toJson
1048− :: Expression schema relations grouping params (nullity ty)
1049− -> Expression schema relations grouping params (nullity 'PGjson)
1050−toJson = unsafeFunction "to_json"
1051−
1052−-- | Returns the value as jsonb. Arrays and composites are converted
1053−-- (recursively) to arrays and objects; otherwise, if there is a cast from the
1054−-- type to json, the cast function will be used to perform the conversion;
1055−-- otherwise, a scalar value is produced. For any scalar type other than a
1056−-- number, a Boolean, or a null value, the text representation will be used, in
1057−-- such a fashion that it is a valid jsonb value.
1058−toJsonb
1059− :: Expression schema relations grouping params (nullity ty)
1060− -> Expression schema relations grouping params (nullity 'PGjsonb)
1061−toJsonb = unsafeUnaryOp "to_jsonb"
1062−
1063−-- | Returns the array as a JSON array. A PostgreSQL multidimensional array
1064−-- becomes a JSON array of arrays. Line feeds will be added between dimension-1
1065−-- elements if pretty_bool is true.
1066−arrayToJson
1067− :: PGarray "arrayToJson" arr
1068− => Expression schema relations grouping params (nullity arr)
1069− -> Expression schema relations grouping params (nullity 'PGjson)
1070−arrayToJson = unsafeFunction "array_to_json"
1071−
1072−-- | Returns the row as a JSON object. Line feeds will be added between level-1
1073−-- elements if pretty_bool is true.
1074−rowToJson
1075− :: Expression schema relations grouping params (nullity ('PGcomposite ty))
1076− -> Expression schema relations grouping params (nullity 'PGjson)
1077−rowToJson = unsafeFunction "row_to_json"
1078−
1079−-- | Builds a possibly-heterogeneously-typed JSON array out of a variadic
1080−-- argument list.
1081−jsonBuildArray
1082− :: SListI elems
1083− => NP (Expression schema relations grouping params) elems
1084− -> Expression schema relations grouping params (nullity 'PGjson)
1085−jsonBuildArray = unsafeVariadicFunction "json_build_array"
1086−
1087−-- | Builds a possibly-heterogeneously-typed (binary) JSON array out of a
1088−-- variadic argument list.
1089−jsonbBuildArray
1090− :: SListI elems
1091− => NP (Expression schema relations grouping params) elems
1092− -> Expression schema relations grouping params (nullity 'PGjsonb)
1093−jsonbBuildArray = unsafeVariadicFunction "jsonb_build_array"
1094−
1095−-- | Builds a possibly-heterogeneously-typed JSON object out of a variadic
1096−-- argument list. The elements of the argument list must alternate between text
1097−-- and values.
1098−jsonBuildObject
1099− :: (PGobjectpairs "jsonBuildObject" elems, SListI elems)
1100− => NP (Expression schema relations grouping params) elems
1101− -> Expression schema relations grouping params (nullity 'PGjson)
1102−jsonBuildObject = unsafeVariadicFunction "json_build_object"
1103−
1104−-- | Builds a possibly-heterogeneously-typed (binary) JSON object out of a
1105−-- variadic argument list. The elements of the argument list must alternate
1106−-- between text and values.
1107−jsonbBuildObject
1108− :: (PGobjectpairs "jsonbBuildObject" elems, SListI elems)
1109− => NP (Expression schema relations grouping params) elems
1110− -> Expression schema relations grouping params (nullity 'PGjsonb)
1111−jsonbBuildObject = unsafeVariadicFunction "jsonb_build_object"
1112−
1113−-- | Builds a JSON object out of a text array. The array must have either
1114−-- exactly one dimension with an even number of members, in which case they are
1115−-- taken as alternating key/value pairs, or two dimensions such that each inner
1116−-- array has exactly two elements, which are taken as a key/value pair.
1117−jsonObject
1118− :: PGarrayOf "jsonObject" arr 'PGtext
1119− => Expression schema relations grouping params (nullity arr)
1120− -> Expression schema relations grouping params (nullity 'PGjson)
1121−jsonObject = unsafeFunction "json_object"
1122−
1123−-- | Builds a binary JSON object out of a text array. The array must have either
1124−-- exactly one dimension with an even number of members, in which case they are
1125−-- taken as alternating key/value pairs, or two dimensions such that each inner
1126−-- array has exactly two elements, which are taken as a key/value pair.
1127−jsonbObject
1128− :: PGarrayOf "jsonbObject" arr 'PGtext
1129− => Expression schema relations grouping params (nullity arr)
1130− -> Expression schema relations grouping params (nullity 'PGjsonb)
1131−jsonbObject = unsafeFunction "jsonb_object"
1132−
1133−-- | This is an alternate form of 'jsonObject' that takes two arrays; one for
1134−-- keys and one for values, that are zipped pairwise to create a JSON object.
1135−jsonZipObject
1136− :: ( PGarrayOf "jsonZipObject" keysArray 'PGtext
1137− , PGarrayOf "jsonZipObject" valuesArray 'PGtext)
1138− => Expression schema relations grouping params (nullity keysArray)
1139− -> Expression schema relations grouping params (nullity valuesArray)
1140− -> Expression schema relations grouping params (nullity 'PGjson)
1141−jsonZipObject ks vs =
1142− unsafeVariadicFunction "json_object" (ks :* vs :* Nil)
1143−
1144−-- | This is an alternate form of 'jsonObject' that takes two arrays; one for
1145−-- keys and one for values, that are zipped pairwise to create a binary JSON
1146−-- object.
1147−jsonbZipObject
1148− :: ( PGarrayOf "jsonbZipObject" keysArray 'PGtext
1149− , PGarrayOf "jsonbZipObject" valuesArray 'PGtext)
1150− => Expression schema relations grouping params (nullity keysArray)
1151− -> Expression schema relations grouping params (nullity valuesArray)
1152− -> Expression schema relations grouping params (nullity 'PGjsonb)
1153−jsonbZipObject ks vs =
1154− unsafeVariadicFunction "jsonb_object" (ks :* vs :* Nil)
1155−
1156−{-----------------------------------------
1157−Table 9.46: JSON processing functions
1158−-----------------------------------------}
1159−
1160−-- | Returns the number of elements in the outermost JSON array.
1161−jsonArrayLength
1162− :: Expression schema relations grouping params (nullity 'PGjson)
1163− -> Expression schema relations grouping params (nullity 'PGint4)
1164−jsonArrayLength = unsafeFunction "json_array_length"
1165−
1166−-- | Returns the number of elements in the outermost binary JSON array.
1167−jsonbArrayLength
1168− :: Expression schema relations grouping params (nullity 'PGjsonb)
1169− -> Expression schema relations grouping params (nullity 'PGint4)
1170−jsonbArrayLength = unsafeFunction "jsonb_array_length"
1171−
1172−-- | Returns JSON value pointed to by path_elems (equivalent to #> operator).
1173−jsonExtractPath
1174− :: SListI elems
1175− => Expression schema relations grouping params (nullity 'PGjson)
1176− -> NP (Expression schema relations grouping params) elems
1177− -> Expression schema relations grouping params (nullity 'PGjsonb)
1178−jsonExtractPath x xs =
1179− unsafeVariadicFunction "json_extract_path" (x :* xs)
1180−
1181−-- | Returns JSON value pointed to by path_elems (equivalent to #> operator).
1182−jsonbExtractPath
1183− :: SListI elems
1184− => Expression schema relations grouping params (nullity 'PGjsonb)
1185− -> NP (Expression schema relations grouping params) elems
1186− -> Expression schema relations grouping params (nullity 'PGjsonb)
1187−jsonbExtractPath x xs =
1188− unsafeVariadicFunction "jsonb_extract_path" (x :* xs)
1189−
1190−-- | Returns JSON value pointed to by path_elems (equivalent to #> operator),
1191−-- as text.
1192−jsonExtractPathAsText
1193− :: SListI elems
1194− => Expression schema relations grouping params (nullity 'PGjson)
1195− -> NP (Expression schema relations grouping params) elems
1196− -> Expression schema relations grouping params (nullity 'PGjsonb)
1197−jsonExtractPathAsText x xs =
1198− unsafeVariadicFunction "json_extract_path_text" (x :* xs)
1199−
1200−-- | Returns JSON value pointed to by path_elems (equivalent to #> operator),
1201−-- as text.
1202−jsonbExtractPathAsText
1203− :: SListI elems
1204− => Expression schema relations grouping params (nullity 'PGjsonb)
1205− -> NP (Expression schema relations grouping params) elems
1206− -> Expression schema relations grouping params (nullity 'PGjsonb)
1207−jsonbExtractPathAsText x xs =
1208− unsafeVariadicFunction "jsonb_extract_path_text" (x :* xs)
1209−
1210−-- | Returns set of keys in the outermost JSON object.
1211−jsonObjectKeys
1212− :: Expression schema relations grouping params (nullity 'PGjson)
1213− -> Expression schema relations grouping params (nullity 'PGtext)
1214−jsonObjectKeys = unsafeFunction "json_object_keys"
1215−
1216−-- | Returns set of keys in the outermost JSON object.
1217−jsonbObjectKeys
1218− :: Expression schema relations grouping params (nullity 'PGjsonb)
1219− -> Expression schema relations grouping params (nullity 'PGtext)
1220−jsonbObjectKeys = unsafeFunction "jsonb_object_keys"
1221−
1222−-- | Returns the type of the outermost JSON value as a text string. Possible
1223−-- types are object, array, string, number, boolean, and null.
1224−jsonTypeof
1225− :: Expression schema relations grouping params (nullity 'PGjson)
1226− -> Expression schema relations grouping params (nullity 'PGtext)
1227−jsonTypeof = unsafeFunction "json_typeof"
1228−
1229−-- | Returns the type of the outermost binary JSON value as a text string.
1230−-- Possible types are object, array, string, number, boolean, and null.
1231−jsonbTypeof
1232− :: Expression schema relations grouping params (nullity 'PGjsonb)
1233− -> Expression schema relations grouping params (nullity 'PGtext)
1234−jsonbTypeof = unsafeFunction "jsonb_typeof"
1235−
1236−{-----------------------------------------
1237−aggregation
1238−-----------------------------------------}
1239−
1240−-- | escape hatch to define aggregate functions
1241−unsafeAggregate
1242− :: ByteString -- ^ aggregate function
1243− -> Expression schema relations 'Ungrouped params (xty)
1244− -> Expression schema relations ('Grouped bys) params (yty)
1245−unsafeAggregate fun x = UnsafeExpression $ mconcat
1246− [fun, "(", renderExpression x, ")"]
1247−
1248−-- | escape hatch to define aggregate functions over distinct values
1249−unsafeAggregateDistinct
1250− :: ByteString -- ^ aggregate function
1251− -> Expression schema relations 'Ungrouped params (xty)
1252− -> Expression schema relations ('Grouped bys) params (yty)
1253−unsafeAggregateDistinct fun x = UnsafeExpression $ mconcat
1254− [fun, "(DISTINCT ", renderExpression x, ")"]
1255−
1256−-- | >>> :{
1257−-- let
1258−-- expression :: Expression schema '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Grouped bys) params ('Null 'PGnumeric)
1259−-- expression = sum_ #col
1260−-- in printSQL expression
1261−-- :}
1262−-- sum("col")
1263−sum_
1264− :: PGNum ty
1265− => Expression schema relations 'Ungrouped params (nullity ty)
1266− -- ^ what to sum
1267− -> Expression schema relations ('Grouped bys) params (nullity ty)
1268−sum_ = unsafeAggregate "sum"
1269−
1270−-- | >>> :{
1271−-- let
1272−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGnumeric]] ('Grouped bys) params (nullity 'PGnumeric)
1273−-- expression = sumDistinct #col
1274−-- in printSQL expression
1275−-- :}
1276−-- sum(DISTINCT "col")
1277−sumDistinct
1278− :: PGNum ty
1279− => Expression schema relations 'Ungrouped params (nullity ty)
1280− -- ^ what to sum
1281− -> Expression schema relations ('Grouped bys) params (nullity ty)
1282−sumDistinct = unsafeAggregateDistinct "sum"
1283−
1284−-- | A constraint for `PGType`s that you can take averages of and the resulting
1285−-- `PGType`.
1286−class PGAvg ty avg | ty -> avg where
1287− avg, avgDistinct
1288− :: Expression schema relations 'Ungrouped params (nullity ty)
1289− -- ^ what to average
1290− -> Expression schema relations ('Grouped bys) params (nullity avg)
1291− avg = unsafeAggregate "avg"
1292− avgDistinct = unsafeAggregateDistinct "avg"
1293−instance PGAvg 'PGint2 'PGnumeric
1294−instance PGAvg 'PGint4 'PGnumeric
1295−instance PGAvg 'PGint8 'PGnumeric
1296−instance PGAvg 'PGnumeric 'PGnumeric
1297−instance PGAvg 'PGfloat4 'PGfloat8
1298−instance PGAvg 'PGfloat8 'PGfloat8
1299−instance PGAvg 'PGinterval 'PGinterval
1300−
1301−-- | >>> :{
1302−-- let
1303−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
1304−-- expression = bitAnd #col
1305−-- in printSQL expression
1306−-- :}
1307−-- bit_and("col")
1308−bitAnd
1309− :: PGIntegral int
1310− => Expression schema relations 'Ungrouped params (nullity int)
1311− -- ^ what to aggregate
1312− -> Expression schema relations ('Grouped bys) params (nullity int)
1313−bitAnd = unsafeAggregate "bit_and"
1314−
1315−-- | >>> :{
1316−-- let
1317−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
1318−-- expression = bitOr #col
1319−-- in printSQL expression
1320−-- :}
1321−-- bit_or("col")
1322−bitOr
1323− :: PGIntegral int
1324− => Expression schema relations 'Ungrouped params (nullity int)
1325− -- ^ what to aggregate
1326− -> Expression schema relations ('Grouped bys) params (nullity int)
1327−bitOr = unsafeAggregate "bit_or"
1328−
1329−-- | >>> :{
1330−-- let
1331−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
1332−-- expression = bitAndDistinct #col
1333−-- in printSQL expression
1334−-- :}
1335−-- bit_and(DISTINCT "col")
1336−bitAndDistinct
1337− :: PGIntegral int
1338− => Expression schema relations 'Ungrouped params (nullity int)
1339− -- ^ what to aggregate
1340− -> Expression schema relations ('Grouped bys) params (nullity int)
1341−bitAndDistinct = unsafeAggregateDistinct "bit_and"
1342−
1343−-- | >>> :{
1344−-- let
1345−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
1346−-- expression = bitOrDistinct #col
1347−-- in printSQL expression
1348−-- :}
1349−-- bit_or(DISTINCT "col")
1350−bitOrDistinct
1351− :: PGIntegral int
1352− => Expression schema relations 'Ungrouped params (nullity int)
1353− -- ^ what to aggregate
1354− -> Expression schema relations ('Grouped bys) params (nullity int)
1355−bitOrDistinct = unsafeAggregateDistinct "bit_or"
1356−
1357−-- | >>> :{
1358−-- let
1359−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
1360−-- expression = boolAnd #col
1361−-- in printSQL expression
1362−-- :}
1363−-- bool_and("col")
1364−boolAnd
1365− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)
1366− -- ^ what to aggregate
1367− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)
1368−boolAnd = unsafeAggregate "bool_and"
1369−
1370−-- | >>> :{
1371−-- let
1372−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
1373−-- expression = boolOr #col
1374−-- in printSQL expression
1375−-- :}
1376−-- bool_or("col")
1377−boolOr
1378− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)
1379− -- ^ what to aggregate
1380− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)
1381−boolOr = unsafeAggregate "bool_or"
1382−
1383−-- | >>> :{
1384−-- let
1385−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
1386−-- expression = boolAndDistinct #col
1387−-- in printSQL expression
1388−-- :}
1389−-- bool_and(DISTINCT "col")
1390−boolAndDistinct
1391− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)
1392− -- ^ what to aggregate
1393− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)
1394−boolAndDistinct = unsafeAggregateDistinct "bool_and"
1395−
1396−-- | >>> :{
1397−-- let
1398−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
1399−-- expression = boolOrDistinct #col
1400−-- in printSQL expression
1401−-- :}
1402−-- bool_or(DISTINCT "col")
1403−boolOrDistinct
1404− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)
1405− -- ^ what to aggregate
1406− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)
1407−boolOrDistinct = unsafeAggregateDistinct "bool_or"
1408−
1409−-- | A special aggregation that does not require an input
1410−--
1411−-- >>> printSQL countStar
1412−-- count(*)
1413−countStar
1414− :: Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)
1415−countStar = UnsafeExpression $ "count(*)"
1416−
1417−-- | >>> :{
1418−-- let
1419−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)
1420−-- expression = count #col
1421−-- in printSQL expression
1422−-- :}
1423−-- count("col")
1424−count
1425− :: Expression schema relations 'Ungrouped params ty
1426− -- ^ what to count
1427− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)
1428−count = unsafeAggregate "count"
1429−
1430−-- | >>> :{
1431−-- let
1432−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)
1433−-- expression = countDistinct #col
1434−-- in printSQL expression
1435−-- :}
1436−-- count(DISTINCT "col")
1437−countDistinct
1438− :: Expression schema relations 'Ungrouped params ty
1439− -- ^ what to count
1440− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)
1441−countDistinct = unsafeAggregateDistinct "count"
1442−
1443−-- | synonym for `boolAnd`
1444−--
1445−-- >>> :{
1446−-- let
1447−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
1448−-- expression = every #col
1449−-- in printSQL expression
1450−-- :}
1451−-- every("col")
1452−every
1453− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)
1454− -- ^ what to aggregate
1455− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)
1456−every = unsafeAggregate "every"
1457−
1458−-- | synonym for `boolAndDistinct`
1459−--
1460−-- >>> :{
1461−-- let
1462−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
1463−-- expression = everyDistinct #col
1464−-- in printSQL expression
1465−-- :}
1466−-- every(DISTINCT "col")
1467−everyDistinct
1468− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)
1469− -- ^ what to aggregate
1470− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)
1471−everyDistinct = unsafeAggregateDistinct "every"
1472−
1473−-- | minimum and maximum aggregation
1474−max_, min_, maxDistinct, minDistinct
1475− :: Expression schema relations 'Ungrouped params (nullity ty)
1476− -- ^ what to aggregate
1477− -> Expression schema relations ('Grouped bys) params (nullity ty)
1478−max_ = unsafeAggregate "max"
1479−min_ = unsafeAggregate "min"
1480−maxDistinct = unsafeAggregateDistinct "max"
1481−minDistinct = unsafeAggregateDistinct "min"
1482−
1483−{-----------------------------------------
1484−type expressions
1485−-----------------------------------------}
1486−
1487−-- | `TypeExpression`s are used in `cast`s and `createTable` commands.
1488−newtype TypeExpression (schema :: SchemaType) (ty :: PGType)
1489− = UnsafeTypeExpression { renderTypeExpression :: ByteString }
1490− deriving (GHC.Generic,Show,Eq,Ord,NFData)
1491−
1492−instance (Has alias schema ('Typedef ty))
1493− => IsLabel alias (TypeExpression schema ty) where
1494− fromLabel = UnsafeTypeExpression (renderAlias (fromLabel @alias))
1495−
1496−-- | logical Boolean (true/false)
1497−bool :: TypeExpression schema 'PGbool
1498−bool = UnsafeTypeExpression "bool"
1499−-- | signed two-byte integer
1500−int2, smallint :: TypeExpression schema 'PGint2
1501−int2 = UnsafeTypeExpression "int2"
1502−smallint = UnsafeTypeExpression "smallint"
1503−-- | signed four-byte integer
1504−int4, int, integer :: TypeExpression schema 'PGint4
1505−int4 = UnsafeTypeExpression "int4"
1506−int = UnsafeTypeExpression "int"
1507−integer = UnsafeTypeExpression "integer"
1508−-- | signed eight-byte integer
1509−int8, bigint :: TypeExpression schema 'PGint8
1510−int8 = UnsafeTypeExpression "int8"
1511−bigint = UnsafeTypeExpression "bigint"
1512−-- | arbitrary precision numeric type
1513−numeric :: TypeExpression schema 'PGnumeric
1514−numeric = UnsafeTypeExpression "numeric"
1515−-- | single precision floating-point number (4 bytes)
1516−float4, real :: TypeExpression schema 'PGfloat4
1517−float4 = UnsafeTypeExpression "float4"
1518−real = UnsafeTypeExpression "real"
1519−-- | double precision floating-point number (8 bytes)
1520−float8, doublePrecision :: TypeExpression schema 'PGfloat8
1521−float8 = UnsafeTypeExpression "float8"
1522−doublePrecision = UnsafeTypeExpression "double precision"
1523−-- | variable-length character string
1524−text :: TypeExpression schema 'PGtext
1525−text = UnsafeTypeExpression "text"
1526−-- | fixed-length character string
1527−char, character
1528− :: (KnownNat n, 1 <= n)
1529− => proxy n
1530− -> TypeExpression schema ('PGchar n)
1531−char p = UnsafeTypeExpression $ "char(" <> renderNat p <> ")"
1532−character p = UnsafeTypeExpression $ "character(" <> renderNat p <> ")"
1533−-- | variable-length character string
1534−varchar, characterVarying
1535− :: (KnownNat n, 1 <= n)
1536− => proxy n
1537− -> TypeExpression schema ('PGvarchar n)
1538−varchar p = UnsafeTypeExpression $ "varchar(" <> renderNat p <> ")"
1539−characterVarying p = UnsafeTypeExpression $
1540− "character varying(" <> renderNat p <> ")"
1541−-- | binary data ("byte array")
1542−bytea :: TypeExpression schema 'PGbytea
1543−bytea = UnsafeTypeExpression "bytea"
1544−-- | date and time (no time zone)
1545−timestamp :: TypeExpression schema 'PGtimestamp
1546−timestamp = UnsafeTypeExpression "timestamp"
1547−-- | date and time, including time zone
1548−timestampWithTimeZone :: TypeExpression schema 'PGtimestamptz
1549−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"
1550−-- | calendar date (year, month, day)
1551−date :: TypeExpression schema 'PGdate
1552−date = UnsafeTypeExpression "date"
1553−-- | time of day (no time zone)
1554−time :: TypeExpression schema 'PGtime
1555−time = UnsafeTypeExpression "time"
1556−-- | time of day, including time zone
1557−timeWithTimeZone :: TypeExpression schema 'PGtimetz
1558−timeWithTimeZone = UnsafeTypeExpression "time with time zone"
1559−-- | time span
1560−interval :: TypeExpression schema 'PGinterval
1561−interval = UnsafeTypeExpression "interval"
1562−-- | universally unique identifier
1563−uuid :: TypeExpression schema 'PGuuid
1564−uuid = UnsafeTypeExpression "uuid"
1565−-- | IPv4 or IPv6 host address
1566−inet :: TypeExpression schema 'PGinet
1567−inet = UnsafeTypeExpression "inet"
1568−-- | textual JSON data
1569−json :: TypeExpression schema 'PGjson
1570−json = UnsafeTypeExpression "json"
1571−-- | binary JSON data, decomposed
1572−jsonb :: TypeExpression schema 'PGjsonb
1573−jsonb = UnsafeTypeExpression "jsonb"
1574−-- | variable length array
1575−vararray
1576− :: TypeExpression schema pg
1577− -> TypeExpression schema ('PGvararray pg)
1578−vararray ty = UnsafeTypeExpression $ renderTypeExpression ty <> "[]"
1579−-- | fixed length array
1580−--
1581−-- >>> renderTypeExpression (fixarray (Proxy @2) json)
1582−-- "json[2]"
1583−fixarray
1584− :: KnownNat n
1585− => proxy n
1586− -> TypeExpression schema pg
1587− -> TypeExpression schema ('PGfixarray n pg)
1588−fixarray p ty = UnsafeTypeExpression $
1589− renderTypeExpression ty <> "[" <> renderNat p <> "]"
1590−
1591−-- | `pgtype` is a demoted version of a `PGType`
1592−class PGTyped schema (ty :: PGType) where pgtype :: TypeExpression schema ty
1593−instance PGTyped schema 'PGbool where pgtype = bool
1594−instance PGTyped schema 'PGint2 where pgtype = int2
1595−instance PGTyped schema 'PGint4 where pgtype = int4
1596−instance PGTyped schema 'PGint8 where pgtype = int8
1597−instance PGTyped schema 'PGnumeric where pgtype = numeric
1598−instance PGTyped schema 'PGfloat4 where pgtype = float4
1599−instance PGTyped schema 'PGfloat8 where pgtype = float8
1600−instance PGTyped schema 'PGtext where pgtype = text
1601−instance (KnownNat n, 1 <= n)
1602− => PGTyped schema ('PGchar n) where pgtype = char (Proxy @n)
1603−instance (KnownNat n, 1 <= n)
1604− => PGTyped schema ('PGvarchar n) where pgtype = varchar (Proxy @n)
1605−instance PGTyped schema 'PGbytea where pgtype = bytea
1606−instance PGTyped schema 'PGtimestamp where pgtype = timestamp
1607−instance PGTyped schema 'PGtimestamptz where pgtype = timestampWithTimeZone
1608−instance PGTyped schema 'PGdate where pgtype = date
1609−instance PGTyped schema 'PGtime where pgtype = time
1610−instance PGTyped schema 'PGtimetz where pgtype = timeWithTimeZone
1611−instance PGTyped schema 'PGinterval where pgtype = interval
1612−instance PGTyped schema 'PGuuid where pgtype = uuid
1613−instance PGTyped schema 'PGjson where pgtype = json
1614−instance PGTyped schema 'PGjsonb where pgtype = jsonb
1615−instance PGTyped schema ty => PGTyped schema ('PGvararray ty) where
1616− pgtype = vararray (pgtype @schema @ty)
1617−instance (KnownNat n, PGTyped schema ty) => PGTyped schema ('PGfixarray n ty) where
1618− pgtype = fixarray (Proxy @n) (pgtype @schema @ty)
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Aggregate.hsnew file+462
@@ -0,0 +1,462 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Aggregate
3+Description: Aggregate functions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Aggregate functions
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , DeriveGeneric
14+ , FlexibleContexts
15+ , FlexibleInstances
16+ , FunctionalDependencies
17+ , LambdaCase
18+ , MultiParamTypeClasses
19+ , OverloadedStrings
20+ , PolyKinds
21+ , TypeFamilies
22+ , TypeOperators
23+ , UndecidableInstances
24+#-}
25+
26+module Squeal.PostgreSQL.Expression.Aggregate
27+ ( Aggregate (..)
28+ , Distinction (..)
29+ , PGSum
30+ , PGAvg
31+ ) where
32+
33+import Control.DeepSeq
34+import Data.ByteString (ByteString)
35+import Data.Kind
36+import GHC.TypeLits
37+
38+import qualified GHC.Generics as GHC
39+import qualified Generics.SOP as SOP
40+
41+import Squeal.PostgreSQL.Alias
42+import Squeal.PostgreSQL.Expression
43+import Squeal.PostgreSQL.List
44+import Squeal.PostgreSQL.Render
45+import Squeal.PostgreSQL.Schema
46+
47+-- $setup
48+-- >>> import Squeal.PostgreSQL
49+
50+{- |
51+`Aggregate` functions compute a single result from a set of input values.
52+`Aggregate` functions can be used as `GroupedBy` `Expression`s as well
53+as `Squeal.PostgreSQL.Expression.Window.WindowFunction`s.
54+-}
55+class Aggregate expr1 exprN aggr
56+ | aggr -> expr1, aggr -> exprN where
57+
58+ -- | A special aggregation that does not require an input
59+ --
60+ -- >>> :{
61+ -- let
62+ -- expression :: Expression '[] commons ('Grouped bys) schemas params from ('NotNull 'PGint8)
63+ -- expression = countStar
64+ -- in printSQL expression
65+ -- :}
66+ -- count(*)
67+ countStar :: aggr ('NotNull 'PGint8)
68+
69+ -- | >>> :{
70+ -- let
71+ -- expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null ty]] ('NotNull 'PGint8)
72+ -- expression = count (All #col)
73+ -- in printSQL expression
74+ -- :}
75+ -- count(ALL "col")
76+ count
77+ :: expr1 ty
78+ -- ^ what to count
79+ -> aggr ('NotNull 'PGint8)
80+
81+ -- | >>> :{
82+ -- let
83+ -- expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Null 'PGnumeric)
84+ -- expression = sum_ (Distinct #col)
85+ -- in printSQL expression
86+ -- :}
87+ -- sum(DISTINCT "col")
88+ sum_
89+ :: expr1 (null ty)
90+ -> aggr ('Null (PGSum ty))
91+
92+ -- | input values, including nulls, concatenated into an array
93+ arrayAgg
94+ :: expr1 ty
95+ -> aggr ('Null ('PGvararray ty))
96+
97+ -- | aggregates values as a JSON array
98+ jsonAgg
99+ :: expr1 ty
100+ -> aggr ('Null 'PGjson)
101+
102+ -- | aggregates values as a JSON array
103+ jsonbAgg
104+ :: expr1 ty
105+ -> aggr ('Null 'PGjsonb)
106+
107+ {- |
108+ the bitwise AND of all non-null input values, or null if none
109+
110+ >>> :{
111+ let
112+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGint4]] ('Null 'PGint4)
113+ expression = bitAnd (Distinct #col)
114+ in printSQL expression
115+ :}
116+ bit_and(DISTINCT "col")
117+ -}
118+ bitAnd
119+ :: int `In` PGIntegral
120+ => expr1 (null int)
121+ -- ^ what to aggregate
122+ -> aggr ('Null int)
123+
124+ {- |
125+ the bitwise OR of all non-null input values, or null if none
126+
127+ >>> :{
128+ let
129+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGint4]] ('Null 'PGint4)
130+ expression = bitOr (All #col)
131+ in printSQL expression
132+ :}
133+ bit_or(ALL "col")
134+ -}
135+ bitOr
136+ :: int `In` PGIntegral
137+ => expr1 (null int)
138+ -- ^ what to aggregate
139+ -> aggr ('Null int)
140+
141+ {- |
142+ true if all input values are true, otherwise false
143+
144+ >>> :{
145+ let
146+ winFun :: WindowFunction '[] commons 'Ungrouped schemas params '[tab ::: '["col" ::: null 'PGbool]] ('Null 'PGbool)
147+ winFun = boolAnd #col
148+ in printSQL winFun
149+ :}
150+ bool_and("col")
151+ -}
152+ boolAnd
153+ :: expr1 (null 'PGbool)
154+ -- ^ what to aggregate
155+ -> aggr ('Null 'PGbool)
156+
157+ {- |
158+ true if at least one input value is true, otherwise false
159+
160+ >>> :{
161+ let
162+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGbool]] ('Null 'PGbool)
163+ expression = boolOr (All #col)
164+ in printSQL expression
165+ :}
166+ bool_or(ALL "col")
167+ -}
168+ boolOr
169+ :: expr1 (null 'PGbool)
170+ -- ^ what to aggregate
171+ -> aggr ('Null 'PGbool)
172+
173+ {- |
174+ equivalent to `boolAnd`
175+
176+ >>> :{
177+ let
178+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGbool]] ('Null 'PGbool)
179+ expression = every (Distinct #col)
180+ in printSQL expression
181+ :}
182+ every(DISTINCT "col")
183+ -}
184+ every
185+ :: expr1 (null 'PGbool)
186+ -- ^ what to aggregate
187+ -> aggr ('Null 'PGbool)
188+
189+ {- |maximum value of expression across all input values-}
190+ max_
191+ :: expr1 (null ty)
192+ -- ^ what to maximize
193+ -> aggr ('Null ty)
194+
195+ -- | minimum value of expression across all input values
196+ min_
197+ :: expr1 (null ty)
198+ -- ^ what to minimize
199+ -> aggr ('Null ty)
200+
201+ -- | the average (arithmetic mean) of all input values
202+ avg
203+ :: expr1 (null ty)
204+ -- ^ what to average
205+ -> aggr ('Null (PGAvg ty))
206+
207+ {- | correlation coefficient
208+
209+ >>> :{
210+ let
211+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)
212+ expression = corr (All (#y *: #x))
213+ in printSQL expression
214+ :}
215+ corr(ALL "y", "x")
216+ -}
217+ corr
218+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
219+ -> aggr ('Null 'PGfloat8)
220+
221+ {- | population covariance
222+
223+ >>> :{
224+ let
225+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)
226+ expression = covarPop (All (#y *: #x))
227+ in printSQL expression
228+ :}
229+ covar_pop(ALL "y", "x")
230+ -}
231+ covarPop
232+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
233+ -> aggr ('Null 'PGfloat8)
234+
235+ {- | sample covariance
236+
237+ >>> :{
238+ let
239+ winFun :: WindowFunction '[] c 'Ungrouped s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)
240+ winFun = covarSamp (#y *: #x)
241+ in printSQL winFun
242+ :}
243+ covar_samp("y", "x")
244+ -}
245+ covarSamp
246+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
247+ -> aggr ('Null 'PGfloat8)
248+
249+ {- | average of the independent variable (sum(X)/N)
250+
251+ >>> :{
252+ let
253+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)
254+ expression = regrAvgX (All (#y *: #x))
255+ in printSQL expression
256+ :}
257+ regr_avgx(ALL "y", "x")
258+ -}
259+ regrAvgX
260+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
261+ -> aggr ('Null 'PGfloat8)
262+
263+ {- | average of the dependent variable (sum(Y)/N)
264+
265+ >>> :{
266+ let
267+ winFun :: WindowFunction '[] c 'Ungrouped s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)
268+ winFun = regrAvgY (#y *: #x)
269+ in printSQL winFun
270+ :}
271+ regr_avgy("y", "x")
272+ -}
273+ regrAvgY
274+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
275+ -> aggr ('Null 'PGfloat8)
276+
277+ {- | number of input rows in which both expressions are nonnull
278+
279+ >>> :{
280+ let
281+ winFun :: WindowFunction '[] c 'Ungrouped s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGint8)
282+ winFun = regrCount (#y *: #x)
283+ in printSQL winFun
284+ :}
285+ regr_count("y", "x")
286+ -}
287+ regrCount
288+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
289+ -> aggr ('Null 'PGint8)
290+
291+ {- | y-intercept of the least-squares-fit linear equation determined by the (X, Y) pairs
292+ >>> :{
293+ let
294+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)
295+ expression = regrIntercept (All (#y *: #x))
296+ in printSQL expression
297+ :}
298+ regr_intercept(ALL "y", "x")
299+ -}
300+ regrIntercept
301+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
302+ -> aggr ('Null 'PGfloat8)
303+
304+ -- | @regr_r2(Y, X)@, square of the correlation coefficient
305+ regrR2
306+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
307+ -> aggr ('Null 'PGfloat8)
308+
309+ -- | @regr_slope(Y, X)@, slope of the least-squares-fit linear equation
310+ -- determined by the (X, Y) pairs
311+ regrSlope
312+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
313+ -> aggr ('Null 'PGfloat8)
314+
315+ -- | @regr_sxx(Y, X)@, sum(X^2) - sum(X)^2/N
316+ -- (“sum of squares” of the independent variable)
317+ regrSxx
318+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
319+ -> aggr ('Null 'PGfloat8)
320+
321+ -- | @regr_sxy(Y, X)@, sum(X*Y) - sum(X) * sum(Y)/N
322+ -- (“sum of products” of independent times dependent variable)
323+ regrSxy
324+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
325+ -> aggr ('Null 'PGfloat8)
326+
327+ -- | @regr_syy(Y, X)@, sum(Y^2) - sum(Y)^2/N
328+ -- (“sum of squares” of the dependent variable)
329+ regrSyy
330+ :: exprN '[null 'PGfloat8, null 'PGfloat8]
331+ -> aggr ('Null 'PGfloat8)
332+
333+ -- | historical alias for `stddevSamp`
334+ stddev
335+ :: expr1 (null ty)
336+ -> aggr ('Null (PGAvg ty))
337+
338+ -- | population standard deviation of the input values
339+ stddevPop
340+ :: expr1 (null ty)
341+ -> aggr ('Null (PGAvg ty))
342+
343+ -- | sample standard deviation of the input values
344+ stddevSamp
345+ :: expr1 (null ty)
346+ -> aggr ('Null (PGAvg ty))
347+
348+ -- | historical alias for `varSamp`
349+ variance
350+ :: expr1 (null ty)
351+ -> aggr ('Null (PGAvg ty))
352+
353+ -- | population variance of the input values
354+ -- (square of the population standard deviation)
355+ varPop
356+ :: expr1 (null ty)
357+ -> aggr ('Null (PGAvg ty))
358+
359+ -- | sample variance of the input values
360+ -- (square of the sample standard deviation)
361+ varSamp
362+ :: expr1 (null ty)
363+ -> aggr ('Null (PGAvg ty))
364+
365+{- |
366+`Distinction`s are used for the input of `Aggregate` `Expression`s.
367+`All` invokes the aggregate once for each input row.
368+`Distinct` invokes the aggregate once for each distinct value of the expression
369+(or distinct set of values, for multiple expressions) found in the input
370+-}
371+data Distinction (expr :: kind -> Type) (ty :: kind)
372+ = All (expr ty)
373+ | Distinct (expr ty)
374+ deriving (GHC.Generic,Show,Eq,Ord)
375+instance NFData (Distinction (Expression outer commons grp schemas params from) ty)
376+instance RenderSQL (Distinction (Expression outer commons grp schemas params from) ty) where
377+ renderSQL = \case
378+ All x -> "ALL" <+> renderSQL x
379+ Distinct x -> "DISTINCT" <+> renderSQL x
380+instance SOP.SListI tys => RenderSQL
381+ (Distinction (NP (Expression outer commons grp schemas params from)) tys) where
382+ renderSQL = \case
383+ All xs -> "ALL" <+> renderCommaSeparated renderSQL xs
384+ Distinct xs -> "DISTINCT" <+> renderCommaSeparated renderSQL xs
385+
386+instance Aggregate
387+ (Distinction (Expression outer commons 'Ungrouped schemas params from))
388+ (Distinction (NP (Expression outer commons 'Ungrouped schemas params from)))
389+ (Expression outer commons ('Grouped bys) schemas params from) where
390+ countStar = UnsafeExpression "count(*)"
391+ count = unsafeAggregate1 "count"
392+ sum_ = unsafeAggregate1 "sum"
393+ arrayAgg = unsafeAggregate1 "array_agg"
394+ jsonAgg = unsafeAggregate1 "json_agg"
395+ jsonbAgg = unsafeAggregate1 "jsonb_agg"
396+ bitAnd = unsafeAggregate1 "bit_and"
397+ bitOr = unsafeAggregate1 "bit_or"
398+ boolAnd = unsafeAggregate1 "bool_and"
399+ boolOr = unsafeAggregate1 "bool_or"
400+ every = unsafeAggregate1 "every"
401+ max_ = unsafeAggregate1 "max"
402+ min_ = unsafeAggregate1 "min"
403+ avg = unsafeAggregate1 "avg"
404+ corr = unsafeAggregateN "corr"
405+ covarPop = unsafeAggregateN "covar_pop"
406+ covarSamp = unsafeAggregateN "covar_samp"
407+ regrAvgX = unsafeAggregateN "regr_avgx"
408+ regrAvgY = unsafeAggregateN "regr_avgy"
409+ regrCount = unsafeAggregateN "regr_count"
410+ regrIntercept = unsafeAggregateN "regr_intercept"
411+ regrR2 = unsafeAggregateN "regr_r2"
412+ regrSlope = unsafeAggregateN "regr_slope"
413+ regrSxx = unsafeAggregateN "regr_sxx"
414+ regrSxy = unsafeAggregateN "regr_sxy"
415+ regrSyy = unsafeAggregateN "regr_syy"
416+ stddev = unsafeAggregate1 "stddev"
417+ stddevPop = unsafeAggregate1 "stddev_pop"
418+ stddevSamp = unsafeAggregate1 "stddev_samp"
419+ variance = unsafeAggregate1 "variance"
420+ varPop = unsafeAggregate1 "var_pop"
421+ varSamp = unsafeAggregate1 "var_samp"
422+
423+-- | escape hatch to define aggregate functions
424+unsafeAggregate1
425+ :: ByteString -- ^ aggregate function
426+ -> Distinction (Expression outer commons 'Ungrouped schemas params from) x
427+ -> Expression outer commons ('Grouped bys) schemas params from y
428+unsafeAggregate1 fun x = UnsafeExpression $ fun <> parenthesized (renderSQL x)
429+
430+unsafeAggregateN
431+ :: SOP.SListI xs
432+ => ByteString -- ^ function
433+ -> Distinction (NP (Expression outer commons 'Ungrouped schemas params from)) xs
434+ -> Expression outer commons ('Grouped bys) schemas params from y
435+unsafeAggregateN fun xs = UnsafeExpression $ fun <> parenthesized (renderSQL xs)
436+
437+-- | A type family that calculates `PGSum``PGType` of
438+-- a given argument `PGType`.
439+type family PGSum ty where
440+ PGSum 'PGint2 = 'PGint8
441+ PGSum 'PGint4 = 'PGint8
442+ PGSum 'PGint8 = 'PGnumeric
443+ PGSum 'PGfloat4 = 'PGfloat4
444+ PGSum 'PGfloat8 = 'PGfloat8
445+ PGSum 'PGnumeric = 'PGnumeric
446+ PGSum 'PGinterval = 'PGinterval
447+ PGSum 'PGmoney = 'PGmoney
448+ PGSum pg = TypeError
449+ ( 'Text "Squeal type error: Cannot sum with argument type "
450+ ':<>: 'ShowType pg )
451+
452+-- | A type family that calculates `PGAvg` type of a `PGType`.
453+type family PGAvg ty where
454+ PGAvg 'PGint2 = 'PGnumeric
455+ PGAvg 'PGint4 = 'PGnumeric
456+ PGAvg 'PGint8 = 'PGnumeric
457+ PGAvg 'PGnumeric = 'PGnumeric
458+ PGAvg 'PGfloat4 = 'PGfloat8
459+ PGAvg 'PGfloat8 = 'PGfloat8
460+ PGAvg 'PGinterval = 'PGinterval
461+ PGAvg pg = TypeError
462+ ('Text "Squeal type error: No average for " ':<>: 'ShowType pg)
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Collection.hsnew file+169
@@ -0,0 +1,169 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Collection
3+Description: Array and composite functions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Array and composite functions
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , DataKinds
14+ , FlexibleContexts
15+ , FlexibleInstances
16+ , MultiParamTypeClasses
17+ , OverloadedLabels
18+ , OverloadedStrings
19+ , RankNTypes
20+ , ScopedTypeVariables
21+ , TypeApplications
22+ , TypeFamilies
23+ , TypeOperators
24+ , UndecidableInstances
25+#-}
26+
27+module Squeal.PostgreSQL.Expression.Collection
28+ ( array
29+ , array1
30+ , array2
31+ , cardinality
32+ , index
33+ , unnest
34+ , row
35+ , field
36+ ) where
37+
38+import Data.String
39+import Data.Word (Word64)
40+
41+import qualified Generics.SOP as SOP
42+
43+import Squeal.PostgreSQL.Alias
44+import Squeal.PostgreSQL.Expression
45+import Squeal.PostgreSQL.Expression.Set
46+import Squeal.PostgreSQL.List
47+import Squeal.PostgreSQL.Render
48+import Squeal.PostgreSQL.Schema
49+
50+-- $setup
51+-- >>> import Squeal.PostgreSQL
52+
53+-- | >>> printSQL $ array [null_, false, true]
54+-- ARRAY[NULL, FALSE, TRUE]
55+array
56+ :: [Expression outer commons grp schemas params from ty]
57+ -- ^ array elements
58+ -> Expression outer commons grp schemas params from (null ('PGvararray ty))
59+array xs = UnsafeExpression $ "ARRAY" <>
60+ bracketed (commaSeparated (renderSQL <$> xs))
61+
62+{- | construct a 1-dimensional fixed length array
63+
64+>>> printSQL $ array1 (null_ :* false *: true)
65+ARRAY[NULL, FALSE, TRUE]
66+
67+>>> :type array1 (null_ :* false *: true)
68+array1 (null_ :* false *: true)
69+ :: Expression
70+ outer
71+ commons
72+ grp
73+ schemas
74+ params
75+ from
76+ (null ('PGfixarray '[3] ('Null 'PGbool)))
77+-}
78+array1
79+ :: (n ~ Length tys, SOP.All ((~) ty) tys)
80+ => NP (Expression outer commons grp schemas params from) tys
81+ -> Expression outer commons grp schemas params from (null ('PGfixarray '[n] ty))
82+array1 xs = UnsafeExpression $ "ARRAY" <>
83+ bracketed (renderCommaSeparated renderSQL xs)
84+
85+{- | construct a 2-dimensional fixed length array
86+
87+>>> printSQL $ array2 ((null_ :* false *: true) *: (false :* null_ *: true))
88+ARRAY[[NULL, FALSE, TRUE], [FALSE, NULL, TRUE]]
89+
90+>>> :type array2 ((null_ :* false *: true) *: (false :* null_ *: true))
91+array2 ((null_ :* false *: true) *: (false :* null_ *: true))
92+ :: Expression
93+ outer
94+ commons
95+ grp
96+ schemas
97+ params
98+ from
99+ (null ('PGfixarray '[2, 3] ('Null 'PGbool)))
100+-}
101+array2
102+ :: ( SOP.All ((~) tys) tyss
103+ , SOP.All SOP.SListI tyss
104+ , Length tyss ~ n1
105+ , SOP.All ((~) ty) tys
106+ , Length tys ~ n2 )
107+ => NP (NP (Expression outer commons grp schemas params from)) tyss
108+ -> Expression outer commons grp schemas params from (null ('PGfixarray '[n1,n2] ty))
109+array2 xss = UnsafeExpression $ "ARRAY" <>
110+ bracketed (renderCommaSeparatedConstraint @SOP.SListI (bracketed . renderCommaSeparated renderSQL) xss)
111+
112+-- | >>> printSQL $ cardinality (array [null_, false, true])
113+-- cardinality(ARRAY[NULL, FALSE, TRUE])
114+cardinality :: null ('PGvararray ty) --> null 'PGint8
115+cardinality = unsafeFunction "cardinality"
116+
117+-- | >>> printSQL $ array [null_, false, true] & index 2
118+-- (ARRAY[NULL, FALSE, TRUE])[2]
119+index
120+ :: Word64 -- ^ index
121+ -> null ('PGvararray ty) --> NullifyType ty
122+index n expr = UnsafeExpression $
123+ parenthesized (renderSQL expr) <> "[" <> fromString (show n) <> "]"
124+
125+-- | Expand an array to a set of rows
126+unnest :: SetFunction "unnest" (null ('PGvararray ty)) '["unnest" ::: ty]
127+unnest = unsafeSetFunction
128+
129+-- | A row constructor is an expression that builds a row value
130+-- (also called a composite value) using values for its member fields.
131+--
132+-- >>> :{
133+-- type Complex = 'PGcomposite
134+-- '[ "real" ::: 'NotNull 'PGfloat8
135+-- , "imaginary" ::: 'NotNull 'PGfloat8 ]
136+-- :}
137+--
138+-- >>> let i = row (0 `as` #real :* 1 `as` #imaginary) :: Expression outer commons grp schemas params from ('NotNull Complex)
139+-- >>> printSQL i
140+-- ROW(0, 1)
141+row
142+ :: SOP.SListI row
143+ => NP (Aliased (Expression outer commons grp schemas params from)) row
144+ -- ^ zero or more expressions for the row field values
145+ -> Expression outer commons grp schemas params from (null ('PGcomposite row))
146+row exprs = UnsafeExpression $ "ROW" <> parenthesized
147+ (renderCommaSeparated (\ (expr `As` _) -> renderSQL expr) exprs)
148+
149+-- | >>> :{
150+-- type Complex = 'PGcomposite
151+-- '[ "real" ::: 'NotNull 'PGfloat8
152+-- , "imaginary" ::: 'NotNull 'PGfloat8 ]
153+-- type Schema = '["complex" ::: 'Typedef Complex]
154+-- :}
155+--
156+-- >>> let i = row (0 `as` #real :* 1 `as` #imaginary) :: Expression outer '[] grp (Public Schema) from params ('NotNull Complex)
157+-- >>> printSQL $ i & field #complex #imaginary
158+-- (ROW(0, 1)::"complex")."imaginary"
159+field
160+ :: ( Has sch schemas schema
161+ , Has tydef schema ('Typedef ('PGcomposite row))
162+ , Has field row ty)
163+ => QualifiedAlias sch tydef -- ^ row type
164+ -> Alias field -- ^ field name
165+ -> Expression outer commons grp schemas params from ('NotNull ('PGcomposite row))
166+ -> Expression outer commons grp schemas params from ty
167+field td fld expr = UnsafeExpression $
168+ parenthesized (renderSQL expr <> "::" <> renderSQL td)
169+ <> "." <> renderSQL fld
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Comparison.hsnew file+206
@@ -0,0 +1,206 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Comparison
3+Description: Comparison expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Comparison functions and operators
9+-}
10+
11+{-# LANGUAGE
12+ OverloadedStrings
13+ , RankNTypes
14+ , TypeInType
15+ , TypeOperators
16+#-}
17+
18+module Squeal.PostgreSQL.Expression.Comparison
19+ ( (.==)
20+ , (./=)
21+ , (.>=)
22+ , (.<)
23+ , (.<=)
24+ , (.>)
25+ , greatest
26+ , least
27+ , BetweenExpr
28+ , between
29+ , notBetween
30+ , betweenSymmetric
31+ , notBetweenSymmetric
32+ , isDistinctFrom
33+ , isNotDistinctFrom
34+ , isTrue
35+ , isNotTrue
36+ , isFalse
37+ , isNotFalse
38+ , isUnknown
39+ , isNotUnknown
40+ ) where
41+
42+import Data.ByteString
43+
44+import Squeal.PostgreSQL.Expression
45+import Squeal.PostgreSQL.Expression.Logic
46+import Squeal.PostgreSQL.Render
47+import Squeal.PostgreSQL.Schema
48+
49+-- $setup
50+-- >>> import Squeal.PostgreSQL
51+
52+-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`
53+-- will produce @NULL@s if one of their arguments is @NULL@.
54+--
55+-- >>> printSQL $ true .== null_
56+-- (TRUE = NULL)
57+(.==) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
58+(.==) = unsafeBinaryOp "="
59+infix 4 .==
60+
61+-- | >>> printSQL $ true ./= null_
62+-- (TRUE <> NULL)
63+(./=) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
64+(./=) = unsafeBinaryOp "<>"
65+infix 4 ./=
66+
67+-- | >>> printSQL $ true .>= null_
68+-- (TRUE >= NULL)
69+(.>=) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
70+(.>=) = unsafeBinaryOp ">="
71+infix 4 .>=
72+
73+-- | >>> printSQL $ true .< null_
74+-- (TRUE < NULL)
75+(.<) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
76+(.<) = unsafeBinaryOp "<"
77+infix 4 .<
78+
79+-- | >>> printSQL $ true .<= null_
80+-- (TRUE <= NULL)
81+(.<=) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
82+(.<=) = unsafeBinaryOp "<="
83+infix 4 .<=
84+
85+-- | >>> printSQL $ true .> null_
86+-- (TRUE > NULL)
87+(.>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
88+(.>) = unsafeBinaryOp ">"
89+infix 4 .>
90+
91+-- | >>> let expr = greatest [param @1] currentTimestamp :: Expression outer commons grp schemas '[ 'NotNull 'PGtimestamptz] from ('NotNull 'PGtimestamptz)
92+-- >>> printSQL expr
93+-- GREATEST(($1 :: timestamp with time zone), CURRENT_TIMESTAMP)
94+greatest :: FunctionVar ty ty ty
95+greatest = unsafeFunctionVar "GREATEST"
96+
97+-- | >>> printSQL $ least [null_] currentTimestamp
98+-- LEAST(NULL, CURRENT_TIMESTAMP)
99+least :: FunctionVar ty ty ty
100+least = unsafeFunctionVar "LEAST"
101+
102+{- |
103+A @RankNType@ for comparison expressions like `between`.
104+-}
105+type BetweenExpr
106+ = forall outer commons grp schemas params from ty
107+ . Expression outer commons grp schemas params from ty
108+ -> ( Expression outer commons grp schemas params from ty
109+ , Expression outer commons grp schemas params from ty ) -- ^ bounds
110+ -> Condition outer commons grp schemas params from
111+
112+unsafeBetweenExpr :: ByteString -> BetweenExpr
113+unsafeBetweenExpr fun a (x,y) = UnsafeExpression $
114+ renderSQL a <+> fun <+> renderSQL x <+> "AND" <+> renderSQL y
115+
116+{- | >>> printSQL $ true `between` (null_, false)
117+TRUE BETWEEN NULL AND FALSE
118+-}
119+between :: BetweenExpr
120+between = unsafeBetweenExpr "BETWEEN"
121+
122+{- | >>> printSQL $ true `notBetween` (null_, false)
123+TRUE NOT BETWEEN NULL AND FALSE
124+-}
125+notBetween :: BetweenExpr
126+notBetween = unsafeBetweenExpr "NOT BETWEEN"
127+
128+{- | between, after sorting the comparison values
129+
130+>>> printSQL $ true `betweenSymmetric` (null_, false)
131+TRUE BETWEEN SYMMETRIC NULL AND FALSE
132+-}
133+betweenSymmetric :: BetweenExpr
134+betweenSymmetric = unsafeBetweenExpr "BETWEEN SYMMETRIC"
135+
136+{- | not between, after sorting the comparison values
137+
138+>>> printSQL $ true `notBetweenSymmetric` (null_, false)
139+TRUE NOT BETWEEN SYMMETRIC NULL AND FALSE
140+-}
141+notBetweenSymmetric :: BetweenExpr
142+notBetweenSymmetric = unsafeBetweenExpr "NOT BETWEEN SYMMETRIC"
143+
144+{- | not equal, treating null like an ordinary value
145+
146+>>> printSQL $ true `isDistinctFrom` null_
147+(TRUE IS DISTINCT FROM NULL)
148+-}
149+isDistinctFrom :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
150+isDistinctFrom = unsafeBinaryOp "IS DISTINCT FROM"
151+
152+{- | equal, treating null like an ordinary value
153+
154+>>> printSQL $ true `isNotDistinctFrom` null_
155+(TRUE IS NOT DISTINCT FROM NULL)
156+-}
157+isNotDistinctFrom :: Operator (null0 ty) (null1 ty) ('NotNull 'PGbool)
158+isNotDistinctFrom = unsafeBinaryOp "IS NOT DISTINCT FROM"
159+
160+{- | is true
161+
162+>>> printSQL $ true & isTrue
163+(TRUE IS TRUE)
164+-}
165+isTrue :: null0 'PGbool --> null1 'PGbool
166+isTrue = unsafeRightOp "IS TRUE"
167+
168+{- | is false or unknown
169+
170+>>> printSQL $ true & isNotTrue
171+(TRUE IS NOT TRUE)
172+-}
173+isNotTrue :: null0 'PGbool --> null1 'PGbool
174+isNotTrue = unsafeRightOp "IS NOT TRUE"
175+
176+{- | is false
177+
178+>>> printSQL $ true & isFalse
179+(TRUE IS FALSE)
180+-}
181+isFalse :: null0 'PGbool --> null1 'PGbool
182+isFalse = unsafeRightOp "IS FALSE"
183+
184+{- | is true or unknown
185+
186+>>> printSQL $ true & isNotFalse
187+(TRUE IS NOT FALSE)
188+-}
189+isNotFalse :: null0 'PGbool --> null1 'PGbool
190+isNotFalse = unsafeRightOp "IS NOT FALSE"
191+
192+{- | is unknown
193+
194+>>> printSQL $ true & isUnknown
195+(TRUE IS UNKNOWN)
196+-}
197+isUnknown :: null0 'PGbool --> null1 'PGbool
198+isUnknown = unsafeRightOp "IS UNKNOWN"
199+
200+{- | is true or false
201+
202+>>> printSQL $ true & isNotUnknown
203+(TRUE IS NOT UNKNOWN)
204+-}
205+isNotUnknown :: null0 'PGbool --> null1 'PGbool
206+isNotUnknown = unsafeRightOp "IS NOT UNKNOWN"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Json.hsnew file+462
@@ -0,0 +1,462 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Json
3+Description: Json and Jsonb functions and operators
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Json and Jsonb functions and operators
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , FlexibleContexts
14+ , FlexibleInstances
15+ , GADTs
16+ , OverloadedLabels
17+ , OverloadedStrings
18+ , PolyKinds
19+ , RankNTypes
20+ , ScopedTypeVariables
21+ , TypeApplications
22+ , TypeOperators
23+ , UndecidableInstances
24+ , UndecidableSuperClasses
25+#-}
26+
27+module Squeal.PostgreSQL.Expression.Json
28+ ( -- * Json and Jsonb operators
29+ (.->)
30+ , (.->>)
31+ , (.#>)
32+ , (.#>>)
33+ -- * Jsonb operators
34+ , (.?)
35+ , (.?|)
36+ , (.?&)
37+ , (.-.)
38+ , (#-.)
39+ -- * Json and Jsonb functions
40+ , toJson
41+ , toJsonb
42+ , arrayToJson
43+ , rowToJson
44+ , jsonBuildArray
45+ , jsonbBuildArray
46+ , JsonBuildObject (..)
47+ , jsonObject
48+ , jsonbObject
49+ , jsonZipObject
50+ , jsonbZipObject
51+ , jsonArrayLength
52+ , jsonbArrayLength
53+ , jsonTypeof
54+ , jsonbTypeof
55+ , jsonStripNulls
56+ , jsonbStripNulls
57+ , jsonbSet
58+ , jsonbInsert
59+ , jsonbPretty
60+ -- * Json and Jsonb set returning functions
61+ , jsonEach
62+ , jsonbEach
63+ , jsonEachText
64+ , jsonbEachText
65+ , jsonObjectKeys
66+ , jsonbObjectKeys
67+ , JsonPopulateFunction
68+ , jsonPopulateRecord
69+ , jsonbPopulateRecord
70+ , jsonPopulateRecordSet
71+ , jsonbPopulateRecordSet
72+ , JsonToRecordFunction
73+ , jsonToRecord
74+ , jsonbToRecord
75+ , jsonToRecordSet
76+ , jsonbToRecordSet
77+ ) where
78+
79+import Data.ByteString (ByteString)
80+import GHC.TypeLits
81+
82+import Squeal.PostgreSQL.Alias
83+import Squeal.PostgreSQL.Expression
84+import Squeal.PostgreSQL.Expression.Set
85+import Squeal.PostgreSQL.Expression.Type
86+import Squeal.PostgreSQL.List
87+import Squeal.PostgreSQL.Query
88+import Squeal.PostgreSQL.Render
89+import Squeal.PostgreSQL.Schema
90+
91+import qualified Generics.SOP as SOP
92+
93+-- $setup
94+-- >>> import Squeal.PostgreSQL
95+-- >>> import Data.Aeson
96+
97+{-----------------------------------------
98+ -- json and jsonb support
99+
100+See https://www.postgresql.org/docs/10/static/functions-json.html -- most
101+comments lifted directly from this page.
102+
103+Table 9.44: json and jsonb operators
104+-----------------------------------------}
105+
106+-- | Get JSON value (object field or array element) at a key.
107+(.->)
108+ :: (json `In` PGJsonType, key `In` PGJsonKey)
109+ => Operator (null json) (null key) ('Null json)
110+infixl 8 .->
111+(.->) = unsafeBinaryOp "->"
112+
113+-- | Get JSON value (object field or array element) at a key, as text.
114+(.->>)
115+ :: (json `In` PGJsonType, key `In` PGJsonKey)
116+ => Operator (null json) (null key) ('Null 'PGtext)
117+infixl 8 .->>
118+(.->>) = unsafeBinaryOp "->>"
119+
120+-- | Get JSON value at a specified path.
121+(.#>)
122+ :: json `In` PGJsonType
123+ => Operator (null json) (null ('PGvararray ('NotNull 'PGtext))) ('Null json)
124+infixl 8 .#>
125+(.#>) = unsafeBinaryOp "#>"
126+
127+-- | Get JSON value at a specified path as text.
128+(.#>>)
129+ :: json `In` PGJsonType
130+ => Operator (null json) (null ('PGvararray ('NotNull 'PGtext))) ('Null 'PGtext)
131+infixl 8 .#>>
132+(.#>>) = unsafeBinaryOp "#>>"
133+
134+-- Additional jsonb operators
135+
136+-- | Does the string exist as a top-level key within the JSON value?
137+(.?) :: Operator (null 'PGjsonb) (null 'PGtext) ('Null 'PGbool)
138+infixl 9 .?
139+(.?) = unsafeBinaryOp "?"
140+
141+-- | Do any of these array strings exist as top-level keys?
142+(.?|) :: Operator
143+ (null 'PGjsonb)
144+ (null ('PGvararray ('NotNull 'PGtext)))
145+ ('Null 'PGbool)
146+infixl 9 .?|
147+(.?|) = unsafeBinaryOp "?|"
148+
149+-- | Do all of these array strings exist as top-level keys?
150+(.?&) :: Operator
151+ (null 'PGjsonb)
152+ (null ('PGvararray ('NotNull 'PGtext)))
153+ ('Null 'PGbool)
154+infixl 9 .?&
155+(.?&) = unsafeBinaryOp "?&"
156+
157+-- | Delete a key or keys from a JSON object, or remove an array element.
158+--
159+-- If the right operand is
160+--
161+-- @ text @: Delete key / value pair or string element from left operand.
162+-- Key / value pairs are matched based on their key value,
163+--
164+-- @ text[] @: Delete multiple key / value pairs or string elements
165+-- from left operand. Key / value pairs are matched based on their key value,
166+--
167+-- @ integer @: Delete the array element with specified index (Negative integers
168+-- count from the end). Throws an error if top level container is not an array.
169+(.-.)
170+ :: key `In` '[ 'PGtext, 'PGvararray ('NotNull 'PGtext), 'PGint4, 'PGint2 ]
171+ => Operator (null 'PGjsonb) (null key) (null 'PGjsonb)
172+infixl 6 .-.
173+(.-.) = unsafeBinaryOp "-"
174+
175+-- | Delete the field or element with specified path (for JSON arrays, negative
176+-- integers count from the end)
177+(#-.) :: Operator (null 'PGjsonb) (null ('PGvararray ('NotNull 'PGtext))) (null 'PGjsonb)
178+infixl 6 #-.
179+(#-.) = unsafeBinaryOp "#-"
180+
181+{-----------------------------------------
182+Table 9.45: JSON creation functions
183+-----------------------------------------}
184+
185+-- | Returns the value as json. Arrays and composites are converted
186+-- (recursively) to arrays and objects; otherwise, if there is a cast from the
187+-- type to json, the cast function will be used to perform the conversion;
188+-- otherwise, a scalar value is produced. For any scalar type other than a
189+-- number, a Boolean, or a null value, the text representation will be used, in
190+-- such a fashion that it is a valid json value.
191+toJson :: null ty --> null 'PGjson
192+toJson = unsafeFunction "to_json"
193+
194+-- | Returns the value as jsonb. Arrays and composites are converted
195+-- (recursively) to arrays and objects; otherwise, if there is a cast from the
196+-- type to json, the cast function will be used to perform the conversion;
197+-- otherwise, a scalar value is produced. For any scalar type other than a
198+-- number, a Boolean, or a null value, the text representation will be used, in
199+-- such a fashion that it is a valid jsonb value.
200+toJsonb :: null ty --> null 'PGjsonb
201+toJsonb = unsafeFunction "to_jsonb"
202+
203+-- | Returns the array as a JSON array. A PostgreSQL multidimensional array
204+-- becomes a JSON array of arrays.
205+arrayToJson :: null ('PGvararray ty) --> null 'PGjson
206+arrayToJson = unsafeFunction "array_to_json"
207+
208+-- | Returns the row as a JSON object.
209+rowToJson :: null ('PGcomposite ty) --> null 'PGjson
210+rowToJson = unsafeFunction "row_to_json"
211+
212+-- | Builds a possibly-heterogeneously-typed JSON array out of a variadic
213+-- argument list.
214+jsonBuildArray :: SOP.SListI tuple => tuple ---> null 'PGjson
215+jsonBuildArray = unsafeFunctionN "json_build_array"
216+
217+-- | Builds a possibly-heterogeneously-typed (binary) JSON array out of a
218+-- variadic argument list.
219+jsonbBuildArray :: SOP.SListI tuple => tuple ---> null 'PGjsonb
220+jsonbBuildArray = unsafeFunctionN "jsonb_build_array"
221+
222+-- | Builds a possibly-heterogeneously-typed JSON object out of a variadic
223+-- argument list. The elements of the argument list must alternate between text
224+-- and values.
225+class SOP.SListI tys => JsonBuildObject tys where
226+
227+ jsonBuildObject :: tys ---> null 'PGjson
228+ jsonBuildObject = unsafeFunctionN "json_build_object"
229+
230+ jsonbBuildObject :: tys ---> null 'PGjsonb
231+ jsonbBuildObject = unsafeFunctionN "jsonb_build_object"
232+
233+instance JsonBuildObject '[]
234+instance (JsonBuildObject tys, key `In` PGJsonKey)
235+ => JsonBuildObject ('NotNull key ': value ': tys)
236+
237+-- | Builds a JSON object out of a text array.
238+-- The array must have two dimensions
239+-- such that each inner array has exactly two elements,
240+-- which are taken as a key/value pair.
241+jsonObject
242+ :: null ('PGfixarray '[n,2] ('NotNull 'PGtext))
243+ --> null 'PGjson
244+jsonObject = unsafeFunction "json_object"
245+
246+-- | Builds a binary JSON object out of a text array.
247+-- The array must have two dimensions
248+-- such that each inner array has exactly two elements,
249+-- which are taken as a key/value pair.
250+jsonbObject
251+ :: null ('PGfixarray '[n,2] ('NotNull 'PGtext))
252+ --> null 'PGjsonb
253+jsonbObject = unsafeFunction "jsonb_object"
254+
255+-- | This is an alternate form of 'jsonObject' that takes two arrays; one for
256+-- keys and one for values, that are zipped pairwise to create a JSON object.
257+jsonZipObject ::
258+ '[ null ('PGvararray ('NotNull 'PGtext))
259+ , null ('PGvararray ('NotNull 'PGtext)) ]
260+ ---> null 'PGjson
261+jsonZipObject = unsafeFunctionN "json_object"
262+
263+-- | This is an alternate form of 'jsonbObject' that takes two arrays; one for
264+-- keys and one for values, that are zipped pairwise to create a binary JSON
265+-- object.
266+jsonbZipObject ::
267+ '[ null ('PGvararray ('NotNull 'PGtext))
268+ , null ('PGvararray ('NotNull 'PGtext)) ]
269+ ---> null 'PGjsonb
270+jsonbZipObject = unsafeFunctionN "jsonb_object"
271+
272+{-----------------------------------------
273+Table 9.46: JSON processing functions
274+-----------------------------------------}
275+
276+-- | Returns the number of elements in the outermost JSON array.
277+jsonArrayLength :: null 'PGjson --> null 'PGint4
278+jsonArrayLength = unsafeFunction "json_array_length"
279+
280+-- | Returns the number of elements in the outermost binary JSON array.
281+jsonbArrayLength :: null 'PGjsonb --> null 'PGint4
282+jsonbArrayLength = unsafeFunction "jsonb_array_length"
283+
284+-- | Returns the type of the outermost JSON value as a text string. Possible
285+-- types are object, array, string, number, boolean, and null.
286+jsonTypeof :: null 'PGjson --> null 'PGtext
287+jsonTypeof = unsafeFunction "json_typeof"
288+
289+-- | Returns the type of the outermost binary JSON value as a text string.
290+-- Possible types are object, array, string, number, boolean, and null.
291+jsonbTypeof :: null 'PGjsonb --> null 'PGtext
292+jsonbTypeof = unsafeFunction "jsonb_typeof"
293+
294+-- | Returns its argument with all object fields that have null values omitted.
295+-- Other null values are untouched.
296+jsonStripNulls :: null 'PGjson --> null 'PGjson
297+jsonStripNulls = unsafeFunction "json_strip_nulls"
298+
299+-- | Returns its argument with all object fields that have null values omitted.
300+-- Other null values are untouched.
301+jsonbStripNulls :: null 'PGjsonb --> null 'PGjsonb
302+jsonbStripNulls = unsafeFunction "jsonb_strip_nulls"
303+
304+-- | @ jsonbSet target path new_value create_missing @
305+--
306+-- Returns target with the section designated by path replaced by @new_value@,
307+-- or with @new_value@ added if create_missing is
308+-- `Squeal.PostgreSQL.Expression.Logic.true` and the
309+-- item designated by path does not exist. As with the path orientated
310+-- operators, negative integers that appear in path count from the end of JSON
311+-- arrays.
312+jsonbSet ::
313+ '[ null 'PGjsonb, null ('PGvararray ('NotNull 'PGtext))
314+ , null 'PGjsonb, null 'PGbool ] ---> null 'PGjsonb
315+jsonbSet = unsafeFunctionN "jsonbSet"
316+
317+-- | @ jsonbInsert target path new_value insert_after @
318+--
319+-- Returns target with @new_value@ inserted. If target section designated by
320+-- path is in a JSONB array, @new_value@ will be inserted before target or after
321+-- if @insert_after@ is `Squeal.PostgreSQL.Expression.Logic.true`.
322+-- If target section designated by
323+-- path is in JSONB object, @new_value@ will be inserted only if target does not
324+-- exist. As with the path orientated operators, negative integers that appear
325+-- in path count from the end of JSON arrays.
326+jsonbInsert ::
327+ '[ null 'PGjsonb, null ('PGvararray ('NotNull 'PGtext))
328+ , null 'PGjsonb, null 'PGbool ] ---> null 'PGjsonb
329+jsonbInsert = unsafeFunctionN "jsonb_insert"
330+
331+-- | Returns its argument as indented JSON text.
332+jsonbPretty :: null 'PGjsonb --> null 'PGtext
333+jsonbPretty = unsafeFunction "jsonb_pretty"
334+
335+{- | Expands the outermost JSON object into a set of key/value pairs.
336+
337+>>> printSQL (select Star (from (jsonEach (literal (Json (object ["a" .= "foo", "b" .= "bar"]))))))
338+SELECT * FROM json_each(('{"a":"foo","b":"bar"}' :: json))
339+-}
340+jsonEach :: SetFunction "json_each" (null 'PGjson)
341+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGjson]
342+jsonEach = unsafeSetFunction
343+
344+{- | Expands the outermost binary JSON object into a set of key/value pairs.
345+
346+>>> printSQL (select Star (from (jsonbEach (literal (Jsonb (object ["a" .= "foo", "b" .= "bar"]))))))
347+SELECT * FROM jsonb_each(('{"a":"foo","b":"bar"}' :: jsonb))
348+-}
349+jsonbEach
350+ :: SetFunction "jsonb_each" (nullity 'PGjsonb)
351+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGjson]
352+jsonbEach = unsafeSetFunction
353+
354+{- | Expands the outermost JSON object into a set of key/value pairs.
355+
356+>>> printSQL (select Star (from (jsonEachText (literal (Json (object ["a" .= "foo", "b" .= "bar"]))))))
357+SELECT * FROM json_each_text(('{"a":"foo","b":"bar"}' :: json))
358+-}
359+jsonEachText
360+ :: SetFunction "json_each_text" (null 'PGjson)
361+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGtext]
362+jsonEachText = unsafeSetFunction
363+
364+{- | Expands the outermost binary JSON object into a set of key/value pairs.
365+
366+>>> printSQL (select Star (from (jsonbEachText (literal (Jsonb (object ["a" .= "foo", "b" .= "bar"]))))))
367+SELECT * FROM jsonb_each_text(('{"a":"foo","b":"bar"}' :: jsonb))
368+-}
369+jsonbEachText
370+ :: SetFunction "jsonb_each_text" (null 'PGjsonb)
371+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGtext]
372+jsonbEachText = unsafeSetFunction
373+
374+{- | Returns set of keys in the outermost JSON object.
375+
376+>>> printSQL (jsonObjectKeys (literal (Json (object ["a" .= "foo", "b" .= "bar"]))))
377+json_object_keys(('{"a":"foo","b":"bar"}' :: json))
378+-}
379+jsonObjectKeys
380+ :: SetFunction "json_object_keys" (nullity 'PGjson)
381+ '["json_object_keys" ::: 'NotNull 'PGtext]
382+jsonObjectKeys = unsafeSetFunction
383+
384+{- | Returns set of keys in the outermost JSON object.
385+
386+>>> printSQL (jsonbObjectKeys (literal (Jsonb (object ["a" .= "foo", "b" .= "bar"]))))
387+jsonb_object_keys(('{"a":"foo","b":"bar"}' :: jsonb))
388+-}
389+jsonbObjectKeys
390+ :: SetFunction "jsonb_object_keys" (null 'PGjsonb)
391+ '["jsonb_object_keys" ::: 'NotNull 'PGtext]
392+jsonbObjectKeys = unsafeSetFunction
393+
394+-- | Build rows from Json types.
395+type JsonPopulateFunction fun json
396+ = forall schemas row outer commons params
397+ . json `In` PGJsonType
398+ => TypeExpression schemas ('NotNull ('PGcomposite row)) -- ^ row type
399+ -> Expression outer commons 'Ungrouped schemas params '[] ('NotNull json)
400+ -- ^ json type
401+ -> FromClause outer commons schemas params '[fun ::: row]
402+
403+unsafePopulateFunction
404+ :: forall fun ty
405+ . KnownSymbol fun => Alias fun -> JsonPopulateFunction fun ty
406+unsafePopulateFunction _fun ty expr = UnsafeFromClause $ renderSymbol @fun
407+ <> parenthesized ("null::" <> renderSQL ty <> ", " <> renderSQL expr)
408+
409+-- | Expands the JSON expression to a row whose columns match the record
410+-- type defined by the given table.
411+jsonPopulateRecord :: JsonPopulateFunction "json_populate_record" 'PGjson
412+jsonPopulateRecord = unsafePopulateFunction #json_populate_record
413+
414+-- | Expands the binary JSON expression to a row whose columns match the record
415+-- type defined by the given table.
416+jsonbPopulateRecord :: JsonPopulateFunction "jsonb_populate_record" 'PGjsonb
417+jsonbPopulateRecord = unsafePopulateFunction #jsonb_populate_record
418+
419+-- | Expands the outermost array of objects in the given JSON expression to a
420+-- set of rows whose columns match the record type defined by the given table.
421+jsonPopulateRecordSet :: JsonPopulateFunction "json_populate_record_set" 'PGjson
422+jsonPopulateRecordSet = unsafePopulateFunction #json_populate_record_set
423+
424+-- | Expands the outermost array of objects in the given binary JSON expression
425+-- to a set of rows whose columns match the record type defined by the given
426+-- table.
427+jsonbPopulateRecordSet :: JsonPopulateFunction "jsonb_populate_record_set" 'PGjsonb
428+jsonbPopulateRecordSet = unsafePopulateFunction #jsonb_populate_record_set
429+
430+-- | Build rows from Json types.
431+type JsonToRecordFunction json
432+ = forall outer commons schemas params tab row
433+ . (SOP.SListI row, json `In` PGJsonType)
434+ => Expression outer commons 'Ungrouped schemas params '[] ('NotNull json)
435+ -- ^ json type
436+ -> Aliased (NP (Aliased (TypeExpression schemas))) (tab ::: row)
437+ -- ^ row type
438+ -> FromClause outer commons schemas params '[tab ::: row]
439+
440+unsafeRecordFunction :: ByteString -> JsonToRecordFunction json
441+unsafeRecordFunction fun expr (types `As` tab) = UnsafeFromClause $
442+ fun <> parenthesized (renderSQL expr) <+> "AS" <+> renderSQL tab
443+ <> parenthesized (renderCommaSeparated renderTy types)
444+ where
445+ renderTy :: Aliased (TypeExpression schemas) ty -> ByteString
446+ renderTy (ty `As` alias) = renderSQL alias <+> renderSQL ty
447+
448+-- | Builds an arbitrary record from a JSON object.
449+jsonToRecord :: JsonToRecordFunction 'PGjson
450+jsonToRecord = unsafeRecordFunction "json_to_record"
451+
452+-- | Builds an arbitrary record from a binary JSON object.
453+jsonbToRecord :: JsonToRecordFunction 'PGjsonb
454+jsonbToRecord = unsafeRecordFunction "jsonb_to_record"
455+
456+-- | Builds an arbitrary set of records from a JSON array of objects.
457+jsonToRecordSet :: JsonToRecordFunction 'PGjson
458+jsonToRecordSet = unsafeRecordFunction "json_to_record_set"
459+
460+-- | Builds an arbitrary set of records from a binary JSON array of objects.
461+jsonbToRecordSet :: JsonToRecordFunction 'PGjsonb
462+jsonbToRecordSet = unsafeRecordFunction "jsonb_to_record_set"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Literal.hsnew file+87
@@ -0,0 +1,87 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Literal
3+Description: Literal expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Literal expressions
9+-}
10+
11+{-# LANGUAGE
12+ FlexibleContexts
13+ , FlexibleInstances
14+ , LambdaCase
15+ , OverloadedStrings
16+ , RankNTypes
17+ , ScopedTypeVariables
18+ , TypeApplications
19+ , TypeSynonymInstances
20+ , UndecidableInstances
21+#-}
22+
23+module Squeal.PostgreSQL.Expression.Literal (Literal (..)) where
24+
25+import ByteString.StrictBuilder (builderBytes)
26+import Data.ByteString.Lazy (toStrict)
27+import Data.Int
28+import Data.String
29+import Data.Text (Text)
30+
31+import qualified Data.Aeson as JSON
32+import qualified Data.Text as Text
33+import qualified Data.Text.Lazy as Lazy (Text)
34+import qualified Data.Text.Lazy as Lazy.Text
35+
36+import Squeal.PostgreSQL.Binary
37+import Squeal.PostgreSQL.Expression
38+import Squeal.PostgreSQL.Expression.Logic
39+import Squeal.PostgreSQL.PG
40+import Squeal.PostgreSQL.Render
41+
42+{- |
43+The `Literal` class allows embedding a Haskell value directly
44+as an `Expression` using `literal`.
45+
46+>>> printSQL (literal 'a')
47+E'a'
48+
49+>>> printSQL (literal (1 :: Double))
50+1.0
51+
52+>>> printSQL (literal (Json [1 :: Double, 2]))
53+('[1.0,2.0]' :: json)
54+
55+>>> printSQL (literal (Enumerated GT))
56+'GT'
57+-}
58+class Literal hask where literal :: hask -> Expr (null (PG hask))
59+instance Literal Bool where
60+ literal = \case
61+ True -> true
62+ False -> false
63+instance JSON.ToJSON hask => Literal (Json hask) where
64+ literal = UnsafeExpression . parenthesized . (<> " :: json")
65+ . singleQuotedUtf8 . toStrict . JSON.encode . getJson
66+instance JSON.ToJSON hask => Literal (Jsonb hask) where
67+ literal = UnsafeExpression . parenthesized . (<> " :: jsonb")
68+ . singleQuotedUtf8 . toStrict . JSON.encode . getJsonb
69+instance Literal Char where
70+ literal chr = UnsafeExpression $
71+ "E\'" <> fromString (escape chr) <> "\'"
72+instance Literal String where literal = fromString
73+instance Literal Int16 where literal = fromIntegral
74+instance Literal Int32 where literal = fromIntegral
75+instance Literal Int64 where literal = fromIntegral
76+instance Literal Float where literal = fromRational . toRational
77+instance Literal Double where literal = fromRational . toRational
78+instance Literal Text where literal = fromString . Text.unpack
79+instance Literal Lazy.Text where literal = fromString . Lazy.Text.unpack
80+instance ToParam (Enumerated enum) (PG (Enumerated enum))
81+ => Literal (Enumerated enum) where
82+ literal
83+ = UnsafeExpression
84+ . singleQuotedUtf8
85+ . builderBytes
86+ . unK
87+ . toParam @(Enumerated enum) @(PG (Enumerated enum))
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Logic.hsnew file+105
@@ -0,0 +1,105 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Logic
3+Description: Logical expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Logical expressions and operators
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , OverloadedStrings
14+ , TypeOperators
15+#-}
16+
17+module Squeal.PostgreSQL.Expression.Logic
18+ ( Condition
19+ , true
20+ , false
21+ , not_
22+ , (.&&)
23+ , (.||)
24+ , caseWhenThenElse
25+ , ifThenElse
26+ ) where
27+
28+import Squeal.PostgreSQL.Expression
29+import Squeal.PostgreSQL.Render
30+import Squeal.PostgreSQL.Schema
31+
32+-- | A `Condition` is an `Expression`, which can evaluate
33+-- to `true`, `false` or `Squeal.PostgreSQL.Null.null_`. This is because SQL uses
34+-- a three valued logic.
35+type Condition outer commons grp schemas params from =
36+ Expression outer commons grp schemas params from ('Null 'PGbool)
37+
38+-- | >>> printSQL true
39+-- TRUE
40+true :: Expr (null 'PGbool)
41+true = UnsafeExpression "TRUE"
42+
43+-- | >>> printSQL false
44+-- FALSE
45+false :: Expr (null 'PGbool)
46+false = UnsafeExpression "FALSE"
47+
48+-- | >>> printSQL $ not_ true
49+-- (NOT TRUE)
50+not_ :: null 'PGbool --> null 'PGbool
51+not_ = unsafeLeftOp "NOT"
52+
53+-- | >>> printSQL $ true .&& false
54+-- (TRUE AND FALSE)
55+(.&&) :: Operator (null 'PGbool) (null 'PGbool) (null 'PGbool)
56+infixr 3 .&&
57+(.&&) = unsafeBinaryOp "AND"
58+
59+-- | >>> printSQL $ true .|| false
60+-- (TRUE OR FALSE)
61+(.||) :: Operator (null 'PGbool) (null 'PGbool) (null 'PGbool)
62+infixr 2 .||
63+(.||) = unsafeBinaryOp "OR"
64+
65+-- | >>> :{
66+-- let
67+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)
68+-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3
69+-- in printSQL expression
70+-- :}
71+-- CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END
72+caseWhenThenElse
73+ :: [ ( Condition outer commons grp schemas params from
74+ , Expression outer commons grp schemas params from ty
75+ ) ]
76+ -- ^ whens and thens
77+ -> Expression outer commons grp schemas params from ty
78+ -- ^ else
79+ -> Expression outer commons grp schemas params from ty
80+caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat
81+ [ "CASE"
82+ , mconcat
83+ [ mconcat
84+ [ " WHEN ", renderSQL when_
85+ , " THEN ", renderSQL then_
86+ ]
87+ | (when_,then_) <- whenThens
88+ ]
89+ , " ELSE ", renderSQL else_
90+ , " END"
91+ ]
92+
93+-- | >>> :{
94+-- let
95+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)
96+-- expression = ifThenElse true 1 0
97+-- in printSQL expression
98+-- :}
99+-- CASE WHEN TRUE THEN 1 ELSE 0 END
100+ifThenElse
101+ :: Condition outer commons grp schemas params from
102+ -> Expression outer commons grp schemas params from ty -- ^ then
103+ -> Expression outer commons grp schemas params from ty -- ^ else
104+ -> Expression outer commons grp schemas params from ty
105+ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Math.hsnew file+100
@@ -0,0 +1,100 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Math
3+Description: Math expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Mathematical functions and operators
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , OverloadedStrings
14+ , TypeOperators
15+#-}
16+
17+module Squeal.PostgreSQL.Expression.Math
18+ ( atan2_
19+ , quot_
20+ , rem_
21+ , trunc
22+ , round_
23+ , ceiling_
24+ ) where
25+
26+import Squeal.PostgreSQL.Expression
27+import Squeal.PostgreSQL.List
28+import Squeal.PostgreSQL.Schema
29+
30+-- $setup
31+-- >>> import Squeal.PostgreSQL
32+
33+-- | >>> :{
34+-- let
35+-- expression :: Expr (null 'PGfloat4)
36+-- expression = atan2_ (pi *: 2)
37+-- in printSQL expression
38+-- :}
39+-- atan2(pi(), 2)
40+atan2_ :: float `In` PGFloating => '[ null float, null float] ---> null float
41+atan2_ = unsafeFunctionN "atan2"
42+
43+
44+-- | integer division, truncates the result
45+--
46+-- >>> :{
47+-- let
48+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)
49+-- expression = 5 `quot_` 2
50+-- in printSQL expression
51+-- :}
52+-- (5 / 2)
53+quot_
54+ :: int `In` PGIntegral
55+ => Operator (null int) (null int) (null int)
56+quot_ = unsafeBinaryOp "/"
57+
58+-- | remainder upon integer division
59+--
60+-- >>> :{
61+-- let
62+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)
63+-- expression = 5 `rem_` 2
64+-- in printSQL expression
65+-- :}
66+-- (5 % 2)
67+rem_
68+ :: int `In` PGIntegral
69+ => Operator (null int) (null int) (null int)
70+rem_ = unsafeBinaryOp "%"
71+
72+-- | >>> :{
73+-- let
74+-- expression :: Expression outer commons grp schemas params from (null 'PGfloat4)
75+-- expression = trunc pi
76+-- in printSQL expression
77+-- :}
78+-- trunc(pi())
79+trunc :: frac `In` PGFloating => null frac --> null frac
80+trunc = unsafeFunction "trunc"
81+
82+-- | >>> :{
83+-- let
84+-- expression :: Expression outer commons grp schemas params from (null 'PGfloat4)
85+-- expression = round_ pi
86+-- in printSQL expression
87+-- :}
88+-- round(pi())
89+round_ :: frac `In` PGFloating => null frac --> null frac
90+round_ = unsafeFunction "round"
91+
92+-- | >>> :{
93+-- let
94+-- expression :: Expression outer commons grp schemas params from (null 'PGfloat4)
95+-- expression = ceiling_ pi
96+-- in printSQL expression
97+-- :}
98+-- ceiling(pi())
99+ceiling_ :: frac `In` PGFloating => null frac --> null frac
100+ceiling_ = unsafeFunction "ceiling"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Null.hsnew file+104
@@ -0,0 +1,104 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Null
3+Description: Null
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Null values and null handling functions
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , OverloadedStrings
14+ , TypeOperators
15+#-}
16+
17+module Squeal.PostgreSQL.Expression.Null
18+ ( null_
19+ , notNull
20+ , coalesce
21+ , fromNull
22+ , isNull
23+ , isNotNull
24+ , matchNull
25+ , nullIf
26+ ) where
27+
28+import Squeal.PostgreSQL.Expression
29+import Squeal.PostgreSQL.Expression.Logic
30+import Squeal.PostgreSQL.Render
31+import Squeal.PostgreSQL.Schema
32+
33+-- $setup
34+-- >>> import Squeal.PostgreSQL
35+
36+-- | analagous to `Nothing`
37+--
38+-- >>> printSQL null_
39+-- NULL
40+null_ :: Expr ('Null ty)
41+null_ = UnsafeExpression "NULL"
42+
43+-- | analagous to `Just`
44+--
45+-- >>> printSQL $ notNull true
46+-- TRUE
47+notNull :: 'NotNull ty --> 'Null ty
48+notNull = UnsafeExpression . renderSQL
49+
50+-- | return the leftmost value which is not NULL
51+--
52+-- >>> printSQL $ coalesce [null_, true] false
53+-- COALESCE(NULL, TRUE, FALSE)
54+coalesce :: FunctionVar ('Null ty) ('NotNull ty) ('NotNull ty)
55+coalesce nullxs notNullx = UnsafeExpression $
56+ "COALESCE" <> parenthesized (commaSeparated
57+ ((renderSQL <$> nullxs) <> [renderSQL notNullx]))
58+
59+-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@
60+--
61+-- >>> printSQL $ fromNull true null_
62+-- COALESCE(NULL, TRUE)
63+fromNull
64+ :: Expression outer commons grp schemas params from ('NotNull ty)
65+ -- ^ what to convert @NULL@ to
66+ -> Expression outer commons grp schemas params from ('Null ty)
67+ -> Expression outer commons grp schemas params from ('NotNull ty)
68+fromNull notNullx nullx = coalesce [nullx] notNullx
69+
70+-- | >>> printSQL $ null_ & isNull
71+-- NULL IS NULL
72+isNull :: 'Null ty --> null 'PGbool
73+isNull x = UnsafeExpression $ renderSQL x <+> "IS NULL"
74+
75+-- | >>> printSQL $ null_ & isNotNull
76+-- NULL IS NOT NULL
77+isNotNull :: 'Null ty --> null 'PGbool
78+isNotNull x = UnsafeExpression $ renderSQL x <+> "IS NOT NULL"
79+
80+-- | analagous to `maybe` using @IS NULL@
81+--
82+-- >>> printSQL $ matchNull true not_ null_
83+-- CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END
84+matchNull
85+ :: Expression outer commons grp schemas params from (nullty)
86+ -- ^ what to convert @NULL@ to
87+ -> ( Expression outer commons grp schemas params from ('NotNull ty)
88+ -> Expression outer commons grp schemas params from (nullty) )
89+ -- ^ function to perform when @NULL@ is absent
90+ -> Expression outer commons grp schemas params from ('Null ty)
91+ -> Expression outer commons grp schemas params from (nullty)
92+matchNull y f x = ifThenElse (isNull x) y
93+ (f (UnsafeExpression (renderSQL x)))
94+
95+{-| right inverse to `fromNull`, if its arguments are equal then
96+`nullIf` gives @NULL@.
97+
98+>>> :set -XTypeApplications -XDataKinds
99+>>> let expr = nullIf (false *: param @1) :: Expression outer commons grp schemas '[ 'NotNull 'PGbool] from ('Null 'PGbool)
100+>>> printSQL expr
101+NULLIF(FALSE, ($1 :: bool))
102+-}
103+nullIf :: '[ 'NotNull ty, 'NotNull ty] ---> 'Null ty
104+nullIf = unsafeFunctionN "NULLIF"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Parameter.hsnew file+80
@@ -0,0 +1,80 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Parameter
3+Description: Parameters
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Parameters, out-of-line data values
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , DataKinds
14+ , FlexibleContexts
15+ , FlexibleInstances
16+ , FunctionalDependencies
17+ , KindSignatures
18+ , MultiParamTypeClasses
19+ , OverloadedStrings
20+ , RankNTypes
21+ , ScopedTypeVariables
22+ , TypeApplications
23+ , TypeOperators
24+ , UndecidableInstances
25+#-}
26+
27+module Squeal.PostgreSQL.Expression.Parameter
28+ ( HasParameter (parameter)
29+ , param
30+ ) where
31+
32+import GHC.TypeLits
33+
34+import Squeal.PostgreSQL.Expression
35+import Squeal.PostgreSQL.Expression.Type
36+import Squeal.PostgreSQL.Render
37+import Squeal.PostgreSQL.Schema
38+
39+-- $setup
40+-- >>> import Squeal.PostgreSQL
41+
42+{- | A `HasParameter` constraint is used to indicate a value that is
43+supplied externally to a SQL statement.
44+`Squeal.PostgreSQL.PQ.manipulateParams`,
45+`Squeal.PostgreSQL.PQ.queryParams` and
46+`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values
47+separately from the SQL command string, in which case `param`s are used to
48+refer to the out-of-line data values.
49+-}
50+class KnownNat n => HasParameter
51+ (n :: Nat)
52+ (params :: [NullityType])
53+ (ty :: NullityType)
54+ | n params -> ty where
55+ -- | `parameter` takes a `Nat` using type application and a `TypeExpression`.
56+ --
57+ -- >>> let expr = parameter @1 int4 :: Expression outer '[] grp schemas '[ 'Null 'PGint4] from ('Null 'PGint4)
58+ -- >>> printSQL expr
59+ -- ($1 :: int4)
60+ parameter
61+ :: TypeExpression schemas ty
62+ -> Expression outer commons grp schemas params from ty
63+ parameter ty = UnsafeExpression $ parenthesized $
64+ "$" <> renderNat @n <+> "::"
65+ <+> renderSQL ty
66+instance {-# OVERLAPPING #-} HasParameter 1 (ty1:tys) ty1
67+instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) params ty)
68+ => HasParameter n (ty' : params) ty
69+
70+-- | `param` takes a `Nat` using type application and for basic types,
71+-- infers a `TypeExpression`.
72+--
73+-- >>> let expr = param @1 :: Expression outer commons grp schemas '[ 'Null 'PGint4] from ('Null 'PGint4)
74+-- >>> printSQL expr
75+-- ($1 :: int4)
76+param
77+ :: forall n outer commons schemas params from grp ty
78+ . (PGTyped schemas ty, HasParameter n params ty)
79+ => Expression outer commons grp schemas params from ty -- ^ param
80+param = parameter @n (pgtype @schemas)
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Range.hsnew file+230
@@ -0,0 +1,230 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Range
3+Description: range types and functions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Range types and functions
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , DataKinds
14+ , DeriveAnyClass
15+ , DeriveGeneric
16+ , DeriveFoldable
17+ , DerivingStrategies
18+ , DeriveTraversable
19+ , FlexibleContexts
20+ , FlexibleInstances
21+ , LambdaCase
22+ , MultiParamTypeClasses
23+ , OverloadedLabels
24+ , OverloadedStrings
25+ , PatternSynonyms
26+ , RankNTypes
27+ , ScopedTypeVariables
28+ , TypeApplications
29+ , TypeFamilies
30+ , TypeOperators
31+ , UndecidableInstances
32+#-}
33+
34+module Squeal.PostgreSQL.Expression.Range
35+ ( range
36+ , Range (..)
37+ , (<=..<=), (<..<), (<=..<), (<..<=)
38+ , moreThan, atLeast, lessThan, atMost
39+ , singleton, whole
40+ , Bound (..)
41+ , (.<@)
42+ , (@>.)
43+ , (<<@)
44+ , (@>>)
45+ , (&<)
46+ , (&>)
47+ , (-|-)
48+ , (@+)
49+ , (@*)
50+ , (@-)
51+ , lowerBound
52+ , upperBound
53+ , isEmpty
54+ , lowerInc
55+ , lowerInf
56+ , upperInc
57+ , upperInf
58+ , rangeMerge
59+ ) where
60+
61+import BinaryParser
62+import ByteString.StrictBuilder
63+import Data.Bits
64+import qualified GHC.Generics as GHC
65+import qualified Generics.SOP as SOP
66+import qualified PostgreSQL.Binary.Decoding as Decoding
67+
68+import Squeal.PostgreSQL.Binary
69+import Squeal.PostgreSQL.Expression
70+import Squeal.PostgreSQL.Expression.Type hiding (bool)
71+import Squeal.PostgreSQL.PG
72+import Squeal.PostgreSQL.Render
73+import Squeal.PostgreSQL.Schema
74+
75+-- $setup
76+-- >>> import Squeal.PostgreSQL
77+
78+-- | Construct a `range`
79+--
80+-- >>> printSQL $ range tstzrange (atLeast now)
81+-- tstzrange(now(), NULL, '[)')
82+-- >>> printSQL $ range numrange (0 <=..< 2*pi)
83+-- numrange(0, (2 * pi()), '[)')
84+-- >>> printSQL $ range int4range Empty
85+-- ('empty' :: int4range)
86+range
87+ :: TypeExpression schemas (null ('PGrange ty))
88+ -> Range (Expression outer commons grp schemas params from ('NotNull ty))
89+ -> Expression outer commons grp schemas params from (null ('PGrange ty))
90+range ty = \case
91+ Empty -> UnsafeExpression $ parenthesized
92+ (emp <+> "::" <+> renderSQL ty)
93+ NonEmpty l u -> UnsafeExpression $ renderSQL ty <> parenthesized
94+ (commaSeparated (args l u))
95+ where
96+ emp = singleQuote <> "empty" <> singleQuote
97+ args l u = [arg l, arg u, singleQuote <> bra l <> ket u <> singleQuote]
98+ singleQuote = "\'"
99+ arg = \case
100+ Infinite -> "NULL"; Closed x -> renderSQL x; Open x -> renderSQL x
101+ bra = \case Infinite -> "("; Closed _ -> "["; Open _ -> "("
102+ ket = \case Infinite -> ")"; Closed _ -> "]"; Open _ -> ")"
103+
104+data Bound x = Infinite | Closed x | Open x
105+ deriving
106+ ( Eq, Ord, Show, Read, GHC.Generic
107+ , Functor, Foldable, Traversable )
108+
109+data Range x = Empty | NonEmpty (Bound x) (Bound x)
110+ deriving
111+ ( Eq, Ord, Show, Read, GHC.Generic
112+ , Functor, Foldable, Traversable )
113+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
114+type instance PG (Range x) = 'PGrange (PG x)
115+instance ToParam x pg => ToParam (Range x) ('PGrange pg) where
116+ toParam rng = K $
117+ word8 (setFlags rng 0) <>
118+ case rng of
119+ Empty -> mempty
120+ NonEmpty lower upper -> putBound lower <> putBound upper
121+ where
122+ putBound = \case
123+ Infinite -> mempty
124+ Closed value -> putValue (unK (toParam @x @pg value))
125+ Open value -> putValue (unK (toParam @x @pg value))
126+ putValue value = int32BE (fromIntegral (builderLength value)) <> value
127+ setFlags = \case
128+ Empty -> (`setBit` 0)
129+ NonEmpty lower upper ->
130+ setLowerFlags lower . setUpperFlags upper
131+ setLowerFlags = \case
132+ Infinite -> (`setBit` 3)
133+ Closed _ -> (`setBit` 1)
134+ Open _ -> id
135+ setUpperFlags = \case
136+ Infinite -> (`setBit` 4)
137+ Closed _ -> (`setBit` 2)
138+ Open _ -> id
139+instance FromValue pg y => FromValue ('PGrange pg) (Range y) where
140+ fromValue = do
141+ flag <- byte
142+ if testBit flag 0 then return Empty else do
143+ lower <-
144+ if testBit flag 3
145+ then return Infinite
146+ else do
147+ len <- sized 4 Decoding.int
148+ l <- sized len (fromValue @pg)
149+ return $ if testBit flag 1 then Closed l else Open l
150+ upper <-
151+ if testBit flag 4
152+ then return Infinite
153+ else do
154+ len <- sized 4 Decoding.int
155+ l <- sized len (fromValue @pg)
156+ return $ if testBit flag 2 then Closed l else Open l
157+ return $ NonEmpty lower upper
158+
159+(<=..<=), (<..<), (<=..<), (<..<=) :: x -> x -> Range x
160+infix 4 <=..<=, <..<, <=..<, <..<=
161+x <=..<= y = NonEmpty (Closed x) (Closed y)
162+x <..< y = NonEmpty (Open x) (Open y)
163+x <=..< y = NonEmpty (Closed x) (Open y)
164+x <..<= y = NonEmpty (Open x) (Closed y)
165+
166+moreThan, atLeast, lessThan, atMost :: x -> Range x
167+moreThan x = NonEmpty (Open x) Infinite
168+atLeast x = NonEmpty (Closed x) Infinite
169+lessThan x = NonEmpty Infinite (Open x)
170+atMost x = NonEmpty Infinite (Closed x)
171+
172+singleton :: x -> Range x
173+singleton x = x <=..<= x
174+
175+whole :: Range x
176+whole = NonEmpty Infinite Infinite
177+
178+(.<@) :: Operator ('NotNull ty) (null ('PGrange ty)) ('Null 'PGbool)
179+(.<@) = unsafeBinaryOp "<@"
180+
181+(@>.) :: Operator (null ('PGrange ty)) ('NotNull ty) ('Null 'PGbool)
182+(@>.) = unsafeBinaryOp "<@"
183+
184+(<<@) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)
185+(<<@) = unsafeBinaryOp "<<"
186+
187+(@>>) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)
188+(@>>) = unsafeBinaryOp ">>"
189+
190+(&<) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)
191+(&<) = unsafeBinaryOp "&<"
192+
193+(&>) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)
194+(&>) = unsafeBinaryOp "&>"
195+
196+(-|-) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)
197+(-|-) = unsafeBinaryOp "-|-"
198+
199+(@+) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) (null ('PGrange ty))
200+(@+) = unsafeBinaryOp "+"
201+
202+(@*) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) (null ('PGrange ty))
203+(@*) = unsafeBinaryOp "*"
204+
205+(@-) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) (null ('PGrange ty))
206+(@-) = unsafeBinaryOp "-"
207+
208+lowerBound :: null ('PGrange ty) --> 'Null ty
209+lowerBound = unsafeFunction "lower"
210+
211+upperBound :: null ('PGrange ty) --> 'Null ty
212+upperBound = unsafeFunction "upper"
213+
214+isEmpty :: null ('PGrange ty) --> 'Null 'PGbool
215+isEmpty = unsafeFunction "isempty"
216+
217+lowerInc :: null ('PGrange ty) --> 'Null 'PGbool
218+lowerInc = unsafeFunction "lower_inc"
219+
220+lowerInf :: null ('PGrange ty) --> 'Null 'PGbool
221+lowerInf = unsafeFunction "lower_inf"
222+
223+upperInc :: null ('PGrange ty) --> 'Null 'PGbool
224+upperInc = unsafeFunction "upper_inc"
225+
226+upperInf :: null ('PGrange ty) --> 'Null 'PGbool
227+upperInf = unsafeFunction "upper_inf"
228+
229+rangeMerge :: '[null ('PGrange ty), null ('PGrange ty)] ---> null ('PGrange ty)
230+rangeMerge = unsafeFunctionN "range_merge"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Set.hsnew file+139
@@ -0,0 +1,139 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Set
3+Description: Set returning functions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Set returning functions
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , DataKinds
14+ , FlexibleContexts
15+ , OverloadedStrings
16+ , PolyKinds
17+ , RankNTypes
18+ , ScopedTypeVariables
19+ , TypeApplications
20+ , TypeOperators
21+#-}
22+
23+module Squeal.PostgreSQL.Expression.Set
24+ ( generateSeries
25+ , generateSeriesStep
26+ , generateSeriesTimestamp
27+ , SetFunction
28+ , unsafeSetFunction
29+ , SetFunctionDB
30+ , setFunction
31+ , SetFunctionN
32+ , unsafeSetFunctionN
33+ , SetFunctionNDB
34+ , setFunctionN
35+ ) where
36+
37+import GHC.TypeLits
38+
39+import qualified Generics.SOP as SOP
40+
41+import Squeal.PostgreSQL.Alias
42+import Squeal.PostgreSQL.Expression
43+import Squeal.PostgreSQL.List
44+import Squeal.PostgreSQL.Render
45+import Squeal.PostgreSQL.Query
46+import Squeal.PostgreSQL.Schema
47+
48+{- |
49+A @RankNType@ for set returning functions with 1 argument.
50+-}
51+type SetFunction fun ty row
52+ = forall outer commons schemas params
53+ . Expression outer commons 'Ungrouped schemas params '[] ty
54+ -- ^ input
55+ -> FromClause outer commons schemas params '[fun ::: row]
56+ -- ^ output
57+
58+type SetFunctionDB fun schemas ty row
59+ = forall outer commons params
60+ . Expression outer commons 'Ungrouped schemas params '[] ty
61+ -- ^ input
62+ -> FromClause outer commons schemas params '[fun ::: row]
63+ -- ^ output
64+
65+-- | Escape hatch for a set returning function with 1 argument.
66+unsafeSetFunction
67+ :: forall fun ty row. KnownSymbol fun
68+ => SetFunction fun ty row -- ^ set returning function
69+unsafeSetFunction x = UnsafeFromClause $
70+ renderSymbol @fun <> parenthesized (renderSQL x)
71+
72+setFunction
73+ :: ( Has sch schemas schema
74+ , Has fun schema ('Function ('[ty] :=> 'ReturnsTable row)) )
75+ => QualifiedAlias sch fun
76+ -> SetFunctionDB fun schemas ty row
77+setFunction _ = unsafeSetFunction
78+
79+{- |
80+A @RankNType@ for set returning functions with multiple argument.
81+-}
82+type SetFunctionN fun tys row
83+ = forall outer commons schemas params
84+ . NP (Expression outer commons 'Ungrouped schemas params '[]) tys
85+ -- ^ inputs
86+ -> FromClause outer commons schemas params '[fun ::: row]
87+ -- ^ output
88+
89+-- | Escape hatch for a set returning function with multiple argument.
90+unsafeSetFunctionN
91+ :: forall fun tys row. (SOP.SListI tys, KnownSymbol fun)
92+ => SetFunctionN fun tys row -- ^ set returning function
93+unsafeSetFunctionN xs = UnsafeFromClause $
94+ renderSymbol @fun <> parenthesized (renderCommaSeparated renderSQL xs)
95+
96+type SetFunctionNDB fun schemas tys row
97+ = forall outer commons params
98+ . NP (Expression outer commons 'Ungrouped schemas params '[]) tys
99+ -- ^ inputs
100+ -> FromClause outer commons schemas params '[fun ::: row]
101+ -- ^ output
102+
103+setFunctionN
104+ :: ( Has sch schemas schema
105+ , Has fun schema ('Function (tys :=> 'ReturnsTable row))
106+ , SOP.SListI tys )
107+ => QualifiedAlias sch fun
108+ -> SetFunctionNDB fun schemas tys row
109+setFunctionN _ = unsafeSetFunctionN
110+
111+{- | @generateSeries (start *: stop)@
112+
113+Generate a series of values, from @start@ to @stop@ with a step size of one
114+-}
115+generateSeries
116+ :: ty `In` '[ 'PGint4, 'PGint8, 'PGnumeric]
117+ => SetFunctionN "generate_series" '[ null ty, null ty]
118+ '["generate_series" ::: null ty] -- ^ set returning function
119+generateSeries = unsafeSetFunctionN
120+
121+{- | @generateSeries (start :* stop *: step)@
122+
123+Generate a series of values, from @start@ to @stop@ with a step size of @step@
124+-}
125+generateSeriesStep
126+ :: ty `In` '[ 'PGint4, 'PGint8, 'PGnumeric]
127+ => SetFunctionN "generate_series" '[null ty, null ty, null ty]
128+ '["generate_series" ::: null ty] -- ^ set returning function
129+generateSeriesStep = unsafeSetFunctionN
130+
131+{- | @generateSeries (start :* stop *: step)@
132+
133+Generate a series of values, from @start@ to @stop@ with a step size of @step@
134+-}
135+generateSeriesTimestamp
136+ :: ty `In` '[ 'PGtimestamp, 'PGtimestamptz]
137+ => SetFunctionN "generate_series" '[null ty, null ty, null 'PGinterval]
138+ '["generate_series" ::: null ty] -- ^ set returning function
139+generateSeriesTimestamp = unsafeSetFunctionN
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Sort.hsnew file+85
@@ -0,0 +1,85 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Sort
3+Description: Sort expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Sort expressions
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , GADTs
14+ , LambdaCase
15+ , OverloadedStrings
16+ , StandaloneDeriving
17+#-}
18+
19+module Squeal.PostgreSQL.Expression.Sort
20+ ( SortExpression (..)
21+ , OrderBy (..)
22+ ) where
23+
24+import Squeal.PostgreSQL.Expression
25+import Squeal.PostgreSQL.Render
26+import Squeal.PostgreSQL.Schema
27+
28+-- | `SortExpression`s are used by `orderBy` to optionally sort the results
29+-- of a `Squeal.PostgreSQL.Query.Query`. `Asc` or `Desc`
30+-- set the sort direction of a `NotNull` result
31+-- column to ascending or descending. Ascending order puts smaller values
32+-- first, where "smaller" is defined in terms of the
33+-- `Squeal.PostgreSQL.Expression.Comparison..<` operator. Similarly,
34+-- descending order is determined with the
35+-- `Squeal.PostgreSQL.Expression.Comparison..>` operator. `AscNullsFirst`,
36+-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to
37+-- determine whether nulls appear before or after non-null values in the sort
38+-- ordering of a `Null` result column.
39+data SortExpression outer commons grp schemas params from where
40+ Asc
41+ :: Expression outer commons grp schemas params from ('NotNull ty)
42+ -> SortExpression outer commons grp schemas params from
43+ Desc
44+ :: Expression outer commons grp schemas params from ('NotNull ty)
45+ -> SortExpression outer commons grp schemas params from
46+ AscNullsFirst
47+ :: Expression outer commons grp schemas params from ('Null ty)
48+ -> SortExpression outer commons grp schemas params from
49+ AscNullsLast
50+ :: Expression outer commons grp schemas params from ('Null ty)
51+ -> SortExpression outer commons grp schemas params from
52+ DescNullsFirst
53+ :: Expression outer commons grp schemas params from ('Null ty)
54+ -> SortExpression outer commons grp schemas params from
55+ DescNullsLast
56+ :: Expression outer commons grp schemas params from ('Null ty)
57+ -> SortExpression outer commons grp schemas params from
58+deriving instance Show (SortExpression outer commons grp schemas params from)
59+instance RenderSQL (SortExpression outer commons grp schemas params from) where
60+ renderSQL = \case
61+ Asc expression -> renderSQL expression <+> "ASC"
62+ Desc expression -> renderSQL expression <+> "DESC"
63+ AscNullsFirst expression -> renderSQL expression
64+ <+> "ASC NULLS FIRST"
65+ DescNullsFirst expression -> renderSQL expression
66+ <+> "DESC NULLS FIRST"
67+ AscNullsLast expression -> renderSQL expression <+> "ASC NULLS LAST"
68+ DescNullsLast expression -> renderSQL expression <+> "DESC NULLS LAST"
69+
70+{- |
71+The `orderBy` clause causes the result rows of a `Squeal.PostgreSQL.Query.TableExpression`
72+to be sorted according to the specified `SortExpression`(s).
73+If two rows are equal according to the leftmost expression,
74+they are compared according to the next expression and so on.
75+If they are equal according to all specified expressions,
76+they are returned in an implementation-dependent order.
77+
78+You can also control the order in which rows are processed by window functions
79+using `orderBy` within `Squeal.PostgreSQL.Query.Over`.
80+-}
81+class OrderBy expr where
82+ orderBy
83+ :: [SortExpression outer commons grp schemas params from]
84+ -> expr outer commons grp schemas params from
85+ -> expr outer commons grp schemas params from
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Subquery.hsnew file+120
@@ -0,0 +1,120 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Subquery
3+Description: Subquery expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Subquery expressions
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , OverloadedStrings
14+ , RankNTypes
15+ , TypeOperators
16+#-}
17+
18+module Squeal.PostgreSQL.Expression.Subquery
19+ ( exists
20+ , in_
21+ , notIn
22+ , subAll
23+ , subAny
24+ ) where
25+
26+import Squeal.PostgreSQL.Alias
27+import Squeal.PostgreSQL.Expression
28+import Squeal.PostgreSQL.Expression.Logic
29+import Squeal.PostgreSQL.List
30+import Squeal.PostgreSQL.Query
31+import Squeal.PostgreSQL.Render
32+import Squeal.PostgreSQL.Schema
33+
34+-- $setup
35+-- >>> import Squeal.PostgreSQL
36+
37+{- |
38+The argument of `exists` is an arbitrary subquery. The subquery is evaluated
39+to determine whether it returns any rows. If it returns at least one row,
40+the result of `exists` is `true`; if the subquery returns no rows,
41+the result of `exists` is `false`.
42+
43+The subquery can refer to variables from the surrounding query,
44+which will act as constants during any one evaluation of the subquery.
45+
46+The subquery will generally only be executed long enough to determine whether
47+at least one row is returned, not all the way to completion.
48+-}
49+exists
50+ :: Query (Join outer from) commons schemas params row
51+ -> Condition outer commons grp schemas params from
52+exists query = UnsafeExpression $ "EXISTS" <+> parenthesized (renderSQL query)
53+
54+{- |
55+The right-hand side is a parenthesized subquery, which must return
56+exactly one column. The left-hand expression is evaluated and compared to each
57+row of the subquery result using the given `Operator`,
58+which must yield a Boolean result. The result of `subAll` is `true`
59+if all rows yield true (including the case where the subquery returns no rows).
60+The result is `false` if any `false` result is found.
61+The result is `Squeal.PostgreSQL.Expression.Null.null_` if
62+ no comparison with a subquery row returns `false`,
63+and at least one comparison returns `Squeal.PostgreSQL.Expression.Null.null_`.
64+
65+>>> printSQL $ subAll true (.==) (values_ (true `as` #foo))
66+(TRUE = ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo")))
67+-}
68+subAll
69+ :: Expression outer commons grp schemas params from ty1 -- ^ expression
70+ -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator
71+ -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery
72+ -> Condition outer commons grp schemas params from
73+subAll expr (?) qry = expr ?
74+ (UnsafeExpression $ "ALL" <+> parenthesized (renderSQL qry))
75+
76+{- |
77+The right-hand side is a parenthesized subquery, which must return exactly one column.
78+The left-hand expression is evaluated and compared to each row of the subquery result
79+using the given `Operator`, which must yield a Boolean result. The result of `subAny` is `true`
80+if any `true` result is obtained. The result is `false` if no true result is found
81+(including the case where the subquery returns no rows).
82+
83+>>> printSQL $ subAny "foo" like (values_ ("foobar" `as` #foo))
84+(E'foo' LIKE ANY (SELECT * FROM (VALUES (E'foobar')) AS t ("foo")))
85+-}
86+subAny
87+ :: Expression outer commons grp schemas params from ty1 -- ^ expression
88+ -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator
89+ -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery
90+ -> Condition outer commons grp schemas params from
91+subAny expr (?) qry = expr ?
92+ (UnsafeExpression $ "ANY" <+> parenthesized (renderSQL qry))
93+
94+{- |
95+The result is `true` if the left-hand expression's result is equal
96+to any of the right-hand expressions.
97+
98+>>> printSQL $ true `in_` [true, false, null_]
99+TRUE IN (TRUE, FALSE, NULL)
100+-}
101+in_
102+ :: Expression outer commons grp schemas params from ty -- ^ expression
103+ -> [Expression outer commons grp schemas params from ty]
104+ -> Condition outer commons grp schemas params from
105+expr `in_` exprs = UnsafeExpression $ renderSQL expr <+> "IN"
106+ <+> parenthesized (commaSeparated (renderSQL <$> exprs))
107+
108+{- |
109+The result is `true` if the left-hand expression's result is not equal
110+to any of the right-hand expressions.
111+
112+>>> printSQL $ true `notIn` [false, null_]
113+TRUE NOT IN (FALSE, NULL)
114+-}
115+notIn
116+ :: Expression outer commons grp schemas params from ty -- ^ expression
117+ -> [Expression outer commons grp schemas params from ty]
118+ -> Condition outer commons grp schemas params from
119+expr `notIn` exprs = UnsafeExpression $ renderSQL expr <+> "NOT IN"
120+ <+> parenthesized (commaSeparated (renderSQL <$> exprs))
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Text.hsnew file+64
@@ -0,0 +1,64 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Text
3+Description: Text expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+String functions and operators
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , OverloadedStrings
14+ , TypeOperators
15+#-}
16+
17+module Squeal.PostgreSQL.Expression.Text
18+ ( lower
19+ , upper
20+ , charLength
21+ , like
22+ , ilike
23+ ) where
24+
25+import Squeal.PostgreSQL.Expression
26+import Squeal.PostgreSQL.Schema
27+
28+-- $setup
29+-- >>> import Squeal.PostgreSQL
30+
31+-- | >>> printSQL $ lower "ARRRGGG"
32+-- lower(E'ARRRGGG')
33+lower :: null 'PGtext --> null 'PGtext
34+lower = unsafeFunction "lower"
35+
36+-- | >>> printSQL $ upper "eeee"
37+-- upper(E'eeee')
38+upper :: null 'PGtext --> null 'PGtext
39+upper = unsafeFunction "upper"
40+
41+-- | >>> printSQL $ charLength "four"
42+-- char_length(E'four')
43+charLength :: null 'PGtext --> null 'PGint4
44+charLength = unsafeFunction "char_length"
45+
46+-- | The `like` expression returns true if the @string@ matches
47+-- the supplied @pattern@. If @pattern@ does not contain percent signs
48+-- or underscores, then the pattern only represents the string itself;
49+-- in that case `like` acts like the equals operator. An underscore (_)
50+-- in pattern stands for (matches) any single character; a percent sign (%)
51+-- matches any sequence of zero or more characters.
52+--
53+-- >>> printSQL $ "abc" `like` "a%"
54+-- (E'abc' LIKE E'a%')
55+like :: Operator (null 'PGtext) (null 'PGtext) ('Null 'PGbool)
56+like = unsafeBinaryOp "LIKE"
57+
58+-- | The key word ILIKE can be used instead of LIKE to make the
59+-- match case-insensitive according to the active locale.
60+--
61+-- >>> printSQL $ "abc" `ilike` "a%"
62+-- (E'abc' ILIKE E'a%')
63+ilike :: Operator (null 'PGtext) (null 'PGtext) ('Null 'PGbool)
64+ilike = unsafeBinaryOp "ILIKE"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/TextSearch.hsnew file+157
@@ -0,0 +1,157 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.TextSearch
3+Description: Text search expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Text search functions and operators
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , OverloadedStrings
14+ , TypeOperators
15+#-}
16+
17+module Squeal.PostgreSQL.Expression.TextSearch
18+ ( (@@)
19+ , (.&)
20+ , (.|)
21+ , (.!)
22+ , (<->)
23+ , arrayToTSvector
24+ , tsvectorLength
25+ , numnode
26+ , plainToTSquery
27+ , phraseToTSquery
28+ , websearchToTSquery
29+ , queryTree
30+ , toTSquery
31+ , toTSvector
32+ , setWeight
33+ , strip
34+ , jsonToTSvector
35+ , jsonbToTSvector
36+ , tsDelete
37+ , tsFilter
38+ , tsHeadline
39+ ) where
40+
41+import Squeal.PostgreSQL.Expression
42+import Squeal.PostgreSQL.List
43+import Squeal.PostgreSQL.Schema
44+
45+-- | `Squeal.PostgreSQL.Expression.Type.tsvector` matches tsquery ?
46+(@@) :: Operator (null 'PGtsvector) (null 'PGtsquery) ('Null 'PGbool)
47+(@@) = unsafeBinaryOp "@@"
48+
49+-- | AND `Squeal.PostgreSQL.Expression.Type.tsquery`s together
50+(.&) :: Operator (null 'PGtsquery) (null 'PGtsquery) (null 'PGtsquery)
51+(.&) = unsafeBinaryOp "&&"
52+
53+-- | OR `Squeal.PostgreSQL.Expression.Type.tsquery`s together
54+(.|) :: Operator (null 'PGtsquery) (null 'PGtsquery) (null 'PGtsquery)
55+(.|) = unsafeBinaryOp "||"
56+
57+-- | negate a `Squeal.PostgreSQL.Expression.Type.tsquery`
58+(.!) :: null 'PGtsquery --> null 'PGtsquery
59+(.!) = unsafeLeftOp "!!"
60+
61+-- | `Squeal.PostgreSQL.Expression.Type.tsquery` followed by
62+-- `Squeal.PostgreSQL.Expression.Type.tsquery`
63+(<->) :: Operator (null 'PGtsquery) (null 'PGtsquery) (null 'PGtsquery)
64+(<->) = unsafeBinaryOp "<->"
65+
66+-- | convert array of lexemes to `Squeal.PostgreSQL.Expression.Type.tsvector`
67+arrayToTSvector
68+ :: null ('PGvararray ('NotNull 'PGtext))
69+ --> null 'PGtsvector
70+arrayToTSvector = unsafeFunction "array_to_tsvector"
71+
72+-- | number of lexemes in `Squeal.PostgreSQL.Expression.Type.tsvector`
73+tsvectorLength :: null 'PGtsvector --> null 'PGint4
74+tsvectorLength = unsafeFunction "length"
75+
76+-- | number of lexemes plus operators in `Squeal.PostgreSQL.Expression.Type.tsquery`
77+numnode :: null 'PGtsquery --> null 'PGint4
78+numnode = unsafeFunction "numnode"
79+
80+-- | produce `Squeal.PostgreSQL.Expression.Type.tsquery` ignoring punctuation
81+plainToTSquery :: null 'PGtext --> null 'PGtsquery
82+plainToTSquery = unsafeFunction "plainto_tsquery"
83+
84+-- | produce `Squeal.PostgreSQL.Expression.Type.tsquery` that searches for a phrase,
85+-- ignoring punctuation
86+phraseToTSquery :: null 'PGtext --> null 'PGtsquery
87+phraseToTSquery = unsafeFunction "phraseto_tsquery"
88+
89+-- | produce `Squeal.PostgreSQL.Expression.Type.tsquery` from a web search style query
90+websearchToTSquery :: null 'PGtext --> null 'PGtsquery
91+websearchToTSquery = unsafeFunction "websearch_to_tsquery"
92+
93+-- | get indexable part of a `Squeal.PostgreSQL.Expression.Type.tsquery`
94+queryTree :: null 'PGtsquery --> null 'PGtext
95+queryTree = unsafeFunction "query_tree"
96+
97+-- | normalize words and convert to `Squeal.PostgreSQL.Expression.Type.tsquery`
98+toTSquery :: null 'PGtext --> null 'PGtsquery
99+toTSquery = unsafeFunction "to_tsquery"
100+
101+-- | reduce document text to `Squeal.PostgreSQL.Expression.Type.tsvector`
102+toTSvector
103+ :: ty `In` '[ 'PGtext, 'PGjson, 'PGjsonb]
104+ => null ty --> null 'PGtsvector
105+toTSvector = unsafeFunction "to_tsvector"
106+
107+-- | assign weight to each element of `Squeal.PostgreSQL.Expression.Type.tsvector`
108+setWeight :: '[null 'PGtsvector, null ('PGchar 1)] ---> null 'PGtsvector
109+setWeight = unsafeFunctionN "set_weight"
110+
111+-- | remove positions and weights from `Squeal.PostgreSQL.Expression.Type.tsvector`
112+strip :: null 'PGtsvector --> null 'PGtsvector
113+strip = unsafeFunction "strip"
114+
115+-- | @jsonToTSvector (document *: filter)@
116+-- reduce each value in the document, specified by filter to a `Squeal.PostgreSQL.Expression.Type.tsvector`,
117+-- and then concatenate those in document order to produce a single `Squeal.PostgreSQL.Expression.Type.tsvector`.
118+-- filter is a `Squeal.PostgreSQL.Expression.Type.json` array, that enumerates what kind of elements
119+-- need to be included into the resulting `Squeal.PostgreSQL.Expression.Type.tsvector`.
120+-- Possible values for filter are "string" (to include all string values),
121+-- "numeric" (to include all numeric values in the string format),
122+-- "boolean" (to include all Boolean values in the string format "true"/"false"),
123+-- "key" (to include all keys) or "all" (to include all above).
124+-- These values can be combined together to include, e.g. all string and numeric values.
125+jsonToTSvector :: '[null 'PGjson, null 'PGjson] ---> null 'PGtsvector
126+jsonToTSvector = unsafeFunctionN "json_to_tsvector"
127+
128+-- | @jsonbToTSvector (document *: filter)@
129+-- reduce each value in the document, specified by filter to a `Squeal.PostgreSQL.Expression.Type.tsvector`,
130+-- and then concatenate those in document order to produce a single `Squeal.PostgreSQL.Expression.Type.tsvector`.
131+-- filter is a `Squeal.PostgreSQL.Expression.Type.jsonb` array, that enumerates what kind of elements
132+-- need to be included into the resulting `Squeal.PostgreSQL.Expression.Type.tsvector`.
133+-- Possible values for filter are "string" (to include all string values),
134+-- "numeric" (to include all numeric values in the string format),
135+-- "boolean" (to include all Boolean values in the string format "true"/"false"),
136+-- "key" (to include all keys) or "all" (to include all above).
137+-- These values can be combined together to include, e.g. all string and numeric values.
138+jsonbToTSvector :: '[null 'PGjsonb, null 'PGjsonb] ---> null 'PGtsvector
139+jsonbToTSvector = unsafeFunctionN "jsonb_to_tsvector"
140+
141+-- | remove given lexeme from `Squeal.PostgreSQL.Expression.Type.tsvector`
142+tsDelete ::
143+ '[null 'PGtsvector, null ('PGvararray ('NotNull 'PGtext))]
144+ ---> null 'PGtsvector
145+tsDelete = unsafeFunctionN "ts_delete"
146+
147+-- | select only elements with given weights from `Squeal.PostgreSQL.Expression.Type.tsvector`
148+tsFilter ::
149+ '[null 'PGtsvector, null ('PGvararray ('NotNull ('PGchar 1)))]
150+ ---> null 'PGtsvector
151+tsFilter = unsafeFunctionN "ts_filter"
152+
153+-- | display a `Squeal.PostgreSQL.Expression.Type.tsquery` match
154+tsHeadline
155+ :: document `In` '[ 'PGtext, 'PGjson, 'PGjsonb]
156+ => '[null document, null 'PGtsquery] ---> null 'PGtext
157+tsHeadline = unsafeFunctionN "ts_headline"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Time.hsnew file+192
@@ -0,0 +1,192 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Time
3+Description: Date/Time expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Date/Time functions and operators
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , DeriveGeneric
14+ , FunctionalDependencies
15+ , LambdaCase
16+ , MultiParamTypeClasses
17+ , OverloadedStrings
18+ , PolyKinds
19+ , RankNTypes
20+ , TypeOperators
21+#-}
22+
23+module Squeal.PostgreSQL.Expression.Time
24+ ( TimeOp (..)
25+ , currentDate
26+ , currentTime
27+ , currentTimestamp
28+ , localTime
29+ , localTimestamp
30+ , now
31+ , makeDate
32+ , makeTime
33+ , makeTimestamp
34+ , makeTimestamptz
35+ , interval_
36+ , TimeUnit (..)
37+ ) where
38+
39+import Data.String
40+
41+import qualified GHC.Generics as GHC
42+import qualified Generics.SOP as SOP
43+
44+import Squeal.PostgreSQL.Expression
45+import Squeal.PostgreSQL.Render
46+import Squeal.PostgreSQL.Schema
47+
48+-- $setup
49+-- >>> import Squeal.PostgreSQL
50+
51+-- | >>> printSQL currentDate
52+-- CURRENT_DATE
53+currentDate :: Expr (null 'PGdate)
54+currentDate = UnsafeExpression "CURRENT_DATE"
55+
56+-- | >>> printSQL currentTime
57+-- CURRENT_TIME
58+currentTime :: Expr (null 'PGtimetz)
59+currentTime = UnsafeExpression "CURRENT_TIME"
60+
61+-- | >>> printSQL currentTimestamp
62+-- CURRENT_TIMESTAMP
63+currentTimestamp :: Expr (null 'PGtimestamptz)
64+currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"
65+
66+-- | >>> printSQL localTime
67+-- LOCALTIME
68+localTime :: Expr (null 'PGtime)
69+localTime = UnsafeExpression "LOCALTIME"
70+
71+-- | >>> printSQL localTimestamp
72+-- LOCALTIMESTAMP
73+localTimestamp :: Expr (null 'PGtimestamp)
74+localTimestamp = UnsafeExpression "LOCALTIMESTAMP"
75+
76+-- | Current date and time (equivalent to `currentTimestamp`)
77+--
78+-- >>> printSQL now
79+-- now()
80+now :: Expr (null 'PGtimestamptz)
81+now = UnsafeExpression "now()"
82+
83+{-|
84+Create date from year, month and day fields
85+
86+>>> printSQL (makeDate (1984 :* 7 *: 3))
87+make_date(1984, 7, 3)
88+-}
89+makeDate :: '[ null 'PGint4, null 'PGint4, null 'PGint4 ] ---> null 'PGdate
90+makeDate = unsafeFunctionN "make_date"
91+
92+{-|
93+Create time from hour, minute and seconds fields
94+
95+>>> printSQL (makeTime (8 :* 15 *: 23.5))
96+make_time(8, 15, 23.5)
97+-}
98+makeTime :: '[ null 'PGint4, null 'PGint4, null 'PGfloat8 ] ---> null 'PGtime
99+makeTime = unsafeFunctionN "make_time"
100+
101+{-|
102+Create timestamp from year, month, day, hour, minute and seconds fields
103+
104+>>> printSQL (makeTimestamp (2013 :* 7 :* 15 :* 8 :* 15 *: 23.5))
105+make_timestamp(2013, 7, 15, 8, 15, 23.5)
106+-}
107+makeTimestamp ::
108+ '[ null 'PGint4, null 'PGint4, null 'PGint4
109+ , null 'PGint4, null 'PGint4, null 'PGfloat8 ] ---> null 'PGtimestamp
110+makeTimestamp = unsafeFunctionN "make_timestamp"
111+
112+{-|
113+Create timestamp with time zone from
114+year, month, day, hour, minute and seconds fields;
115+the current time zone is used
116+
117+>>> printSQL (makeTimestamptz (2013 :* 7 :* 15 :* 8 :* 15 *: 23.5))
118+make_timestamptz(2013, 7, 15, 8, 15, 23.5)
119+-}
120+makeTimestamptz ::
121+ '[ null 'PGint4, null 'PGint4, null 'PGint4
122+ , null 'PGint4, null 'PGint4, null 'PGfloat8 ] ---> null 'PGtimestamptz
123+makeTimestamptz = unsafeFunctionN "make_timestamptz"
124+
125+{-|
126+Affine space operations on time types.
127+-}
128+class TimeOp time diff | time -> diff where
129+ {-|
130+ >>> printSQL (makeDate (1984 :* 7 *: 3) !+ 365)
131+ (make_date(1984, 7, 3) + 365)
132+ -}
133+ (!+) :: Operator (null time) (null diff) (null time)
134+ (!+) = unsafeBinaryOp "+"
135+ {-|
136+ >>> printSQL (365 +! makeDate (1984 :* 7 *: 3))
137+ (365 + make_date(1984, 7, 3))
138+ -}
139+ (+!) :: Operator (null diff) (null time) (null time)
140+ (+!) = unsafeBinaryOp "+"
141+ {-|
142+ >>> printSQL (makeDate (1984 :* 7 *: 3) !- 365)
143+ (make_date(1984, 7, 3) - 365)
144+ -}
145+ (!-) :: Operator (null time) (null diff) (null time)
146+ (!-) = unsafeBinaryOp "-"
147+ {-|
148+ >>> printSQL (makeDate (1984 :* 7 *: 3) !-! currentDate)
149+ (make_date(1984, 7, 3) - CURRENT_DATE)
150+ -}
151+ (!-!) :: Operator (null time) (null time) (null diff)
152+ (!-!) = unsafeBinaryOp "-"
153+instance TimeOp 'PGtimestamp 'PGinterval
154+instance TimeOp 'PGtimestamptz 'PGinterval
155+instance TimeOp 'PGtime 'PGinterval
156+instance TimeOp 'PGtimetz 'PGinterval
157+instance TimeOp 'PGinterval 'PGinterval
158+instance TimeOp 'PGdate 'PGint4
159+infixl 6 !+
160+infixl 6 +!
161+infixl 6 !-
162+infixl 6 !-!
163+
164+-- | A `TimeUnit` to use in `interval_` construction.
165+data TimeUnit
166+ = Years | Months | Weeks | Days
167+ | Hours | Minutes | Seconds
168+ | Microseconds | Milliseconds
169+ | Decades | Centuries | Millennia
170+ deriving (Eq, Ord, Show, Read, Enum, GHC.Generic)
171+instance SOP.Generic TimeUnit
172+instance SOP.HasDatatypeInfo TimeUnit
173+instance RenderSQL TimeUnit where
174+ renderSQL = \case
175+ Years -> "years"
176+ Months -> "months"
177+ Weeks -> "weeks"
178+ Days -> "days"
179+ Hours -> "hours"
180+ Minutes -> "minutes"
181+ Seconds -> "seconds"
182+ Microseconds -> "microseconds"
183+ Milliseconds -> "milliseconds"
184+ Decades -> "decades"
185+ Centuries -> "centuries"
186+ Millennia -> "millennia"
187+
188+-- | >>> printSQL $ interval_ 7 Days
189+-- (INTERVAL '7.0 days')
190+interval_ :: Double -> TimeUnit -> Expr (null 'PGinterval)
191+interval_ num unit = UnsafeExpression . parenthesized $ "INTERVAL" <+>
192+ "'" <> fromString (show num) <+> renderSQL unit <> "'"
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Type.hsnew file+446
@@ -0,0 +1,446 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression
3+Description: Type expressions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Type expressions.
9+-}
10+
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , DataKinds
14+ , DeriveGeneric
15+ , FlexibleContexts
16+ , FlexibleInstances
17+ , GADTs
18+ , GeneralizedNewtypeDeriving
19+ , KindSignatures
20+ , MultiParamTypeClasses
21+ , OverloadedStrings
22+ , RankNTypes
23+ , ScopedTypeVariables
24+ , TypeApplications
25+ , TypeOperators
26+ , UndecidableInstances
27+#-}
28+
29+module Squeal.PostgreSQL.Expression.Type
30+ ( -- * type casting
31+ cast
32+ , astype
33+ , inferredtype
34+ -- * type expressions
35+ , TypeExpression (..)
36+ , typedef
37+ , typetable
38+ , typeview
39+ , bool
40+ , int2
41+ , smallint
42+ , int4
43+ , int
44+ , integer
45+ , int8
46+ , bigint
47+ , numeric
48+ , float4
49+ , real
50+ , float8
51+ , doublePrecision
52+ , money
53+ , text
54+ , char
55+ , character
56+ , varchar
57+ , characterVarying
58+ , bytea
59+ , timestamp
60+ , timestampWithTimeZone
61+ , timestamptz
62+ , date
63+ , time
64+ , timeWithTimeZone
65+ , timetz
66+ , interval
67+ , uuid
68+ , inet
69+ , json
70+ , jsonb
71+ , vararray
72+ , fixarray
73+ , tsvector
74+ , tsquery
75+ , oid
76+ , int4range
77+ , int8range
78+ , numrange
79+ , tsrange
80+ , tstzrange
81+ , daterange
82+ -- * column type definitions
83+ , ColumnTypeExpression (..)
84+ , nullable
85+ , notNullable
86+ , default_
87+ , serial2
88+ , smallserial
89+ , serial4
90+ , serial
91+ , serial8
92+ , bigserial
93+ , hask
94+ -- * type inference
95+ , PGTyped (..)
96+ , PGNullityTyped (..)
97+ , FieldTyped (..)
98+ ) where
99+
100+import Control.DeepSeq
101+import Data.ByteString
102+import Data.String
103+import GHC.TypeLits
104+
105+import qualified Data.ByteString as ByteString
106+import qualified GHC.Generics as GHC
107+import qualified Generics.SOP as SOP
108+
109+import Squeal.PostgreSQL.Alias
110+import Squeal.PostgreSQL.Expression
111+import Squeal.PostgreSQL.PG
112+import Squeal.PostgreSQL.Render
113+import Squeal.PostgreSQL.Schema
114+
115+-- $setup
116+-- >>> import Squeal.PostgreSQL
117+
118+-- When a `cast` is applied to an `Expression` of a known type, it
119+-- represents a run-time type conversion. The cast will succeed only if a
120+-- suitable type conversion operation has been defined.
121+--
122+-- | >>> printSQL $ true & cast int4
123+-- (TRUE :: int4)
124+cast
125+ :: TypeExpression schemas ty1
126+ -- ^ type to cast as
127+ -> Expression outer commons grp schemas params from ty0
128+ -- ^ value to convert
129+ -> Expression outer commons grp schemas params from ty1
130+cast ty x = UnsafeExpression $ parenthesized $
131+ renderSQL x <+> "::" <+> renderSQL ty
132+
133+-- | A safe version of `cast` which just matches a value with its type.
134+--
135+-- >>> printSQL (1 & astype int)
136+-- (1 :: int)
137+astype
138+ :: TypeExpression schemas ty
139+ -- ^ type to specify as
140+ -> Expression outer commons grp schemas params from ty
141+ -- ^ value
142+ -> Expression outer commons grp schemas params from ty
143+astype = cast
144+
145+-- | `inferredtype` will add a type annotation to an `Expression`
146+-- which can be useful for fixing the storage type of a value.
147+--
148+-- >>> printSQL (inferredtype true)
149+-- (TRUE :: bool)
150+inferredtype
151+ :: PGTyped schemas ty
152+ => Expression outer common grp schemas params from ty
153+ -- ^ value
154+ -> Expression outer common grp schemas params from ty
155+inferredtype = astype pgtype
156+
157+{-----------------------------------------
158+type expressions
159+-----------------------------------------}
160+
161+-- | `TypeExpression`s are used in `cast`s and
162+-- `Squeal.PostgreSQL.Definition.createTable` commands.
163+newtype TypeExpression (schemas :: SchemasType) (ty :: NullityType)
164+ = UnsafeTypeExpression { renderTypeExpression :: ByteString }
165+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
166+instance RenderSQL (TypeExpression schemas ty) where
167+ renderSQL = renderTypeExpression
168+
169+-- | The enum or composite type in a `Typedef` can be expressed by its alias.
170+typedef
171+ :: (Has sch schemas schema, Has td schema ('Typedef ty))
172+ => QualifiedAlias sch td
173+ -- ^ type alias
174+ -> TypeExpression schemas (null ty)
175+typedef = UnsafeTypeExpression . renderSQL
176+
177+-- | The composite type corresponding to a `Table` definition can be expressed
178+-- by its alias.
179+typetable
180+ :: (Has sch schemas schema, Has tab schema ('Table table))
181+ => QualifiedAlias sch tab
182+ -- ^ table alias
183+ -> TypeExpression schemas (null ('PGcomposite (TableToRow table)))
184+typetable = UnsafeTypeExpression . renderSQL
185+
186+-- | The composite type corresponding to a `View` definition can be expressed
187+-- by its alias.
188+typeview
189+ :: (Has sch schemas schema, Has vw schema ('View view))
190+ => QualifiedAlias sch vw
191+ -- ^ view alias
192+ -> TypeExpression schemas (null ('PGcomposite view))
193+typeview = UnsafeTypeExpression . renderSQL
194+
195+-- | logical Boolean (true/false)
196+bool :: TypeExpression schemas (null 'PGbool)
197+bool = UnsafeTypeExpression "bool"
198+-- | signed two-byte integer
199+int2, smallint :: TypeExpression schemas (null 'PGint2)
200+int2 = UnsafeTypeExpression "int2"
201+smallint = UnsafeTypeExpression "smallint"
202+-- | signed four-byte integer
203+int4, int, integer :: TypeExpression schemas (null 'PGint4)
204+int4 = UnsafeTypeExpression "int4"
205+int = UnsafeTypeExpression "int"
206+integer = UnsafeTypeExpression "integer"
207+-- | signed eight-byte integer
208+int8, bigint :: TypeExpression schemas (null 'PGint8)
209+int8 = UnsafeTypeExpression "int8"
210+bigint = UnsafeTypeExpression "bigint"
211+-- | arbitrary precision numeric type
212+numeric :: TypeExpression schemas (null 'PGnumeric)
213+numeric = UnsafeTypeExpression "numeric"
214+-- | single precision floating-point number (4 bytes)
215+float4, real :: TypeExpression schemas (null 'PGfloat4)
216+float4 = UnsafeTypeExpression "float4"
217+real = UnsafeTypeExpression "real"
218+-- | double precision floating-point number (8 bytes)
219+float8, doublePrecision :: TypeExpression schemas (null 'PGfloat8)
220+float8 = UnsafeTypeExpression "float8"
221+doublePrecision = UnsafeTypeExpression "double precision"
222+-- | currency amount
223+money :: TypeExpression schema (null 'PGmoney)
224+money = UnsafeTypeExpression "money"
225+-- | variable-length character string
226+text :: TypeExpression schemas (null 'PGtext)
227+text = UnsafeTypeExpression "text"
228+-- | fixed-length character string
229+char, character
230+ :: forall n schemas null. (KnownNat n, 1 <= n)
231+ => TypeExpression schemas (null ('PGchar n))
232+char = UnsafeTypeExpression $ "char(" <> renderNat @n <> ")"
233+character = UnsafeTypeExpression $ "character(" <> renderNat @n <> ")"
234+-- | variable-length character string
235+varchar, characterVarying
236+ :: forall n schemas null. (KnownNat n, 1 <= n)
237+ => TypeExpression schemas (null ('PGvarchar n))
238+varchar = UnsafeTypeExpression $ "varchar(" <> renderNat @n <> ")"
239+characterVarying = UnsafeTypeExpression $
240+ "character varying(" <> renderNat @n <> ")"
241+-- | binary data ("byte array")
242+bytea :: TypeExpression schemas (null 'PGbytea)
243+bytea = UnsafeTypeExpression "bytea"
244+-- | date and time (no time zone)
245+timestamp :: TypeExpression schemas (null 'PGtimestamp)
246+timestamp = UnsafeTypeExpression "timestamp"
247+-- | date and time, including time zone
248+timestampWithTimeZone, timestamptz :: TypeExpression schemas (null 'PGtimestamptz)
249+timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"
250+timestamptz = UnsafeTypeExpression "timestamptz"
251+-- | calendar date (year, month, day)
252+date :: TypeExpression schemas (null 'PGdate)
253+date = UnsafeTypeExpression "date"
254+-- | time of day (no time zone)
255+time :: TypeExpression schemas (null 'PGtime)
256+time = UnsafeTypeExpression "time"
257+-- | time of day, including time zone
258+timeWithTimeZone, timetz :: TypeExpression schemas (null 'PGtimetz)
259+timeWithTimeZone = UnsafeTypeExpression "time with time zone"
260+timetz = UnsafeTypeExpression "timetz"
261+-- | time span
262+interval :: TypeExpression schemas (null 'PGinterval)
263+interval = UnsafeTypeExpression "interval"
264+-- | universally unique identifier
265+uuid :: TypeExpression schemas (null 'PGuuid)
266+uuid = UnsafeTypeExpression "uuid"
267+-- | IPv4 or IPv6 host address
268+inet :: TypeExpression schemas (null 'PGinet)
269+inet = UnsafeTypeExpression "inet"
270+-- | textual JSON data
271+json :: TypeExpression schemas (null 'PGjson)
272+json = UnsafeTypeExpression "json"
273+-- | binary JSON data, decomposed
274+jsonb :: TypeExpression schemas (null 'PGjsonb)
275+jsonb = UnsafeTypeExpression "jsonb"
276+-- | variable length array
277+vararray
278+ :: TypeExpression schemas pg
279+ -> TypeExpression schemas (null ('PGvararray pg))
280+vararray ty = UnsafeTypeExpression $ renderSQL ty <> "[]"
281+-- | fixed length array
282+--
283+-- >>> renderSQL (fixarray @'[2] json)
284+-- "json[2]"
285+fixarray
286+ :: forall dims schemas null pg. SOP.All KnownNat dims
287+ => TypeExpression schemas pg
288+ -> TypeExpression schemas (null ('PGfixarray dims pg))
289+fixarray ty = UnsafeTypeExpression $
290+ renderSQL ty <> renderDims @dims
291+ where
292+ renderDims :: forall ns. SOP.All KnownNat ns => ByteString
293+ renderDims =
294+ ("[" <>)
295+ . (<> "]")
296+ . ByteString.intercalate "]["
297+ . SOP.hcollapse
298+ $ SOP.hcmap (SOP.Proxy @KnownNat)
299+ (K . fromString . show . natVal)
300+ (SOP.hpure SOP.Proxy :: SOP.NP SOP.Proxy ns)
301+-- | text search query
302+tsvector :: TypeExpression schemas (null 'PGtsvector)
303+tsvector = UnsafeTypeExpression "tsvector"
304+-- | text search document
305+tsquery :: TypeExpression schemas (null 'PGtsquery)
306+tsquery = UnsafeTypeExpression "tsquery"
307+-- | Object identifiers (OIDs) are used internally by PostgreSQL
308+-- as primary keys for various system tables.
309+oid :: TypeExpression schemas (null 'PGoid)
310+oid = UnsafeTypeExpression "oid"
311+-- | Range of integer
312+int4range :: TypeExpression schemas (null ('PGrange 'PGint4))
313+int4range = UnsafeTypeExpression "int4range"
314+-- | Range of bigint
315+int8range :: TypeExpression schemas (null ('PGrange 'PGint8))
316+int8range = UnsafeTypeExpression "int8range"
317+-- | Range of numeric
318+numrange :: TypeExpression schemas (null ('PGrange 'PGnumeric))
319+numrange = UnsafeTypeExpression "numrange"
320+-- | Range of timestamp without time zone
321+tsrange :: TypeExpression schemas (null ('PGrange 'PGtimestamp))
322+tsrange = UnsafeTypeExpression "tsrange"
323+-- | Range of timestamp with time zone
324+tstzrange :: TypeExpression schemas (null ('PGrange 'PGtimestamptz))
325+tstzrange = UnsafeTypeExpression "tstzrange"
326+-- | Range of date
327+daterange :: TypeExpression schemas (null ('PGrange 'PGdate))
328+daterange = UnsafeTypeExpression "daterange"
329+
330+-- | `pgtype` is a demoted version of a `PGType`
331+class PGTyped schemas (ty :: NullityType) where
332+ pgtype :: TypeExpression schemas ty
333+instance PGTyped schemas (null 'PGbool) where pgtype = bool
334+instance PGTyped schemas (null 'PGint2) where pgtype = int2
335+instance PGTyped schemas (null 'PGint4) where pgtype = int4
336+instance PGTyped schemas (null 'PGint8) where pgtype = int8
337+instance PGTyped schemas (null 'PGnumeric) where pgtype = numeric
338+instance PGTyped schemas (null 'PGfloat4) where pgtype = float4
339+instance PGTyped schemas (null 'PGfloat8) where pgtype = float8
340+instance PGTyped schemas (null 'PGmoney) where pgtype = money
341+instance PGTyped schemas (null 'PGtext) where pgtype = text
342+instance (KnownNat n, 1 <= n)
343+ => PGTyped schemas (null ('PGchar n)) where pgtype = char @n
344+instance (KnownNat n, 1 <= n)
345+ => PGTyped schemas (null ('PGvarchar n)) where pgtype = varchar @n
346+instance PGTyped schemas (null 'PGbytea) where pgtype = bytea
347+instance PGTyped schemas (null 'PGtimestamp) where pgtype = timestamp
348+instance PGTyped schemas (null 'PGtimestamptz) where pgtype = timestampWithTimeZone
349+instance PGTyped schemas (null 'PGdate) where pgtype = date
350+instance PGTyped schemas (null 'PGtime) where pgtype = time
351+instance PGTyped schemas (null 'PGtimetz) where pgtype = timeWithTimeZone
352+instance PGTyped schemas (null 'PGinterval) where pgtype = interval
353+instance PGTyped schemas (null 'PGuuid) where pgtype = uuid
354+instance PGTyped schemas (null 'PGjson) where pgtype = json
355+instance PGTyped schemas (null 'PGjsonb) where pgtype = jsonb
356+instance PGTyped schemas ty
357+ => PGTyped schemas (null ('PGvararray ty)) where
358+ pgtype = vararray (pgtype @schemas @ty)
359+instance (SOP.All KnownNat dims, PGTyped schemas ty)
360+ => PGTyped schemas (null ('PGfixarray dims ty)) where
361+ pgtype = fixarray @dims (pgtype @schemas @ty)
362+instance PGTyped schemas (null 'PGtsvector) where pgtype = tsvector
363+instance PGTyped schemas (null 'PGtsquery) where pgtype = tsquery
364+instance PGTyped schemas (null 'PGoid) where pgtype = oid
365+instance PGTyped schemas (null ('PGrange 'PGint4)) where pgtype = int4range
366+instance PGTyped schemas (null ('PGrange 'PGint8)) where pgtype = int8range
367+instance PGTyped schemas (null ('PGrange 'PGnumeric)) where pgtype = numrange
368+instance PGTyped schemas (null ('PGrange 'PGtimestamp)) where pgtype = tsrange
369+instance PGTyped schemas (null ('PGrange 'PGtimestamptz)) where pgtype = tstzrange
370+instance PGTyped schemas (null ('PGrange 'PGdate)) where pgtype = daterange
371+
372+-- | Lift `PGTyped` to a field
373+class FieldTyped schemas ty where
374+ fieldtype :: Aliased (TypeExpression schemas) ty
375+instance (KnownSymbol alias, PGTyped schemas ty)
376+ => FieldTyped schemas (alias ::: ty) where
377+ fieldtype = pgtype `As` Alias
378+
379+-- | `ColumnTypeExpression`s are used in `createTable` commands.
380+newtype ColumnTypeExpression (schemas :: SchemasType) (ty :: ColumnType)
381+ = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }
382+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
383+instance RenderSQL (ColumnTypeExpression schemas ty) where
384+ renderSQL = renderColumnTypeExpression
385+
386+-- | used in `createTable` commands as a column constraint to note that
387+-- @NULL@ may be present in a column
388+nullable
389+ :: TypeExpression schemas (nullity ty)
390+ -> ColumnTypeExpression schemas ('NoDef :=> 'Null ty)
391+nullable ty = UnsafeColumnTypeExpression $ renderSQL ty <+> "NULL"
392+
393+-- | used in `createTable` commands as a column constraint to ensure
394+-- @NULL@ is not present in a column
395+notNullable
396+ :: TypeExpression schemas (nullity ty)
397+ -> ColumnTypeExpression schemas ('NoDef :=> 'NotNull ty)
398+notNullable ty = UnsafeColumnTypeExpression $ renderSQL ty <+> "NOT NULL"
399+
400+-- | used in `createTable` commands as a column constraint to give a default
401+default_
402+ :: Expression '[] '[] 'Ungrouped schemas '[] '[] ty
403+ -> ColumnTypeExpression schemas ('NoDef :=> ty)
404+ -> ColumnTypeExpression schemas ('Def :=> ty)
405+default_ x ty = UnsafeColumnTypeExpression $
406+ renderSQL ty <+> "DEFAULT" <+> renderExpression x
407+
408+-- | not a true type, but merely a notational convenience for creating
409+-- unique identifier columns with type `PGint2`
410+serial2, smallserial
411+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint2)
412+serial2 = UnsafeColumnTypeExpression "serial2"
413+smallserial = UnsafeColumnTypeExpression "smallserial"
414+-- | not a true type, but merely a notational convenience for creating
415+-- unique identifier columns with type `PGint4`
416+serial4, serial
417+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint4)
418+serial4 = UnsafeColumnTypeExpression "serial4"
419+serial = UnsafeColumnTypeExpression "serial"
420+-- | not a true type, but merely a notational convenience for creating
421+-- unique identifier columns with type `PGint8`
422+serial8, bigserial
423+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint8)
424+serial8 = UnsafeColumnTypeExpression "serial8"
425+bigserial = UnsafeColumnTypeExpression "bigserial"
426+
427+-- | Like @PGTyped@ but also accounts for nullity.
428+class PGNullityTyped schemas (nullty :: NullityType) where
429+ pgNullityType :: ColumnTypeExpression schemas ('NoDef :=> nullty)
430+
431+instance PGTyped schemas ('Null ty) => PGNullityTyped schemas ('Null ty) where
432+ pgNullityType = nullable (pgtype @_ @('Null ty))
433+
434+instance PGTyped schemas ('NotNull ty) => PGNullityTyped schemas ('NotNull ty) where
435+ pgNullityType = notNullable (pgtype @_ @('NotNull ty))
436+
437+-- | Allow you to specify pg column types in relation to haskell types.
438+-- >>> printSQL $ hask @(Maybe String)
439+-- text NULL
440+--
441+-- >>> printSQL $ hask @Double
442+-- float8 NOT NULL
443+hask
444+ :: forall hask schemas. PGNullityTyped schemas (NullPG hask)
445+ => ColumnTypeExpression schemas ('NoDef :=> NullPG hask)
446+hask = pgNullityType
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Window.hsnew file+284
@@ -0,0 +1,284 @@
1+{-|
2+Module: Squeal.PostgreSQL.Expression.Window
3+Description: Window functions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Window functions and definitions
9+-}
10+
11+{-# LANGUAGE
12+ DataKinds
13+ , DeriveGeneric
14+ , FlexibleContexts
15+ , FlexibleInstances
16+ , GADTs
17+ , GeneralizedNewtypeDeriving
18+ , LambdaCase
19+ , MultiParamTypeClasses
20+ , OverloadedStrings
21+ , RankNTypes
22+ , KindSignatures
23+#-}
24+
25+module Squeal.PostgreSQL.Expression.Window
26+ ( -- * functions
27+ partitionBy
28+ , rank
29+ , rowNumber
30+ , denseRank
31+ , percentRank
32+ , cumeDist
33+ , ntile
34+ , lag
35+ , lead
36+ , firstValue
37+ , lastValue
38+ , nthValue
39+ , unsafeWindowFunction1
40+ , unsafeWindowFunctionN
41+ -- * types
42+ , WindowFunction (..)
43+ , WindowDefinition (..)
44+ , WinFun0
45+ , WinFun1
46+ , WinFunN
47+ ) where
48+
49+import Control.DeepSeq
50+import Data.ByteString
51+
52+import qualified GHC.Generics as GHC
53+import qualified Generics.SOP as SOP
54+
55+import Squeal.PostgreSQL.Alias
56+import Squeal.PostgreSQL.Expression
57+import Squeal.PostgreSQL.Expression.Aggregate
58+import Squeal.PostgreSQL.Expression.Sort
59+import Squeal.PostgreSQL.List
60+import Squeal.PostgreSQL.Render
61+import Squeal.PostgreSQL.Schema
62+
63+instance Aggregate
64+ (Expression outer commons grp schemas params from)
65+ (NP (Expression outer commons grp schemas params from))
66+ (WindowFunction outer commons grp schemas params from) where
67+ countStar = UnsafeWindowFunction "count(*)"
68+ count = unsafeWindowFunction1 "count"
69+ sum_ = unsafeWindowFunction1 "sum"
70+ arrayAgg = unsafeWindowFunction1 "array_agg"
71+ jsonAgg = unsafeWindowFunction1 "json_agg"
72+ jsonbAgg = unsafeWindowFunction1 "jsonb_agg"
73+ bitAnd = unsafeWindowFunction1 "bit_and"
74+ bitOr = unsafeWindowFunction1 "bit_or"
75+ boolAnd = unsafeWindowFunction1 "bool_and"
76+ boolOr = unsafeWindowFunction1 "bool_or"
77+ every = unsafeWindowFunction1 "every"
78+ max_ = unsafeWindowFunction1 "max"
79+ min_ = unsafeWindowFunction1 "min"
80+ avg = unsafeWindowFunction1 "avg"
81+ corr = unsafeWindowFunctionN "corr"
82+ covarPop = unsafeWindowFunctionN "covar_pop"
83+ covarSamp = unsafeWindowFunctionN "covar_samp"
84+ regrAvgX = unsafeWindowFunctionN "regr_avgx"
85+ regrAvgY = unsafeWindowFunctionN "regr_avgy"
86+ regrCount = unsafeWindowFunctionN "regr_count"
87+ regrIntercept = unsafeWindowFunctionN "regr_intercept"
88+ regrR2 = unsafeWindowFunctionN "regr_r2"
89+ regrSlope = unsafeWindowFunctionN "regr_slope"
90+ regrSxx = unsafeWindowFunctionN "regr_sxx"
91+ regrSxy = unsafeWindowFunctionN "regr_sxy"
92+ regrSyy = unsafeWindowFunctionN "regr_syy"
93+ stddev = unsafeWindowFunction1 "stddev"
94+ stddevPop = unsafeWindowFunction1 "stddev_pop"
95+ stddevSamp = unsafeWindowFunction1 "stddev_samp"
96+ variance = unsafeWindowFunction1 "variance"
97+ varPop = unsafeWindowFunction1 "var_pop"
98+ varSamp = unsafeWindowFunction1 "var_samp"
99+
100+-- | A `WindowDefinition` is a set of table rows that are somehow related
101+-- to the current row
102+data WindowDefinition outer commons grp schemas params from where
103+ WindowDefinition
104+ :: SOP.SListI bys
105+ => NP (Expression outer commons grp schemas params from) bys
106+ -- ^ `partitionBy` clause
107+ -> [SortExpression outer commons grp schemas params from]
108+ -- ^ `Squeal.PostgreSQL.Expression.Sort.orderBy` clause
109+ -> WindowDefinition outer commons grp schemas params from
110+
111+instance OrderBy WindowDefinition where
112+ orderBy sortsR (WindowDefinition parts sortsL)
113+ = WindowDefinition parts (sortsL ++ sortsR)
114+
115+instance RenderSQL (WindowDefinition outer commons schemas from grp params) where
116+ renderSQL (WindowDefinition part ord) =
117+ renderPartitionByClause part <> renderOrderByClause ord
118+ where
119+ renderPartitionByClause = \case
120+ Nil -> ""
121+ parts -> "PARTITION" <+> "BY" <+> renderCommaSeparated renderExpression parts
122+ renderOrderByClause = \case
123+ [] -> ""
124+ srts -> " ORDER" <+> "BY"
125+ <+> commaSeparated (renderSQL <$> srts)
126+
127+{- |
128+The `partitionBy` clause within `Squeal.PostgreSQL.Query.Over` divides the rows into groups,
129+or partitions, that share the same values of the `partitionBy` `Expression`(s).
130+For each row, the window function is computed across the rows that fall into
131+the same partition as the current row.
132+-}
133+partitionBy
134+ :: SOP.SListI bys
135+ => NP (Expression outer commons grp schemas params from) bys -- ^ partitions
136+ -> WindowDefinition outer commons grp schemas params from
137+partitionBy bys = WindowDefinition bys []
138+
139+{- |
140+A window function performs a calculation across a set of table rows
141+that are somehow related to the current row. This is comparable to the type
142+of calculation that can be done with an aggregate function.
143+However, window functions do not cause rows to become grouped into a single
144+output row like non-window aggregate calls would.
145+Instead, the rows retain their separate identities.
146+Behind the scenes, the window function is able to access more than
147+just the current row of the query result.
148+-}
149+newtype WindowFunction
150+ (outer :: FromType)
151+ (commons :: FromType)
152+ (grp :: Grouping)
153+ (schemas :: SchemasType)
154+ (params :: [NullityType])
155+ (from :: FromType)
156+ (ty :: NullityType)
157+ = UnsafeWindowFunction { renderWindowFunction :: ByteString }
158+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
159+
160+instance RenderSQL (WindowFunction outer commons grp schemas params from ty) where
161+ renderSQL = renderWindowFunction
162+
163+{- |
164+A @RankNType@ for window functions with no arguments.
165+-}
166+type WinFun0 x
167+ = forall outer commons grp schemas params from
168+ . WindowFunction outer commons grp schemas params from x
169+ -- ^ cannot reference aliases
170+
171+{- |
172+A @RankNType@ for window functions with 1 argument.
173+-}
174+type WinFun1 x y
175+ = forall outer commons grp schemas params from
176+ . Expression outer commons grp schemas params from x
177+ -- ^ input
178+ -> WindowFunction outer commons grp schemas params from y
179+ -- ^ output
180+
181+{- | A @RankNType@ for window functions with a fixed-length
182+list of heterogeneous arguments.
183+Use the `*:` operator to end your argument lists.
184+-}
185+type WinFunN xs y
186+ = forall outer commons grp schemas params from
187+ . NP (Expression outer commons grp schemas params from) xs
188+ -- ^ inputs
189+ -> WindowFunction outer commons grp schemas params from y
190+ -- ^ output
191+
192+-- | escape hatch for defining window functions
193+unsafeWindowFunction1 :: ByteString -> WinFun1 x y
194+unsafeWindowFunction1 fun x
195+ = UnsafeWindowFunction $ fun <> parenthesized (renderSQL x)
196+
197+-- | escape hatch for defining multi-argument window functions
198+unsafeWindowFunctionN :: SOP.SListI xs => ByteString -> WinFunN xs y
199+unsafeWindowFunctionN fun xs = UnsafeWindowFunction $ fun <>
200+ parenthesized (renderCommaSeparated renderSQL xs)
201+
202+{- | rank of the current row with gaps; same as `rowNumber` of its first peer
203+
204+>>> printSQL rank
205+rank()
206+-}
207+rank :: WinFun0 ('NotNull 'PGint8)
208+rank = UnsafeWindowFunction "rank()"
209+
210+{- | number of the current row within its partition, counting from 1
211+
212+>>> printSQL rowNumber
213+row_number()
214+-}
215+rowNumber :: WinFun0 ('NotNull 'PGint8)
216+rowNumber = UnsafeWindowFunction "row_number()"
217+
218+{- | rank of the current row without gaps; this function counts peer groups
219+
220+>>> printSQL denseRank
221+dense_rank()
222+-}
223+denseRank :: WinFun0 ('NotNull 'PGint8)
224+denseRank = UnsafeWindowFunction "dense_rank()"
225+
226+{- | relative rank of the current row: (rank - 1) / (total partition rows - 1)
227+
228+>>> printSQL percentRank
229+percent_rank()
230+-}
231+percentRank :: WinFun0 ('NotNull 'PGfloat8)
232+percentRank = UnsafeWindowFunction "percent_rank()"
233+
234+{- | cumulative distribution: (number of partition rows
235+preceding or peer with current row) / total partition rows
236+
237+>>> printSQL cumeDist
238+cume_dist()
239+-}
240+cumeDist :: WinFun0 ('NotNull 'PGfloat8)
241+cumeDist = UnsafeWindowFunction "cume_dist()"
242+
243+{- | integer ranging from 1 to the argument value,
244+dividing the partition as equally as possible
245+
246+>>> printSQL $ ntile 5
247+ntile(5)
248+-}
249+ntile :: WinFun1 ('NotNull 'PGint4) ('NotNull 'PGint4)
250+ntile = unsafeWindowFunction1 "ntile"
251+
252+{- | returns value evaluated at the row that is offset rows before the current
253+row within the partition; if there is no such row, instead return default
254+(which must be of the same type as value). Both offset and default are
255+evaluated with respect to the current row.
256+-}
257+lag :: WinFunN '[ty, 'NotNull 'PGint4, ty] ty
258+lag = unsafeWindowFunctionN "lag"
259+
260+{- | returns value evaluated at the row that is offset rows after the current
261+row within the partition; if there is no such row, instead return default
262+(which must be of the same type as value). Both offset and default are
263+evaluated with respect to the current row.
264+-}
265+lead :: WinFunN '[ty, 'NotNull 'PGint4, ty] ty
266+lead = unsafeWindowFunctionN "lead"
267+
268+{- | returns value evaluated at the row that is the
269+first row of the window frame
270+-}
271+firstValue :: WinFun1 ty ty
272+firstValue = unsafeWindowFunction1 "first_value"
273+
274+{- | returns value evaluated at the row that is the
275+last row of the window frame
276+-}
277+lastValue :: WinFun1 ty ty
278+lastValue = unsafeWindowFunction1 "last_value"
279+
280+{- | returns value evaluated at the row that is the nth
281+row of the window frame (counting from 1); null if no such row
282+-}
283+nthValue :: WinFunN '[null ty, 'NotNull 'PGint4] ('Null ty)
284+nthValue = unsafeWindowFunctionN "nth_value"
squeal-postgresql/src/Squeal/PostgreSQL/List.hsnew file+112
@@ -0,0 +1,112 @@
1+{-|
2+Module: Squeal.PostgreSQL.List
3+Description: List related types and functions
4+Copyright: (c) Eitan Chatav, 2019
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+Haskell singly-linked lists are very powerful. This module
9+provides functionality for type-level lists, heterogeneous
10+lists and type aligned lists.
11+-}
12+
13+{-# LANGUAGE
14+ DataKinds
15+ , FlexibleContexts
16+ , GADTs
17+ , LambdaCase
18+ , MultiParamTypeClasses
19+ , OverloadedStrings
20+ , PolyKinds
21+ , QuantifiedConstraints
22+ , RankNTypes
23+ , ScopedTypeVariables
24+ , TypeApplications
25+ , TypeFamilies
26+ , TypeOperators
27+ , UndecidableInstances
28+#-}
29+
30+module Squeal.PostgreSQL.List
31+ ( SOP.NP (..)
32+ , (*:)
33+ , Join
34+ , disjoin
35+ , Additional (..)
36+ , Path (..)
37+ , CFunctor (..)
38+ , CFoldable (..)
39+ , CFree (..)
40+ , Elem
41+ , In
42+ , Length
43+ ) where
44+
45+import Control.Category.Free
46+import Data.Function ((&))
47+import Data.Kind
48+import Data.Type.Bool
49+import GHC.TypeLits
50+
51+import Generics.SOP as SOP
52+
53+-- | `Join` is simply promoted `++` and is used in @JOIN@s in
54+-- `Squeal.PostgreSQL.Query.FromClause`s.
55+type family Join xs ys where
56+ Join '[] ys = ys
57+ Join (x ': xs) ys = x ': Join xs ys
58+
59+-- | `disjoin` is a utility function for splitting an `NP` list into pieces.
60+disjoin
61+ :: forall xs ys expr. SListI xs
62+ => NP expr (Join xs ys)
63+ -> (NP expr xs, NP expr ys)
64+disjoin = case sList @xs of
65+ SNil -> \ys -> (Nil, ys)
66+ SCons -> \(x :* xsys) ->
67+ case disjoin xsys of (xs,ys) -> (x :* xs, ys)
68+
69+-- | The `Additional` class is for appending
70+-- type-level list parameterized constructors such as `NP`,
71+-- `Squeal.PostgreSQL.Query.Selection`, and `Squeal.PostgreSQL.Query.FromClause`.
72+class Additional expr where
73+ also :: expr ys -> expr xs -> expr (Join xs ys)
74+instance Additional (NP expr) where
75+ also ys = \case
76+ Nil -> ys
77+ x :* xs -> x :* (xs & also ys)
78+
79+-- | A useful operator for ending an `NP` list of length at least 2 without `Nil`.
80+(*:) :: f x -> f y -> NP f '[x,y]
81+x *: y = x :* y :* Nil
82+infixl 9 *:
83+
84+-- | @Elem@ is a promoted `Data.List.elem`.
85+type family Elem x xs where
86+ Elem x '[] = 'False
87+ Elem x (x ': _) = 'True
88+ Elem x (_ ': x ': _) = 'True
89+ Elem x (_ ': _ ': x ': _) = 'True
90+ Elem x (_ ': _ ': _ ': x ': _) = 'True
91+ Elem x (_ ': _ ': _ ': _ ': x ': _) = 'True
92+ Elem x (_ ': _ ': _ ': _ ': _ ': x ': _) = 'True
93+ Elem x (_ ': xs) = Elem x xs
94+
95+-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.
96+type family In x xs :: Constraint where
97+ In x xs = If (Elem x xs) (() :: Constraint)
98+ (TypeError ('ShowType x ':<>: 'Text " is not in " ':<>: 'ShowType xs))
99+
100+{- | Calculate the `Length` of a type level list
101+
102+>>> :kind! Length '[Char,String,Bool,Double]
103+Length '[Char,String,Bool,Double] :: Nat
104+= 4
105+-}
106+type family Length (xs :: [k]) :: Nat where
107+ Length (_ ': _ ': _ ': _ ': _ : xs) = 5 + Length xs
108+ Length (_ ': _ ': _ ': _ : xs) = 4 + Length xs
109+ Length (_ ': _ ': _ : xs) = 3 + Length xs
110+ Length (_ ': _ : xs) = 2 + Length xs
111+ Length (_ : xs) = 1 + Length xs
112+ Length '[] = 0
squeal-postgresql/src/Squeal/PostgreSQL/Manipulation.hs+411−340
@@ -11,84 +11,139 @@ Squeal data manipulation language.
11{-# LANGUAGE
11{-# LANGUAGE
12 DeriveGeneric
12 DeriveGeneric
13 , FlexibleContexts
13 , FlexibleContexts
14+ , FlexibleInstances
14 , GADTs
15 , GADTs
15 , GeneralizedNewtypeDeriving
16 , GeneralizedNewtypeDeriving
16 , LambdaCase
17 , LambdaCase
18+ , MultiParamTypeClasses
17 , OverloadedStrings
19 , OverloadedStrings
20+ , PatternSynonyms
21+ , QuantifiedConstraints
18 , RankNTypes
22 , RankNTypes
23+ , ScopedTypeVariables
24+ , TypeApplications
25+ , TypeFamilies
19 , TypeInType
26 , TypeInType
20 , TypeOperators
27 , TypeOperators
28+ , UndecidableInstances
21#-}
29#-}
22
30
23module Squeal.PostgreSQL.Manipulation
31module Squeal.PostgreSQL.Manipulation
24 ( -- * Manipulation
32 ( -- * Manipulation
33+ Manipulation_
25− Manipulation (UnsafeManipulation, renderManipulation)
34+ , Manipulation (..)
26 , queryStatement
35 , queryStatement
27− , ColumnValue (..)
28− , ReturningClause (ReturningStar, Returning)
29− , ConflictClause (OnConflictDoRaise, OnConflictDoNothing, OnConflictDoUpdate)
30 -- * Insert
36 -- * Insert
31− , insertRows
37+ , insertInto
32− , insertRow
38+ , insertInto_
33− , insertRows_
34− , insertRow_
35− , insertQuery
36− , insertQuery_
37− , renderReturningClause
38− , renderConflictClause
39 -- * Update
39 -- * Update
40 , update
40 , update
41 , update_
41 , update_
42 -- * Delete
42 -- * Delete
43 , deleteFrom
43 , deleteFrom
44 , deleteFrom_
44 , deleteFrom_
45− -- * With
45+ -- * Clauses
46− , with
46+ , Optional (..)
47+ , QueryClause (..)
48+ , pattern Values_
49+ , ReturningClause (..)
50+ , pattern Returning_
51+ , ConflictClause (..)
52+ , ConflictTarget (..)
53+ , ConflictAction (..)
54+ , UsingClause (..)
47 ) where
55 ) where
48
56
49import Control.DeepSeq
57import Control.DeepSeq
50import Data.ByteString hiding (foldr)
58import Data.ByteString hiding (foldr)
51−import Data.Monoid
59+import Data.Kind (Type)
52
60
53import qualified Generics.SOP as SOP
61import qualified Generics.SOP as SOP
54import qualified GHC.Generics as GHC
62import qualified GHC.Generics as GHC
55
63
64+import Squeal.PostgreSQL.Alias
56import Squeal.PostgreSQL.Expression
65import Squeal.PostgreSQL.Expression
66+import Squeal.PostgreSQL.Expression.Logic
67+import Squeal.PostgreSQL.List
68+import Squeal.PostgreSQL.PG
57import Squeal.PostgreSQL.Render
69import Squeal.PostgreSQL.Render
58import Squeal.PostgreSQL.Query
70import Squeal.PostgreSQL.Query
59import Squeal.PostgreSQL.Schema
71import Squeal.PostgreSQL.Schema
60
72
73+-- $setup
74+-- >>> import Squeal.PostgreSQL
75+-- >>> import Data.Int
76+-- >>> import Data.Time
77+
61{- |
78{- |
62A `Manipulation` is a statement which may modify data in the database,
79A `Manipulation` is a statement which may modify data in the database,
63−but does not alter the schema. Examples are inserts, updates and deletes.
80+but does not alter its schemas. Examples are inserts, updates and deletes.
64A `Query` is also considered a `Manipulation` even though it does not modify data.
81A `Query` is also considered a `Manipulation` even though it does not modify data.
65
82
83+The general `Manipulation` type is parameterized by
84+
85+* @commons :: FromType@ - scope for all `common` table expressions,
86+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,
87+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,
88+* @row :: RowType@ - return type of the `Query`.
89+-}
90+newtype Manipulation
91+ (commons :: FromType)
92+ (schemas :: SchemasType)
93+ (params :: [NullityType])
94+ (columns :: RowType)
95+ = UnsafeManipulation { renderManipulation :: ByteString }
96+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
97+instance RenderSQL (Manipulation commons schemas params columns) where
98+ renderSQL = renderManipulation
99+instance With Manipulation where
100+ with Done manip = manip
101+ with ctes manip = UnsafeManipulation $
102+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL manip
103+
104+{- |
105+The top level `Manipulation_` type is parameterized by a @schemas@ `SchemasType`,
106+against which the query is type-checked, an input @parameters@ Haskell `Type`,
107+and an ouput row Haskell `Type`.
108+
109+A top-level `Manipulation_` can be run
110+using `Squeal.PostgreSQL.PQ.manipulateParams`, or if @parameters = ()@
111+using `Squeal.PostgreSQL.PQ.manipulate`.
112+
113+Generally, @parameters@ will be a Haskell tuple or record whose entries
114+may be referenced using positional
115+`Squeal.PostgreSQL.Expression.Parameter.parameter`s and @row@ will be a
116+Haskell record, whose entries will be targeted using overloaded labels.
117+
118+>>> :set -XDeriveAnyClass -XDerivingStrategies
119+>>> :{
120+data Row a b = Row { col1 :: a, col2 :: b }
121+ deriving stock (GHC.Generic)
122+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
123+:}
124+
66simple insert:
125simple insert:
67
126
127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]
128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
68>>> :{
129>>> :{
69let
130let
70− manipulation :: Manipulation
131+ manipulation :: Manipulation_ (Public Schema) () ()
71− '[ "tab" ::: 'Table ('[] :=>
72− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
73− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[] '[]
74 manipulation =
132 manipulation =
75− insertRow_ #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)
133+ insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))
76in printSQL manipulation
134in printSQL manipulation
77:}
135:}
78INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)
136INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)
79
137
80parameterized insert:
138parameterized insert:
81
139
140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]
141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
82>>> :{
142>>> :{
83let
143let
84− manipulation :: Manipulation
144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()
85− '[ "tab" ::: 'Table ('[] :=>
86− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
87− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]
88− '[ 'NotNull 'PGint4, 'NotNull 'PGint4 ] '[]
89 manipulation =
145 manipulation =
90− insertRow_ #tab
91− (Set (param @1) `As` #col1 :* Set (param @2) `As` #col2 :* Nil)
146+ insertInto_ #tab (Values_ (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2))
92in printSQL manipulation
147in printSQL manipulation
93:}
148:}
94INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))
149INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))
@@ -97,71 +152,48 @@ returning insert:
97
152
98>>> :{
153>>> :{
99let
154let
100− manipulation :: Manipulation
155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)
101− '[ "tab" ::: 'Table ('[] :=>
102− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
103− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[]
104− '["fromOnly" ::: 'NotNull 'PGint4]
105 manipulation =
156 manipulation =
106− insertRow #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)
157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))
107− OnConflictDoRaise (Returning (#col1 `As` #fromOnly :* Nil))
158+ OnConflictDoRaise (Returning (#col1 `as` #fromOnly))
108in printSQL manipulation
159in printSQL manipulation
109:}
160:}
110−INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT) RETURNING "col1" AS "fromOnly"
161+INSERT INTO "tab" ("col1", "col2") VALUES (2, 3) RETURNING "col1" AS "fromOnly"
111
162
112upsert:
163upsert:
113
164
165+>>> type CustomersColumns = '["name" ::: 'NoDef :=> 'NotNull 'PGtext, "email" ::: 'NoDef :=> 'NotNull 'PGtext]
166+>>> type CustomersConstraints = '["uq" ::: 'Unique '["name"]]
167+>>> type CustomersSchema = '["customers" ::: 'Table (CustomersConstraints :=> CustomersColumns)]
114>>> :{
168>>> :{
115let
169let
116− manipulation :: Manipulation
170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()
117− '[ "tab" ::: 'Table ('[] :=>
118− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
119− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]
120− '[] '[ "sum" ::: 'NotNull 'PGint4]
121 manipulation =
171 manipulation =
122− insertRows #tab
172+ insertInto #customers
123− (Set 2 `As` #col1 :* Set 4 `As` #col2 :* Nil)
173+ (Values_ (Set "John Smith" `as` #name :* Set "john@smith.com" `as` #email))
124− [Set 6 `As` #col1 :* Set 8 `As` #col2 :* Nil]
174+ (OnConflict (OnConstraint #uq)
125− (OnConflictDoUpdate
175+ (DoUpdate (Set (#excluded ! #email <> "; " <> #customers ! #email) `as` #email) []))
126− (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)
176+ (Returning_ Nil)
127− [#col1 .== #col2])
128− (Returning $ (#col1 + #col2) `As` #sum :* Nil)
129in printSQL manipulation
177in printSQL manipulation
130:}
178:}
131−INSERT INTO "tab" ("col1", "col2") VALUES (2, 4), (6, 8) ON CONFLICT DO UPDATE SET "col1" = 2 WHERE ("col1" = "col2") RETURNING ("col1" + "col2") AS "sum"
179+INSERT INTO "customers" ("name", "email") VALUES (E'John Smith', E'john@smith.com') ON CONFLICT ON CONSTRAINT "uq" DO UPDATE SET "email" = ("excluded"."email" || (E'; ' || "customers"."email"))
132
180
133query insert:
181query insert:
134
182
135>>> :{
183>>> :{
136let
184let
137− manipulation :: Manipulation
185+ manipulation :: Manipulation_ (Public Schema) () ()
138− '[ "tab" ::: 'Table ('[] :=>
186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))
139− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
140− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4
141− ])
142− , "other_tab" ::: 'Table ('[] :=>
143− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
144− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4
145− ])
146− ] '[] '[]
147− manipulation =
148− insertQuery_ #tab
149− (selectStar (from (table (#other_tab `As` #t))))
150in printSQL manipulation
187in printSQL manipulation
151:}
188:}
152−INSERT INTO "tab" SELECT * FROM "other_tab" AS "t"
189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"
153
190
154update:
191update:
155
192
156>>> :{
193>>> :{
157let
194let
158− manipulation :: Manipulation
195+ manipulation :: Manipulation_ (Public Schema) () ()
159− '[ "tab" ::: 'Table ('[] :=>
160− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
161− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[] '[]
162− manipulation =
163− update_ #tab (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)
196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)
164− (#col1 ./= #col2)
165in printSQL manipulation
197in printSQL manipulation
166:}
198:}
167UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")
199UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")
@@ -170,154 +202,178 @@ delete:
170
202
171>>> :{
203>>> :{
172let
204let
173− manipulation :: Manipulation
205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)
174− '[ "tab" ::: 'Table ('[] :=>
175− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
176− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[]
177− '[ "col1" ::: 'NotNull 'PGint4
178− , "col2" ::: 'NotNull 'PGint4 ]
179− manipulation = deleteFrom #tab (#col1 .== #col2) ReturningStar
206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)
180in printSQL manipulation
207in printSQL manipulation
181:}
208:}
182DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *
209DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *
183−-}
184−newtype Manipulation
185− (schema :: SchemaType)
186− (params :: [NullityType])
187− (columns :: RelationType)
188− = UnsafeManipulation { renderManipulation :: ByteString }
189− deriving (GHC.Generic,Show,Eq,Ord,NFData)
190
210
191−instance RenderSQL (Manipulation schema params columns) where
211+delete and using clause:
192− renderSQL = renderManipulation
212+
213+>>> :{
214+type Schema3 =
215+ '[ "tab" ::: 'Table ('[] :=> Columns)
216+ , "other_tab" ::: 'Table ('[] :=> Columns)
217+ , "third_tab" ::: 'Table ('[] :=> Columns) ]
218+:}
219+
220+>>> :{
221+let
222+ manipulation :: Manipulation_ (Public Schema3) () ()
223+ manipulation =
224+ deleteFrom #tab (Using (table #other_tab & also (table #third_tab)))
225+ ( (#tab ! #col2 .== #other_tab ! #col2)
226+ .&& (#tab ! #col2 .== #third_tab ! #col2) )
227+ (Returning_ Nil)
228+in printSQL manipulation
229+:}
230+DELETE FROM "tab" USING "other_tab" AS "other_tab", "third_tab" AS "third_tab" WHERE (("tab"."col2" = "other_tab"."col2") AND ("tab"."col2" = "third_tab"."col2"))
231+
232+with manipulation:
233+
234+>>> type ProductsColumns = '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]
235+>>> type ProductsSchema = '["products" ::: 'Table ('[] :=> ProductsColumns), "products_deleted" ::: 'Table ('[] :=> ProductsColumns)]
236+>>> :{
237+let
238+ manipulation :: Manipulation_ (Public ProductsSchema) (Only Day) ()
239+ manipulation = with
240+ (deleteFrom #products NoUsing (#date .< param @1) (Returning Star) `as` #del)
241+ (insertInto_ #products_deleted (Subquery (select Star (from (common #del)))))
242+in printSQL manipulation
243+:}
244+WITH "del" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "del" AS "del"
245+-}
246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where
247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)
193
248
194-- | Convert a `Query` into a `Manipulation`.
249-- | Convert a `Query` into a `Manipulation`.
195queryStatement
250queryStatement
196− :: Query schema params columns
251+ :: Query '[] commons schemas params columns
252+ -- ^ `Query` to embed as a `Manipulation`
197− -> Manipulation schema params columns
253+ -> Manipulation commons schemas params columns
198−queryStatement q = UnsafeManipulation $ renderQuery q
254+queryStatement q = UnsafeManipulation $ renderSQL q
199
255
200{-----------------------------------------
256{-----------------------------------------
201INSERT statements
257INSERT statements
202-----------------------------------------}
258-----------------------------------------}
203
259
204−-- | Insert multiple rows.
260+{- |
205−--
206−-- When a table is created, it contains no data. The first thing to do
261+When a table is created, it contains no data. The first thing to do
207−-- before a database can be of much use is to insert data. Data is
262+before a database can be of much use is to insert data. Data is
208−-- conceptually inserted one row at a time. Of course you can also insert
263+conceptually inserted one row at a time. Of course you can also insert
209−-- more than one row, but there is no way to insert less than one row.
264+more than one row, but there is no way to insert less than one row.
210−-- Even if you know only some column values, a complete row must be created.
265+Even if you know only some column values, a complete row must be created.
211−insertRows
266+-}
212− :: ( SOP.SListI columns
267+insertInto
213− , SOP.SListI results
268+ :: ( Has sch schemas schema
214− , Has tab schema ('Table table)
215− , columns ~ TableToColumns table )
216− => Alias tab -- ^ table to insert into
217− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert
218− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert
219− -> ConflictClause schema columns params
220− -- ^ what to do in case of constraint conflict
221− -> ReturningClause schema columns params results -- ^ results to return
222− -> Manipulation schema params results
223−insertRows tab rw rws conflict returning = UnsafeManipulation $
224− "INSERT" <+> "INTO" <+> renderAlias tab
225− <+> parenthesized (renderCommaSeparated renderAliasPart rw)
226− <+> "VALUES"
227− <+> commaSeparated
228− ( parenthesized
229− . renderCommaSeparated renderColumnValuePart <$> rw:rws )
230− <> renderConflictClause conflict
231− <> renderReturningClause returning
232− where
233− renderAliasPart, renderColumnValuePart
234− :: Aliased (ColumnValue schema '[] params) ty -> ByteString
235− renderAliasPart (_ `As` name) = renderAlias name
236− renderColumnValuePart (value `As` _) = case value of
237− Default -> "DEFAULT"
238− Set expression -> renderExpression expression
239−
240−-- | Insert a single row.
241−insertRow
242− :: ( SOP.SListI columns
243− , SOP.SListI results
244− , Has tab schema ('Table table)
245− , columns ~ TableToColumns table )
246− => Alias tab -- ^ table to insert into
247− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert
248− -> ConflictClause schema columns params
249− -- ^ what to do in case of constraint conflict
250− -> ReturningClause schema columns params results -- ^ results to return
251− -> Manipulation schema params results
252−insertRow tab rw = insertRows tab rw []
253−
254−-- | Insert multiple rows returning `Nil` and raising an error on conflicts.
255−insertRows_
256− :: ( SOP.SListI columns
257− , Has tab schema ('Table table)
258− , columns ~ TableToColumns table )
259− => Alias tab -- ^ table to insert into
260− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert
261− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert
262− -> Manipulation schema params '[]
263−insertRows_ tab rw rws =
264− insertRows tab rw rws OnConflictDoRaise (Returning Nil)
265−
266−-- | Insert a single row returning `Nil` and raising an error on conflicts.
267−insertRow_
268− :: ( SOP.SListI columns
269− , Has tab schema ('Table table)
270− , columns ~ TableToColumns table )
271− => Alias tab -- ^ table to insert into
272− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert
273− -> Manipulation schema params '[]
274−insertRow_ tab rw = insertRow tab rw OnConflictDoRaise (Returning Nil)
275−
276−-- | Insert a `Query`.
277−insertQuery
278− :: ( SOP.SListI columns
279− , SOP.SListI results
280 , Has tab schema ('Table table)
269 , Has tab schema ('Table table)
281− , columns ~ TableToColumns table )
270+ , columns ~ TableToColumns table
271+ , row0 ~ TableToRow table
272+ , SOP.SListI columns
273+ , SOP.SListI row1 )
274+ => QualifiedAlias sch tab
275+ -- ^ table
276+ -> QueryClause commons schemas params columns
282− => Alias tab -- ^ table to insert into
277+ -- ^ what to insert
283− -> Query schema params (ColumnsToRelation columns)
284− -> ConflictClause schema columns params
278+ -> ConflictClause tab commons schemas params table
285− -- ^ what to do in case of constraint conflict
279+ -- ^ what to do in case of conflict
286− -> ReturningClause schema columns params results -- ^ results to return
280+ -> ReturningClause commons schemas params '[tab ::: row0] row1
281+ -- ^ what to return
287− -> Manipulation schema params results
282+ -> Manipulation commons schemas params row1
288−insertQuery tab query conflict returning = UnsafeManipulation $
283+insertInto tab qry conflict ret = UnsafeManipulation $
289− "INSERT" <+> "INTO" <+> renderAlias tab
284+ "INSERT" <+> "INTO" <+> renderSQL tab
290− <+> renderQuery query
285+ <+> renderSQL qry
291− <> renderConflictClause conflict
286+ <> renderSQL conflict
292− <> renderReturningClause returning
287+ <> renderSQL ret
293−
288+
294−-- | Insert a `Query` returning `Nil` and raising an error on conflicts.
289+-- | Like `insertInto` but with `OnConflictDoRaise` and `no` `ReturningClause`.
295−insertQuery_
290+insertInto_
296− :: ( SOP.SListI columns
291+ :: ( Has sch schemas schema
297 , Has tab schema ('Table table)
292 , Has tab schema ('Table table)
298− , columns ~ TableToColumns table )
293+ , columns ~ TableToColumns table
299− => Alias tab -- ^ table to insert into
294+ , row ~ TableToRow table
300− -> Query schema params (ColumnsToRelation columns)
295+ , SOP.SListI columns )
296+ => QualifiedAlias sch tab
297+ -- ^ table
298+ -> QueryClause commons schemas params columns
299+ -- ^ what to insert
301− -> Manipulation schema params '[]
300+ -> Manipulation commons schemas params '[]
302−insertQuery_ tab query =
301+insertInto_ tab qry =
303− insertQuery tab query OnConflictDoRaise (Returning Nil)
302+ insertInto tab qry OnConflictDoRaise (Returning_ Nil)
304−
303+
305−-- | `ColumnValue`s are values to insert or update in a row.
304+-- | A `QueryClause` describes what to `insertInto` a table.
306−-- `Same` updates with the same value.
305+data QueryClause commons schemas params columns where
307−-- `Default` inserts or updates with the @DEFAULT@ value.
306+ Values
308−-- `Set` sets a value to be an `Expression`, which can refer to
307+ :: SOP.SListI columns
309−-- existing value in the row for an update.
308+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns
310−data ColumnValue
309+ -- ^ row of values
311− (schema :: SchemaType)
310+ -> [NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns]
312− (columns :: RelationType)
311+ -- ^ additional rows of values
313− (params :: [NullityType])
312+ -> QueryClause commons schemas params columns
314− (ty :: ColumnType)
313+ Select
315− where
314+ :: SOP.SListI columns
316− Same :: ColumnValue schema (column ': columns) params ty
315+ => NP (Aliased (Optional (Expression '[] commons grp schemas params from))) columns
317− Default :: ColumnValue schema columns params ('Def :=> ty)
316+ -- ^ row of values
318− Set
317+ -> TableExpression '[] commons grp schemas params from
319− :: (forall table. Expression schema '[table ::: columns] 'Ungrouped params ty)
318+ -- ^ from a table expression
320− -> ColumnValue schema columns params (constraint :=> ty)
319+ -> QueryClause commons schemas params columns
320+ Subquery
321+ :: ColumnsToRow columns ~ row
322+ => Query '[] commons schemas params row
323+ -- ^ subquery to insert
324+ -> QueryClause commons schemas params columns
325+
326+instance RenderSQL (QueryClause commons schemas params columns) where
327+ renderSQL = \case
328+ Values row0 rows ->
329+ parenthesized (renderCommaSeparated renderSQLPart row0)
330+ <+> "VALUES"
331+ <+> commaSeparated
332+ ( parenthesized
333+ . renderCommaSeparated renderValuePart <$> row0 : rows )
334+ Select row0 tab ->
335+ parenthesized (renderCommaSeparatedMaybe renderSQLPartMaybe row0)
336+ <+> "SELECT"
337+ <+> renderCommaSeparatedMaybe renderValuePartMaybe row0
338+ <+> renderSQL tab
339+ Subquery qry -> renderQuery qry
340+ where
341+ renderSQLPartMaybe, renderValuePartMaybe
342+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column
343+ -> Maybe ByteString
344+ renderSQLPartMaybe = \case
345+ Default `As` _ -> Nothing
346+ Set _ `As` name -> Just $ renderSQL name
347+ renderValuePartMaybe = \case
348+ Default `As` _ -> Nothing
349+ Set value `As` _ -> Just $ renderExpression value
350+ renderSQLPart, renderValuePart
351+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column
352+ -> ByteString
353+ renderSQLPart (_ `As` name) = renderSQL name
354+ renderValuePart (value `As` _) = renderSQL value
355+
356+-- | `Values_` describes a single `NP` list of `Aliased` `Optional` `Expression`s
357+-- whose `ColumnsType` must match the tables'.
358+pattern Values_
359+ :: SOP.SListI columns
360+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns
361+ -- ^ row of values
362+ -> QueryClause commons schemas params columns
363+pattern Values_ vals = Values vals []
364+
365+-- | `Optional` is either `Default` or a value, parameterized by an appropriate
366+-- `ColumnConstraint`.
367+data Optional expr ty where
368+ -- | Use the `Default` value for a column.
369+ Default :: Optional expr ('Def :=> ty)
370+ -- | `Set` a value for a column.
371+ Set :: expr ty -> Optional expr (def :=> ty)
372+
373+instance (forall x. RenderSQL (expr x)) => RenderSQL (Optional expr ty) where
374+ renderSQL = \case
375+ Default -> "DEFAULT"
376+ Set expr -> renderSQL expr
321
377
322-- | A `ReturningClause` computes and return value(s) based
378-- | A `ReturningClause` computes and return value(s) based
323-- on each row actually inserted, updated or deleted. This is primarily
379-- on each row actually inserted, updated or deleted. This is primarily
@@ -325,72 +381,100 @@ data ColumnValue
325-- serial sequence number. However, any expression using the table's columns
381-- serial sequence number. However, any expression using the table's columns
326-- is allowed. Only rows that were successfully inserted or updated or
382-- is allowed. Only rows that were successfully inserted or updated or
327-- deleted will be returned. For example, if a row was locked
383-- deleted will be returned. For example, if a row was locked
328−-- but not updated because an `OnConflictDoUpdate` condition was not satisfied,
384+-- but not updated because an `OnConflict` `DoUpdate` condition was not satisfied,
329−-- the row will not be returned. `ReturningStar` will return all columns
385+-- the row will not be returned. `Returning` `Star` will return all columns
330−-- in the row. Use @Returning Nil@ in the common case where no return
386+-- in the row. Use `Returning` `Nil` in the common case where no return
331-- values are desired.
387-- values are desired.
332−data ReturningClause
388+newtype ReturningClause commons schemas params from row =
333− (schema :: SchemaType)
389+ Returning (Selection '[] commons 'Ungrouped schemas params from row)
334− (columns :: ColumnsType)
390+
335− (params :: [NullityType])
391+instance RenderSQL (ReturningClause commons schemas params from row) where
336− (results :: RelationType)
392+ renderSQL = \case
337− where
338− ReturningStar
339− :: results ~ ColumnsToRelation columns
340− => ReturningClause schema columns params results
341− Returning
342− :: rel ~ ColumnsToRelation columns
343− => NP (Aliased (Expression schema '[table ::: rel] 'Ungrouped params)) results
344− -> ReturningClause schema columns params results
345−
346−-- | Render a `ReturningClause`.
347−renderReturningClause
348− :: SOP.SListI results
349− => ReturningClause schema params columns results
350− -> ByteString
351−renderReturningClause = \case
352− ReturningStar -> " RETURNING *"
353− Returning Nil -> ""
393+ Returning (List Nil) -> ""
354− Returning results -> " RETURNING"
394+ Returning selection -> " RETURNING" <+> renderSQL selection
355− <+> renderCommaSeparated (renderAliasedAs renderExpression) results
395+
396+-- | `Returning` a `List`
397+pattern Returning_
398+ :: SOP.SListI row
399+ => NP (Aliased (Expression '[] commons 'Ungrouped schemas params from)) row
400+ -- ^ row of values
401+ -> ReturningClause commons schemas params from row
402+pattern Returning_ list = Returning (List list)
356
403
357-- | A `ConflictClause` specifies an action to perform upon a constraint
404-- | A `ConflictClause` specifies an action to perform upon a constraint
358-- violation. `OnConflictDoRaise` will raise an error.
405-- violation. `OnConflictDoRaise` will raise an error.
359−-- `OnConflictDoNothing` simply avoids inserting a row.
406+-- `OnConflict` `DoNothing` simply avoids inserting a row.
360−-- `OnConflictDoUpdate` updates the existing row that conflicts with the row
407+-- `OnConflict` `DoUpdate` updates the existing row that conflicts with the row
361-- proposed for insertion.
408-- proposed for insertion.
362−data ConflictClause (schema :: SchemaType) (columns :: ColumnsType) params where
409+data ConflictClause tab commons schemas params table where
363− OnConflictDoRaise :: ConflictClause schema columns params
410+ OnConflictDoRaise :: ConflictClause tab commons schemas params table
364− OnConflictDoNothing :: ConflictClause schema columns params
411+ OnConflict
365− OnConflictDoUpdate
412+ :: ConflictTarget constraints
366− :: NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns
413+ -- ^ conflict target
367− -> [Condition schema '[table ::: ColumnsToRelation columns] 'Ungrouped params]
414+ -> ConflictAction tab commons schemas params columns
415+ -- ^ conflict action
368− -> ConflictClause schema columns params
416+ -> ConflictClause tab commons schemas params (constraints :=> columns)
369
417
370-- | Render a `ConflictClause`.
418-- | Render a `ConflictClause`.
371−renderConflictClause
419+instance SOP.SListI (TableToColumns table)
372− :: SOP.SListI columns
420+ => RenderSQL (ConflictClause tab commons schemas params table) where
373− => ConflictClause schema columns params
421+ renderSQL = \case
422+ OnConflictDoRaise -> ""
423+ OnConflict target action -> " ON CONFLICT"
424+ <+> renderSQL target <+> renderSQL action
425+
426+{- |
427+`ConflictAction` specifies an alternative `OnConflict` action.
428+It can be either `DoNothing`, or a `DoUpdate` clause specifying
429+the exact details of the `update` action to be performed in case of a conflict.
430+The `Set` and WHERE `Condition`s in `OnConflict` `DoUpdate` have access to the
431+existing row using the table's name (or an alias), and to rows proposed
432+for insertion using the special @#excluded@ table.
433+`OnConflict` `DoNothing` simply avoids inserting a row as its alternative action.
434+`OnConflict` `DoUpdate` updates the existing row that conflicts
435+with the row proposed for insertion as its alternative action.
436+-}
437+data ConflictAction tab commons schemas params columns where
438+ DoNothing :: ConflictAction tab commons schemas params columns
439+ DoUpdate
440+ :: ( row ~ ColumnsToRow columns
441+ , SOP.SListI columns
442+ , columns ~ (col0 ': cols)
443+ , SOP.All (HasIn columns) subcolumns
444+ , AllUnique subcolumns )
445+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]))) subcolumns
446+ -> [Condition '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]]
447+ -- ^ WHERE `Condition`s
448+ -> ConflictAction tab commons schemas params columns
449+
450+instance RenderSQL (ConflictAction tab commons schemas params columns) where
451+ renderSQL = \case
452+ DoNothing -> "DO NOTHING"
453+ DoUpdate updates whs'
454+ -> "DO UPDATE SET"
455+ <+> renderCommaSeparated renderUpdate updates
456+ <> case whs' of
457+ [] -> ""
458+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)
459+
460+renderUpdate
461+ :: (forall x. RenderSQL (expr x))
462+ => Aliased (Optional expr) ty
374 -> ByteString
463 -> ByteString
375−renderConflictClause = \case
464+renderUpdate (expr `As` col) = renderSQL col <+> "=" <+> renderSQL expr
376− OnConflictDoRaise -> ""
465+
377− OnConflictDoNothing -> " ON CONFLICT DO NOTHING"
466+-- | A `ConflictTarget` specifies the constraint violation that triggers a
378− OnConflictDoUpdate updates whs'
467+-- `ConflictAction`.
379− -> " ON CONFLICT DO UPDATE SET"
468+data ConflictTarget constraints where
380− <+> renderCommaSeparatedMaybe renderUpdate updates
469+ OnConstraint
381− <> case whs' of
470+ :: Has con constraints constraint
382− [] -> ""
471+ => Alias con
383− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)
472+ -> ConflictTarget constraints
384− where
473+
385− renderUpdate
474+-- | Render a `ConflictTarget`
386− :: Aliased (ColumnValue schema columns params) column
475+instance RenderSQL (ConflictTarget constraints) where
387− -> Maybe ByteString
476+ renderSQL (OnConstraint con) =
388− renderUpdate = \case
477+ "ON" <+> "CONSTRAINT" <+> renderSQL con
389− Same `As` _ -> Nothing
390− Default `As` column -> Just $
391− renderAlias column <+> "=" <+> "DEFAULT"
392− Set expression `As` column -> Just $
393− renderAlias column <+> "=" <+> renderExpression expression
394
478
395{-----------------------------------------
479{-----------------------------------------
396UPDATE statements
480UPDATE statements
@@ -400,108 +484,95 @@ UPDATE statements
400-- in all rows that satisfy the condition.
484-- in all rows that satisfy the condition.
401update
485update
402 :: ( SOP.SListI columns
486 :: ( SOP.SListI columns
403− , SOP.SListI results
487+ , SOP.SListI row1
488+ , Has sch schemas schema
404 , Has tab schema ('Table table)
489 , Has tab schema ('Table table)
490+ , row0 ~ TableToRow table
405− , columns ~ TableToColumns table )
491+ , columns ~ TableToColumns table
492+ , SOP.All (HasIn columns) subcolumns
493+ , AllUnique subcolumns )
406− => Alias tab -- ^ table to update
494+ => QualifiedAlias sch tab -- ^ table to update
407− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns
495+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row0]))) subcolumns
408 -- ^ modified values to replace old values
496 -- ^ modified values to replace old values
409− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params
497+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row0]
410 -- ^ condition under which to perform update on a row
498 -- ^ condition under which to perform update on a row
411− -> ReturningClause schema columns params results -- ^ results to return
499+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return
412− -> Manipulation schema params results
500+ -> Manipulation commons schemas params row1
413update tab columns wh returning = UnsafeManipulation $
501update tab columns wh returning = UnsafeManipulation $
414 "UPDATE"
502 "UPDATE"
415− <+> renderAlias tab
503+ <+> renderSQL tab
416 <+> "SET"
504 <+> "SET"
417− <+> renderCommaSeparatedMaybe renderUpdate columns
505+ <+> renderCommaSeparated renderUpdate columns
418− <+> "WHERE" <+> renderExpression wh
506+ <+> "WHERE" <+> renderSQL wh
419− <> renderReturningClause returning
507+ <> renderSQL returning
420− where
421− renderUpdate
422− :: Aliased (ColumnValue schema columns params) column
423− -> Maybe ByteString
424− renderUpdate = \case
425− Same `As` _ -> Nothing
426− Default `As` column -> Just $
427− renderAlias column <+> "=" <+> "DEFAULT"
428− Set expression `As` column -> Just $
429− renderAlias column <+> "=" <+> renderExpression expression
430
508
431-- | Update a row returning `Nil`.
509-- | Update a row returning `Nil`.
432update_
510update_
433 :: ( SOP.SListI columns
511 :: ( SOP.SListI columns
512+ , Has sch schemas schema
434 , Has tab schema ('Table table)
513 , Has tab schema ('Table table)
514+ , row ~ TableToRow table
435− , columns ~ TableToColumns table )
515+ , columns ~ TableToColumns table
516+ , SOP.All (HasIn columns) subcolumns
517+ , AllUnique subcolumns )
436− => Alias tab -- ^ table to update
518+ => QualifiedAlias sch tab -- ^ table to update
437− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns
519+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row]))) subcolumns
438 -- ^ modified values to replace old values
520 -- ^ modified values to replace old values
439− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params
521+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]
440 -- ^ condition under which to perform update on a row
522 -- ^ condition under which to perform update on a row
441− -> Manipulation schema params '[]
523+ -> Manipulation commons schemas params '[]
442−update_ tab columns wh = update tab columns wh (Returning Nil)
524+update_ tab columns wh = update tab columns wh (Returning_ Nil)
443
525
444{-----------------------------------------
526{-----------------------------------------
445DELETE statements
527DELETE statements
446-----------------------------------------}
528-----------------------------------------}
447
529
530+-- | Specify additional tables with `Using`
531+-- an `also` list of table expressions, allowing columns
532+-- from other tables to appear in the WHERE condition.
533+-- This is similar to the list of tables that can be specified
534+-- in the FROM Clause of a SELECT statement;
535+-- for example, an alias for the table name can be specified.
536+-- Do not repeat the target table in the `Using` list,
537+-- unless you wish to set up a self-join.
538+-- `NoUsing` if no additional tables are to be used.
539+data UsingClause commons schemas params from where
540+ NoUsing :: UsingClause commons schemas params '[]
541+ Using
542+ :: FromClause '[] commons schemas params from
543+ -- ^ what to use
544+ -> UsingClause commons schemas params from
545+
448−-- | Delete rows of a table.
546+-- | Delete rows from a table.
449deleteFrom
547deleteFrom
450− :: ( SOP.SListI results
548+ :: ( SOP.SListI row1
549+ , Has sch schemas schema
451 , Has tab schema ('Table table)
550 , Has tab schema ('Table table)
551+ , row0 ~ TableToRow table
452 , columns ~ TableToColumns table )
552 , columns ~ TableToColumns table )
453− => Alias tab -- ^ table to delete from
553+ => QualifiedAlias sch tab -- ^ table to delete from
554+ -> UsingClause commons schemas params from
454− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params
555+ -> Condition '[] commons 'Ungrouped schemas params (tab ::: row0 ': from)
455 -- ^ condition under which to delete a row
556 -- ^ condition under which to delete a row
456− -> ReturningClause schema columns params results -- ^ results to return
557+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return
457− -> Manipulation schema params results
558+ -> Manipulation commons schemas params row1
458−deleteFrom tab wh returning = UnsafeManipulation $
559+deleteFrom tab using wh returning = UnsafeManipulation $
459− "DELETE FROM" <+> renderAlias tab
560+ "DELETE FROM"
460− <+> "WHERE" <+> renderExpression wh
561+ <+> renderSQL tab
461− <> renderReturningClause returning
562+ <> case using of
563+ NoUsing -> ""
564+ Using tables -> " USING" <+> renderSQL tables
565+ <+> "WHERE" <+> renderSQL wh
566+ <> renderSQL returning
462
567
463-- | Delete rows returning `Nil`.
568-- | Delete rows returning `Nil`.
464deleteFrom_
569deleteFrom_
570+ :: ( Has sch schemas schema
465− :: ( Has tab schema ('Table table)
571+ , Has tab schema ('Table table)
572+ , row ~ TableToRow table
466 , columns ~ TableToColumns table )
573 , columns ~ TableToColumns table )
467− => Alias tab -- ^ table to delete from
574+ => QualifiedAlias sch tab -- ^ table to delete from
468− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params
575+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]
469 -- ^ condition under which to delete a row
576 -- ^ condition under which to delete a row
470− -> Manipulation schema params '[]
577+ -> Manipulation commons schemas params '[]
471−deleteFrom_ tab wh = deleteFrom tab wh (Returning Nil)
578+deleteFrom_ tab wh = deleteFrom tab NoUsing wh (Returning_ Nil)
472−
473−{-----------------------------------------
474−WITH statements
475−-----------------------------------------}
476−
477−-- | `with` provides a way to write auxiliary statements for use in a larger statement.
478−-- These statements, which are often referred to as Common Table Expressions or CTEs,
479−-- can be thought of as defining temporary tables that exist just for one statement.
480−--
481−-- >>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]
482−--
483−-- >>> :{
484−-- let
485−-- manipulation :: Manipulation '["products" ::: 'Table ProductsTable, "products_deleted" ::: 'Table ProductsTable] '[ 'NotNull 'PGdate] '[]
486−-- manipulation = with
487−-- (deleteFrom #products (#date .< param @1) ReturningStar `As` #deleted_rows :* Nil)
488−-- (insertQuery_ #products_deleted (selectStar (from (view (#deleted_rows `As` #t)))))
489−-- in printSQL manipulation
490−-- :}
491−-- WITH "deleted_rows" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "deleted_rows" AS "t"
492−with
493− :: SOP.SListI commons
494− => NP (Aliased (Manipulation schema params)) commons
495− -- ^ common table expressions
496− -> Manipulation (With commons schema) params results
497− -> Manipulation schema params results
498−with commons manipulation = UnsafeManipulation $
499− "WITH" <+> renderCommaSeparated renderCommon commons
500− <+> renderManipulation manipulation
501− where
502− renderCommon
503− :: Aliased (Manipulation schema params) common
504− -> ByteString
505− renderCommon (common `As` alias) =
506− renderAlias alias <+> "AS" <+>
507− parenthesized (renderManipulation common)
squeal-postgresql/src/Squeal/PostgreSQL/Migration.hs+347−215
@@ -8,8 +8,13 @@ Stability: experimental
8This module defines a `Migration` type to safely
8This module defines a `Migration` type to safely
9change the schema of your database over time. Let's see an example!
9change the schema of your database over time. Let's see an example!
10
10
11+First turn on some extensions.
12+
11>>> :set -XDataKinds -XOverloadedLabels
13>>> :set -XDataKinds -XOverloadedLabels
12>>> :set -XOverloadedStrings -XFlexibleContexts -XTypeOperators
14>>> :set -XOverloadedStrings -XFlexibleContexts -XTypeOperators
15+
16+Next, let's define our `TableType`s.
17+
13>>> :{
18>>> :{
14type UsersTable =
19type UsersTable =
15 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
20 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
@@ -20,7 +25,7 @@ type UsersTable =
20
25
21>>> :{
26>>> :{
22type EmailsTable =
27type EmailsTable =
23− '[ "pk_emails" ::: 'PrimaryKey '["id"]
28+ '[ "pk_emails" ::: 'PrimaryKey '["id"]
24 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
29 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
25 ] :=>
30 ] :=>
26 '[ "id" ::: 'Def :=> 'NotNull 'PGint4
31 '[ "id" ::: 'Def :=> 'NotNull 'PGint4
@@ -29,248 +34,293 @@ type EmailsTable =
29 ]
34 ]
30:}
35:}
31
36
37+Now we can define some `Migration`s to make our tables.
38+
32>>> :{
39>>> :{
33let
40let
34− makeUsers :: Migration IO '[] '["users" ::: 'Table UsersTable]
41+ makeUsers :: Migration Definition (Public '[]) '["public" ::: '["users" ::: 'Table UsersTable]]
35 makeUsers = Migration
42 makeUsers = Migration
36 { name = "make users table"
43 { name = "make users table"
37− , up = void . define $
38− createTable #users
44+ , up = createTable #users
39− ( serial `As` #id :*
45+ ( serial `as` #id :*
40− (text & notNullable) `As` #name :* Nil )
46+ notNullable text `as` #name )
41− ( primaryKey #id `As` #pk_users :* Nil )
47+ ( primaryKey #id `as` #pk_users )
42− , down = void . define $ dropTable #users
48+ , down = dropTable #users
43 }
49 }
44:}
50:}
45
51
46>>> :{
52>>> :{
47let
53let
48− makeEmails :: Migration IO '["users" ::: 'Table UsersTable]
54+ makeEmails :: Migration Definition '["public" ::: '["users" ::: 'Table UsersTable]]
49− '["users" ::: 'Table UsersTable, "emails" ::: 'Table EmailsTable]
55+ '["public" ::: '["users" ::: 'Table UsersTable, "emails" ::: 'Table EmailsTable]]
50 makeEmails = Migration
56 makeEmails = Migration
51 { name = "make emails table"
57 { name = "make emails table"
52− , up = void . define $
53− createTable #emails
58+ , up = createTable #emails
54− ( serial `As` #id :*
59+ ( serial `as` #id :*
55− (int & notNullable) `As` #user_id :*
60+ notNullable int `as` #user_id :*
56− (text & nullable) `As` #email :* Nil )
61+ nullable text `as` #email )
57− ( primaryKey #id `As` #pk_emails :*
62+ ( primaryKey #id `as` #pk_emails :*
58 foreignKey #user_id #users #id
63 foreignKey #user_id #users #id
59− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
64+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
60− , down = void . define $ dropTable #emails
65+ , down = dropTable #emails
61 }
66 }
62:}
67:}
63
68
64−Now that we have a couple migrations we can chain them together.
69+Now that we have a couple migrations we can chain them together into a `Path`.
65
70
66>>> let migrations = makeUsers :>> makeEmails :>> Done
71>>> let migrations = makeUsers :>> makeEmails :>> Done
67
72
68−>>> :{
73+Now run the migrations.
69−let
70− numMigrations
71− :: Has "schema_migrations" schema ('Table MigrationsTable)
72− => PQ schema schema IO ()
73− numMigrations = do
74− result <- runQuery (selectStar (from (table (#schema_migrations `As` #m))))
75− num <- ntuples result
76− liftBase $ print num
77−:}
78
74
75+>>> import Control.Monad.IO.Class
79>>> :{
76>>> :{
80withConnection "host=localhost port=5432 dbname=exampledb" $
77withConnection "host=localhost port=5432 dbname=exampledb" $
81 manipulate (UnsafeManipulation "SET client_min_messages TO WARNING;")
78 manipulate (UnsafeManipulation "SET client_min_messages TO WARNING;")
82 -- suppress notices
79 -- suppress notices
80+ & pqThen (liftIO (putStrLn "Migrate"))
83 & pqThen (migrateUp migrations)
81 & pqThen (migrateUp migrations)
84− & pqThen numMigrations
82+ & pqThen (liftIO (putStrLn "Rollback"))
85 & pqThen (migrateDown migrations)
83 & pqThen (migrateDown migrations)
86− & pqThen numMigrations
87:}
84:}
88−Row 2
85+Migrate
89−Row 0
86+Rollback
87+
88+We can also create a simple executable using `defaultMain`.
89+
90+>>> let main = defaultMain "host=localhost port=5432 dbname=exampledb" migrations
91+
92+>>> withArgs [] main
93+Invalid command: "". Use:
94+migrate to run all available migrations
95+rollback to rollback all available migrations
96+status to display migrations run and migrations left to run
97+
98+>>> withArgs ["status"] main
99+Migrations already run:
100+ None
101+Migrations left to run:
102+ - make users table
103+ - make emails table
104+
105+>>> withArgs ["migrate"] main
106+Migrations already run:
107+ - make users table
108+ - make emails table
109+Migrations left to run:
110+ None
111+
112+>>> withArgs ["rollback"] main
113+Migrations already run:
114+ None
115+Migrations left to run:
116+ - make users table
117+ - make emails table
118+
119+In addition to enabling `Migration`s using pure SQL `Definition`s for
120+the `up` and `down` instructions, you can also perform impure `IO` actions
121+by using a `Migration`s over the `Terminally` `PQ` `IO` category.
90-}
122-}
91
123
92{-# LANGUAGE
124{-# LANGUAGE
93 DataKinds
125 DataKinds
126+ , DeriveGeneric
127+ , FlexibleContexts
128+ , FlexibleInstances
94 , GADTs
129 , GADTs
95 , LambdaCase
130 , LambdaCase
96− , PolyKinds
97 , OverloadedLabels
131 , OverloadedLabels
132+ , OverloadedStrings
133+ , PolyKinds
134+ , QuantifiedConstraints
135+ , RankNTypes
98 , TypeApplications
136 , TypeApplications
99− , FlexibleContexts
100 , TypeOperators
137 , TypeOperators
101#-}
138#-}
102
139
103module Squeal.PostgreSQL.Migration
140module Squeal.PostgreSQL.Migration
104 ( -- * Migration
141 ( -- * Migration
105 Migration (..)
142 Migration (..)
106− , migrateUp
143+ , Migratory (..)
107− , migrateDown
144+ , Terminally (..)
108− -- * Aligned lists
145+ , terminally
109− , AlignedList (..)
146+ , pureMigration
110− , single
111− -- * Migration table
112 , MigrationsTable
147 , MigrationsTable
113− , createMigrations
148+ , defaultMain
114− , insertMigration
115− , deleteMigration
116− , selectMigration
117 ) where
149 ) where
118
150
119import Control.Category
151import Control.Category
120import Control.Monad
152import Control.Monad
121−import Control.Monad.Base
153+import Data.ByteString (ByteString)
122−import Control.Monad.Trans.Control
123−import Data.Monoid
154+import Data.Foldable (traverse_)
124−import Generics.SOP (K(..))
125import Data.Function ((&))
155import Data.Function ((&))
156+import Data.List ((\\))
126import Data.Text (Text)
157import Data.Text (Text)
158+import Data.Time (UTCTime)
127−import Prelude hiding (id, (.))
159+import Prelude hiding ((.), id)
160+import System.Environment
161+import UnliftIO (MonadIO (..))
162+
163+import qualified Data.Text.IO as Text (putStrLn)
164+import qualified Generics.SOP as SOP
165+import qualified GHC.Generics as GHC
128
166
129−import Squeal.PostgreSQL
167+import Squeal.PostgreSQL.Alias
168+import Squeal.PostgreSQL.Binary
169+import Squeal.PostgreSQL.Definition
170+import Squeal.PostgreSQL.Definition.Table
171+import Squeal.PostgreSQL.Definition.Table.Constraint
172+import Squeal.PostgreSQL.Expression.Comparison
173+import Squeal.PostgreSQL.Expression.Parameter
174+import Squeal.PostgreSQL.Expression.Time
175+import Squeal.PostgreSQL.Expression.Type
176+import Squeal.PostgreSQL.List
177+import Squeal.PostgreSQL.Manipulation
178+import Squeal.PostgreSQL.PQ
179+import Squeal.PostgreSQL.Query
180+import Squeal.PostgreSQL.Schema
181+import Squeal.PostgreSQL.Transaction
130
182
183+-- | A `Migration` is a named "isomorphism" over a given category.
131−-- | A `Migration` should contain an inverse pair of
184+-- It should contain an inverse pair of `up` and `down`
132−-- `up` and `down` instructions and a unique `name`.
185+-- instructions and a unique `name`.
133−data Migration io schema0 schema1 = Migration
186+data Migration p schemas0 schemas1 = Migration
134 { name :: Text -- ^ The `name` of a `Migration`.
187 { name :: Text -- ^ The `name` of a `Migration`.
135 -- Each `name` in a `Migration` should be unique.
188 -- Each `name` in a `Migration` should be unique.
136− , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.
189+ , up :: p schemas0 schemas1 -- ^ The `up` instruction of a `Migration`.
137− , down :: PQ schema1 schema0 io () -- ^ The `down` instruction of a `Migration`.
190+ , down :: p schemas1 schemas0 -- ^ The `down` instruction of a `Migration`.
191+ } deriving (GHC.Generic)
192+
193+{- |
194+A `Migratory` @p@ is a `Category` for which one can execute or rewind
195+a `Path` of `Migration`s over @p@. This includes the category of pure
196+SQL `Definition`s and the category of impure `Terminally` `PQ` `IO` actions.
197+-}
198+class Category p => Migratory p where
199+
200+ {- |
201+ Run a `Path` of `Migration`s.
202+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.
203+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;
204+ if not, `up` the `Migration` and insert its `name` in the `MigrationsTable`.
205+ -}
206+ migrateUp
207+ :: Path (Migration p) schemas0 schemas1
208+ -> PQ schemas0 schemas1 IO ()
209+
210+ {- |
211+ Rewind a `Path` of `Migration`s.
212+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.
213+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;
214+ if so, `down` the `Migration` and delete its `name` in the `MigrationsTable`.
215+ -}
216+ migrateDown
217+ :: Path (Migration p) schemas0 schemas1
218+ -> PQ schemas1 schemas0 IO ()
219+
220+instance Migratory Definition where
221+ migrateUp = migrateUp . cmap pureMigration
222+ migrateDown = migrateDown . cmap pureMigration
223+
224+{- | `Terminally` turns an indexed monad transformer and the monad it transforms
225+into a category by restricting the return type to @()@ and permuting the type variables.
226+This is similar to how applying a monad to @()@ yields a monoid.
227+Since a `Terminally` action has a trivial return value, the only reason
228+to run one is for the side effects, in particular database and other IO effects.
229+-}
230+newtype Terminally trans monad x0 x1 = Terminally
231+ { runTerminally :: trans x0 x1 monad () }
232+ deriving GHC.Generic
233+
234+instance
235+ ( IndexedMonadTransPQ trans
236+ , Monad monad
237+ , forall x0 x1. x0 ~ x1 => Monad (trans x0 x1 monad) )
238+ => Category (Terminally trans monad) where
239+ id = Terminally (return ())
240+ Terminally g . Terminally f = Terminally $ pqThen g f
241+
242+-- | `terminally` ignores the output of a computation, returning @()@ and
243+-- wrapping it up into a `Terminally`. You can lift an action in the base monad
244+-- by using @terminally . lift@.
245+terminally
246+ :: Functor (trans x0 x1 monad)
247+ => trans x0 x1 monad ignore
248+ -> Terminally trans monad x0 x1
249+terminally = Terminally . void
250+
251+-- | A `pureMigration` turns a `Migration` involving only pure SQL
252+-- `Definition`s into a `Migration` that may be combined with arbitrary `IO`.
253+pureMigration
254+ :: Migration Definition schemas0 schemas1
255+ -> Migration (Terminally PQ IO) schemas0 schemas1
256+pureMigration migration = Migration
257+ { name = name migration
258+ , up = terminally . define $ up migration
259+ , down = terminally . define $ down migration
138 }
260 }
139
261
140−-- | An `AlignedList` is a type-aligned list or free category.
262+instance Migratory (Terminally PQ IO) where
141−data AlignedList p x0 x1 where
142− Done :: AlignedList p x x
143− (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2
144−infixr 7 :>>
145−instance Category (AlignedList p) where
146− id = Done
147− (.) list = \case
148− Done -> list
149− step :>> steps -> step :>> (steps >>> list)
150−
151−-- | A `single` step.
152−single :: p x0 x1 -> AlignedList p x0 x1
153−single step = step :>> Done
154−
155−-- | Run `Migration`s by creating the `MigrationsTable`
156−-- if it does not exist and then in a transaction, for each each `Migration`
157−-- query to see if the `Migration` is executed. If not, then
158−-- execute the `Migration` and insert its row in the `MigrationsTable`.
159−migrateUp
160− :: MonadBaseControl IO io
161− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run
162− -> PQ
163− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
164− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
165− io ()
166−migrateUp migration =
167− define createMigrations
168− & pqBind okResult
169− & pqThen (transactionallySchema_ (upMigrations migration))
170− where
171
263
172− upMigrations
264+ migrateUp migration = unsafePQ . transactionally_ $ do
173− :: MonadBaseControl IO io
265+ define createMigrations
174− => AlignedList (Migration io) schema0 schema1
266+ upMigrations migration
175− -> PQ
267+
176− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
268+ where
177− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
269+
178− io ()
270+ upMigrations
271+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1
272+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
179− upMigrations = \case
273+ upMigrations = \case
180− Done -> return ()
274+ Done -> return ()
181− step :>> steps -> upMigration step & pqThen (upMigrations steps)
275+ step :>> steps -> upMigration step >> upMigrations steps
182−
276+
183− upMigration
277+ upMigration
184− :: MonadBase IO io
278+ :: Migration (Terminally PQ IO) schemas0 schemas1
185− => Migration io schema0 schema1 -> PQ
279+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
186− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
187− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
188− io ()
189− upMigration step =
280+ upMigration step = do
190− queryExecuted step
281+ executed <- queryExecuted step
191− & pqBind (\ executed ->
282+ unless (executed == 1) $ do
192− if executed == 1 -- up step has already been executed
283+ unsafePQ . runTerminally $ up step
193− then PQ (\ _ -> return (K ())) -- unsafely switch schemas
194− else
195− pqEmbed (up step) -- safely switch schemas
196− & pqThen (manipulateParams insertMigration (Only (name step)))
284+ manipulateParams_ insertMigration (Only (name step))
197− -- insert execution record
285+
198− & pqBind okResult)
199−
200− queryExecuted
286+ queryExecuted
201− :: MonadBase IO io
287+ :: Migration (Terminally PQ IO) schemas0 schemas1
202− => Migration io schema0 schema1 -> PQ
288+ -> PQ MigrationsSchemas MigrationsSchemas IO Row
203− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
204− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
205− io Row
206− queryExecuted step = do
289+ queryExecuted step = do
207− result <- runQueryParams selectMigration (Only (name step))
290+ result <- runQueryParams selectMigration (Only (name step))
208− okResult result
209− ntuples result
291+ ntuples result
210−
292+
211−-- | Rewind `Migration`s by creating the `MigrationsTable`
293+ migrateDown migrations = unsafePQ . transactionally_ $ do
212−-- if it does not exist and then in a transaction, for each each `Migration`
294+ define createMigrations
213−-- query to see if the `Migration` is executed. If it is, then
295+ downMigrations migrations
214−-- rewind the `Migration` and delete its row in the `MigrationsTable`.
296+
215−migrateDown
297+ where
216− :: MonadBaseControl IO io
298+
217− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind
299+ downMigrations
218− -> PQ
300+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1
219− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
301+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
220− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
302+ downMigrations = \case
221− io ()
303+ Done -> return ()
222−migrateDown migrations =
304+ step :>> steps -> downMigrations steps >> downMigration step
223− define createMigrations
224− & pqBind okResult
225− & pqThen (transactionallySchema_ (downMigrations migrations))
226− where
227
305
228− downMigrations
306+ downMigration
229− :: MonadBaseControl IO io
307+ :: Migration (Terminally PQ IO) schemas0 schemas1
230− => AlignedList (Migration io) schema0 schema1 -> PQ
308+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
231− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
232− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
233− io ()
234− downMigrations = \case
235− Done -> return ()
236− step :>> steps -> downMigrations steps & pqThen (downMigration step)
309+ downMigration step = do
237−
238− downMigration
239− :: MonadBase IO io
240− => Migration io schema0 schema1 -> PQ
241− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
242− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)
243− io ()
244− downMigration step =
245− queryExecuted step
310+ executed <- queryExecuted step
246− & pqBind (\ executed ->
311+ unless (executed == 0) $ do
247− if executed == 0 -- up step has not been executed
312+ unsafePQ . runTerminally $ down step
248− then PQ (\ _ -> return (K ())) -- unsafely switch schemas
249− else
250− pqEmbed (down step) -- safely switch schemas
251− & pqThen (manipulateParams deleteMigration (Only (name step)))
313+ manipulateParams_ deleteMigration (Only (name step))
252− -- delete execution record
314+
253− & pqBind okResult)
254−
255− queryExecuted
315+ queryExecuted
256− :: MonadBase IO io
316+ :: Migration (Terminally PQ IO) schemas0 schemas1
257− => Migration io schema0 schema1 -> PQ
317+ -> PQ MigrationsSchemas MigrationsSchemas IO Row
258− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
259− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)
260− io Row
261− queryExecuted step = do
318+ queryExecuted step = do
262− result <- runQueryParams selectMigration (Only (name step))
319+ result <- runQueryParams selectMigration (Only (name step))
263− okResult result
264− ntuples result
320+ ntuples result
265−
321+
266−okResult :: MonadBase IO io => K Result results -> PQ schema schema io ()
322+unsafePQ :: (Functor m) => PQ db0 db1 m x -> PQ db0' db1' m x
267−okResult result = do
323+unsafePQ (PQ pq) = PQ $ fmap (SOP.K . SOP.unK) . pq . SOP.K . SOP.unK
268− status <- resultStatus result
269− when (not (status `elem` [CommandOk, TuplesOk])) $ do
270− errorMessageMaybe <- resultErrorMessage result
271− case errorMessageMaybe of
272− Nothing -> error "migrateDown: unknown error"
273− Just msg -> error ("migrationDown: " <> show msg)
274
324
275-- | The `TableType` for a Squeal migration.
325-- | The `TableType` for a Squeal migration.
276type MigrationsTable =
326type MigrationsTable =
@@ -279,38 +329,120 @@ type MigrationsTable =
279 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz
329 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz
280 ]
330 ]
281
331
332+data MigrationRow =
333+ MigrationRow { migrationName :: Text
334+ , migrationTime :: UTCTime }
335+ deriving (GHC.Generic, Show)
336+
337+instance SOP.Generic MigrationRow
338+instance SOP.HasDatatypeInfo MigrationRow
339+
340+type MigrationsSchema = '["schema_migrations" ::: 'Table MigrationsTable]
341+type MigrationsSchemas = Public MigrationsSchema
342+
282-- | Creates a `MigrationsTable` if it does not already exist.
343-- | Creates a `MigrationsTable` if it does not already exist.
283−createMigrations
344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas
284− :: Has "schema_migrations" schema ('Table MigrationsTable)
285− => Definition schema schema
286createMigrations =
345createMigrations =
287 createTableIfNotExists #schema_migrations
346 createTableIfNotExists #schema_migrations
288− ( (text & notNullable) `As` #name :*
347+ ( (text & notNullable) `as` #name :*
289 (timestampWithTimeZone & notNullable & default_ currentTimestamp)
348 (timestampWithTimeZone & notNullable & default_ currentTimestamp)
290− `As` #executed_at :* Nil )
349+ `as` #executed_at )
291− ( unique (#name :* Nil) `As` #migrations_unique_name :* Nil )
350+ ( unique #name `as` #migrations_unique_name )
292−
351+
293−-- | Inserts a `Migration` into the `MigrationsTable`
352+-- | Inserts a `Migration` into the `MigrationsTable`, returning
294−insertMigration
353+-- the time at which it was inserted.
295− :: Has "schema_migrations" schema ('Table MigrationsTable)
354+insertMigration :: Manipulation_ MigrationsSchemas (Only Text) ()
296− => Manipulation schema '[ 'NotNull 'PGtext] '[]
297−insertMigration = insertRow_ #schema_migrations
355+insertMigration = insertInto_ #schema_migrations
298− ( Set (param @1) `As` #name :*
299− Default `As` #executed_at :* Nil )
356+ (Values_ (Set (param @1) `as` #name :* Default `as` #executed_at))
300−
357+
301−-- | Deletes a `Migration` from the `MigrationsTable`
358+-- | Deletes a `Migration` from the `MigrationsTable`, returning
359+-- the time at which it was inserted.
302−deleteMigration
360+deleteMigration :: Manipulation_ MigrationsSchemas (Only Text) ()
303− :: Has "schema_migrations" schema ('Table MigrationsTable)
304− => Manipulation schema '[ 'NotNull 'PGtext ] '[]
305deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)
361deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)
306
362
307-- | Selects a `Migration` from the `MigrationsTable`, returning
363-- | Selects a `Migration` from the `MigrationsTable`, returning
308−-- the time at which it was executed.
364+-- the time at which it was inserted.
309selectMigration
365selectMigration
310− :: Has "schema_migrations" schema ('Table MigrationsTable)
366+ :: Query_ MigrationsSchemas (Only Text) (Only UTCTime)
311− => Query schema '[ 'NotNull 'PGtext ]
312− '[ "executed_at" ::: 'NotNull 'PGtimestamptz ]
313−selectMigration = select
367+selectMigration = select_ (#executed_at `as` #fromOnly)
314− (#executed_at `As` #executed_at :* Nil)
315− ( from (table (#schema_migrations `As` #m))
368+ $ from (table (#schema_migrations))
316− & where_ (#name .== param @1))
369+ & where_ (#name .== param @1)
370+
371+selectMigrations :: Query_ MigrationsSchemas () MigrationRow
372+selectMigrations = select_
373+ (#name `as` #migrationName :* #executed_at `as` #migrationTime)
374+ (from (table #schema_migrations))
375+
376+data MigrateCommand
377+ = MigrateStatus
378+ | MigrateUp
379+ | MigrateDown deriving (GHC.Generic, Show)
380+
381+{- | `defaultMain` creates a simple executable
382+from a connection string and a list of `Migration`s. -}
383+defaultMain
384+ :: Migratory p
385+ => ByteString
386+ -- ^ connection string
387+ -> Path (Migration p) db0 db1
388+ -- ^ migrations
389+ -> IO ()
390+defaultMain connectTo migrations = do
391+ command <- readCommandFromArgs
392+ maybe (pure ()) performCommand command
393+
394+ where
395+
396+ performCommand :: MigrateCommand -> IO ()
397+ performCommand = \case
398+ MigrateStatus -> withConnection connectTo $
399+ suppressNotices >> migrateStatus
400+ MigrateUp -> withConnection connectTo $
401+ suppressNotices & pqThen (migrateUp migrations) & pqThen migrateStatus
402+ MigrateDown -> withConnection connectTo $
403+ suppressNotices & pqThen (migrateDown migrations) & pqThen migrateStatus
404+
405+ migrateStatus :: PQ schema schema IO ()
406+ migrateStatus = unsafePQ $ do
407+ runNames <- getRunMigrationNames
408+ let names = ctoList name migrations
409+ unrunNames = names \\ runNames
410+ liftIO $ displayRunned runNames >> displayUnrunned unrunNames
411+
412+ suppressNotices :: PQ schema schema IO ()
413+ suppressNotices = manipulate_ $
414+ UnsafeManipulation "SET client_min_messages TO WARNING;"
415+
416+ readCommandFromArgs :: IO (Maybe MigrateCommand)
417+ readCommandFromArgs = getArgs >>= \case
418+ ["migrate"] -> pure . Just $ MigrateUp
419+ ["rollback"] -> pure . Just $ MigrateDown
420+ ["status"] -> pure . Just $ MigrateStatus
421+ args -> displayUsage args >> pure Nothing
422+
423+ displayUsage :: [String] -> IO ()
424+ displayUsage args = do
425+ putStrLn $ "Invalid command: \"" <> unwords args <> "\". Use:"
426+ putStrLn "migrate to run all available migrations"
427+ putStrLn "rollback to rollback all available migrations"
428+ putStrLn "status to display migrations run and migrations left to run"
429+
430+ getRunMigrationNames :: (MonadIO m) => PQ db0 db0 m [Text]
431+ getRunMigrationNames =
432+ fmap migrationName <$> (unsafePQ (define createMigrations & pqThen (runQuery selectMigrations)) >>= getRows)
433+
434+ displayListOfNames :: [Text] -> IO ()
435+ displayListOfNames [] = Text.putStrLn " None"
436+ displayListOfNames xs =
437+ let singleName n = Text.putStrLn $ " - " <> n
438+ in traverse_ singleName xs
439+
440+ displayUnrunned :: [Text] -> IO ()
441+ displayUnrunned unrunned =
442+ Text.putStrLn "Migrations left to run:"
443+ >> displayListOfNames unrunned
444+
445+ displayRunned :: [Text] -> IO ()
446+ displayRunned runned =
447+ Text.putStrLn "Migrations already run:"
448+ >> displayListOfNames runned
squeal-postgresql/src/Squeal/PostgreSQL/PG.hsnew file+388
@@ -0,0 +1,388 @@
1+{-|
2+Module: Squeal.PostgreSQL.PG
3+Description: Embedding of Haskell types into Postgres's type system
4+Copyright: (c) Eitan Chatav, 2010
5+Maintainer: eitan@morphism.tech
6+Stability: experimental
7+
8+`Squeal.PostgreSQL.PG` provides type families for turning Haskell
9+`Type`s into corresponding Postgres types.
10+-}
11+{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , DeriveAnyClass
14+ , DeriveFoldable
15+ , DeriveFunctor
16+ , DeriveGeneric
17+ , DeriveTraversable
18+ , DerivingStrategies
19+ , DefaultSignatures
20+ , FlexibleContexts
21+ , FlexibleInstances
22+ , FunctionalDependencies
23+ , GADTs
24+ , LambdaCase
25+ , MultiParamTypeClasses
26+ , OverloadedStrings
27+ , ScopedTypeVariables
28+ , TypeApplications
29+ , TypeFamilies
30+ , TypeInType
31+ , TypeOperators
32+ , UndecidableInstances
33+ , UndecidableSuperClasses
34+#-}
35+
36+module Squeal.PostgreSQL.PG
37+ ( -- * PG embeddings
38+ PG
39+ , NullPG
40+ , TuplePG
41+ , RowPG
42+ -- * Storage newtypes
43+ , Money (..)
44+ , Json (..)
45+ , Jsonb (..)
46+ , Composite (..)
47+ , Enumerated (..)
48+ , VarArray (..)
49+ , FixArray (..)
50+ , LibPQ.Oid (..)
51+ -- * Type families
52+ , LabelsPG
53+ , DimPG
54+ , FixPG
55+ , TupleOf
56+ , TupleCodeOf
57+ , RowOf
58+ , ConstructorsOf
59+ , ConstructorNameOf
60+ , ConstructorNamesOf
61+ ) where
62+
63+import Data.Aeson (Value)
64+import Data.Kind (Type)
65+import Data.Int (Int16, Int32, Int64)
66+import Data.Scientific (Scientific)
67+import Data.Time (Day, DiffTime, LocalTime, TimeOfDay, TimeZone, UTCTime)
68+import Data.Vector (Vector)
69+import Data.UUID.Types (UUID)
70+import GHC.TypeLits
71+import Network.IP.Addr (NetAddr, IP)
72+
73+import qualified Data.ByteString.Lazy as Lazy (ByteString)
74+import qualified Data.ByteString as Strict (ByteString)
75+import qualified Data.Text.Lazy as Lazy (Text)
76+import qualified Data.Text as Strict (Text)
77+import qualified Database.PostgreSQL.LibPQ as LibPQ
78+import qualified GHC.Generics as GHC
79+import qualified Generics.SOP as SOP
80+import qualified Generics.SOP.Record as SOP
81+import qualified Generics.SOP.Type.Metadata as Type
82+
83+import Squeal.PostgreSQL.Alias
84+import Squeal.PostgreSQL.Schema
85+
86+-- $setup
87+-- >>> import Squeal.PostgreSQL
88+-- >>> import Data.Text (Text)
89+
90+{- | The `PG` type family embeds a subset of Haskell types
91+as Postgres types. As an open type family, `PG` is extensible.
92+
93+>>> :kind! PG LocalTime
94+PG LocalTime :: PGType
95+= 'PGtimestamp
96+
97+>>> newtype MyDouble = My Double
98+>>> :set -XTypeFamilies
99+>>> type instance PG MyDouble = 'PGfloat8
100+-}
101+type family PG (hask :: Type) :: PGType
102+-- | `PGbool`
103+type instance PG Bool = 'PGbool
104+-- | `PGint2`
105+type instance PG Int16 = 'PGint2
106+-- | `PGint4`
107+type instance PG Int32 = 'PGint4
108+-- | `PGint8`
109+type instance PG Int64 = 'PGint8
110+-- | `PGint2`
111+type instance PG LibPQ.Oid = 'PGoid
112+-- | `PGnumeric`
113+type instance PG Scientific = 'PGnumeric
114+-- | `PGfloat4`
115+type instance PG Float = 'PGfloat4
116+-- | `PGfloat8`
117+type instance PG Double = 'PGfloat8
118+-- | `PGchar` @1@
119+type instance PG Char = 'PGchar 1
120+-- | `PGtext`
121+type instance PG Strict.Text = 'PGtext
122+-- | `PGtext`
123+type instance PG Lazy.Text = 'PGtext
124+-- | `PGtext`
125+type instance PG String = 'PGtext
126+-- | `PGbytea`
127+type instance PG Strict.ByteString = 'PGbytea
128+-- | `PGbytea`
129+type instance PG Lazy.ByteString = 'PGbytea
130+-- | `PGtimestamp`
131+type instance PG LocalTime = 'PGtimestamp
132+-- | `PGtimestamptz`
133+type instance PG UTCTime = 'PGtimestamptz
134+-- | `PGdate`
135+type instance PG Day = 'PGdate
136+-- | `PGtime`
137+type instance PG TimeOfDay = 'PGtime
138+-- | `PGtimetz`
139+type instance PG (TimeOfDay, TimeZone) = 'PGtimetz
140+-- | `PGinterval`
141+type instance PG DiffTime = 'PGinterval
142+-- | `PGuuid`
143+type instance PG UUID = 'PGuuid
144+-- | `PGinet`
145+type instance PG (NetAddr IP) = 'PGinet
146+-- | `PGjson`
147+type instance PG Value = 'PGjson
148+
149+{-| The `LabelsPG` type family calculates the constructors of a
150+Haskell enum type.
151+
152+>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
153+>>> instance SOP.Generic Schwarma
154+>>> instance SOP.HasDatatypeInfo Schwarma
155+>>> :kind! LabelsPG Schwarma
156+LabelsPG Schwarma :: [Type.ConstructorName]
157+= '["Beef", "Lamb", "Chicken"]
158+-}
159+type family LabelsPG (hask :: Type) :: [Type.ConstructorName] where
160+ LabelsPG hask =
161+ ConstructorNamesOf (ConstructorsOf (SOP.DatatypeInfoOf hask))
162+
163+{- |
164+`RowPG` turns a Haskell `Type` into a `RowType`.
165+
166+`RowPG` may be applied to normal Haskell record types provided they
167+have `SOP.Generic` and `SOP.HasDatatypeInfo` instances;
168+
169+>>> data Person = Person { name :: Strict.Text, age :: Int32 } deriving GHC.Generic
170+>>> instance SOP.Generic Person
171+>>> instance SOP.HasDatatypeInfo Person
172+>>> :kind! RowPG Person
173+RowPG Person :: [(Symbol, NullityType)]
174+= '["name" ::: 'NotNull 'PGtext, "age" ::: 'NotNull 'PGint4]
175+-}
176+type family RowPG (hask :: Type) :: RowType where
177+ RowPG hask = RowOf (SOP.RecordCodeOf hask)
178+
179+-- | `RowOf` applies `NullPG` to the fields of a list.
180+type family RowOf (record :: [(Symbol, Type)]) :: RowType where
181+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': col4 ::: ty4 ': record) =
182+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': col4 ::: NullPG ty4 ': RowOf record
183+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': record) =
184+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': RowOf record
185+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': record) =
186+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': RowOf record
187+ RowOf (col ::: ty ': col1 ::: ty1 ': record) =
188+ col ::: NullPG ty ': col1::: NullPG ty1 ': RowOf record
189+ RowOf (col ::: ty ': record) = col ::: NullPG ty ': RowOf record
190+ RowOf '[] = '[]
191+
192+{- | `NullPG` turns a Haskell type into a `NullityType`.
193+
194+>>> :kind! NullPG Double
195+NullPG Double :: NullityType
196+= 'NotNull 'PGfloat8
197+>>> :kind! NullPG (Maybe Double)
198+NullPG (Maybe Double) :: NullityType
199+= 'Null 'PGfloat8
200+-}
201+type family NullPG (hask :: Type) :: NullityType where
202+ NullPG (Maybe hask) = 'Null (PG hask)
203+ NullPG hask = 'NotNull (PG hask)
204+
205+{- | `TuplePG` turns a Haskell tuple type (including record types) into
206+the corresponding list of `NullityType`s.
207+
208+>>> :kind! TuplePG (Double, Maybe Char)
209+TuplePG (Double, Maybe Char) :: [NullityType]
210+= '[ 'NotNull 'PGfloat8, 'Null ('PGchar 1)]
211+-}
212+type family TuplePG (hask :: Type) :: [NullityType] where
213+ TuplePG hask = TupleOf (TupleCodeOf hask (SOP.Code hask))
214+
215+-- | `TupleOf` turns a list of Haskell `Type`s into a list of `NullityType`s.
216+type family TupleOf (tuple :: [Type]) :: [NullityType] where
217+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': hask5 ': tuple) =
218+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': NullPG hask5 ': TupleOf tuple
219+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': tuple) =
220+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': TupleOf tuple
221+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': tuple) =
222+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': TupleOf tuple
223+ TupleOf (hask ': hask1 ': hask2 ': tuple) =
224+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': TupleOf tuple
225+ TupleOf (hask ': hask1 ': tuple) = NullPG hask ': NullPG hask1 ': TupleOf tuple
226+ TupleOf (hask ': tuple) = NullPG hask ': TupleOf tuple
227+ TupleOf '[] = '[]
228+
229+-- | `TupleCodeOf` takes the `SOP.Code` of a haskell `Type`
230+-- and if it's a simple product returns it, otherwise giving a `TypeError`.
231+type family TupleCodeOf (hask :: Type) (code :: [[Type]]) :: [Type] where
232+ TupleCodeOf hask '[tuple] = tuple
233+ TupleCodeOf hask '[] =
234+ TypeError
235+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."
236+ ':$$: 'Text "It is a void type with no constructors."
237+ )
238+ TupleCodeOf hask (_ ': _ ': _) =
239+ TypeError
240+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."
241+ ':$$: 'Text "It is a sum type with more than one constructor."
242+ )
243+
244+-- | Calculates constructors of a datatype.
245+type family ConstructorsOf (datatype :: Type.DatatypeInfo)
246+ :: [Type.ConstructorInfo] where
247+ ConstructorsOf ('Type.ADT _module _datatype constructors) =
248+ constructors
249+ ConstructorsOf ('Type.Newtype _module _datatype constructor) =
250+ '[constructor]
251+
252+-- | Calculates the name of a nullary constructor, otherwise
253+-- generates a type error.
254+type family ConstructorNameOf (constructor :: Type.ConstructorInfo)
255+ :: Type.ConstructorName where
256+ ConstructorNameOf ('Type.Constructor name) = name
257+ ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError
258+ ('Text "ConstructorNameOf error: non-nullary constructor "
259+ ':<>: 'Text name)
260+ ConstructorNameOf ('Type.Record name _fields) = TypeError
261+ ('Text "ConstructorNameOf error: non-nullary constructor "
262+ ':<>: 'Text name)
263+
264+-- | Calculate the names of nullary constructors.
265+type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])
266+ :: [Type.ConstructorName] where
267+ ConstructorNamesOf '[] = '[]
268+ ConstructorNamesOf (constructor ': constructors) =
269+ ConstructorNameOf constructor ': ConstructorNamesOf constructors
270+
271+-- | `DimPG` turns Haskell nested homogeneous tuples into a list of lengths.
272+type family DimPG (hask :: Type) :: [Nat] where
273+ DimPG (x,x) = 2 ': DimPG x
274+ DimPG (x,x,x) = 3 ': DimPG x
275+ DimPG (x,x,x,x) = 4 ': DimPG x
276+ DimPG (x,x,x,x,x) = 5 ': DimPG x
277+ DimPG (x,x,x,x,x,x) = 6 ': DimPG x
278+ DimPG (x,x,x,x,x,x,x) = 7 ': DimPG x
279+ DimPG (x,x,x,x,x,x,x,x) = 8 ': DimPG x
280+ DimPG (x,x,x,x,x,x,x,x,x) = 9 ': DimPG x
281+ DimPG (x,x,x,x,x,x,x,x,x,x) = 10 ': DimPG x
282+ DimPG x = '[]
283+
284+-- | `FixPG` extracts `NullPG` of the base type of nested homogeneous tuples.
285+type family FixPG (hask :: Type) :: NullityType where
286+ FixPG (x,x) = FixPG x
287+ FixPG (x,x,x) = FixPG x
288+ FixPG (x,x,x,x) = FixPG x
289+ FixPG (x,x,x,x,x) = FixPG x
290+ FixPG (x,x,x,x,x,x) = FixPG x
291+ FixPG (x,x,x,x,x,x,x) = FixPG x
292+ FixPG (x,x,x,x,x,x,x,x) = FixPG x
293+ FixPG (x,x,x,x,x,x,x,x,x) = FixPG x
294+ FixPG (x,x,x,x,x,x,x,x,x,x) = FixPG x
295+ FixPG (x,x,x,x,x,x,x,x,x,x,x) = FixPG x
296+ FixPG x = NullPG x
297+
298+{- | The `Money` newtype stores a monetary value in terms
299+of the number of cents, i.e. @$2,000.20@ would be expressed as
300+@Money { cents = 200020 }@.
301+
302+>>> import Control.Monad (void)
303+>>> import Control.Monad.IO.Class (liftIO)
304+>>> import Squeal.PostgreSQL
305+>>> :{
306+let
307+ roundTrip :: Query_ (Public '[]) (Only Money) (Only Money)
308+ roundTrip = values_ $ parameter @1 money `as` #fromOnly
309+:}
310+
311+>>> let input = Only (Money 20020)
312+
313+>>> :{
314+withConnection "host=localhost port=5432 dbname=exampledb" $ do
315+ result <- runQueryParams roundTrip input
316+ Just output <- firstRow result
317+ liftIO . print $ input == output
318+:}
319+True
320+-}
321+newtype Money = Money { cents :: Int64 }
322+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)
323+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)
324+-- | `PGmoney`
325+type instance PG Money = 'PGmoney
326+
327+{- | The `Json` newtype is an indication that the Haskell
328+type it's applied to should be stored as a `PGjson`.
329+-}
330+newtype Json hask = Json {getJson :: hask}
331+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)
332+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)
333+-- | `PGjson`
334+type instance PG (Json hask) = 'PGjson
335+
336+{- | The `Jsonb` newtype is an indication that the Haskell
337+type it's applied to should be stored as a `PGjsonb`.
338+-}
339+newtype Jsonb hask = Jsonb {getJsonb :: hask}
340+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)
341+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)
342+-- | `PGjsonb`
343+type instance PG (Jsonb hask) = 'PGjsonb
344+
345+{- | The `Composite` newtype is an indication that the Haskell
346+type it's applied to should be stored as a `PGcomposite`.
347+-}
348+newtype Composite record = Composite {getComposite :: record}
349+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)
350+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)
351+-- | `PGcomposite` @(@`RowPG` @hask)@
352+type instance PG (Composite hask) = 'PGcomposite (RowPG hask)
353+
354+{- | The `Enumerated` newtype is an indication that the Haskell
355+type it's applied to should be stored as a `PGenum`.
356+-}
357+newtype Enumerated enum = Enumerated {getEnumerated :: enum}
358+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)
359+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)
360+-- | `PGenum` @(@`LabelsPG` @hask)@
361+type instance PG (Enumerated hask) = 'PGenum (LabelsPG hask)
362+
363+{- | The `VarArray` newtype is an indication that the Haskell
364+type it's applied to should be stored as a `PGvararray`.
365+
366+>>> :kind! PG (VarArray (Vector Double))
367+PG (VarArray (Vector Double)) :: PGType
368+= 'PGvararray ('NotNull 'PGfloat8)
369+-}
370+newtype VarArray arr = VarArray {getVarArray :: arr}
371+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)
372+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)
373+-- | `PGvararray` @(@`NullPG` @hask)@
374+type instance PG (VarArray (Vector hask)) = 'PGvararray (NullPG hask)
375+type instance PG (VarArray [hask]) = 'PGvararray (NullPG hask)
376+
377+{- | The `FixArray` newtype is an indication that the Haskell
378+type it's applied to should be stored as a `PGfixarray`.
379+
380+>>> :kind! PG (FixArray ((Double, Double), (Double, Double)))
381+PG (FixArray ((Double, Double), (Double, Double))) :: PGType
382+= 'PGfixarray '[2, 2] ('NotNull 'PGfloat8)
383+-}
384+newtype FixArray arr = FixArray {getFixArray :: arr}
385+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)
386+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)
387+-- | `PGfixarray` @(@`DimPG` @hask) (@`FixPG` @hask)@
388+type instance PG (FixArray hask) = 'PGfixarray (DimPG hask) (FixPG hask)
squeal-postgresql/src/Squeal/PostgreSQL/PQ.hs+312−211
@@ -6,12 +6,12 @@ Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
8This module is where Squeal commands actually get executed by
8This module is where Squeal commands actually get executed by
9−`LibPQ`. It containts two typeclasses, `IndexedMonadTransPQ` for executing
9+`Database.PostgreSQL.LibPQ`. It containts two typeclasses, `IndexedMonadTransPQ` for executing
10a `Definition` and `MonadPQ` for executing a `Manipulation` or `Query`,
10a `Definition` and `MonadPQ` for executing a `Manipulation` or `Query`,
11and a `PQ` type with instances for them.
11and a `PQ` type with instances for them.
12
12
13Using Squeal in your application will come down to defining
13Using Squeal in your application will come down to defining
14−the @schema@ of your database and including @PQ schema schema@ in your
14+the @schemas@ of your database and including @PQ schemas schemas@ in your
15application's monad transformer stack, giving it an instance of `MonadPQ`.
15application's monad transformer stack, giving it an instance of `MonadPQ`.
16
16
17This module also provides functions for retrieving rows from the `LibPQ.Result`
17This module also provides functions for retrieving rows from the `LibPQ.Result`
@@ -24,6 +24,7 @@ of executing Squeal commands.
24 , FunctionalDependencies
24 , FunctionalDependencies
25 , FlexibleContexts
25 , FlexibleContexts
26 , FlexibleInstances
26 , FlexibleInstances
27+ , InstanceSigs
27 , OverloadedStrings
28 , OverloadedStrings
28 , RankNTypes
29 , RankNTypes
29 , ScopedTypeVariables
30 , ScopedTypeVariables
@@ -48,9 +49,7 @@ module Squeal.PostgreSQL.PQ
48 , evalPQ
49 , evalPQ
49 , IndexedMonadTransPQ (..)
50 , IndexedMonadTransPQ (..)
50 , MonadPQ (..)
51 , MonadPQ (..)
51− , PQRun
52+ -- * Results
52− , pqliftWith
53− -- * Result
54 , LibPQ.Result
53 , LibPQ.Result
55 , LibPQ.Row
54 , LibPQ.Row
56 , ntuples
55 , ntuples
@@ -62,22 +61,33 @@ module Squeal.PostgreSQL.PQ
62 , LibPQ.ExecStatus (..)
61 , LibPQ.ExecStatus (..)
63 , resultStatus
62 , resultStatus
64 , resultErrorMessage
63 , resultErrorMessage
64+ , resultErrorCode
65+ -- * Exceptions
66+ , SquealException (..)
67+ , PQState (..)
68+ , okResult
69+ , catchSqueal
70+ , handleSqueal
71+ , trySqueal
65 ) where
72 ) where
66
73
67−import Control.Exception.Lifted
74+import Control.Exception (Exception, throw)
68−import Control.Monad.Base
69import Control.Monad.Except
75import Control.Monad.Except
70import Control.Monad.Morph
76import Control.Monad.Morph
71−import Control.Monad.Trans.Control
77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)
72import Data.ByteString (ByteString)
78import Data.ByteString (ByteString)
73import Data.Foldable
79import Data.Foldable
74import Data.Function ((&))
80import Data.Function ((&))
81+import Data.Functor ((<&>))
75import Data.Kind
82import Data.Kind
76−import Data.Monoid
83+import Data.Text (pack, Text)
77import Data.Traversable
84import Data.Traversable
78import Generics.SOP
85import Generics.SOP
86+import PostgreSQL.Binary.Encoding (encodingBytes)
79
87
88+import qualified Control.Monad.Fail as Fail
80import qualified Database.PostgreSQL.LibPQ as LibPQ
89import qualified Database.PostgreSQL.LibPQ as LibPQ
90+import qualified PostgreSQL.Binary.Encoding as Encoding
81
91
82import Squeal.PostgreSQL.Binary
92import Squeal.PostgreSQL.Binary
83import Squeal.PostgreSQL.Definition
93import Squeal.PostgreSQL.Definition
@@ -90,7 +100,6 @@ import Control.Monad.Trans.Identity
90import Control.Monad.Trans.Reader
100import Control.Monad.Trans.Reader
91import Control.Monad.Trans.Maybe
101import Control.Monad.Trans.Maybe
92import Control.Monad.Trans.Cont
102import Control.Monad.Trans.Cont
93−import Control.Monad.Trans.List
94
103
95import qualified Control.Monad.Trans.State.Lazy as Lazy
104import qualified Control.Monad.Trans.State.Lazy as Lazy
96import qualified Control.Monad.Trans.State.Strict as Strict
105import qualified Control.Monad.Trans.State.Strict as Strict
@@ -99,6 +108,9 @@ import qualified Control.Monad.Trans.Writer.Strict as Strict
99import qualified Control.Monad.Trans.RWS.Lazy as Lazy
108import qualified Control.Monad.Trans.RWS.Lazy as Lazy
100import qualified Control.Monad.Trans.RWS.Strict as Strict
109import qualified Control.Monad.Trans.RWS.Strict as Strict
101
110
111+-- $setup
112+-- >>> import Squeal.PostgreSQL
113+
102{- | Makes a new connection to the database server.
114{- | Makes a new connection to the database server.
103
115
104This function opens a new database connection using the parameters taken
116This function opens a new database connection using the parameters taken
@@ -125,22 +137,22 @@ Note that, for now, squeal doesn't offer any protection from connecting
125with the wrong schema!
137with the wrong schema!
126-}
138-}
127connectdb
139connectdb
128− :: forall schema io
140+ :: forall schemas io
129− . MonadBase IO io
141+ . MonadIO io
130 => ByteString -- ^ conninfo
142 => ByteString -- ^ conninfo
131− -> io (K LibPQ.Connection schema)
143+ -> io (K LibPQ.Connection schemas)
132−connectdb = fmap K . liftBase . LibPQ.connectdb
144+connectdb = fmap K . liftIO . LibPQ.connectdb
133
145
134-- | Closes the connection to the server.
146-- | Closes the connection to the server.
135−finish :: MonadBase IO io => K LibPQ.Connection schema -> io ()
147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()
136−finish = liftBase . LibPQ.finish . unK
148+finish = liftIO . LibPQ.finish . unK
137
149
138-- | Do `connectdb` and `finish` before and after a computation.
150-- | Do `connectdb` and `finish` before and after a computation.
139withConnection
151withConnection
140− :: forall schema0 schema1 io x
152+ :: forall schemas0 schemas1 io x
141− . MonadBaseControl IO io
153+ . MonadUnliftIO io
142 => ByteString
154 => ByteString
143− -> PQ schema0 schema1 io x
155+ -> PQ schemas0 schemas1 io x
144 -> io x
156 -> io x
145withConnection connString action = do
157withConnection connString action = do
146 K x <- bracket (connectdb connString) finish (unPQ action)
158 K x <- bracket (connectdb connString) finish (unPQ action)
@@ -148,47 +160,47 @@ withConnection connString action = do
148
160
149-- | Safely `lowerConnection` to a smaller schema.
161-- | Safely `lowerConnection` to a smaller schema.
150lowerConnection
162lowerConnection
151− :: K LibPQ.Connection (table ': schema)
163+ :: K LibPQ.Connection (schema ': schemas)
152− -> K LibPQ.Connection schema
164+ -> K LibPQ.Connection schemas
153lowerConnection (K conn) = K conn
165lowerConnection (K conn) = K conn
154
166
155-- | We keep track of the schema via an Atkey indexed state monad transformer,
167-- | We keep track of the schema via an Atkey indexed state monad transformer,
156-- `PQ`.
168-- `PQ`.
157newtype PQ
169newtype PQ
158− (schema0 :: SchemaType)
170+ (schemas0 :: SchemasType)
159− (schema1 :: SchemaType)
171+ (schemas1 :: SchemasType)
160 (m :: Type -> Type)
172 (m :: Type -> Type)
161 (x :: Type) =
173 (x :: Type) =
162− PQ { unPQ :: K LibPQ.Connection schema0 -> m (K x schema1) }
174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }
163
175
164−instance Monad m => Functor (PQ schema0 schema1 m) where
176+instance Monad m => Functor (PQ schemas0 schemas1 m) where
165 fmap f (PQ pq) = PQ $ \ conn -> do
177 fmap f (PQ pq) = PQ $ \ conn -> do
166 K x <- pq conn
178 K x <- pq conn
167 return $ K (f x)
179 return $ K (f x)
168
180
169−-- | Run a `PQ` and keep the result and the `Connection`.
181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.
170runPQ
182runPQ
171 :: Functor m
183 :: Functor m
172− => PQ schema0 schema1 m x
184+ => PQ schemas0 schemas1 m x
173− -> K LibPQ.Connection schema0
185+ -> K LibPQ.Connection schemas0
174− -> m (x, K LibPQ.Connection schema1)
186+ -> m (x, K LibPQ.Connection schemas1)
175runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn
187runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn
176 -- K x <- pq conn
188 -- K x <- pq conn
177 -- return (x, K (unK conn))
189 -- return (x, K (unK conn))
178
190
179−-- | Execute a `PQ` and discard the result but keep the `Connection`.
191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.
180execPQ
192execPQ
181 :: Functor m
193 :: Functor m
182− => PQ schema0 schema1 m x
194+ => PQ schemas0 schemas1 m x
183− -> K LibPQ.Connection schema0
195+ -> K LibPQ.Connection schemas0
184− -> m (K LibPQ.Connection schema1)
196+ -> m (K LibPQ.Connection schemas1)
185execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn
197execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn
186
198
187−-- | Evaluate a `PQ` and discard the `Connection` but keep the result.
199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.
188evalPQ
200evalPQ
189 :: Functor m
201 :: Functor m
190− => PQ schema0 schema1 m x
202+ => PQ schemas0 schemas1 m x
191− -> K LibPQ.Connection schema0
203+ -> K LibPQ.Connection schemas0
192 -> m x
204 -> m x
193evalPQ (PQ pq) conn = unK <$> pq conn
205evalPQ (PQ pq) conn = unK <$> pq conn
194
206
@@ -196,60 +208,56 @@ evalPQ (PQ pq) conn = unK <$> pq conn
196-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).
208-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).
197-- An indexed monad transformer transforms a `Monad` into an indexed monad.
209-- An indexed monad transformer transforms a `Monad` into an indexed monad.
198-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that
210-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that
199−-- support running `Definition`s using `define` and embedding a computation
211+-- support running `Definition`s using `define`.
200−-- in a larger schema using `pqEmbed`.
201class IndexedMonadTransPQ pq where
212class IndexedMonadTransPQ pq where
202
213
203 -- | indexed analog of `<*>`
214 -- | indexed analog of `<*>`
204 pqAp
215 pqAp
205 :: Monad m
216 :: Monad m
206− => pq schema0 schema1 m (x -> y)
217+ => pq schemas0 schemas1 m (x -> y)
207− -> pq schema1 schema2 m x
218+ -> pq schemas1 schemas2 m x
208− -> pq schema0 schema2 m y
219+ -> pq schemas0 schemas2 m y
209
220
210 -- | indexed analog of `join`
221 -- | indexed analog of `join`
211 pqJoin
222 pqJoin
212 :: Monad m
223 :: Monad m
213− => pq schema0 schema1 m (pq schema1 schema2 m y)
224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)
214− -> pq schema0 schema2 m y
225+ -> pq schemas0 schemas2 m y
215 pqJoin pq = pq & pqBind id
226 pqJoin pq = pq & pqBind id
216
227
217 -- | indexed analog of `=<<`
228 -- | indexed analog of `=<<`
218 pqBind
229 pqBind
219 :: Monad m
230 :: Monad m
220− => (x -> pq schema1 schema2 m y)
231+ => (x -> pq schemas1 schemas2 m y)
221− -> pq schema0 schema1 m x
232+ -> pq schemas0 schemas1 m x
222− -> pq schema0 schema2 m y
233+ -> pq schemas0 schemas2 m y
223
234
224 -- | indexed analog of flipped `>>`
235 -- | indexed analog of flipped `>>`
225 pqThen
236 pqThen
226 :: Monad m
237 :: Monad m
227− => pq schema1 schema2 m y
238+ => pq schemas1 schemas2 m y
228− -> pq schema0 schema1 m x
239+ -> pq schemas0 schemas1 m x
229− -> pq schema0 schema2 m y
240+ -> pq schemas0 schemas2 m y
230 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)
241 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)
231
242
232 -- | indexed analog of `<=<`
243 -- | indexed analog of `<=<`
233 pqAndThen
244 pqAndThen
234 :: Monad m
245 :: Monad m
235− => (y -> pq schema1 schema2 m z)
246+ => (y -> pq schemas1 schemas2 m z)
236− -> (x -> pq schema0 schema1 m y)
247+ -> (x -> pq schemas0 schemas1 m y)
237− -> x -> pq schema0 schema2 m z
248+ -> x -> pq schemas0 schemas2 m z
238 pqAndThen g f x = pqBind g (f x)
249 pqAndThen g f x = pqBind g (f x)
239
250
240− -- | Safely embed a computation in a larger schema.
241− pqEmbed
242− :: Monad m
243− => pq schema0 schema1 m x
244− -> pq (table ': schema0) (table : schema1) m x
245−
246− -- | Run a `Definition` with `LibPQ.exec`, we expect that libpq obeys the law
251+ -- | Run a `Definition` with `LibPQ.exec`.
252+ --
253+ -- It should be functorial in effect.
247 --
254 --
255+ -- @define id = return ()@
248− -- @define statement1 & pqThen (define statement2) = define (statement1 >>> statement2)@
256+ -- @define (statement1 >>> statement2) = define statement1 & pqThen (define statement2)@
249 define
257 define
250− :: MonadBase IO io
258+ :: MonadIO io
251− => Definition schema0 schema1
259+ => Definition schemas0 schemas1
252− -> pq schema0 schema1 io (K LibPQ.Result '[])
260+ -> pq schemas0 schemas1 io ()
253
261
254instance IndexedMonadTransPQ PQ where
262instance IndexedMonadTransPQ PQ where
255
263
@@ -262,26 +270,26 @@ instance IndexedMonadTransPQ PQ where
262 K x' <- x conn
270 K x' <- x conn
263 unPQ (f x') (K (unK conn))
271 unPQ (f x') (K (unK conn))
264
272
265− pqEmbed (PQ pq) = PQ $ \ (K conn) -> do
266− K x <- pq (K conn)
267− return $ K x
268−
269 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do
273 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do
270− resultMaybe <- liftBase $ LibPQ.exec conn q
274+ resultMaybe <- liftIO $ LibPQ.exec conn q
271 case resultMaybe of
275 case resultMaybe of
272− Nothing -> error
276+ Nothing -> throw $ ResultException
273 "define: LibPQ.exec returned no results"
277 "define: LibPQ.exec returned no results"
274− Just result -> return $ K (K result)
278+ Just result -> K <$> okResult_ result
275
279
276−{- | `MonadPQ` is an `mtl` style constraint, similar to
280+{- | `MonadPQ` is an @mtl@ style constraint, similar to
277−`Control.Monad.State.Class.MonadState`, for using `LibPQ` to
281+`Control.Monad.State.Class.MonadState`, for using `Database.PostgreSQL.LibPQ` to
278
282
279* `manipulateParams` runs a `Manipulation` with params from a type
283* `manipulateParams` runs a `Manipulation` with params from a type
280 with a `ToParams` constraint. It calls `LibPQ.execParams` and
284 with a `ToParams` constraint. It calls `LibPQ.execParams` and
281 doesn't afraid of anything.
285 doesn't afraid of anything.
282
286
287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.
288+
283* `manipulate` is like `manipulateParams` for a parameter-free statement.
289* `manipulate` is like `manipulateParams` for a parameter-free statement.
284
290
291+* `manipulate_` is like `manipulate` for a returning-free statement.
292+
285* `runQueryParams` is like `manipulateParams` for query statements.
293* `runQueryParams` is like `manipulateParams` for query statements.
286
294
287* `runQuery` is like `runQueryParams` for a parameter-free statement.
295* `runQuery` is like `runQueryParams` for a parameter-free statement.
@@ -295,11 +303,11 @@ instance IndexedMonadTransPQ PQ where
295* `forPrepared` is a flipped `traversePrepared`
303* `forPrepared` is a flipped `traversePrepared`
296
304
297* `traversePrepared_` is like `traversePrepared` but works on `Foldable`
305* `traversePrepared_` is like `traversePrepared` but works on `Foldable`
298− containers and returns unit.
306+ containers for a returning-free statement.
299
307
300* `forPrepared_` is a flipped `traversePrepared_`.
308* `forPrepared_` is a flipped `traversePrepared_`.
301
309
302−* `liftPQ` lets you lift actions from `LibPQ` that require a connection
310+* `liftPQ` lets you lift actions from `Database.PostgreSQL.LibPQ` that require a connection
303 into your monad.
311 into your monad.
304
312
305To define an instance, you can minimally define only `manipulateParams`,
313To define an instance, you can minimally define only `manipulateParams`,
@@ -307,305 +315,398 @@ To define an instance, you can minimally define only `manipulateParams`,
307a default instance.
315a default instance.
308
316
309-}
317-}
310−class Monad pq => MonadPQ schema pq | pq -> schema where
318+class Monad pq => MonadPQ schemas pq | pq -> schemas where
311 manipulateParams
319 manipulateParams
312− :: ToParams x params
320+ :: (ToParams x params, All OidOfParam params)
313− => Manipulation schema params ys
321+ => Manipulation '[] schemas params ys
314− -- ^ `insertRows`, `update` or `deleteFrom`
322+ -- ^ `insertInto`, `update` or `deleteFrom`
315 -> x -> pq (K LibPQ.Result ys)
323 -> x -> pq (K LibPQ.Result ys)
316 default manipulateParams
324 default manipulateParams
317− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
325+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
318− => ToParams x params
326+ => (ToParams x params, All OidOfParam params)
319− => Manipulation schema params ys
327+ => Manipulation '[] schemas params ys
320− -- ^ `insertRows`, `update` or `deleteFrom`
328+ -- ^ `insertInto`, `update` or `deleteFrom`
321 -> x -> pq (K LibPQ.Result ys)
329 -> x -> pq (K LibPQ.Result ys)
322 manipulateParams manipulation params = lift $
330 manipulateParams manipulation params = lift $
323 manipulateParams manipulation params
331 manipulateParams manipulation params
324
332
333+ manipulateParams_
334+ :: (ToParams x params, All OidOfParam params)
335+ => Manipulation '[] schemas params '[]
336+ -- ^ `insertInto`, `update` or `deleteFrom`
337+ -> x -> pq ()
338+ manipulateParams_ q x = void $ manipulateParams q x
339+
325− manipulate :: Manipulation schema '[] ys -> pq (K LibPQ.Result ys)
340+ manipulate :: Manipulation '[] schemas '[] ys -> pq (K LibPQ.Result ys)
326 manipulate statement = manipulateParams statement ()
341 manipulate statement = manipulateParams statement ()
327
342
343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()
344+ manipulate_ = void . manipulate
345+
328 runQueryParams
346 runQueryParams
329− :: ToParams x params
347+ :: (ToParams x params, All OidOfParam params)
330− => Query schema params ys
348+ => Query '[] '[] schemas params ys
331 -- ^ `select` and friends
349 -- ^ `select` and friends
332 -> x -> pq (K LibPQ.Result ys)
350 -> x -> pq (K LibPQ.Result ys)
333 runQueryParams = manipulateParams . queryStatement
351 runQueryParams = manipulateParams . queryStatement
334
352
335 runQuery
353 runQuery
336− :: Query schema '[] ys
354+ :: Query '[] '[] schemas '[] ys
337 -- ^ `select` and friends
355 -- ^ `select` and friends
338 -> pq (K LibPQ.Result ys)
356 -> pq (K LibPQ.Result ys)
339 runQuery q = runQueryParams q ()
357 runQuery q = runQueryParams q ()
340
358
341 traversePrepared
359 traversePrepared
342− :: (ToParams x params, Traversable list)
360+ :: (ToParams x params, Traversable list, All OidOfParam params)
343− => Manipulation schema params ys
361+ => Manipulation '[] schemas params ys
344− -- ^ `insertRows`, `update`, or `deleteFrom`, and friends
362+ -- ^ `insertInto`, `update`, or `deleteFrom`, and friends
345 -> list x -> pq (list (K LibPQ.Result ys))
363 -> list x -> pq (list (K LibPQ.Result ys))
346 default traversePrepared
364 default traversePrepared
347− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
365+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
348− => (ToParams x params, Traversable list)
366+ => (ToParams x params, Traversable list, All OidOfParam params)
349− => Manipulation schema params ys -> list x -> pq (list (K LibPQ.Result ys))
367+ => Manipulation '[] schemas params ys -> list x -> pq (list (K LibPQ.Result ys))
350 traversePrepared manipulation params = lift $
368 traversePrepared manipulation params = lift $
351 traversePrepared manipulation params
369 traversePrepared manipulation params
352
370
353 forPrepared
371 forPrepared
354− :: (ToParams x params, Traversable list)
372+ :: (ToParams x params, Traversable list, All OidOfParam params)
355 => list x
373 => list x
356− -> Manipulation schema params ys
374+ -> Manipulation '[] schemas params ys
357− -- ^ `insertRows`, `update` or `deleteFrom`
375+ -- ^ `insertInto`, `update` or `deleteFrom`
358 -> pq (list (K LibPQ.Result ys))
376 -> pq (list (K LibPQ.Result ys))
359 forPrepared = flip traversePrepared
377 forPrepared = flip traversePrepared
360
378
361 traversePrepared_
379 traversePrepared_
362− :: (ToParams x params, Foldable list)
380+ :: (ToParams x params, Foldable list, All OidOfParam params)
363− => Manipulation schema params '[]
381+ => Manipulation '[] schemas params '[]
364− -- ^ `insertRows`, `update` or `deleteFrom`
382+ -- ^ `insertInto`, `update` or `deleteFrom`
365 -> list x -> pq ()
383 -> list x -> pq ()
366 default traversePrepared_
384 default traversePrepared_
367− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
385+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
368− => (ToParams x params, Foldable list)
386+ => (ToParams x params, Foldable list, All OidOfParam params)
369− => Manipulation schema params '[]
387+ => Manipulation '[] schemas params '[]
370− -- ^ `insertRows`, `update` or `deleteFrom`
388+ -- ^ `insertInto`, `update` or `deleteFrom`
371 -> list x -> pq ()
389 -> list x -> pq ()
372 traversePrepared_ manipulation params = lift $
390 traversePrepared_ manipulation params = lift $
373 traversePrepared_ manipulation params
391 traversePrepared_ manipulation params
374
392
375 forPrepared_
393 forPrepared_
376− :: (ToParams x params, Foldable list)
394+ :: (ToParams x params, Foldable list, All OidOfParam params)
377 => list x
395 => list x
378− -> Manipulation schema params '[]
396+ -> Manipulation '[] schemas params '[]
379− -- ^ `insertRows`, `update` or `deleteFrom`
397+ -- ^ `insertInto`, `update` or `deleteFrom`
380 -> pq ()
398 -> pq ()
381 forPrepared_ = flip traversePrepared_
399 forPrepared_ = flip traversePrepared_
382
400
383 liftPQ :: (LibPQ.Connection -> IO a) -> pq a
401 liftPQ :: (LibPQ.Connection -> IO a) -> pq a
384 default liftPQ
402 default liftPQ
385− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
386 => (LibPQ.Connection -> IO a) -> pq a
404 => (LibPQ.Connection -> IO a) -> pq a
387 liftPQ = lift . liftPQ
405 liftPQ = lift . liftPQ
388
406
389−instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)
407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)
390− => MonadPQ schema (PQ schema0 schema1 io) where
408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where
391
409
392 manipulateParams
410 manipulateParams
393− (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =
411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =
394 PQ $ \ (K conn) -> do
412 PQ $ \ (K conn) -> do
395 let
413 let
396− toParam' bytes = (LibPQ.invalidOid,bytes,LibPQ.Binary)
414+ paramSet
415+ :: forall param. OidOfParam param
416+ => K (Maybe Encoding.Encoding) param
417+ -> K (Maybe (LibPQ.Oid, ByteString, LibPQ.Format)) param
418+ paramSet (K maybeEncoding) = K $
419+ maybeEncoding <&> \encoding ->
420+ (oidOfParam @param, encodingBytes encoding, LibPQ.Binary)
421+ params'
422+ = hcollapse
423+ . hcmap (Proxy @OidOfParam) paramSet
397− params' = fmap (fmap toParam') (hcollapse (toParams @x @ps params))
424+ $ toParams @x @ps params
398 q' = q <> ";"
425 q' = q <> ";"
399− resultMaybe <- liftBase $ LibPQ.execParams conn q' params' LibPQ.Binary
426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary
400 case resultMaybe of
427 case resultMaybe of
401− Nothing -> error
428+ Nothing -> throw $ ResultException
402 "manipulateParams: LibPQ.execParams returned no results"
429 "manipulateParams: LibPQ.execParams returned no results"
430+ Just result -> do
431+ okResult_ result
403− Just result -> return $ K (K result)
432+ return $ K (K result)
404
433
405 traversePrepared
434 traversePrepared
406− (UnsafeManipulation q :: Manipulation schema xs ys) (list :: list x) =
435+ (UnsafeManipulation q :: Manipulation '[] schemas xs ys) (list :: list x) =
407− PQ $ \ (K conn) -> liftBase $ do
436+ PQ $ \ (K conn) -> liftIO $ do
437+ let
408− let temp = "temporary_statement"
438+ temp = "temporary_statement"
439+ paramOid :: forall p. OidOfParam p => K LibPQ.Oid p
440+ paramOid = K (oidOfParam @p)
441+ paramOids :: NP (K LibPQ.Oid) xs
442+ paramOids = hcpure (Proxy @OidOfParam) paramOid
443+ paramOids' :: [LibPQ.Oid]
444+ paramOids' = hcollapse paramOids
409− prepResultMaybe <- LibPQ.prepare conn temp q Nothing
445+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')
410 case prepResultMaybe of
446 case prepResultMaybe of
411− Nothing -> error
447+ Nothing -> throw $ ResultException
412 "traversePrepared: LibPQ.prepare returned no results"
448 "traversePrepared: LibPQ.prepare returned no results"
413− Just prepResult -> do
449+ Just prepResult -> okResult_ prepResult
414− status <- LibPQ.resultStatus prepResult
415− unless (status == LibPQ.CommandOk) . error $
416− "traversePrepared: LibPQ.prepare status " <> show status
417 results <- for list $ \ params -> do
450 results <- for list $ \ params -> do
418 let
451 let
419− toParam' bytes = (bytes,LibPQ.Binary)
452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)
420 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
453 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
421 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
454 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
422 case resultMaybe of
455 case resultMaybe of
423− Nothing -> error
456+ Nothing -> throw $ ResultException
424 "traversePrepared: LibPQ.execParams returned no results"
457 "traversePrepared: LibPQ.execParams returned no results"
458+ Just result -> do
459+ okResult_ result
425− Just result -> return $ K result
460+ return $ K result
426 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
427 case deallocResultMaybe of
462 case deallocResultMaybe of
428− Nothing -> error
463+ Nothing -> throw $ ResultException
429 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
430− Just deallocResult -> do
465+ Just deallocResult -> okResult_ deallocResult
431− status <- LibPQ.resultStatus deallocResult
432− unless (status == LibPQ.CommandOk) . error $
433− "traversePrepared: DEALLOCATE status " <> show status
434 return (K results)
466 return (K results)
435
467
436 traversePrepared_
468 traversePrepared_
437− (UnsafeManipulation q :: Manipulation schema xs '[]) (list :: list x) =
469+ (UnsafeManipulation q :: Manipulation '[] schemas xs '[]) (list :: list x) =
438− PQ $ \ (K conn) -> liftBase $ do
470+ PQ $ \ (K conn) -> liftIO $ do
471+ let
439− let temp = "temporary_statement"
472+ temp = "temporary_statement"
473+ paramOid :: forall p. OidOfParam p => K LibPQ.Oid p
474+ paramOid = K (oidOfParam @p)
475+ paramOids :: NP (K LibPQ.Oid) xs
476+ paramOids = hcpure (Proxy @OidOfParam) paramOid
477+ paramOids' :: [LibPQ.Oid]
478+ paramOids' = hcollapse paramOids
440− prepResultMaybe <- LibPQ.prepare conn temp q Nothing
479+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')
441 case prepResultMaybe of
480 case prepResultMaybe of
442− Nothing -> error
481+ Nothing -> throw $ ResultException
443 "traversePrepared_: LibPQ.prepare returned no results"
482 "traversePrepared_: LibPQ.prepare returned no results"
444− Just prepResult -> do
483+ Just prepResult -> okResult_ prepResult
445− status <- LibPQ.resultStatus prepResult
446− unless (status == LibPQ.CommandOk) . error $
447− "traversePrepared: LibPQ.prepare status " <> show status
448 for_ list $ \ params -> do
484 for_ list $ \ params -> do
449 let
485 let
450− toParam' bytes = (bytes,LibPQ.Binary)
486+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)
451 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
487 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
452 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
488 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
453 case resultMaybe of
489 case resultMaybe of
454− Nothing -> error
490+ Nothing -> throw $ ResultException
455 "traversePrepared_: LibPQ.execParams returned no results"
491 "traversePrepared_: LibPQ.execParams returned no results"
456− Just _result -> return ()
492+ Just result -> okResult_ result
457 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
493 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
458 case deallocResultMaybe of
494 case deallocResultMaybe of
459− Nothing -> error
495+ Nothing -> throw $ ResultException
460 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
496 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
461− Just deallocResult -> do
497+ Just deallocResult -> okResult_ deallocResult
462− status <- LibPQ.resultStatus deallocResult
463− unless (status == LibPQ.CommandOk) . error $
464− "traversePrepared: DEALLOCATE status " <> show status
465 return (K ())
498 return (K ())
466
499
467 liftPQ pq = PQ $ \ (K conn) -> do
500 liftPQ pq = PQ $ \ (K conn) -> do
468− y <- liftBase $ pq conn
501+ y <- liftIO $ pq conn
469 return (K y)
502 return (K y)
470
503
471−instance MonadPQ schema m => MonadPQ schema (IdentityT m)
504+instance MonadPQ schemas m => MonadPQ schemas (IdentityT m)
472−instance MonadPQ schema m => MonadPQ schema (ReaderT r m)
505+instance MonadPQ schemas m => MonadPQ schemas (ReaderT r m)
473−instance MonadPQ schema m => MonadPQ schema (Strict.StateT s m)
506+instance MonadPQ schemas m => MonadPQ schemas (Strict.StateT s m)
474−instance MonadPQ schema m => MonadPQ schema (Lazy.StateT s m)
507+instance MonadPQ schemas m => MonadPQ schemas (Lazy.StateT s m)
475−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.WriterT w m)
508+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.WriterT w m)
476−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.WriterT w m)
509+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.WriterT w m)
477−instance MonadPQ schema m => MonadPQ schema (MaybeT m)
510+instance MonadPQ schemas m => MonadPQ schemas (MaybeT m)
478−instance MonadPQ schema m => MonadPQ schema (ExceptT e m)
511+instance MonadPQ schemas m => MonadPQ schemas (ExceptT e m)
479−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.RWST r w s m)
512+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.RWST r w s m)
480−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.RWST r w s m)
513+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.RWST r w s m)
481−instance MonadPQ schema m => MonadPQ schema (ContT r m)
514+instance MonadPQ schemas m => MonadPQ schemas (ContT r m)
482−instance MonadPQ schema m => MonadPQ schema (ListT m)
515+
483−
484−instance (Monad m, schema0 ~ schema1)
516+instance (Monad m, schemas0 ~ schemas1)
485− => Applicative (PQ schema0 schema1 m) where
517+ => Applicative (PQ schemas0 schemas1 m) where
486 pure x = PQ $ \ _conn -> pure (K x)
518 pure x = PQ $ \ _conn -> pure (K x)
487 (<*>) = pqAp
519 (<*>) = pqAp
488
520
489−instance (Monad m, schema0 ~ schema1)
521+instance (Monad m, schemas0 ~ schemas1)
490− => Monad (PQ schema0 schema1 m) where
522+ => Monad (PQ schemas0 schemas1 m) where
491 return = pure
523 return = pure
492 (>>=) = flip pqBind
524 (>>=) = flip pqBind
493
525
494−instance schema0 ~ schema1 => MFunctor (PQ schema0 schema1) where
526+instance (Monad m, schemas0 ~ schemas1)
527+ => Fail.MonadFail (PQ schemas0 schemas1 m) where
528+ fail = Fail.fail
529+
530+instance schemas0 ~ schemas1 => MFunctor (PQ schemas0 schemas1) where
495 hoist f (PQ pq) = PQ (f . pq)
531 hoist f (PQ pq) = PQ (f . pq)
496
532
497−instance schema0 ~ schema1 => MonadTrans (PQ schema0 schema1) where
533+instance schemas0 ~ schemas1 => MonadTrans (PQ schemas0 schemas1) where
498 lift m = PQ $ \ _conn -> do
534 lift m = PQ $ \ _conn -> do
499 x <- m
535 x <- m
500 return (K x)
536 return (K x)
501
537
502−instance schema0 ~ schema1 => MMonad (PQ schema0 schema1) where
538+instance schemas0 ~ schemas1 => MMonad (PQ schemas0 schemas1) where
503 embed f (PQ pq) = PQ $ \ conn -> do
539 embed f (PQ pq) = PQ $ \ conn -> do
504 evalPQ (f (pq conn)) conn
540 evalPQ (f (pq conn)) conn
505
541
506−instance (MonadBase b m, schema0 ~ schema1)
542+instance (MonadIO m, schema0 ~ schema1)
507− => MonadBase b (PQ schema0 schema1 m) where
543+ => MonadIO (PQ schema0 schema1 m) where
508− liftBase = lift . liftBase
544+ liftIO = lift . liftIO
509
545
510−-- | A snapshot of the state of a `PQ` computation.
546+instance (MonadUnliftIO m, schemas0 ~ schemas1)
511−type PQRun schema =
547+ => MonadUnliftIO (PQ schemas0 schemas1 m) where
512− forall m x. Monad m => PQ schema schema m x -> m (K x schema)
548+ withRunInIO
513−
549+ :: ((forall a . PQ schemas0 schema1 m a -> IO a) -> IO b)
514−-- | Helper function in defining `MonadBaseControl` instance for `PQ`.
550+ -> PQ schemas0 schema1 m b
515−pqliftWith :: Functor m => (PQRun schema -> m a) -> PQ schema schema m a
551+ withRunInIO inner = PQ $ \conn ->
516−pqliftWith f = PQ $ \ conn ->
552+ withRunInIO $ \(run :: (forall x . m x -> IO x)) ->
517− fmap K (f $ \ pq -> unPQ pq conn)
553+ K <$> inner (\pq -> run $ unK <$> unPQ pq conn)
518−
519−instance (MonadBaseControl b m, schema0 ~ schema1)
520− => MonadBaseControl b (PQ schema0 schema1 m) where
521− type StM (PQ schema0 schema1 m) x = StM m (K x schema0)
522− liftBaseWith f =
523− pqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run
524− restoreM = PQ . const . restoreM
525
554
526-- | Get a row corresponding to a given row number from a `LibPQ.Result`,
555-- | Get a row corresponding to a given row number from a `LibPQ.Result`,
527-- throwing an exception if the row number is out of bounds.
556-- throwing an exception if the row number is out of bounds.
528getRow
557getRow
529− :: (FromRow columns y, MonadBase IO io)
558+ :: (FromRow columns y, MonadIO io)
530 => LibPQ.Row
559 => LibPQ.Row
531 -- ^ row number
560 -- ^ row number
532 -> K LibPQ.Result columns
561 -> K LibPQ.Result columns
533 -- ^ result
562 -- ^ result
534 -> io y
563 -> io y
535−getRow r (K result :: K LibPQ.Result columns) = liftBase $ do
564+getRow r (K result :: K LibPQ.Result columns) = liftIO $ do
536 numRows <- LibPQ.ntuples result
565 numRows <- LibPQ.ntuples result
537− when (numRows < r) $ error $
566+ when (numRows < r) $ throw $ ResultException $
538− "getRow: expected at least " <> show r <> "rows but only saw "
567+ "getRow: expected at least " <> pack (show r) <> "rows but only saw "
539− <> show numRows
568+ <> pack (show numRows)
540 let len = fromIntegral (lengthSList (Proxy @columns))
569 let len = fromIntegral (lengthSList (Proxy @columns))
541 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
570 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
542 case fromList row' of
571 case fromList row' of
543− Nothing -> error "getRow: found unexpected length"
572+ Nothing -> throw $ ResultException "getRow: found unexpected length"
544− Just row -> return $ fromRow @columns row
573+ Just row -> case fromRow @columns row of
574+ Left parseError -> throw $ ParseException $ "getRow: " <> parseError
575+ Right y -> return y
545
576
546-- | Intended to be used for unfolding in streaming libraries, `nextRow`
577-- | Intended to be used for unfolding in streaming libraries, `nextRow`
547-- takes a total number of rows (which can be found with `ntuples`)
578-- takes a total number of rows (which can be found with `ntuples`)
548-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,
579-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,
549-- otherwise returning the row along with the next row number.
580-- otherwise returning the row along with the next row number.
550nextRow
581nextRow
551− :: (FromRow columns y, MonadBase IO io)
582+ :: (FromRow columns y, MonadIO io)
552 => LibPQ.Row -- ^ total number of rows
583 => LibPQ.Row -- ^ total number of rows
553 -> K LibPQ.Result columns -- ^ result
584 -> K LibPQ.Result columns -- ^ result
554 -> LibPQ.Row -- ^ row number
585 -> LibPQ.Row -- ^ row number
555 -> io (Maybe (LibPQ.Row,y))
586 -> io (Maybe (LibPQ.Row,y))
556nextRow total (K result :: K LibPQ.Result columns) r
587nextRow total (K result :: K LibPQ.Result columns) r
557− = liftBase $ if r >= total then return Nothing else do
588+ = liftIO $ if r >= total then return Nothing else do
558 let len = fromIntegral (lengthSList (Proxy @columns))
589 let len = fromIntegral (lengthSList (Proxy @columns))
559 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
590 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
560 case fromList row' of
591 case fromList row' of
561− Nothing -> error "nextRow: found unexpected length"
592+ Nothing -> throw $ ResultException "nextRow: found unexpected length"
593+ Just row -> case fromRow @columns row of
594+ Left parseError -> throw $ ParseException $ "nextRow: " <> parseError
562− Just row -> return $ Just (r+1, fromRow @columns row)
595+ Right y -> return $ Just (r+1, y)
563
596
564-- | Get all rows from a `LibPQ.Result`.
597-- | Get all rows from a `LibPQ.Result`.
565getRows
598getRows
566− :: (FromRow columns y, MonadBase IO io)
599+ :: (FromRow columns y, MonadIO io)
567 => K LibPQ.Result columns -- ^ result
600 => K LibPQ.Result columns -- ^ result
568 -> io [y]
601 -> io [y]
569−getRows (K result :: K LibPQ.Result columns) = liftBase $ do
602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do
570 let len = fromIntegral (lengthSList (Proxy @columns))
603 let len = fromIntegral (lengthSList (Proxy @columns))
571 numRows <- LibPQ.ntuples result
604 numRows <- LibPQ.ntuples result
572 for [0 .. numRows - 1] $ \ r -> do
605 for [0 .. numRows - 1] $ \ r -> do
573 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
606 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
574 case fromList row' of
607 case fromList row' of
575− Nothing -> error "getRows: found unexpected length"
608+ Nothing -> throw $ ResultException "getRows: found unexpected length"
576− Just row -> return $ fromRow @columns row
609+ Just row -> case fromRow @columns row of
610+ Left parseError -> throw $ ParseException $ "getRows: " <> parseError
611+ Right y -> return y
577
612
578-- | Get the first row if possible from a `LibPQ.Result`.
613-- | Get the first row if possible from a `LibPQ.Result`.
579firstRow
614firstRow
580− :: (FromRow columns y, MonadBase IO io)
615+ :: (FromRow columns y, MonadIO io)
581 => K LibPQ.Result columns -- ^ result
616 => K LibPQ.Result columns -- ^ result
582 -> io (Maybe y)
617 -> io (Maybe y)
583−firstRow (K result :: K LibPQ.Result columns) = liftBase $ do
618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do
584 numRows <- LibPQ.ntuples result
619 numRows <- LibPQ.ntuples result
585 if numRows <= 0 then return Nothing else do
620 if numRows <= 0 then return Nothing else do
586 let len = fromIntegral (lengthSList (Proxy @columns))
621 let len = fromIntegral (lengthSList (Proxy @columns))
587 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]
622 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]
588 case fromList row' of
623 case fromList row' of
589− Nothing -> error "firstRow: found unexpected length"
624+ Nothing -> throw $ ResultException "firstRow: found unexpected length"
590− Just row -> return . Just $ fromRow @columns row
625+ Just row -> case fromRow @columns row of
626+ Left parseError -> throw $ ParseException $ "firstRow: " <> parseError
627+ Right y -> return $ Just y
591
628
592-- | Lifts actions on results from @LibPQ@.
629-- | Lifts actions on results from @LibPQ@.
593liftResult
630liftResult
594− :: MonadBase IO io
631+ :: MonadIO io
595 => (LibPQ.Result -> IO x)
632 => (LibPQ.Result -> IO x)
596 -> K LibPQ.Result results -> io x
633 -> K LibPQ.Result results -> io x
597−liftResult f (K result) = liftBase $ f result
634+liftResult f (K result) = liftIO $ f result
598
635
599-- | Returns the number of rows (tuples) in the query result.
636-- | Returns the number of rows (tuples) in the query result.
600−ntuples :: MonadBase IO io => K LibPQ.Result columns -> io LibPQ.Row
637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row
601ntuples = liftResult LibPQ.ntuples
638ntuples = liftResult LibPQ.ntuples
602
639
603-- | Returns the result status of the command.
640-- | Returns the result status of the command.
604−resultStatus :: MonadBase IO io => K LibPQ.Result results -> io LibPQ.ExecStatus
641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus
605resultStatus = liftResult LibPQ.resultStatus
642resultStatus = liftResult LibPQ.resultStatus
606
643
607-- | Returns the error message most recently generated by an operation
644-- | Returns the error message most recently generated by an operation
608-- on the connection.
645-- on the connection.
609resultErrorMessage
646resultErrorMessage
610− :: MonadBase IO io => K LibPQ.Result results -> io (Maybe ByteString)
647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)
611resultErrorMessage = liftResult LibPQ.resultErrorMessage
648resultErrorMessage = liftResult LibPQ.resultErrorMessage
649+
650+-- | Returns the error code most recently generated by an operation
651+-- on the connection.
652+--
653+-- https://www.postgresql.org/docs/current/static/errcodes-appendix.html
654+resultErrorCode
655+ :: MonadIO io
656+ => K LibPQ.Result results
657+ -> io (Maybe ByteString)
658+resultErrorCode = liftResult (flip LibPQ.resultErrorField LibPQ.DiagSqlstate)
659+
660+-- | the state of LibPQ
661+data PQState = PQState
662+ { sqlExecStatus :: LibPQ.ExecStatus
663+ , sqlStateCode :: Maybe ByteString
664+ -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html
665+ , sqlErrorMessage :: Maybe ByteString
666+ } deriving (Eq, Show)
667+
668+-- | `Exception`s that can be thrown by Squeal.
669+data SquealException
670+ = PQException PQState
671+ | ResultException Text
672+ | ParseException Text
673+ deriving (Eq, Show)
674+instance Exception SquealException
675+
676+okResult_ :: MonadIO io => LibPQ.Result -> io ()
677+okResult_ result = liftIO $ do
678+ status <- LibPQ.resultStatus result
679+ case status of
680+ LibPQ.CommandOk -> return ()
681+ LibPQ.TuplesOk -> return ()
682+ _ -> do
683+ stateCode <- LibPQ.resultErrorField result LibPQ.DiagSqlstate
684+ msg <- LibPQ.resultErrorMessage result
685+ throw . PQException $ PQState status stateCode msg
686+
687+-- | Check if a `LibPQ.Result`'s status is either `LibPQ.CommandOk`
688+-- or `LibPQ.TuplesOk` otherwise `throw` a `PQException`.
689+okResult :: MonadIO io => K LibPQ.Result row -> io ()
690+okResult = okResult_ . unK
691+
692+-- | Catch `SquealException`s.
693+catchSqueal
694+ :: MonadUnliftIO io
695+ => io a
696+ -> (SquealException -> io a) -- ^ handler
697+ -> io a
698+catchSqueal = catch
699+
700+-- | Handle `SquealException`s.
701+handleSqueal
702+ :: MonadUnliftIO io
703+ => (SquealException -> io a) -- ^ handler
704+ -> io a -> io a
705+handleSqueal = handle
706+
707+-- | `Either` return a `SquealException` or a result.
708+trySqueal
709+ :: MonadUnliftIO io
710+ => io a
711+ -> io (Either SquealException a)
712+trySqueal = try
squeal-postgresql/src/Squeal/PostgreSQL/Pool.hs+69−79
@@ -1,17 +1,40 @@
1{-|
1{-|
2−Module: Squeal.PostgreSQL.Definition
2+Module: Squeal.PostgreSQL.Pool
3−Description: Pooled connections
3+Description: Connection pools
4Copyright: (c) Eitan Chatav, 2017
4Copyright: (c) Eitan Chatav, 2017
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
8−A `MonadPQ` for pooled connections.
8+Connection pools.
9+
10+Typical use case would be to create your pool using `createConnectionPool`
11+and run anything that requires the pool connection with `usingConnectionPool`.
12+
13+Here's a simplified example:
14+
15+>>> import Squeal.PostgreSQL
16+
17+>>> :{
18+do
19+ let
20+ query :: Query_ (Public '[]) () (Only Char)
21+ query = values_ (literal 'a' `as` #fromOnly)
22+ pool <- createConnectionPool "host=localhost port=5432 dbname=exampledb" 1 0.5 10
23+ chr <- usingConnectionPool pool $ do
24+ result <- runQuery query
25+ Just (Only a) <- firstRow result
26+ return a
27+ destroyConnectionPool pool
28+ putChar chr
29+:}
30+a
9-}
31-}
10
32
11{-# LANGUAGE
33{-# LANGUAGE
12 DeriveFunctor
34 DeriveFunctor
13 , FlexibleContexts
35 , FlexibleContexts
14 , FlexibleInstances
36 , FlexibleInstances
37+ , InstanceSigs
15 , MultiParamTypeClasses
38 , MultiParamTypeClasses
16 , RankNTypes
39 , RankNTypes
17 , ScopedTypeVariables
40 , ScopedTypeVariables
@@ -22,34 +45,24 @@ A `MonadPQ` for pooled connections.
22
45
23module Squeal.PostgreSQL.Pool
46module Squeal.PostgreSQL.Pool
24 ( -- * Pools
47 ( -- * Pools
25− PoolPQ (..)
48+ Pool
26 , createConnectionPool
49 , createConnectionPool
27− , Pool
50+ , usingConnectionPool
28− , destroyAllResources
51+ , destroyConnectionPool
29− , PoolPQRun
30− , poolpqliftWith
31 ) where
52 ) where
32
53
33−import Control.Monad.Base
34−import Control.Monad.Trans
35−import Control.Monad.Trans.Control
36import Data.ByteString
54import Data.ByteString
37−import Data.Pool
38import Data.Time
55import Data.Time
39−import Generics.SOP (K(..))
56+import Generics.SOP (K(..), unK)
57+import UnliftIO (MonadUnliftIO (..))
58+import UnliftIO.Pool (Pool, createPool, destroyAllResources, withResource)
40
59
41import Squeal.PostgreSQL.PQ
60import Squeal.PostgreSQL.PQ
42−import Squeal.PostgreSQL.Schema
43−
44−-- | `PoolPQ` @schema@ should be a drop-in replacement for `PQ` @schema schema@.
45−newtype PoolPQ (schema :: SchemaType) m x =
46− PoolPQ { runPoolPQ :: Pool (K Connection schema) -> m x }
47− deriving Functor
48
61
49-- | Create a striped pool of connections.
62-- | Create a striped pool of connections.
50-- Although the garbage collector will destroy all idle connections when the pool is garbage collected it's recommended to manually `destroyAllResources` when you're done with the pool so that the connections are freed up as soon as possible.
63-- Although the garbage collector will destroy all idle connections when the pool is garbage collected it's recommended to manually `destroyAllResources` when you're done with the pool so that the connections are freed up as soon as possible.
51createConnectionPool
64createConnectionPool
52− :: MonadBase IO io
65+ :: MonadUnliftIO io
53 => ByteString
66 => ByteString
54 -- ^ The passed string can be empty to use all default parameters, or it can
67 -- ^ The passed string can be empty to use all default parameters, or it can
55 -- contain one or more parameter settings separated by whitespace.
68 -- contain one or more parameter settings separated by whitespace.
@@ -65,68 +78,45 @@ createConnectionPool
65 -> Int
78 -> Int
66 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.
79 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.
67 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.
80 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.
68− -> io (Pool (K Connection schema))
81+ -> io (Pool (K Connection schemas))
69−createConnectionPool conninfo stripes idle maxResrc = liftBase $
82+createConnectionPool conninfo stripes idle maxResrc =
70 createPool (connectdb conninfo) finish stripes idle maxResrc
83 createPool (connectdb conninfo) finish stripes idle maxResrc
71
84
72−-- | `Applicative` instance for `PoolPQ`.
85+{-|
73−instance Monad m => Applicative (PoolPQ schema m) where
86+Temporarily take a connection from a `Pool`, perform an action with it,
74− pure x = PoolPQ $ \ _ -> pure x
87+and return it to the pool afterwards.
75− PoolPQ f <*> PoolPQ x = PoolPQ $ \ pool -> do
76− f' <- f pool
77− x' <- x pool
78− return $ f' x'
79−
80−-- | `Monad` instance for `PoolPQ`.
81−instance Monad m => Monad (PoolPQ schema m) where
82− return = pure
83− PoolPQ x >>= f = PoolPQ $ \ pool -> do
84− x' <- x pool
85− runPoolPQ (f x') pool
86−
87−-- | `MonadTrans` instance for `PoolPQ`.
88−instance MonadTrans (PoolPQ schema) where
89− lift m = PoolPQ $ \ _pool -> m
90−
91−-- | `MonadBase` instance for `PoolPQ`.
92−instance MonadBase b m => MonadBase b (PoolPQ schema m) where
93− liftBase = lift . liftBase
94
88
95−-- | `MonadPQ` instance for `PoolPQ`.
89+If the pool has an idle connection available, it is used immediately.
96−instance MonadBaseControl IO io => MonadPQ schema (PoolPQ schema io) where
90+Otherwise, if the maximum number of connections has not yet been reached,
97− manipulateParams manipulation params = PoolPQ $ \ pool -> do
91+a new connection is created and used.
98− withResource pool $ \ conn -> do
92+If the maximum number of connections has been reached, this function blocks
99− (K result :: K (K Result ys) schema) <- flip unPQ conn $
93+until a connection becomes available.
100− manipulateParams manipulation params
94+-}
101− return result
95+usingConnectionPool
102− traversePrepared manipulation params = PoolPQ $ \ pool ->
96+ :: MonadUnliftIO io
103− withResource pool $ \ conn -> do
97+ => Pool (K Connection schemas) -- ^ pool
104− (K result :: K (list (K Result ys)) schema) <- flip unPQ conn $
98+ -> PQ schemas schemas io x -- ^ session
105− traversePrepared manipulation params
99+ -> io x
106− return result
107− traversePrepared_ manipulation params = PoolPQ $ \ pool -> do
108− withResource pool $ \ conn -> do
109− (_ :: K () schema) <- flip unPQ conn $
110− traversePrepared_ manipulation params
111− return ()
112− liftPQ m = PoolPQ $ \ pool ->
113− withResource pool $ \ conn -> do
100+usingConnectionPool pool (PQ session) = unK <$> withResource pool session
114− (K result :: K result schema) <- flip unPQ conn $
115− liftPQ m
116− return result
117
101
118−-- | A snapshot of the state of a `PoolPQ` computation.
102+{- |
119−type PoolPQRun schema =
103+Destroy all connections in all stripes in the pool.
120− forall m x. Monad m => PoolPQ schema m x -> m x
104+Note that this will ignore any exceptions in the destroy function.
121
105
122−-- | Helper function in defining `MonadBaseControl` instance for `PoolPQ`.
106+This function is useful when you detect that all connections
123−poolpqliftWith :: Functor m => (PoolPQRun schema -> m a) -> PoolPQ schema m a
107+in the pool are broken. For example after a database has been
124−poolpqliftWith f = PoolPQ $ \ pool ->
108+restarted all connections opened before the restart will be broken.
125− (f $ \ pq -> runPoolPQ pq pool)
109+In that case it's better to close those connections so that
110+`usingConnectionPool` won't take a broken connection from the pool
111+but will open a new connection instead.
126
112
127−-- | `MonadBaseControl` instance for `PoolPQ`.
113+Another use-case for this function is that when you know you are done
128−instance MonadBaseControl b m => MonadBaseControl b (PoolPQ schema m) where
114+with the pool you can destroy all idle connections immediately
129− type StM (PoolPQ schema m) x = StM m x
115+instead of waiting on the garbage collector to destroy them,
130− liftBaseWith f =
116+thus freeing up those connections sooner.
131− poolpqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run
117+-}
132− restoreM = PoolPQ . const . restoreM
118+destroyConnectionPool
119+ :: MonadUnliftIO io
120+ => Pool (K Connection schemas) -- ^ pool
121+ -> io ()
122+destroyConnectionPool = destroyAllResources
squeal-postgresql/src/Squeal/PostgreSQL/Query.hs+678−552
@@ -1,7 +1,7 @@
1{-|
1{-|
2Module: Squeal.PostgreSQL.Query
2Module: Squeal.PostgreSQL.Query
3Description: Squeal queries
3Description: Squeal queries
4−Copyright: (c) Eitan Chatav, 2017
4+Copyright: (c) Eitan Chatav, 2019
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
@@ -9,81 +9,81 @@ Squeal queries.
9-}
9-}
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12+ ConstraintKinds
12− DeriveGeneric
13+ , DeriveGeneric
13 , FlexibleContexts
14 , FlexibleContexts
15+ , FlexibleInstances
14 , GADTs
16 , GADTs
15 , GeneralizedNewtypeDeriving
17 , GeneralizedNewtypeDeriving
16 , LambdaCase
18 , LambdaCase
19+ , MultiParamTypeClasses
20+ , OverloadedLabels
17 , OverloadedStrings
21 , OverloadedStrings
22+ , QuantifiedConstraints
23+ , ScopedTypeVariables
18 , StandaloneDeriving
24 , StandaloneDeriving
25+ , TypeApplications
26+ , TypeFamilies
19 , TypeInType
27 , TypeInType
20 , TypeOperators
28 , TypeOperators
29+ , RankNTypes
30+ , UndecidableInstances
21−#-}
31+ #-}
22
32
23module Squeal.PostgreSQL.Query
33module Squeal.PostgreSQL.Query
24 ( -- * Queries
34 ( -- * Queries
25− Query (UnsafeQuery, renderQuery)
35+ Query_
36+ , Query (..)
37+ -- ** Select
38+ , select
39+ , select_
40+ , selectDistinct
41+ , selectDistinct_
42+ , selectDistinctOn
43+ , selectDistinctOn_
44+ , Selection (..)
45+ -- ** Values
46+ , values
47+ , values_
48+ -- ** Set Operations
26 , union
49 , union
27 , unionAll
50 , unionAll
28 , intersect
51 , intersect
29 , intersectAll
52 , intersectAll
30 , except
53 , except
31 , exceptAll
54 , exceptAll
32− -- * Select
55+ -- ** With
33− , select
56+ , With (..)
34− , selectDistinct
57+ , CommonTableExpression (..)
35− , selectStar
58+ , withRecursive
36− , selectDistinctStar
37− , selectDotStar
38− , selectDistinctDotStar
39− , values
40− , values_
41 -- * Table Expressions
59 -- * Table Expressions
42 , TableExpression (..)
60 , TableExpression (..)
43− , renderTableExpression
44 , from
61 , from
45 , where_
62 , where_
46− , group
63+ , groupBy
47 , having
64 , having
48− , orderBy
49 , limit
65 , limit
50 , offset
66 , offset
51− -- ** JSON table expressions
52− , PGjson_each
53− , PGjsonb_each
54− , jsonEach
55− , jsonbEach
56− , jsonEachAsText
57− , jsonbEachAsText
58− , jsonPopulateRecordAs
59− , jsonbPopulateRecordAs
60− , jsonPopulateRecordSetAs
61− , jsonbPopulateRecordSetAs
62− -- * From
67+ -- * From Clauses
63 , FromClause (..)
68 , FromClause (..)
64 , table
69 , table
65 , subquery
70 , subquery
66 , view
71 , view
72+ , common
67 , crossJoin
73 , crossJoin
68 , innerJoin
74 , innerJoin
69 , leftOuterJoin
75 , leftOuterJoin
70 , rightOuterJoin
76 , rightOuterJoin
71 , fullOuterJoin
77 , fullOuterJoin
72 -- * Grouping
78 -- * Grouping
73− , By (By, By2)
79+ , By (..)
74− , renderBy
75− , GroupByClause (NoGroups, Group)
80+ , GroupByClause (..)
76− , renderGroupByClause
77− , HavingClause (NoHaving, Having)
81+ , HavingClause (..)
78− , renderHavingClause
79− -- * Sorting
80− , SortExpression (..)
81− , renderSortExpression
82 ) where
82 ) where
83
83
84import Control.DeepSeq
84import Control.DeepSeq
85import Data.ByteString (ByteString)
85import Data.ByteString (ByteString)
86−import Data.Monoid hiding (All)
86+import Data.Kind (Type)
87import Data.String
87import Data.String
88import Data.Word
88import Data.Word
89import Generics.SOP hiding (from)
89import Generics.SOP hiding (from)
@@ -91,25 +91,76 @@ import GHC.TypeLits
91
91
92import qualified GHC.Generics as GHC
92import qualified GHC.Generics as GHC
93
93
94+import Squeal.PostgreSQL.Alias
94import Squeal.PostgreSQL.Expression
95import Squeal.PostgreSQL.Expression
96+import Squeal.PostgreSQL.Expression.Logic
97+import Squeal.PostgreSQL.Expression.Sort
98+import Squeal.PostgreSQL.Expression.Window
99+import Squeal.PostgreSQL.List
100+import Squeal.PostgreSQL.PG
95import Squeal.PostgreSQL.Render
101import Squeal.PostgreSQL.Render
96import Squeal.PostgreSQL.Schema
102import Squeal.PostgreSQL.Schema
97
103
104+-- $setup
105+-- >>> import Squeal.PostgreSQL
106+-- >>> import Data.Int (Int32, Int64)
107+-- >>> import Data.Monoid (Sum (..))
108+-- >>> import Data.Text (Text)
109+-- >>> import qualified Generics.SOP as SOP
110+
111+{- |
112+The process of retrieving or the command to retrieve data from
113+a database is called a `Query`.
114+
115+The general `Query` type is parameterized by
116+
117+* @outer :: FromType@ - outer scope for a correlated subquery,
118+* @commons :: FromType@ - scope for all `common` table expressions,
119+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,
120+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,
121+* @row :: RowType@ - return type of the `Query`.
122+-}
123+newtype Query
124+ (outer :: FromType)
125+ (commons :: FromType)
126+ (schemas :: SchemasType)
127+ (params :: [NullityType])
128+ (row :: RowType)
129+ = UnsafeQuery { renderQuery :: ByteString }
130+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
131+instance RenderSQL (Query outer commons schemas params row) where renderSQL = renderQuery
132+
98{- |
133{- |
99−The process of retrieving or the command to retrieve data from a database
134+The top level `Query_` type is parameterized by a @schemas@ `SchemasType`,
100−is called a `Query`. The `select`, `selectStar`, `selectDotStar`,
135+against which the query is type-checked, an input @parameters@ Haskell `Type`,
101−`selectDistinct`, `selectDistinctStar` and `selectDistinctDotStar` commands
136+and an ouput row Haskell `Type`.
102−are used to specify queries.
137+
138+A top-level query can be run
139+using `Squeal.PostgreSQL.PQ.runQueryParams`, or if @parameters = ()@
140+using `Squeal.PostgreSQL.PQ.runQuery`.
141+
142+Generally, @parameters@ will be a Haskell tuple or record whose entries
143+may be referenced using positional
144+`Squeal.PostgreSQL.Expression.Parameter.parameter`s and @row@ will be a
145+Haskell record, whose entries will be targeted using overloaded labels.
146+
147+Let's see some examples of queries.
148+
149+>>> :set -XDeriveAnyClass -XDerivingStrategies
150+>>> :{
151+data Row a b = Row { col1 :: a, col2 :: b }
152+ deriving stock (GHC.Generic)
153+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
154+:}
103
155
104simple query:
156simple query:
105
157
158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]
159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
106>>> :{
160>>> :{
107let
161let
108− query :: Query
162+ query :: Query_ (Public Schema) () (Row Int32 Int32)
109− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
110− '[]
111− '["col" ::: 'Null 'PGint4]
112− query = selectStar (from (table #tab))
163+ query = select Star (from (table #tab))
113in printSQL query
164in printSQL query
114:}
165:}
115SELECT * FROM "tab" AS "tab"
166SELECT * FROM "tab" AS "tab"
@@ -118,34 +169,22 @@ restricted query:
118
169
119>>> :{
170>>> :{
120let
171let
121− query :: Query
172+ query :: Query_ (Public Schema) () (Row Int32 Int32)
122− '[ "tab" ::: 'Table ('[] :=>
123− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
124− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]
125− '[]
126− '[ "sum" ::: 'NotNull 'PGint4
127− , "col1" ::: 'NotNull 'PGint4 ]
128 query =
173 query =
129− select
130− ((#col1 + #col2) `As` #sum :* #col1 :* Nil)
174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)
131 ( from (table #tab)
175 ( from (table #tab)
132 & where_ (#col1 .> #col2)
176 & where_ (#col1 .> #col2)
133 & where_ (#col2 .> 0) )
177 & where_ (#col2 .> 0) )
134in printSQL query
178in printSQL query
135:}
179:}
136−SELECT ("col1" + "col2") AS "sum", "col1" AS "col1" FROM "tab" AS "tab" WHERE (("col1" > "col2") AND ("col2" > 0))
180+SELECT ("col1" + "col2") AS "col1", "col1" AS "col2" FROM "tab" AS "tab" WHERE (("col1" > "col2") AND ("col2" > 0))
137
181
138subquery:
182subquery:
139
183
140>>> :{
184>>> :{
141let
185let
142− query :: Query
186+ query :: Query_ (Public Schema) () (Row Int32 Int32)
143− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
144− '[]
145− '["col" ::: 'Null 'PGint4]
146− query =
147− selectStar
148− (from (subquery (selectStar (from (table #tab)) `As` #sub)))
187+ query = select Star (from (subquery (select Star (from (table #tab)) `as` #sub)))
149in printSQL query
188in printSQL query
150:}
189:}
151SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"
190SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"
@@ -154,12 +193,8 @@ limits and offsets:
154
193
155>>> :{
194>>> :{
156let
195let
157− query :: Query
196+ query :: Query_ (Public Schema) () (Row Int32 Int32)
158− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
159− '[]
160− '["col" ::: 'Null 'PGint4]
161− query = selectStar
162− (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)
197+ query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)
163in printSQL query
198in printSQL query
164:}
199:}
165SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4
200SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4
@@ -168,276 +203,426 @@ parameterized query:
168
203
169>>> :{
204>>> :{
170let
205let
171− query :: Query
206+ query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)
172− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8])]
173− '[ 'NotNull 'PGfloat8]
174− '["col" ::: 'NotNull 'PGfloat8]
175− query = selectStar
176− (from (table #tab) & where_ (#col .> param @1))
207+ query = select Star (from (table #tab) & where_ (#col1 .> param @1))
177in printSQL query
208in printSQL query
178:}
209:}
179−SELECT * FROM "tab" AS "tab" WHERE ("col" > ($1 :: float8))
210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))
180
211
181aggregation query:
212aggregation query:
182
213
183>>> :{
214>>> :{
184let
215let
185− query :: Query
216+ query :: Query_ (Public Schema) () (Row Int64 Int32)
186− '[ "tab" ::: 'Table ('[] :=>
187− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
188− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]
189− '[]
190− '[ "sum" ::: 'NotNull 'PGint4
191− , "col1" ::: 'NotNull 'PGint4 ]
192 query =
217 query =
193− select (sum_ #col2 `As` #sum :* #col1 :* Nil)
218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)
194− ( from (table (#tab `As` #table1))
219+ ( from (table (#tab `as` #table1))
195− & group (By #col1 :* Nil)
220+ & groupBy #col1
196− & having (#col1 + sum_ #col2 .> 1) )
221+ & having (sum_ (Distinct #col2) .> 1) )
197in printSQL query
222in printSQL query
198:}
223:}
199−SELECT sum("col2") AS "sum", "col1" AS "col1" FROM "tab" AS "table1" GROUP BY "col1" HAVING (("col1" + sum("col2")) > 1)
224+SELECT COALESCE(sum(ALL "col2"), 0) AS "col1", "col1" AS "col2" FROM "tab" AS "table1" GROUP BY "col1" HAVING (sum(DISTINCT "col2") > 1)
200
225
201sorted query:
226sorted query:
202
227
203>>> :{
228>>> :{
204let
229let
205− query :: Query
230+ query :: Query_ (Public Schema) () (Row Int32 Int32)
206− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
207− '[]
208− '["col" ::: 'Null 'PGint4]
209− query = selectStar
210− (from (table #tab) & orderBy [#col & AscNullsFirst])
231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])
211in printSQL query
232in printSQL query
212:}
233:}
213−SELECT * FROM "tab" AS "tab" ORDER BY "col" ASC NULLS FIRST
234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC
214
235
215joins:
236joins:
216
237
217−>>> :set -XFlexibleContexts
238+>>> :{
239+type OrdersColumns =
240+ '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
241+ , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4
242+ , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4
243+ , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4 ]
244+:}
245+
246+>>> :{
247+type OrdersConstraints =
248+ '["pk_orders" ::: PrimaryKey '["id"]
249+ ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]
250+ ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"] ]
251+:}
252+
253+>>> type NamesColumns = '["id" ::: 'NoDef :=> 'NotNull 'PGint4, "name" ::: 'NoDef :=> 'NotNull 'PGtext]
254+>>> type CustomersConstraints = '["pk_customers" ::: PrimaryKey '["id"]]
255+>>> type ShippersConstraints = '["pk_shippers" ::: PrimaryKey '["id"]]
256+>>> :{
257+type OrdersSchema =
258+ '[ "orders" ::: 'Table (OrdersConstraints :=> OrdersColumns)
259+ , "customers" ::: 'Table (CustomersConstraints :=> NamesColumns)
260+ , "shippers" ::: 'Table (ShippersConstraints :=> NamesColumns) ]
261+:}
262+
263+>>> :{
264+data Order = Order
265+ { price :: Float
266+ , customerName :: Text
267+ , shipperName :: Text
268+ } deriving GHC.Generic
269+instance SOP.Generic Order
270+instance SOP.HasDatatypeInfo Order
271+:}
272+
218>>> :{
273>>> :{
219let
274let
220− query :: Query
275+ query :: Query_ (Public OrdersSchema) () Order
221− '[ "orders" ::: 'Table (
222− '["pk_orders" ::: PrimaryKey '["id"]
223− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]
224− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>
225− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
226− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4
227− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4
228− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4
229− ])
230− , "customers" ::: 'Table (
231− '["pk_customers" ::: PrimaryKey '["id"]] :=>
232− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
233− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
234− ])
235− , "shippers" ::: 'Table (
236− '["pk_shippers" ::: PrimaryKey '["id"]] :=>
237− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
238− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
239− ])
240− ]
241− '[]
242− '[ "order_price" ::: 'NotNull 'PGfloat4
243− , "customer_name" ::: 'NotNull 'PGtext
244− , "shipper_name" ::: 'NotNull 'PGtext
245− ]
246− query = select
276+ query = select_
247− ( #o ! #price `As` #order_price :*
277+ ( #o ! #price `as` #price :*
248− #c ! #name `As` #customer_name :*
278+ #c ! #name `as` #customerName :*
249− #s ! #name `As` #shipper_name :* Nil )
279+ #s ! #name `as` #shipperName )
250− ( from (table (#orders `As` #o)
280+ ( from (table (#orders `as` #o)
251− & innerJoin (table (#customers `As` #c))
281+ & innerJoin (table (#customers `as` #c))
252 (#o ! #customer_id .== #c ! #id)
282 (#o ! #customer_id .== #c ! #id)
253− & innerJoin (table (#shippers `As` #s))
283+ & innerJoin (table (#shippers `as` #s))
254 (#o ! #shipper_id .== #s ! #id)) )
284 (#o ! #shipper_id .== #s ! #id)) )
255in printSQL query
285in printSQL query
256:}
286:}
257−SELECT "o"."price" AS "order_price", "c"."name" AS "customer_name", "s"."name" AS "shipper_name" FROM "orders" AS "o" INNER JOIN "customers" AS "c" ON ("o"."customer_id" = "c"."id") INNER JOIN "shippers" AS "s" ON ("o"."shipper_id" = "s"."id")
287+SELECT "o"."price" AS "price", "c"."name" AS "customerName", "s"."name" AS "shipperName" FROM "orders" AS "o" INNER JOIN "customers" AS "c" ON ("o"."customer_id" = "c"."id") INNER JOIN "shippers" AS "s" ON ("o"."shipper_id" = "s"."id")
258
288
259self-join:
289self-join:
260
290
261>>> :{
291>>> :{
262let
292let
263− query :: Query
293+ query :: Query_ (Public Schema) () (Row Int32 Int32)
264− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
294+ query = select
265− '[]
295+ (#t1 & DotStar)
266− '["col" ::: 'Null 'PGint4]
267− query = selectDotStar #t1
268− (from (table (#tab `As` #t1) & crossJoin (table (#tab `As` #t2))))
296+ (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))
269in printSQL query
297in printSQL query
270:}
298:}
271SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"
299SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"
272
300
301+value queries:
302+
303+>>> :{
304+let
305+ query :: Query_ schemas () (Row String Bool)
306+ query = values
307+ ("true" `as` #col1 :* true `as` #col2)
308+ ["false" `as` #col1 :* false `as` #col2]
309+in printSQL query
310+:}
311+SELECT * FROM (VALUES (E'true', TRUE), (E'false', FALSE)) AS t ("col1", "col2")
312+
273set operations:
313set operations:
274
314
275>>> :{
315>>> :{
276let
316let
277− query :: Query
317+ query :: Query_ (Public Schema) () (Row Int32 Int32)
278− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
318+ query = select Star (from (table #tab)) `unionAll` select Star (from (table #tab))
279− '[]
280− '["col" ::: 'Null 'PGint4]
281− query =
282− selectStar (from (table #tab))
283− `unionAll`
284− selectStar (from (table #tab))
285in printSQL query
319in printSQL query
286:}
320:}
287(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")
321(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")
322+
323+with queries:
324+
325+>>> :{
326+let
327+ query :: Query_ (Public Schema) () (Row Int32 Int32)
328+ query = with (
329+ select Star (from (table #tab)) `as` #cte1 :>>
330+ select Star (from (common #cte1)) `as` #cte2
331+ ) (select Star (from (common #cte2)))
332+in printSQL query
333+:}
334+WITH "cte1" AS (SELECT * FROM "tab" AS "tab"), "cte2" AS (SELECT * FROM "cte1" AS "cte1") SELECT * FROM "cte2" AS "cte2"
335+
336+window function queries
337+
338+>>> :{
339+let
340+ query :: Query_ (Public Schema) () (Row Int32 Int64)
341+ query = select
342+ (#col1 & Also (rank `as` #col2 `Over` (partitionBy #col1 & orderBy [#col2 & Asc])))
343+ (from (table #tab))
344+in printSQL query
345+:}
346+SELECT "col1" AS "col1", rank() OVER (PARTITION BY "col1" ORDER BY "col2" ASC) AS "col2" FROM "tab" AS "tab"
347+
348+correlated subqueries
349+
350+>>> :{
351+let
352+ query :: Query_ (Public Schema) () (Only Int32)
353+ query =
354+ select (#col1 `as` #fromOnly) (from (table (#tab `as` #t1))
355+ & where_ (exists (
356+ select Star (from (table (#tab `as` #t2))
357+ & where_ (#t2 ! #col2 .== #t1 ! #col1)))))
358+in printSQL query
359+:}
360+SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))
361+
288-}
362-}
289−newtype Query
363+type family Query_
290− (schema :: SchemaType)
364+ (schemas :: SchemasType)
291− (params :: [NullityType])
365+ (parameters :: Type)
292− (columns :: RelationType)
366+ (row :: Type) where
293− = UnsafeQuery { renderQuery :: ByteString }
367+ Query_ schemas params row =
294− deriving (GHC.Generic,Show,Eq,Ord,NFData)
368+ Query '[] '[] schemas (TuplePG params) (RowPG row)
295−instance RenderSQL (Query schema params columns) where renderSQL = renderQuery
296
369
297-- | The results of two queries can be combined using the set operation
370-- | The results of two queries can be combined using the set operation
298-- `union`. Duplicate rows are eliminated.
371-- `union`. Duplicate rows are eliminated.
299union
372union
300− :: Query schema params columns
373+ :: Query outer commons schemas params columns
301− -> Query schema params columns
374+ -> Query outer commons schemas params columns
302− -> Query schema params columns
375+ -> Query outer commons schemas params columns
303q1 `union` q2 = UnsafeQuery $
376q1 `union` q2 = UnsafeQuery $
304− parenthesized (renderQuery q1)
377+ parenthesized (renderSQL q1)
305 <+> "UNION"
378 <+> "UNION"
306− <+> parenthesized (renderQuery q2)
379+ <+> parenthesized (renderSQL q2)
307
380
308-- | The results of two queries can be combined using the set operation
381-- | The results of two queries can be combined using the set operation
309-- `unionAll`, the disjoint union. Duplicate rows are retained.
382-- `unionAll`, the disjoint union. Duplicate rows are retained.
310unionAll
383unionAll
311− :: Query schema params columns
384+ :: Query outer commons schemas params columns
312− -> Query schema params columns
385+ -> Query outer commons schemas params columns
313− -> Query schema params columns
386+ -> Query outer commons schemas params columns
314q1 `unionAll` q2 = UnsafeQuery $
387q1 `unionAll` q2 = UnsafeQuery $
315− parenthesized (renderQuery q1)
388+ parenthesized (renderSQL q1)
316 <+> "UNION" <+> "ALL"
389 <+> "UNION" <+> "ALL"
317− <+> parenthesized (renderQuery q2)
390+ <+> parenthesized (renderSQL q2)
318
391
319-- | The results of two queries can be combined using the set operation
392-- | The results of two queries can be combined using the set operation
320-- `intersect`, the intersection. Duplicate rows are eliminated.
393-- `intersect`, the intersection. Duplicate rows are eliminated.
321intersect
394intersect
322− :: Query schema params columns
395+ :: Query outer commons schemas params columns
323− -> Query schema params columns
396+ -> Query outer commons schemas params columns
324− -> Query schema params columns
397+ -> Query outer commons schemas params columns
325q1 `intersect` q2 = UnsafeQuery $
398q1 `intersect` q2 = UnsafeQuery $
326− parenthesized (renderQuery q1)
399+ parenthesized (renderSQL q1)
327 <+> "INTERSECT"
400 <+> "INTERSECT"
328− <+> parenthesized (renderQuery q2)
401+ <+> parenthesized (renderSQL q2)
329
402
330-- | The results of two queries can be combined using the set operation
403-- | The results of two queries can be combined using the set operation
331-- `intersectAll`, the intersection. Duplicate rows are retained.
404-- `intersectAll`, the intersection. Duplicate rows are retained.
332intersectAll
405intersectAll
333− :: Query schema params columns
406+ :: Query outer commons schemas params columns
334− -> Query schema params columns
407+ -> Query outer commons schemas params columns
335− -> Query schema params columns
408+ -> Query outer commons schemas params columns
336q1 `intersectAll` q2 = UnsafeQuery $
409q1 `intersectAll` q2 = UnsafeQuery $
337− parenthesized (renderQuery q1)
410+ parenthesized (renderSQL q1)
338 <+> "INTERSECT" <+> "ALL"
411 <+> "INTERSECT" <+> "ALL"
339− <+> parenthesized (renderQuery q2)
412+ <+> parenthesized (renderSQL q2)
340
413
341-- | The results of two queries can be combined using the set operation
414-- | The results of two queries can be combined using the set operation
342-- `except`, the set difference. Duplicate rows are eliminated.
415-- `except`, the set difference. Duplicate rows are eliminated.
343except
416except
344− :: Query schema params columns
417+ :: Query outer commons schemas params columns
345− -> Query schema params columns
418+ -> Query outer commons schemas params columns
346− -> Query schema params columns
419+ -> Query outer commons schemas params columns
347q1 `except` q2 = UnsafeQuery $
420q1 `except` q2 = UnsafeQuery $
348− parenthesized (renderQuery q1)
421+ parenthesized (renderSQL q1)
349 <+> "EXCEPT"
422 <+> "EXCEPT"
350− <+> parenthesized (renderQuery q2)
423+ <+> parenthesized (renderSQL q2)
351
424
352-- | The results of two queries can be combined using the set operation
425-- | The results of two queries can be combined using the set operation
353-- `exceptAll`, the set difference. Duplicate rows are retained.
426-- `exceptAll`, the set difference. Duplicate rows are retained.
354exceptAll
427exceptAll
355− :: Query schema params columns
428+ :: Query outer commons schemas params columns
356− -> Query schema params columns
429+ -> Query outer commons schemas params columns
357− -> Query schema params columns
430+ -> Query outer commons schemas params columns
358q1 `exceptAll` q2 = UnsafeQuery $
431q1 `exceptAll` q2 = UnsafeQuery $
359− parenthesized (renderQuery q1)
432+ parenthesized (renderSQL q1)
360 <+> "EXCEPT" <+> "ALL"
433 <+> "EXCEPT" <+> "ALL"
361− <+> parenthesized (renderQuery q2)
434+ <+> parenthesized (renderSQL q2)
362
435
363{-----------------------------------------
436{-----------------------------------------
364SELECT queries
437SELECT queries
365-----------------------------------------}
438-----------------------------------------}
366
439
440+{- | The simplest kinds of `Selection` are `Star` and `DotStar` which
441+emits all columns that a `TableExpression` produces. A select `List`
442+is a list of `Expression`s. A `Selection` could be a list of
443+`WindowFunction`s `Over` `WindowDefinition`. `Additional` `Selection`s can
444+be selected with `Also`.
445+-}
446+data Selection outer commons grp schemas params from row where
447+ Star
448+ :: HasUnique tab from row
449+ => Selection outer commons 'Ungrouped schemas params from row
450+ -- ^ `HasUnique` table in the `FromClause`
451+ DotStar
452+ :: Has tab from row
453+ => Alias tab
454+ -- ^ `Has` table with `Alias`
455+ -> Selection outer commons 'Ungrouped schemas params from row
456+ List
457+ :: SListI row
458+ => NP (Aliased (Expression outer commons grp schemas params from)) row
459+ -- ^ `NP` list of `Aliased` `Expression`s
460+ -> Selection outer commons grp schemas params from row
461+ Over
462+ :: SListI row
463+ => NP (Aliased (WindowFunction outer commons grp schemas params from)) row
464+ -- ^ `NP` list of `Aliased` `WindowFunction`s
465+ -> WindowDefinition outer commons grp schemas params from
466+ -> Selection outer commons grp schemas params from row
467+ Also
468+ :: Selection outer commons grp schemas params from right
469+ -- ^ `Additional` `Selection`
470+ -> Selection outer commons grp schemas params from left
471+ -> Selection outer commons grp schemas params from (Join left right)
472+instance Additional (Selection outer commons grp schemas params from) where
473+ also = Also
474+instance (KnownSymbol col, row ~ '[col ::: ty])
475+ => Aliasable col
476+ (Expression outer commons grp schemas params from ty)
477+ (Selection outer commons grp schemas params from row) where
478+ expr `as` col = List (expr `as` col)
479+instance (Has tab (Join outer from) row0, Has col row0 ty, row1 ~ '[col ::: ty])
480+ => IsQualified tab col
481+ (Selection outer commons 'Ungrouped schemas params from row1) where
482+ tab ! col = tab ! col `as` col
483+instance
484+ ( Has tab (Join outer from) row0
485+ , Has col row0 ty
486+ , row1 ~ '[col ::: ty]
487+ , GroupedBy tab col bys )
488+ => IsQualified tab col
489+ (Selection outer commons ('Grouped bys) schemas params from row1) where
490+ tab ! col = tab ! col `as` col
491+instance (HasUnique tab (Join outer from) row0, Has col row0 ty, row1 ~ '[col ::: ty])
492+ => IsLabel col
493+ (Selection outer commons 'Ungrouped schemas params from row1) where
494+ fromLabel = fromLabel @col `as` Alias
495+instance
496+ ( HasUnique tab (Join outer from) row0
497+ , Has col row0 ty
498+ , row1 ~ '[col ::: ty]
499+ , GroupedBy tab col bys )
500+ => IsLabel col
501+ (Selection outer commons ('Grouped bys) schemas params from row1) where
502+ fromLabel = fromLabel @col `as` Alias
503+
504+instance RenderSQL (Selection outer commons grp schemas params from row) where
505+ renderSQL = \case
506+ List list -> renderCommaSeparated (renderAliased renderSQL) list
507+ Star -> "*"
508+ DotStar tab -> renderSQL tab <> ".*"
509+ Also right left -> renderSQL left <> ", " <> renderSQL right
510+ Over winFns winDef ->
511+ let
512+ renderOver
513+ :: Aliased (WindowFunction outer commons grp schemas params from) field
514+ -> ByteString
515+ renderOver (winFn `As` col) = renderSQL winFn
516+ <+> "OVER" <+> parenthesized (renderSQL winDef)
517+ <+> "AS" <+> renderSQL col
518+ in
519+ renderCommaSeparated renderOver winFns
520+
521+instance IsString
522+ (Selection outer commons grp schemas params from '["fromOnly" ::: 'NotNull 'PGtext]) where
523+ fromString str = fromString str `as` Alias
524+
367-- | the `TableExpression` in the `select` command constructs an intermediate
525-- | the `TableExpression` in the `select` command constructs an intermediate
368-- virtual table by possibly combining tables, views, eliminating rows,
526-- virtual table by possibly combining tables, views, eliminating rows,
369-- grouping, etc. This table is finally passed on to processing by
527-- grouping, etc. This table is finally passed on to processing by
370−-- the select list. The select list determines which columns of
528+-- the select list. The `Selection` determines which columns of
371-- the intermediate table are actually output.
529-- the intermediate table are actually output.
372select
530select
373− :: SListI columns
531+ :: (SListI row, row ~ (x ': xs))
374− => NP (Aliased (Expression schema relations grouping params)) (column ': columns)
532+ => Selection outer commons grp schemas params from row
375− -- ^ select list
533+ -- ^ selection
376− -> TableExpression schema params relations grouping
534+ -> TableExpression outer commons grp schemas params from
377 -- ^ intermediate virtual table
535 -- ^ intermediate virtual table
378− -> Query schema params (column ': columns)
536+ -> Query outer commons schemas params row
379−select list rels = UnsafeQuery $
537+select selection tabexpr = UnsafeQuery $
380 "SELECT"
538 "SELECT"
381− <+> renderCommaSeparated (renderAliasedAs renderExpression) list
539+ <+> renderSQL selection
382− <+> renderTableExpression rels
540+ <+> renderSQL tabexpr
541+
542+-- | Like `select` but takes an `NP` list of `Expression`s instead
543+-- of a general `Selection`.
544+select_
545+ :: (SListI row, row ~ (x ': xs))
546+ => NP (Aliased (Expression outer commons grp schemas params from)) row
547+ -- ^ select list
548+ -> TableExpression outer commons grp schemas params from
549+ -- ^ intermediate virtual table
550+ -> Query outer commons schemas params row
551+select_ = select . List
383
552
384-- | After the select list has been processed, the result table can
553-- | After the select list has been processed, the result table can
385-- be subject to the elimination of duplicate rows using `selectDistinct`.
554-- be subject to the elimination of duplicate rows using `selectDistinct`.
386selectDistinct
555selectDistinct
387− :: SListI columns
556+ :: (SListI columns, columns ~ (col ': cols))
388− => NP (Aliased (Expression schema relations 'Ungrouped params)) (column ': columns)
557+ => Selection outer commons grp schemas params from columns
389− -- ^ select list
558+ -- ^ selection
390− -> TableExpression schema params relations 'Ungrouped
559+ -> TableExpression outer commons grp schemas params from
391 -- ^ intermediate virtual table
560 -- ^ intermediate virtual table
392− -> Query schema params (column ': columns)
561+ -> Query outer commons schemas params columns
393−selectDistinct list rels = UnsafeQuery $
562+selectDistinct selection tabexpr = UnsafeQuery $
394 "SELECT DISTINCT"
563 "SELECT DISTINCT"
395− <+> renderCommaSeparated (renderAliasedAs renderExpression) list
564+ <+> renderSQL selection
396− <+> renderTableExpression rels
565+ <+> renderSQL tabexpr
397−
566+
398−-- | The simplest kind of query is `selectStar` which emits all columns
567+-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead
399−-- that the table expression produces.
568+-- of a general `Selection`.
400−selectStar
569+selectDistinct_
401− :: HasUnique relation relations columns
570+ :: (SListI columns, columns ~ (col ': cols))
402− => TableExpression schema params relations 'Ungrouped
571+ => NP (Aliased (Expression outer commons grp schemas params from)) columns
403− -- ^ intermediate virtual table
572+ -- ^ select list
404− -> Query schema params columns
573+ -> TableExpression outer commons grp schemas params from
405−selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels
406−
407−-- | A `selectDistinctStar` emits all columns that the table expression
408−-- produces and eliminates duplicate rows.
409−selectDistinctStar
410− :: HasUnique relation relations columns
411− => TableExpression schema params relations 'Ungrouped
412 -- ^ intermediate virtual table
574 -- ^ intermediate virtual table
413− -> Query schema params columns
575+ -> Query outer commons schemas params columns
414−selectDistinctStar rels = UnsafeQuery $
576+selectDistinct_ = selectDistinct . List
415− "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels
577+
416−
578+{-|
417−-- | When working with multiple tables, it can also be useful to ask
579+`selectDistinctOn` keeps only the first row of each set of rows where
418−-- for all the columns of a particular table, using `selectDotStar`.
580+the given expressions evaluate to equal. The DISTINCT ON expressions are
419−selectDotStar
581+interpreted using the same rules as for ORDER BY. ORDER BY is used to
420− :: Has relation relations columns
582+ensure that the desired row appears first.
421− => Alias relation
583+
422− -- ^ particular virtual subtable
584+The DISTINCT ON expression(s) must match the leftmost ORDER BY expression(s).
423− -> TableExpression schema params relations 'Ungrouped
585+The ORDER BY clause will normally contain additional expression(s) that
586+determine the desired precedence of rows within each DISTINCT ON group.
587+
588+In order to guarantee they match and reduce redundancy, this function
589+will prepend the The DISTINCT ON expressions to the ORDER BY clause.
590+-}
591+selectDistinctOn
592+ :: (SListI columns, columns ~ (col ': cols))
593+ => [SortExpression outer commons grp schemas params from]
594+ -- ^ DISTINCT ON expression(s) and prepended to ORDER BY clause
595+ -> Selection outer commons grp schemas params from columns
596+ -- ^ selection
597+ -> TableExpression outer commons grp schemas params from
424 -- ^ intermediate virtual table
598 -- ^ intermediate virtual table
425− -> Query schema params columns
599+ -> Query outer commons schemas params columns
426−selectDotStar rel relations = UnsafeQuery $
600+selectDistinctOn distincts selection tab = UnsafeQuery $
427− "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression relations
601+ "SELECT DISTINCT ON"
428−
602+ <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))
429−-- | A `selectDistinctDotStar` asks for all the columns of a particular table,
603+ <+> renderSQL selection
430−-- and eliminates duplicate rows.
604+ <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})
431−selectDistinctDotStar
605+ where
432− :: Has relation relations columns
606+ renderDistinctOn = \case
433− => Alias relation
607+ Asc expression -> renderSQL expression
434− -- ^ particular virtual table
608+ Desc expression -> renderSQL expression
435− -> TableExpression schema params relations 'Ungrouped
609+ AscNullsFirst expression -> renderSQL expression
610+ DescNullsFirst expression -> renderSQL expression
611+ AscNullsLast expression -> renderSQL expression
612+ DescNullsLast expression -> renderSQL expression
613+
614+-- | Like `selectDistinctOn` but takes an `NP` list of `Expression`s instead
615+-- of a general `Selection`.
616+selectDistinctOn_
617+ :: (SListI columns, columns ~ (col ': cols))
618+ => [SortExpression outer commons grp schemas params from]
619+ -- ^ distinct on and return the first row in ordering
620+ -> NP (Aliased (Expression outer commons grp schemas params from)) columns
621+ -- ^ selection
622+ -> TableExpression outer commons grp schemas params from
436 -- ^ intermediate virtual table
623 -- ^ intermediate virtual table
437− -> Query schema params columns
624+ -> Query outer commons schemas params columns
438−selectDistinctDotStar rel relations = UnsafeQuery $
625+selectDistinctOn_ distincts = selectDistinctOn distincts . List
439− "SELECT DISTINCT" <+> renderAlias rel <> ".*"
440− <+> renderTableExpression relations
441
626
442-- | `values` computes a row value or set of row values
627-- | `values` computes a row value or set of row values
443-- specified by value expressions. It is most commonly used
628-- specified by value expressions. It is most commonly used
@@ -445,16 +630,16 @@ selectDistinctDotStar rel relations = UnsafeQuery $
445-- but it can be used on its own.
630-- but it can be used on its own.
446--
631--
447-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]
632-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]
448−-- >>> let query = values (1 `As` #a :* "one" `As` #b :* Nil) [] :: Query '[] '[] Row
633+-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query outer commons schemas '[] Row
449-- >>> printSQL query
634-- >>> printSQL query
450-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")
635-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")
451values
636values
452 :: SListI cols
637 :: SListI cols
453− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols
638+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols
454− -> [NP (Aliased (Expression schema '[] 'Ungrouped params)) cols]
639+ -> [NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols]
455 -- ^ When more than one row is specified, all the rows must
640 -- ^ When more than one row is specified, all the rows must
456 -- must have the same number of elements
641 -- must have the same number of elements
457− -> Query schema params cols
642+ -> Query outer commons schemas params cols
458values rw rws = UnsafeQuery $ "SELECT * FROM"
643values rw rws = UnsafeQuery $ "SELECT * FROM"
459 <+> parenthesized (
644 <+> parenthesized (
460 "VALUES"
645 "VALUES"
@@ -465,17 +650,17 @@ values rw rws = UnsafeQuery $ "SELECT * FROM"
465 <+> parenthesized (renderCommaSeparated renderAliasPart rw)
650 <+> parenthesized (renderCommaSeparated renderAliasPart rw)
466 where
651 where
467 renderAliasPart, renderValuePart
652 renderAliasPart, renderValuePart
468− :: Aliased (Expression schema '[] 'Ungrouped params) ty -> ByteString
653+ :: Aliased (Expression outer commons 'Ungrouped schemas params '[] ) ty -> ByteString
469− renderAliasPart (_ `As` name) = renderAlias name
654+ renderAliasPart (_ `As` name) = renderSQL name
470− renderValuePart (value `As` _) = renderExpression value
655+ renderValuePart (value `As` _) = renderSQL value
471
656
472-- | `values_` computes a row value or set of row values
657-- | `values_` computes a row value or set of row values
473-- specified by value expressions.
658-- specified by value expressions.
474values_
659values_
475 :: SListI cols
660 :: SListI cols
476− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols
661+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols
477 -- ^ one row of values
662 -- ^ one row of values
478− -> Query schema params cols
663+ -> Query outer commons schemas params cols
479values_ rw = values rw []
664values_ rw = values rw []
480
665
481{-----------------------------------------
666{-----------------------------------------
@@ -489,15 +674,17 @@ Table Expressions
489-- to a table on disk, a so-called base table, but more complex expressions
674-- to a table on disk, a so-called base table, but more complex expressions
490-- can be used to modify or combine base tables in various ways.
675-- can be used to modify or combine base tables in various ways.
491data TableExpression
676data TableExpression
492− (schema :: SchemaType)
677+ (outer :: FromType)
678+ (commons :: FromType)
679+ (grp :: Grouping)
680+ (schemas :: SchemasType)
493 (params :: [NullityType])
681 (params :: [NullityType])
494− (relations :: RelationsType)
682+ (from :: FromType)
495− (grouping :: Grouping)
496 = TableExpression
683 = TableExpression
497− { fromClause :: FromClause schema params relations
684+ { fromClause :: FromClause outer commons schemas params from
498 -- ^ A table reference that can be a table name, or a derived table such
685 -- ^ A table reference that can be a table name, or a derived table such
499 -- as a subquery, a @JOIN@ construct, or complex combinations of these.
686 -- as a subquery, a @JOIN@ construct, or complex combinations of these.
500− , whereClause :: [Condition schema relations 'Ungrouped params]
687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]
501 -- ^ optional search coditions, combined with `.&&`. After the processing
688 -- ^ optional search coditions, combined with `.&&`. After the processing
502 -- of the `fromClause` is done, each row of the derived virtual table
689 -- of the `fromClause` is done, each row of the derived virtual table
503 -- is checked against the search condition. If the result of the
690 -- is checked against the search condition. If the result of the
@@ -506,20 +693,20 @@ data TableExpression
506 -- at least one column of the table generated in the `fromClause`;
693 -- at least one column of the table generated in the `fromClause`;
507 -- this is not required, but otherwise the WHERE clause will
694 -- this is not required, but otherwise the WHERE clause will
508 -- be fairly useless.
695 -- be fairly useless.
509− , groupByClause :: GroupByClause relations grouping
696+ , groupByClause :: GroupByClause grp from
510 -- ^ The `groupByClause` is used to group together those rows in a table
697 -- ^ The `groupByClause` is used to group together those rows in a table
511 -- that have the same values in all the columns listed. The order in which
698 -- that have the same values in all the columns listed. The order in which
512 -- the columns are listed does not matter. The effect is to combine each
699 -- the columns are listed does not matter. The effect is to combine each
513 -- set of rows having common values into one group row that represents all
700 -- set of rows having common values into one group row that represents all
514 -- rows in the group. This is done to eliminate redundancy in the output
701 -- rows in the group. This is done to eliminate redundancy in the output
515 -- and/or compute aggregates that apply to these groups.
702 -- and/or compute aggregates that apply to these groups.
516− , havingClause :: HavingClause schema relations grouping params
703+ , havingClause :: HavingClause outer commons grp schemas params from
517 -- ^ If a table has been grouped using `groupBy`, but only certain groups
704 -- ^ If a table has been grouped using `groupBy`, but only certain groups
518 -- are of interest, the `havingClause` can be used, much like a
705 -- are of interest, the `havingClause` can be used, much like a
519 -- `whereClause`, to eliminate groups from the result. Expressions in the
706 -- `whereClause`, to eliminate groups from the result. Expressions in the
520 -- `havingClause` can refer both to grouped expressions and to ungrouped
707 -- `havingClause` can refer both to grouped expressions and to ungrouped
521 -- expressions (which necessarily involve an aggregate function).
708 -- expressions (which necessarily involve an aggregate function).
522− , orderByClause :: [SortExpression schema relations grouping params]
709+ , orderByClause :: [SortExpression outer commons grp schemas params from]
523 -- ^ The `orderByClause` is for optional sorting. When more than one
710 -- ^ The `orderByClause` is for optional sorting. When more than one
524 -- `SortExpression` is specified, the later (right) values are used to sort
711 -- `SortExpression` is specified, the later (right) values are used to sort
525 -- rows that are equal according to the earlier (left) values.
712 -- rows that are equal according to the earlier (left) values.
@@ -529,72 +716,69 @@ data TableExpression
529 -- will be returned (but possibly fewer, if the query itself yields
716 -- will be returned (but possibly fewer, if the query itself yields
530 -- fewer rows).
717 -- fewer rows).
531 , offsetClause :: [Word64]
718 , offsetClause :: [Word64]
532− -- ^ The `offsetClause` is combined with `+` to give an offset count
719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count
533 -- if nonempty. The offset count says to skip that many rows before
720 -- if nonempty. The offset count says to skip that many rows before
534 -- beginning to return rows. The rows are skipped before the limit count
721 -- beginning to return rows. The rows are skipped before the limit count
535 -- is applied.
722 -- is applied.
536− }
723+ } deriving (GHC.Generic)
537
724
538-- | Render a `TableExpression`
725-- | Render a `TableExpression`
539−renderTableExpression
726+instance RenderSQL (TableExpression outer commons grp schemas params from) where
540− :: TableExpression schema params relations grouping
727+ renderSQL
541− -> ByteString
542−renderTableExpression
543− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat
728+ (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat
544− [ "FROM ", renderFromClause frm'
729+ [ "FROM ", renderSQL frm'
545− , renderWheres whs'
730+ , renderWheres whs'
546− , renderGroupByClause grps'
731+ , renderSQL grps'
547− , renderHavingClause hvs'
732+ , renderSQL hvs'
548− , renderOrderByClause srts'
733+ , renderOrderByClause srts'
549− , renderLimits lims'
734+ , renderLimits lims'
550− , renderOffsets offs'
735+ , renderOffsets offs' ]
551− ]
552− where
736+ where
553− renderWheres = \case
737+ renderWheres = \case
554− [] -> ""
738+ [] -> ""
555− wh:[] -> " WHERE" <+> renderExpression wh
739+ wh:[] -> " WHERE" <+> renderSQL wh
556− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)
740+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)
557− renderOrderByClause = \case
741+ renderOrderByClause = \case
558− [] -> ""
742+ [] -> ""
559− srts -> " ORDER BY"
743+ srts -> " ORDER BY"
560− <+> commaSeparated (renderSortExpression <$> srts)
744+ <+> commaSeparated (renderSQL <$> srts)
561− renderLimits = \case
745+ renderLimits = \case
562− [] -> ""
746+ [] -> ""
563− lims -> " LIMIT" <+> fromString (show (minimum lims))
747+ lims -> " LIMIT" <+> fromString (show (minimum lims))
564− renderOffsets = \case
748+ renderOffsets = \case
565− [] -> ""
749+ [] -> ""
566− offs -> " OFFSET" <+> fromString (show (sum offs))
750+ offs -> " OFFSET" <+> fromString (show (sum offs))
567
751
568-- | A `from` generates a `TableExpression` from a table reference that can be
752-- | A `from` generates a `TableExpression` from a table reference that can be
569-- a table name, or a derived table such as a subquery, a JOIN construct,
753-- a table name, or a derived table such as a subquery, a JOIN construct,
570-- or complex combinations of these. A `from` may be transformed by `where_`,
754-- or complex combinations of these. A `from` may be transformed by `where_`,
571−-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
572-- to match the left-to-right sequencing of their placement in SQL.
756-- to match the left-to-right sequencing of their placement in SQL.
573from
757from
574− :: FromClause schema params relations -- ^ table reference
758+ :: FromClause outer commons schemas params from -- ^ table reference
575− -> TableExpression schema params relations 'Ungrouped
759+ -> TableExpression outer commons 'Ungrouped schemas params from
576−from rels = TableExpression rels [] NoGroups NoHaving [] [] []
760+from tab = TableExpression tab [] noGroups NoHaving [] [] []
577
761
578-- | A `where_` is an endomorphism of `TableExpression`s which adds a
762-- | A `where_` is an endomorphism of `TableExpression`s which adds a
579-- search condition to the `whereClause`.
763-- search condition to the `whereClause`.
580where_
764where_
581− :: Condition schema relations 'Ungrouped params -- ^ filtering condition
765+ :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition
582− -> TableExpression schema params relations grouping
766+ -> TableExpression outer commons grp schemas params from
583− -> TableExpression schema params relations grouping
767+ -> TableExpression outer commons grp schemas params from
584where_ wh rels = rels {whereClause = wh : whereClause rels}
768where_ wh rels = rels {whereClause = wh : whereClause rels}
585
769
586−-- | A `group` is a transformation of `TableExpression`s which switches
770+-- | A `groupBy` is a transformation of `TableExpression`s which switches
587−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform
771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform
588-- a "grand total" aggregation query.
772-- a "grand total" aggregation query.
589−group
773+groupBy
590 :: SListI bys
774 :: SListI bys
591− => NP (By relations) bys -- ^ grouped columns
775+ => NP (By from) bys -- ^ grouped columns
592− -> TableExpression schema params relations 'Ungrouped
776+ -> TableExpression outer commons 'Ungrouped schemas params from
593− -> TableExpression schema params relations ('Grouped bys)
777+ -> TableExpression outer commons ('Grouped bys) schemas params from
594−group bys rels = TableExpression
778+groupBy bys rels = TableExpression
595 { fromClause = fromClause rels
779 { fromClause = fromClause rels
596 , whereClause = whereClause rels
780 , whereClause = whereClause rels
597− , groupByClause = Group bys
781+ , groupByClause = group bys
598 , havingClause = Having []
782 , havingClause = Having []
599 , orderByClause = []
783 , orderByClause = []
600 , limitClause = limitClause rels
784 , limitClause = limitClause rels
@@ -604,138 +788,31 @@ group bys rels = TableExpression
604-- | A `having` is an endomorphism of `TableExpression`s which adds a
788-- | A `having` is an endomorphism of `TableExpression`s which adds a
605-- search condition to the `havingClause`.
789-- search condition to the `havingClause`.
606having
790having
607− :: Condition schema relations ('Grouped bys) params -- ^ having condition
791+ :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition
608− -> TableExpression schema params relations ('Grouped bys)
792+ -> TableExpression outer commons ('Grouped bys) schemas params from
609− -> TableExpression schema params relations ('Grouped bys)
793+ -> TableExpression outer commons ('Grouped bys) schemas params from
610having hv rels = rels
794having hv rels = rels
611 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }
795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }
612
796
613−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an
797+instance OrderBy TableExpression where
614−-- ordering to the right of the `orderByClause`.
615−orderBy
616− :: [SortExpression schema relations grouping params] -- ^ sort expressions
617− -> TableExpression schema params relations grouping
618− -> TableExpression schema params relations grouping
619−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}
798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}
620
799
621-- | A `limit` is an endomorphism of `TableExpression`s which adds to the
800-- | A `limit` is an endomorphism of `TableExpression`s which adds to the
622-- `limitClause`.
801-- `limitClause`.
623limit
802limit
624 :: Word64 -- ^ limit parameter
803 :: Word64 -- ^ limit parameter
625− -> TableExpression schema params relations grouping
804+ -> TableExpression outer commons grp schemas params from
626− -> TableExpression schema params relations grouping
805+ -> TableExpression outer commons grp schemas params from
627limit lim rels = rels {limitClause = lim : limitClause rels}
806limit lim rels = rels {limitClause = lim : limitClause rels}
628
807
629-- | An `offset` is an endomorphism of `TableExpression`s which adds to the
808-- | An `offset` is an endomorphism of `TableExpression`s which adds to the
630-- `offsetClause`.
809-- `offsetClause`.
631offset
810offset
632 :: Word64 -- ^ offset parameter
811 :: Word64 -- ^ offset parameter
633− -> TableExpression schema params relations grouping
812+ -> TableExpression outer commons grp schemas params from
634− -> TableExpression schema params relations grouping
813+ -> TableExpression outer commons grp schemas params from
635offset off rels = rels {offsetClause = off : offsetClause rels}
814offset off rels = rels {offsetClause = off : offsetClause rels}
636
815
637−{-----------------------------------------
638−JSON stuff
639−-----------------------------------------}
640−
641−type PGjson_each_variant val tab =
642− '[ tab ::: '[ "key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull val ] ]
643−
644−type PGjson_each tab = PGjson_each_variant 'PGjson tab
645−type PGjsonb_each tab = PGjson_each_variant 'PGjsonb tab
646−type PGjson_each_text tab = PGjson_each_variant 'PGtext tab
647−type PGjsonb_each_text tab = PGjson_each_variant 'PGtext tab
648−
649−unsafeAliasedFromClauseExpression
650− :: Aliased (Expression schema' relations' grouping' params') ty'
651− -> FromClause schema params relations
652−unsafeAliasedFromClauseExpression aliasedExpr = UnsafeFromClause
653− (renderAliasedAs renderExpression aliasedExpr)
654−
655−-- | Expands the outermost JSON object into a set of key/value pairs.
656−jsonEach
657− :: Aliased (Expression schema relations 'Ungrouped params) '(tab, nullity 'PGjson)
658− -> FromClause schema params (PGjson_each tab)
659−jsonEach (As jexpr jname) = unsafeAliasedFromClauseExpression
660− (As (unsafeFunction "json_each" jexpr) jname)
661−
662−-- | Expands the outermost binary JSON object into a set of key/value pairs.
663−jsonbEach
664− :: Aliased (Expression schema relations 'Ungrouped params) '(tab, nullity 'PGjsonb)
665− -> FromClause schema params (PGjsonb_each tab)
666−jsonbEach (As jexpr jname) = unsafeAliasedFromClauseExpression
667− (As (unsafeFunction "jsonb_each" jexpr) jname)
668−
669−-- | Expands the outermost JSON object into a set of key/value pairs.
670−jsonEachAsText
671− :: Aliased (Expression schema relations 'Ungrouped params) '(tab, nullity 'PGjson)
672− -> FromClause schema params (PGjson_each_text tab)
673−jsonEachAsText (As jexpr jname) = unsafeAliasedFromClauseExpression
674− (As (unsafeFunction "json_each" jexpr) jname)
675−
676−-- | Expands the outermost binary JSON object into a set of key/value pairs.
677−jsonbEachAsText
678− :: Aliased (Expression schema relations 'Ungrouped params) '(tab, nullity 'PGjsonb)
679− -> FromClause schema params (PGjsonb_each_text tab)
680−jsonbEachAsText (As jexpr jname) = unsafeAliasedFromClauseExpression
681− (As (unsafeFunction "jsonb_each" jexpr) jname)
682−
683−nullRow
684− :: Has tab schema ('Table table)
685− => Alias tab
686− -> Expression schema relations grouping params
687− (nullity ('PGcomposite (RelationToRowType (TableToRelation table))))
688−nullRow tab = UnsafeExpression ("null::"<+>renderAlias tab)
689−
690−-- | Expands the JSON expression to a row whose columns match the record
691−-- type defined by the given table.
692−jsonPopulateRecordAs
693− :: (KnownSymbol alias, Has tab schema ('Table table))
694− => Alias tab
695− -> Expression schema '[] 'Ungrouped params (nullity 'PGjson)
696− -> Alias alias
697− -> FromClause schema params '[alias ::: TableToRelation table]
698−jsonPopulateRecordAs tableName expr alias = unsafeAliasedFromClauseExpression
699− (unsafeVariadicFunction "json_populate_record"
700− (nullRow tableName :* expr :* Nil) `As` alias)
701−
702−-- | Expands the binary JSON expression to a row whose columns match the record
703−-- type defined by the given table.
704−jsonbPopulateRecordAs
705− :: (KnownSymbol alias, Has tab schema ('Table table))
706− => Alias tab
707− -> Expression schema '[] 'Ungrouped params (nullity 'PGjsonb)
708− -> Alias alias
709− -> FromClause schema params '[alias ::: TableToRelation table]
710−jsonbPopulateRecordAs tableName expr alias = unsafeAliasedFromClauseExpression
711− (unsafeVariadicFunction "jsonb_populate_record"
712− (nullRow tableName :* expr :* Nil) `As` alias)
713−
714−-- | Expands the outermost array of objects in the given binary JSON expression
715−-- to a set of rows whose columns match the record type defined by the given
716−-- table.
717−jsonbPopulateRecordSetAs
718− :: (KnownSymbol alias, Has tab schema ('Table table))
719− => Alias tab
720− -> Expression schema '[] 'Ungrouped params (nullity 'PGjsonb)
721− -> Alias alias
722− -> FromClause schema params '[alias ::: TableToRelation table]
723−jsonbPopulateRecordSetAs tableName expr alias = unsafeAliasedFromClauseExpression
724− (unsafeVariadicFunction "jsonb_populate_record_set"
725− (nullRow tableName :* expr :* Nil) `As` alias)
726−
727−-- | Expands the outermost array of objects in the given JSON expression to a
728−-- set of rows whose columns match the record type defined by the given table.
729−jsonPopulateRecordSetAs
730− :: (KnownSymbol alias, Has tab schema ('Table table))
731− => Alias tab
732− -> Expression schema '[] 'Ungrouped params (nullity 'PGjson)
733− -> Alias alias
734− -> FromClause schema params '[alias ::: TableToRelation table]
735−jsonPopulateRecordSetAs tableName expr alias = unsafeAliasedFromClauseExpression
736− (unsafeVariadicFunction "json_populate_record_set"
737− (nullRow tableName :* expr :* Nil) `As` alias)
738−
739{-----------------------------------------
816{-----------------------------------------
740FROM clauses
817FROM clauses
741-----------------------------------------}
818-----------------------------------------}
@@ -744,61 +821,76 @@ FROM clauses
744A `FromClause` can be a table name, or a derived table such
821A `FromClause` can be a table name, or a derived table such
745as a subquery, a @JOIN@ construct, or complex combinations of these.
822as a subquery, a @JOIN@ construct, or complex combinations of these.
746-}
823-}
747−newtype FromClause schema params relations
824+newtype FromClause outer commons schemas params from
748 = UnsafeFromClause { renderFromClause :: ByteString }
825 = UnsafeFromClause { renderFromClause :: ByteString }
749 deriving (GHC.Generic,Show,Eq,Ord,NFData)
826 deriving (GHC.Generic,Show,Eq,Ord,NFData)
827+instance RenderSQL (FromClause outer commons schemas params from) where
828+ renderSQL = renderFromClause
750
829
751−-- | A real `table` is a table from the schema.
830+-- | A real `table` is a table from the database.
752table
831table
753− :: Has tab schema ('Table table)
832+ :: (Has sch schemas schema, Has tab schema ('Table table))
754− => Aliased Alias (alias ::: tab)
833+ => Aliased (QualifiedAlias sch) (alias ::: tab)
755− -> FromClause schema params '[alias ::: TableToRelation table]
834+ -> FromClause outer commons schemas params '[alias ::: TableToRow table]
756table (tab `As` alias) = UnsafeFromClause $
835table (tab `As` alias) = UnsafeFromClause $
757− renderAlias tab <+> "AS" <+> renderAlias alias
836+ renderSQL tab <+> "AS" <+> renderSQL alias
758
837
759-- | `subquery` derives a table from a `Query`.
838-- | `subquery` derives a table from a `Query`.
760subquery
839subquery
761− :: Aliased (Query schema params) rel
840+ :: Aliased (Query outer commons schemas params) query
762− -> FromClause schema params '[rel]
841+ -> FromClause outer commons schemas params '[query]
763−subquery = UnsafeFromClause . renderAliasedAs (parenthesized . renderQuery)
842+subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)
764
843
765-- | `view` derives a table from a `View`.
844-- | `view` derives a table from a `View`.
766view
845view
767− :: Has view schema ('View rel)
846+ :: (Has sch schemas schema, Has vw schema ('View view))
768− => Aliased Alias (alias ::: view)
847+ => Aliased (QualifiedAlias sch) (alias ::: vw)
769− -> FromClause schema params '[alias ::: rel]
848+ -> FromClause outer commons schemas params '[alias ::: view]
770view (vw `As` alias) = UnsafeFromClause $
849view (vw `As` alias) = UnsafeFromClause $
771− renderAlias vw <+> "AS" <+> renderAlias alias
850+ renderSQL vw <+> "AS" <+> renderSQL alias
851+
852+-- | `common` derives a table from a common table expression.
853+common
854+ :: Has cte commons common
855+ => Aliased Alias (alias ::: cte)
856+ -> FromClause outer commons schemas params '[alias ::: common]
857+common (cte `As` alias) = UnsafeFromClause $
858+ renderSQL cte <+> "AS" <+> renderSQL alias
772
859
860+instance Additional (FromClause outer commons schemas params) where
861+ also right left = UnsafeFromClause $
862+ renderSQL left <> ", " <> renderSQL right
863+
864+{- |
773−{- | @left & crossJoin right@. For every possible combination of rows from
865+@left & crossJoin right@. For every possible combination of rows from
774− @left@ and @right@ (i.e., a Cartesian product), the joined table will contain
866+@left@ and @right@ (i.e., a Cartesian product), the joined table will contain
775− a row consisting of all columns in @left@ followed by all columns in @right@.
867+a row consisting of all columns in @left@ followed by all columns in @right@.
776− If the tables have @n@ and @m@ rows respectively, the joined table will
868+If the tables have @n@ and @m@ rows respectively, the joined table will
777− have @n * m@ rows.
869+have @n * m@ rows.
778-}
870-}
779crossJoin
871crossJoin
780− :: FromClause schema params right
872+ :: FromClause outer commons schemas params right
781 -- ^ right
873 -- ^ right
782− -> FromClause schema params left
874+ -> FromClause outer commons schemas params left
783 -- ^ left
875 -- ^ left
784− -> FromClause schema params (Join left right)
876+ -> FromClause outer commons schemas params (Join left right)
785crossJoin right left = UnsafeFromClause $
877crossJoin right left = UnsafeFromClause $
786− renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right
878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right
787
879
788{- | @left & innerJoin right on@. The joined table is filtered by
880{- | @left & innerJoin right on@. The joined table is filtered by
789the @on@ condition.
881the @on@ condition.
790-}
882-}
791innerJoin
883innerJoin
792− :: FromClause schema params right
884+ :: FromClause outer commons schemas params right
793 -- ^ right
885 -- ^ right
794− -> Condition schema (Join left right) 'Ungrouped params
886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
795 -- ^ @on@ condition
887 -- ^ @on@ condition
796− -> FromClause schema params left
888+ -> FromClause outer commons schemas params left
797 -- ^ left
889 -- ^ left
798− -> FromClause schema params (Join left right)
890+ -> FromClause outer commons schemas params (Join left right)
799innerJoin right on left = UnsafeFromClause $
891innerJoin right on left = UnsafeFromClause $
800− renderFromClause left <+> "INNER JOIN" <+> renderFromClause right
892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right
801− <+> "ON" <+> renderExpression on
893+ <+> "ON" <+> renderSQL on
802
894
803{- | @left & leftOuterJoin right on@. First, an inner join is performed.
895{- | @left & leftOuterJoin right on@. First, an inner join is performed.
804 Then, for each row in @left@ that does not satisfy the @on@ condition with
896 Then, for each row in @left@ that does not satisfy the @on@ condition with
@@ -806,16 +898,16 @@ innerJoin right on left = UnsafeFromClause $
806 Thus, the joined table always has at least one row for each row in @left@.
898 Thus, the joined table always has at least one row for each row in @left@.
807-}
899-}
808leftOuterJoin
900leftOuterJoin
809− :: FromClause schema params right
901+ :: FromClause outer commons schemas params right
810 -- ^ right
902 -- ^ right
811− -> Condition schema (Join left right) 'Ungrouped params
903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
812 -- ^ @on@ condition
904 -- ^ @on@ condition
813− -> FromClause schema params left
905+ -> FromClause outer commons schemas params left
814 -- ^ left
906 -- ^ left
815− -> FromClause schema params (Join left (NullifyRelations right))
907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))
816leftOuterJoin right on left = UnsafeFromClause $
908leftOuterJoin right on left = UnsafeFromClause $
817− renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right
909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right
818− <+> "ON" <+> renderExpression on
910+ <+> "ON" <+> renderSQL on
819
911
820{- | @left & rightOuterJoin right on@. First, an inner join is performed.
912{- | @left & rightOuterJoin right on@. First, an inner join is performed.
821 Then, for each row in @right@ that does not satisfy the @on@ condition with
913 Then, for each row in @right@ that does not satisfy the @on@ condition with
@@ -824,16 +916,16 @@ leftOuterJoin right on left = UnsafeFromClause $
824 have a row for each row in @right@.
916 have a row for each row in @right@.
825-}
917-}
826rightOuterJoin
918rightOuterJoin
827− :: FromClause schema params right
919+ :: FromClause outer commons schemas params right
828 -- ^ right
920 -- ^ right
829− -> Condition schema (Join left right) 'Ungrouped params
921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
830 -- ^ @on@ condition
922 -- ^ @on@ condition
831− -> FromClause schema params left
923+ -> FromClause outer commons schemas params left
832 -- ^ left
924 -- ^ left
833− -> FromClause schema params (Join (NullifyRelations left) right)
925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)
834rightOuterJoin right on left = UnsafeFromClause $
926rightOuterJoin right on left = UnsafeFromClause $
835− renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right
927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right
836− <+> "ON" <+> renderExpression on
928+ <+> "ON" <+> renderSQL on
837
929
838{- | @left & fullOuterJoin right on@. First, an inner join is performed.
930{- | @left & fullOuterJoin right on@. First, an inner join is performed.
839 Then, for each row in @left@ that does not satisfy the @on@ condition with
931 Then, for each row in @left@ that does not satisfy the @on@ condition with
@@ -843,47 +935,56 @@ rightOuterJoin right on left = UnsafeFromClause $
843 is added.
935 is added.
844-}
936-}
845fullOuterJoin
937fullOuterJoin
846− :: FromClause schema params right
938+ :: FromClause outer commons schemas params right
847 -- ^ right
939 -- ^ right
848− -> Condition schema (Join left right) 'Ungrouped params
940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
849 -- ^ @on@ condition
941 -- ^ @on@ condition
850− -> FromClause schema params left
942+ -> FromClause outer commons schemas params left
851 -- ^ left
943 -- ^ left
852− -> FromClause schema params
944+ -> FromClause outer commons schemas params
853− (Join (NullifyRelations left) (NullifyRelations right))
945+ (Join (NullifyFrom left) (NullifyFrom right))
854fullOuterJoin right on left = UnsafeFromClause $
946fullOuterJoin right on left = UnsafeFromClause $
855− renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right
947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right
856− <+> "ON" <+> renderExpression on
948+ <+> "ON" <+> renderSQL on
857
949
858{-----------------------------------------
950{-----------------------------------------
859Grouping
951Grouping
860-----------------------------------------}
952-----------------------------------------}
861
953
862−-- | `By`s are used in `group` to reference a list of columns which are then
954+-- | `By`s are used in `groupBy` to reference a list of columns which are then
863-- used to group together those rows in a table that have the same values
955-- used to group together those rows in a table that have the same values
864-- in all the columns listed. @By \#col@ will reference an unambiguous
956-- in all the columns listed. @By \#col@ will reference an unambiguous
865-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
866-- qualified column @tab.col@.
958-- qualified column @tab.col@.
867data By
959data By
868− (relations :: RelationsType)
960+ (from :: FromType)
869 (by :: (Symbol,Symbol)) where
961 (by :: (Symbol,Symbol)) where
870− By
962+ By1
871− :: (HasUnique relation relations columns, Has column columns ty)
963+ :: (HasUnique table from columns, Has column columns ty)
872 => Alias column
964 => Alias column
873− -> By relations '(relation, column)
965+ -> By from '(table, column)
874 By2
966 By2
875− :: (Has relation relations columns, Has column columns ty)
967+ :: (Has table from columns, Has column columns ty)
968+ => Alias table
876− => (Alias relation, Alias column)
969+ -> Alias column
877− -> By relations '(relation, column)
970+ -> By from '(table, column)
878−deriving instance Show (By relations by)
971+deriving instance Show (By from by)
879−deriving instance Eq (By relations by)
972+deriving instance Eq (By from by)
880−deriving instance Ord (By relations by)
973+deriving instance Ord (By from by)
881−
974+instance RenderSQL (By from by) where
882−-- | Renders a `By`.
975+ renderSQL = \case
883−renderBy :: By relations by -> ByteString
884−renderBy = \case
885− By column -> renderAlias column
976+ By1 column -> renderSQL column
886− By2 (rel, column) -> renderAlias rel <> "." <> renderAlias column
977+ By2 rel column -> renderSQL rel <> "." <> renderSQL column
978+
979+instance (HasUnique rel rels cols, Has col cols ty, by ~ '(rel, col))
980+ => IsLabel col (By rels by) where fromLabel = By1 fromLabel
981+instance (HasUnique rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])
982+ => IsLabel col (NP (By rels) bys) where fromLabel = By1 fromLabel :* Nil
983+instance (Has rel rels cols, Has col cols ty, by ~ '(rel, col))
984+ => IsQualified rel col (By rels by) where (!) = By2
985+instance (Has rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])
986+ => IsQualified rel col (NP (By rels) bys) where
987+ rel ! col = By2 rel col :* Nil
887
988
888-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.
989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.
889-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
@@ -891,82 +992,107 @@ renderBy = \case
891-- done on @NoGroups@ while all output `Expression`s must be aggregated
992-- done on @NoGroups@ while all output `Expression`s must be aggregated
892-- in @Group Nil@. In general, all output `Expression`s in the
993-- in @Group Nil@. In general, all output `Expression`s in the
893-- complement of @bys@ must be aggregated in @Group bys@.
994-- complement of @bys@ must be aggregated in @Group bys@.
995+newtype GroupByClause grp from = UnsafeGroupByClause
996+ { renderGroupByClause :: ByteString }
997+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
894−data GroupByClause relations grouping where
998+instance RenderSQL (GroupByClause grp from) where
999+ renderSQL = renderGroupByClause
895− NoGroups :: GroupByClause relations 'Ungrouped
1000+noGroups :: GroupByClause 'Ungrouped from
896− Group
1001+noGroups = UnsafeGroupByClause ""
1002+group
897− :: SListI bys
1003+ :: SListI bys
898− => NP (By relations) bys
1004+ => NP (By from) bys
899− -> GroupByClause relations ('Grouped bys)
1005+ -> GroupByClause ('Grouped bys) from
900−
1006+group bys = UnsafeGroupByClause $ case bys of
901−-- | Renders a `GroupByClause`.
902−renderGroupByClause :: GroupByClause relations grouping -> ByteString
903−renderGroupByClause = \case
904− NoGroups -> ""
905− Group Nil -> ""
1007+ Nil -> ""
906− Group bys -> " GROUP BY" <+> renderCommaSeparated renderBy bys
1008+ bys' -> " GROUP BY" <+> renderCommaSeparated renderSQL bys'
907
1009
908-- | A `HavingClause` is used to eliminate groups that are not of interest.
1010-- | A `HavingClause` is used to eliminate groups that are not of interest.
909-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
1011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
910-- `TableExpression` must use `Having` whose conditions are combined with
1012-- `TableExpression` must use `Having` whose conditions are combined with
911-- `.&&`.
1013-- `.&&`.
912−data HavingClause schema relations grouping params where
1014+data HavingClause outer commons grp schemas params from where
913− NoHaving :: HavingClause schema relations 'Ungrouped params
1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from
914 Having
1016 Having
915− :: [Condition schema relations ('Grouped bys) params]
1017+ :: [Condition outer commons ('Grouped bys) schemas params from]
916− -> HavingClause schema relations ('Grouped bys) params
1018+ -> HavingClause outer commons ('Grouped bys) schemas params from
917−deriving instance Show (HavingClause schema relations grouping params)
1019+deriving instance Show (HavingClause outer commons grp schemas params from)
918−deriving instance Eq (HavingClause schema relations grouping params)
1020+deriving instance Eq (HavingClause outer commons grp schemas params from)
919−deriving instance Ord (HavingClause schema relations grouping params)
1021+deriving instance Ord (HavingClause outer commons grp schemas params from)
920
1022
921-- | Render a `HavingClause`.
1023-- | Render a `HavingClause`.
922−renderHavingClause :: HavingClause schema relations grouping params -> ByteString
1024+instance RenderSQL (HavingClause outer commons grp schemas params from) where
923−renderHavingClause = \case
1025+ renderSQL = \case
924− NoHaving -> ""
1026+ NoHaving -> ""
925− Having [] -> ""
1027+ Having [] -> ""
926− Having conditions ->
1028+ Having conditions ->
927− " HAVING" <+> commaSeparated (renderExpression <$> conditions)
1029+ " HAVING" <+> commaSeparated (renderSQL <$> conditions)
928−
1030+
929−{-----------------------------------------
1031+-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.
930−Sorting
1032+data CommonTableExpression statement
931−-----------------------------------------}
1033+ (schemas :: SchemasType)
1034+ (params :: [NullityType])
1035+ (commons0 :: FromType)
1036+ (commons1 :: FromType) where
1037+ CommonTableExpression
1038+ :: Aliased (statement commons schemas params) (cte ::: common)
1039+ -> CommonTableExpression statement schemas params commons (cte ::: common ': commons)
1040+instance
1041+ ( KnownSymbol cte
1042+ , commons1 ~ (cte ::: common ': commons)
1043+ ) => Aliasable cte
1044+ (statement commons schemas params common)
1045+ (CommonTableExpression statement schemas params commons commons1) where
1046+ statement `as` cte = CommonTableExpression (statement `as` cte)
1047+instance
1048+ ( KnownSymbol cte
1049+ , commons1 ~ (cte ::: common ': commons)
1050+ ) => Aliasable cte
1051+ (statement commons schemas params common)
1052+ (Path (CommonTableExpression statement schemas params) commons commons1) where
1053+ statement `as` cte = csingleton (statement `as` cte)
1054+
1055+instance (forall c s p r. RenderSQL (statement c s p r)) => RenderSQL
1056+ (CommonTableExpression statement schemas params commons0 commons1) where
1057+ renderSQL (CommonTableExpression (statement `As` cte)) =
1058+ renderSQL cte <+> "AS" <+> parenthesized (renderSQL statement)
1059+
1060+-- | `with` provides a way to write auxiliary statements for use in a larger query.
1061+-- These statements, referred to as `CommonTableExpression`s, can be thought of as
1062+-- defining temporary tables that exist just for one query.
1063+class With statement where
1064+ with
1065+ :: Path (CommonTableExpression statement schemas params) commons0 commons1
1066+ -- ^ common table expressions
1067+ -> statement commons1 schemas params row
1068+ -- ^ larger query
1069+ -> statement commons0 schemas params row
1070+instance With (Query outer) where
1071+ with Done query = query
1072+ with ctes query = UnsafeQuery $
1073+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL query
932
1074
933−-- | `SortExpression`s are used by `sortBy` to optionally sort the results
1075+{- |
934−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result
1076+>>> import Data.Monoid (Sum (..))
935−-- column to ascending or descending. Ascending order puts smaller values
1077+>>> import Data.Int (Int64)
936−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,
1078+>>> :{
937−-- descending order is determined with the `.>` operator. `AscNullsFirst`,
1079+ let
938−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to
1080+ query :: Query_ schema () (Sum Int64)
939−-- determine whether nulls appear before or after non-null values in the sort
1081+ query = withRecursive
940−-- ordering of a `Null` result column.
1082+ ( values_ ((1 & astype int) `as` #n)
941−data SortExpression schema relations grouping params where
1083+ `unionAll`
942− Asc
1084+ select_ ((#n + 1) `as` #n)
943− :: Expression schema relations grouping params ('NotNull ty)
1085+ (from (common #t) & where_ (#n .< 100)) `as` #t )
944− -> SortExpression schema relations grouping params
1086+ ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))
945− Desc
1087+ in printSQL query
946− :: Expression schema relations grouping params ('NotNull ty)
1088+:}
947− -> SortExpression schema relations grouping params
1089+WITH RECURSIVE "t" AS ((SELECT * FROM (VALUES ((1 :: int))) AS t ("n")) UNION ALL (SELECT ("n" + 1) AS "n" FROM "t" AS "t" WHERE ("n" < 100))) SELECT COALESCE(sum(ALL "n"), 0) AS "getSum" FROM "t" AS "t"
948− AscNullsFirst
1090+-}
949− :: Expression schema relations grouping params ('Null ty)
1091+withRecursive
950− -> SortExpression schema relations grouping params
1092+ :: Aliased (Query outer (recursive ': commons) schemas params) recursive
951− AscNullsLast
1093+ -> Query outer (recursive ': commons) schemas params row
952− :: Expression schema relations grouping params ('Null ty)
1094+ -> Query outer commons schemas params row
953− -> SortExpression schema relations grouping params
1095+withRecursive (recursive `As` cte) query = UnsafeQuery $
954− DescNullsFirst
1096+ "WITH RECURSIVE" <+> renderSQL cte
955− :: Expression schema relations grouping params ('Null ty)
1097+ <+> "AS" <+> parenthesized (renderSQL recursive)
956− -> SortExpression schema relations grouping params
1098+ <+> renderSQL query
957− DescNullsLast
958− :: Expression schema relations grouping params ('Null ty)
959− -> SortExpression schema relations grouping params
960−deriving instance Show (SortExpression schema relations grouping params)
961−
962−-- | Render a `SortExpression`.
963−renderSortExpression :: SortExpression schema relations grouping params -> ByteString
964−renderSortExpression = \case
965− Asc expression -> renderExpression expression <+> "ASC"
966− Desc expression -> renderExpression expression <+> "DESC"
967− AscNullsFirst expression -> renderExpression expression
968− <+> "ASC NULLS FIRST"
969− DescNullsFirst expression -> renderExpression expression
970− <+> "DESC NULLS FIRST"
971− AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"
972− DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"
squeal-postgresql/src/Squeal/PostgreSQL/Render.hs+66−13
@@ -9,35 +9,48 @@ Rendering helper functions.
9-}
9-}
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
12− FlexibleContexts
14+ , FlexibleContexts
15+ , LambdaCase
13 , MagicHash
16 , MagicHash
14 , OverloadedStrings
17 , OverloadedStrings
15 , PolyKinds
18 , PolyKinds
16 , RankNTypes
19 , RankNTypes
17 , ScopedTypeVariables
20 , ScopedTypeVariables
21+ , TypeApplications
18#-}
22#-}
19
23
20module Squeal.PostgreSQL.Render
24module Squeal.PostgreSQL.Render
21 ( -- * Render
25 ( -- * Render
26+ RenderSQL (..)
27+ , printSQL
28+ , escape
22− parenthesized
29+ , parenthesized
30+ , bracketed
23 , (<+>)
31 , (<+>)
24 , commaSeparated
32 , commaSeparated
25 , doubleQuoted
33 , doubleQuoted
34+ , singleQuotedText
35+ , singleQuotedUtf8
26 , renderCommaSeparated
36 , renderCommaSeparated
37+ , renderCommaSeparatedConstraint
27 , renderCommaSeparatedMaybe
38 , renderCommaSeparatedMaybe
28 , renderNat
39 , renderNat
29− , RenderSQL (..)
40+ , renderSymbol
30− , printSQL
31 ) where
41 ) where
32
42
33−import Control.Monad.Base
43+import Control.Monad.IO.Class (MonadIO (..))
34import Data.ByteString (ByteString)
44import Data.ByteString (ByteString)
35−import Data.Maybe
45+import Data.Maybe (catMaybes)
36import Data.Monoid ((<>))
46import Data.Monoid ((<>))
47+import Data.Text (Text)
37import Generics.SOP
48import Generics.SOP
38import GHC.Exts
49import GHC.Exts
39−import GHC.TypeLits
50+import GHC.TypeLits hiding (Text)
40
51
52+import qualified Data.Text as Text
53+import qualified Data.Text.Encoding as Text
41import qualified Data.ByteString as ByteString
54import qualified Data.ByteString as ByteString
42import qualified Data.ByteString.Char8 as Char8
55import qualified Data.ByteString.Char8 as Char8
43
56
@@ -45,8 +58,13 @@ import qualified Data.ByteString.Char8 as Char8
45parenthesized :: ByteString -> ByteString
58parenthesized :: ByteString -> ByteString
46parenthesized str = "(" <> str <> ")"
59parenthesized str = "(" <> str <> ")"
47
60
61+-- | Square bracket a `ByteString`
62+bracketed :: ByteString -> ByteString
63+bracketed str = "[" <> str <> "]"
64+
48-- | Concatenate two `ByteString`s with a space between.
65-- | Concatenate two `ByteString`s with a space between.
49(<+>) :: ByteString -> ByteString -> ByteString
66(<+>) :: ByteString -> ByteString -> ByteString
67+infixr 7 <+>
50str1 <+> str2 = str1 <> " " <> str2
68str1 <+> str2 = str1 <> " " <> str2
51
69
52-- | Comma separate a list of `ByteString`s.
70-- | Comma separate a list of `ByteString`s.
@@ -57,6 +75,15 @@ commaSeparated = ByteString.intercalate ", "
57doubleQuoted :: ByteString -> ByteString
75doubleQuoted :: ByteString -> ByteString
58doubleQuoted str = "\"" <> str <> "\""
76doubleQuoted str = "\"" <> str <> "\""
59
77
78+-- | Add single quotes around a `Text` and escape single quotes within it.
79+singleQuotedText :: Text -> ByteString
80+singleQuotedText str =
81+ "'" <> Text.encodeUtf8 (Text.replace "'" "''" str) <> "'"
82+
83+-- | Add single quotes around a `ByteString` and escape single quotes within it.
84+singleQuotedUtf8 :: ByteString -> ByteString
85+singleQuotedUtf8 = singleQuotedText . Text.decodeUtf8
86+
60-- | Comma separate the renderings of a heterogeneous list.
87-- | Comma separate the renderings of a heterogeneous list.
61renderCommaSeparated
88renderCommaSeparated
62 :: SListI xs
89 :: SListI xs
@@ -67,6 +94,16 @@ renderCommaSeparated render
67 . hcollapse
94 . hcollapse
68 . hmap (K . render)
95 . hmap (K . render)
69
96
97+-- | Comma separate the renderings of a heterogeneous list.
98+renderCommaSeparatedConstraint
99+ :: forall c xs expression. (All c xs, SListI xs)
100+ => (forall x. c x => expression x -> ByteString)
101+ -> NP expression xs -> ByteString
102+renderCommaSeparatedConstraint render
103+ = commaSeparated
104+ . hcollapse
105+ . hcmap (Proxy @c) (K . render)
106+
70-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping
107-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping
71-- `Nothing`s.
108-- `Nothing`s.
72renderCommaSeparatedMaybe
109renderCommaSeparatedMaybe
@@ -80,13 +117,29 @@ renderCommaSeparatedMaybe render
80 . hmap (K . render)
117 . hmap (K . render)
81
118
82-- | Render a promoted `Nat`.
119-- | Render a promoted `Nat`.
83−renderNat :: KnownNat n => proxy n -> ByteString
120+renderNat :: forall n. KnownNat n => ByteString
84−renderNat (_ :: proxy n) = fromString (show (natVal' (proxy# :: Proxy# n)))
121+renderNat = fromString (show (natVal' (proxy# :: Proxy# n)))
122+
123+-- | Render a promoted `Symbol`.
124+renderSymbol :: forall s. KnownSymbol s => ByteString
125+renderSymbol = fromString (symbolVal' (proxy# :: Proxy# s))
85
126
86-- | A class for rendering SQL
127-- | A class for rendering SQL
87−class RenderSQL sql where
128+class RenderSQL sql where renderSQL :: sql -> ByteString
88− renderSQL :: sql -> ByteString
89
129
90-- | Print SQL.
130-- | Print SQL.
91−printSQL :: (RenderSQL sql, MonadBase IO io) => sql -> io ()
131+printSQL :: (RenderSQL sql, MonadIO io) => sql -> io ()
92−printSQL = liftBase . Char8.putStrLn . renderSQL
132+printSQL = liftIO . Char8.putStrLn . renderSQL
133+
134+-- | `escape` a character to prevent injection
135+escape :: Char -> String
136+escape = \case
137+ '\NUL' -> "\\0"
138+ '\'' -> "''"
139+ '"' -> "\\\""
140+ '\b' -> "\\b"
141+ '\n' -> "\\n"
142+ '\r' -> "\\r"
143+ '\t' -> "\\t"
144+ '\\' -> "\\\\"
145+ c -> [c]
squeal-postgresql/src/Squeal/PostgreSQL/Schema.hs+314−617
@@ -1,16 +1,15 @@
1{-|
1{-|
2Module: Squeal.PostgreSQL.Schema
2Module: Squeal.PostgreSQL.Schema
3Description: Embedding of PostgreSQL type and alias system
3Description: Embedding of PostgreSQL type and alias system
4−Copyright: (c) Eitan Chatav, 2017
4+Copyright: (c) Eitan Chatav, 2019
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
8−This module provides a type-level DSL for kinds of Postgres types,
8+`Squeal.PostgreSQL.Schema` provides a type-level DSL for kinds of Postgres types,
9tables, schema, constraints, aliases, enumerated labels, and groupings.
9tables, schema, constraints, aliases, enumerated labels, and groupings.
10It also defines useful type families to operate on these. Finally,
10It also defines useful type families to operate on these. Finally,
11it defines an embedding of Haskell types into Postgres types.
11it defines an embedding of Haskell types into Postgres types.
12-}
12-}
13−{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-}
14{-# LANGUAGE
13{-# LANGUAGE
15 AllowAmbiguousTypes
14 AllowAmbiguousTypes
16 , ConstraintKinds
15 , ConstraintKinds
@@ -20,7 +19,9 @@ it defines an embedding of Haskell types into Postgres types.
20 , FlexibleInstances
19 , FlexibleInstances
21 , FunctionalDependencies
20 , FunctionalDependencies
22 , GADTs
21 , GADTs
22+ , LambdaCase
23 , OverloadedStrings
23 , OverloadedStrings
24+ , QuantifiedConstraints
24 , RankNTypes
25 , RankNTypes
25 , ScopedTypeVariables
26 , ScopedTypeVariables
26 , StandaloneDeriving
27 , StandaloneDeriving
@@ -33,130 +34,85 @@ it defines an embedding of Haskell types into Postgres types.
33#-}
34#-}
34
35
35module Squeal.PostgreSQL.Schema
36module Squeal.PostgreSQL.Schema
36− ( -- * Types
37+ ( -- * Postgres Types
37 PGType (..)
38 PGType (..)
38− , HasOid (..)
39 , NullityType (..)
39 , NullityType (..)
40+ , RowType
41+ , FromType
42+ -- * Schema Types
40 , ColumnType
43 , ColumnType
41− -- * Tables
42 , ColumnsType
44 , ColumnsType
43− , RelationType
44− , NilRelation
45− , RelationsType
46 , TableType
45 , TableType
47− -- * Schema
48 , SchemumType (..)
46 , SchemumType (..)
47+ , IndexType (..)
48+ , FunctionType
49+ , OperatorType (..)
50+ , ReturnsType (..)
49 , SchemaType
51 , SchemaType
52+ , SchemasType
53+ , Public
50 -- * Constraints
54 -- * Constraints
51 , (:=>)
55 , (:=>)
52 , ColumnConstraint (..)
56 , ColumnConstraint (..)
53 , TableConstraint (..)
57 , TableConstraint (..)
54 , TableConstraints
58 , TableConstraints
55− , NilTableConstraints
56 , Uniquely
59 , Uniquely
57− -- * Aliases
58− , (:::)
59− , Alias (Alias)
60− , renderAlias
61− , renderAliases
62− , Aliased (As)
63− , renderAliasedAs
64− , AliasesOf
65− , ZipAliased (..)
66− , Has
67− , HasUnique
68− , HasAll
69− , IsLabel (..)
70− , IsQualified (..)
71 -- * Enumerated Labels
60 -- * Enumerated Labels
72 , IsPGlabel (..)
61 , IsPGlabel (..)
73 , PGlabel (..)
62 , PGlabel (..)
74− , renderLabel
63+ -- * Data Definitions
75− , renderLabels
76− -- * Grouping
77− , Grouping (..)
78− , GroupedBy
79− -- * Type Families
80− , Join
81− , With
82 , Create
64 , Create
65+ , CreateIfNotExists
66+ , CreateOrReplace
83 , Drop
67 , Drop
68+ , DropSchemum
69+ , DropIfExists
70+ , DropSchemumIfExists
84 , Alter
71 , Alter
72+ , AlterIfExists
85 , Rename
73 , Rename
86− , Elem
74+ , RenameIfExists
87− , In
75+ , ConstraintInvolves
76+ , DropIfConstraintsInvolve
77+ , IsNotElem
78+ , AllUnique
79+ -- * Type Classifications
88 , PGNum
80 , PGNum
89 , PGIntegral
81 , PGIntegral
90 , PGFloating
82 , PGFloating
91 , PGTypeOf
83 , PGTypeOf
92− , PGarrayOf
84+ , PGJsonType
93− , PGarray
85+ , PGJsonKey
94− , PGtextArray
95− , PGobjectpairs
96− , SameTypes
97 , SamePGType
86 , SamePGType
98 , AllNotNull
87 , AllNotNull
99 , NotAllNull
88 , NotAllNull
89+ -- * Nullifications
100 , NullifyType
90 , NullifyType
101− , NullifyRelation
91+ , NullifyRow
102− , NullifyRelations
92+ , NullifyFrom
103− , ColumnsToRelation
93+ -- * Table Conversions
104 , TableToColumns
94 , TableToColumns
105− , TableToRelation
95+ , ColumnsToRow
106− , RelationToRowType
96+ , TableToRow
107− , ConstraintInvolves
108− , DropIfConstraintsInvolve
109− -- ** JSON support
110− , PGjson_
111− , PGjsonKey
112− -- * Embedding
113− , PG
114− , EnumFrom
115− , LabelsFrom
116− , CompositeFrom
117− , FieldNamesFrom
118− , FieldTypesFrom
119− , ConstructorsOf
120− , ConstructorNameOf
121− , ConstructorNamesOf
122− , FieldsOf
123− , FieldNameOf
124− , FieldNamesOf
125− , FieldTypeOf
126− , FieldTypesOf
127− , RecordCodeOf
128− , MapMaybes (..)
129− , Nulls
130 ) where
97 ) where
131
98
132−import Control.DeepSeq
99+import Control.Category
133−import Data.Aeson (Value)
134−import Data.ByteString (ByteString)
135−import Data.Int (Int16, Int32, Int64)
136import Data.Kind
100import Data.Kind
137import Data.Monoid hiding (All)
101import Data.Monoid hiding (All)
138−import Data.Scientific (Scientific)
139−import Data.String
140−import Data.Text (Text)
141−import Data.Time
142−import Data.Word (Word16, Word32, Word64)
143import Data.Type.Bool
102import Data.Type.Bool
144−import Data.UUID.Types (UUID)
145import Generics.SOP
103import Generics.SOP
146−import GHC.OverloadedLabels
147import GHC.TypeLits
104import GHC.TypeLits
148−import Network.IP.Addr
105+import Prelude hiding (id, (.))
149−
150−import qualified Data.ByteString.Lazy as Lazy
151−import qualified Data.Text.Lazy as Lazy
152−import qualified GHC.Generics as GHC
153−import qualified Generics.SOP.Type.Metadata as Type
154
106
107+import Squeal.PostgreSQL.Alias
108+import Squeal.PostgreSQL.List
155import Squeal.PostgreSQL.Render
109import Squeal.PostgreSQL.Render
156
110
111+-- $setup
112+-- >>> import Squeal.PostgreSQL
113+
157-- | `PGType` is the promoted datakind of PostgreSQL types.
114-- | `PGType` is the promoted datakind of PostgreSQL types.
158--
115--
159−-- >>> import Squeal.PostgreSQL.Schema
160-- >>> :kind 'PGbool
116-- >>> :kind 'PGbool
161-- 'PGbool :: PGType
117-- 'PGbool :: PGType
162data PGType
118data PGType
@@ -167,6 +123,7 @@ data PGType
167 | PGnumeric -- ^ arbitrary precision numeric type
123 | PGnumeric -- ^ arbitrary precision numeric type
168 | PGfloat4 -- ^ single precision floating-point number (4 bytes)
124 | PGfloat4 -- ^ single precision floating-point number (4 bytes)
169 | PGfloat8 -- ^ double precision floating-point number (8 bytes)
125 | PGfloat8 -- ^ double precision floating-point number (8 bytes)
126+ | PGmoney -- ^ currency amount
170 | PGchar Nat -- ^ fixed-length character string
127 | PGchar Nat -- ^ fixed-length character string
171 | PGvarchar Nat -- ^ variable-length character string
128 | PGvarchar Nat -- ^ variable-length character string
172 | PGtext -- ^ variable-length character string
129 | PGtext -- ^ variable-length character string
@@ -181,40 +138,16 @@ data PGType
181 | PGinet -- ^ IPv4 or IPv6 host address
138 | PGinet -- ^ IPv4 or IPv6 host address
182 | PGjson -- ^ textual JSON data
139 | PGjson -- ^ textual JSON data
183 | PGjsonb -- ^ binary JSON data, decomposed
140 | PGjsonb -- ^ binary JSON data, decomposed
184− | PGvararray PGType -- ^ variable length array
141+ | PGvararray NullityType -- ^ variable length array
185− | PGfixarray Nat PGType -- ^ fixed length array
142+ | PGfixarray [Nat] NullityType -- ^ fixed length array
186− | PGenum [Symbol]
143+ | PGenum [Symbol] -- ^ enumerated (enum) types are data types that comprise a static, ordered set of values.
187− | PGcomposite [(Symbol, PGType)]
144+ | PGcomposite RowType -- ^ a composite type represents the structure of a row or record; it is essentially just a list of field names and their data types.
145+ | PGtsvector -- ^ A tsvector value is a sorted list of distinct lexemes, which are words that have been normalized to merge different variants of the same word.
146+ | PGtsquery -- ^ A tsquery value stores lexemes that are to be searched for.
147+ | PGoid -- Object identifiers (OIDs) are used internally by PostgreSQL as primary keys for various system tables.
148+ | PGrange PGType -- ^ Range types are data types representing a range of values of some element type (called the range's subtype).
188 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types
149 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types
189
150
190−-- | The object identifier of a `PGType`.
191−--
192−-- >>> :set -XTypeApplications
193−-- >>> oid @'PGbool
194−-- 16
195−class HasOid (ty :: PGType) where oid :: Word32
196−instance HasOid 'PGbool where oid = 16
197−instance HasOid 'PGint2 where oid = 21
198−instance HasOid 'PGint4 where oid = 23
199−instance HasOid 'PGint8 where oid = 20
200−instance HasOid 'PGnumeric where oid = 1700
201−instance HasOid 'PGfloat4 where oid = 700
202−instance HasOid 'PGfloat8 where oid = 701
203−instance HasOid ('PGchar n) where oid = 18
204−instance HasOid ('PGvarchar n) where oid = 1043
205−instance HasOid 'PGtext where oid = 25
206−instance HasOid 'PGbytea where oid = 17
207−instance HasOid 'PGtimestamp where oid = 1114
208−instance HasOid 'PGtimestamptz where oid = 1184
209−instance HasOid 'PGdate where oid = 1082
210−instance HasOid 'PGtime where oid = 1083
211−instance HasOid 'PGtimetz where oid = 1266
212−instance HasOid 'PGinterval where oid = 1186
213−instance HasOid 'PGuuid where oid = 2950
214−instance HasOid 'PGinet where oid = 869
215−instance HasOid 'PGjson where oid = 114
216−instance HasOid 'PGjsonb where oid = 3802
217−
218-- | `NullityType` encodes the potential presence or definite absence of a
151-- | `NullityType` encodes the potential presence or definite absence of a
219-- @NULL@ allowing operations which are sensitive to such to be well typed.
152-- @NULL@ allowing operations which are sensitive to such to be well typed.
220--
153--
@@ -233,11 +166,6 @@ data NullityType
233type (:=>) constraint ty = '(constraint,ty)
166type (:=>) constraint ty = '(constraint,ty)
234infixr 7 :=>
167infixr 7 :=>
235
168
236−-- | The alias operator `:::` is like a promoted version of `As`,
237−-- a type level pair between an alias and some type.
238−type (:::) (alias :: Symbol) ty = '(alias,ty)
239−infixr 6 :::
240−
241-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.
169-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.
242-- A column can be assigned a default value.
170-- A column can be assigned a default value.
243-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also
171-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also
@@ -279,11 +207,14 @@ data TableConstraint
279 | PrimaryKey [Symbol]
207 | PrimaryKey [Symbol]
280 | ForeignKey [Symbol] Symbol [Symbol]
208 | ForeignKey [Symbol] Symbol [Symbol]
281
209
282−-- | A `TableConstraints` is a row of `TableConstraint`s.
210+{- | A `TableConstraints` is a row of `TableConstraint`s.
211+
212+>>> :{
213+type family UsersConstraints :: TableConstraints where
214+ UsersConstraints = '[ "pk_users" ::: 'PrimaryKey '["id"] ]
215+:}
216+-}
283type TableConstraints = [(Symbol,TableConstraint)]
217type TableConstraints = [(Symbol,TableConstraint)]
284−-- | A monokinded empty `TableConstraints`.
285−type family NilTableConstraints :: TableConstraints where
286− NilTableConstraints = '[]
287
218
288-- | A `ForeignKey` must reference columns that either are
219-- | A `ForeignKey` must reference columns that either are
289-- a `PrimaryKey` or form a `Unique` constraint.
220-- a `PrimaryKey` or form a `Unique` constraint.
@@ -307,265 +238,64 @@ type family Uniquely
307-- :}
238-- :}
308type TableType = (TableConstraints,ColumnsType)
239type TableType = (TableConstraints,ColumnsType)
309
240
310−-- | `RelationType` is a row of `NullityType`
241+{- | A `RowType` is a row of `NullityType`. They correspond to Haskell
311−--
242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.
243+
312−-- >>> :{
244+>>> :{
313−-- type family PersonRelation :: RelationType where
245+type family PersonRow :: RowType where
314−-- PersonRelation =
246+ PersonRow =
315−-- '[ "name" ::: 'NotNull 'PGtext
247+ '[ "name" ::: 'NotNull 'PGtext
316−-- , "age" ::: 'NotNull 'PGint4
248+ , "age" ::: 'NotNull 'PGint4
317−-- , "dateOfBirth" ::: 'Null 'PGdate
249+ , "dateOfBirth" ::: 'Null 'PGdate
318−-- ]
250+ ]
319−-- :}
251+:}
320−type RelationType = [(Symbol,NullityType)]
252+-}
321−-- | A monokinded empty `RelationType`.
253+type RowType = [(Symbol,NullityType)]
322−type family NilRelation :: RelationType where NilRelation = '[]
323−
324−-- | `RelationsType` is a row of `RelationType`s, thought of as a product.
325−type RelationsType = [(Symbol,RelationType)]
326
254
255+{- | `FromType` is a row of `RowType`s. It can be thought of as
256+a product, or horizontal gluing and is used in `Squeal.PostgreSQL.Query.FromClause`s
257+and `Squeal.PostgreSQL.Query.TableExpression`s.
258+-}
259+type FromType = [(Symbol,RowType)]
260+
327−-- | `ColumnsToRelation` removes column constraints.
261+-- | `ColumnsToRow` removes column constraints.
328−type family ColumnsToRelation (columns :: ColumnsType) :: RelationType where
262+type family ColumnsToRow (columns :: ColumnsType) :: RowType where
329− ColumnsToRelation '[] = '[]
263+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': column5 ::: _ :=> ty5 ': columns) =
330− ColumnsToRelation (column ::: constraint :=> ty ': columns) =
264+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': ColumnsToRow columns
331− column ::: ty ': ColumnsToRelation columns
265+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': columns) =
266+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': ColumnsToRow columns
267+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': columns) =
268+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': ColumnsToRow columns
269+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': columns) =
270+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': ColumnsToRow columns
271+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': columns) =
272+ column ::: ty ': column1 ::: ty1 ': ColumnsToRow columns
273+ ColumnsToRow (column ::: _ :=> ty ': columns) =
274+ column ::: ty ': ColumnsToRow columns
275+ ColumnsToRow '[] = '[]
332
276
333-- | `TableToColumns` removes table constraints.
277-- | `TableToColumns` removes table constraints.
334type family TableToColumns (table :: TableType) :: ColumnsType where
278type family TableToColumns (table :: TableType) :: ColumnsType where
335 TableToColumns (constraints :=> columns) = columns
279 TableToColumns (constraints :=> columns) = columns
336
280
337−-- | Convert a table to a relation.
281+-- | Convert a table to a row type.
338−type family TableToRelation (table :: TableType) :: RelationType where
282+type family TableToRow (table :: TableType) :: RowType where
339− TableToRelation tab = ColumnsToRelation (TableToColumns tab)
283+ TableToRow tab = ColumnsToRow (TableToColumns tab)
340
284
341−-- | `Grouping` is an auxiliary namespace, created by
285+-- | Numeric Postgres types.
342−-- @GROUP BY@ clauses (`Squeal.PostgreSQL.Query.group`), and used
286+type PGNum =
343−-- for typesafe aggregation
287+ '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]
344−data Grouping
345− = Ungrouped -- ^ no aggregation permitted
346− | Grouped [(Symbol,Symbol)] -- ^ aggregation required for any column which is not grouped
347
288
348−{- | A `GroupedBy` constraint indicates that a table qualified column is
289+-- | Floating Postgres types.
349−a member of the auxiliary namespace created by @GROUP BY@ clauses and thus,
350−may be called in an output `Squeal.PostgreSQL.Expression.Expression` without aggregating.
351−-}
352−class (KnownSymbol relation, KnownSymbol column)
353− => GroupedBy relation column bys where
354−instance {-# OVERLAPPING #-} (KnownSymbol relation, KnownSymbol column)
355− => GroupedBy relation column ('(table,column) ': bys)
356−instance {-# OVERLAPPABLE #-}
357− ( KnownSymbol relation
358− , KnownSymbol column
359− , GroupedBy relation column bys
360− ) => GroupedBy relation column (tabcol ': bys)
361−
362−-- | `Alias`es are proxies for a type level string or `Symbol`
363−-- and have an `IsLabel` instance so that with @-XOverloadedLabels@
364−--
365−-- >>> :set -XOverloadedLabels
366−-- >>> #foobar :: Alias "foobar"
367−-- Alias
368−data Alias (alias :: Symbol) = Alias
369− deriving (Eq,GHC.Generic,Ord,Show,NFData)
370−instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where
371− fromLabel = Alias
372−instance aliases ~ '[alias] => IsLabel alias (NP Alias aliases) where
373− fromLabel = fromLabel :* Nil
374−instance KnownSymbol alias => RenderSQL (Alias alias) where renderSQL = renderAlias
375−
376−-- | >>> renderAlias #jimbob
377−-- "\"jimbob\""
378−renderAlias :: KnownSymbol alias => Alias alias -> ByteString
379−renderAlias = doubleQuoted . fromString . symbolVal
380−
381−-- | >>> import Generics.SOP (NP(..))
382−-- >>> renderAliases (#jimbob :* #kandi :* Nil)
383−-- ["\"jimbob\"","\"kandi\""]
384−renderAliases
385− :: All KnownSymbol aliases => NP Alias aliases -> [ByteString]
386−renderAliases = hcollapse
387− . hcmap (Proxy @KnownSymbol) (K . renderAlias)
388−
389−-- | The `As` operator is used to name an expression. `As` is like a demoted
390−-- version of `:::`.
391−--
392−-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)
393−-- As (Just "hello") Alias
394−data Aliased expression aliased where
395− As
396− :: KnownSymbol alias
397− => expression ty
398− -> Alias alias
399− -> Aliased expression (alias ::: ty)
400−deriving instance Show (expression ty)
401− => Show (Aliased expression (alias ::: ty))
402−deriving instance Eq (expression ty)
403− => Eq (Aliased expression (alias ::: ty))
404−deriving instance Ord (expression ty)
405− => Ord (Aliased expression (alias ::: ty))
406−instance (alias0 ~ alias1, alias0 ~ alias2, KnownSymbol alias2)
407− => IsLabel alias0 (Aliased Alias (alias1 ::: alias2)) where
408− fromLabel = fromLabel @alias2 `As` fromLabel @alias1
409−
410−-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")
411−-- >>> renderAliasedAs renderMaybe (Just (3::Int) `As` #an_int)
412−-- "Just AS \"an_int\""
413−renderAliasedAs
414− :: (forall ty. expression ty -> ByteString)
415− -> Aliased expression aliased
416− -> ByteString
417−renderAliasedAs render (expression `As` alias) =
418− render expression <> " AS " <> renderAlias alias
419−
420−-- | `AliasesOf` retains the AliasesOf in a row.
421−type family AliasesOf aliaseds where
422− AliasesOf '[] = '[]
423− AliasesOf (alias ::: ty ': tys) = alias ': AliasesOf tys
424−
425−-- | The `ZipAliased` class provides a type family for zipping
426−-- `Symbol` lists together with arbitrary lists of the same size,
427−-- with an associated type family `ZipAs`, together with
428−-- a method `zipAs` for zipping heterogeneous lists of `Alias`es
429−-- together with a heterogeneous list of expressions into
430−-- a heterogeneous list of `Aliased` expressions.
431−class
432− ( SListI (ZipAs ns xs)
433− , All KnownSymbol ns
434− ) => ZipAliased ns xs where
435−
436− type family ZipAs
437− (ns :: [Symbol]) (xs :: [k]) = (zs :: [(Symbol,k)]) | zs -> ns xs
438−
439− zipAs
440− :: NP Alias ns
441− -> NP expr xs
442− -> NP (Aliased expr) (ZipAs ns xs)
443−
444−instance ZipAliased '[] '[] where
445− type ZipAs '[] '[] = '[]
446− zipAs Nil Nil = Nil
447−
448−instance
449− ( KnownSymbol n
450− , ZipAliased ns xs
451− ) => ZipAliased (n ': ns) (x ': xs) where
452− type ZipAs (n ': ns) (x ': xs) = '(n,x) ': ZipAs ns xs
453− zipAs (n :* ns) (x :* xs) = x `As` n :* zipAs ns xs
454−
455−-- | @HasUnique alias fields field@ is a constraint that proves that
456−-- @fields@ is a singleton of @alias ::: field@.
457−type HasUnique alias fields field = fields ~ '[alias ::: field]
458−
459−-- | @Has alias fields field@ is a constraint that proves that
460−-- @fields@ has a field of @alias ::: field@, inferring @field@
461−-- from @alias@ and @fields@.
462−class KnownSymbol alias =>
463− Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)
464− | alias fields -> field where
465−instance {-# OVERLAPPING #-} KnownSymbol alias
466− => Has alias (alias ::: field ': fields) field
467−instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)
468− => Has alias (field' ': fields) field
469−
470−-- | `HasAll` extends `Has` to take lists of @aliases@ and @fields@ and infer
471−-- a list of @subfields@.
472−class
473− ( All KnownSymbol aliases
474− ) => HasAll
475− (aliases :: [Symbol])
476− (fields :: [(Symbol,kind)])
477− (subfields :: [(Symbol,kind)])
478− | aliases fields -> subfields where
479−instance {-# OVERLAPPING #-} HasAll '[] fields '[]
480−instance {-# OVERLAPPABLE #-}
481− (Has alias fields field, HasAll aliases fields subfields)
482− => HasAll (alias ': aliases) fields (alias ::: field ': subfields)
483−
484−-- | Analagous to `IsLabel`, the constraint
485−-- `IsQualified` defines `!` for a column alias qualified
486−-- by a table alias.
487−class IsQualified table column expression where
488− (!) :: Alias table -> Alias column -> expression
489− infixl 9 !
490−instance IsQualified table column (Alias table, Alias column) where (!) = (,)
491−
492−-- | @Elem@ is a promoted `Data.List.elem`.
493−type family Elem x xs where
494− Elem x '[] = 'False
495− Elem x (x ': xs) = 'True
496− Elem x (_ ': xs) = Elem x xs
497−
498−-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.
499−type family In x xs :: Constraint where In x xs = Elem x xs ~ 'True
500−
501−-- | `PGNum` is a constraint on `PGType` whose
502−-- `Squeal.PostgreSQL.Expression.Expression`s have a `Num` constraint.
503−type PGNum ty =
504− In ty '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]
505−
506−-- | `PGFloating` is a constraint on `PGType` whose
507−-- `Squeal.PostgreSQL.Expression.Expression`s
508−-- have `Fractional` and `Floating` constraints.
509−type PGFloating ty = In ty '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]
290+type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]
510−
291+
511−-- | `PGIntegral` is a constraint on `PGType` whose
292+-- | Integral Postgres types.
512−-- `Squeal.PostgreSQL.Expression.Expression`s
513−-- have `Squeal.PostgreSQL.Expression.div_` and
514−-- `Squeal.PostgreSQL.Expression.mod_` functions.
515−type PGIntegral ty = In ty '[ 'PGint2, 'PGint4, 'PGint8]
293+type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]
516−
517−-- | Error message helper for displaying unavailable\/unknown\/placeholder type
518−-- variables whose kind is known.
519−type Placeholder k = 'Text "(_::" :<>: 'ShowType k :<>: 'Text ")"
520−
521−type ErrArrayOf arr ty = arr :<>: 'Text " " :<>: ty
522−type ErrPGfixarrayOf t = ErrArrayOf ('ShowType 'PGfixarray :<>: 'Text " " :<>: Placeholder Nat) t
523−type ErrPGvararrayOf t = ErrArrayOf ('ShowType 'PGvararray) t
524−
525−-- | Ensure a type is a valid array type.
526−type family PGarray name arr :: Constraint where
527− PGarray name ('PGvararray x) = ()
528− PGarray name ('PGfixarray n x) = ()
529− PGarray name val = TypeError
530− ('Text name :<>: 'Text ": Unsatisfied PGarray constraint. Expected either: "
531− :$$: 'Text " • " :<>: ErrPGvararrayOf (Placeholder PGType)
532− :$$: 'Text " • " :<>: ErrPGfixarrayOf (Placeholder PGType)
533− :$$: 'Text "But got: " :<>: 'ShowType val)
534−
535−-- | Ensure a type is a valid array type with a specific element type.
536−type family PGarrayOf name arr ty :: Constraint where
537− PGarrayOf name ('PGvararray x) ty = x ~ ty
538− PGarrayOf name ('PGfixarray n x) ty = x ~ ty
539− PGarrayOf name val ty = TypeError
540− ( 'Text name :<>: 'Text "Unsatisfied PGarrayOf constraint. Expected either: "
541− :$$: 'Text " • " :<>: ErrPGvararrayOf ( 'ShowType ty )
542− :$$: 'Text " • " :<>: ErrPGfixarrayOf ( 'ShowType ty )
543− :$$: 'Text "But got: " :<>: 'ShowType val)
544−
545−-- | Ensure a type is a valid array type whose elements are text.
546−type PGtextArray name arr = PGarrayOf name arr 'PGtext
547−
548−-- | Ensure a list of arguments is an alternating list of text and value pairs.
549−type family PGobjectpairs name x :: Constraint where
550− PGobjectpairs name ('NotNull 'PGtext : arg : xs) = PGobjectpairs name xs
551− PGobjectpairs name '[] = ()
552− PGobjectpairs name (x:xs) = TypeError
553− ( 'Text name :<>: 'Text ": Incorrect argument list:"
554− :$$: 'Text "Expected alternating list of keys and values."
555− :$$: 'Text "But got " :<>: 'ShowType (x:xs))
556
294
557-- | `PGTypeOf` forgets about @NULL@ and any column constraints.
295-- | `PGTypeOf` forgets about @NULL@ and any column constraints.
558type family PGTypeOf (ty :: NullityType) :: PGType where
296type family PGTypeOf (ty :: NullityType) :: PGType where
559 PGTypeOf (nullity pg) = pg
297 PGTypeOf (nullity pg) = pg
560
298
561−-- | `SameTypes` is a constraint that proves two `ColumnsType`s have the same
562−-- length and the same `ColumnType`s.
563−type family SameTypes (columns0 :: ColumnsType) (columns1 :: ColumnsType)
564− :: Constraint where
565− SameTypes '[] '[] = ()
566− SameTypes (column0 ::: def0 :=> ty0 ': columns0) (column1 ::: def1 :=> ty1 ': columns1)
567− = (ty0 ~ ty1, SameTypes columns0 columns1)
568−
569-- | Equality constraint on the underlying `PGType` of two columns.
299-- | Equality constraint on the underlying `PGType` of two columns.
570class SamePGType
300class SamePGType
571 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where
301 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where
@@ -575,44 +305,63 @@ instance ty0 ~ ty1 => SamePGType
575
305
576-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.
306-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.
577type family AllNotNull (columns :: ColumnsType) :: Constraint where
307type family AllNotNull (columns :: ColumnsType) :: Constraint where
308+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns
309+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns
310+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns
311+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns
312+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns
313+ AllNotNull (_ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns
578 AllNotNull '[] = ()
314 AllNotNull '[] = ()
579− AllNotNull (column ::: def :=> 'NotNull ty ': columns) = AllNotNull columns
580
315
581-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some
316-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some
582-- @NOT NULL@.
317-- @NOT NULL@.
583type family NotAllNull (columns :: ColumnsType) :: Constraint where
318type family NotAllNull (columns :: ColumnsType) :: Constraint where
584− NotAllNull (column ::: def :=> 'NotNull ty ': columns) = ()
319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
322+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
323+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
324+ NotAllNull (_ ::: _ :=> 'NotNull _ ': _) = ()
585− NotAllNull (column ::: def :=> 'Null ty ': columns) = NotAllNull columns
325+ NotAllNull (_ ::: _ :=> 'Null _ ': columns) = NotAllNull columns
586−
326+
587−-- | `NullifyType` is an idempotent that nullifies a `ColumnType`.
327+-- | `NullifyType` is an idempotent that nullifies a `NullityType`.
588type family NullifyType (ty :: NullityType) :: NullityType where
328type family NullifyType (ty :: NullityType) :: NullityType where
589 NullifyType ('Null ty) = 'Null ty
329 NullifyType ('Null ty) = 'Null ty
590 NullifyType ('NotNull ty) = 'Null ty
330 NullifyType ('NotNull ty) = 'Null ty
591
331
592−-- | `NullifyRelation` is an idempotent that nullifies a `ColumnsType`.
332+-- | `NullifyRow` is an idempotent that nullifies a `RowType`.
593−type family NullifyRelation (columns :: RelationType) :: RelationType where
333+type family NullifyRow (columns :: RowType) :: RowType where
594− NullifyRelation '[] = '[]
334+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': columns) =
335+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': column5 ::: NullifyType ty5 ': NullifyRow columns
336+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': columns) =
337+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': NullifyRow columns
338+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': columns) =
339+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': NullifyRow columns
340+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': columns) =
341+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': NullifyRow columns
342+ NullifyRow (column ::: ty ': column1 ::: ty1 ': columns) =
343+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': NullifyRow columns
595− NullifyRelation (column ::: ty ': columns) =
344+ NullifyRow (column ::: ty ': columns) =
596− column ::: NullifyType ty ': NullifyRelation columns
345+ column ::: NullifyType ty ': NullifyRow columns
597−
346+ NullifyRow '[] = '[]
347+
598−-- | `NullifyRelations` is an idempotent that nullifies a `RelationsType`
348+-- | `NullifyFrom` is an idempotent that nullifies a `FromType`
599-- used to nullify the left or right hand side of an outer join
349-- used to nullify the left or right hand side of an outer join
600-- in a `Squeal.PostgreSQL.Query.FromClause`.
350-- in a `Squeal.PostgreSQL.Query.FromClause`.
601−type family NullifyRelations (tables :: RelationsType) :: RelationsType where
351+type family NullifyFrom (tables :: FromType) :: FromType where
602− NullifyRelations '[] = '[]
352+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': table5 ::: columns5 ': tables) =
603− NullifyRelations (table ::: columns ': tables) =
353+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns5 ': table5 ::: NullifyRow columns4 ': NullifyFrom tables
604− table ::: NullifyRelation columns ': NullifyRelations tables
354+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': tables) =
605−
355+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns4 ': NullifyFrom tables
606−-- | 'RelationToRowType' drops the nullity constraints of its argument relations.
356+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': tables) =
607−type family RelationToRowType (tables :: RelationType) :: [(Symbol, PGType)] where
357+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': NullifyFrom tables
608− RelationToRowType (nullity x : xs) = x : RelationToRowType xs
358+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': tables) =
609− RelationToRowType '[] = '[]
359+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': NullifyFrom tables
610−
360+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': tables) =
611−-- | `Join` is simply promoted `++` and is used in @JOIN@s in
361+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': NullifyFrom tables
612−-- `Squeal.PostgreSQL.Query.FromClause`s.
362+ NullifyFrom (table ::: columns ': tables) =
613−type family Join xs ys where
363+ table ::: NullifyRow columns ': NullifyFrom tables
614− Join '[] ys = ys
364+ NullifyFrom '[] = '[]
615− Join (x ': xs) ys = x ': Join xs ys
616
365
617-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in
366-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in
618-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@
367-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@
@@ -622,62 +371,100 @@ type family Create alias x xs where
622 Create alias x (alias ::: y ': xs) = TypeError
371 Create alias x (alias ::: y ': xs) = TypeError
623 ('Text "Create: alias "
372 ('Text "Create: alias "
624 ':<>: 'ShowType alias
373 ':<>: 'ShowType alias
625− ':<>: 'Text "already in use")
374+ ':<>: 'Text "already exists")
626 Create alias y (x ': xs) = x ': Create alias y xs
375 Create alias y (x ': xs) = x ': Create alias y xs
627
376
377+type family CreateIfNotExists alias x xs where
378+ CreateIfNotExists alias x '[] = '[alias ::: x]
379+ CreateIfNotExists alias x (alias ::: y ': xs) = alias ::: y ': xs
380+ CreateIfNotExists alias y (x ': xs) = x ': CreateIfNotExists alias y xs
381+
382+type family CreateOrReplace alias x xs where
383+ CreateOrReplace alias x '[] = '[alias ::: x]
384+ CreateOrReplace alias x (alias ::: x ': xs) = alias ::: x ': xs
385+ CreateOrReplace alias x (alias ::: y ': xs) = TypeError
386+ ('Text "CreateOrReplace: expected type "
387+ ':<>: 'ShowType x
388+ ':<>: 'Text " but alias "
389+ ':<>: 'ShowType alias
390+ ':<>: 'Text " has type "
391+ ':<>: 'ShowType y)
392+ CreateOrReplace alias y (x ': xs) = x ': CreateOrReplace alias y xs
393+
628-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@
394-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@
629-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements
395-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements
630-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.
396-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.
631type family Drop alias xs where
397type family Drop alias xs where
398+ Drop alias '[] = TypeError
399+ ('Text "Drop: alias "
400+ ':<>: 'ShowType alias
401+ ':<>: 'Text " does not exist" )
632− Drop alias ((alias ::: x) ': xs) = xs
402+ Drop alias (alias ::: x ': xs) = xs
633 Drop alias (x ': xs) = x ': Drop alias xs
403 Drop alias (x ': xs) = x ': Drop alias xs
634
404
405+type family DropSchemum alias sch xs where
406+ DropSchemum alias sch '[] = TypeError
407+ ('Text "DropSchemum: alias "
408+ ':<>: 'ShowType alias
409+ ':<>: 'Text " does not exist" )
410+ DropSchemum alias sch (alias ::: sch x ': xs) = xs
411+ DropSchemum alias sch0 (alias ::: sch1 x ': xs) = TypeError
412+ ('Text "DropSchemum: expected schemum "
413+ ':<>: 'ShowType sch0
414+ ':<>: 'Text " but alias "
415+ ':<>: 'ShowType alias
416+ ':<>: 'Text " has schemum "
417+ ':<>: 'ShowType sch1)
418+ DropSchemum alias sch (x ': xs) = x ': DropSchemum alias sch xs
419+
420+type family DropIfExists alias xs where
421+ DropIfExists alias '[] = '[]
422+ DropIfExists alias (alias ::: x ': xs) = xs
423+ DropIfExists alias (x ': xs) = x ': DropIfExists alias xs
424+
425+type family DropSchemumIfExists alias sch xs where
426+ DropSchemumIfExists alias sch '[] = '[]
427+ DropSchemumIfExists alias sch (alias ::: sch x ': xs) = xs
428+ DropSchemumIfExists alias sch0 (alias ::: sch1 x ': xs) = TypeError
429+ ('Text "DropSchemumIfExists: expected schemum "
430+ ':<>: 'ShowType sch1
431+ ':<>: 'Text " but alias "
432+ ':<>: 'ShowType alias
433+ ':<>: 'Text " has schemum "
434+ ':<>: 'ShowType sch0)
435+ DropSchemumIfExists alias sch (x ': xs) = x ': DropSchemumIfExists alias sch xs
436+
635-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@
437-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@
636−-- with the type `x` and is used in `Squeal.PostgreSQL.Definition.alterTable`
438+-- with the type @x@ and is used in `Squeal.PostgreSQL.Definition.alterTable`
637-- and `Squeal.PostgreSQL.Definition.alterColumn`.
439-- and `Squeal.PostgreSQL.Definition.alterColumn`.
638type family Alter alias x xs where
440type family Alter alias x xs where
441+ Alter alias x '[] = TypeError
442+ ('Text "Alter: alias "
443+ ':<>: 'ShowType alias
444+ ':<>: 'Text " does not exist" )
639 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs
445 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs
640 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs
446 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs
641
447
642−-- type family AddConstraint constraint ty where
448+type family AlterIfExists alias x xs where
643−-- AddConstraint constraint (constraints :=> ty)
449+ AlterIfExists alias x '[] = '[]
644−-- = AsSet (constraint ': constraints) :=> ty
450+ AlterIfExists alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs
645−
451+ AlterIfExists alias x1 (x0 ': xs) = x0 ': AlterIfExists alias x1 xs
646−-- type family DeleteFromList (e :: elem) (list :: [elem]) where
647−-- DeleteFromList elem '[] = '[]
648−-- DeleteFromList elem (x ': xs) =
649−-- If (Cmp elem x == 'EQ) xs (x ': DeleteFromList elem xs)
650−
651−-- type family DropConstraint constraint ty where
652−-- DropConstraint constraint (constraints :=> ty)
653−-- = (AsSet (DeleteFromList constraint constraints)) :=> ty
654
452
655-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@
453-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@
656-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and
454-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and
657-- `Squeal.PostgreSQL.Definition.renameColumn`.
455-- `Squeal.PostgreSQL.Definition.renameColumn`.
658type family Rename alias0 alias1 xs where
456type family Rename alias0 alias1 xs where
457+ Rename alias0 alias1 '[] = TypeError
458+ ('Text "Rename: alias "
459+ ':<>: 'ShowType alias0
460+ ':<>: 'Text " does not exist" )
659 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs
461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs
660 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs
462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs
661
463
662−-- | `MapMaybes` is used in the binary instances of composite types.
464+type family RenameIfExists alias0 alias1 xs where
663−class MapMaybes xs where
465+ RenameIfExists alias x '[] = '[]
664− type family Maybes (xs :: [Type]) = (mxs :: [Type]) | mxs -> xs
466+ RenameIfExists alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs
665− maybes :: NP Maybe xs -> NP I (Maybes xs)
467+ RenameIfExists alias0 alias1 (x ': xs) = x ': RenameIfExists alias0 alias1 xs
666− unMaybes :: NP I (Maybes xs) -> NP Maybe xs
667−instance MapMaybes '[] where
668− type Maybes '[] = '[]
669− maybes Nil = Nil
670− unMaybes Nil = Nil
671−instance MapMaybes xs => MapMaybes (x ': xs) where
672− type Maybes (x ': xs) = Maybe x ': Maybes xs
673− maybes (x :* xs) = I x :* maybes xs
674− unMaybes (I mx :* xs) = mx :* unMaybes xs
675−
676−-- | `Nulls` is used to construct a `Squeal.Postgresql.Expression.row`
677−-- of a composite type.
678−type family Nulls tys where
679− Nulls '[] = '[]
680− Nulls (field ::: ty ': tys) = field ::: 'Null ty ': Nulls tys
681
468
682-- | Check if a `TableConstraint` involves a column
469-- | Check if a `TableConstraint` involves a column
683type family ConstraintInvolves column constraint where
470type family ConstraintInvolves column constraint where
@@ -699,201 +486,111 @@ type family DropIfConstraintsInvolve column constraints where
699-- `View` or `Typedef`.
486-- `View` or `Typedef`.
700data SchemumType
487data SchemumType
701 = Table TableType
488 = Table TableType
702− | View RelationType
489+ | View RowType
703 | Typedef PGType
490 | Typedef PGType
704−
491+ | Index IndexType
492+ | Function FunctionType
493+ | Operator OperatorType
494+ | UnsafeSchemum Symbol
495+
496+type FunctionType = ([NullityType], ReturnsType)
497+
498+data IndexType
499+ = Btree
500+ | Hash
501+ | Gist
502+ | Spgist
503+ | Gin
504+ | Brin
505+
506+data ReturnsType
507+ = Returns NullityType
508+ | ReturnsTable RowType
509+
510+data OperatorType
511+ = BinaryOp NullityType NullityType NullityType
512+ | LeftOp NullityType NullityType
513+ | RightOp NullityType NullityType
514+
705−-- | The schema of a database consists of a list of aliased,
515+{- | The schema of a database consists of a list of aliased,
706−-- user-defined `SchemumType`s.
516+user-defined `SchemumType`s.
517+
518+>>> :{
519+type family Schema :: SchemaType where
520+ Schema =
521+ '[ "users" ::: 'Table (
522+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
523+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
524+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
525+ ])
526+ , "emails" ::: 'Table (
527+ '[ "pk_emails" ::: 'PrimaryKey '["id"]
528+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
529+ ] :=>
530+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
531+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
532+ , "email" ::: 'NoDef :=> 'Null 'PGtext
533+ ])
534+ ]
535+:}
536+-}
707type SchemaType = [(Symbol,SchemumType)]
537type SchemaType = [(Symbol,SchemumType)]
708
538
709−-- | Used in `Squeal.Postgresql.Manipulation.with`.
539+{- |
710−type family With
540+A database contains one or more named schemas, which in turn contain tables.
711− (relations :: RelationsType)
541+The same object name can be used in different schemas without conflict;
712− (schema :: SchemaType)
542+for example, both schema1 and myschema can contain tables named mytable.
713− :: SchemaType where
543+Unlike databases, schemas are not rigidly separated:
714− With '[] schema = schema
544+a user can access objects in any of the schemas in the database they are connected to,
715− With (alias ::: rel ': rels) schema =
545+if they have privileges to do so.
716− alias ::: 'View rel ': With rels schema
546+
547+There are several reasons why one might want to use schemas:
548+
549+ * To allow many users to use one database without interfering with each other.
550+ * To organize database objects into logical groups to make them more manageable.
551+ * Third-party applications can be put into separate schemas
552+ so they do not collide with the names of other objects.
553+-}
554+type SchemasType = [(Symbol,SchemaType)]
555+
556+-- | A type family to use for a single schema database.
557+type family Public (schema :: SchemaType) :: SchemasType
558+ where Public schema = '["public" ::: schema]
717
559
718-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas
560-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas
719-- the overloaded label, `fromLabel` is used for column references,
561-- the overloaded label, `fromLabel` is used for column references,
720-- `label`s are used for enum terms. A `label` is called with
562-- `label`s are used for enum terms. A `label` is called with
721-- type application like `label @"beef"`.
563-- type application like `label @"beef"`.
722class IsPGlabel (label :: Symbol) expr where label :: expr
564class IsPGlabel (label :: Symbol) expr where label :: expr
723−instance label ~ label'
565+instance label ~ label1
566+ => IsPGlabel label (PGlabel label1) where label = PGlabel
567+instance labels ~ '[label]
724− => IsPGlabel label (PGlabel label') where label = PGlabel
568+ => IsPGlabel label (NP PGlabel labels) where label = PGlabel :* Nil
725-- | A `PGlabel` unit type with an `IsPGlabel` instance
569-- | A `PGlabel` unit type with an `IsPGlabel` instance
726data PGlabel (label :: Symbol) = PGlabel
570data PGlabel (label :: Symbol) = PGlabel
727−-- | Renders a label
728−renderLabel :: KnownSymbol label => proxy label -> ByteString
571+instance KnownSymbol label => RenderSQL (PGlabel label) where
729−renderLabel (_ :: proxy label) =
572+ renderSQL _ = "\'" <> renderSymbol @label <> "\'"
730− "\'" <> fromString (symbolVal (Proxy @label)) <> "\'"
731−-- | Renders a list of labels
732−renderLabels
733− :: All KnownSymbol labels => NP PGlabel labels -> [ByteString]
573+instance All KnownSymbol labels => RenderSQL (NP PGlabel labels) where
574+ renderSQL
575+ = commaSeparated
734−renderLabels = hcollapse
576+ . hcollapse
735− . hcmap (Proxy @KnownSymbol) (K . renderLabel)
577+ . hcmap (Proxy @KnownSymbol) (K . renderSQL)
736−
737−-- | The `PG` type family embeds a subset of Haskell types
738−-- as Postgres basic types.
739−--
740−-- >>> :kind! PG LocalTime
741−-- PG LocalTime :: PGType
742−-- = 'PGtimestamp
743−type family PG (hask :: Type) :: PGType where
744− PG Bool = 'PGbool
745− PG Int16 = 'PGint2
746− PG Int32 = 'PGint4
747− PG Int64 = 'PGint8
748− PG Word16 = 'PGint2
749− PG Word32 = 'PGint4
750− PG Word64 = 'PGint8
751− PG Scientific = 'PGnumeric
752− PG Float = 'PGfloat4
753− PG Double = 'PGfloat8
754− PG Char = 'PGchar 1
755− PG Text = 'PGtext
756− PG Lazy.Text = 'PGtext
757− PG ByteString = 'PGbytea
758− PG Lazy.ByteString = 'PGbytea
759− PG LocalTime = 'PGtimestamp
760− PG UTCTime = 'PGtimestamptz
761− PG Day = 'PGdate
762− PG TimeOfDay = 'PGtime
763− PG (TimeOfDay, TimeZone) = 'PGtimetz
764− PG DiffTime = 'PGinterval
765− PG UUID = 'PGuuid
766− PG (NetAddr IP) = 'PGinet
767− PG Value = 'PGjson
768− PG ty = TypeError
769− ('Text "There is no Postgres basic type for " ':<>: 'ShowType ty)
770−
771−-- | The `EnumFrom` type family embeds Haskell enum types, ADTs with
772−-- nullary constructors, as Postgres enum types
773−--
774−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
775−-- >>> instance Generic Schwarma
776−-- >>> instance HasDatatypeInfo Schwarma
777−-- >>> :kind! EnumFrom Schwarma
778−-- EnumFrom Schwarma :: PGType
779−-- = 'PGenum '["Beef", "Lamb", "Chicken"]
780−type family EnumFrom (hask :: Type) :: PGType where
781− EnumFrom hask = 'PGenum (LabelsFrom hask)
782−
783−-- | The `LabelsFrom` type family calculates the constructors of a
784−-- Haskell enum type.
785−--
786−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
787−-- >>> instance Generic Schwarma
788−-- >>> instance HasDatatypeInfo Schwarma
789−-- >>> :kind! LabelsFrom Schwarma
790−-- LabelsFrom Schwarma :: [Type.ConstructorName]
791−-- = '["Beef", "Lamb", "Chicken"]
792−type family LabelsFrom (hask :: Type) :: [Type.ConstructorName] where
793− LabelsFrom hask =
794− ConstructorNamesOf (ConstructorsOf (DatatypeInfoOf hask))
795−
796−-- | The `CompositeFrom` type family embeds Haskell record types as
797−-- Postgres composite types, as long as the record fields
798−-- are `Maybe`s of Haskell types that can be embedded as basic types
799−-- with the `PG` type family.
800−--
801−-- >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic
802−-- >>> instance Generic Row
803−-- >>> instance HasDatatypeInfo Row
804−-- >>> :kind! CompositeFrom Row
805−-- CompositeFrom Row :: PGType
806−-- = 'PGcomposite '['("a", 'PGint2), '("b", 'PGtimestamp)]
807−type family CompositeFrom (hask :: Type) :: PGType where
808− CompositeFrom hask =
809− 'PGcomposite (ZipAs (FieldNamesFrom hask) (FieldTypesFrom hask))
810−
811−-- | >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic
812−-- >>> instance Generic Row
813−-- >>> instance HasDatatypeInfo Row
814−-- >>> :kind! FieldNamesFrom Row
815−-- FieldNamesFrom Row :: [Type.FieldName]
816−-- = '["a", "b"]
817−type family FieldNamesFrom (hask :: Type) :: [Type.FieldName] where
818− FieldNamesFrom hask = FieldNamesOf (FieldsOf (DatatypeInfoOf hask))
819−
820−-- | >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic
821−-- >>> instance Generic Row
822−-- >>> instance HasDatatypeInfo Row
823−-- >>> :kind! FieldTypesFrom Row
824−-- FieldTypesFrom Row :: [PGType]
825−-- = '['PGint2, 'PGtimestamp]
826−type family FieldTypesFrom (hask :: Type) :: [PGType] where
827− FieldTypesFrom hask = FieldTypesOf (RecordCodeOf hask (Code hask))
828−
829−-- | Calculates constructors of a datatype.
830−type family ConstructorsOf (datatype :: Type.DatatypeInfo)
831− :: [Type.ConstructorInfo] where
832− ConstructorsOf ('Type.ADT _module _datatype constructors) =
833− constructors
834− ConstructorsOf ('Type.Newtype _module _datatype constructor) =
835− '[constructor]
836−
837−-- | Calculates the name of a nullary constructor, otherwise
838−-- generates a type error.
839−type family ConstructorNameOf (constructors :: Type.ConstructorInfo)
840− :: Type.ConstructorName where
841− ConstructorNameOf ('Type.Constructor name) = name
842− ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError
843− ('Text "ConstructorNameOf error: non-nullary constructor "
844− ':<>: 'Text name)
845− ConstructorNameOf ('Type.Record name _fields) = TypeError
846− ('Text "ConstructorNameOf error: non-nullary constructor "
847− ':<>: 'Text name)
848−
849−-- | Calculate the names of nullary constructors.
850−type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])
851− :: [Type.ConstructorName] where
852− ConstructorNamesOf '[] = '[]
853− ConstructorNamesOf (constructor ': constructors) =
854− ConstructorNameOf constructor ': ConstructorNamesOf constructors
855−
856−-- | Calculate the fields of a datatype.
857−type family FieldsOf (datatype :: Type.DatatypeInfo)
858− :: [Type.FieldInfo] where
859− FieldsOf ('Type.ADT _module _datatype '[ 'Type.Record _name fields]) =
860− fields
861− FieldsOf ('Type.Newtype _module _datatype ('Type.Record _name fields)) =
862− fields
863−
864−-- | Calculate the name of a field.
865−type family FieldNameOf (field :: Type.FieldInfo) :: Type.FieldName where
866− FieldNameOf ('Type.FieldInfo name) = name
867−
868−-- | Calculate the names of fields.
869−type family FieldNamesOf (fields :: [Type.FieldInfo])
870− :: [Type.FieldName] where
871− FieldNamesOf '[] = '[]
872− FieldNamesOf (field ': fields) = FieldNameOf field ': FieldNamesOf fields
873−
874−-- | >>> :kind! FieldTypeOf (Maybe Int16)
875−-- FieldTypeOf (Maybe Int16) :: PGType
876−-- = 'PGint2
877−type family FieldTypeOf (maybe :: Type) where
878− FieldTypeOf (Maybe hask) = PG hask
879− FieldTypeOf ty = TypeError
880− ('Text "FieldTypeOf error: non-Maybe type " ':<>: 'ShowType ty)
881−
882−-- | Calculate the types of fields.
883−type family FieldTypesOf (fields :: [Type]) where
884− FieldTypesOf '[] = '[]
885− FieldTypesOf (field ': fields) = FieldTypeOf field ': FieldTypesOf fields
886−
887−-- | Inspect the code of an algebraic datatype and ensure it's a product,
888−-- otherwise generate a type error
889−type family RecordCodeOf (hask :: Type) (code ::[[Type]]) :: [Type] where
890− RecordCodeOf _hask '[tys] = tys
891− RecordCodeOf hask _tys = TypeError
892− ('Text "RecordCodeOf error: non-Record type " ':<>: 'ShowType hask)
893
578
894-- | Is a type a valid JSON key?
579-- | Is a type a valid JSON key?
895−type PGjsonKey key = key `In` '[ 'PGint2, 'PGint4, 'PGtext ]
580+type PGJsonKey = '[ 'PGint2, 'PGint4, 'PGtext ]
896
581
897-- | Is a type a valid JSON type?
582-- | Is a type a valid JSON type?
898−type PGjson_ json = json `In` '[ 'PGjson, 'PGjsonb ]
583+type PGJsonType = '[ 'PGjson, 'PGjsonb ]
899−
584+
585+-- | Utility class for `AllUnique` to provide nicer error messages.
586+class IsNotElem x isElem where
587+instance IsNotElem x 'False where
588+instance (TypeError ( 'Text "Cannot assign to "
589+ ':<>: 'ShowType alias
590+ ':<>: 'Text " more than once"))
591+ => IsNotElem '(alias, a) 'True where
592+
593+-- | No elem of @xs@ appears more than once, in the context of assignment.
594+class AllUnique (xs :: [(Symbol, a)]) where
595+instance AllUnique '[] where
596+instance (IsNotElem x (Elem x xs), AllUnique xs) => AllUnique (x ': xs) where
squeal-postgresql/src/Squeal/PostgreSQL/Transaction.hs+101−74
@@ -1,7 +1,7 @@
1{-|
1{-|
2Module: Squeal.PostgreSQL.Transaction
2Module: Squeal.PostgreSQL.Transaction
3Description: Squeal transaction control language
3Description: Squeal transaction control language
4−Copyright: (c) Eitan Chatav, 2017
4+Copyright: (c) Eitan Chatav, 2019
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
@@ -9,98 +9,125 @@ Squeal transaction control language.
9-}
9-}
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12+ DataKinds
12− FlexibleContexts
13+ , FlexibleContexts
13 , LambdaCase
14 , LambdaCase
14 , OverloadedStrings
15 , OverloadedStrings
16+ , TypeInType
15#-}
17#-}
16
18
17module Squeal.PostgreSQL.Transaction
19module Squeal.PostgreSQL.Transaction
18 ( -- * Transaction
20 ( -- * Transaction
19 transactionally
21 transactionally
20 , transactionally_
22 , transactionally_
23+ , transactionallyRetry
24+ , ephemerally
25+ , ephemerally_
21 , begin
26 , begin
22 , commit
27 , commit
23 , rollback
28 , rollback
24− , transactionallySchema
25− , transactionallySchema_
26 -- * Transaction Mode
29 -- * Transaction Mode
27 , TransactionMode (..)
30 , TransactionMode (..)
28 , defaultMode
31 , defaultMode
29 , longRunningMode
32 , longRunningMode
30 , IsolationLevel (..)
33 , IsolationLevel (..)
31− , renderIsolationLevel
32 , AccessMode (..)
34 , AccessMode (..)
33− , renderAccessMode
34 , DeferrableMode (..)
35 , DeferrableMode (..)
35− , renderDeferrableMode
36 ) where
36 ) where
37
37
38−import Control.Exception.Lifted
38+import UnliftIO
39−import Control.Monad.Base
40−import Control.Monad.Trans.Control
41−import Data.ByteString
42−import Data.Monoid
43−import Generics.SOP
44−
45−import qualified Database.PostgreSQL.LibPQ as LibPQ
46
39
47import Squeal.PostgreSQL.Manipulation
40import Squeal.PostgreSQL.Manipulation
48import Squeal.PostgreSQL.Render
41import Squeal.PostgreSQL.Render
49import Squeal.PostgreSQL.PQ
42import Squeal.PostgreSQL.PQ
50−import Squeal.PostgreSQL.Schema
51
43
52−-- | Run a schema invariant computation `transactionally`.
44+{- | Run a computation `transactionally`;
45+first `begin`,
46+then run the computation,
47+`onException` `rollback` and rethrow the exception,
48+otherwise `commit` and `return` the result.
49+-}
53transactionally
50transactionally
54− :: (MonadBaseControl IO tx, MonadPQ schema tx)
51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)
55 => TransactionMode
52 => TransactionMode
56 -> tx x -- ^ run inside a transaction
53 -> tx x -- ^ run inside a transaction
57 -> tx x
54 -> tx x
58transactionally mode tx = mask $ \restore -> do
55transactionally mode tx = mask $ \restore -> do
59− _ <- begin mode
56+ manipulate_ $ begin mode
60− result <- restore tx `onException` rollback
57+ result <- restore tx `onException` (manipulate_ rollback)
61− _ <- commit
58+ manipulate_ commit
62 return result
59 return result
63
60
64−-- | Run a schema invariant computation `transactionally_` in `defaultMode`.
61+-- | Run a computation `transactionally_`, in `defaultMode`.
65transactionally_
62transactionally_
66− :: (MonadBaseControl IO tx, MonadPQ schema tx)
63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)
67 => tx x -- ^ run inside a transaction
64 => tx x -- ^ run inside a transaction
68 -> tx x
65 -> tx x
69transactionally_ = transactionally defaultMode
66transactionally_ = transactionally defaultMode
70
67
71−-- | @BEGIN@ a transaction.
68+{- |
69+`transactionallyRetry` a computation;
70+
71+* first `begin`,
72+* then `try` the computation,
73+ - if it raises a serialization failure then `rollback` and restart the transaction,
74+ - if it raises any other exception then `rollback` and rethrow the exception,
75+ - otherwise `commit` and `return` the result.
76+-}
77+transactionallyRetry
78+ :: (MonadUnliftIO tx, MonadPQ schemas tx)
72−begin :: MonadPQ schema tx => TransactionMode -> tx (K Result NilRelation)
79+ => TransactionMode
73−begin mode = manipulate . UnsafeManipulation $
80+ -> tx x -- ^ run inside a transaction
74− "BEGIN" <+> renderTransactionMode mode <> ";"
81+ -> tx x
82+transactionallyRetry mode tx = mask $ \restore ->
83+ loop . try $ do
84+ x <- restore tx
85+ manipulate_ commit
86+ return x
87+ where
88+ loop attempt = do
89+ manipulate_ $ begin mode
90+ attempt >>= \case
91+ Left (PQException (PQState _ (Just "40001") _)) -> do
92+ manipulate_ rollback
93+ loop attempt
94+ Left err -> do
95+ manipulate_ rollback
96+ throwIO err
97+ Right x -> return x
98+
99+{- | Run a computation `ephemerally`;
100+Like `transactionally` but always `rollback`, useful in testing.
101+-}
102+ephemerally
103+ :: (MonadUnliftIO tx, MonadPQ schemas tx)
104+ => TransactionMode
105+ -> tx x -- ^ run inside an ephemeral transaction
106+ -> tx x
107+ephemerally mode tx = mask $ \restore -> do
108+ manipulate_ $ begin mode
109+ result <- restore tx `onException` (manipulate_ rollback)
110+ manipulate_ rollback
111+ return result
75
112
76−-- | @COMMIT@ a schema invariant transaction.
113+{- | Run a computation `ephemerally` in `defaultMode`. -}
77−commit :: MonadPQ schema tx => tx (K Result NilRelation)
114+ephemerally_
78−commit = manipulate $ UnsafeManipulation "COMMIT;"
115+ :: (MonadUnliftIO tx, MonadPQ schemas tx)
116+ => tx x -- ^ run inside an ephemeral transaction
117+ -> tx x
118+ephemerally_ = ephemerally defaultMode
119+
120+-- | @BEGIN@ a transaction.
121+begin :: TransactionMode -> Manipulation_ schemas () ()
122+begin mode = UnsafeManipulation $ "BEGIN" <+> renderSQL mode
79
123
80−-- | @ROLLBACK@ a schema invariant transaction.
124+-- | @COMMIT@ a transaction.
81−rollback :: MonadPQ schema tx => tx (K Result NilRelation)
125+commit :: Manipulation_ schemas () ()
82−rollback = manipulate $ UnsafeManipulation "ROLLBACK;"
126+commit = UnsafeManipulation "COMMIT"
83
127
84−-- | Run a schema changing computation `transactionallySchema`.
128+-- | @ROLLBACK@ a transaction.
85−transactionallySchema
129+rollback :: Manipulation_ schemas () ()
86− :: MonadBaseControl IO io
130+rollback = UnsafeManipulation "ROLLBACK"
87− => TransactionMode
88− -> PQ schema0 schema1 io x
89− -> PQ schema0 schema1 io x
90−transactionallySchema mode u = PQ $ \ conn -> mask $ \ restore -> do
91− _ <- liftBase . LibPQ.exec (unK conn) $
92− "BEGIN" <+> renderTransactionMode mode <> ";"
93− x <- restore (unPQ u conn)
94− `onException` (liftBase (LibPQ.exec (unK conn) "ROLLBACK"))
95− _ <- liftBase $ LibPQ.exec (unK conn) "COMMIT"
96− return x
97−
98−-- | Run a schema changing computation `transactionallySchema_` in `DefaultMode`.
99−transactionallySchema_
100− :: MonadBaseControl IO io
101− => PQ schema0 schema1 io x
102− -> PQ schema0 schema1 io x
103−transactionallySchema_ = transactionallySchema defaultMode
104
131
105-- | The available transaction characteristics are the transaction `IsolationLevel`,
132-- | The available transaction characteristics are the transaction `IsolationLevel`,
106-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.
133-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.
@@ -113,7 +140,7 @@ data TransactionMode = TransactionMode
113-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
140-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
114-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.
141-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.
115defaultMode :: TransactionMode
142defaultMode :: TransactionMode
116−defaultMode = TransactionMode Serializable ReadWrite NotDeferrable
143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable
117
144
118-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
145-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
119-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.
146-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.
@@ -122,12 +149,12 @@ longRunningMode :: TransactionMode
122longRunningMode = TransactionMode Serializable ReadOnly Deferrable
149longRunningMode = TransactionMode Serializable ReadOnly Deferrable
123
150
124-- | Render a `TransactionMode`.
151-- | Render a `TransactionMode`.
125−renderTransactionMode :: TransactionMode -> ByteString
152+instance RenderSQL TransactionMode where
126−renderTransactionMode mode =
153+ renderSQL mode =
127− "ISOLATION LEVEL"
154+ "ISOLATION LEVEL"
128− <+> renderIsolationLevel (isolationLevel mode)
155+ <+> renderSQL (isolationLevel mode)
129− <+> renderAccessMode (accessMode mode)
156+ <+> renderSQL (accessMode mode)
130− <+> renderDeferrableMode (deferrableMode mode)
157+ <+> renderSQL (deferrableMode mode)
131
158
132-- | The SQL standard defines four levels of transaction isolation.
159-- | The SQL standard defines four levels of transaction isolation.
133-- The most strict is `Serializable`, which is defined by the standard in a paragraph
160-- The most strict is `Serializable`, which is defined by the standard in a paragraph
@@ -178,12 +205,12 @@ data IsolationLevel
178 deriving (Show, Eq)
205 deriving (Show, Eq)
179
206
180-- | Render an `IsolationLevel`.
207-- | Render an `IsolationLevel`.
181−renderIsolationLevel :: IsolationLevel -> ByteString
208+instance RenderSQL IsolationLevel where
182−renderIsolationLevel = \case
209+ renderSQL = \case
183− Serializable -> "SERIALIZABLE"
210+ Serializable -> "SERIALIZABLE"
184− ReadCommitted -> "READ COMMITTED"
211+ ReadCommitted -> "READ COMMITTED"
185− ReadUncommitted -> "READ UNCOMMITTED"
212+ ReadUncommitted -> "READ UNCOMMITTED"
186− RepeatableRead -> "REPEATABLE READ"
213+ RepeatableRead -> "REPEATABLE READ"
187
214
188-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.
215-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.
189-- `ReadWrite` is the default. When a transaction is `ReadOnly`,
216-- `ReadWrite` is the default. When a transaction is `ReadOnly`,
@@ -200,10 +227,10 @@ data AccessMode
200 deriving (Show, Eq)
227 deriving (Show, Eq)
201
228
202-- | Render an `AccessMode`.
229-- | Render an `AccessMode`.
203−renderAccessMode :: AccessMode -> ByteString
230+instance RenderSQL AccessMode where
204−renderAccessMode = \case
231+ renderSQL = \case
205− ReadWrite -> "READ WRITE"
232+ ReadWrite -> "READ WRITE"
206− ReadOnly -> "READ ONLY"
233+ ReadOnly -> "READ ONLY"
207
234
208-- | The `Deferrable` transaction property has no effect
235-- | The `Deferrable` transaction property has no effect
209-- unless the transaction is also `Serializable` and `ReadOnly`.
236-- unless the transaction is also `Serializable` and `ReadOnly`.
@@ -219,7 +246,7 @@ data DeferrableMode
219 deriving (Show, Eq)
246 deriving (Show, Eq)
220
247
221-- | Render a `DeferrableMode`.
248-- | Render a `DeferrableMode`.
222−renderDeferrableMode :: DeferrableMode -> ByteString
249+instance RenderSQL DeferrableMode where
223−renderDeferrableMode = \case
250+ renderSQL = \case
224− Deferrable -> "DEFERRABLE"
251+ Deferrable -> "DEFERRABLE"
225− NotDeferrable -> "NOT DEFERRABLE"
252+ NotDeferrable -> "NOT DEFERRABLE"
squeal-postgresql/test/Doc.hsnew file+6
@@ -0,0 +1,6 @@
1+module Main (main) where
2+
3+import Test.DocTest
4+
5+main :: IO ()
6+main = doctest [ "-isrc", "src" ]
squeal-postgresql/test/DocTest.hsdeleted−18
@@ -1,18 +0,0 @@
1−module Main (main) where
2−
3−import Test.DocTest
4−
5−main :: IO ()
6−main = doctest
7− [ "-isrc"
8− , "src/Squeal/PostgreSQL.hs"
9− , "src/Squeal/PostgreSQL/Binary.hs"
10− , "src/Squeal/PostgreSQL/Definition.hs"
11− , "src/Squeal/PostgreSQL/Manipulation.hs"
12− , "src/Squeal/PostgreSQL/Query.hs"
13− , "src/Squeal/PostgreSQL/Expression.hs"
14− , "src/Squeal/PostgreSQL/PQ.hs"
15− , "src/Squeal/PostgreSQL/Migration.hs"
16− , "src/Squeal/PostgreSQL/Transaction.hs"
17− , "src/Squeal/PostgreSQL/Pool.hs"
18− ]
squeal-postgresql/test/Property.hsnew file+166
@@ -0,0 +1,166 @@
1+{-# LANGUAGE
2+ DataKinds
3+ , GADTs
4+ , LambdaCase
5+ , OverloadedLabels
6+ , OverloadedStrings
7+ , TypeApplications
8+ , TypeOperators
9+#-}
10+
11+module Main (main) where
12+
13+import Control.Monad.Trans
14+import Data.ByteString (ByteString)
15+import Data.ByteString.Char8 (unpack)
16+import Data.Scientific (fromFloatDigits)
17+import Data.Fixed (Fixed(MkFixed), Micro, Pico)
18+import Data.String (IsString(fromString))
19+import Data.Time
20+import Squeal.PostgreSQL hiding (check, defaultMain, Group)
21+import Hedgehog hiding (Range)
22+import qualified Hedgehog.Gen as Gen
23+import qualified Hedgehog.Main as Main
24+import qualified Hedgehog.Range as Range
25+
26+main :: IO ()
27+main = Main.defaultMain [checkSequential roundtrips]
28+
29+roundtrips :: Group
30+roundtrips = Group "roundtrips"
31+ [ roundtrip int2 genInt16
32+ , roundtrip int4 genInt32
33+ , roundtrip int8 genInt64
34+ , roundtrip bool Gen.bool
35+ , roundtrip numeric genScientific
36+ , roundtrip float4 genFloat
37+ , roundtrip float8 genDouble
38+ , roundtripOn normalizeTimeOfDay time genTimeOfDay
39+ -- , roundtrip timetz genTimeWithZone normalizeTimeWithZone
40+ , roundtripOn normalizeLocalTime timestamp genLocalTime
41+ , roundtrip timestamptz genUTCTime
42+ , roundtrip date genDay
43+ , roundtrip interval genDiffTime
44+ , roundtripOn normalizeIntRange int4range (genRange genInt32)
45+ , roundtripOn normalizeIntRange int8range (genRange genInt64)
46+ , roundtrip numrange (genRange genScientific)
47+ , roundtripOn (fmap normalizeLocalTime) tsrange (genRange genLocalTime)
48+ , roundtrip tstzrange (genRange genUTCTime)
49+ , roundtripOn normalizeIntRange daterange (genRange genDay)
50+ ]
51+ where
52+ genInt16 = Gen.int16 Range.exponentialBounded
53+ genInt32 = Gen.int32 Range.exponentialBounded
54+ genInt64 = Gen.int64 Range.exponentialBounded
55+ genScientific = fromFloatDigits <$> genFloat
56+ genPosFloat = Gen.float
57+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)
58+ genFloat = Gen.prune $ Gen.choice
59+ [ genPosFloat
60+ , negate <$> genPosFloat
61+ , Gen.element [0,1/0] ]
62+ genPosDouble = Gen.double
63+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)
64+ genDouble = Gen.prune $ Gen.choice
65+ [ genPosDouble
66+ , negate <$> genPosDouble
67+ , Gen.element [0,1/0] ]
68+ genRange gen = do
69+ lb <- gen
70+ ub <- Gen.filter (lb <) gen
71+ Gen.element
72+ [ Empty, singleton lb, whole
73+ , lb <=..<= ub , lb <=..< ub, lb <..<= ub, lb <..< ub
74+ , atLeast lb, moreThan lb, atMost ub, lessThan ub ]
75+ genDay = do
76+ y <- toInteger <$> Gen.int (Range.constant 2000 2019)
77+ m <- Gen.int (Range.constant 1 12)
78+ d <- Gen.int (Range.constant 1 28)
79+ return $ fromGregorian y m d
80+ genDiffTime = secondsToDiffTime . toInteger <$>
81+ Gen.int (Range.constant 0 86401)
82+ genUTCTime = UTCTime <$> genDay <*> genDiffTime
83+ genTimeOfDay = do
84+ h <- Gen.int (Range.constant 0 23)
85+ m <- Gen.int (Range.constant 0 59)
86+ s <- MkFixed . toInteger <$> Gen.int (Range.constant 0 59)
87+ return $ TimeOfDay h m s
88+ genLocalTime = LocalTime <$> genDay <*> genTimeOfDay
89+ -- genTimeZone = Gen.element $ map (read @TimeZone)
90+ -- [ "UTC", "UT", "GMT", "EST", "EDT", "CST"
91+ -- , "CDT", "MST", "MDT", "PST", "PDT" ]
92+ -- genTimeWithZone = (,) <$> genTimeOfDay <*> genTimeZone
93+
94+roundtrip
95+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)
96+ => TypeExpression schemas ('NotNull ty)
97+ -> Gen x
98+ -> (PropertyName, Property)
99+roundtrip = roundtripOn id
100+
101+roundtripOn
102+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)
103+ => (x -> x)
104+ -> TypeExpression schemas ('NotNull ty)
105+ -> Gen x
106+ -> (PropertyName, Property)
107+roundtripOn norm ty gen = propertyWithName $ do
108+ x <- forAll gen
109+ Just (Only y) <- lift . withConnection connectionString $
110+ firstRow =<< runQueryParams
111+ (values_ (parameter @1 ty `as` #fromOnly)) (Only x)
112+ norm x === y
113+ where
114+ propertyWithName prop =
115+ (fromString (unpack (renderSQL ty)), property prop)
116+
117+maxPosFloat :: RealFloat a => a
118+maxPosFloat = x
119+ where
120+ n = floatDigits x
121+ b = floatRadix x
122+ (_, u) = floatRange x
123+ x = encodeFloat (b^n - 1) (u - n)
124+
125+minPosFloat :: RealFloat a => a
126+minPosFloat = x
127+ where
128+ n = floatDigits x
129+ b = floatRadix x
130+ (l, _) = floatRange x
131+ x = encodeFloat (b^n - 1) (l - n - 1)
132+
133+connectionString :: ByteString
134+connectionString = "host=localhost port=5432 dbname=exampledb"
135+
136+normalizeIntRange :: (Enum int, Ord int) => Range int -> Range int
137+normalizeIntRange = \case
138+ Empty -> Empty
139+ NonEmpty l u ->
140+ let
141+ l' = normalizeL l
142+ u' = normalizeU u
143+ in if emptyNormalized l' u' then Empty else NonEmpty l' u'
144+ where
145+ normalizeL = \case
146+ Open l -> Closed (succ l)
147+ normalized -> normalized
148+ normalizeU = \case
149+ Closed u -> Open (succ u)
150+ normalized -> normalized
151+ emptyNormalized (Closed l) (Open u) = l >= u
152+ emptyNormalized _ _ = False
153+
154+normalizeTimeOfDay :: TimeOfDay -> TimeOfDay
155+normalizeTimeOfDay (TimeOfDay h m s) = TimeOfDay h m
156+ . fromRational @Pico
157+ . toRational @Micro
158+ . fromRational @Micro
159+ . toRational @Pico
160+ $ s
161+
162+normalizeLocalTime :: LocalTime -> LocalTime
163+normalizeLocalTime (LocalTime d t) = LocalTime d (normalizeTimeOfDay t)
164+
165+-- normalizeTimeWithZone :: (TimeOfDay, TimeZone) -> (TimeOfDay, TimeZone)
166+-- normalizeTimeWithZone (t, z) = (normalizeTimeOfDay t, z)
squeal-postgresql/test/Spec.hsnew file+136
@@ -0,0 +1,136 @@
1+{-# LANGUAGE
2+ DataKinds
3+ , DeriveAnyClass
4+ , DeriveGeneric
5+ , DerivingStrategies
6+ , DuplicateRecordFields
7+ , FlexibleContexts
8+ , OverloadedLabels
9+ , OverloadedLists
10+ , OverloadedStrings
11+ , TypeApplications
12+ , TypeFamilies
13+ , TypeInType
14+ , TypeOperators
15+#-}
16+
17+module Main (main) where
18+
19+import Control.Concurrent.Async (replicateConcurrently)
20+import Data.ByteString (ByteString)
21+import Data.Int (Int32)
22+import Data.Text (Text)
23+import Test.Hspec
24+
25+import qualified Generics.SOP as SOP
26+import qualified GHC.Generics as GHC
27+
28+import Squeal.PostgreSQL
29+
30+main :: IO ()
31+main = hspec spec
32+
33+type Schemas = Public
34+ '[ "users" ::: 'Table (
35+ '[ "pk_users" ::: 'PrimaryKey '["id"]
36+ , "unique_names" ::: 'Unique '["name"]
37+ ] :=>
38+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
39+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext ] ) ]
40+
41+data User = User
42+ { userName :: Text
43+ } deriving stock (Eq, Show, GHC.Generic)
44+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
45+
46+insertUser :: Manipulation_ Schemas User ()
47+insertUser = insertInto_ #users
48+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))
49+
50+setup :: Definition (Public '[]) Schemas
51+setup =
52+ createTable #users
53+ ( serial `as` #id :*
54+ notNullable text `as` #name )
55+ ( primaryKey #id `as` #pk_users :*
56+ unique #name `as` #unique_names )
57+
58+teardown :: Definition Schemas (Public '[])
59+teardown = dropTable #users
60+
61+silence :: MonadPQ schemas pq => pq ()
62+silence = manipulate_ $
63+ UnsafeManipulation "SET client_min_messages TO WARNING;"
64+
65+setupDB :: IO ()
66+setupDB = withConnection connectionString $
67+ silence & pqThen (define setup)
68+
69+dropDB :: IO ()
70+dropDB = withConnection connectionString $
71+ silence & pqThen (define teardown)
72+
73+connectionString :: ByteString
74+connectionString = "host=localhost port=5432 dbname=exampledb"
75+
76+spec :: Spec
77+spec = before_ setupDB . after_ dropDB $ do
78+
79+ describe "Exceptions" $ do
80+
81+ let
82+ testUser = User "TestUser"
83+ newUser = manipulateParams_ insertUser
84+ insertUserTwice = newUser testUser >> newUser testUser
85+ err23505 = PQException $ PQState FatalError (Just "23505")
86+ (Just "ERROR: duplicate key value violates unique constraint \"unique_names\"\nDETAIL: Key (name)=(TestUser) already exists.\n")
87+
88+ it "should be thrown for constraint violation" $
89+ withConnection connectionString insertUserTwice
90+ `shouldThrow` (== err23505)
91+
92+ it "should be rethrown for constraint violation in a transaction" $
93+ withConnection connectionString (transactionally_ insertUserTwice)
94+ `shouldThrow` (== err23505)
95+
96+ describe "Pools" $
97+
98+ it "should manage concurrent transactions" $ do
99+ pool <- createConnectionPool
100+ "host=localhost port=5432 dbname=exampledb" 1 0.5 10
101+ let
102+ query :: Query_ (Public '[]) () (Only Char)
103+ query = values_ (literal 'a' `as` #fromOnly)
104+ session = usingConnectionPool pool . transactionally_ $ do
105+ result <- runQuery query
106+ Just (Only chr) <- firstRow result
107+ return chr
108+ chrs <- replicateConcurrently 10 session
109+ chrs `shouldSatisfy` all (== 'a')
110+
111+ describe "Ranges" $
112+
113+ it "should correctly decode ranges" $ do
114+
115+ rangesOut <- withConnection connectionString $ do
116+ let
117+ query :: Query_ (Public '[]) () (Only (Range Int32))
118+ query = values
119+ ( range int4range (atLeast 3) `as` #fromOnly )
120+ [ range int4range (3 <=..< 5) `as` #fromOnly
121+ , range int4range Empty `as` #fromOnly
122+ , range int4range whole `as` #fromOnly ]
123+ getRows =<< runQuery query
124+ (fromOnly <$> rangesOut :: [Range Int32]) `shouldBe`
125+ [ atLeast 3, 3 <=..< 5, Empty, whole ]
126+
127+ describe "Parameters" $ do
128+
129+ it "should run queries that don't reference all their parameters" $ do
130+
131+ out <- withConnection connectionString $ do
132+ let
133+ query :: Query_ (Public '[]) (Char,Int32) (Only Int32)
134+ query = values_ (param @2 `as` #fromOnly)
135+ firstRow =<< runQueryParams query ('a', 3 :: Int32)
136+ (fromOnly <$> out :: Maybe Int32) `shouldBe` Just 3
squeal-presentation-raveline.mdnew file+794
@@ -0,0 +1,794 @@
1+# Squeal
2+
3+_A bridge between SQL and Haskell_
4+
5+by [@Raveline](https://github.com/raveline)
6+
7+---
8+
9+# Rationale
10+
11+Using `postgresql-simple` you have a typical "Trial, error, despair" workflow:
12+
13+- Write query manually or semi-automatically
14+
15+- Write haskell code using the query
16+
17+- Pray that the query syntax is correct
18+
19+- Pray that it returns what you want
20+
21+- Realize the inefficiency of prayer when it comes to SQL
22+
23+- Iterate till it works
24+
25+---
26+
27+![Can't take this anymore](http://gif.eraveline.eu/static/img/0x16e.gif)
28+
29+---
30+
31+# Use your best friend: GHC
32+
33+Squeal provides several eDSL to make your SQL typesafe:
34+
35+- Type level eDSL to express schema;
36+
37+- Value level eDSL to manipulate schema (plus migration, yeehaw !);
38+
39+- Type level eDSL to express queries;
40+
41+- Value level eDSL to perform queries
42+
43+However, it's not an ORM. There's no caching, lazy loading - you retain control over your memory. Also, joins - and mostly aggregation after joins - have to be handled manually.
44+
45+---
46+
47+# Part I. Schema & migration
48+
49+---
50+
51+# The Schema
52+
53+- The schema will be used to validate _everything_: migration, queries, etc.
54+
55+- A schema is mostly a collection of tables.
56+
57+- In this presentation, we will create a very basic database modeling a parliament. We will store _members of parliament_ and _parliamentary groups_.
58+
59+- A simple Schema to represent a Parliament could be:
60+
61+```haskell
62+type Schema = '[ "mp" ::: 'Table MemberOfParliament
63+ , "groupp" ::: 'Table ParliamentGroup ]
64+```
65+
66+---
67+
68+> _note_ We need the `DataKinds` extension to be able to express heterogenous lists containing
69+> specific types like this one.
70+
71+> You can perfectly call your table "group" and not "groupp" even though it is a
72+> keyword in SQL - Squeal queries will be properly escaped.
73+
74+---
75+
76+# A small example
77+
78+```haskell
79+type ParliamentaryGroup =
80+ '[ "pk_groupp" ::: 'PrimaryKey '["groupp_id"]]
81+ :=>
82+ '[ "groupp_id" ::: 'NoDef :=> 'NotNull 'PGuuid
83+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
84+ ]
85+```
86+
87+- That's a whole simple table defined in one go.
88+
89+- `:::` lets us define a column or a constraint.
90+
91+- `:=>` associates the constraints to the column.
92+
93+- Let's split constraints and column to study the syntax a bit more.
94+
95+---
96+
97+> _note_ We are using `:::` and `:=>` to quickly express associations when writing
98+> our schema. We need the `TypeOperators` extension.]
99+
100+---
101+
102+![What does this means ?!](http://gif.eraveline.eu/static/img/0x27e.gif)
103+
104+---
105+
106+# Defining a table
107+
108+```haskell
109+type MemberOfParliament =
110+ '[ "pk_mp" ::: 'PrimaryKey '["mp_id"]
111+ , "fk_mp_groupp" ::: 'ForeignKey '["mp_group"] "groupp" '["groupp_id"]
112+ ] :=> MpCols
113+```
114+
115+- A table is a collection of constraints associated to a collection of columns.
116+
117+- We defined a table named "mp".
118+
119+- It has a constraint named "pk_mp", defining its primary key on column "mp_id".
120+
121+- It has a constraint named "fk_mp_groupp" defining a foreign key on column "mg_group", connected to the column "groupp_id" of table "groupp".
122+
123+- These constraints will be associated to the columns defined in `MpCols`.
124+
125+---
126+
127+# Defining columns
128+
129+```haskell
130+type MpCols =
131+ '[ "mp_id" ::: 'NoDef :=> 'NotNull 'PGuuid
132+ , "first_name" ::: 'NoDef :=> 'NotNull 'PGtext
133+ , "last_name" ::: 'NoDef :=> 'NotNull 'PGtext
134+ ]
135+```
136+
137+- A listing of column associate, for each element:
138+
139+ * a name;
140+
141+ * the mention of an eventual default value;
142+
143+ * the nullability;
144+
145+ * the type (obviously).
146+
147+---
148+
149+> _note_ GHC is already helping. If I named the "mp_id" column differently,
150+> GHC would yell because I promised a primary key constraint on a column named `mp_id`, so there must be one.]
151+
152+---
153+
154+# Implementating the schema
155+
156+- We will carry this schema type pretty much everywhere.
157+
158+- But before we play with this schema, we need to implement it.
159+
160+---
161+
162+```haskell
163+setup :: Definition '[] Schema
164+setup =
165+ createTable #groupp
166+ ( notNullable uuid `as` #groupp_id
167+ :* notNullable text `as` #name)
168+ ( primaryKey #groupp_id `as` #pk_groupp )
169+ >>> createTable #mp
170+ ( notNullable uuid `as` #mp_id
171+ :* notNullable text `as` #first_name
172+ :* notNullable text `as` #last_name
173+ :* notNullable text `as` #mp_group)
174+ ( primaryKey #mp_id `as` #pk_mp
175+ :* foreignKey #mp_group #groupp #groupp_id
176+ OnDeleteCascade OnUpdateCascade
177+ `as` #fk_mp_groupp)
178+```
179+
180+---
181+
182+# Damn, that's verbose
183+
184+- Yes. But you need verbosity to get type safety.
185+
186+- On the plus side, it's fairly straightforward.
187+
188+- You use `:*` to compose the element of the heterogenous list of columns.
189+
190+- You use `>>>` to compose table creation.
191+
192+> _note_ The compiler will catch any mistype between Schema and
193+> definition; wrong nullability, wrong type, wrong name, etc.
194+
195+---
196+
197+> _note_ You'll also need `OverloadedLabels`, for naming stuff.
198+> This is mostly to avoid having to write manual proxies all
199+> the time and for convenience.
200+
201+---
202+
203+# Setting up the schema
204+
205+- Squeal comes with a very good migration manager, handling _upgrades_ AND
206+_downgrades_.
207+
208+- A migration is a simple type:
209+
210+```haskell
211+Migration io schema0 schema1
212+```
213+
214+- The first parameter is a BaseMonad (typically, IO).
215+
216+- The second parameter is "the current schema of your DB".
217+
218+- The last one is "what you will migrate to".
219+
220+- The `Definition` type used to define upgrade and downgrade functions use the
221+ same logic (from one schema to the other).
222+
223+---
224+
225+# Defining our first migration
226+
227+- We have the setup bit, we need the teardown:
228+
229+```haskell
230+tearDown :: Definition Schema '[]
231+tearDown = dropTable #mp >>> dropTable #groupp
232+```
233+
234+> _note_ GHC will also detect the _proper_ order of what you typed in
235+> downgrade and upgrade should there be any conflict (with foreign keys).
236+
237+```haskell
238+initDB :: Migration IO '[] Schema
239+initDB =
240+ Migration { name = "Schema creation"
241+ , up = void $ define setup
242+ , down = void $ define tearDown }
243+```
244+
245+---
246+
247+# Simple migrator example
248+
249+```haskell
250+main :: IO ()
251+main = do
252+ printSQL setup
253+ void $ withConnection connectionString $
254+ migrateUp $ single initDB
255+```
256+
257+- We print the migration query; you can do this for all queries generated through Squeal.
258+
259+- We use `migrateUp` to perform the migration.
260+
261+- You can run several migration at the same time, to run only one use `single`.
262+
263+---
264+
265+![That was easy](http://gif.eraveline.eu/static/img/0x47f.gif)
266+
267+---
268+
269+# Part II. Insertions
270+
271+---
272+
273+# Manipulations & Queries
274+
275+Besides the specific case of migration, you will mostly perform:
276+
277+- `Manipulation` : inserting, updating and deleting data.
278+
279+- `Query` : fetching data.
280+
281+- Both types are parametric over the same things:
282+
283+ * A schema
284+
285+ * Input parameters
286+
287+ * Output
288+
289+- Simplified, they look like this:
290+
291+```haskell
292+Manipulation schema params columns
293+
294+Query schema params columns
295+```
296+
297+
298+---
299+
300+# Our Haskell model
301+
302+```haskell
303+type Parliament = [Group]
304+
305+data Group =
306+ Group { name :: Text
307+ , members :: [MemberOfParliament] }
308+
309+data MemberOfParliament =
310+ MemberOfParliament { firstName :: Text
311+ , lastName :: Text }
312+```
313+
314+> _note_ We didn't use anything from Squeal.
315+> The model can be entirely separated from the persistence layer.
316+
317+---
318+
319+# Inserting a Parliamentary Group
320+
321+- A group is very simple: it's a uuid and a name. Let's define our params:
322+
323+```haskell
324+type GroupInsertionParams = '[ 'NotNull 'PGuuid
325+ , 'NotNull 'PGtext ]
326+```
327+
328+- Params are not named, but they are indexed. You just need nullability and type.
329+
330+---
331+
332+```haskell
333+groupInsertion :: Manipulation Schema GroupInsertionParams '[]
334+groupInsertion =
335+ insertRow_ #groupp ( Set (param @1) `as` #groupp_id
336+ :* Set (param @2) `as` #name )
337+```
338+
339+---
340+
341+- `TypeApplication` lets us use the index of parameters (counting from 1).
342+
343+- Once again: all this is checked by the compiler. Wrong name, wrong type... you'll get a compile error.
344+
345+- `insertRow_` is a simplified version of `insertRow`. `insertRow` lets you express a `RETURNING` clause and the expected behaviour in case of conflict.
346+
347+---
348+
349+_Inserting a Member of Parliament_
350+# Doing an INSERT INTO ... SELECT
351+
352+- We could create a naive query that takes MP uuid, first name, last name and group uuid...
353+
354+---
355+
356+- But that's boring. So let's use the `INSERT INTO ... SELECT`.
357+
358+---
359+
360+- We will build a query that will return as constants our MP's uuid, first name and last name...
361+
362+---
363+
364+- ... and fetch the uuid of a group given the name of the group.
365+
366+---
367+
368+- There's a `insertQuery` utility function for that. All we have to do is write the `select` !
369+
370+```haskell
371+mpInsertion :: Manipulation Schema MpParams '[]
372+mpInsertion =
373+ insertQuery_ #mp selectGroup -- we just have to write selectGroup !
374+```
375+
376+---
377+
378+_Inserting a Member of Parliament_
379+# The query type
380+
381+- A query looks just like a `Manipulation`:
382+
383+```haskell
384+Query schema params returns
385+```
386+
387+- Returns use a special syntax, that demands names, nullability and types:
388+
389+```haskell
390+type ExampleReturnType = '[ "some_column" ::: 'NotNull 'PGuuid
391+ , "other_column" ::: 'Null 'PGtext ]
392+```
393+
394+- It is not the same as the column definition we used in the schema. That one also expects that you specify, for each column, an eventual default:
395+
396+```haskell
397+type ExampleSchemaCols =
398+ '[ "some_column" ::: 'NoDef :=> 'NotNull 'PGuuid
399+ , "other_column" ::: 'NoDef :=> 'Null 'PGtext ]
400+```
401+
402+---
403+
404+_Inserting a Member of Parliament_
405+# Don't rewrite column definitions
406+
407+- We want our return type to be "all columns from table MP expressed as return type".
408+
409+- But we cannot reuse our neat `MpCols` alias, since the type do not match as we've just seen.
410+
411+- Hopefully, there's a neat Type Family that will let you convert any table you defined to the type of the equivalent row: `TableToRow`.
412+
413+- We finally have the signature for our SELECT query.
414+
415+```haskell
416+selectGroup :: Query Schema MpParams (TableToRow MemberOfParliament)
417+```
418+
419+---
420+
421+_Inserting a Member of Parliament_
422+# Our final Select query
423+
424+- Our intermediate query looks like this:
425+
426+```haskell
427+selectGroup =
428+ select
429+ ( param @1 `as` #mp_id
430+ :* param @2 `as` #first_name
431+ :* param @3 `as` #last_name
432+ :* #groupp ! #groupp_id `as` #mp_group
433+ )
434+ ( from (table #groupp)
435+ & where_ ( #groupp ! #name .== param @4 )
436+ )
437+```
438+
439+- The first three columns are constant defined through our params;
440+
441+- ... we alias the column name using `as`...
442+
443+- ... and when we need the result from the table we use the `#table ! #column` syntax.
444+
445+- We'll go back to the "from" block later.
446+
447+---
448+
449+# Dealing with the connection context
450+
451+- Queries are runned in a connection context:
452+
453+ * When dealing with a single-connection context, use the type `PQ`.
454+
455+ * When dealing with a pool of connection, use the type `PoolPQ`.
456+
457+- Or get rid of the context and use `mtl` style, with the typeclass `MonadPQ`.
458+
459+- We'll use that to demonstrate how to actually run our queries.
460+
461+---
462+
463+# Inserting a whole group
464+
465+```haskell
466+insertGroup :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()
467+insertGroup g@(Group name _) = do
468+ uuid' <- liftBase nextRandom
469+ void $ manipulateParams groupInsertion (uuid', name)
470+ insertMps g
471+```
472+
473+- Remember that we defined a group as a name and a list of MPs.
474+
475+- We are in `MonadBaseControl`, so we cannot use `liftIO`, we need `liftBase`.
476+
477+- To perform a simple insertion, use `manipulateParams`. It takes into parameter
478+instances of `ToParam`, but you will typically use tuples or Generic-SOP.
479+
480+---
481+
482+# Inserting a bunch of MPs
483+
484+```haskell
485+insertMps :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()
486+insertMps (Group groupName mps) =
487+ let tuplify Mp{..} = (, firstName, lastName, groupName) <$> nextRandom
488+ params = traverse tuplify mps
489+ in void $ liftBase params >>= traversePrepared mpInsertion
490+```
491+
492+- This time, we want to do a `preparedStatement`. We'll use `traversePrepare`
493+which behaves like `manipulateParams`, but expect a list of `ToParam`
494+instances.
495+
496+- We build our tuple manually again, mostly because we want to generate UUID on
497+the fly and we don't want to have them in our model.
498+
499+---
500+
501+# Inserting a whole parliament
502+
503+```haskell
504+insertParliament ::
505+ (MonadPQ Schema m, MonadBaseControl IO m) => Parliament -> m ()
506+insertParliament = traverse_ insertGroup
507+```
508+
509+- That's simple enough !
510+
511+- If we want to be a bit safer, though, we can wrap this call in a
512+`transactionally_` function, which will put all that in a transaction.
513+
514+---
515+
516+![Very simple](https://media1.tenor.com/images/0188c63209aced59f1583e1ca94e509e/tenor.gif?itemid=3550689)
517+
518+
519+---
520+
521+# Part III. Selects
522+
523+---
524+
525+# Composable queries
526+
527+- Building basic queries is easy, and is well documented.
528+
529+- However, the real interest of a tool like Squeal is in DRYness, and the documentation is still lacking in "how-to" related to composability.
530+
531+- I'll build an example showing how column selections and from clause can be factorized.
532+
533+- We want to write two queries:
534+
535+ * One to get all members of a specific group.
536+
537+ * One to get all the parliament.
538+
539+---
540+
541+# Decomposing a `Query`
542+
543+- A query typically stars with `select` (variants are available).
544+
545+- It then takes:
546+
547+ * A heterogenous list of fields with a scary signature;
548+
549+ * A virtual table (the from clause and filter clauses), called a `TableExpression`.
550+
551+- And return fields. Ours will look like this:
552+
553+```haskell
554+type GroupRowResult =
555+ '[ "groupName" ::: 'NotNull 'PGtext
556+ , "firstName" ::: 'NotNull 'PGtext
557+ , "lastName" ::: 'NotNull 'PGtext ]
558+```
559+
560+---
561+
562+# The Table Expression
563+
564+- It necessarily contains a `fromClause` (table, view or subquery, plus optional joins).
565+
566+- You can add where, groups, "HAVING" clause, order, etc.
567+
568+- `from` creates a basic `TableExpression` that you extend through various function to add clauses.
569+
570+- For our queries, we will share a common `FromClause`.
571+
572+---
573+
574+# The From Clause
575+
576+```
577+FromClause schema params from
578+```
579+
580+- We need Schema, input parameters and a `FromType` giving the available fields of the expression.
581+
582+- In our case, we'll join the table `mp` and the table `groupp`, meaning the `from` will be all fields of these tables.
583+
584+- We can use `TableToRow` to be more DRY:
585+
586+```haskell
587+type BaseParliamentSelection =
588+ '[ "g" ::: TableToRow GroupCols
589+ , "m" ::: TableToRow MpCols ]
590+```
591+
592+> _note_ We've also put everything with table aliases: "g" and "m".
593+
594+---
595+
596+# Writing our from clause
597+
598+```haskell
599+baseParliamentTables ::
600+ FromClause Schema (param :: [NullityType]) BaseParliamentSelection
601+baseParliamentTables =
602+ table
603+ (#groupp `as` #g)
604+ & innerJoin
605+ (table (#mp `as` #m))
606+ (#m ! #mp_group .== #g ! #groupp_id)
607+```
608+
609+- When picking "from" something, you need to specify the type with a function: `table` for a table, `view` for a view, etc.
610+
611+- All joins are available. `innerJoin` is the most basic one. It takes the joined table and the joining condition.
612+
613+- We have to specifiy the type of `param` (current limitation of the lib), even though _any_ params will be compatible with this, so we can plug `where` clauses depending on params should we need to !
614+
615+---
616+
617+# Typing the common selection
618+
619+- Both our querie will need the same fields. This has to be factorized too.
620+
621+- The scary signature of selection fields:
622+
623+```haskell
624+NP (Aliased (Expression schema from grouping params)) cols
625+```
626+
627+- `NP` is for heterogenous lists ("n-ary product").
628+
629+- `from` is the virtual table type, so our `BaseParliamentSelection`.
630+
631+- `grouping` is there to make a distinction between aggregated / unaggregated queries.
632+
633+- And finally, cols is the return type.
634+
635+---
636+
637+# Our common selection
638+
639+```haskell
640+groupSelection ::
641+ NP (Aliased (Expression Schema BaseParliamentSelection 'Ungrouped param))
642+ GroupRowResult
643+groupSelection =
644+ #g ! #name `as` #groupName
645+ :* #m ! #first_name `as` #firstName
646+ :* #m ! #last_name `as` #lastName
647+```
648+
649+- I hope you like big signatures.
650+
651+- But it's what let GHC checks that all alias and columns are available.
652+
653+- And that you're returning what you really intend to return.
654+
655+---
656+
657+# Putting it all together
658+
659+```haskell
660+selectParliament :: Query Schema '[] GroupRowResult
661+selectParliament =
662+ select groupSelection (from baseParliamentTables)
663+```
664+
665+```haskell
666+selectGroupMembers :: Query Schema '[ 'NotNull 'PGtext] GroupRowResult
667+selectGroupMembers =
668+ select groupSelection
669+ (from baseParliamentTables
670+ & where_ (#g ! #name .== param @1))
671+```
672+
673+- That is fairly DRY. And _entirely typesafe_.
674+
675+---
676+
677+# Actually fetching the data
678+
679+- We'll build an intermediary datatype representing our rows.
680+
681+- We'll make it match our row.
682+
683+- And we'll add generic-SOP so that we can build them from query results.
684+
685+```haskell
686+type GroupRowResult =
687+ '[ "groupName" ::: 'NotNull 'PGtext
688+ , "firstName" ::: 'NotNull 'PGtext
689+ , "lastName" ::: 'NotNull 'PGtext ]
690+```
691+
692+```haskell
693+data GroupRow =
694+ GroupRow { groupName :: Text
695+ , firstName :: Text
696+ , lastName :: Text }
697+ deriving (Generic)
698+
699+instance SOP.Generic GroupRow
700+instance SOP.HasDatatypeInfo GroupRow
701+```
702+
703+---
704+
705+# Aggregate result logic
706+
707+- We will get tabular, SQL data.
708+
709+- Our results will be `[GroupRow]`.
710+
711+- We'll build `Groups` from this:
712+
713+```haskell
714+buildGroup :: NE.NonEmpty GroupRow -> Group
715+buildGroup grs =
716+ let buildMP (GroupRow _ f l) = Mp f l
717+ name = groupName . NE.head $ grs
718+ members = NE.toList (buildMP <$> grs)
719+ in Group{..}
720+
721+rowToGroups :: [GroupRow] -> [Group]
722+rowToGroups =
723+ let grouped = fmap NE.fromList . L.groupBy ((==) `on` groupName)
724+ in fmap buildGroup . grouped
725+```
726+
727+---
728+
729+# Finally calling our queries
730+
731+- Query with params will use `runQueryParams`.
732+
733+- Query without params will use `runQuery`.
734+
735+- Result is inside a `MonadPQ` and of type `K` from generic-sop.
736+
737+- You get your actual result using `getRows`. Exemple:
738+
739+```haskell
740+getParliament :: (MonadPQ Schema m, MonadBaseControl IO m) => m [Group]
741+getParliament = do
742+ res <- runQuery selectParliament
743+ rows <- getRows res
744+ pure $ rowToGroups rows
745+```
746+
747+- In real life of course you'll write:
748+
749+```haskell
750+getParliament =
751+ rowToGroups <$> (runQuery selectParliament >>= getRows)
752+```
753+
754+---
755+
756+# Our query with params
757+
758+```haskell
759+getGroupMembers ::
760+ (MonadPQ Schema m, MonadBaseControl IO m) => Text -> m (Maybe Group)
761+getGroupMembers =
762+ listToMaybe . rowToGroups <$>
763+ (runQueryParams selectGroupMembers (Only t) >>= getRows)
764+```
765+
766+- And that's it.
767+
768+---
769+
770+![Eazy](https://media.tenor.com/images/8fc7c4077efe11b4a3a3b9ae4e643e87/tenor.gif)
771+
772+---
773+
774+# Conclusion
775+
776+---
777+
778+# Pros & Cons
779+
780+- Not everything is included: some cool stuff like array_agg and window functions are not available yet.
781+
782+- But development is _very_ active. `IN` clauses were missing but were added in the 4.0 released recently.
783+
784+- It's bleeding edge. You need latest LTS to be comfortable and psql >= 9.5.
785+
786+- It's Postgres-only but I would say that's a feature. Multi-DB tools are even more complex.
787+
788+- The author & maintainer is <3.
789+
790+- Typesafe. 'nuff said.
791+
792+---
793+
794+# Thank you !
stack.yaml+6−1
@@ -1,3 +1,8 @@
1−resolver: lts-11.15
1+resolver: nightly-2019-07-14
2packages:
2packages:
3- squeal-postgresql
3- squeal-postgresql
4+
5+extra-deps:
6+- unliftio-pool-0.2.1.0
7+- github: morphismtech/free-categories
8+ commit: c0e555fbefb5c21619e532264c4dfeac556d0630