git.iko.soy/squeal
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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:latest
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+177−126
@@ -10,25 +10,80 @@
10
10
11[Stackage](https://www.stackage.org/package/squeal-postgresql)
11[Stackage](https://www.stackage.org/package/squeal-postgresql)
12
12
13+[YouTube](https://www.youtube.com/watch?v=rWfEQfAaNc4)
14+
15+## introduction
16+
17+Squeal is a deep embedding of SQL into Haskell. By "deep embedding", I am abusing the
18+term somewhat. What I mean is that Squeal embeds both SQL terms and SQL types
19+into Haskell at the term and type levels respectively. This leads to a very high level
20+of type-safety in Squeal.
21+
22+Squeal embeds not just the structured query language of SQL but also the
23+data manipulation language and the data definition language; that's `SELECT`,
24+`INSERT`, `UPDATE`, `DELETE`, `WITH`, `CREATE`, `DROP`, and `ALTER` commands.
25+
26+Squeal expressions closely match their corresponding SQL expressions so that
27+the SQL they actually generate is completely predictable. They are also highly
28+composable and cover a large portion of SQL.
29+
30+## features
31+
32+* generic encoding of Haskell tuples and records into query parameters
33+ and generic decoding of query results into Haskell records
34+ using [`generics-sop`](https://hackage.haskell.org/package/generics-sop)
35+* access to SQL alias system using the `OverloadedLabels` extension
36+* type-safe `NULL` and `DEFAULT`
37+* type-safe SQL constraints `CHECK`, `UNIQUE`, `PRIMARY KEY` and `FOREIGN KEY`
38+* type-safe aggregation
39+* escape hatches for writing raw SQL
40+* [`mtl`](https://hackage.haskell.org/package/mtl) compatible monad transformer
41+ for executing as well as preparing queries and manipulations
42+ and [Atkey](https://bentnib.org/paramnotions-jfp.pdf) indexed monad transformer
43+ for executing definitions.
44+* linear, invertible migrations
45+* connection pools
46+* transactions
47+* views
48+* array, composite and enumerated types
49+* json functions and operations
50+* multischema support
51+* correlated subqueries
52+* window functions
53+* text search
54+
13## installation
55## installation
14
56
15`stack install squeal-postgresql`
57`stack install squeal-postgresql`
16
58
59+## testing
60+
61+Start postgres on localhost port `5432` and create a database named `exampledb`.
62+
63+`stack test`
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+
17## usage
71## usage
18
72
19−Squeal is a deep embedding of PostgreSQL in Haskell. Let's see an example!
73+Let's see an example!
74+
20First, we need some language extensions because Squeal uses modern GHC
75First, we need some language extensions because Squeal uses modern GHC
21features.
76features.
22−```haskell
77+
78+```Haskell
23−>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels
79+>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels -XFlexibleContexts
24−>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators
80+>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators -XGADTs
25```
81```
26
82
27We'll need some imports.
83We'll need some imports.
28
84
29−```haskell
85+```Haskell
30−>>> import Control.Monad (void)
86+>>> import Control.Monad.IO.Class (liftIO)
31−>>> import Control.Monad.Base (liftBase)
32>>> import Data.Int (Int32)
87>>> import Data.Int (Int32)
33>>> import Data.Text (Text)
88>>> import Data.Text (Text)
34>>> import Squeal.PostgreSQL
89>>> import Squeal.PostgreSQL
@@ -36,165 +91,163 @@ We'll need some imports.
36
91
37We'll use generics to easily convert between Haskell and PostgreSQL values.
92We'll use generics to easily convert between Haskell and PostgreSQL values.
38
93
39−```haskell
94+```Haskell
40>>> import qualified Generics.SOP as SOP
95>>> import qualified Generics.SOP as SOP
41>>> import qualified GHC.Generics as GHC
96>>> import qualified GHC.Generics as GHC
42```
97```
43
98
44The first step is to define the schema of our database. This is where
99The first step is to define the schema of our database. This is where
45−we use `DataKinds` and `TypeOperators`. The schema consists of a type-level
100+we use `DataKinds` and `TypeOperators`.
46−list of tables, a `:::` pairing of a type level string or
101+
47−`Symbol` and a list a columns, itself a `:::` pairing of a
102+```Haskell
48−`Symbol` and a `ColumnType`. The `ColumnType` describes the
49−PostgreSQL type of the column as well as whether or not it may contain
50−`NULL` and whether or not inserts and updates can use a `DEFAULT`. For our
51−schema, we'll define two tables, a users table and an emails table.
52−
53−```haskell
54>>> :{
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"] ]
55type Schema =
115type Schema =
56− '[ "users" :::
116+ '[ "users" ::: 'Table (UsersConstraints :=> UsersColumns)
57− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
117+ , "emails" ::: 'Table (EmailsConstraints :=> EmailsColumns) ]
58− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
118+type Schemas = Public Schema
59− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
60− ]
61− , "emails" :::
62− '[ "pk_emails" ::: 'PrimaryKey '["id"]
63− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
64− ] :=>
65− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
66− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
67− , "email" ::: 'NoDef :=> 'Null 'PGtext
68− ]
69− ]
70:}
119:}
71```
120```
72
121
122+Notice the use of type operators.
123+
124+`:::` is used to pair an alias `Symbol` with a `SchemumType`,
125+a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's `::`
126+operator.
127+
128+`:=>` is used to pair `TableConstraints` with a `ColumnsType`,
129+yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,
130+yielding a `ColumnType`. It is intended to connote Haskell's `=>` operator
131+
73Next, 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
74−Squeal, a `Definition` is a `createTable`, `alterTable` or `dropTable`
133+Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`
75−command and has two type parameters, corresponding to the schema
134+has two type parameters, corresponding to the schema
76−before being run and the schema after. We can compose definitions using
135+before being run and the schema after. We can compose definitions using `>>>`.
77−`>>>`. Here and in the rest of our commands we make use of overloaded
136+Here and in the rest of our commands we make use of overloaded
78labels to refer to named tables and columns in our schema.
137labels to refer to named tables and columns in our schema.
79
138
80−```haskell
139+```Haskell
81>>> :{
140>>> :{
82let
141let
83− setup :: Definition '[] Schema
142+ setup :: Definition (Public '[]) Schemas
84− setup =
143+ setup =
85− createTable #users
144+ createTable #users
86− ( serial `As` #id :*
145+ ( serial `as` #id :*
87− (text & notNull) `As` #name :* Nil )
146+ (text & notNullable) `as` #name )
88− ( primaryKey (Column #id :* Nil) `As` #pk_users :* Nil ) >>>
147+ ( primaryKey #id `as` #pk_users ) >>>
89− createTable #emails
148+ createTable #emails
90− ( serial `As` #id :*
149+ ( serial `as` #id :*
91− (int & notNull) `As` #user_id :*
150+ (int & notNullable) `as` #user_id :*
92− text `As` #email :* Nil )
151+ (text & nullable) `as` #email )
93− ( primaryKey (Column #id :* Nil) `As` #pk_emails :*
152+ ( primaryKey #id `as` #pk_emails :*
94− foreignKey (Column #user_id :* Nil) #users (Column #id :* Nil)
153+ foreignKey #user_id #users #id
95− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
154+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
96:}
155:}
97```
156```
98
157
99−We can easily see the generated SQL is unsuprising looking.
158+We can easily see the generated SQL is unsurprising looking.
100
159
101−```haskell
160+```Haskell
102−>>> renderDefinition setup
161+>>> printSQL setup
162+CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));
103−"CREATE TABLE users (id serial, name text NOT NULL, CONSTRAINT pk_users PRIMARY KEY (id)); CREATE TABLE emails (id serial, user_id int NOT NULL, email text, CONSTRAINT pk_emails PRIMARY KEY (id), CONSTRAINT fk_user_id FOREIGN KEY (user_id) REFERENCES rs (id) ON DELETE CASCADE ON UPDATE CASCADE);"
163+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);
104```
164```
105
165
106Notice that `setup` starts with an empty schema `'[]` and produces `Schema`.
166Notice that `setup` starts with an empty schema `'[]` and produces `Schema`.
107In our `createTable` commands we included `TableConstraint`s to define
167In our `createTable` commands we included `TableConstraint`s to define
108−primary and foreign keys, making them somewhat complex. Our tear down
168+primary and foreign keys, making them somewhat complex. Our `teardown`
109`Definition` is simpler.
169`Definition` is simpler.
110
170
111−```haskell
171+```Haskell
112>>> :{
172>>> :{
113let
173let
114− teardown :: Definition Schema '[]
174+ teardown :: Definition Schemas (Public '[])
115 teardown = dropTable #emails >>> dropTable #users
175 teardown = dropTable #emails >>> dropTable #users
116:}
176:}
177+
117−>>> renderDefinition teardown
178+>>> printSQL teardown
118−"DROP TABLE emails; DROP TABLE users;"
179+DROP TABLE "emails";
180+DROP TABLE "users";
119```
181```
120
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+
121−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.
122−A `Manipulation` is a `insertInto`, `update` or `deleteFrom` command and
193+A `Manipulation_` like `insertInto`, `update` or `deleteFrom`
123−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
124−it can take as input, and a list of columns it produces as output. When
195+and an output row. When
125we 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`
126−field but not for the `id` field. Since it's optional, we can use a default
197+field but not for the `id` field. Since it's serial, we can use a default
127value. 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
128need 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
129−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
130−of our inserts.
201+`with` statement.
131
202
132−```haskell
203+```Haskell
133>>> :{
204>>> :{
134let
205let
135− insertUser :: Manipulation Schema '[ 'NotNull 'PGtext ]
206+ insertUser :: Manipulation_ Schemas User ()
136− '[ "fromOnly" ::: 'NotNull 'PGint4 ]
207+ insertUser = with (u `as` #u) e
137− insertUser = insertRow #users
208+ where
209+ u = insertInto #users
138− (Default `As` #id :* Set (param `1) `As` #name :* Nil)
210+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))
139− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))
211+ OnConflictDoRaise (Returning_ (#id :* param @2 `as` #email))
212+ e = insertInto_ #emails $ Select
213+ (Default `as` #id :* Set (#u ! #id) `as` #user_id :* Set (#u ! #email) `as` #email)
214+ (from (common #u))
140:}
215:}
141−>>> :{
216+
142−let
143− insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]
144− insertEmail = insertRow #emails
145− ( Default `As` #id :*
146− Set (param `1) `As` #user_id :*
147− Set (param `2) `As` #email :* Nil )
148− OnConflictDoNothing (Returning Nil)
149−:}
150−>>> renderManipulation insertUser
217+>>> printSQL insertUser
151−"INSERT INTO users (id, name) VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING URNING 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"
152−>>> renderManipulation insertEmail
153−"INSERT INTO emails (id, user_id, email) VALUES (DEFAULT, ($1 :: int4), ($2 :: text)N CONFLICT DO NOTHING;"
154```
219```
155
220
156−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
157interested in the ids here, just the usernames and email addresses. We
222interested in the ids here, just the usernames and email addresses. We
158−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
159−`Manipulation` with the same kind of type parameters.
224+`Manipulation_` with the same kind of type parameters.
160
225
161−```haskell
226+```Haskell
162>>> :{
227>>> :{
163let
228let
164− getUsers :: Query Schema '[]
229+ getUsers :: Query_ Schemas () User
165− '[ "userName" ::: 'NotNull 'PGtext
166− , "userEmail" ::: 'Null 'PGtext ]
167− getUsers = select
230+ getUsers = select_
168− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* Nil)
231+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail)
169− ( from (table (#users `As` #u)
232+ ( from (table (#users `as` #u)
170− & innerJoin (table (#emails `As` #e))
233+ & innerJoin (table (#emails `as` #e))
171 (#u ! #id .== #e ! #user_id)) )
234 (#u ! #id .== #e ! #user_id)) )
172:}
235:}
236+
173−>>> renderQuery getUsers
237+>>> printSQL getUsers
174−"SELECT u.name AS userName, e.email AS userEmail FROM users AS u INNER JOIN emails e ON (u.id = e.user_id)"
238+SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")
175−```
176−Now that we've defined the SQL side of things, we'll need a Haskell type
177−for users. We give the type `Generics.SOP.Generic` and
178−`Generics.SOP.HasDatatypeInfo` instances so that we can decode the rows
179−we receive when we run `getUsers`. Notice that the record fields of the
180−`User` type match the column names of `getUsers`.
181−
182−```haskell
183−>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, .Generic)
184−>>> instance SOP.Generic User
185−>>> instance SOP.HasDatatypeInfo User
186```
239```
187
240
188−Let's also create some users to add to the database.
241+Let's create some users to add to the database.
189
242
190−```haskell
243+```Haskell
191>>> :{
244>>> :{
192let
245let
193 users :: [User]
246 users :: [User]
194− users =
247+ users =
195− [ User "Alice" (Just "alice`gmail.com")
248+ [ User "Alice" (Just "alice@gmail.com")
196 , User "Bob" Nothing
249 , User "Bob" Nothing
197− , User "Carole" (Just "carole`hotmail.com")
250+ , User "Carole" (Just "carole@hotmail.com")
198 ]
251 ]
199:}
252:}
200```
253```
@@ -207,23 +260,21 @@ the changing schema information through by using the indexed `PQ` monad
207transformer and when the schema doesn't change we can use `Monad` and
260transformer and when the schema doesn't change we can use `Monad` and
208`MonadPQ` functionality.
261`MonadPQ` functionality.
209
262
210−```haskell
263+```Haskell
211>>> :{
264>>> :{
212let
265let
213− session :: PQ Schema Schema IO ()
266+ session :: PQ Schemas Schemas IO ()
214 session = do
267 session = do
215− idResults <- traversePrepared insertUser (Only . userName <$> users)
268+ _ <- traversePrepared_ insertUser users
216− ids <- traverse (fmap fromOnly . getRow (RowNumber 0)) idResults
217− traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))
218 usersResult <- runQuery getUsers
269 usersResult <- runQuery getUsers
219 usersRows <- getRows usersResult
270 usersRows <- getRows usersResult
220− liftBase $ print (usersRows :: [User])
271+ liftIO $ print (usersRows :: [User])
221−:}
272+in
222−>>> :{
223−void . withConnection "host=localhost port=5432 dbname=exampledb" $
273+ withConnection "host=localhost port=5432 dbname=exampledb" $
224− define setup
274+ define setup
225− & pqThen session
275+ & pqThen session
226− & thenDefine teardown
276+ & pqThen (define teardown)
227:}
277:}
228−[User {userName = "Alice", userEmail = Just "alice`gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just role`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+-}
229```
280```
RELEASE NOTES.md+1084−1
@@ -1,6 +1,1089 @@
1## RELEASE NOTES
1## RELEASE NOTES
2
2
3−### Version 0.2 - March 24, 2018
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+
840+### Version 0.3 - June 26, 2018
841+
842+Version 0.3 of Squeal adds views as well as composite and enumerated types to Squeal.
843+To support these features, a new kind `SchemumType` was added.
844+
845+```Haskell
846+data SchemumType
847+ = Table TableType
848+ | View RelationType
849+ | Typedef PGType
850+```
851+
852+As a consequence, you will have to update your schema definitions like so:
853+
854+```Haskell
855+-- Squeal 0.2
856+type Schema =
857+ '[ "users" :::
858+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
859+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
860+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
861+ ]
862+ ]
863+
864+-- Squeal 0.3
865+type Schema =
866+ '[ "users" ::: 'Table (
867+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
868+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
869+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
870+ ])
871+ ]
872+```
873+
874+**Views**
875+
876+You can now create, drop, and query views.
877+
878+```Haskell
879+>>> :{
880+type ABC =
881+ ('[] :: TableConstraints) :=>
882+ '[ "a" ::: 'NoDef :=> 'Null 'PGint4
883+ , "b" ::: 'NoDef :=> 'Null 'PGint4
884+ , "c" ::: 'NoDef :=> 'Null 'PGint4
885+ ]
886+type BC =
887+ '[ "b" ::: 'Null 'PGint4
888+ , "c" ::: 'Null 'PGint4
889+ ]
890+:}
891+
892+>>> :{
893+let
894+ definition :: Definition '["abc" ::: 'Table ABC ] '["abc" ::: 'Table ABC, "bc" ::: 'View BC]
895+ definition = createView #bc (select (#b :* #c :* Nil) (from (table #abc)))
896+in printSQL definition
897+:}
898+CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";
899+
900+>>> :{
901+let
902+ definition :: Definition '["abc" ::: 'Table ABC, "bc" ::: 'View BC] '["abc" ::: 'Table ABC]
903+ definition = dropView #bc
904+in printSQL definition
905+:}
906+DROP VIEW "bc";
907+
908+>>> :{
909+let
910+ query :: Query '["abc" ::: 'Table ABC, "bc" ::: 'View BC] '[] BC
911+ query = selectStar (from (view #bc))
912+in printSQL query
913+:}
914+SELECT * FROM "bc" AS "bc"
915+```
916+
917+**Enumerated Types**
918+
919+PostgreSQL has a powerful type system. It even allows for user defined types.
920+For instance, you can define enumerated types which are data types that comprise
921+a static, ordered set of values. They are equivalent to Haskell algebraic data
922+types whose constructors are nullary. An example of an enum type might be the days of the week,
923+or a set of status values for a piece of data.
924+
925+Enumerated types are created using the `createTypeEnum` command, for example:
926+
927+```Haskell
928+>>> :{
929+let
930+ definition :: Definition '[] '["mood" ::: 'Typedef ('PGenum '["sad", "ok", "happy"])]
931+ definition = createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy" :* Nil)
932+:}
933+>>> printSQL definition
934+CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');
935+```
936+
937+Enumerated types can also be generated from a Haskell algebraic data type with nullary constructors, for example:
938+
939+```Haskell
940+>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
941+>>> instance SOP.Generic Schwarma
942+>>> instance SOP.HasDatatypeInfo Schwarma
943+
944+>>> :kind! EnumFrom Schwarma
945+EnumFrom Schwarma :: PGType
946+= 'PGenum '["Beef", "Lamb", "Chicken"]
947+
948+>>> :{
949+let
950+ definition :: Definition '[] '["schwarma" ::: 'Typedef (EnumFrom Schwarma)]
951+ definition = createTypeEnumFrom @Schwarma #schwarma
952+:}
953+>>> printSQL definition
954+CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');
955+```
956+
957+You can express values of an enum type using `label`, which is an overloaded method
958+of the `IsPGlabel` typeclass.
959+
960+```Haskell
961+>>> :{
962+let
963+ expression :: Expression sch rels grp params ('NotNull (EnumFrom Schwarma))
964+ expression = label @"Chicken"
965+in printSQL expression
966+:}
967+'Chicken'
968+```
969+
970+**Composite Types**
971+
972+In addition to enum types, you can define composite types.
973+A composite type represents the structure of a row or record;
974+it is essentially just a list of field names and their data types.
975+
976+
977+`createTypeComposite` creates a composite type. The composite type is
978+specified by a list of attribute names and data types.
979+
980+```Haskell
981+>>> :{
982+let
983+ definition :: Definition '[] '["complex" ::: 'Typedef ('PGcomposite '["real" ::: 'PGfloat8, "imaginary" ::: 'PGfloat8])]
984+ definition = createTypeComposite #complex (float8 `As` #real :* float8 `As` #imaginary :* Nil)
985+:}
986+>>> printSQL definition
987+CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
988+```
989+
990+Composite types are almost equivalent to Haskell record types.
991+However, because of the potential presence of `NULL`
992+all the record fields must be `Maybe`s of basic types.
993+Composite types can be generated from a Haskell record type, for example:
994+
995+```Haskell
996+>>> data Complex = Complex {real :: Maybe Double, imaginary :: Maybe Double} deriving GHC.Generic
997+>>> instance SOP.Generic Complex
998+>>> instance SOP.HasDatatypeInfo Complex
999+
1000+>>> :kind! CompositeFrom Complex
1001+CompositeFrom Complex :: PGType
1002+= 'PGcomposite '['("real", 'PGfloat8), '("imaginary", 'PGfloat8)]
1003+
1004+>>> :{
1005+let
1006+ definition :: Definition '[] '["complex" ::: 'Typedef (CompositeFrom Complex)]
1007+ definition = createTypeCompositeFrom @Complex #complex
1008+in printSQL definition
1009+:}
1010+CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
1011+```
1012+
1013+A row constructor is an expression that builds a row value
1014+(also called a composite value) using values for its member fields.
1015+
1016+```Haskell
1017+>>> :{
1018+let
1019+ i :: Expression '[] '[] 'Ungrouped '[] ('NotNull (CompositeFrom Complex))
1020+ i = row (0 `As` #real :* 1 `As` #imaginary :* Nil)
1021+:}
1022+>>> printSQL i
1023+ROW(0, 1)
1024+```
1025+
1026+You can also use `(&)` to apply a field label to a composite value.
1027+
1028+```Haskell
1029+>>> :{
1030+let
1031+ expr :: Expression '[] '[] 'Ungrouped '[] ('Null 'PGfloat8)
1032+ expr = i & #imaginary
1033+in printSQL expr
1034+:}
1035+(ROW(0, 1)).imaginary
1036+```
1037+
1038+Both composite and enum types can be automatically encoded from and decoded to their equivalent Haskell types.
1039+And they can be dropped.
1040+
1041+```Haskell
1042+>>> :{
1043+let
1044+ definition :: Definition '["mood" ::: 'Typedef ('PGenum '["sad", "ok", "happy"])] '[]
1045+ definition = dropType #mood
1046+:}
1047+>>> printSQL definition
1048+DROP TYPE "mood";
1049+```
1050+
1051+**Additional Changes**
1052+
1053+Squeal 0.3 also introduces a typeclass `HasAll` similar to `Has` but for a list of aliases.
1054+This makes it possible to clean up some unfortunately messy Squeal 0.2 definitions.
1055+
1056+```Haskell
1057+-- Squeal 0.2
1058+>>> unique (Column #a :* Column #b :* Nil)
1059+
1060+-- Squeal 0.3
1061+>>> unique (#a :* #b :* Nil)
1062+```
1063+
1064+Squeal 0.3 also adds `IsLabel` instances for `Aliased` expressions and tables as well as
1065+heterogeneous lists, allowing for some more economy of code.
1066+
1067+```Haskell
1068+-- Squeal 0.2 (or 0.3)
1069+>>> select (#a `As` #a :* Nil) (from (table (#t `As` #t)))
1070+
1071+-- Squeal 0.3
1072+>>> select #a (from (table #t))
1073+```
1074+
1075+Squeal 0.3 also fixes a bug that prevented joined queries on self-referencing tables.
1076+
1077+The above changes required major and minor changes to Squeal DSL functions.
1078+Please consult the documentation.
1079+
1080+### Version 0.2.1 - April 7, 2018
1081+
1082+This minor update fixes an issue where alias identifiers could conflict with
1083+reserved words in PostgreSQL. To fix the issue, alias identifiers are now
1084+quoted. Thanks to Petter Rasmussen for the fix.
1085+
1086+### Version 0.2 - March 26, 2018
4
1087
5**Changes**
1088**Changes**
6- **Constraints** - Type level table constraints like primary and foreign keys and column constraints like having `DEFAULT`.
1089- **Constraints** - Type level table constraints like primary and foreign keys and column constraints like having `DEFAULT`.
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/README.md+1−219
@@ -1,4 +1,4 @@
1−# squeal
1+# squeal-postgresql
2
2
3![squeal-icon](http://www.emoticonswallpapers.com/emotion/cute-big-pig/cute-pig-smiley-046.gif)
3![squeal-icon](http://www.emoticonswallpapers.com/emotion/cute-big-pig/cute-pig-smiley-046.gif)
4
4
@@ -9,221 +9,3 @@
9[Hackage](https://hackage.haskell.org/package/squeal-postgresql)
9[Hackage](https://hackage.haskell.org/package/squeal-postgresql)
10
10
11[Stackage](https://www.stackage.org/package/squeal-postgresql)
11[Stackage](https://www.stackage.org/package/squeal-postgresql)
12−
13−## installation
14−
15−`stack install squeal-postgresql`
16−
17−## usage
18−
19−Squeal is a deep embedding of PostgreSQL in Haskell. Let's see an example!
20−First, we need some language extensions because Squeal uses modern GHC
21−features.
22−```haskell
23−>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels
24−>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators
25−```
26−
27−We'll need some imports.
28−
29−```haskell
30−>>> import Control.Monad (void)
31−>>> import Control.Monad.Base (liftBase)
32−>>> import Data.Int (Int32)
33−>>> import Data.Text (Text)
34−>>> import Squeal.PostgreSQL
35−```
36−
37−We'll use generics to easily convert between Haskell and PostgreSQL values.
38−
39−```haskell
40−>>> import qualified Generics.SOP as SOP
41−>>> import qualified GHC.Generics as GHC
42−```
43−
44−The first step is to define the schema of our database. This is where
45−we use `DataKinds` and `TypeOperators`. The schema consists of a type-level
46−list of tables, a `:::` pairing of a type level string or
47−`Symbol` and a list a columns, itself a `:::` pairing of a
48−`Symbol` and a `ColumnType`. The `ColumnType` describes the
49−PostgreSQL type of the column as well as whether or not it may contain
50−`NULL` and whether or not inserts and updates can use a `DEFAULT`. For our
51−schema, we'll define two tables, a users table and an emails table.
52−
53−```haskell
54−>>> :{
55−type Schema =
56− '[ "users" :::
57− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
58− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
59− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
60− ]
61− , "emails" :::
62− '[ "pk_emails" ::: 'PrimaryKey '["id"]
63− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
64− ] :=>
65− '[ "id" ::: 'Def :=> 'NotNull 'PGint4
66− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
67− , "email" ::: 'NoDef :=> 'Null 'PGtext
68− ]
69− ]
70−:}
71−```
72−
73−Next, we'll write `Definition`s to set up and tear down the schema. In
74−Squeal, a `Definition` is a `createTable`, `alterTable` or `dropTable`
75−command and has two type parameters, corresponding to the schema
76−before being run and the schema after. We can compose definitions using
77−`>>>`. Here and in the rest of our commands we make use of overloaded
78−labels to refer to named tables and columns in our schema.
79−
80−```haskell
81−>>> :{
82−let
83− setup :: Definition '[] Schema
84− setup =
85− createTable #users
86− ( serial `As` #id :*
87− (text & notNull) `As` #name :* Nil )
88− ( primaryKey (Column #id :* Nil) `As` #pk_users :* Nil ) >>>
89− createTable #emails
90− ( serial `As` #id :*
91− (int & notNull) `As` #user_id :*
92− text `As` #email :* Nil )
93− ( primaryKey (Column #id :* Nil) `As` #pk_emails :*
94− foreignKey (Column #user_id :* Nil) #users (Column #id :* Nil)
95− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
96−:}
97−```
98−
99−We can easily see the generated SQL is unsuprising looking.
100−
101−```haskell
102−>>> renderDefinition setup
103−"CREATE TABLE users (id serial, name text NOT NULL, CONSTRAINT pk_users PRIMARY KEY (id)); CREATE TABLE emails (id serial, user_id int NOT NULL, email text, CONSTRAINT pk_emails PRIMARY KEY (id), CONSTRAINT fk_user_id FOREIGN KEY (user_id) REFERENCES rs (id) ON DELETE CASCADE ON UPDATE CASCADE);"
104−```
105−
106−Notice that `setup` starts with an empty schema `'[]` and produces `Schema`.
107−In our `createTable` commands we included `TableConstraint`s to define
108−primary and foreign keys, making them somewhat complex. Our tear down
109−`Definition` is simpler.
110−
111−```haskell
112−>>> :{
113−let
114− teardown :: Definition Schema '[]
115− teardown = dropTable #emails >>> dropTable #users
116−:}
117−>>> renderDefinition teardown
118−"DROP TABLE emails; DROP TABLE users;"
119−```
120−
121−Next, we'll write `Manipulation`s to insert data into our two tables.
122−A `Manipulation` is a `insertInto`, `update` or `deleteFrom` command and
123−has three type parameters, the schema it refers to, a list of parameters
124−it can take as input, and a list of columns it produces as output. When
125−we insert into the users table, we will need a parameter for the `name`
126−field but not for the `id` field. Since it's optional, we can use a default
127−value. However, since the emails table refers to the users table, we will
128−need to retrieve the user id that the insert generates and insert it into
129−the emails table. Take a careful look at the type and definition of both
130−of our inserts.
131−
132−```haskell
133−>>> :{
134−let
135− insertUser :: Manipulation Schema '[ 'NotNull 'PGtext ]
136− '[ "fromOnly" ::: 'NotNull 'PGint4 ]
137− insertUser = insertRow #users
138− (Default `As` #id :* Set (param `1) `As` #name :* Nil)
139− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))
140−:}
141−>>> :{
142−let
143− insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]
144− insertEmail = insertRow #emails
145− ( Default `As` #id :*
146− Set (param `1) `As` #user_id :*
147− Set (param `2) `As` #email :* Nil )
148− OnConflictDoNothing (Returning Nil)
149−:}
150−>>> renderManipulation insertUser
151−"INSERT INTO users (id, name) VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING URNING id AS fromOnly;"
152−>>> renderManipulation insertEmail
153−"INSERT INTO emails (id, user_id, email) VALUES (DEFAULT, ($1 :: int4), ($2 :: text)N CONFLICT DO NOTHING;"
154−```
155−
156−Next we write a `Query` to retrieve users from the database. We're not
157−interested in the ids here, just the usernames and email addresses. We
158−need to use an inner join to get the right result. A `Query` is like a
159−`Manipulation` with the same kind of type parameters.
160−
161−```haskell
162−>>> :{
163−let
164− getUsers :: Query Schema '[]
165− '[ "userName" ::: 'NotNull 'PGtext
166− , "userEmail" ::: 'Null 'PGtext ]
167− getUsers = select
168− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* Nil)
169− ( from (table (#users `As` #u)
170− & innerJoin (table (#emails `As` #e))
171− (#u ! #id .== #e ! #user_id)) )
172−:}
173−>>> renderQuery getUsers
174−"SELECT u.name AS userName, e.email AS userEmail FROM users AS u INNER JOIN emails e ON (u.id = e.user_id)"
175−```
176−Now that we've defined the SQL side of things, we'll need a Haskell type
177−for users. We give the type `Generics.SOP.Generic` and
178−`Generics.SOP.HasDatatypeInfo` instances so that we can decode the rows
179−we receive when we run `getUsers`. Notice that the record fields of the
180−`User` type match the column names of `getUsers`.
181−
182−```haskell
183−>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, .Generic)
184−>>> instance SOP.Generic User
185−>>> instance SOP.HasDatatypeInfo User
186−```
187−
188−Let's also create some users to add to the database.
189−
190−```haskell
191−>>> :{
192−let
193− users :: [User]
194− users =
195− [ User "Alice" (Just "alice`gmail.com")
196− , User "Bob" Nothing
197− , User "Carole" (Just "carole`hotmail.com")
198− ]
199−:}
200−```
201−
202−Now we can put together all the pieces into a program. The program
203−connects to the database, sets up the schema, inserts the user data
204−(using prepared statements as an optimization), queries the user
205−data and prints it out and finally closes the connection. We can thread
206−the changing schema information through by using the indexed `PQ` monad
207−transformer and when the schema doesn't change we can use `Monad` and
208−`MonadPQ` functionality.
209−
210−```haskell
211−>>> :{
212−let
213− session :: PQ Schema Schema IO ()
214− session = do
215− idResults <- traversePrepared insertUser (Only . userName <$> users)
216− ids <- traverse (fmap fromOnly . getRow (RowNumber 0)) idResults
217− traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))
218− usersResult <- runQuery getUsers
219− usersRows <- getRows usersResult
220− liftBase $ print (usersRows :: [User])
221−:}
222−>>> :{
223−void . withConnection "host=localhost port=5432 dbname=exampledb" $
224− define setup
225− & pqThen session
226− & thenDefine teardown
227−:}
228−[User {userName = "Alice", userEmail = Just "alice`gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just role`hotmail.com"}]
229−```
squeal-postgresql/exe/Example.hs+51−54
@@ -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)
@@ -25,86 +24,84 @@ import qualified Generics.SOP as SOP
25import qualified GHC.Generics as GHC
24import qualified GHC.Generics as GHC
26
25
27type Schema =
26type Schema =
28− '[ "users" :::
27+ '[ "users" ::: 'Table (
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" :::
33+ , "emails" ::: 'Table (
35 '[ "pk_emails" ::: 'PrimaryKey '["id"]
34 '[ "pk_emails" ::: 'PrimaryKey '["id"]
36 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
35 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
37 ] :=>
36 ] :=>
38 '[ "id" ::: 'Def :=> 'NotNull 'PGint4
37 '[ "id" ::: 'Def :=> 'NotNull 'PGint4
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 & notNull) `As` #name :*
50+ (text & notNullable) `as` #name :*
49− (vararray int2 & notNull) `As` #vec :* Nil )
51+ (vararray int2 & notNullable) `as` #vec )
50− ( primaryKey (Column #id :* Nil) `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 & notNull) `As` #user_id :*
56+ hask @Int32 `as` #user_id :*
55− text `As` #email :* Nil )
57+ hask @(Maybe Text) `as` #email )
56− ( primaryKey (Column #id :* Nil) `As` #pk_emails :*
58+ ( primaryKey #id `as` #pk_emails :*
57− foreignKey (Column #user_id :* Nil) #users (Column #id :* Nil)
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+75−12
@@ -1,5 +1,5 @@
1name: squeal-postgresql
1name: squeal-postgresql
2−version: 0.2
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
@@ -22,63 +22,126 @@ 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
34 Squeal.PostgreSQL.Schema
62 Squeal.PostgreSQL.Schema
35 Squeal.PostgreSQL.Transaction
63 Squeal.PostgreSQL.Transaction
36 default-language: Haskell2010
64 default-language: Haskell2010
37− ghc-options: -Wall -fprint-explicit-kinds
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
68+ , base >= 4.11.1.0 && < 5.0
69+ , binary-parser >= 0.5.5
41 , bytestring >= 0.10.8.2
70 , bytestring >= 0.10.8.2
71+ , bytestring-strict-builder >= 0.4.5
42 , deepseq >= 1.4.3.0
72 , deepseq >= 1.4.3.0
73+ , free-categories >= 0.1.0.0
43− , generics-sop >= 0.3.2.0
74+ , generics-sop >= 0.3.2.0 && < 0.5.0.0
44− , lifted-base >= 0.2.3.12
45 , mmorph >= 1.1.1
75 , mmorph >= 1.1.1
46− , monad-control >= 1.0.2.3
47 , mtl >= 2.2.2
76 , mtl >= 2.2.2
48 , network-ip >= 0.3.0.2
77 , network-ip >= 0.3.0.2
49 , postgresql-binary >= 0.12.1
78 , postgresql-binary >= 0.12.1
50 , postgresql-libpq >= 0.9.4.1
79 , postgresql-libpq >= 0.9.4.1
80+ , records-sop >= 0.1.0.0
51 , resource-pool >= 0.2.3.2
81 , resource-pool >= 0.2.3.2
52 , scientific >= 0.3.5.3
82 , scientific >= 0.3.5.3
53 , text >= 1.2.3.0
83 , text >= 1.2.3.0
54 , time >= 1.8.0.2
84 , time >= 1.8.0.2
55 , transformers >= 0.5.2.0
85 , transformers >= 0.5.2.0
56− , transformers-base >= 0.4.4
86+ , unliftio >= 0.2.10
87+ , unliftio-pool >= 0.2.1.0
57 , uuid-types >= 1.0.3
88 , uuid-types >= 1.0.3
58 , vector >= 0.12.0.1
89 , vector >= 0.12.0.1
59
90
60−test-suite squeal-postgresql-doctest
91+test-suite doctest
61 default-language: Haskell2010
92 default-language: Haskell2010
62 type: exitcode-stdio-1.0
93 type: exitcode-stdio-1.0
63 hs-source-dirs: test
94 hs-source-dirs: test
64 ghc-options: -Wall
95 ghc-options: -Wall
65− main-is: DocTest.hs
96+ main-is: Doc.hs
66 build-depends:
97 build-depends:
67 base >= 4.10.0.0
98 base >= 4.10.0.0
68 , 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
69
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
70−executable squeal-postgresql-example
130+ , squeal-postgresql
131+ , text >= 1.2.2.2
132+ , vector >= 0.12.0.1
133+
134+executable example
71 default-language: Haskell2010
135 default-language: Haskell2010
72 hs-source-dirs: exe
136 hs-source-dirs: exe
73 ghc-options: -Wall
137 ghc-options: -Wall
74 main-is: Example.hs
138 main-is: Example.hs
75 build-depends:
139 build-depends:
76− base >= 4.10.0.0
140+ base >= 4.10.0.0 && < 5.0
77 , bytestring >= 0.10.8.2
141 , bytestring >= 0.10.8.2
78 , generics-sop >= 0.3.1.0
142 , generics-sop >= 0.3.1.0
79 , mtl >= 2.2.1
143 , mtl >= 2.2.1
80 , squeal-postgresql
144 , squeal-postgresql
81 , text >= 1.2.2.2
145 , text >= 1.2.2.2
82 , transformers >= 0.5.2.0
146 , transformers >= 0.5.2.0
83− , transformers-base >= 0.4.4
84 , vector >= 0.12.0.1
147 , vector >= 0.12.0.1
squeal-postgresql/src/Squeal/PostgreSQL.hs+233−222
@@ -1,222 +1,233 @@
1+{-|
1−-- | Module: Squeal.PostgreSQL
2+Module: Squeal.PostgreSQL
2−-- Description: Squeel export module
3+Description: Squeal export module
3−-- Copyright: (c) Eitan Chatav, 2017
4+Copyright: (c) Eitan Chatav, 2019
4−-- Maintainer: eitan@morphism.tech
5+Maintainer: eitan@morphism.tech
5−-- Stability: experimental
6+Stability: experimental
6−--
7+
7−-- Squeal is a deep embedding of [PostgreSQL](https://www.postgresql.org) in Haskell.
8+Squeal is a deep embedding of [PostgreSQL](https://www.postgresql.org) in Haskell.
8−-- Let's see an example!
9+Let's see an example!
9−--
10+
10−-- First, we need some language extensions because Squeal uses modern GHC
11+First, we need some language extensions because Squeal uses modern GHC
11−-- features.
12+features.
12−--
13+
13−-- >>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels
14+>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels -XFlexibleContexts
14−-- >>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators
15+>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators -XGADTs
15−--
16+
16−-- We'll need some imports.
17+We'll need some imports.
17−--
18+
18−-- >>> import Control.Monad (void)
19+>>> import Control.Monad.IO.Class (liftIO)
19−-- >>> import Control.Monad.Base (liftBase)
20−-- >>> import Data.Int (Int32)
20+>>> import Data.Int (Int32)
21−-- >>> import Data.Text (Text)
21+>>> import Data.Text (Text)
22−-- >>> import Squeal.PostgreSQL
22+>>> import Squeal.PostgreSQL
23−--
23+
24−-- We'll use generics to easily convert between Haskell and PostgreSQL values.
24+We'll use generics to easily convert between Haskell and PostgreSQL values.
25−--
25+
26−-- >>> import qualified Generics.SOP as SOP
26+>>> import qualified Generics.SOP as SOP
27−-- >>> import qualified GHC.Generics as GHC
27+>>> import qualified GHC.Generics as GHC
28−--
28+
29−-- The first step is to define the schema of our database. This is where
29+The first step is to define the schema of our database. This is where
30−-- we use @DataKinds@ and @TypeOperators@.
30+we use @DataKinds@ and @TypeOperators@.
31−--
31+
32−-- >>> :{
32+>>> :{
33−-- type Schema =
33+type UsersColumns =
34−-- '[ "users" :::
34+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
35+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext ]
35−-- '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
36+type UsersConstraints = '[ "pk_users" ::: 'PrimaryKey '["id"] ]
37+type EmailsColumns =
36−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4
38+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
37−-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext
39+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
38−-- ]
40+ , "email" ::: 'NoDef :=> 'Null 'PGtext ]
39−-- , "emails" :::
41+type EmailsConstraints =
40−-- '[ "pk_emails" ::: 'PrimaryKey '["id"]
42+ '[ "pk_emails" ::: 'PrimaryKey '["id"]
41−-- , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
43+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"] ]
42−-- ] :=>
44+type Schema =
43−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4
45+ '[ "users" ::: 'Table (UsersConstraints :=> UsersColumns)
44−-- , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
46+ , "emails" ::: 'Table (EmailsConstraints :=> EmailsColumns) ]
45−-- , "email" ::: 'NoDef :=> 'Null 'PGtext
47+type Schemas = Public Schema
46−-- ]
47−-- ]
48−-- :}
48+:}
49−--
49+
50−-- Notice the use of type operators. `:::` is used
50+Notice the use of type operators.
51+
51−-- to pair an alias `Symbol` with either a `TableType` or a `ColumnType`.
52+`:::` is used to pair an alias `GHC.TypeLits.Symbol` with a `SchemasType`, a `SchemumType`,
53+a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's @::@
54+operator.
55+
52−-- `:=>` is used to pair a `TableConstraint`s with a `ColumnsType`,
56+`:=>` is used to pair `TableConstraints` with a `ColumnsType`,
53−-- yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,
57+yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,
54−-- yielding a `ColumnType`.
58+yielding a `ColumnType`. It is intended to connote Haskell's @=>@ operator
55−--
59+
56−-- Next, we'll write `Definition`s to set up and tear down the schema. In
60+Next, we'll write `Definition`s to set up and tear down the schema. In
57−-- Squeal, a `Definition` is a `createTable`, `alterTable` or `dropTable`
61+Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`
58−-- command and has two type parameters, corresponding to the schema
62+has two type parameters, corresponding to the schema
59−-- before being run and the schema after. We can compose definitions using
63+before being run and the schema after. We can compose definitions using `>>>`.
60−-- `>>>`. Here and in the rest of our commands we make use of overloaded
64+Here and in the rest of our commands we make use of overloaded
61−-- labels to refer to named tables and columns in our schema.
65+labels to refer to named tables and columns in our schema.
62−--
66+
63−-- >>> :{
67+>>> :{
64−-- let
68+let
65−-- setup :: Definition '[] Schema
69+ setup :: Definition (Public '[]) Schemas
66−-- setup =
70+ setup =
67−-- createTable #users
71+ createTable #users
68−-- ( serial `As` #id :*
72+ ( serial `as` #id :*
69−-- (text & notNull) `As` #name :* Nil )
73+ (text & notNullable) `as` #name )
70−-- ( primaryKey (Column #id :* Nil) `As` #pk_users :* Nil ) >>>
74+ ( primaryKey #id `as` #pk_users ) >>>
71−-- createTable #emails
75+ createTable #emails
72−-- ( serial `As` #id :*
76+ ( serial `as` #id :*
73−-- (int & notNull) `As` #user_id :*
77+ (int & notNullable) `as` #user_id :*
74−-- text `As` #email :* Nil )
78+ (text & nullable) `as` #email )
75−-- ( primaryKey (Column #id :* Nil) `As` #pk_emails :*
79+ ( primaryKey #id `as` #pk_emails :*
76−-- foreignKey (Column #user_id :* Nil) #users (Column #id :* Nil)
80+ foreignKey #user_id #users #id
77−-- OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
81+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
78−-- :}
82+:}
79−--
83+
80−-- We can easily see the generated SQL is unsuprising looking.
84+We can easily see the generated SQL is unsurprising looking.
81−--
85+
82−-- >>> renderDefinition setup
86+>>> printSQL setup
87+CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));
83−-- "CREATE TABLE users (id serial, name text NOT NULL, CONSTRAINT pk_users PRIMARY KEY (id)); CREATE TABLE emails (id serial, user_id int NOT NULL, email text, CONSTRAINT pk_emails PRIMARY KEY (id), CONSTRAINT fk_user_id FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE ON UPDATE CASCADE);"
88+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);
84−--
89+
85−-- 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@.
86−-- In our `createTable` commands we included `TableConstraint`s to define
91+In our `createTable` commands we included `TableConstraint`s to define
87−-- primary and foreign keys, making them somewhat complex. Our tear down
92+primary and foreign keys, making them somewhat complex. Our @teardown@
88−-- `Definition` is simpler.
93+`Definition` is simpler.
89−--
94+
90−-- >>> :{
95+>>> :{
91−-- let
96+let
92−-- teardown :: Definition Schema '[]
97+ teardown :: Definition Schemas (Public '[])
93−-- teardown = dropTable #emails >>> dropTable #users
98+ teardown = dropTable #emails >>> dropTable #users
94−-- :}
99+:}
95−--
100+
96−-- >>> renderDefinition teardown
101+>>> printSQL teardown
97−-- "DROP TABLE emails; DROP TABLE users;"
102+DROP TABLE "emails";
98−--
103+DROP TABLE "users";
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+
99−-- 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.
100−-- A `Manipulation` is an `insertRow` (or other inserts), `update`
113+A `Manipulation_` like `insertInto`, `update` or `deleteFrom`
101−-- or `deleteFrom` command and
102−-- 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
103−-- it can take as input, and a list of columns it produces as output. When
115+and an output row. When
104−-- we insert into the users table, we will need a parameter for the @name@
116+we insert into the users table, we will need a parameter for the @name@
105−-- field but not for the @id@ field. Since it's optional, we can use a default
117+field but not for the @id@ field. Since it's serial, we can use a default
106−-- value. However, since the emails table refers to the users table, we will
118+value. However, since the emails table refers to the users table, we will
107−-- need to retrieve the user id that the insert generates and insert it into
119+need to retrieve the user id that the insert generates and insert it into
108−-- 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
109−-- of our inserts.
121+`with` statement.
110−--
122+
111−-- >>> :{
123+>>> :{
112−-- let
124+let
113−-- insertUser :: Manipulation Schema '[ 'NotNull 'PGtext ] '[ "fromOnly" ::: 'NotNull 'PGint4 ]
125+ insertUser :: Manipulation_ Schemas User ()
114−-- insertUser = insertRow #users
126+ insertUser = with (u `as` #u) e
127+ where
128+ u = insertInto #users
115−-- (Default `As` #id :* Set (param @1) `As` #name :* Nil)
129+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))
116−-- OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))
130+ OnConflictDoRaise (Returning_ (#id :* param @2 `as` #email))
117−-- :}
131+ e = insertInto_ #emails $ Select
118−--
132+ (Default `as` #id :* Set (#u ! #id) `as` #user_id :* Set (#u ! #email) `as` #email)
119−-- >>> :{
133+ (from (common #u))
120−-- let
121−-- insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]
122−-- insertEmail = insertRow #emails
123−-- ( Default `As` #id :*
124−-- Set (param @1) `As` #user_id :*
125−-- Set (param @2) `As` #email :* Nil )
126−-- OnConflictDoNothing (Returning Nil)
127−-- :}
134+:}
128−--
135+
129−-- >>> renderManipulation insertUser
136+>>> printSQL insertUser
130−-- "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"
131−-- >>> renderManipulation insertEmail
138+
132−-- "INSERT INTO emails (id, user_id, email) VALUES (DEFAULT, ($1 :: int4), ($2 :: text)) ON CONFLICT DO NOTHING;"
133−--
134−-- 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
135−-- interested in the ids here, just the usernames and email addresses. We
140+interested in the ids here, just the usernames and email addresses. We
136−-- 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
137−-- `Manipulation` with the same kind of type parameters.
142+`Manipulation_` with the same kind of type parameters.
138−--
143+
139−-- >>> :{
144+>>> :{
140−-- let
145+let
141−-- getUsers :: Query Schema '[]
146+ getUsers :: Query_ Schemas () User
142−-- '[ "userName" ::: 'NotNull 'PGtext
143−-- , "userEmail" ::: 'Null 'PGtext ]
144−-- getUsers = select
147+ getUsers = select_
145−-- (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* Nil)
148+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail)
146−-- ( from (table (#users `As` #u)
149+ ( from (table (#users `as` #u)
147−-- & innerJoin (table (#emails `As` #e))
150+ & innerJoin (table (#emails `as` #e))
148−-- (#u ! #id .== #e ! #user_id)) )
151+ (#u ! #id .== #e ! #user_id)) )
149−-- :}
152+:}
150−--
153+
151−-- >>> renderQuery getUsers
154+>>> printSQL getUsers
152−-- "SELECT u.name AS userName, e.email AS userEmail FROM users AS u INNER JOIN emails AS e ON (u.id = e.user_id)"
155+SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")
153−--
156+
154−-- Now that we've defined the SQL side of things, we'll need a Haskell type
155−-- for users. We give the type `Generics.SOP.Generic` and
156−-- `Generics.SOP.HasDatatypeInfo` instances so that we can decode the rows
157−-- we receive when we run @getUsers@. Notice that the record fields of the
158−-- @User@ type match the column names of @getUsers@.
159−--
160−-- >>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, GHC.Generic)
161−-- >>> instance SOP.Generic User
162−-- >>> instance SOP.HasDatatypeInfo User
163−--
164−-- Let's also create some users to add to the database.
157+Let's create some users to add to the database.
165−--
158+
166−-- >>> :{
159+>>> :{
167−-- let
160+let
168−-- users :: [User]
161+ users :: [User]
169−-- users =
162+ users =
170−-- [ User "Alice" (Just "alice@gmail.com")
163+ [ User "Alice" (Just "alice@gmail.com")
171−-- , User "Bob" Nothing
164+ , User "Bob" Nothing
172−-- , User "Carole" (Just "carole@hotmail.com")
165+ , User "Carole" (Just "carole@hotmail.com")
173−-- ]
166+ ]
174−-- :}
167+:}
175−--
168+
176−-- Now we can put together all the pieces into a program. The program
169+Now we can put together all the pieces into a program. The program
177−-- connects to the database, sets up the schema, inserts the user data
170+connects to the database, sets up the schema, inserts the user data
178−-- (using prepared statements as an optimization), queries the user
171+(using prepared statements as an optimization), queries the user
179−-- data and prints it out and finally closes the connection. We can thread
172+data and prints it out and finally closes the connection. We can thread
180−-- the changing schema information through by using the indexed `PQ` monad
173+the changing schema information through by using the indexed `PQ` monad
181−-- transformer and when the schema doesn't change we can use `Monad` and
174+transformer and when the schema doesn't change we can use `Monad` and
182−-- `MonadPQ` functionality.
175+`MonadPQ` functionality.
183−--
176+
184−-- >>> :{
177+>>> :{
185−-- let
178+let
186−-- session :: PQ Schema Schema IO ()
179+ session :: PQ Schemas Schemas IO ()
187−-- session = do
180+ session = do
188−-- idResults <- traversePrepared insertUser (Only . userName <$> users)
189−-- ids <- traverse (fmap fromOnly . getRow 0) idResults
190−-- traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))
181+ _ <- traversePrepared_ insertUser users
191−-- usersResult <- runQuery getUsers
182+ usersResult <- runQuery getUsers
192−-- usersRows <- getRows usersResult
183+ usersRows <- getRows usersResult
193−-- liftBase $ print (usersRows :: [User])
184+ liftIO $ print (usersRows :: [User])
194−-- :}
185+in
195−--
196−-- >>> :{
197−-- void . withConnection "host=localhost port=5432 dbname=exampledb" $
186+ withConnection "host=localhost port=5432 dbname=exampledb" $
198−-- define setup
187+ define setup
199−-- & pqThen session
188+ & pqThen session
200−-- & pqThen (define teardown)
189+ & pqThen (define teardown)
201−-- :}
190+:}
202−-- [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"}]
203−
192+-}
204−module Squeal.PostgreSQL
193+module Squeal.PostgreSQL (module X, RenderSQL(..), printSQL) where
194+
205− ( module Squeal.PostgreSQL.Binary
195+import Squeal.PostgreSQL.Alias as X
196+import Squeal.PostgreSQL.Binary as X
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
206− , module Squeal.PostgreSQL.Definition
203+import Squeal.PostgreSQL.Definition.Type as X
204+import Squeal.PostgreSQL.Definition.View as X
207− , module Squeal.PostgreSQL.Expression
205+import Squeal.PostgreSQL.Expression as X
206+import Squeal.PostgreSQL.Expression.Aggregate as X
208− , module Squeal.PostgreSQL.Manipulation
207+import Squeal.PostgreSQL.Expression.Collection as X
208+import Squeal.PostgreSQL.Expression.Comparison as X
209− , module Squeal.PostgreSQL.PQ
209+import Squeal.PostgreSQL.Expression.Json as X
210+import Squeal.PostgreSQL.Expression.Literal as X
210− , module Squeal.PostgreSQL.Query
211+import Squeal.PostgreSQL.Expression.Logic as X
212+import Squeal.PostgreSQL.Expression.Math as X
211− , module Squeal.PostgreSQL.Schema
213+import Squeal.PostgreSQL.Expression.Null as X
214+import Squeal.PostgreSQL.Expression.Parameter as X
212− , module Squeal.PostgreSQL.Transaction
215+import Squeal.PostgreSQL.Expression.Range as X
213− ) where
216+import Squeal.PostgreSQL.Expression.Set as X
214−
217+import Squeal.PostgreSQL.Expression.Sort as X
215−import Squeal.PostgreSQL.Binary
218+import Squeal.PostgreSQL.Expression.Subquery as X
216−import Squeal.PostgreSQL.Definition
219+import Squeal.PostgreSQL.Expression.Text as X
217−import Squeal.PostgreSQL.Expression
220+import Squeal.PostgreSQL.Expression.TextSearch as X
218−import Squeal.PostgreSQL.Manipulation
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
225+import Squeal.PostgreSQL.Manipulation as X
226+import Squeal.PostgreSQL.Migration as X
219−import Squeal.PostgreSQL.PQ
227+import Squeal.PostgreSQL.PG as X
228+import Squeal.PostgreSQL.Pool as X
229+import Squeal.PostgreSQL.PQ as X
220−import Squeal.PostgreSQL.Query
230+import Squeal.PostgreSQL.Query as X
221−import Squeal.PostgreSQL.Schema
231+import Squeal.PostgreSQL.Render (RenderSQL(..), printSQL)
232+import Squeal.PostgreSQL.Schema as X
222−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+690−119
@@ -5,22 +5,192 @@ Copyright: (c) Eitan Chatav, 2017
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
7
7
8−Binary encoding and decoding between Haskell and PostgreSQL types.
8+This module provides binary encoding and decoding between Haskell and PostgreSQL types.
9+
10+Instances are governed by the `SOP.Generic` and `SOP.HasDatatypeInfo` typeclasses, so you absolutely
11+do not need to define your own instances to decode retrieved rows into Haskell values or
12+to encode Haskell values into statement parameters.
13+
14+Let's see some examples. We'll need some imports
15+
16+>>> import Data.Int (Int16)
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.
24+
25+>>> data Row = Row { col1 :: Int16, col2 :: Text, col3 :: Maybe Bool } deriving (Eq, GHC.Generic)
26+>>> instance Generic 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+:}
36+
37+So long as we can encode the parameters and then decode the result of the query,
38+the input and output should be equal.
39+
40+>>> let input = Row 2 "hi" (Just True)
41+>>> :{
42+withConnection "host=localhost port=5432 dbname=exampledb" $ do
43+ result <- runQueryParams roundTrip input
44+ Just output <- firstRow result
45+ liftIO . print $ input == output
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.
68+
69+>>> :{
70+let
71+ roundTrip :: Query_ (Public '[]) Row Row
72+ roundTrip = values_ $
73+ parameter @1 (int2 & vararray) `as` #col1 :*
74+ parameter @2 (int2 & fixarray @'[2]) `as` #col2 :*
75+ parameter @3 (int2 & fixarray @'[3,2]) `as` #col3
76+:}
77+
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+:}
86+True
87+
88+Enumerated (enum) types are data types that comprise a static, ordered set of values.
89+They are equivalent to Haskell algebraic data types whose constructors are nullary.
90+An example of an enum type might be the days of the week,
91+or a set of status values for a piece of data.
92+
93+>>> data Schwarma = Beef | Lamb | Chicken deriving (Eq, Show, GHC.Generic)
94+>>> instance Generic Schwarma
95+>>> instance HasDatatypeInfo Schwarma
96+
97+A composite type represents the structure of a row or record;
98+it is essentially just a list of field names and their data types.
99+
100+>>> data Person = Person {name :: Text, age :: Int32} deriving (Eq, Show, GHC.Generic)
101+>>> instance Generic Person
102+>>> instance HasDatatypeInfo Person
103+>>> instance Aeson.FromJSON Person
104+>>> instance Aeson.ToJSON Person
105+
106+We can create the equivalent Postgres types directly from their Haskell types.
107+
108+>>> :{
109+type Schema =
110+ '[ "schwarma" ::: 'Typedef (PG (Enumerated Schwarma))
111+ , "person" ::: 'Typedef (PG (Composite Person))
112+ ]
113+:}
114+
115+>>> :{
116+let
117+ setup :: Definition (Public '[]) (Public Schema)
118+ setup =
119+ createTypeEnumFrom @Schwarma #schwarma >>>
120+ createTypeCompositeFrom @Person #person
121+:}
122+
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.
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
137+>>> :{
138+let
139+ input = Row
140+ (Enumerated Chicken)
141+ (Composite (Person "Faisal" 24))
142+ (Json (Person "Ahmad" 48))
143+:}
144+
145+Once again, define a round trip query.
146+
147+>>> :{
148+let
149+ roundTrip :: Query_ (Public Schema) Row Row
150+ roundTrip = values_ $
151+ parameter @1 (typedef #schwarma) `as` #schwarma :*
152+ parameter @2 (typedef #person) `as` #person1 :*
153+ parameter @3 json `as` #person2
154+:}
155+
156+Finally, we can drop our type definitions.
157+
158+>>> :{
159+let
160+ teardown :: Definition (Public Schema) (Public '[])
161+ teardown = dropType #schwarma >>> dropType #person
162+:}
163+
164+Now let's run it.
165+
166+>>> :{
167+let
168+ session = do
169+ result <- runQueryParams roundTrip input
170+ Just output <- firstRow result
171+ liftIO . print $ input == output
172+in
173+ withConnection "host=localhost port=5432 dbname=exampledb" $
174+ define setup
175+ & pqThen session
176+ & pqThen (define teardown)
177+:}
178+True
9-}
179-}
10
180
11{-# LANGUAGE
181{-# LANGUAGE
12− ConstraintKinds
182+ AllowAmbiguousTypes
13− , DataKinds
14− , DefaultSignatures
15 , DeriveFoldable
183 , DeriveFoldable
16 , DeriveFunctor
184 , DeriveFunctor
17 , DeriveGeneric
185 , DeriveGeneric
18 , DeriveTraversable
186 , DeriveTraversable
187+ , DefaultSignatures
19 , FlexibleContexts
188 , FlexibleContexts
20 , FlexibleInstances
189 , FlexibleInstances
190+ , FunctionalDependencies
21 , GADTs
191 , GADTs
22 , LambdaCase
192 , LambdaCase
23− , KindSignatures
193+ , OverloadedStrings
24 , MultiParamTypeClasses
194 , MultiParamTypeClasses
25 , ScopedTypeVariables
195 , ScopedTypeVariables
26 , TypeApplications
196 , TypeApplications
@@ -28,22 +198,33 @@ Binary encoding and decoding between Haskell and PostgreSQL types.
28 , TypeInType
198 , TypeInType
29 , TypeOperators
199 , TypeOperators
30 , UndecidableInstances
200 , UndecidableInstances
201+ , UndecidableSuperClasses
31#-}
202#-}
32
203
33module Squeal.PostgreSQL.Binary
204module Squeal.PostgreSQL.Binary
34 ( -- * Encoding
205 ( -- * Encoding
35 ToParam (..)
206 ToParam (..)
36− , ToColumnParam (..)
37 , ToParams (..)
207 , ToParams (..)
208+ , ToNullityParam (..)
209+ , ToField (..)
210+ , ToFixArray (..)
38 -- * Decoding
211 -- * Decoding
39 , FromValue (..)
212 , FromValue (..)
40− , FromColumnValue (..)
41 , FromRow (..)
213 , FromRow (..)
214+ , FromField (..)
215+ , FromFixArray (..)
42 -- * Only
216 -- * Only
43 , Only (..)
217 , Only (..)
218+ -- * Oid
219+ , OidOf (..)
220+ , OidOfParam (..)
221+ , OidOfField (..)
44 ) where
222 ) where
45
223
46−import Data.Aeson hiding (Null)
224+import BinaryParser
225+import ByteString.StrictBuilder (builderLength, int32BE, int64BE, word32BE)
226+import Control.Arrow (left)
227+import Control.Monad
47import Data.Int
228import Data.Int
48import Data.Kind
229import Data.Kind
49import Data.Scientific
230import Data.Scientific
@@ -51,19 +232,28 @@ import Data.Time
51import Data.UUID.Types
232import Data.UUID.Types
52import Data.Vector (Vector)
233import Data.Vector (Vector)
53import Data.Word
234import Data.Word
235+import Foreign.C.Types (CUInt(CUInt))
54import Generics.SOP
236import Generics.SOP
237+import Generics.SOP.Record
55import GHC.TypeLits
238import GHC.TypeLits
56import Network.IP.Addr
239import Network.IP.Addr
57
240
58−import qualified Data.ByteString.Lazy as Lazy
241+import qualified Data.Aeson as Aeson
242+import qualified Data.ByteString.Lazy as Lazy (ByteString)
243+import qualified Data.ByteString.Lazy as Lazy.ByteString
59−import qualified Data.ByteString as Strict hiding (unpack)
244+import qualified Data.ByteString as Strict (ByteString)
60−import qualified Data.Text.Lazy as Lazy
245+import qualified Data.Text.Lazy as Lazy (Text)
61−import qualified Data.Text as Strict
246+import qualified Data.Text as Strict (Text)
247+import qualified Data.Text as Strict.Text
62import qualified Data.Vector as Vector
248import qualified Data.Vector as Vector
249+import qualified Database.PostgreSQL.LibPQ as LibPQ
63import qualified GHC.Generics as GHC
250import qualified GHC.Generics as GHC
64import qualified PostgreSQL.Binary.Decoding as Decoding
251import qualified PostgreSQL.Binary.Decoding as Decoding
65import qualified PostgreSQL.Binary.Encoding as Encoding
252import qualified PostgreSQL.Binary.Encoding as Encoding
66
253
254+import Squeal.PostgreSQL.Alias
255+import Squeal.PostgreSQL.List
256+import Squeal.PostgreSQL.PG
67import Squeal.PostgreSQL.Schema
257import Squeal.PostgreSQL.Schema
68
258
69-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into
259-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into
@@ -87,19 +277,20 @@ class ToParam (x :: Type) (pg :: PGType) where
87 toParam :: x -> K Encoding.Encoding pg
277 toParam :: x -> K Encoding.Encoding pg
88instance ToParam Bool 'PGbool where toParam = K . Encoding.bool
278instance ToParam Bool 'PGbool where toParam = K . Encoding.bool
89instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16
279instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16
90−instance ToParam Word16 'PGint2 where toParam = K . Encoding.int2_word16
91instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32
280instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32
92−instance ToParam Word32 'PGint4 where toParam = K . Encoding.int4_word32
93instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64
281instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64
94−instance ToParam Word64 'PGint8 where toParam = K . Encoding.int8_word64
282+instance ToParam Oid 'PGoid where toParam = K . Encoding.int4_word32 . getOid
95instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4
283instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4
96instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8
284instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8
97instance 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
98instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid
287instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid
99instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet
288instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet
100instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8
289instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8
101instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict
290instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict
102instance 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
103instance ToParam Strict.ByteString 'PGbytea where
294instance ToParam Strict.ByteString 'PGbytea where
104 toParam = K . Encoding.bytea_strict
295 toParam = K . Encoding.bytea_strict
105instance ToParam Lazy.ByteString 'PGbytea where
296instance ToParam Lazy.ByteString 'PGbytea where
@@ -113,34 +304,256 @@ instance ToParam LocalTime 'PGtimestamp where
113instance ToParam UTCTime 'PGtimestamptz where
304instance ToParam UTCTime 'PGtimestamptz where
114 toParam = K . Encoding.timestamptz_int
305 toParam = K . Encoding.timestamptz_int
115instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int
306instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int
116−instance ToParam Value 'PGjson where toParam = K . Encoding.json_ast
307+instance ToParam Aeson.Value 'PGjson where toParam = K . Encoding.json_ast
117−instance ToParam Value 'PGjsonb where toParam = K . Encoding.jsonb_ast
308+instance ToParam Aeson.Value 'PGjsonb where toParam = K . Encoding.jsonb_ast
118−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)
119− => ToParam (Vector (Maybe x)) ('PGvararray pg) where
327+ => ToParam (VarArray (Vector (Maybe x))) ('PGvararray ('Null pg)) where
328+ toParam = K
120− toParam = K . Encoding.nullableArray_vector
329+ . Encoding.nullableArray_vector
121− (oid @pg) (unK . toParam @x @pg)
330+ (getOid (oidOf @pg)) (unK . toParam @x @pg)
122−
331+ . getVarArray
123−-- | A `ToColumnParam` constraint lifts the `ToParam` encoding
332+instance (ToFixArray x dims ty, ty ~ nullity pg, OidOf pg)
124−-- of a `Type` to a `ColumnType`, encoding `Maybe`s to `Null`s. You should
333+ => ToParam (FixArray x) ('PGfixarray dims ty) where
125−-- not define instances of `ToColumnParam`, just use the provided instances.
334+ toParam = K . Encoding.array (getOid (oidOf @pg))
126−class ToColumnParam (x :: Type) (ty :: NullityType) where
335+ . unK . unK . toFixArray @x @dims @ty . getFixArray
127− -- | >>> toColumnParam @Int16 @('NotNull 'PGint2) 0
336+instance
128− -- K (Just "\NUL\NUL")
337+ ( IsEnumType x
129− --
338+ , HasDatatypeInfo x
130− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) (Just 0)
339+ , LabelsPG x ~ labels
131− -- K (Just "\NUL\NUL")
340+ ) => ToParam (Enumerated x) ('PGenum labels) where
132− --
341+ toParam =
133− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) Nothing
342+ let
134− -- K Nothing
343+ gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String
135− toColumnParam :: x -> K (Maybe Strict.ByteString) ty
344+ gshowConstructor Nil _ = ""
345+ gshowConstructor (constructor :* _) (SOP (Z _)) =
346+ constructorName constructor
347+ gshowConstructor (_ :* constructors) (SOP (S xs)) =
348+ gshowConstructor constructors (SOP xs)
349+ in
350+ K . Encoding.text_strict
351+ . Strict.Text.pack
352+ . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))
353+ . from
354+ . getEnumerated
355+instance
356+ ( SListI fields
357+ , IsRecord x xs
358+ , AllZip ToField xs fields
359+ , All OidOfField fields
360+ ) => ToParam (Composite x) ('PGcomposite fields) where
361+ toParam =
362+ let
363+
364+ encoders = htrans (Proxy @ToField) toField
365+
366+ composite
367+ :: All OidOfField row
368+ => NP (K (Maybe Encoding.Encoding)) row
369+ -> K Encoding.Encoding ('PGcomposite row)
370+ composite fields = K $
371+ -- <number of fields: 4 bytes>
372+ -- [for each field]
373+ -- <OID of field's type: sizeof(Oid) bytes>
374+ -- [if value is NULL]
375+ -- <-1: 4 bytes>
376+ -- [else]
377+ -- <length of value: 4 bytes>
378+ -- <value: <length> bytes>
379+ -- [end if]
380+ -- [end for]
381+ int32BE (fromIntegral (lengthSList (Proxy @xs))) <>
382+ let
383+ each
384+ :: OidOfField field
385+ => K (Maybe Encoding.Encoding) field
386+ -> Encoding.Encoding
387+ each (K field :: K (Maybe Encoding.Encoding) field) =
388+ word32BE (getOid (oidOfField @field))
389+ <> case field of
390+ Nothing -> int64BE (-1)
391+ Just value ->
392+ int32BE (fromIntegral (builderLength value))
393+ <> value
394+ in
395+ hcfoldMap (Proxy @OidOfField) each fields
396+
397+ in
398+ composite . encoders . toRecord . getComposite
399+
400+-- | The object identifier of a `PGType`.
401+--
402+-- >>> :set -XTypeApplications
403+-- >>> oidOf @'PGbool
404+-- Oid 16
405+class OidOf (ty :: PGType) where oidOf :: LibPQ.Oid
406+instance OidOf 'PGbool where oidOf = LibPQ.Oid 16
407+instance OidOf ('PGfixarray ns (null 'PGbool)) where oidOf = LibPQ.Oid 1000
408+instance OidOf ('PGvararray (null 'PGbool)) where oidOf = LibPQ.Oid 1000
409+instance OidOf 'PGint2 where oidOf = LibPQ.Oid 21
410+instance OidOf ('PGfixarray ns (null 'PGint2)) where oidOf = LibPQ.Oid 1005
411+instance OidOf ('PGvararray (null 'PGint2)) where oidOf = LibPQ.Oid 1005
412+instance OidOf 'PGint4 where oidOf = LibPQ.Oid 23
413+instance OidOf ('PGfixarray ns (null 'PGint4)) where oidOf = LibPQ.Oid 1007
414+instance OidOf ('PGvararray (null 'PGint4)) where oidOf = LibPQ.Oid 1007
415+instance OidOf 'PGint8 where oidOf = LibPQ.Oid 20
416+instance OidOf ('PGfixarray ns (null 'PGint8)) where oidOf = LibPQ.Oid 1016
417+instance OidOf ('PGvararray (null 'PGint8)) where oidOf = LibPQ.Oid 1016
418+instance OidOf 'PGnumeric where oidOf = LibPQ.Oid 1700
419+instance OidOf ('PGfixarray ns (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231
420+instance OidOf ('PGvararray (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231
421+instance OidOf 'PGfloat4 where oidOf = LibPQ.Oid 700
422+instance OidOf ('PGfixarray ns (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021
423+instance OidOf ('PGvararray (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021
424+instance OidOf 'PGfloat8 where oidOf = LibPQ.Oid 701
425+instance OidOf ('PGfixarray ns (null 'PGfloat8)) where oidOf = LibPQ.Oid 1022
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
136−instance ToParam x pg => ToColumnParam x ('NotNull pg) where
522+instance ToParam x pg => ToNullityParam x ('NotNull pg) where
137− toColumnParam = K . Just . Encoding.encodingBytes . unK . toParam @x @pg
523+ toNullityParam = K . Just . unK . toParam @x @pg
138−instance ToParam x pg => ToColumnParam (Maybe x) ('Null pg) where
524+instance ToParam x pg => ToNullityParam (Maybe x) ('Null pg) where
139− toColumnParam = K . fmap (Encoding.encodingBytes . unK . toParam @x @pg)
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
140
553
141-- | A `ToParams` constraint generically sequences the encodings of `Type`s
554-- | A `ToParams` constraint generically sequences the encodings of `Type`s
142-- 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
143−-- not define instances of `ToParams`. Instead define `Generic` instances
556+-- not define instances of `ToParams`. Instead define `SOP.Generic` instances
144-- which in turn provide `ToParams` instances.
557-- which in turn provide `ToParams` instances.
145class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where
558class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where
146 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]
559 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]
@@ -152,115 +565,257 @@ class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where
152 -- >>> instance Generic Tuple
565 -- >>> instance Generic Tuple
153 -- >>> toParams @Tuple @Params (Tuple False (Just 0))
566 -- >>> toParams @Tuple @Params (Tuple False (Just 0))
154 -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil
567 -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil
155− toParams :: x -> NP (K (Maybe Strict.ByteString)) tys
568+ toParams :: x -> NP (K (Maybe Encoding.Encoding)) tys
156−instance (SListI tys, IsProductType x xs, AllZip ToColumnParam xs tys)
569+instance (SListI tys, IsProductType x xs, AllZip ToNullityParam xs tys)
157 => ToParams x tys where
570 => ToParams x tys where
158 toParams
571 toParams
159− = htrans (Proxy @ToColumnParam) (toColumnParam . unI)
572+ = htrans (Proxy @ToNullityParam) (toNullityParam . unI)
160 . unZ . unSOP . from
573 . unZ . unSOP . from
161
574
162-- | A `FromValue` constraint gives a parser from the binary format of
575-- | A `FromValue` constraint gives a parser from the binary format of
163-- a PostgreSQL `PGType` into a Haskell `Type`.
576-- a PostgreSQL `PGType` into a Haskell `Type`.
164class FromValue (pg :: PGType) (y :: Type) where
577class FromValue (pg :: PGType) (y :: Type) where
165 -- | >>> newtype Id = Id { getId :: Int16 } deriving Show
578 -- | >>> newtype Id = Id { getId :: Int16 } deriving Show
166− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue
579+ -- >>> instance FromValue 'PGint2 Id where fromValue = Id <$> fromValue @'PGint2
167− fromValue :: proxy pg -> Decoding.Value y
580+ fromValue :: Decoding.Value y
168−instance FromValue 'PGbool Bool where fromValue _ = Decoding.bool
581+instance FromValue 'PGbool Bool where fromValue = Decoding.bool
169−instance FromValue 'PGint2 Int16 where fromValue _ = Decoding.int
582+instance FromValue 'PGint2 Int16 where fromValue = Decoding.int
170−instance FromValue 'PGint4 Int32 where fromValue _ = Decoding.int
583+instance FromValue 'PGint4 Int32 where fromValue = Decoding.int
171−instance FromValue 'PGint8 Int64 where fromValue _ = Decoding.int
584+instance FromValue 'PGint8 Int64 where fromValue = Decoding.int
585+instance FromValue 'PGoid Word32 where fromValue = Decoding.int
172−instance FromValue 'PGfloat4 Float where fromValue _ = Decoding.float4
586+instance FromValue 'PGfloat4 Float where fromValue = Decoding.float4
173−instance FromValue 'PGfloat8 Double where fromValue _ = Decoding.float8
587+instance FromValue 'PGfloat8 Double where fromValue = Decoding.float8
174−instance FromValue 'PGnumeric Scientific where fromValue _ = Decoding.numeric
588+instance FromValue 'PGnumeric Scientific where fromValue = Decoding.numeric
589+instance FromValue 'PGmoney Money where fromValue = Money <$> Decoding.int
175−instance FromValue 'PGuuid UUID where fromValue _ = Decoding.uuid
590+instance FromValue 'PGuuid UUID where fromValue = Decoding.uuid
176−instance FromValue 'PGinet (NetAddr IP) where fromValue _ = Decoding.inet
591+instance FromValue 'PGinet (NetAddr IP) where fromValue = Decoding.inet
177−instance FromValue ('PGchar 1) Char where fromValue _ = Decoding.char
592+instance FromValue ('PGchar 1) Char where fromValue = Decoding.char
178−instance FromValue 'PGtext Strict.Text where fromValue _ = Decoding.text_strict
593+instance FromValue 'PGtext Strict.Text where fromValue = Decoding.text_strict
179−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 <$> Decoding.text_strict
180instance FromValue 'PGbytea Strict.ByteString where
597instance FromValue 'PGbytea Strict.ByteString where
181− fromValue _ = Decoding.bytea_strict
598+ fromValue = Decoding.bytea_strict
182instance FromValue 'PGbytea Lazy.ByteString where
599instance FromValue 'PGbytea Lazy.ByteString where
183− fromValue _ = Decoding.bytea_lazy
600+ fromValue = Decoding.bytea_lazy
184−instance FromValue 'PGdate Day where fromValue _ = Decoding.date
601+instance FromValue 'PGdate Day where fromValue = Decoding.date
185−instance FromValue 'PGtime TimeOfDay where fromValue _ = Decoding.time_int
602+instance FromValue 'PGtime TimeOfDay where fromValue = Decoding.time_int
186instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where
603instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where
187− fromValue _ = Decoding.timetz_int
604+ fromValue = Decoding.timetz_int
188instance FromValue 'PGtimestamp LocalTime where
605instance FromValue 'PGtimestamp LocalTime where
189− fromValue _ = Decoding.timestamp_int
606+ fromValue = Decoding.timestamp_int
190instance FromValue 'PGtimestamptz UTCTime where
607instance FromValue 'PGtimestamptz UTCTime where
191− fromValue _ = Decoding.timestamptz_int
608+ fromValue = Decoding.timestamptz_int
192instance FromValue 'PGinterval DiffTime where
609instance FromValue 'PGinterval DiffTime where
193− fromValue _ = Decoding.interval_int
610+ fromValue = Decoding.interval_int
194−instance FromValue 'PGjson Value where fromValue _ = Decoding.json_ast
611+instance FromValue 'PGjson Aeson.Value where fromValue = Decoding.json_ast
195−instance FromValue 'PGjsonb Value where fromValue _ = Decoding.jsonb_ast
612+instance FromValue 'PGjsonb Aeson.Value where fromValue = Decoding.jsonb_ast
613+instance Aeson.FromJSON x => FromValue 'PGjson (Json x) where
614+ fromValue = Json <$>
615+ Decoding.json_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)
616+instance Aeson.FromJSON x => FromValue 'PGjsonb (Jsonb x) where
617+ fromValue = Jsonb <$>
618+ Decoding.jsonb_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)
619+instance FromValue pg y
196−instance FromValue pg y => FromValue ('PGvararray pg) (Vector (Maybe y)) where
620+ => FromValue ('PGvararray ('NotNull pg)) (VarArray (Vector y)) where
197− fromValue _ = Decoding.array
621+ fromValue =
622+ let
623+ rep n x = VarArray <$> Vector.replicateM n x
624+ in
198− (Decoding.dimensionArray Vector.replicateM
625+ Decoding.array $ Decoding.dimensionArray rep
199− (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))
200−instance FromValue pg y => FromValue ('PGfixarray n pg) (Vector (Maybe y)) where
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
652+ => FromValue ('PGfixarray dims ty) (FixArray y) where
653+ fromValue = FixArray <$> Decoding.array (fromFixArray @dims @ty @y)
654+instance
655+ ( IsEnumType y
656+ , HasDatatypeInfo y
657+ , LabelsPG y ~ labels
658+ ) => FromValue ('PGenum labels) (Enumerated y) where
201− fromValue _ = Decoding.array
659+ fromValue =
202− (Decoding.dimensionArray Vector.replicateM
660+ let
203− (Decoding.nullableValueArray (fromValue (Proxy @pg))))
661+ greadConstructor
204−
662+ :: All ((~) '[]) xss
663+ => NP ConstructorInfo xss
664+ -> String
665+ -> Maybe (SOP I xss)
666+ greadConstructor Nil _ = Nothing
667+ greadConstructor (constructor :* constructors) name =
668+ if name == constructorName constructor
669+ then Just (SOP (Z Nil))
670+ else SOP . S . unSOP <$> greadConstructor constructors name
671+ in
672+ fmap Enumerated
673+ . Decoding.enum
674+ $ fmap to
675+ . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))
676+ . Strict.Text.unpack
677+instance
678+ ( FromRow fields y
679+ ) => FromValue ('PGcomposite fields) (Composite y) where
680+ fromValue =
681+ let
682+ -- <number of fields: 4 bytes>
683+ -- [for each field]
684+ -- <OID of field's type: sizeof(Oid) bytes>
685+ -- [if value is NULL]
686+ -- <-1: 4 bytes>
687+ -- [else]
688+ -- <length of value: 4 bytes>
689+ -- <value: <length> bytes>
690+ -- [end if]
691+ -- [end for]
692+ composite = Decoding.valueParser $ do
693+ unitOfSize 4
694+ hsequence' $ hpure $ Comp $ do
695+ unitOfSize 4
696+ len <- sized 4 Decoding.int
697+ if len == -1
698+ then return (K Nothing)
699+ else K . Just <$> bytesOfSize len
700+ in
701+ fmap Composite (Decoding.fn (fromRow @fields <=< composite))
702+
205−-- | A `FromColumnValue` constraint lifts the `FromValue` parser
703+-- | A `FromField` constraint lifts the `FromValue` parser
206−-- to a decoding of a @(Symbol, ColumnType)@ to a `Type`,
704+-- to a decoding of a @(Symbol, NullityType)@ to a `Type`,
207-- decoding `Null`s to `Maybe`s. You should not define instances for
705-- decoding `Null`s to `Maybe`s. You should not define instances for
208−-- `FromColumnValue`, just use the provided instances.
706+-- `FromField`, just use the provided instances.
209−class FromColumnValue (colty :: (Symbol,NullityType)) (y :: Type) where
707+class FromField (pg :: (Symbol, NullityType)) (y :: (Symbol, Type)) where
210− -- | >>> :set -XTypeOperators -XOverloadedStrings
708+ fromField
211− -- >>> newtype Id = Id { getId :: Int16 } deriving Show
212− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue
213− -- >>> fromColumnValue @("col" ::: 'NotNull 'PGint2) @Id (K (Just "\NUL\SOH"))
214− -- Id {getId = 1}
215− --
216− -- >>> fromColumnValue @("col" ::: 'Null 'PGint2) @(Maybe Id) (K (Just "\NUL\SOH"))
217− -- Just (Id {getId = 1})
218− fromColumnValue :: K (Maybe Strict.ByteString) colty -> y
709+ :: K (Maybe Strict.ByteString) pg
710+ -> (Either Strict.Text :.: P) y
219instance FromValue pg y
711instance FromValue pg y
220− => FromColumnValue (column ::: ('NotNull pg)) y where
712+ => FromField (column ::: ('NotNull pg)) (column ::: y) where
221− fromColumnValue = \case
713+ fromField = Comp . \case
222− K Nothing -> error "fromColumnValue: saw NULL when expecting NOT NULL"
714+ K Nothing -> Left "fromField: saw NULL when expecting NOT NULL"
223− K (Just bytes) ->
715+ K (Just bytestring) -> P <$>
224− let
225− errOrValue =
226− Decoding.valueParser (fromValue @pg @y Proxy) bytes
716+ Decoding.valueParser (fromValue @pg) bytestring
227− err str = error $ "fromColumnValue: " ++ Strict.unpack str
228− in
229− either err id errOrValue
230instance FromValue pg y
717instance FromValue pg y
231− => FromColumnValue (column ::: ('Null pg)) (Maybe y) where
718+ => FromField (column ::: 'Null pg) (column ::: Maybe y) where
232− fromColumnValue (K nullOrBytes)
719+ fromField = Comp . \case
233− = either err id
720+ K Nothing -> Right $ P Nothing
234− . Decoding.valueParser (fromValue @pg @y Proxy)
721+ K (Just bytestring) -> P . Just <$>
235− <$> nullOrBytes
722+ Decoding.valueParser (fromValue @pg) bytestring
236− where
723+
237− 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)
238
745
239-- | A `FromRow` constraint generically sequences the parsings of the columns
746-- | A `FromRow` constraint generically sequences the parsings of the columns
240−-- 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
241-- the same field names. You should not define instances of `FromRow`.
748-- the same field names. You should not define instances of `FromRow`.
242−-- Instead define `Generic` and `HasDatatypeInfo` instances which in turn
749+-- Instead define `SOP.Generic` and `SOP.HasDatatypeInfo` instances which in turn
243-- provide `FromRow` instances.
750-- provide `FromRow` instances.
244−class SListI results => FromRow (results :: RelationType) y where
751+class SListI result => FromRow (result :: RowType) y where
245 -- | >>> :set -XOverloadedStrings
752 -- | >>> :set -XOverloadedStrings
246 -- >>> import Data.Text
753 -- >>> import Data.Text
247 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show
754 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show
248− -- >>> instance FromValue 'PGint2 UserId where fromValue = fmap UserId . fromValue
755+ -- >>> instance FromValue 'PGint2 UserId where fromValue = UserId <$> fromValue @'PGint2
249 -- >>> 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)
250 -- >>> instance Generic UserRow
757 -- >>> instance Generic UserRow
251 -- >>> instance HasDatatypeInfo UserRow
758 -- >>> instance HasDatatypeInfo UserRow
252 -- >>> type User = '["userId" ::: 'NotNull 'PGint2, "userName" ::: 'Null 'PGtext]
759 -- >>> type User = '["userId" ::: 'NotNull 'PGint2, "userName" ::: 'Null 'PGtext]
253 -- >>> fromRow @User @UserRow (K (Just "\NUL\SOH") :* K (Just "bloodninja") :* Nil)
760 -- >>> fromRow @User @UserRow (K (Just "\NUL\SOH") :* K (Just "bloodninja") :* Nil)
254− -- UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"}
761+ -- Right (UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"})
255− fromRow :: NP (K (Maybe Strict.ByteString)) results -> y
762+ fromRow :: NP (K (Maybe Strict.ByteString)) result -> Either Strict.Text y
256instance
763instance
257− ( SListI results
764+ ( SListI result
258− , IsProductType y ys
765+ , IsRecord y ys
259− , AllZip FromColumnValue results ys
766+ , AllZip FromField result ys
260− , SameFields (DatatypeInfoOf y) results
261− ) => FromRow results y where
767+ ) => FromRow result y where
262 fromRow
768 fromRow
263− = 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)
264
819
265-- | `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
266-- `toParams` or decoding a single value with `fromRow`.
821-- `toParams` or decoding a single value with `fromRow`.
@@ -270,8 +825,24 @@ instance
270-- K (Just "foo") :* Nil
825-- K (Just "foo") :* Nil
271--
826--
272-- >>> fromRow @'["fromOnly" ::: 'Null 'PGtext] @(Only (Maybe Text)) (K (Just "bar") :* Nil)
827-- >>> fromRow @'["fromOnly" ::: 'Null 'PGtext] @(Only (Maybe Text)) (K (Just "bar") :* Nil)
273−-- Only {fromOnly = Just "bar"}
828+-- Right (Only {fromOnly = Just "bar"})
274newtype Only x = Only { fromOnly :: x }
829newtype Only x = Only { fromOnly :: x }
275 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)
830 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)
276instance Generic (Only x)
831instance Generic (Only x)
277instance 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+29−607
@@ -9,652 +9,74 @@ Squeal data definition language.
9-}
9-}
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12+ AllowAmbiguousTypes
12− ConstraintKinds
13+ , ConstraintKinds
13− , DataKinds
14+ , DeriveAnyClass
14− , DeriveDataTypeable
15 , DeriveGeneric
15 , DeriveGeneric
16+ , DerivingStrategies
16 , FlexibleContexts
17 , FlexibleContexts
17 , FlexibleInstances
18 , FlexibleInstances
18 , GADTs
19 , GADTs
19− , GeneralizedNewtypeDeriving
20− , KindSignatures
21 , LambdaCase
20 , LambdaCase
22 , MultiParamTypeClasses
21 , MultiParamTypeClasses
22+ , OverloadedLabels
23 , OverloadedStrings
23 , OverloadedStrings
24 , RankNTypes
24 , RankNTypes
25 , ScopedTypeVariables
25 , ScopedTypeVariables
26− , StandaloneDeriving
27 , TypeApplications
26 , TypeApplications
28 , TypeInType
27 , TypeInType
29 , TypeOperators
28 , TypeOperators
29+ , UndecidableSuperClasses
30+ , UndecidableInstances
30#-}
31#-}
31
32
32module Squeal.PostgreSQL.Definition
33module Squeal.PostgreSQL.Definition
33− ( -- * Definition
34+ ( -- * Definition
34− Definition (UnsafeDefinition, renderDefinition)
35+ Definition (..)
35 , (>>>)
36 , (>>>)
36− -- * Create
37+ , manipDefinition
37− , createTable
38− , createTableIfNotExists
39− , TableConstraintExpression (..)
40− , Column (..)
41− , check
42− , unique
43− , primaryKey
44− , foreignKey
45− , ForeignKeyed
46− , OnDeleteClause (OnDeleteNoAction, OnDeleteRestrict, OnDeleteCascade)
47− , renderOnDeleteClause
48− , OnUpdateClause (OnUpdateNoAction, OnUpdateRestrict, OnUpdateCascade)
49− , renderOnUpdateClause
50− -- * Drop
51− , dropTable
52− -- * Alter
53− , alterTable
54− , alterTableRename
55− , AlterTable (UnsafeAlterTable, renderAlterTable)
56− , addConstraint
57− , dropConstraint
58− , AddColumn (addColumn)
59− , dropColumn
60− , renameColumn
61− , alterColumn
62− , AlterColumn (UnsafeAlterColumn, renderAlterColumn)
63− , setDefault
64− , dropDefault
65− , setNotNull
66− , dropNotNull
67− , alterType
68 ) where
38 ) where
69
39
70import Control.Category
40import Control.Category
71import Control.DeepSeq
41import Control.DeepSeq
72import Data.ByteString
42import Data.ByteString
73import Data.Monoid
43import Data.Monoid
74−import GHC.TypeLits
75import Prelude hiding ((.), id)
44import Prelude hiding ((.), id)
76
45
77−import qualified Generics.SOP as SOP
78import qualified GHC.Generics as GHC
46import qualified GHC.Generics as GHC
79
47
80−import Squeal.PostgreSQL.Expression
48+import Squeal.PostgreSQL.Manipulation
81import Squeal.PostgreSQL.Render
49import Squeal.PostgreSQL.Render
82import Squeal.PostgreSQL.Schema
50import Squeal.PostgreSQL.Schema
83
51
52+-- $setup
53+-- >>> import Squeal.PostgreSQL
54+
84{-----------------------------------------
55{-----------------------------------------
85statements
56statements
86-----------------------------------------}
57-----------------------------------------}
87
58
88−-- | A `Definition` is a statement that changes the schema of the
59+-- | A `Definition` is a statement that changes the schemas of the
89-- database, like a `createTable`, `dropTable`, or `alterTable` command.
60-- database, like a `createTable`, `dropTable`, or `alterTable` command.
90-- `Definition`s may be composed using the `>>>` operator.
61-- `Definition`s may be composed using the `>>>` operator.
91newtype Definition
62newtype Definition
92− (schema0 :: TablesType)
63+ (schemas0 :: SchemasType)
93− (schema1 :: TablesType)
64+ (schemas1 :: SchemasType)
94 = UnsafeDefinition { renderDefinition :: ByteString }
65 = UnsafeDefinition { renderDefinition :: ByteString }
95 deriving (GHC.Generic,Show,Eq,Ord,NFData)
66 deriving (GHC.Generic,Show,Eq,Ord,NFData)
96
67
68+instance RenderSQL (Definition schemas0 schemas1) where
69+ renderSQL = renderDefinition
70+
97instance Category Definition where
71instance Category Definition where
98 id = UnsafeDefinition ";"
72 id = UnsafeDefinition ";"
99 ddl1 . ddl0 = UnsafeDefinition $
73 ddl1 . ddl0 = UnsafeDefinition $
100− renderDefinition ddl0 <+> renderDefinition ddl1
74+ renderSQL ddl0 <> "\n" <> renderSQL ddl1
101−
75+
102−{-----------------------------------------
76+-- | A `Manipulation` without input or output can be run as a statement
103−CREATE statements
77+-- along with other `Definition`s, by embedding it using `manipDefinition`.
104−-----------------------------------------}
78+manipDefinition
105−
79+ :: Manipulation '[] schemas '[] '[]
106−-- | `createTable` adds a table to the schema.
80+ -- ^ no input or output
107−--
81+ -> Definition schemas schemas
108−-- >>> :set -XOverloadedLabels
82+manipDefinition = UnsafeDefinition . (<> ";") . renderSQL
109−-- >>> :{
110−-- renderDefinition $
111−-- createTable #tab (int `As` #a :* real `As` #b :* Nil) Nil
112−-- :}
113−-- "CREATE TABLE tab (a int, b real);"
114−createTable
115− :: ( KnownSymbol table
116− , columns ~ (col ': cols)
117− , SOP.SListI columns
118− , SOP.SListI constraints )
119− => Alias table -- ^ the name of the table to add
120− -> NP (Aliased TypeExpression) columns
121− -- ^ the names and datatype of each column
122− -> NP (Aliased (TableConstraintExpression schema columns)) constraints
123− -- ^ constraints that must hold for the table
124− -> Definition schema (Create table (constraints :=> columns) schema)
125−createTable table columns constraints = UnsafeDefinition $
126− "CREATE TABLE" <+> renderCreation table columns constraints
127−
128−-- | `createTableIfNotExists` creates a table if it doesn't exist, but does not add it to the schema.
129−-- Instead, the schema already has the table so if the table did not yet exist, the schema was wrong.
130−-- `createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in the `Category` `Definition`.
131−--
132−-- >>> :set -XOverloadedLabels -XTypeApplications
133−-- >>> type Table = '[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGfloat4]
134−-- >>> type Schema = '["tab" ::: Table]
135−-- >>> :{
136−-- renderDefinition
137−-- (createTableIfNotExists #tab (int `As` #a :* real `As` #b :* Nil) Nil :: Definition Schema Schema)
138−-- :}
139−-- "CREATE TABLE IF NOT EXISTS tab (a int, b real);"
140−createTableIfNotExists
141− :: ( Has table schema (constraints :=> columns)
142− , SOP.SListI columns
143− , SOP.SListI constraints )
144− => Alias table -- ^ the name of the table to add
145− -> NP (Aliased TypeExpression) columns
146− -- ^ the names and datatype of each column
147− -> NP (Aliased (TableConstraintExpression schema columns)) constraints
148− -- ^ constraints that must hold for the table
149− -> Definition schema schema
150−createTableIfNotExists table columns constraints = UnsafeDefinition $
151− "CREATE TABLE IF NOT EXISTS"
152− <+> renderCreation table columns constraints
153−
154−-- helper function for `createTable` and `createTableIfNotExists`
155−renderCreation
156− :: ( KnownSymbol table
157− , SOP.SListI columns
158− , SOP.SListI constraints )
159− => Alias table -- ^ the name of the table to add
160− -> NP (Aliased TypeExpression) columns
161− -- ^ the names and datatype of each column
162− -> NP (Aliased (TableConstraintExpression schema columns)) constraints
163− -- ^ constraints that must hold for the table
164− -> ByteString
165−renderCreation table columns constraints = renderAlias table
166− <+> parenthesized
167− ( renderCommaSeparated renderColumnDef columns
168− <> ( case constraints of
169− Nil -> ""
170− _ -> ", " <>
171− renderCommaSeparated renderConstraint constraints ) )
172− <> ";"
173− where
174− renderColumnDef :: Aliased TypeExpression x -> ByteString
175− renderColumnDef (ty `As` column) =
176− renderAlias column <+> renderTypeExpression ty
177− renderConstraint
178− :: Aliased (TableConstraintExpression schema columns) constraint
179− -> ByteString
180− renderConstraint (constraint `As` alias) =
181− "CONSTRAINT" <+> renderAlias alias <+> renderTableConstraintExpression constraint
182−
183−-- | Data types are a way to limit the kind of data that can be stored in a
184−-- table. For many applications, however, the constraint they provide is
185−-- too coarse. For example, a column containing a product price should
186−-- probably only accept positive values. But there is no standard data type
187−-- that accepts only positive numbers. Another issue is that you might want
188−-- to constrain column data with respect to other columns or rows.
189−-- For example, in a table containing product information,
190−-- there should be only one row for each product number.
191−-- `TableConstraint`s give you as much control over the data in your tables
192−-- as you wish. If a user attempts to store data in a column that would
193−-- violate a constraint, an error is raised. This applies
194−-- even if the value came from the default value definition.
195−newtype TableConstraintExpression
196− (schema :: TablesType)
197− (columns :: ColumnsType)
198− (tableConstraint :: TableConstraint)
199− = UnsafeTableConstraintExpression
200− { renderTableConstraintExpression :: ByteString }
201− deriving (GHC.Generic,Show,Eq,Ord,NFData)
202−
203−-- | @Column columns column@ is a witness that `column` is in `columns`.
204−data Column
205− (columns :: ColumnsType)
206− (column :: (Symbol,ColumnType))
207− where
208− Column
209− :: Has column columns ty
210− => Alias column
211− -> Column columns (column ::: ty)
212−
213−-- | Render a `Column`.
214−renderColumn :: Column columns column -> ByteString
215−renderColumn (Column column) = renderAlias column
216−
217−-- | A `check` constraint is the most generic `TableConstraint` type.
218−-- It allows you to specify that the value in a certain column must satisfy
219−-- a Boolean (truth-value) expression.
220−--
221−-- >>> :{
222−-- renderDefinition $
223−-- createTable #tab
224−-- ( (int & notNull) `As` #a :*
225−-- (int & notNull) `As` #b :* Nil )
226−-- ( check (Column #a :* Column #b :* Nil) (#a .> #b) `As` #inequality :* Nil )
227−-- :}
228−-- "CREATE TABLE tab (a int NOT NULL, b int NOT NULL, CONSTRAINT inequality CHECK ((a > b)));"
229−check
230− :: NP (Column columns) subcolumns
231− -> Condition '[table ::: ColumnsToRelation subcolumns] 'Ungrouped '[]
232− -- ^ condition to check
233− -> TableConstraintExpression schema columns ('Check (AliasesOf subcolumns))
234−check _cols condition = UnsafeTableConstraintExpression $
235− "CHECK" <+> parenthesized (renderExpression condition)
236−
237−-- | A `unique` constraint ensure that the data contained in a column,
238−-- or a group of columns, is unique among all the rows in the table.
239−--
240−-- >>> :{
241−-- renderDefinition $
242−-- createTable #tab
243−-- ( int `As` #a :*
244−-- int `As` #b :* Nil )
245−-- ( unique (Column #a :* Column #b :* Nil) `As` #uq_a_b :* Nil )
246−-- :}
247−-- "CREATE TABLE tab (a int, b int, CONSTRAINT uq_a_b UNIQUE (a, b));"
248−unique
249− :: SOP.SListI subcolumns
250− => NP (Column columns) subcolumns
251− -- ^ unique column or group of columns
252− -> TableConstraintExpression schema columns ('Unique (AliasesOf subcolumns))
253−unique columns = UnsafeTableConstraintExpression $
254− "UNIQUE" <+> parenthesized (renderCommaSeparated renderColumn columns)
255−
256−-- | A `primaryKey` constraint indicates that a column, or group of columns,
257−-- can be used as a unique identifier for rows in the table.
258−-- This requires that the values be both unique and not null.
259−--
260−-- >>> :{
261−-- renderDefinition $
262−-- createTable #tab
263−-- ( serial `As` #id :*
264−-- (text & notNull) `As` #name :* Nil )
265−-- ( primaryKey (Column #id :* Nil) `As` #pk_id :* Nil )
266−-- :}
267−-- "CREATE TABLE tab (id serial, name text NOT NULL, CONSTRAINT pk_id PRIMARY KEY (id));"
268−primaryKey
269− :: (SOP.SListI subcolumns, AllNotNull subcolumns)
270− => NP (Column columns) subcolumns
271− -- ^ identifying column or group of columns
272− -> TableConstraintExpression schema columns ('PrimaryKey (AliasesOf subcolumns))
273−primaryKey columns = UnsafeTableConstraintExpression $
274− "PRIMARY KEY" <+> parenthesized (renderCommaSeparated renderColumn columns)
275−
276−-- | A `foreignKey` specifies that the values in a column
277−-- (or a group of columns) must match the values appearing in some row of
278−-- another table. We say this maintains the referential integrity
279−-- between two related tables.
280−--
281−-- >>> :{
282−-- type Schema =
283−-- '[ "users" :::
284−-- '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
285−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4
286−-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext
287−-- ]
288−-- , "emails" :::
289−-- '[ "pk_emails" ::: 'PrimaryKey '["id"]
290−-- , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
291−-- ] :=>
292−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4
293−-- , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
294−-- , "email" ::: 'NoDef :=> 'Null 'PGtext
295−-- ]
296−-- ]
297−-- :}
298−--
299−-- >>> :{
300−-- let
301−-- setup :: Definition '[] Schema
302−-- setup =
303−-- createTable #users
304−-- ( serial `As` #id :*
305−-- (text & notNull) `As` #name :* Nil )
306−-- ( primaryKey (Column #id :* Nil) `As` #pk_users :* Nil ) >>>
307−-- createTable #emails
308−-- ( serial `As` #id :*
309−-- (int & notNull) `As` #user_id :*
310−-- text `As` #email :* Nil )
311−-- ( primaryKey (Column #id :* Nil) `As` #pk_emails :*
312−-- foreignKey (Column #user_id :* Nil) #users (Column #id :* Nil)
313−-- OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )
314−-- in renderDefinition setup
315−-- :}
316−-- "CREATE TABLE users (id serial, name text NOT NULL, CONSTRAINT pk_users PRIMARY KEY (id)); CREATE TABLE emails (id serial, user_id int NOT NULL, email text, CONSTRAINT pk_emails PRIMARY KEY (id), CONSTRAINT fk_user_id FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE ON UPDATE CASCADE);"
317−foreignKey
318− :: ForeignKeyed schema table reftable subcolumns refsubcolumns
319− => NP (Column columns) subcolumns
320− -- ^ column or columns in the table
321− -> Alias table
322− -- ^ reference table
323− -> NP (Column (TableToColumns reftable)) refsubcolumns
324− -- ^ reference column or columns in the reference table
325− -> OnDeleteClause
326− -- ^ what to do when reference is deleted
327− -> OnUpdateClause
328− -- ^ what to do when reference is updated
329− -> TableConstraintExpression schema columns
330− ('ForeignKey (AliasesOf subcolumns) table (AliasesOf refsubcolumns))
331−foreignKey columns reftable refcolumns onDelete onUpdate =
332− UnsafeTableConstraintExpression $
333− "FOREIGN KEY" <+> parenthesized (renderCommaSeparated renderColumn columns)
334− <+> "REFERENCES" <+> renderAlias reftable
335− <+> parenthesized (renderCommaSeparated renderColumn refcolumns)
336− <+> renderOnDeleteClause onDelete
337− <+> renderOnUpdateClause onUpdate
338−
339−-- | A type synonym for constraints on a table with a foreign key.
340−type ForeignKeyed schema table reftable subcolumns refsubcolumns
341− = ( Has table schema reftable
342− , SameTypes subcolumns refsubcolumns
343− , AllNotNull subcolumns
344− , SOP.SListI subcolumns
345− , SOP.SListI refsubcolumns )
346−
347−-- | `OnDeleteClause` indicates what to do with rows that reference a deleted row.
348−data OnDeleteClause
349− = OnDeleteNoAction
350− -- ^ if any referencing rows still exist when the constraint is checked,
351− -- an error is raised
352− | OnDeleteRestrict -- ^ prevents deletion of a referenced row
353− | OnDeleteCascade
354− -- ^ specifies that when a referenced row is deleted,
355− -- row(s) referencing it should be automatically deleted as well
356− deriving (GHC.Generic,Show,Eq,Ord)
357−instance NFData OnDeleteClause
358−
359−-- | Render `OnDeleteClause`.
360−renderOnDeleteClause :: OnDeleteClause -> ByteString
361−renderOnDeleteClause = \case
362− OnDeleteNoAction -> "ON DELETE NO ACTION"
363− OnDeleteRestrict -> "ON DELETE RESTRICT"
364− OnDeleteCascade -> "ON DELETE CASCADE"
365−
366−-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked
367−-- when a referenced column is changed (updated).
368−data OnUpdateClause
369− = OnUpdateNoAction
370− -- ^ if any referencing rows has not changed when the constraint is checked,
371− -- an error is raised
372− | OnUpdateRestrict -- ^ prevents update of a referenced row
373− | OnUpdateCascade
374− -- ^ the updated values of the referenced column(s) should be copied
375− -- into the referencing row(s)
376− deriving (GHC.Generic,Show,Eq,Ord)
377−instance NFData OnUpdateClause
378−
379−-- | Render `OnUpdateClause`.
380−renderOnUpdateClause :: OnUpdateClause -> ByteString
381−renderOnUpdateClause = \case
382− OnUpdateNoAction -> "ON UPDATE NO ACTION"
383− OnUpdateRestrict -> "ON UPDATE RESTRICT"
384− OnUpdateCascade -> "ON UPDATE CASCADE"
385−
386−{-----------------------------------------
387−DROP statements
388−-----------------------------------------}
389−
390−-- | `dropTable` removes a table from the schema.
391−--
392−-- >>> renderDefinition $ dropTable #muh_table
393−-- "DROP TABLE muh_table;"
394−dropTable
395− :: KnownSymbol table
396− => Alias table -- ^ table to remove
397− -> Definition schema (Drop table schema)
398−dropTable table = UnsafeDefinition $ "DROP TABLE" <+> renderAlias table <> ";"
399−
400−{-----------------------------------------
401−ALTER statements
402−-----------------------------------------}
403−
404−-- | `alterTable` changes the definition of a table from the schema.
405−alterTable
406− :: Has tab schema table0
407− => Alias tab -- ^ table to alter
408− -> AlterTable schema table0 table1 -- ^ alteration to perform
409− -> Definition schema (Alter tab schema table1)
410−alterTable table alteration = UnsafeDefinition $
411− "ALTER TABLE"
412− <+> renderAlias table
413− <+> renderAlterTable alteration
414− <> ";"
415−
416−-- | `alterTableRename` changes the name of a table from the schema.
417−--
418−-- >>> renderDefinition $ alterTableRename #foo #bar
419−-- "ALTER TABLE foo RENAME TO bar;"
420−alterTableRename
421− :: (KnownSymbol table0, KnownSymbol table1)
422− => Alias table0 -- ^ table to rename
423− -> Alias table1 -- ^ what to rename it
424− -> Definition schema (Rename table0 table1 schema)
425−alterTableRename table0 table1 = UnsafeDefinition $
426− "ALTER TABLE" <+> renderAlias table0
427− <+> "RENAME TO" <+> renderAlias table1 <> ";"
428−
429−-- | An `AlterTable` describes the alteration to perform on the columns
430−-- of a table.
431−newtype AlterTable
432− (schema :: TablesType)
433− (table0 :: TableType)
434− (table1 :: TableType) =
435− UnsafeAlterTable {renderAlterTable :: ByteString}
436− deriving (GHC.Generic,Show,Eq,Ord,NFData)
437−
438−-- | An `addConstraint` adds a table constraint.
439−--
440−-- >>> :{
441−-- let
442−-- definition :: Definition
443−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4]]
444−-- '["tab" ::: '["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4]]
445−-- definition = alterTable #tab (addConstraint #positive (check (Column #col :* Nil) (#col .> 0)))
446−-- in renderDefinition definition
447−-- :}
448−-- "ALTER TABLE tab ADD CONSTRAINT positive CHECK ((col > 0));"
449−addConstraint
450− :: KnownSymbol alias
451− => Alias alias
452− -> TableConstraintExpression schema columns constraint
453− -- ^ constraint to add
454− -> AlterTable schema (constraints :=> columns)
455− (Create alias constraint constraints :=> columns)
456−addConstraint alias constraint = UnsafeAlterTable $
457− "ADD" <+> "CONSTRAINT" <+> renderAlias alias
458− <+> renderTableConstraintExpression constraint
459−
460−-- | A `dropConstraint` drops a table constraint.
461−--
462−-- >>> :{
463−-- let
464−-- definition :: Definition
465−-- '["tab" ::: '["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4]]
466−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4]]
467−-- definition = alterTable #tab (dropConstraint #positive)
468−-- in renderDefinition definition
469−-- :}
470−-- "ALTER TABLE tab DROP CONSTRAINT positive;"
471−dropConstraint
472− :: KnownSymbol constraint
473− => Alias constraint
474− -- ^ constraint to drop
475− -> AlterTable schema
476− (constraints :=> columns)
477− (Drop constraint constraints :=> columns)
478−dropConstraint constraint = UnsafeAlterTable $
479− "DROP" <+> "CONSTRAINT" <+> renderAlias constraint
480−
481−-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.
482−class AddColumn ty where
483− -- | `addColumn` adds a new column, initially filled with whatever
484− -- default value is given or with @NULL@.
485− --
486− -- >>> :{
487− -- let
488− -- definition :: Definition
489− -- '["tab" ::: '[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4]]
490− -- '["tab" ::: '[] :=>
491− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
492− -- , "col2" ::: 'Def :=> 'Null 'PGtext ]]
493− -- definition = alterTable #tab (addColumn #col2 (text & default_ "foo"))
494− -- in renderDefinition definition
495− -- :}
496− -- "ALTER TABLE tab ADD COLUMN col2 text DEFAULT E'foo';"
497− --
498− -- >>> :{
499− -- let
500− -- definition :: Definition
501− -- '["tab" ::: '[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4]]
502− -- '["tab" ::: '[] :=>
503− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
504− -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ]]
505− -- definition = alterTable #tab (addColumn #col2 text)
506− -- in renderDefinition definition
507− -- :}
508− -- "ALTER TABLE tab ADD COLUMN col2 text;"
509− addColumn
510− :: KnownSymbol column
511− => Alias column -- ^ column to add
512− -> TypeExpression ty -- ^ type of the new column
513− -> AlterTable schema (constraints :=> columns)
514− (constraints :=> Create column ty columns)
515− addColumn column ty = UnsafeAlterTable $
516− "ADD COLUMN" <+> renderAlias column <+> renderTypeExpression ty
517−instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)
518−instance {-# OVERLAPPABLE #-} AddColumn ('NoDef :=> 'Null ty)
519−
520−-- | A `dropColumn` removes a column. Whatever data was in the column
521−-- disappears. Table constraints involving the column are dropped, too.
522−-- However, if the column is referenced by a foreign key constraint of
523−-- another table, PostgreSQL will not silently drop that constraint.
524−--
525−-- >>> :{
526−-- let
527−-- definition :: Definition
528−-- '["tab" ::: '[] :=>
529−-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
530−-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ]]
531−-- '["tab" ::: '[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4]]
532−-- definition = alterTable #tab (dropColumn #col2)
533−-- in renderDefinition definition
534−-- :}
535−-- "ALTER TABLE tab DROP COLUMN col2;"
536−dropColumn
537− :: KnownSymbol column
538− => Alias column -- ^ column to remove
539− -> AlterTable schema
540− (constraints :=> columns)
541− (DropIfConstraintsInvolve column constraints :=> Drop column columns)
542−dropColumn column = UnsafeAlterTable $
543− "DROP COLUMN" <+> renderAlias column
544−
545−-- | A `renameColumn` renames a column.
546−--
547−-- >>> :{
548−-- let
549−-- definition :: Definition
550−-- '["tab" ::: '[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4]]
551−-- '["tab" ::: '[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4]]
552−-- definition = alterTable #tab (renameColumn #foo #bar)
553−-- in renderDefinition definition
554−-- :}
555−-- "ALTER TABLE tab RENAME COLUMN foo TO bar;"
556−renameColumn
557− :: (KnownSymbol column0, KnownSymbol column1)
558− => Alias column0 -- ^ column to rename
559− -> Alias column1 -- ^ what to rename the column
560− -> AlterTable schema (constraints :=> columns)
561− (constraints :=> Rename column0 column1 columns)
562−renameColumn column0 column1 = UnsafeAlterTable $
563− "RENAME COLUMN" <+> renderAlias column0 <+> "TO" <+> renderAlias column1
564−
565−-- | An `alterColumn` alters a single column.
566−alterColumn
567− :: (KnownSymbol column, Has column columns ty0)
568− => Alias column -- ^ column to alter
569− -> AlterColumn ty0 ty1 -- ^ alteration to perform
570− -> AlterTable schema (constraints :=> columns)
571− (constraints :=> Alter column columns ty1)
572−alterColumn column alteration = UnsafeAlterTable $
573− "ALTER COLUMN" <+> renderAlias column <+> renderAlterColumn alteration
574−
575−-- | An `AlterColumn` describes the alteration to perform on a single column.
576−newtype AlterColumn (ty0 :: ColumnType) (ty1 :: ColumnType) =
577− UnsafeAlterColumn {renderAlterColumn :: ByteString}
578− deriving (GHC.Generic,Show,Eq,Ord,NFData)
579−
580−-- | A `setDefault` sets a new default for a column. Note that this doesn't
581−-- affect any existing rows in the table, it just changes the default for
582−-- future insert and update commands.
583−--
584−-- >>> :{
585−-- let
586−-- definition :: Definition
587−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
588−-- '["tab" ::: '[] :=> '["col" ::: 'Def :=> 'Null 'PGint4]]
589−-- definition = alterTable #tab (alterColumn #col (setDefault 5))
590−-- in renderDefinition definition
591−-- :}
592−-- "ALTER TABLE tab ALTER COLUMN col SET DEFAULT 5;"
593−setDefault
594− :: Expression '[] 'Ungrouped '[] ty -- ^ default value to set
595− -> AlterColumn (constraint :=> ty) ('Def :=> ty)
596−setDefault expression = UnsafeAlterColumn $
597− "SET DEFAULT" <+> renderExpression expression
598−
599−-- | A `dropDefault` removes any default value for a column.
600−--
601−-- >>> :{
602−-- let
603−-- definition :: Definition
604−-- '["tab" ::: '[] :=> '["col" ::: 'Def :=> 'Null 'PGint4]]
605−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
606−-- definition = alterTable #tab (alterColumn #col dropDefault)
607−-- in renderDefinition definition
608−-- :}
609−-- "ALTER TABLE tab ALTER COLUMN col DROP DEFAULT;"
610−dropDefault :: AlterColumn ('Def :=> ty) ('NoDef :=> ty)
611−dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"
612−
613−-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.
614−-- The constraint will be checked immediately, so the table data must satisfy
615−-- the constraint before it can be added.
616−--
617−-- >>> :{
618−-- let
619−-- definition :: Definition
620−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
621−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4]]
622−-- definition = alterTable #tab (alterColumn #col setNotNull)
623−-- in renderDefinition definition
624−-- :}
625−-- "ALTER TABLE tab ALTER COLUMN col SET NOT NULL;"
626−setNotNull
627− :: AlterColumn (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)
628−setNotNull = UnsafeAlterColumn $ "SET NOT NULL"
629−
630−-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.
631−--
632−-- >>> :{
633−-- let
634−-- definition :: Definition
635−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4]]
636−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
637−-- definition = alterTable #tab (alterColumn #col dropNotNull)
638−-- in renderDefinition definition
639−-- :}
640−-- "ALTER TABLE tab ALTER COLUMN col DROP NOT NULL;"
641−dropNotNull
642− :: AlterColumn (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)
643−dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"
644−
645−-- | An `alterType` converts a column to a different data type.
646−-- This will succeed only if each existing entry in the column can be
647−-- converted to the new type by an implicit cast.
648−--
649−-- >>> :{
650−-- let
651−-- definition :: Definition
652−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4]]
653−-- '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric]]
654−-- definition =
655−-- alterTable #tab (alterColumn #col (alterType (numeric & notNull)))
656−-- in renderDefinition definition
657−-- :}
658−-- "ALTER TABLE tab ALTER COLUMN col TYPE numeric NOT NULL;"
659−alterType :: TypeExpression ty -> AlterColumn ty0 ty
660−alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderTypeExpression ty
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+364−1095
@@ -1,19 +1,17 @@
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− , DataKinds
13+ , ConstraintKinds
15 , DeriveGeneric
14 , DeriveGeneric
16− , DeriveDataTypeable
17 , FlexibleContexts
15 , FlexibleContexts
18 , FlexibleInstances
16 , FlexibleInstances
19 , FunctionalDependencies
17 , FunctionalDependencies
@@ -22,8 +20,6 @@ Squeal expressions are the atoms used to build statements.
22 , LambdaCase
20 , LambdaCase
23 , MagicHash
21 , MagicHash
24 , OverloadedStrings
22 , OverloadedStrings
25− , PolyKinds
26− , RankNTypes
27 , ScopedTypeVariables
23 , ScopedTypeVariables
28 , StandaloneDeriving
24 , StandaloneDeriving
29 , TypeApplications
25 , TypeApplications
@@ -31,364 +27,356 @@ Squeal expressions are the atoms used to build statements.
31 , TypeInType
27 , TypeInType
32 , TypeOperators
28 , TypeOperators
33 , UndecidableInstances
29 , UndecidableInstances
30+ , RankNTypes
34#-}
31#-}
35
32
36−module Squeal.PostgreSQL.Expression
33+module Squeal.PostgreSQL.Expression
37 ( -- * Expression
34 ( -- * Expression
38− Expression (UnsafeExpression, renderExpression)
35+ Expression (..)
39− , HasParameter (param)
36+ , Expr
40− -- ** Null
37+ , type (-->)
41− , null_
38+ , FunctionDB
42− , unNull
43− , coalesce
44− , fromNull
45− , isNull
46− , isn'tNull
47− , matchNull
48− , nullIf
49− -- ** Arrays
50− , array
51− -- ** Functions
52− , unsafeBinaryOp
53− , unsafeUnaryOp
54 , unsafeFunction
39 , unsafeFunction
55− , atan2_
40+ , function
56− , cast
41+ , unsafeLeftOp
57− , quot_
42+ , leftOp
58− , rem_
43+ , unsafeRightOp
59− , trunc
44+ , rightOp
60− , round_
45+ , Operator
61− , ceiling_
46+ , OperatorDB
62− , greatest
47+ , unsafeBinaryOp
63− , least
48+ , binaryOp
64− -- ** Conditions
49+ , FunctionVar
65− , Condition
50+ , unsafeFunctionVar
66− , true
51+ , type (--->)
67− , false
52+ , FunctionNDB
68− , not_
53+ , unsafeFunctionN
69− , (.&&)
54+ , functionN
70− , (.||)
55+ , PGSubset (..)
71− , caseWhenThenElse
56+ , PGIntersect (..)
72− , ifThenElse
73− , (.==)
74− , (./=)
75− , (.>=)
76− , (.<)
77− , (.<=)
78− , (.>)
79− -- ** Time
80− , currentDate
81− , currentTime
82− , currentTimestamp
83− , localTime
84− , localTimestamp
85− -- ** Text
86− , lower
87− , upper
88− , charLength
89− , like
90− -- ** Aggregation
91− , unsafeAggregate, unsafeAggregateDistinct
92− , sum_, sumDistinct
93− , PGAvg (avg, avgDistinct)
94− , bitAnd, bitOr, boolAnd, boolOr
95− , bitAndDistinct, bitOrDistinct, boolAndDistinct, boolOrDistinct
96− , countStar
97− , count, countDistinct
98− , every, everyDistinct
99− , max_, maxDistinct, min_, minDistinct
100− -- * Tables
101− , Table (UnsafeTable, renderTable)
102− -- * Types
103− , TypeExpression (UnsafeTypeExpression, renderTypeExpression)
104− , PGTyped (pgtype)
105− , bool
106− , int2
107− , smallint
108− , int4
109− , int
110− , integer
111− , int8
112− , bigint
113− , numeric
114− , float4
115− , real
116− , float8
117− , doublePrecision
118− , serial2
119− , smallserial
120− , serial4
121− , serial
122− , serial8
123− , bigserial
124− , text
125− , char
126− , character
127− , varchar
128− , characterVarying
129− , bytea
130− , timestamp
131− , timestampWithTimeZone
132− , date
133− , time
134− , timeWithTimeZone
135− , interval
136− , uuid
137− , inet
138− , json
139− , jsonb
140− , vararray
141− , fixarray
142− , notNull
143− , default_
144 -- * Re-export
57 -- * Re-export
145 , (&)
58 , (&)
146− , NP ((:*), Nil)
59+ , K (..)
60+ , unK
147 ) where
61 ) where
148
62
149import Control.Category
63import Control.Category
150import Control.DeepSeq
64import Control.DeepSeq
151import Data.ByteString (ByteString)
65import Data.ByteString (ByteString)
152import Data.Function ((&))
66import Data.Function ((&))
153−import Data.Monoid hiding (All)
67+import Data.Semigroup hiding (All)
154−import Data.Ratio
155import Data.String
68import Data.String
156−import Generics.SOP hiding (from)
69+import Generics.SOP hiding (All, from)
157import GHC.OverloadedLabels
70import GHC.OverloadedLabels
158import GHC.TypeLits
71import GHC.TypeLits
72+import Numeric
159import Prelude hiding (id, (.))
73import Prelude hiding (id, (.))
160
74
161import qualified GHC.Generics as GHC
75import qualified GHC.Generics as GHC
162
76
77+import Squeal.PostgreSQL.Alias
78+import Squeal.PostgreSQL.List
163import Squeal.PostgreSQL.Render
79import Squeal.PostgreSQL.Render
164import Squeal.PostgreSQL.Schema
80import Squeal.PostgreSQL.Schema
165
81
82+-- $setup
83+-- >>> import Squeal.PostgreSQL
84+
166{-----------------------------------------
85{-----------------------------------------
167column expressions
86column expressions
168-----------------------------------------}
87-----------------------------------------}
169
88
170{- | `Expression`s are used in a variety of contexts,
89{- | `Expression`s are used in a variety of contexts,
171−such as in the target list of the `select` command,
90+such as in the target `Squeal.PostgreSQL.Query.List` of the
91+`Squeal.PostgreSQL.Query.select` command,
172−as new column values in `insertInto` or `update`,
92+as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or
93+`Squeal.PostgreSQL.Manipulation.update`,
173−or in search `Condition`s in a number of commands.
94+or in search `Squeal.PostgreSQL.Logic.Condition`s in a number of commands.
174
95
175The expression syntax allows the calculation of
96The expression syntax allows the calculation of
176values from primitive expression using arithmetic, logical,
97values from primitive expression using arithmetic, logical,
177and 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`.
178-}
113-}
179newtype Expression
114newtype Expression
180− (relations :: RelationsType)
115+ (outer :: FromType)
116+ (commons :: FromType)
181− (grouping :: Grouping)
117+ (grp :: Grouping)
118+ (schemas :: SchemasType)
182 (params :: [NullityType])
119 (params :: [NullityType])
120+ (from :: FromType)
183 (ty :: NullityType)
121 (ty :: NullityType)
184 = UnsafeExpression { renderExpression :: ByteString }
122 = UnsafeExpression { renderExpression :: ByteString }
185 deriving (GHC.Generic,Show,Eq,Ord,NFData)
123 deriving (GHC.Generic,Show,Eq,Ord,NFData)
186−
124+instance RenderSQL (Expression outer commons grp schemas params from ty) where
187−{- | A `HasParameter` constraint is used to indicate a value that is
125+ renderSQL = renderExpression
188−supplied externally to a SQL statement.
126+
189−`Squeal.PostgreSQL.PQ.manipulateParams`,
127+-- | An `Expr` is a closed `Expression`.
190−`Squeal.PostgreSQL.PQ.queryParams` and
128+-- It is a F@RankNType@ but don't be scared.
191−`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values
129+-- Think of it as an expression which sees no
192−separately from the SQL command string, in which case `param`s are used to
130+-- namespaces, so you can't use parameters
193−refer to the out-of-line data values.
131+-- or alias references. It can be used as
132+-- a simple piece of more complex `Expression`s.
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)
194-}
181-}
195−class (PGTyped (PGTypeOf ty), KnownNat n) => HasParameter
182+type (--->) xs y
196− (n :: Nat)
183+ = forall outer commons grp schemas params from
197− (params :: [NullityType])
184+ . NP (Expression outer commons grp schemas params from) xs
198− (ty :: NullityType)
185+ -- ^ inputs
199− | n params -> ty where
186+ -> Expression outer commons grp schemas params from y
200− param :: Expression relations grouping params ty
187+ -- ^ output
188+
189+type FunctionNDB schemas xs y
190+ = forall outer commons grp params from
191+ . NP (Expression outer commons grp schemas params from) xs
192+ -- ^ inputs
193+ -> Expression outer commons grp schemas params from y
194+ -- ^ output
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
201− param = UnsafeExpression $ parenthesized $
212+unsafeFunctionVar fun xs x = UnsafeExpression $ fun <> parenthesized
202− "$" <> renderNat (Proxy @n) <+> "::"
213+ (commaSeparated (renderSQL <$> xs) <> ", " <> renderSQL x)
203− <+> renderTypeExpression (pgtype @(PGTypeOf ty))
214+
204−instance {-# OVERLAPPING #-} PGTyped (PGTypeOf ty1)
215+instance (HasUnique tab (Join outer from) row, Has col row ty)
205− => HasParameter 1 (ty1:tys) ty1
216+ => IsLabel col (Expression outer commons 'Ungrouped schemas params from ty) where
206−instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) params ty)
217+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)
207− => HasParameter n (ty' : params) ty
218+instance (HasUnique tab (Join outer from) row, Has col row ty, tys ~ '[ty])
208−
219+ => IsLabel col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where
209−instance (HasUnique relation relations columns, Has column columns ty)
220+ fromLabel = fromLabel @col :* Nil
221+instance (HasUnique tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))
222+ => IsLabel col
223+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where
224+ fromLabel = fromLabel @col `As` Alias
225+instance (HasUnique tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])
226+ => IsLabel col
227+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where
228+ fromLabel = fromLabel @col :* Nil
229+
230+instance (Has tab (Join outer from) row, Has col row ty)
231+ => IsQualified tab col (Expression outer commons 'Ungrouped schemas params from ty) where
232+ tab ! col = UnsafeExpression $
233+ renderSQL tab <> "." <> renderSQL col
234+instance (Has tab (Join outer from) row, Has col row ty, tys ~ '[ty])
235+ => IsQualified tab col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where
236+ tab ! col = tab ! col :* Nil
237+instance (Has tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))
238+ => IsQualified tab col
239+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where
240+ tab ! col = tab ! col `As` col
241+instance (Has tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])
242+ => IsQualified tab col
210− => IsLabel column (Expression relations 'Ungrouped params ty) where
243+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where
211− fromLabel = UnsafeExpression $ renderAlias (Alias @column)
244+ tab ! col = tab ! col :* Nil
212
245
213−instance (Has relation relations columns, Has column columns ty)
214− => IsQualified relation column (Expression relations 'Ungrouped params ty) where
215− relation ! column = UnsafeExpression $
216− renderAlias relation <> "." <> renderAlias column
217−
218instance
246instance
219− ( HasUnique relation relations columns
247+ ( HasUnique tab (Join outer from) row
220− , Has column columns ty
248+ , Has col row ty
221− , GroupedBy relation column bys
249+ , GroupedBy tab col bys
222− ) => IsLabel column
250+ ) => IsLabel col
223− (Expression relations ('Grouped bys) params ty) where
251+ (Expression outer commons ('Grouped bys) schemas params from ty) where
224− fromLabel = UnsafeExpression $ renderAlias (Alias @column)
252+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)
225−
226instance
253instance
227− ( Has relation relations columns
254+ ( HasUnique tab (Join outer from) row
228− , Has column columns ty
255+ , Has col row ty
229− , GroupedBy relation column bys
256+ , GroupedBy tab col bys
230− ) => IsQualified relation column
257+ , tys ~ '[ty]
258+ ) => IsLabel col
231− (Expression relations ('Grouped bys) params ty) where
259+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where
232− relation ! column = UnsafeExpression $
260+ fromLabel = fromLabel @col :* Nil
233− renderAlias relation <> "." <> renderAlias column
261+instance
234−
262+ ( HasUnique tab (Join outer from) row
235−-- | analagous to `Nothing`
263+ , Has col row ty
236−--
264+ , GroupedBy tab col bys
237−-- >>> renderExpression $ null_
265+ , column ~ (col ::: ty)
238−-- "NULL"
266+ ) => IsLabel col
239−null_ :: Expression relations grouping params ('Null ty)
267+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where
240−null_ = UnsafeExpression "NULL"
268+ fromLabel = fromLabel @col `As` Alias
241−
269+instance
242−-- | analagous to `Just`
270+ ( HasUnique tab (Join outer from) row
243−--
271+ , Has col row ty
244−-- >>> renderExpression $ unNull true
272+ , GroupedBy tab col bys
245−-- "TRUE"
273+ , columns ~ '[col ::: ty]
246−unNull
274+ ) => IsLabel col
247− :: Expression relations grouping params ('NotNull ty)
275+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where
248− -- ^ not @NULL@
276+ fromLabel = fromLabel @col :* Nil
249− -> Expression relations grouping params ('Null ty)
250−unNull = UnsafeExpression . renderExpression
251−
252−-- | return the leftmost value which is not NULL
253−--
254−-- >>> renderExpression $ coalesce [null_, unNull true] false
255−-- "COALESCE(NULL, TRUE, FALSE)"
256−coalesce
257− :: [Expression relations grouping params ('Null ty)]
258− -- ^ @NULL@s may be present
259− -> Expression relations grouping params ('NotNull ty)
260− -- ^ @NULL@ is absent
261− -> Expression relations grouping params ('NotNull ty)
262−coalesce nullxs notNullx = UnsafeExpression $
263− "COALESCE" <> parenthesized (commaSeparated
264− ((renderExpression <$> nullxs) <> [renderExpression notNullx]))
265−
266−-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@
267−--
268−-- >>> renderExpression $ fromNull true null_
269−-- "COALESCE(NULL, TRUE)"
270−fromNull
271− :: Expression relations grouping params ('NotNull ty)
272− -- ^ what to convert @NULL@ to
273− -> Expression relations grouping params ('Null ty)
274− -> Expression relations grouping params ('NotNull ty)
275−fromNull notNullx nullx = coalesce [nullx] notNullx
276−
277−-- | >>> renderExpression $ null_ & isNull
278−-- "NULL IS NULL"
279−isNull
280− :: Expression relations grouping params ('Null ty)
281− -- ^ possibly @NULL@
282− -> Condition relations grouping params
283−isNull x = UnsafeExpression $ renderExpression x <+> "IS NULL"
284−
285−-- | >>> renderExpression $ null_ & isn'tNull
286−-- "NULL IS NOT NULL"
287−isn'tNull
288− :: Expression relations grouping params ('Null ty)
289− -- ^ possibly @NULL@
290− -> Condition relations grouping params
291−isn'tNull x = UnsafeExpression $ renderExpression x <+> "IS NOT NULL"
292−
293−-- | analagous to `maybe` using @IS NULL@
294−--
295−-- >>> renderExpression $ matchNull true not_ null_
296−-- "CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END"
297−matchNull
298− :: Expression relations grouping params (nullty)
299− -- ^ what to convert @NULL@ to
300− -> ( Expression relations grouping params ('NotNull ty)
301− -> Expression relations grouping params (nullty) )
302− -- ^ function to perform when @NULL@ is absent
303− -> Expression relations grouping params ('Null ty)
304− -> Expression relations grouping params (nullty)
305−matchNull y f x = ifThenElse (isNull x) y
306− (f (UnsafeExpression (renderExpression x)))
307−
308−-- | right inverse to `fromNull`, if its arguments are equal then
309−-- `nullIf` gives @NULL@.
310−--
311−-- >>> :set -XTypeApplications -XDataKinds
312−-- >>> renderExpression @_ @_ @'[_] $ fromNull false (nullIf false (param @1))
313−-- "COALESCE(NULL IF (FALSE, ($1 :: bool)), FALSE)"
314−nullIf
315− :: Expression relations grouping params ('NotNull ty)
316− -- ^ @NULL@ is absent
317− -> Expression relations grouping params ('NotNull ty)
318− -- ^ @NULL@ is absent
319− -> Expression relations grouping params ('Null ty)
320−nullIf x y = UnsafeExpression $ "NULL IF" <+> parenthesized
321− (renderExpression x <> ", " <> renderExpression y)
322−
323−-- | >>> renderExpression $ array [null_, unNull false, unNull true]
324−-- "ARRAY[NULL, FALSE, TRUE]"
325−array
326− :: [Expression relations grouping params ('Null ty)]
327− -- ^ array elements
328− -> Expression relations grouping params (nullity ('PGvararray ty))
329−array xs = UnsafeExpression $
330− "ARRAY[" <> commaSeparated (renderExpression <$> xs) <> "]"
331−
332−instance Monoid
333− (Expression relations grouping params (nullity ('PGvararray ty))) where
334− mempty = array []
335− mappend = unsafeBinaryOp "||"
336−
337−-- | >>> renderExpression @_ @_ @'[_] $ greatest currentTimestamp [param @1]
338−-- "GREATEST(CURRENT_TIMESTAMP, ($1 :: timestamp with time zone))"
339−greatest
340− :: Expression relations grouping params (nullty)
341− -- ^ needs at least 1 argument
342− -> [Expression relations grouping params (nullty)]
343− -- ^ or more
344− -> Expression relations grouping params (nullty)
345−greatest x xs = UnsafeExpression $ "GREATEST("
346− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"
347−
348−-- | >>> renderExpression $ least currentTimestamp [null_]
349−-- "LEAST(CURRENT_TIMESTAMP, NULL)"
350−least
351− :: Expression relations grouping params (nullty)
352− -- ^ needs at least 1 argument
353− -> [Expression relations grouping params (nullty)]
354− -- ^ or more
355− -> Expression relations grouping params (nullty)
356−least x xs = UnsafeExpression $ "LEAST("
357− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"
358
277
278+instance
279+ ( Has tab (Join outer from) row
280+ , Has col row ty
281+ , GroupedBy tab col bys
282+ ) => IsQualified tab col
283+ (Expression outer commons ('Grouped bys) schemas params from ty) where
284+ tab ! col = UnsafeExpression $
285+ renderSQL tab <> "." <> renderSQL col
286+instance
287+ ( Has tab (Join outer from) row
288+ , Has col row ty
289+ , GroupedBy tab col bys
290+ , tys ~ '[ty]
291+ ) => IsQualified tab col
292+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where
293+ tab ! col = tab ! col :* Nil
294+instance
295+ ( Has tab (Join outer from) row
296+ , Has col row ty
297+ , GroupedBy tab col bys
298+ , column ~ (col ::: ty)
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
308+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where
309+ tab ! col = tab ! col :* Nil
310+
311+instance (KnownSymbol label, label `In` labels) => IsPGlabel label
312+ (Expression outer commons grp schemas params from (null ('PGenum labels))) where
313+ label = UnsafeExpression $ renderSQL (PGlabel @label)
314+
359−-- | >>> renderExpression $ unsafeBinaryOp "OR" true false
315+-- | >>> printSQL $ unsafeBinaryOp "OR" true false
360−-- "(TRUE OR FALSE)"
316+-- (TRUE OR FALSE)
361−unsafeBinaryOp
317+unsafeBinaryOp :: ByteString -> Operator ty0 ty1 ty2
362− :: ByteString
363− -- ^ operator
364− -> Expression relations grouping params (ty0)
365− -> Expression relations grouping params (ty1)
366− -> Expression relations grouping params (ty2)
367unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $
318unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $
368− renderExpression x <+> op <+> renderExpression y
319+ renderSQL x <+> op <+> renderSQL y
369−
320+
370−-- | >>> renderExpression $ unsafeUnaryOp "NOT" true
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
327+
328+-- | >>> printSQL $ unsafeLeftOp "NOT" true
371−-- "(NOT TRUE)"
329+-- (NOT TRUE)
372−unsafeUnaryOp
373− :: ByteString
330+unsafeLeftOp :: ByteString -> x --> y
374− -- ^ operator
331+unsafeLeftOp op x = UnsafeExpression $ parenthesized $ op <+> renderSQL x
375− -> Expression relations grouping params (ty0)
332+
376− -> Expression 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
377−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $
343+unsafeRightOp op x = UnsafeExpression $ parenthesized $ renderSQL x <+> op
378− op <+> renderExpression x
344+
379−
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
351+
380−-- | >>> renderExpression $ unsafeFunction "f" true
352+-- | >>> printSQL $ unsafeFunction "f" true
381−-- "f(TRUE)"
353+-- f(TRUE)
382−unsafeFunction
354+unsafeFunction :: ByteString -> x --> y
383− :: ByteString
384− -- ^ function
385− -> Expression relations grouping params (xty)
386− -> Expression relations grouping params (yty)
387unsafeFunction fun x = UnsafeExpression $
355unsafeFunction fun x = UnsafeExpression $
388− fun <> parenthesized (renderExpression x)
356+ fun <> parenthesized (renderSQL x)
389−
357+
358+function
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')
366+unsafeFunctionN :: SListI xs => ByteString -> xs ---> y
367+unsafeFunctionN fun xs = UnsafeExpression $
368+ fun <> parenthesized (renderCommaSeparated renderSQL xs)
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+
390−instance PGNum ty
378+instance ty `In` PGNum
391− => Num (Expression relations grouping params (nullity ty)) where
379+ => Num (Expression outer commons grp schemas params from (null ty)) where
392 (+) = unsafeBinaryOp "+"
380 (+) = unsafeBinaryOp "+"
393 (-) = unsafeBinaryOp "-"
381 (-) = unsafeBinaryOp "-"
394 (*) = unsafeBinaryOp "*"
382 (*) = unsafeBinaryOp "*"
@@ -399,19 +387,24 @@ instance PGNum ty
399 . fromString
387 . fromString
400 . show
388 . show
401
389
402−instance (PGNum ty, PGFloating ty) => Fractional
390+instance (ty `In` PGNum, ty `In` PGFloating) => Fractional
403− (Expression relations grouping params (nullity ty)) where
391+ (Expression outer commons grp schemas params from (null ty)) where
404 (/) = unsafeBinaryOp "/"
392 (/) = unsafeBinaryOp "/"
405− fromRational x = fromInteger (numerator x) / fromInteger (denominator x)
393+ fromRational
394+ = UnsafeExpression
395+ . fromString
396+ . ($ "")
397+ . showFFloat Nothing
398+ . fromRat @Double
406
399
407−instance (PGNum ty, PGFloating ty) => Floating
400+instance (ty `In` PGNum, ty `In` PGFloating) => Floating
408− (Expression relations grouping params (nullity ty)) where
401+ (Expression outer commons grp schemas params from (null ty)) where
409 pi = UnsafeExpression "pi()"
402 pi = UnsafeExpression "pi()"
410 exp = unsafeFunction "exp"
403 exp = unsafeFunction "exp"
411 log = unsafeFunction "ln"
404 log = unsafeFunction "ln"
412 sqrt = unsafeFunction "sqrt"
405 sqrt = unsafeFunction "sqrt"
413 b ** x = UnsafeExpression $
406 b ** x = UnsafeExpression $
414− "power(" <> renderExpression b <> ", " <> renderExpression x <> ")"
407+ "power(" <> renderSQL b <> ", " <> renderSQL x <> ")"
415 logBase b y = log y / log b
408 logBase b y = log y / log b
416 sin = unsafeFunction "sin"
409 sin = unsafeFunction "sin"
417 cos = unsafeFunction "cos"
410 cos = unsafeFunction "cos"
@@ -426,778 +419,54 @@ instance (PGNum ty, PGFloating ty) => Floating
426 acosh x = log (x + sqrt (x*x - 1))
419 acosh x = log (x + sqrt (x*x - 1))
427 atanh x = log ((1 + x) / (1 - x)) / 2
420 atanh x = log ((1 + x) / (1 - x)) / 2
428
421
429−-- | >>> :{
422+-- | Contained by operators
430−-- let
423+class PGSubset ty where
431−-- expression :: Expression relations grouping params (nullity 'PGfloat4)
424+ (@>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
432−-- expression = atan2_ pi 2
425+ (@>) = unsafeBinaryOp "@>"
433−-- in renderExpression expression
426+ (<@) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
434−-- :}
427+ (<@) = unsafeBinaryOp "<@"
435−-- "atan2(pi(), 2)"
428+instance PGSubset 'PGjsonb
436−atan2_
429+instance PGSubset 'PGtsquery
437− :: PGFloating float
430+instance PGSubset ('PGvararray ty)
438− => Expression relations grouping params (nullity float)
431+instance PGSubset ('PGrange ty)
439− -- ^ numerator
432+
440− -> Expression relations grouping params (nullity float)
433+class PGIntersect ty where
441− -- ^ denominator
434+ (@&&) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)
442− -> Expression relations grouping params (nullity float)
435+ (@&&) = unsafeBinaryOp "&&"
443−atan2_ y x = UnsafeExpression $
436+instance PGIntersect ('PGvararray ty)
444− "atan2(" <> renderExpression y <> ", " <> renderExpression x <> ")"
437+instance PGIntersect ('PGrange ty)
445−
446−-- When a `cast` is applied to an `Expression` of a known type, it
447−-- represents a run-time type conversion. The cast will succeed only if a
448−-- suitable type conversion operation has been defined.
449−--
450−-- | >>> renderExpression $ true & cast int4
451−-- "(TRUE :: int4)"
452−cast
453− :: TypeExpression ('NoDef :=> 'Null ty1)
454− -- ^ type to cast as
455− -> Expression relations grouping params (nullity ty0)
456− -- ^ value to convert
457− -> Expression relations grouping params (nullity ty1)
458−cast ty x = UnsafeExpression $ parenthesized $
459− renderExpression x <+> "::" <+> renderTypeExpression ty
460−
461−-- | integer division, truncates the result
462−--
463−-- >>> :{
464−-- let
465−-- expression :: Expression relations grouping params (nullity 'PGint2)
466−-- expression = 5 `quot_` 2
467−-- in renderExpression expression
468−-- :}
469−-- "(5 / 2)"
470−quot_
471− :: PGIntegral int
472− => Expression relations grouping params (nullity int)
473− -- ^ numerator
474− -> Expression relations grouping params (nullity int)
475− -- ^ denominator
476− -> Expression relations grouping params (nullity int)
477−quot_ = unsafeBinaryOp "/"
478−
479−-- | remainder upon integer division
480−--
481−-- >>> :{
482−-- let
483−-- expression :: Expression relations grouping params (nullity 'PGint2)
484−-- expression = 5 `rem_` 2
485−-- in renderExpression expression
486−-- :}
487−-- "(5 % 2)"
488−rem_
489− :: PGIntegral int
490− => Expression relations grouping params (nullity int)
491− -- ^ numerator
492− -> Expression relations grouping params (nullity int)
493− -- ^ denominator
494− -> Expression relations grouping params (nullity int)
495−rem_ = unsafeBinaryOp "%"
496−
497−-- | >>> :{
498−-- let
499−-- expression :: Expression relations grouping params (nullity 'PGfloat4)
500−-- expression = trunc pi
501−-- in renderExpression expression
502−-- :}
503−-- "trunc(pi())"
504−trunc
505− :: PGFloating frac
506− => Expression relations grouping params (nullity frac)
507− -- ^ fractional number
508− -> Expression relations grouping params (nullity frac)
509−trunc = unsafeFunction "trunc"
510−
511−-- | >>> :{
512−-- let
513−-- expression :: Expression relations grouping params (nullity 'PGfloat4)
514−-- expression = round_ pi
515−-- in renderExpression expression
516−-- :}
517−-- "round(pi())"
518−round_
519− :: PGFloating frac
520− => Expression relations grouping params (nullity frac)
521− -- ^ fractional number
522− -> Expression relations grouping params (nullity frac)
523−round_ = unsafeFunction "round"
524−
525−-- | >>> :{
526−-- let
527−-- expression :: Expression relations grouping params (nullity 'PGfloat4)
528−-- expression = ceiling_ pi
529−-- in renderExpression expression
530−-- :}
531−-- "ceiling(pi())"
532−ceiling_
533− :: PGFloating frac
534− => Expression relations grouping params (nullity frac)
535− -- ^ fractional number
536− -> Expression relations grouping params (nullity frac)
537−ceiling_ = unsafeFunction "ceiling"
538−
539−-- | A `Condition` is a boolean valued `Expression`. While SQL allows
540−-- conditions to have @NULL@, Squeal instead chooses to disallow @NULL@,
541−-- forcing one to handle the case of @NULL@ explicitly to produce
542−-- a `Condition`.
543−type Condition relations grouping params =
544− Expression relations grouping params ('NotNull 'PGbool)
545−
546−-- | >>> renderExpression true
547−-- "TRUE"
548−true :: Condition relations grouping params
549−true = UnsafeExpression "TRUE"
550−
551−-- | >>> renderExpression false
552−-- "FALSE"
553−false :: Condition relations grouping params
554−false = UnsafeExpression "FALSE"
555−
556−-- | >>> renderExpression $ not_ true
557−-- "(NOT TRUE)"
558−not_
559− :: Condition relations grouping params
560− -> Condition relations grouping params
561−not_ = unsafeUnaryOp "NOT"
562−
563−-- | >>> renderExpression $ true .&& false
564−-- "(TRUE AND FALSE)"
565−(.&&)
566− :: Condition relations grouping params
567− -> Condition relations grouping params
568− -> Condition relations grouping params
569−(.&&) = unsafeBinaryOp "AND"
570−
571−-- | >>> renderExpression $ true .|| false
572−-- "(TRUE OR FALSE)"
573−(.||)
574− :: Condition relations grouping params
575− -> Condition relations grouping params
576− -> Condition relations grouping params
577−(.||) = unsafeBinaryOp "OR"
578−
579−-- | >>> :{
580−-- let
581−-- expression :: Expression relations grouping params (nullity 'PGint2)
582−-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3
583−-- in renderExpression expression
584−-- :}
585−-- "CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END"
586−caseWhenThenElse
587− :: [ ( Condition relations grouping params
588− , Expression relations grouping params (ty)
589− ) ]
590− -- ^ whens and thens
591− -> Expression relations grouping params (ty)
592− -- ^ else
593− -> Expression relations grouping params (ty)
594−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat
595− [ "CASE"
596− , mconcat
597− [ mconcat
598− [ " WHEN ", renderExpression when_
599− , " THEN ", renderExpression then_
600− ]
601− | (when_,then_) <- whenThens
602− ]
603− , " ELSE ", renderExpression else_
604− , " END"
605− ]
606−
607−-- | >>> :{
608−-- let
609−-- expression :: Expression relations grouping params (nullity 'PGint2)
610−-- expression = ifThenElse true 1 0
611−-- in renderExpression expression
612−-- :}
613−-- "CASE WHEN TRUE THEN 1 ELSE 0 END"
614−ifThenElse
615− :: Condition relations grouping params
616− -> Expression relations grouping params (ty) -- ^ then
617− -> Expression relations grouping params (ty) -- ^ else
618− -> Expression relations grouping params (ty)
619−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_
620−
621−-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`
622−-- will produce @NULL@s if one of their arguments is @NULL@.
623−--
624−-- >>> renderExpression $ unNull true .== null_
625−-- "(TRUE = NULL)"
626−(.==)
627− :: Expression relations grouping params (nullity ty) -- ^ lhs
628− -> Expression relations grouping params (nullity ty) -- ^ rhs
629− -> Expression relations grouping params (nullity 'PGbool)
630−(.==) = unsafeBinaryOp "="
631−infix 4 .==
632−
633−-- | >>> renderExpression $ unNull true ./= null_
634−-- "(TRUE <> NULL)"
635−(./=)
636− :: Expression relations grouping params (nullity ty) -- ^ lhs
637− -> Expression relations grouping params (nullity ty) -- ^ rhs
638− -> Expression relations grouping params (nullity 'PGbool)
639−(./=) = unsafeBinaryOp "<>"
640−infix 4 ./=
641−
642−-- | >>> renderExpression $ unNull true .>= null_
643−-- "(TRUE >= NULL)"
644−(.>=)
645− :: Expression relations grouping params (nullity ty) -- ^ lhs
646− -> Expression relations grouping params (nullity ty) -- ^ rhs
647− -> Expression relations grouping params (nullity 'PGbool)
648−(.>=) = unsafeBinaryOp ">="
649−infix 4 .>=
650−
651−-- | >>> renderExpression $ unNull true .< null_
652−-- "(TRUE < NULL)"
653−(.<)
654− :: Expression relations grouping params (nullity ty) -- ^ lhs
655− -> Expression relations grouping params (nullity ty) -- ^ rhs
656− -> Expression relations grouping params (nullity 'PGbool)
657−(.<) = unsafeBinaryOp "<"
658−infix 4 .<
659−
660−-- | >>> renderExpression $ unNull true .<= null_
661−-- "(TRUE <= NULL)"
662−(.<=)
663− :: Expression relations grouping params (nullity ty) -- ^ lhs
664− -> Expression relations grouping params (nullity ty) -- ^ rhs
665− -> Expression relations grouping params (nullity 'PGbool)
666−(.<=) = unsafeBinaryOp "<="
667−infix 4 .<=
668−
669−-- | >>> renderExpression $ unNull true .> null_
670−-- "(TRUE > NULL)"
671−(.>)
672− :: Expression relations grouping params (nullity ty) -- ^ lhs
673− -> Expression relations grouping params (nullity ty) -- ^ rhs
674− -> Expression relations grouping params (nullity 'PGbool)
675−(.>) = unsafeBinaryOp ">"
676−infix 4 .>
677−
678−-- | >>> renderExpression currentDate
679−-- "CURRENT_DATE"
680−currentDate
681− :: Expression relations grouping params (nullity 'PGdate)
682−currentDate = UnsafeExpression "CURRENT_DATE"
683−
684−-- | >>> renderExpression currentTime
685−-- "CURRENT_TIME"
686−currentTime
687− :: Expression relations grouping params (nullity 'PGtimetz)
688−currentTime = UnsafeExpression "CURRENT_TIME"
689−
690−-- | >>> renderExpression currentTimestamp
691−-- "CURRENT_TIMESTAMP"
692−currentTimestamp
693− :: Expression relations grouping params (nullity 'PGtimestamptz)
694−currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"
695−
696−-- | >>> renderExpression localTime
697−-- "LOCALTIME"
698−localTime
699− :: Expression relations grouping params (nullity 'PGtime)
700−localTime = UnsafeExpression "LOCALTIME"
701−
702−-- | >>> renderExpression localTimestamp
703−-- "LOCALTIMESTAMP"
704−localTimestamp
705− :: Expression relations grouping params (nullity 'PGtimestamp)
706−localTimestamp = UnsafeExpression "LOCALTIMESTAMP"
707−
708−{-----------------------------------------
709−text
710−-----------------------------------------}
711
438
712instance IsString
439instance IsString
713− (Expression relations grouping params (nullity 'PGtext)) where
440+ (Expression outer commons grp schemas params from (null 'PGtext)) where
714 fromString str = UnsafeExpression $
441 fromString str = UnsafeExpression $
715 "E\'" <> fromString (escape =<< str) <> "\'"
442 "E\'" <> fromString (escape =<< str) <> "\'"
716− where
443+instance IsString
717− escape = \case
444+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where
718− '\NUL' -> "\\0"
445+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsvector") $
719− '\'' -> "''"
446+ "E\'" <> fromString (escape =<< str) <> "\'"
720− '"' -> "\\\""
447+instance IsString
721− '\b' -> "\\b"
448+ (Expression outer commons grp schemas params from (null 'PGtsquery)) where
722− '\n' -> "\\n"
449+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsquery") $
723− '\r' -> "\\r"
450+ "E\'" <> fromString (escape =<< str) <> "\'"
724− '\t' -> "\\t"
451+
725− '\\' -> "\\\\"
452+instance Semigroup
726− c -> [c]
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
463+ (<>) = unsafeBinaryOp "||"
727
464
728instance Monoid
465instance Monoid
729− (Expression relations grouping params (nullity 'PGtext)) where
466+ (Expression outer commons grp schemas params from (null 'PGtext)) where
730 mempty = fromString ""
467 mempty = fromString ""
731− mappend = unsafeBinaryOp "||"
468+ mappend = (<>)
732−
469+instance Monoid
733−-- | >>> renderExpression $ lower "ARRRGGG"
470+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where
734−-- "lower(E'ARRRGGG')"
471+ mempty = fromString ""
735−lower
472+ mappend = (<>)
736− :: Expression relations grouping params (nullity 'PGtext)
737− -- ^ string to lower case
738− -> Expression relations grouping params (nullity 'PGtext)
739−lower = unsafeFunction "lower"
740−
741−-- | >>> renderExpression $ upper "eeee"
742−-- "upper(E'eeee')"
743−upper
744− :: Expression relations grouping params (nullity 'PGtext)
745− -- ^ string to upper case
746− -> Expression relations grouping params (nullity 'PGtext)
747−upper = unsafeFunction "upper"
748−
749−-- | >>> renderExpression $ charLength "four"
750−-- "char_length(E'four')"
751−charLength
752− :: Expression relations grouping params (nullity 'PGtext)
753− -- ^ string to measure
754− -> Expression relations grouping params (nullity 'PGint4)
755−charLength = unsafeFunction "char_length"
756−
757−-- | The `like` expression returns true if the @string@ matches
758−-- the supplied @pattern@. If @pattern@ does not contain percent signs
759−-- or underscores, then the pattern only represents the string itself;
760−-- in that case `like` acts like the equals operator. An underscore (_)
761−-- in pattern stands for (matches) any single character; a percent sign (%)
762−-- matches any sequence of zero or more characters.
763−--
764−-- >>> renderExpression $ "abc" `like` "a%"
765−-- "(E'abc' LIKE E'a%')"
766−like
767− :: Expression relations grouping params (nullity 'PGtext)
768− -- ^ string
769− -> Expression relations grouping params (nullity 'PGtext)
770− -- ^ pattern
771− -> Expression relations grouping params (nullity 'PGbool)
772−like = unsafeBinaryOp "LIKE"
773−
774−{-----------------------------------------
775−aggregation
776−-----------------------------------------}
777−
778−-- | escape hatch to define aggregate functions
779−unsafeAggregate
780− :: ByteString -- ^ aggregate function
781− -> Expression relations 'Ungrouped params (xty)
782− -> Expression relations ('Grouped bys) params (yty)
783−unsafeAggregate fun x = UnsafeExpression $ mconcat
784− [fun, "(", renderExpression x, ")"]
785−
786−-- | escape hatch to define aggregate functions over distinct values
787−unsafeAggregateDistinct
788− :: ByteString -- ^ aggregate function
789− -> Expression relations 'Ungrouped params (xty)
790− -> Expression relations ('Grouped bys) params (yty)
791−unsafeAggregateDistinct fun x = UnsafeExpression $ mconcat
792− [fun, "(DISTINCT ", renderExpression x, ")"]
793−
794−-- | >>> :{
795−-- let
796−-- expression :: Expression '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Grouped bys) params ('Null 'PGnumeric)
797−-- expression = sum_ #col
798−-- in renderExpression expression
799−-- :}
800−-- "sum(col)"
801−sum_
802− :: PGNum ty
803− => Expression relations 'Ungrouped params (nullity ty)
804− -- ^ what to sum
805− -> Expression relations ('Grouped bys) params (nullity ty)
806−sum_ = unsafeAggregate "sum"
807−
808−-- | >>> :{
809−-- let
810−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGnumeric]] ('Grouped bys) params (nullity 'PGnumeric)
811−-- expression = sumDistinct #col
812−-- in renderExpression expression
813−-- :}
814−-- "sum(DISTINCT col)"
815−sumDistinct
816− :: PGNum ty
817− => Expression relations 'Ungrouped params (nullity ty)
818− -- ^ what to sum
819− -> Expression relations ('Grouped bys) params (nullity ty)
820−sumDistinct = unsafeAggregateDistinct "sum"
821−
822−-- | A constraint for `PGType`s that you can take averages of and the resulting
823−-- `PGType`.
824−class PGAvg ty avg | ty -> avg where
825− avg, avgDistinct
826− :: Expression relations 'Ungrouped params (nullity ty)
827− -- ^ what to average
828− -> Expression relations ('Grouped bys) params (nullity avg)
829− avg = unsafeAggregate "avg"
830− avgDistinct = unsafeAggregateDistinct "avg"
831−instance PGAvg 'PGint2 'PGnumeric
832−instance PGAvg 'PGint4 'PGnumeric
833−instance PGAvg 'PGint8 'PGnumeric
834−instance PGAvg 'PGnumeric 'PGnumeric
835−instance PGAvg 'PGfloat4 'PGfloat8
836−instance PGAvg 'PGfloat8 'PGfloat8
837−instance PGAvg 'PGinterval 'PGinterval
838−
839−-- | >>> :{
840−-- let
841−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
842−-- expression = bitAnd #col
843−-- in renderExpression expression
844−-- :}
845−-- "bit_and(col)"
846−bitAnd
847− :: PGIntegral int
848− => Expression relations 'Ungrouped params (nullity int)
849− -- ^ what to aggregate
850− -> Expression relations ('Grouped bys) params (nullity int)
851−bitAnd = unsafeAggregate "bit_and"
852−
853−-- | >>> :{
854−-- let
855−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
856−-- expression = bitOr #col
857−-- in renderExpression expression
858−-- :}
859−-- "bit_or(col)"
860−bitOr
861− :: PGIntegral int
862− => Expression relations 'Ungrouped params (nullity int)
863− -- ^ what to aggregate
864− -> Expression relations ('Grouped bys) params (nullity int)
865−bitOr = unsafeAggregate "bit_or"
866−
867−-- | >>> :{
868−-- let
869−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
870−-- expression = bitAndDistinct #col
871−-- in renderExpression expression
872−-- :}
873−-- "bit_and(DISTINCT col)"
874−bitAndDistinct
875− :: PGIntegral int
876− => Expression relations 'Ungrouped params (nullity int)
877− -- ^ what to aggregate
878− -> Expression relations ('Grouped bys) params (nullity int)
879−bitAndDistinct = unsafeAggregateDistinct "bit_and"
880−
881−-- | >>> :{
882−-- let
883−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)
884−-- expression = bitOrDistinct #col
885−-- in renderExpression expression
886−-- :}
887−-- "bit_or(DISTINCT col)"
888−bitOrDistinct
889− :: PGIntegral int
890− => Expression relations 'Ungrouped params (nullity int)
891− -- ^ what to aggregate
892− -> Expression relations ('Grouped bys) params (nullity int)
893−bitOrDistinct = unsafeAggregateDistinct "bit_or"
894−
895−-- | >>> :{
896−-- let
897−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
898−-- expression = boolAnd #col
899−-- in renderExpression expression
900−-- :}
901−-- "bool_and(col)"
902−boolAnd
903− :: Expression relations 'Ungrouped params (nullity 'PGbool)
904− -- ^ what to aggregate
905− -> Expression relations ('Grouped bys) params (nullity 'PGbool)
906−boolAnd = unsafeAggregate "bool_and"
907−
908−-- | >>> :{
909−-- let
910−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
911−-- expression = boolOr #col
912−-- in renderExpression expression
913−-- :}
914−-- "bool_or(col)"
915−boolOr
916− :: Expression relations 'Ungrouped params (nullity 'PGbool)
917− -- ^ what to aggregate
918− -> Expression relations ('Grouped bys) params (nullity 'PGbool)
919−boolOr = unsafeAggregate "bool_or"
920−
921−-- | >>> :{
922−-- let
923−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
924−-- expression = boolAndDistinct #col
925−-- in renderExpression expression
926−-- :}
927−-- "bool_and(DISTINCT col)"
928−boolAndDistinct
929− :: Expression relations 'Ungrouped params (nullity 'PGbool)
930− -- ^ what to aggregate
931− -> Expression relations ('Grouped bys) params (nullity 'PGbool)
932−boolAndDistinct = unsafeAggregateDistinct "bool_and"
933−
934−-- | >>> :{
935−-- let
936−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
937−-- expression = boolOrDistinct #col
938−-- in renderExpression expression
939−-- :}
940−-- "bool_or(DISTINCT col)"
941−boolOrDistinct
942− :: Expression relations 'Ungrouped params (nullity 'PGbool)
943− -- ^ what to aggregate
944− -> Expression relations ('Grouped bys) params (nullity 'PGbool)
945−boolOrDistinct = unsafeAggregateDistinct "bool_or"
946−
947−-- | A special aggregation that does not require an input
948−--
949−-- >>> renderExpression countStar
950−-- "count(*)"
951−countStar
952− :: Expression relations ('Grouped bys) params ('NotNull 'PGint8)
953−countStar = UnsafeExpression $ "count(*)"
954−
955−-- | >>> :{
956−-- let
957−-- expression :: Expression '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)
958−-- expression = count #col
959−-- in renderExpression expression
960−-- :}
961−-- "count(col)"
962−count
963− :: Expression relations 'Ungrouped params ty
964− -- ^ what to count
965− -> Expression relations ('Grouped bys) params ('NotNull 'PGint8)
966−count = unsafeAggregate "count"
967−
968−-- | >>> :{
969−-- let
970−-- expression :: Expression '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)
971−-- expression = countDistinct #col
972−-- in renderExpression expression
973−-- :}
974−-- "count(DISTINCT col)"
975−countDistinct
976− :: Expression relations 'Ungrouped params ty
977− -- ^ what to count
978− -> Expression relations ('Grouped bys) params ('NotNull 'PGint8)
979−countDistinct = unsafeAggregateDistinct "count"
980−
981−-- | synonym for `boolAnd`
982−--
983−-- >>> :{
984−-- let
985−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
986−-- expression = every #col
987−-- in renderExpression expression
988−-- :}
989−-- "every(col)"
990−every
991− :: Expression relations 'Ungrouped params (nullity 'PGbool)
992− -- ^ what to aggregate
993− -> Expression relations ('Grouped bys) params (nullity 'PGbool)
994−every = unsafeAggregate "every"
995−
996−-- | synonym for `boolAndDistinct`
997−--
998−-- >>> :{
999−-- let
1000−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)
1001−-- expression = everyDistinct #col
1002−-- in renderExpression expression
1003−-- :}
1004−-- "every(DISTINCT col)"
1005−everyDistinct
1006− :: Expression relations 'Ungrouped params (nullity 'PGbool)
1007− -- ^ what to aggregate
1008− -> Expression relations ('Grouped bys) params (nullity 'PGbool)
1009−everyDistinct = unsafeAggregateDistinct "every"
1010−
1011−-- | minimum and maximum aggregation
1012−max_, min_, maxDistinct, minDistinct
1013− :: Expression relations 'Ungrouped params (nullity ty)
1014− -- ^ what to aggregate
1015− -> Expression relations ('Grouped bys) params (nullity ty)
1016−max_ = unsafeAggregate "max"
1017−min_ = unsafeAggregate "min"
1018−maxDistinct = unsafeAggregateDistinct "max"
1019−minDistinct = unsafeAggregateDistinct "min"
1020−
1021−{-----------------------------------------
1022−tables
1023−-----------------------------------------}
1024−
1025−-- | A `Table` from a table expression is a way
1026−-- to call a table reference by its alias.
1027−newtype Table
1028− (schema :: TablesType)
1029− (columns :: RelationType)
1030− = UnsafeTable { renderTable :: ByteString }
1031− deriving (GHC.Generic,Show,Eq,Ord,NFData)
1032−instance
1033− ( Has alias schema table
1034− , relation ~ ColumnsToRelation (TableToColumns table)
1035− ) => IsLabel alias (Table schema relation) where
1036− fromLabel = UnsafeTable $ renderAlias (Alias @alias)
1037−
1038−{-----------------------------------------
1039−type expressions
1040−-----------------------------------------}
1041−
1042−-- | `TypeExpression`s are used in `cast`s and `createTable` commands.
1043−newtype TypeExpression (ty :: ColumnType)
1044− = UnsafeTypeExpression { renderTypeExpression :: ByteString }
1045− deriving (GHC.Generic,Show,Eq,Ord,NFData)
1046−
1047−-- | logical Boolean (true/false)
1048−bool :: TypeExpression ('NoDef :=> 'Null 'PGbool)
1049−bool = UnsafeTypeExpression "bool"
1050−-- | signed two-byte integer
1051−int2, smallint :: TypeExpression ('NoDef :=> 'Null 'PGint2)
1052−int2 = UnsafeTypeExpression "int2"
1053−smallint = UnsafeTypeExpression "smallint"
1054−-- | signed four-byte integer
1055−int4, int, integer :: TypeExpression ('NoDef :=> 'Null 'PGint4)
1056−int4 = UnsafeTypeExpression "int4"
1057−int = UnsafeTypeExpression "int"
1058−integer = UnsafeTypeExpression "integer"
1059−-- | signed eight-byte integer
1060−int8, bigint :: TypeExpression ('NoDef :=> 'Null 'PGint8)
1061−int8 = UnsafeTypeExpression "int8"
1062−bigint = UnsafeTypeExpression "bigint"
1063−-- | arbitrary precision numeric type
1064−numeric :: TypeExpression ('NoDef :=> 'Null 'PGnumeric)
1065−numeric = UnsafeTypeExpression "numeric"
1066−-- | single precision floating-point number (4 bytes)
1067−float4, real :: TypeExpression ('NoDef :=> 'Null 'PGfloat4)
1068−float4 = UnsafeTypeExpression "float4"
1069−real = UnsafeTypeExpression "real"
1070−-- | double precision floating-point number (8 bytes)
1071−float8, doublePrecision :: TypeExpression ('NoDef :=> 'Null 'PGfloat8)
1072−float8 = UnsafeTypeExpression "float8"
1073−doublePrecision = UnsafeTypeExpression "double precision"
1074−-- | not a true type, but merely a notational convenience for creating
1075−-- unique identifier columns with type `'PGint2`
1076−serial2, smallserial
1077− :: TypeExpression ('Def :=> 'NotNull 'PGint2)
1078−serial2 = UnsafeTypeExpression "serial2"
1079−smallserial = UnsafeTypeExpression "smallserial"
1080−-- | not a true type, but merely a notational convenience for creating
1081−-- unique identifier columns with type `'PGint4`
1082−serial4, serial
1083− :: TypeExpression ('Def :=> 'NotNull 'PGint4)
1084−serial4 = UnsafeTypeExpression "serial4"
1085−serial = UnsafeTypeExpression "serial"
1086−-- | not a true type, but merely a notational convenience for creating
1087−-- unique identifier columns with type `'PGint8`
1088−serial8, bigserial
1089− :: TypeExpression ('Def :=> 'NotNull 'PGint8)
1090−serial8 = UnsafeTypeExpression "serial8"
1091−bigserial = UnsafeTypeExpression "bigserial"
1092−-- | variable-length character string
1093−text :: TypeExpression ('NoDef :=> 'Null 'PGtext)
1094−text = UnsafeTypeExpression "text"
1095−-- | fixed-length character string
1096−char, character
1097− :: (KnownNat n, 1 <= n)
1098− => proxy n
1099− -> TypeExpression ('NoDef :=> 'Null ('PGchar n))
1100−char p = UnsafeTypeExpression $ "char(" <> renderNat p <> ")"
1101−character p = UnsafeTypeExpression $ "character(" <> renderNat p <> ")"
1102−-- | variable-length character string
1103−varchar, characterVarying
1104− :: (KnownNat n, 1 <= n)
1105− => proxy n
1106− -> TypeExpression ('NoDef :=> 'Null ('PGvarchar n))
1107−varchar p = UnsafeTypeExpression $ "varchar(" <> renderNat p <> ")"
1108−characterVarying p = UnsafeTypeExpression $
1109− "character varying(" <> renderNat p <> ")"
1110−-- | binary data ("byte array")
1111−bytea :: TypeExpression ('NoDef :=> 'Null 'PGbytea)
1112−bytea = UnsafeTypeExpression "bytea"
1113−-- | date and time (no time zone)
1114−timestamp :: TypeExpression ('NoDef :=> 'Null 'PGtimestamp)
1115−timestamp = UnsafeTypeExpression "timestamp"
1116−-- | date and time, including time zone
1117−timestampWithTimeZone :: TypeExpression ('NoDef :=> 'Null 'PGtimestamptz)
1118−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"
1119−-- | calendar date (year, month, day)
1120−date :: TypeExpression ('NoDef :=> 'Null 'PGdate)
1121−date = UnsafeTypeExpression "date"
1122−-- | time of day (no time zone)
1123−time :: TypeExpression ('NoDef :=> 'Null 'PGtime)
1124−time = UnsafeTypeExpression "time"
1125−-- | time of day, including time zone
1126−timeWithTimeZone :: TypeExpression ('NoDef :=> 'Null 'PGtimetz)
1127−timeWithTimeZone = UnsafeTypeExpression "time with time zone"
1128−-- | time span
1129−interval :: TypeExpression ('NoDef :=> 'Null 'PGinterval)
1130−interval = UnsafeTypeExpression "interval"
1131−-- | universally unique identifier
1132−uuid :: TypeExpression ('NoDef :=> 'Null 'PGuuid)
1133−uuid = UnsafeTypeExpression "uuid"
1134−-- | IPv4 or IPv6 host address
1135−inet :: TypeExpression ('NoDef :=> 'Null 'PGinet)
1136−inet = UnsafeTypeExpression "inet"
1137−-- | textual JSON data
1138−json :: TypeExpression ('NoDef :=> 'Null 'PGjson)
1139−json = UnsafeTypeExpression "json"
1140−-- | binary JSON data, decomposed
1141−jsonb :: TypeExpression ('NoDef :=> 'Null 'PGjsonb)
1142−jsonb = UnsafeTypeExpression "jsonb"
1143−-- | variable length array
1144−vararray
1145− :: TypeExpression ('NoDef :=> 'Null pg)
1146− -> TypeExpression ('NoDef :=> 'Null ('PGvararray pg))
1147−vararray ty = UnsafeTypeExpression $ renderTypeExpression ty <> "[]"
1148−-- | fixed length array
1149−--
1150−-- >>> renderTypeExpression (fixarray (Proxy @2) json)
1151−-- "json[2]"
1152−fixarray
1153− :: KnownNat n
1154− => proxy n
1155− -> TypeExpression ('NoDef :=> 'Null pg)
1156− -> TypeExpression ('NoDef :=> 'Null ('PGfixarray n pg))
1157−fixarray p ty = UnsafeTypeExpression $
1158− renderTypeExpression ty <> "[" <> renderNat p <> "]"
1159−
1160−-- | used in `createTable` commands as a column constraint to ensure
1161−-- @NULL@ is not present
1162−notNull
1163− :: TypeExpression (def :=> 'Null ty)
1164− -> TypeExpression (def :=> 'NotNull ty)
1165−notNull ty = UnsafeTypeExpression $ renderTypeExpression ty <+> "NOT NULL"
1166−
1167−-- | used in `createTable` commands as a column constraint to give a default
1168−default_
1169− :: Expression '[] 'Ungrouped '[] ty
1170− -> TypeExpression ('NoDef :=> ty)
1171− -> TypeExpression ('Def :=> ty)
1172−default_ x ty = UnsafeTypeExpression $
1173− renderTypeExpression ty <+> "DEFAULT" <+> renderExpression x
1174−
1175−-- | `pgtype` is a demoted version of a `PGType`
1176−class PGTyped (ty :: PGType) where
1177− pgtype :: TypeExpression ('NoDef :=> 'Null ty)
1178−instance PGTyped 'PGbool where pgtype = bool
1179−instance PGTyped 'PGint2 where pgtype = int2
1180−instance PGTyped 'PGint4 where pgtype = int4
1181−instance PGTyped 'PGint8 where pgtype = int8
1182−instance PGTyped 'PGnumeric where pgtype = numeric
1183−instance PGTyped 'PGfloat4 where pgtype = float4
1184−instance PGTyped 'PGfloat8 where pgtype = float8
1185−instance PGTyped 'PGtext where pgtype = text
1186−instance (KnownNat n, 1 <= n)
1187− => PGTyped ('PGchar n) where pgtype = char (Proxy @n)
1188−instance (KnownNat n, 1 <= n)
1189− => PGTyped ('PGvarchar n) where pgtype = varchar (Proxy @n)
1190−instance PGTyped 'PGbytea where pgtype = bytea
1191−instance PGTyped 'PGtimestamp where pgtype = timestamp
1192−instance PGTyped 'PGtimestamptz where pgtype = timestampWithTimeZone
1193−instance PGTyped 'PGdate where pgtype = date
1194−instance PGTyped 'PGtime where pgtype = time
1195−instance PGTyped 'PGtimetz where pgtype = timeWithTimeZone
1196−instance PGTyped 'PGinterval where pgtype = interval
1197−instance PGTyped 'PGuuid where pgtype = uuid
1198−instance PGTyped 'PGjson where pgtype = json
1199−instance PGTyped 'PGjsonb where pgtype = jsonb
1200−instance PGTyped ty => PGTyped ('PGvararray ty) where
1201− pgtype = vararray (pgtype @ty)
1202−instance (KnownNat n, PGTyped ty) => PGTyped ('PGfixarray n ty) where
1203− pgtype = fixarray (Proxy @n) (pgtype @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+427−361
@@ -9,316 +9,371 @@ Squeal data manipulation language.
9-}
9-}
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12− DataKinds
13− , DeriveDataTypeable
14− , DeriveGeneric
12+ DeriveGeneric
15 , FlexibleContexts
13 , FlexibleContexts
14+ , FlexibleInstances
16 , GADTs
15 , GADTs
17 , GeneralizedNewtypeDeriving
16 , GeneralizedNewtypeDeriving
18− , KindSignatures
19 , LambdaCase
17 , LambdaCase
18+ , MultiParamTypeClasses
20 , OverloadedStrings
19 , OverloadedStrings
20+ , PatternSynonyms
21+ , QuantifiedConstraints
21 , RankNTypes
22 , RankNTypes
22− , StandaloneDeriving
23+ , ScopedTypeVariables
24+ , TypeApplications
25+ , TypeFamilies
23 , TypeInType
26 , TypeInType
24 , TypeOperators
27 , TypeOperators
28+ , UndecidableInstances
25#-}
29#-}
26
30
27module Squeal.PostgreSQL.Manipulation
31module Squeal.PostgreSQL.Manipulation
28 ( -- * Manipulation
32 ( -- * Manipulation
33+ Manipulation_
29− Manipulation (UnsafeManipulation, renderManipulation)
34+ , Manipulation (..)
30 , queryStatement
35 , queryStatement
31− , ColumnValue (..)
32− , ReturningClause (ReturningStar, Returning)
33− , ConflictClause (OnConflictDoRaise, OnConflictDoNothing, OnConflictDoUpdate)
34 -- * Insert
36 -- * Insert
35− , insertRows
37+ , insertInto
36− , insertRow
38+ , insertInto_
37− , insertRows_
38− , insertRow_
39− , insertQuery
40− , insertQuery_
41− , renderReturningClause
42− , renderConflictClause
43 -- * Update
39 -- * Update
44 , update
40 , update
45 , update_
41 , update_
46 -- * Delete
42 -- * Delete
47 , deleteFrom
43 , deleteFrom
48 , deleteFrom_
44 , deleteFrom_
49− -- * With
45+ -- * Clauses
50− , with
46+ , Optional (..)
47+ , QueryClause (..)
48+ , pattern Values_
49+ , ReturningClause (..)
50+ , pattern Returning_
51+ , ConflictClause (..)
52+ , ConflictTarget (..)
53+ , ConflictAction (..)
54+ , UsingClause (..)
51 ) where
55 ) where
52
56
53import Control.DeepSeq
57import Control.DeepSeq
54import Data.ByteString hiding (foldr)
58import Data.ByteString hiding (foldr)
55−import Data.Monoid
59+import Data.Kind (Type)
56
60
57−import qualified Data.ByteString as ByteString
58import qualified Generics.SOP as SOP
61import qualified Generics.SOP as SOP
59import qualified GHC.Generics as GHC
62import qualified GHC.Generics as GHC
60
63
64+import Squeal.PostgreSQL.Alias
61import Squeal.PostgreSQL.Expression
65import Squeal.PostgreSQL.Expression
66+import Squeal.PostgreSQL.Expression.Logic
67+import Squeal.PostgreSQL.List
68+import Squeal.PostgreSQL.PG
62import Squeal.PostgreSQL.Render
69import Squeal.PostgreSQL.Render
63import Squeal.PostgreSQL.Query
70import Squeal.PostgreSQL.Query
64import Squeal.PostgreSQL.Schema
71import Squeal.PostgreSQL.Schema
65
72
73+-- $setup
74+-- >>> import Squeal.PostgreSQL
75+-- >>> import Data.Int
76+-- >>> import Data.Time
77+
66{- |
78{- |
67A `Manipulation` is a statement which may modify data in the database,
79A `Manipulation` is a statement which may modify data in the database,
68−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.
69A `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.
70
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+
71simple insert:
125simple insert:
72
126
127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]
128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
73>>> :{
129>>> :{
74let
130let
75− manipulation :: Manipulation
131+ manipulation :: Manipulation_ (Public Schema) () ()
76− '[ "tab" ::: '[] :=>
77− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
78− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ]] '[] '[]
79 manipulation =
132 manipulation =
80− insertRow_ #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)
133+ insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))
81−in renderManipulation manipulation
134+in printSQL manipulation
82:}
135:}
83−"INSERT INTO tab (col1, col2) VALUES (2, DEFAULT);"
136+INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)
84
137
85parameterized insert:
138parameterized insert:
86
139
140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]
141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
87>>> :{
142>>> :{
88let
143let
89− manipulation :: Manipulation
144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()
90− '[ "tab" ::: '[] :=>
91− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
92− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ]]
93− '[ 'NotNull 'PGint4, 'NotNull 'PGint4 ] '[]
94 manipulation =
145 manipulation =
95− insertRow_ #tab
96− (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))
97−in renderManipulation manipulation
147+in printSQL manipulation
98:}
148:}
99−"INSERT INTO tab (col1, col2) VALUES (($1 :: int4), ($2 :: int4));"
149+INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))
100
150
101returning insert:
151returning insert:
102
152
103>>> :{
153>>> :{
104let
154let
105− manipulation :: Manipulation
155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)
106− '[ "tab" ::: '[] :=>
107− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
108− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ]] '[]
109− '["fromOnly" ::: 'NotNull 'PGint4]
110 manipulation =
156 manipulation =
111− insertRow #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)
157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))
112− OnConflictDoRaise (Returning (#col1 `As` #fromOnly :* Nil))
158+ OnConflictDoRaise (Returning (#col1 `as` #fromOnly))
113−in renderManipulation manipulation
159+in printSQL manipulation
114:}
160:}
115−"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"
116
162
117upsert:
163upsert:
118
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)]
119>>> :{
168>>> :{
120let
169let
121− manipulation :: Manipulation
170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()
122− '[ "tab" ::: '[] :=>
123− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
124− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ]]
125− '[] '[ "sum" ::: 'NotNull 'PGint4]
126 manipulation =
171 manipulation =
127− insertRows #tab
172+ insertInto #customers
128− (Set 2 `As` #col1 :* Set 4 `As` #col2 :* Nil)
173+ (Values_ (Set "John Smith" `as` #name :* Set "john@smith.com" `as` #email))
129− [Set 6 `As` #col1 :* Set 8 `As` #col2 :* Nil]
174+ (OnConflict (OnConstraint #uq)
130− (OnConflictDoUpdate
175+ (DoUpdate (Set (#excluded ! #email <> "; " <> #customers ! #email) `as` #email) []))
131− (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)
176+ (Returning_ Nil)
132− [#col1 .== #col2])
133− (Returning $ (#col1 + #col2) `As` #sum :* Nil)
134−in renderManipulation manipulation
177+in printSQL manipulation
135:}
178:}
136−"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"))
137
180
138query insert:
181query insert:
139
182
140>>> :{
183>>> :{
141let
184let
142− manipulation :: Manipulation
185+ manipulation :: Manipulation_ (Public Schema) () ()
143− '[ "tab" ::: '[] :=>
186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))
144− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
145− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4
146− ]
147− , "other_tab" ::: '[] :=>
148− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
149− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4
150− ]
151− ] '[] '[]
152− manipulation =
153− insertQuery_ #tab
154− (selectStar (from (table (#other_tab `As` #t))))
155−in renderManipulation manipulation
187+in printSQL manipulation
156:}
188:}
157−"INSERT INTO tab SELECT * FROM other_tab AS t;"
189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"
158
190
159update:
191update:
160
192
161>>> :{
193>>> :{
162let
194let
163− manipulation :: Manipulation
195+ manipulation :: Manipulation_ (Public Schema) () ()
164− '[ "tab" ::: '[] :=>
165− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
166− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ]] '[] '[]
167− manipulation =
168− update_ #tab (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)
196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)
169− (#col1 ./= #col2)
170−in renderManipulation manipulation
197+in printSQL manipulation
171:}
198:}
172−"UPDATE tab SET col1 = 2 WHERE (col1 <> col2);"
199+UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")
173
200
174delete:
201delete:
175
202
176>>> :{
203>>> :{
177let
204let
178− manipulation :: Manipulation
205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)
179− '[ "tab" ::: '[] :=>
180− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
181− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ]] '[]
182− '[ "col1" ::: 'NotNull 'PGint4
183− , "col2" ::: 'NotNull 'PGint4 ]
184− manipulation = deleteFrom #tab (#col1 .== #col2) ReturningStar
206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)
185−in renderManipulation manipulation
207+in printSQL manipulation
186:}
208:}
187−"DELETE FROM tab WHERE (col1 = col2) RETURNING *;"
209+DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *
210+
211+delete and using clause:
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"
188-}
245-}
189−newtype Manipulation
246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where
190− (schema :: TablesType)
247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)
191− (params :: [NullityType])
192− (columns :: RelationType)
193− = UnsafeManipulation { renderManipulation :: ByteString }
194− deriving (GHC.Generic,Show,Eq,Ord,NFData)
195
248
196-- | Convert a `Query` into a `Manipulation`.
249-- | Convert a `Query` into a `Manipulation`.
197queryStatement
250queryStatement
198− :: Query schema params columns
251+ :: Query '[] commons schemas params columns
252+ -- ^ `Query` to embed as a `Manipulation`
199− -> Manipulation schema params columns
253+ -> Manipulation commons schemas params columns
200−queryStatement q = UnsafeManipulation $ renderQuery q <> ";"
254+queryStatement q = UnsafeManipulation $ renderSQL q
201
255
202{-----------------------------------------
256{-----------------------------------------
203INSERT statements
257INSERT statements
204-----------------------------------------}
258-----------------------------------------}
205
259
206−-- | Insert multiple rows.
260+{- |
207−--
208−-- 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
209−-- 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
210−-- 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
211−-- 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.
212−-- 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.
213−insertRows
266+-}
214− :: ( SOP.SListI columns
267+insertInto
215− , SOP.SListI results
268+ :: ( Has sch schemas schema
216− , Has tab schema table
269+ , Has tab schema ('Table table)
217− , columns ~ TableToColumns table )
270+ , columns ~ TableToColumns table
218− => Alias tab -- ^ table to insert into
271+ , row0 ~ TableToRow table
219− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert
272+ , SOP.SListI columns
220− -> [NP (Aliased (ColumnValue '[] params)) columns] -- ^ more rows to insert
273+ , SOP.SListI row1 )
274+ => QualifiedAlias sch tab
275+ -- ^ table
276+ -> QueryClause commons schemas params columns
277+ -- ^ what to insert
221− -> ConflictClause columns params
278+ -> ConflictClause tab commons schemas params table
222− -- ^ what to do in case of constraint conflict
279+ -- ^ what to do in case of conflict
223− -> ReturningClause columns params results -- ^ results to return
280+ -> ReturningClause commons schemas params '[tab ::: row0] row1
281+ -- ^ what to return
224− -> Manipulation schema params results
282+ -> Manipulation commons schemas params row1
225−insertRows tab row rows conflict returning = UnsafeManipulation $
283+insertInto tab qry conflict ret = UnsafeManipulation $
226− "INSERT" <+> "INTO" <+> renderAlias tab
284+ "INSERT" <+> "INTO" <+> renderSQL tab
227− <+> parenthesized (renderCommaSeparated renderAliasPart row)
285+ <+> renderSQL qry
286+ <> renderSQL conflict
287+ <> renderSQL ret
288+
289+-- | Like `insertInto` but with `OnConflictDoRaise` and `no` `ReturningClause`.
290+insertInto_
291+ :: ( Has sch schemas schema
292+ , Has tab schema ('Table table)
293+ , columns ~ TableToColumns table
294+ , row ~ TableToRow table
295+ , SOP.SListI columns )
296+ => QualifiedAlias sch tab
297+ -- ^ table
298+ -> QueryClause commons schemas params columns
299+ -- ^ what to insert
300+ -> Manipulation commons schemas params '[]
301+insertInto_ tab qry =
302+ insertInto tab qry OnConflictDoRaise (Returning_ Nil)
303+
304+-- | A `QueryClause` describes what to `insertInto` a table.
305+data QueryClause commons schemas params columns where
306+ Values
307+ :: SOP.SListI columns
308+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns
309+ -- ^ row of values
310+ -> [NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns]
311+ -- ^ additional rows of values
312+ -> QueryClause commons schemas params columns
313+ Select
314+ :: SOP.SListI columns
315+ => NP (Aliased (Optional (Expression '[] commons grp schemas params from))) columns
316+ -- ^ row of values
317+ -> TableExpression '[] commons grp schemas params from
318+ -- ^ from a table expression
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)
228− <+> "VALUES"
330+ <+> "VALUES"
229− <+> commaSeparated
331+ <+> commaSeparated
230− ( parenthesized
332+ ( parenthesized
231− . renderCommaSeparated renderColumnValuePart <$> row:rows )
333+ . renderCommaSeparated renderValuePart <$> row0 : rows )
232− <> renderConflictClause conflict
334+ Select row0 tab ->
233− <> renderReturningClause returning
335+ parenthesized (renderCommaSeparatedMaybe renderSQLPartMaybe row0)
336+ <+> "SELECT"
337+ <+> renderCommaSeparatedMaybe renderValuePartMaybe row0
338+ <+> renderSQL tab
339+ Subquery qry -> renderQuery qry
234 where
340 where
235− renderAliasPart, renderColumnValuePart
341+ renderSQLPartMaybe, renderValuePartMaybe
236− :: Aliased (ColumnValue '[] params) ty -> ByteString
342+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column
237− renderAliasPart (_ `As` name) = renderAlias name
343+ -> Maybe ByteString
238− renderColumnValuePart (value `As` _) = case value of
344+ renderSQLPartMaybe = \case
345+ Default `As` _ -> Nothing
346+ Set _ `As` name -> Just $ renderSQL name
347+ renderValuePartMaybe = \case
239− Default -> "DEFAULT"
348+ Default `As` _ -> Nothing
240− Set expression -> renderExpression expression
349+ Set value `As` _ -> Just $ renderExpression value
241−
350+ renderSQLPart, renderValuePart
242−-- | Insert a single row.
351+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column
243−insertRow
352+ -> ByteString
244− :: ( SOP.SListI columns
353+ renderSQLPart (_ `As` name) = renderSQL name
245− , SOP.SListI results
354+ renderValuePart (value `As` _) = renderSQL value
246− , Has tab schema table
355+
247− , columns ~ TableToColumns table )
356+-- | `Values_` describes a single `NP` list of `Aliased` `Optional` `Expression`s
248− => Alias tab -- ^ table to insert into
357+-- whose `ColumnsType` must match the tables'.
249− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert
358+pattern Values_
250− -> ConflictClause columns params
359+ :: SOP.SListI columns
251− -- ^ what to do in case of constraint conflict
360+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns
252− -> ReturningClause columns params results -- ^ results to return
361+ -- ^ row of values
253− -> Manipulation schema params results
362+ -> QueryClause commons schemas params columns
254−insertRow tab row = insertRows tab row []
363+pattern Values_ vals = Values vals []
255−
364+
256−-- | Insert multiple rows returning `Nil` and raising an error on conflicts.
365+-- | `Optional` is either `Default` or a value, parameterized by an appropriate
257−insertRows_
366+-- `ColumnConstraint`.
258− :: ( SOP.SListI columns
367+data Optional expr ty where
259− , Has tab schema table
368+ -- | Use the `Default` value for a column.
260− , columns ~ TableToColumns table )
261− => Alias tab -- ^ table to insert into
262− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert
263− -> [NP (Aliased (ColumnValue '[] params)) columns] -- ^ more rows to insert
264− -> Manipulation schema params '[]
265−insertRows_ tab row rows =
266− insertRows tab row rows OnConflictDoRaise (Returning Nil)
267−
268−-- | Insert a single row returning `Nil` and raising an error on conflicts.
269−insertRow_
270− :: ( SOP.SListI columns
271− , Has tab schema table
272− , columns ~ TableToColumns table )
273− => Alias tab -- ^ table to insert into
274− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert
275− -> Manipulation schema params '[]
276−insertRow_ tab row = insertRow tab row OnConflictDoRaise (Returning Nil)
277−
278−-- | Insert a `Query`.
279−insertQuery
280− :: ( SOP.SListI columns
281− , SOP.SListI results
282− , Has tab schema table
283− , columns ~ TableToColumns table )
284− => Alias tab -- ^ table to insert into
285− -> Query schema params (ColumnsToRelation columns)
286− -> ConflictClause columns params
287− -- ^ what to do in case of constraint conflict
288− -> ReturningClause columns params results -- ^ results to return
289− -> Manipulation schema params results
290−insertQuery tab query conflict returning = UnsafeManipulation $
291− "INSERT" <+> "INTO" <+> renderAlias tab
292− <+> renderQuery query
293− <> renderConflictClause conflict
294− <> renderReturningClause returning
295−
296−-- | Insert a `Query` returning `Nil` and raising an error on conflicts.
297−insertQuery_
298− :: ( SOP.SListI columns
299− , Has tab schema table
300− , columns ~ TableToColumns table )
301− => Alias tab -- ^ table to insert into
302− -> Query schema params (ColumnsToRelation columns)
303− -> Manipulation schema params '[]
304−insertQuery_ tab query =
305− insertQuery tab query OnConflictDoRaise (Returning Nil)
306−
307−-- | `ColumnValue`s are values to insert or update in a row
308−-- `Same` updates with the same value.
309−-- `Default` inserts or updates with the @DEFAULT@ value
310−-- `Set` a value to be an `Expression`, relative to the given
311−-- row for an update, and closed for an insert.
312−data ColumnValue
313− (columns :: RelationType)
314− (params :: [NullityType])
315− (ty :: ColumnType)
316− where
317− Same :: ColumnValue (column ': columns) params ty
318− Default :: ColumnValue columns params ('Def :=> ty)
369+ Default :: Optional expr ('Def :=> ty)
319− Set
370+ -- | `Set` a value for a column.
320− :: (forall table. Expression '[table ::: columns] 'Ungrouped params ty)
371+ Set :: expr ty -> Optional expr (def :=> ty)
321− -> ColumnValue columns params (constraint :=> 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
322
377
323-- | A `ReturningClause` computes and return value(s) based
378-- | A `ReturningClause` computes and return value(s) based
324-- on each row actually inserted, updated or deleted. This is primarily
379-- on each row actually inserted, updated or deleted. This is primarily
@@ -326,71 +381,100 @@ data ColumnValue
326-- serial sequence number. However, any expression using the table's columns
381-- serial sequence number. However, any expression using the table's columns
327-- is allowed. Only rows that were successfully inserted or updated or
382-- is allowed. Only rows that were successfully inserted or updated or
328-- deleted will be returned. For example, if a row was locked
383-- deleted will be returned. For example, if a row was locked
329−-- but not updated because an `OnConflictDoUpdate` condition was not satisfied,
384+-- but not updated because an `OnConflict` `DoUpdate` condition was not satisfied,
330−-- the row will not be returned. `ReturningStar` will return all columns
385+-- the row will not be returned. `Returning` `Star` will return all columns
331−-- 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
332-- values are desired.
387-- values are desired.
333−data ReturningClause
388+newtype ReturningClause commons schemas params from row =
334− (columns :: ColumnsType)
389+ Returning (Selection '[] commons 'Ungrouped schemas params from row)
335− (params :: [NullityType])
390+
336− (results :: RelationType)
391+instance RenderSQL (ReturningClause commons schemas params from row) where
337− where
392+ renderSQL = \case
338− ReturningStar
393+ Returning (List Nil) -> ""
339− :: results ~ ColumnsToRelation columns
340− => ReturningClause columns params results
341− Returning
342− :: rel ~ ColumnsToRelation columns
343− => NP (Aliased (Expression '[table ::: rel] 'Ungrouped params)) results
344− -> ReturningClause columns params results
345−
346−-- | Render a `ReturningClause`.
347−renderReturningClause
348− :: SOP.SListI results
349− => ReturningClause params columns results
350− -> ByteString
351−renderReturningClause = \case
352− ReturningStar -> " RETURNING *;"
353− Returning 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 (columns :: ColumnsType) params where
409+data ConflictClause tab commons schemas params table where
363− OnConflictDoRaise :: ConflictClause columns params
410+ OnConflictDoRaise :: ConflictClause tab commons schemas params table
364− OnConflictDoNothing :: ConflictClause columns params
411+ OnConflict
365− OnConflictDoUpdate
412+ :: ConflictTarget constraints
366− :: NP (Aliased (ColumnValue (ColumnsToRelation columns) params)) columns
413+ -- ^ conflict target
367− -> [Condition '[table ::: ColumnsToRelation columns] 'Ungrouped params]
414+ -> ConflictAction tab commons schemas params columns
415+ -- ^ conflict action
368− -> ConflictClause 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 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 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
@@ -400,113 +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
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 (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 '[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 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 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
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 (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 '[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
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 '[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 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
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 '[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" ::: ProductsTable, "products_deleted" ::: ProductsTable] '[ 'NotNull 'PGdate] '[]
486−-- manipulation = with
487−-- (deleteFrom #products (#date .< param @1) ReturningStar `As` #deleted_rows :* Nil)
488−-- (insertQuery_ #products_deleted (selectStar (from (table (#deleted_rows `As` #t)))))
489−-- in renderManipulation 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 (Join (RelationsToTables 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− let
508− str = renderManipulation common
509− len = ByteString.length str
510− str' = ByteString.take (len - 1) str -- remove ';'
511− in
512− parenthesized str'
squeal-postgresql/src/Squeal/PostgreSQL/Migration.hs+350−220
@@ -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
@@ -29,250 +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" ::: 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 & notNull) `As` #name :* Nil )
46+ notNullable text `as` #name )
41− ( primaryKey (Column #id :* Nil) `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" ::: UsersTable]
54+ makeEmails :: Migration Definition '["public" ::: '["users" ::: 'Table UsersTable]]
49− '["users" ::: UsersTable, "emails" ::: 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 & notNull) `As` #user_id :*
60+ notNullable int `as` #user_id :*
56− text `As` #email :* Nil )
61+ nullable text `as` #email )
57− ( primaryKey (Column #id :* Nil) `As` #pk_emails :*
62+ ( primaryKey #id `as` #pk_emails :*
58− foreignKey (Column #user_id :* Nil) #users (Column #id :* Nil)
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 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− ScopedTypeVariables
94− , OverloadedStrings
95− , DataKinds
125+ DataKinds
126+ , DeriveGeneric
127+ , FlexibleContexts
128+ , FlexibleInstances
96 , GADTs
129 , GADTs
97 , LambdaCase
130 , LambdaCase
98− , PolyKinds
99 , OverloadedLabels
131 , OverloadedLabels
132+ , OverloadedStrings
133+ , PolyKinds
134+ , QuantifiedConstraints
135+ , RankNTypes
100 , TypeApplications
136 , TypeApplications
101− , FlexibleContexts
102 , TypeOperators
137 , TypeOperators
103#-}
138#-}
104
139
105module Squeal.PostgreSQL.Migration
140module Squeal.PostgreSQL.Migration
106 ( -- * Migration
141 ( -- * Migration
107 Migration (..)
142 Migration (..)
108− , migrateUp
143+ , Migratory (..)
109− , migrateDown
144+ , Terminally (..)
110− -- * Aligned lists
145+ , terminally
111− , AlignedList (..)
146+ , pureMigration
112− , single
113− -- * Migration table
114 , MigrationsTable
147 , MigrationsTable
115− , createMigrations
148+ , defaultMain
116− , insertMigration
117− , deleteMigration
118− , selectMigration
119 ) where
149 ) where
120
150
121import Control.Category
151import Control.Category
122import Control.Monad
152import Control.Monad
123−import Control.Monad.Base
153+import Data.ByteString (ByteString)
124−import Control.Monad.Trans.Control
125−import Data.Monoid
154+import Data.Foldable (traverse_)
126−import Generics.SOP (K(..))
127import Data.Function ((&))
155import Data.Function ((&))
156+import Data.List ((\\))
128import Data.Text (Text)
157import Data.Text (Text)
158+import Data.Time (UTCTime)
129−import Prelude hiding (id, (.))
159+import Prelude hiding ((.), id)
160+import System.Environment
161+import UnliftIO (MonadIO (..))
130
162
131−import Squeal.PostgreSQL
163+import qualified Data.Text.IO as Text (putStrLn)
164+import qualified Generics.SOP as SOP
165+import qualified GHC.Generics as GHC
132
166
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
182+
183+-- | A `Migration` is a named "isomorphism" over a given category.
133−-- | A `Migration` should contain an inverse pair of
184+-- It should contain an inverse pair of `up` and `down`
134−-- `up` and `down` instructions and a unique `name`.
185+-- instructions and a unique `name`.
135−data Migration io schema0 schema1 = Migration
186+data Migration p schemas0 schemas1 = Migration
136 { name :: Text -- ^ The `name` of a `Migration`.
187 { name :: Text -- ^ The `name` of a `Migration`.
137 -- Each `name` in a `Migration` should be unique.
188 -- Each `name` in a `Migration` should be unique.
138− , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.
189+ , up :: p schemas0 schemas1 -- ^ The `up` instruction of a `Migration`.
139− , 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
140 }
260 }
141
261
142−-- | An `AlignedList` is a type-aligned list or free category.
262+instance Migratory (Terminally PQ IO) where
143−data AlignedList p x0 x1 where
144− Done :: AlignedList p x x
145− (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2
146−infixr 7 :>>
147−instance Category (AlignedList p) where
148− id = Done
149− (.) list = \case
150− Done -> list
151− step :>> steps -> step :>> (steps >>> list)
152−
153−-- | A `single` step.
154−single :: p x0 x1 -> AlignedList p x0 x1
155−single step = step :>> Done
156−
157−-- | Run `Migration`s by creating the `MigrationsTable`
158−-- if it does not exist and then in a transaction, for each each `Migration`
159−-- query to see if the `Migration` is executed. If not, then
160−-- execute the `Migration` and insert its row in the `MigrationsTable`.
161−migrateUp
162− :: MonadBaseControl IO io
163− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run
164− -> PQ
165− ("schema_migrations" ::: MigrationsTable ': schema0)
166− ("schema_migrations" ::: MigrationsTable ': schema1)
167− io ()
168−migrateUp migration =
169− define createMigrations
170− & pqBind okResult
171− & pqThen (transactionallySchema_ (upMigrations migration))
172− where
173
263
174− upMigrations
264+ migrateUp migration = unsafePQ . transactionally_ $ do
175− :: MonadBaseControl IO io
265+ define createMigrations
176− => AlignedList (Migration io) schema0 schema1
266+ upMigrations migration
177− -> PQ
267+
178− ("schema_migrations" ::: MigrationsTable ': schema0)
268+ where
179− ("schema_migrations" ::: MigrationsTable ': schema1)
269+
180− io ()
270+ upMigrations
271+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1
272+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
181− upMigrations = \case
273+ upMigrations = \case
182− Done -> return ()
274+ Done -> return ()
183− step :>> steps -> upMigration step & pqThen (upMigrations steps)
275+ step :>> steps -> upMigration step >> upMigrations steps
184−
276+
185− upMigration
277+ upMigration
186− :: MonadBase IO io
278+ :: Migration (Terminally PQ IO) schemas0 schemas1
187− => Migration io schema0 schema1 -> PQ
279+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
188− ("schema_migrations" ::: MigrationsTable ': schema0)
189− ("schema_migrations" ::: MigrationsTable ': schema1)
190− io ()
191− upMigration step =
280+ upMigration step = do
192− queryExecuted step
281+ executed <- queryExecuted step
193− & pqBind (\ executed ->
282+ unless (executed == 1) $ do
194− if executed == 1 -- up step has already been executed
283+ unsafePQ . runTerminally $ up step
195− then PQ (\ _ -> return (K ())) -- unsafely switch schemas
196− else
197− pqEmbed (up step) -- safely switch schemas
198− & pqThen (manipulateParams insertMigration (Only (name step)))
284+ manipulateParams_ insertMigration (Only (name step))
199− -- insert execution record
285+
200− & pqBind okResult)
201−
202− queryExecuted
286+ queryExecuted
203− :: MonadBase IO io
287+ :: Migration (Terminally PQ IO) schemas0 schemas1
204− => Migration io schema0 schema1 -> PQ
288+ -> PQ MigrationsSchemas MigrationsSchemas IO Row
205− ("schema_migrations" ::: MigrationsTable ': schema0)
206− ("schema_migrations" ::: MigrationsTable ': schema0)
207− io Row
208− queryExecuted step = do
289+ queryExecuted step = do
209− result <- runQueryParams selectMigration (Only (name step))
290+ result <- runQueryParams selectMigration (Only (name step))
210− okResult result
211− ntuples result
291+ ntuples result
212−
292+
213−-- | Rewind `Migration`s by creating the `MigrationsTable`
293+ migrateDown migrations = unsafePQ . transactionally_ $ do
214−-- if it does not exist and then in a transaction, for each each `Migration`
215−-- query to see if the `Migration` is executed. If it is, then
216−-- rewind the `Migration` and delete its row in the `MigrationsTable`.
217−migrateDown
218− :: MonadBaseControl IO io
219− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind
220− -> PQ
221− ("schema_migrations" ::: MigrationsTable ': schema1)
222− ("schema_migrations" ::: MigrationsTable ': schema0)
223− io ()
224−migrateDown migrations =
225− define createMigrations
294+ define createMigrations
226− & pqBind okResult
227− & pqThen (transactionallySchema_ (downMigrations migrations))
295+ downMigrations migrations
296+
228− where
297+ where
229
298
230− downMigrations
299+ downMigrations
231− :: MonadBaseControl IO io
300+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1
232− => AlignedList (Migration io) schema0 schema1 -> PQ
301+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
233− ("schema_migrations" ::: MigrationsTable ': schema1)
234− ("schema_migrations" ::: MigrationsTable ': schema0)
235− io ()
236− downMigrations = \case
302+ downMigrations = \case
237− Done -> return ()
303+ Done -> return ()
238− step :>> steps -> downMigrations steps & pqThen (downMigration step)
304+ step :>> steps -> downMigrations steps >> downMigration step
239−
305+
240− downMigration
306+ downMigration
241− :: MonadBase IO io
307+ :: Migration (Terminally PQ IO) schemas0 schemas1
242− => Migration io schema0 schema1 -> PQ
308+ -> PQ MigrationsSchemas MigrationsSchemas IO ()
243− ("schema_migrations" ::: MigrationsTable ': schema1)
244− ("schema_migrations" ::: MigrationsTable ': schema0)
245− io ()
246− downMigration step =
309+ downMigration step = do
247− queryExecuted step
310+ executed <- queryExecuted step
248− & pqBind (\ executed ->
311+ unless (executed == 0) $ do
249− if executed == 0 -- up step has not been executed
312+ unsafePQ . runTerminally $ down step
250− then PQ (\ _ -> return (K ())) -- unsafely switch schemas
251− else
252− pqEmbed (down step) -- safely switch schemas
253− & pqThen (manipulateParams deleteMigration (Only (name step)))
313+ manipulateParams_ deleteMigration (Only (name step))
254− -- delete execution record
314+
255− & pqBind okResult)
256−
257− queryExecuted
315+ queryExecuted
258− :: MonadBase IO io
316+ :: Migration (Terminally PQ IO) schemas0 schemas1
259− => Migration io schema0 schema1 -> PQ
317+ -> PQ MigrationsSchemas MigrationsSchemas IO Row
260− ("schema_migrations" ::: MigrationsTable ': schema1)
261− ("schema_migrations" ::: MigrationsTable ': schema1)
262− io Row
263− queryExecuted step = do
318+ queryExecuted step = do
264− result <- runQueryParams selectMigration (Only (name step))
319+ result <- runQueryParams selectMigration (Only (name step))
265− okResult result
266− ntuples result
320+ ntuples result
267−
321+
268−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
269−okResult result = do
323+unsafePQ (PQ pq) = PQ $ fmap (SOP.K . SOP.unK) . pq . SOP.K . SOP.unK
270− status <- resultStatus result
271− when (not (status `elem` [CommandOk, TuplesOk])) $ do
272− errorMessageMaybe <- resultErrorMessage result
273− case errorMessageMaybe of
274− Nothing -> error "migrateDown: unknown error"
275− Just msg -> error ("migrationDown: " <> show msg)
276
324
277-- | The `TableType` for a Squeal migration.
325-- | The `TableType` for a Squeal migration.
278type MigrationsTable =
326type MigrationsTable =
@@ -281,38 +329,120 @@ type MigrationsTable =
281 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz
329 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz
282 ]
330 ]
283
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+
284-- | Creates a `MigrationsTable` if it does not already exist.
343-- | Creates a `MigrationsTable` if it does not already exist.
285−createMigrations
344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas
286− :: Has "schema_migrations" schema MigrationsTable
287− => Definition schema schema
288createMigrations =
345createMigrations =
289 createTableIfNotExists #schema_migrations
346 createTableIfNotExists #schema_migrations
290− ( (text & notNull) `As` #name :*
347+ ( (text & notNullable) `as` #name :*
291− (timestampWithTimeZone & notNull & default_ currentTimestamp)
348+ (timestampWithTimeZone & notNullable & default_ currentTimestamp)
292− `As` #executed_at :* Nil )
349+ `as` #executed_at )
293− ( unique (Column #name :* Nil) `As` #migrations_unique_name :* Nil )
350+ ( unique #name `as` #migrations_unique_name )
294−
351+
295−-- | Inserts a `Migration` into the `MigrationsTable`
352+-- | Inserts a `Migration` into the `MigrationsTable`, returning
296−insertMigration
353+-- the time at which it was inserted.
297− :: Has "schema_migrations" schema MigrationsTable
354+insertMigration :: Manipulation_ MigrationsSchemas (Only Text) ()
298− => Manipulation schema '[ 'NotNull 'PGtext] '[]
299−insertMigration = insertRow_ #schema_migrations
355+insertMigration = insertInto_ #schema_migrations
300− ( Set (param @1) `As` #name :*
301− Default `As` #executed_at :* Nil )
356+ (Values_ (Set (param @1) `as` #name :* Default `as` #executed_at))
302−
357+
303−-- | Deletes a `Migration` from the `MigrationsTable`
358+-- | Deletes a `Migration` from the `MigrationsTable`, returning
359+-- the time at which it was inserted.
304−deleteMigration
360+deleteMigration :: Manipulation_ MigrationsSchemas (Only Text) ()
305− :: Has "schema_migrations" schema MigrationsTable
306− => Manipulation schema '[ 'NotNull 'PGtext ] '[]
307deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)
361deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)
308
362
309-- | Selects a `Migration` from the `MigrationsTable`, returning
363-- | Selects a `Migration` from the `MigrationsTable`, returning
310−-- the time at which it was executed.
364+-- the time at which it was inserted.
311selectMigration
365selectMigration
312− :: Has "schema_migrations" schema MigrationsTable
366+ :: Query_ MigrationsSchemas (Only Text) (Only UTCTime)
313− => Query schema '[ 'NotNull 'PGtext ]
314− '[ "executed_at" ::: 'NotNull 'PGtimestamptz ]
315−selectMigration = select
367+selectMigration = select_ (#executed_at `as` #fromOnly)
316− (#executed_at `As` #executed_at :* Nil)
317− ( from (table (#schema_migrations `As` #m))
368+ $ from (table (#schema_migrations))
318− & 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+319−216
@@ -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`
@@ -20,15 +20,11 @@ of executing Squeal commands.
20
20
21{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
21{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
22{-# LANGUAGE
22{-# LANGUAGE
23− DataKinds
24− , DefaultSignatures
23+ DefaultSignatures
25 , FunctionalDependencies
24 , FunctionalDependencies
26− , PolyKinds
27− , DeriveFunctor
28 , FlexibleContexts
25 , FlexibleContexts
29 , FlexibleInstances
26 , FlexibleInstances
30− , MagicHash
27+ , InstanceSigs
31− , MultiParamTypeClasses
32 , OverloadedStrings
28 , OverloadedStrings
33 , RankNTypes
29 , RankNTypes
34 , ScopedTypeVariables
30 , ScopedTypeVariables
@@ -53,9 +49,7 @@ module Squeal.PostgreSQL.PQ
53 , evalPQ
49 , evalPQ
54 , IndexedMonadTransPQ (..)
50 , IndexedMonadTransPQ (..)
55 , MonadPQ (..)
51 , MonadPQ (..)
56− , PQRun
52+ -- * Results
57− , pqliftWith
58− -- * Result
59 , LibPQ.Result
53 , LibPQ.Result
60 , LibPQ.Row
54 , LibPQ.Row
61 , ntuples
55 , ntuples
@@ -67,22 +61,33 @@ module Squeal.PostgreSQL.PQ
67 , LibPQ.ExecStatus (..)
61 , LibPQ.ExecStatus (..)
68 , resultStatus
62 , resultStatus
69 , resultErrorMessage
63 , resultErrorMessage
64+ , resultErrorCode
65+ -- * Exceptions
66+ , SquealException (..)
67+ , PQState (..)
68+ , okResult
69+ , catchSqueal
70+ , handleSqueal
71+ , trySqueal
70 ) where
72 ) where
71
73
72−import Control.Exception.Lifted
74+import Control.Exception (Exception, throw)
73−import Control.Monad.Base
74import Control.Monad.Except
75import Control.Monad.Except
75import Control.Monad.Morph
76import Control.Monad.Morph
76−import Control.Monad.Trans.Control
77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)
77import Data.ByteString (ByteString)
78import Data.ByteString (ByteString)
78import Data.Foldable
79import Data.Foldable
79import Data.Function ((&))
80import Data.Function ((&))
81+import Data.Functor ((<&>))
80import Data.Kind
82import Data.Kind
81−import Data.Monoid
83+import Data.Text (pack, Text)
82import Data.Traversable
84import Data.Traversable
83import Generics.SOP
85import Generics.SOP
86+import PostgreSQL.Binary.Encoding (encodingBytes)
84
87
88+import qualified Control.Monad.Fail as Fail
85import qualified Database.PostgreSQL.LibPQ as LibPQ
89import qualified Database.PostgreSQL.LibPQ as LibPQ
90+import qualified PostgreSQL.Binary.Encoding as Encoding
86
91
87import Squeal.PostgreSQL.Binary
92import Squeal.PostgreSQL.Binary
88import Squeal.PostgreSQL.Definition
93import Squeal.PostgreSQL.Definition
@@ -95,7 +100,6 @@ import Control.Monad.Trans.Identity
95import Control.Monad.Trans.Reader
100import Control.Monad.Trans.Reader
96import Control.Monad.Trans.Maybe
101import Control.Monad.Trans.Maybe
97import Control.Monad.Trans.Cont
102import Control.Monad.Trans.Cont
98−import Control.Monad.Trans.List
99
103
100import qualified Control.Monad.Trans.State.Lazy as Lazy
104import qualified Control.Monad.Trans.State.Lazy as Lazy
101import qualified Control.Monad.Trans.State.Strict as Strict
105import qualified Control.Monad.Trans.State.Strict as Strict
@@ -104,6 +108,9 @@ import qualified Control.Monad.Trans.Writer.Strict as Strict
104import qualified Control.Monad.Trans.RWS.Lazy as Lazy
108import qualified Control.Monad.Trans.RWS.Lazy as Lazy
105import qualified Control.Monad.Trans.RWS.Strict as Strict
109import qualified Control.Monad.Trans.RWS.Strict as Strict
106
110
111+-- $setup
112+-- >>> import Squeal.PostgreSQL
113+
107{- | Makes a new connection to the database server.
114{- | Makes a new connection to the database server.
108
115
109This function opens a new database connection using the parameters taken
116This function opens a new database connection using the parameters taken
@@ -130,22 +137,22 @@ Note that, for now, squeal doesn't offer any protection from connecting
130with the wrong schema!
137with the wrong schema!
131-}
138-}
132connectdb
139connectdb
133− :: forall schema io
140+ :: forall schemas io
134− . MonadBase IO io
141+ . MonadIO io
135 => ByteString -- ^ conninfo
142 => ByteString -- ^ conninfo
136− -> io (K LibPQ.Connection schema)
143+ -> io (K LibPQ.Connection schemas)
137−connectdb = fmap K . liftBase . LibPQ.connectdb
144+connectdb = fmap K . liftIO . LibPQ.connectdb
138
145
139-- | Closes the connection to the server.
146-- | Closes the connection to the server.
140−finish :: MonadBase IO io => K LibPQ.Connection schema -> io ()
147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()
141−finish = liftBase . LibPQ.finish . unK
148+finish = liftIO . LibPQ.finish . unK
142
149
143-- | Do `connectdb` and `finish` before and after a computation.
150-- | Do `connectdb` and `finish` before and after a computation.
144withConnection
151withConnection
145− :: forall schema0 schema1 io x
152+ :: forall schemas0 schemas1 io x
146− . MonadBaseControl IO io
153+ . MonadUnliftIO io
147 => ByteString
154 => ByteString
148− -> PQ schema0 schema1 io x
155+ -> PQ schemas0 schemas1 io x
149 -> io x
156 -> io x
150withConnection connString action = do
157withConnection connString action = do
151 K x <- bracket (connectdb connString) finish (unPQ action)
158 K x <- bracket (connectdb connString) finish (unPQ action)
@@ -153,47 +160,47 @@ withConnection connString action = do
153
160
154-- | Safely `lowerConnection` to a smaller schema.
161-- | Safely `lowerConnection` to a smaller schema.
155lowerConnection
162lowerConnection
156− :: K LibPQ.Connection (table ': schema)
163+ :: K LibPQ.Connection (schema ': schemas)
157− -> K LibPQ.Connection schema
164+ -> K LibPQ.Connection schemas
158lowerConnection (K conn) = K conn
165lowerConnection (K conn) = K conn
159
166
160-- | 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,
161-- `PQ`.
168-- `PQ`.
162newtype PQ
169newtype PQ
163− (schema0 :: TablesType)
170+ (schemas0 :: SchemasType)
164− (schema1 :: TablesType)
171+ (schemas1 :: SchemasType)
165 (m :: Type -> Type)
172 (m :: Type -> Type)
166 (x :: Type) =
173 (x :: Type) =
167− PQ { unPQ :: K LibPQ.Connection schema0 -> m (K x schema1) }
174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }
168
175
169−instance Monad m => Functor (PQ schema0 schema1 m) where
176+instance Monad m => Functor (PQ schemas0 schemas1 m) where
170 fmap f (PQ pq) = PQ $ \ conn -> do
177 fmap f (PQ pq) = PQ $ \ conn -> do
171 K x <- pq conn
178 K x <- pq conn
172 return $ K (f x)
179 return $ K (f x)
173
180
174−-- | Run a `PQ` and keep the result and the `Connection`.
181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.
175runPQ
182runPQ
176 :: Functor m
183 :: Functor m
177− => PQ schema0 schema1 m x
184+ => PQ schemas0 schemas1 m x
178− -> K LibPQ.Connection schema0
185+ -> K LibPQ.Connection schemas0
179− -> m (x, K LibPQ.Connection schema1)
186+ -> m (x, K LibPQ.Connection schemas1)
180runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn
187runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn
181 -- K x <- pq conn
188 -- K x <- pq conn
182 -- return (x, K (unK conn))
189 -- return (x, K (unK conn))
183
190
184−-- | Execute a `PQ` and discard the result but keep the `Connection`.
191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.
185execPQ
192execPQ
186 :: Functor m
193 :: Functor m
187− => PQ schema0 schema1 m x
194+ => PQ schemas0 schemas1 m x
188− -> K LibPQ.Connection schema0
195+ -> K LibPQ.Connection schemas0
189− -> m (K LibPQ.Connection schema1)
196+ -> m (K LibPQ.Connection schemas1)
190execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn
197execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn
191
198
192−-- | Evaluate a `PQ` and discard the `Connection` but keep the result.
199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.
193evalPQ
200evalPQ
194 :: Functor m
201 :: Functor m
195− => PQ schema0 schema1 m x
202+ => PQ schemas0 schemas1 m x
196− -> K LibPQ.Connection schema0
203+ -> K LibPQ.Connection schemas0
197 -> m x
204 -> m x
198evalPQ (PQ pq) conn = unK <$> pq conn
205evalPQ (PQ pq) conn = unK <$> pq conn
199
206
@@ -201,50 +208,56 @@ evalPQ (PQ pq) conn = unK <$> pq conn
201-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).
208-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).
202-- An indexed monad transformer transforms a `Monad` into an indexed monad.
209-- An indexed monad transformer transforms a `Monad` into an indexed monad.
203-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that
210-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that
204−-- support running `Definition`s using `define` and embedding a computation
211+-- support running `Definition`s using `define`.
205−-- in a larger schema using `pqEmbed`.
206class IndexedMonadTransPQ pq where
212class IndexedMonadTransPQ pq where
207
213
208 -- | indexed analog of `<*>`
214 -- | indexed analog of `<*>`
209 pqAp
215 pqAp
210 :: Monad m
216 :: Monad m
211− => pq schema0 schema1 m (x -> y)
217+ => pq schemas0 schemas1 m (x -> y)
212− -> pq schema1 schema2 m x
218+ -> pq schemas1 schemas2 m x
213− -> pq schema0 schema2 m y
219+ -> pq schemas0 schemas2 m y
214
220
215 -- | indexed analog of `join`
221 -- | indexed analog of `join`
216 pqJoin
222 pqJoin
217 :: Monad m
223 :: Monad m
218− => pq schema0 schema1 m (pq schema1 schema2 m y)
224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)
219− -> pq schema0 schema2 m y
225+ -> pq schemas0 schemas2 m y
226+ pqJoin pq = pq & pqBind id
220
227
221 -- | indexed analog of `=<<`
228 -- | indexed analog of `=<<`
222 pqBind
229 pqBind
223 :: Monad m
230 :: Monad m
224− => (x -> pq schema1 schema2 m y)
231+ => (x -> pq schemas1 schemas2 m y)
225− -> pq schema0 schema1 m x
232+ -> pq schemas0 schemas1 m x
226− -> pq schema0 schema2 m y
233+ -> pq schemas0 schemas2 m y
227
234
228 -- | indexed analog of flipped `>>`
235 -- | indexed analog of flipped `>>`
229 pqThen
236 pqThen
230 :: Monad m
237 :: Monad m
231− => pq schema1 schema2 m y
238+ => pq schemas1 schemas2 m y
232− -> pq schema0 schema1 m x
239+ -> pq schemas0 schemas1 m x
233− -> pq schema0 schema2 m y
240+ -> pq schemas0 schemas2 m y
241+ pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)
234
242
235− -- | Safely embed a computation in a larger schema.
243+ -- | indexed analog of `<=<`
236− pqEmbed
244+ pqAndThen
237 :: Monad m
245 :: Monad m
238− => pq schema0 schema1 m x
246+ => (y -> pq schemas1 schemas2 m z)
239− -> pq (table ': schema0) (table : schema1) m x
247+ -> (x -> pq schemas0 schemas1 m y)
248+ -> x -> pq schemas0 schemas2 m z
249+ pqAndThen g f x = pqBind g (f x)
240
250
241− -- | Run a `Definition` with `LibPQ.exec`, we expect that libpq obeys the law
251+ -- | Run a `Definition` with `LibPQ.exec`.
242 --
252 --
253+ -- It should be functorial in effect.
254+ --
255+ -- @define id = return ()@
243− -- @define statement1 & pqThen (define statement2) = define (statement1 >>> statement2)@
256+ -- @define (statement1 >>> statement2) = define statement1 & pqThen (define statement2)@
244 define
257 define
245− :: MonadBase IO io
258+ :: MonadIO io
246− => Definition schema0 schema1
259+ => Definition schemas0 schemas1
247− -> pq schema0 schema1 io (K LibPQ.Result '[])
260+ -> pq schemas0 schemas1 io ()
248
261
249instance IndexedMonadTransPQ PQ where
262instance IndexedMonadTransPQ PQ where
250
263
@@ -253,34 +266,30 @@ instance IndexedMonadTransPQ PQ where
253 K x' <- x (K (unK conn))
266 K x' <- x (K (unK conn))
254 return $ K (f' x')
267 return $ K (f' x')
255
268
256− pqJoin pq = pq & pqBind id
257−
258 pqBind f (PQ x) = PQ $ \ conn -> do
269 pqBind f (PQ x) = PQ $ \ conn -> do
259 K x' <- x conn
270 K x' <- x conn
260 unPQ (f x') (K (unK conn))
271 unPQ (f x') (K (unK conn))
261
272
262− pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)
263−
264− pqEmbed (PQ pq) = PQ $ \ (K conn) -> do
265− K x <- pq (K conn)
266− return $ K x
267−
268 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do
273 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do
269− resultMaybe <- liftBase $ LibPQ.exec conn q
274+ resultMaybe <- liftIO $ LibPQ.exec conn q
270 case resultMaybe of
275 case resultMaybe of
271− Nothing -> error
276+ Nothing -> throw $ ResultException
272 "define: LibPQ.exec returned no results"
277 "define: LibPQ.exec returned no results"
273− Just result -> return $ K (K result)
278+ Just result -> K <$> okResult_ result
274
279
275−{- | `MonadPQ` is an `mtl` style constraint, similar to
280+{- | `MonadPQ` is an @mtl@ style constraint, similar to
276−`Control.Monad.State.Class.MonadState`, for using `LibPQ` to
281+`Control.Monad.State.Class.MonadState`, for using `Database.PostgreSQL.LibPQ` to
277
282
278* `manipulateParams` runs a `Manipulation` with params from a type
283* `manipulateParams` runs a `Manipulation` with params from a type
279 with a `ToParams` constraint. It calls `LibPQ.execParams` and
284 with a `ToParams` constraint. It calls `LibPQ.execParams` and
280 doesn't afraid of anything.
285 doesn't afraid of anything.
281
286
287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.
288+
282* `manipulate` is like `manipulateParams` for a parameter-free statement.
289* `manipulate` is like `manipulateParams` for a parameter-free statement.
283
290
291+* `manipulate_` is like `manipulate` for a returning-free statement.
292+
284* `runQueryParams` is like `manipulateParams` for query statements.
293* `runQueryParams` is like `manipulateParams` for query statements.
285
294
286* `runQuery` is like `runQueryParams` for a parameter-free statement.
295* `runQuery` is like `runQueryParams` for a parameter-free statement.
@@ -294,11 +303,11 @@ instance IndexedMonadTransPQ PQ where
294* `forPrepared` is a flipped `traversePrepared`
303* `forPrepared` is a flipped `traversePrepared`
295
304
296* `traversePrepared_` is like `traversePrepared` but works on `Foldable`
305* `traversePrepared_` is like `traversePrepared` but works on `Foldable`
297− containers and returns unit.
306+ containers for a returning-free statement.
298
307
299* `forPrepared_` is a flipped `traversePrepared_`.
308* `forPrepared_` is a flipped `traversePrepared_`.
300
309
301−* `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
302 into your monad.
311 into your monad.
303
312
304To define an instance, you can minimally define only `manipulateParams`,
313To define an instance, you can minimally define only `manipulateParams`,
@@ -306,304 +315,398 @@ To define an instance, you can minimally define only `manipulateParams`,
306a default instance.
315a default instance.
307
316
308-}
317-}
309−class Monad pq => MonadPQ schema pq | pq -> schema where
318+class Monad pq => MonadPQ schemas pq | pq -> schemas where
310 manipulateParams
319 manipulateParams
311− :: ToParams x params
320+ :: (ToParams x params, All OidOfParam params)
312− => Manipulation schema params ys
321+ => Manipulation '[] schemas params ys
313− -- ^ `insertRows`, `update` or `deleteFrom`
322+ -- ^ `insertInto`, `update` or `deleteFrom`
314 -> x -> pq (K LibPQ.Result ys)
323 -> x -> pq (K LibPQ.Result ys)
315 default manipulateParams
324 default manipulateParams
316− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
325+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
317− => ToParams x params
326+ => (ToParams x params, All OidOfParam params)
318− => Manipulation schema params ys
327+ => Manipulation '[] schemas params ys
319− -- ^ `insertRows`, `update` or `deleteFrom`
328+ -- ^ `insertInto`, `update` or `deleteFrom`
320 -> x -> pq (K LibPQ.Result ys)
329 -> x -> pq (K LibPQ.Result ys)
321 manipulateParams manipulation params = lift $
330 manipulateParams manipulation params = lift $
322 manipulateParams manipulation params
331 manipulateParams manipulation params
323
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+
324− manipulate :: Manipulation schema '[] ys -> pq (K LibPQ.Result ys)
340+ manipulate :: Manipulation '[] schemas '[] ys -> pq (K LibPQ.Result ys)
325 manipulate statement = manipulateParams statement ()
341 manipulate statement = manipulateParams statement ()
326
342
343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()
344+ manipulate_ = void . manipulate
345+
327 runQueryParams
346 runQueryParams
328− :: ToParams x params
347+ :: (ToParams x params, All OidOfParam params)
329− => Query schema params ys
348+ => Query '[] '[] schemas params ys
330 -- ^ `select` and friends
349 -- ^ `select` and friends
331 -> x -> pq (K LibPQ.Result ys)
350 -> x -> pq (K LibPQ.Result ys)
332 runQueryParams = manipulateParams . queryStatement
351 runQueryParams = manipulateParams . queryStatement
333
352
334 runQuery
353 runQuery
335− :: Query schema '[] ys
354+ :: Query '[] '[] schemas '[] ys
336 -- ^ `select` and friends
355 -- ^ `select` and friends
337 -> pq (K LibPQ.Result ys)
356 -> pq (K LibPQ.Result ys)
338 runQuery q = runQueryParams q ()
357 runQuery q = runQueryParams q ()
339
358
340 traversePrepared
359 traversePrepared
341− :: (ToParams x params, Traversable list)
360+ :: (ToParams x params, Traversable list, All OidOfParam params)
342− => Manipulation schema params ys
361+ => Manipulation '[] schemas params ys
343− -- ^ `insertRows`, `update`, or `deleteFrom`, and friends
362+ -- ^ `insertInto`, `update`, or `deleteFrom`, and friends
344 -> list x -> pq (list (K LibPQ.Result ys))
363 -> list x -> pq (list (K LibPQ.Result ys))
345 default traversePrepared
364 default traversePrepared
346− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
365+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
347− => (ToParams x params, Traversable list)
366+ => (ToParams x params, Traversable list, All OidOfParam params)
348− => 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))
349 traversePrepared manipulation params = lift $
368 traversePrepared manipulation params = lift $
350 traversePrepared manipulation params
369 traversePrepared manipulation params
351
370
352 forPrepared
371 forPrepared
353− :: (ToParams x params, Traversable list)
372+ :: (ToParams x params, Traversable list, All OidOfParam params)
354 => list x
373 => list x
355− -> Manipulation schema params ys
374+ -> Manipulation '[] schemas params ys
356− -- ^ `insertRows`, `update` or `deleteFrom`
375+ -- ^ `insertInto`, `update` or `deleteFrom`
357 -> pq (list (K LibPQ.Result ys))
376 -> pq (list (K LibPQ.Result ys))
358 forPrepared = flip traversePrepared
377 forPrepared = flip traversePrepared
359
378
360 traversePrepared_
379 traversePrepared_
361− :: (ToParams x params, Foldable list)
380+ :: (ToParams x params, Foldable list, All OidOfParam params)
362− => Manipulation schema params '[]
381+ => Manipulation '[] schemas params '[]
363− -- ^ `insertRows`, `update` or `deleteFrom`
382+ -- ^ `insertInto`, `update` or `deleteFrom`
364 -> list x -> pq ()
383 -> list x -> pq ()
365 default traversePrepared_
384 default traversePrepared_
366− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
385+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
367− => (ToParams x params, Foldable list)
386+ => (ToParams x params, Foldable list, All OidOfParam params)
368− => Manipulation schema params '[]
387+ => Manipulation '[] schemas params '[]
369− -- ^ `insertRows`, `update` or `deleteFrom`
388+ -- ^ `insertInto`, `update` or `deleteFrom`
370 -> list x -> pq ()
389 -> list x -> pq ()
371 traversePrepared_ manipulation params = lift $
390 traversePrepared_ manipulation params = lift $
372 traversePrepared_ manipulation params
391 traversePrepared_ manipulation params
373
392
374 forPrepared_
393 forPrepared_
375− :: (ToParams x params, Foldable list)
394+ :: (ToParams x params, Foldable list, All OidOfParam params)
376 => list x
395 => list x
377− -> Manipulation schema params '[]
396+ -> Manipulation '[] schemas params '[]
378− -- ^ `insertRows`, `update` or `deleteFrom`
397+ -- ^ `insertInto`, `update` or `deleteFrom`
379 -> pq ()
398 -> pq ()
380 forPrepared_ = flip traversePrepared_
399 forPrepared_ = flip traversePrepared_
381
400
382 liftPQ :: (LibPQ.Connection -> IO a) -> pq a
401 liftPQ :: (LibPQ.Connection -> IO a) -> pq a
383 default liftPQ
402 default liftPQ
384− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)
403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)
385 => (LibPQ.Connection -> IO a) -> pq a
404 => (LibPQ.Connection -> IO a) -> pq a
386 liftPQ = lift . liftPQ
405 liftPQ = lift . liftPQ
387
406
388−instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)
407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)
389− => MonadPQ schema (PQ schema0 schema1 io) where
408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where
390
409
391 manipulateParams
410 manipulateParams
392− (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =
411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =
393 PQ $ \ (K conn) -> do
412 PQ $ \ (K conn) -> do
394 let
413 let
395− 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
396− params' = fmap (fmap toParam') (hcollapse (toParams @x @ps params))
424+ $ toParams @x @ps params
425+ q' = q <> ";"
397− resultMaybe <- liftBase $ LibPQ.execParams conn q params' LibPQ.Binary
426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary
398 case resultMaybe of
427 case resultMaybe of
399− Nothing -> error
428+ Nothing -> throw $ ResultException
400 "manipulateParams: LibPQ.execParams returned no results"
429 "manipulateParams: LibPQ.execParams returned no results"
430+ Just result -> do
431+ okResult_ result
401− Just result -> return $ K (K result)
432+ return $ K (K result)
402
433
403 traversePrepared
434 traversePrepared
404− (UnsafeManipulation q :: Manipulation schema xs ys) (list :: list x) =
435+ (UnsafeManipulation q :: Manipulation '[] schemas xs ys) (list :: list x) =
405− PQ $ \ (K conn) -> liftBase $ do
436+ PQ $ \ (K conn) -> liftIO $ do
437+ let
406− 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
407− prepResultMaybe <- LibPQ.prepare conn temp q Nothing
445+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')
408 case prepResultMaybe of
446 case prepResultMaybe of
409− Nothing -> error
447+ Nothing -> throw $ ResultException
410 "traversePrepared: LibPQ.prepare returned no results"
448 "traversePrepared: LibPQ.prepare returned no results"
411− Just prepResult -> do
449+ Just prepResult -> okResult_ prepResult
412− status <- LibPQ.resultStatus prepResult
413− unless (status == LibPQ.CommandOk) . error $
414− "traversePrepared: LibPQ.prepare status " <> show status
415 results <- for list $ \ params -> do
450 results <- for list $ \ params -> do
416 let
451 let
417− toParam' bytes = (bytes,LibPQ.Binary)
452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)
418 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
453 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
419 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
454 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
420 case resultMaybe of
455 case resultMaybe of
421− Nothing -> error
456+ Nothing -> throw $ ResultException
422 "traversePrepared: LibPQ.execParams returned no results"
457 "traversePrepared: LibPQ.execParams returned no results"
458+ Just result -> do
459+ okResult_ result
423− Just result -> return $ K result
460+ return $ K result
424 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
425 case deallocResultMaybe of
462 case deallocResultMaybe of
426− Nothing -> error
463+ Nothing -> throw $ ResultException
427 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
428− Just deallocResult -> do
465+ Just deallocResult -> okResult_ deallocResult
429− status <- LibPQ.resultStatus deallocResult
430− unless (status == LibPQ.CommandOk) . error $
431− "traversePrepared: DEALLOCATE status " <> show status
432 return (K results)
466 return (K results)
433
467
434 traversePrepared_
468 traversePrepared_
435− (UnsafeManipulation q :: Manipulation schema xs '[]) (list :: list x) =
469+ (UnsafeManipulation q :: Manipulation '[] schemas xs '[]) (list :: list x) =
436− PQ $ \ (K conn) -> liftBase $ do
470+ PQ $ \ (K conn) -> liftIO $ do
471+ let
437− 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
438− prepResultMaybe <- LibPQ.prepare conn temp q Nothing
479+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')
439 case prepResultMaybe of
480 case prepResultMaybe of
440− Nothing -> error
481+ Nothing -> throw $ ResultException
441 "traversePrepared_: LibPQ.prepare returned no results"
482 "traversePrepared_: LibPQ.prepare returned no results"
442− Just prepResult -> do
483+ Just prepResult -> okResult_ prepResult
443− status <- LibPQ.resultStatus prepResult
444− unless (status == LibPQ.CommandOk) . error $
445− "traversePrepared: LibPQ.prepare status " <> show status
446 for_ list $ \ params -> do
484 for_ list $ \ params -> do
447 let
485 let
448− toParam' bytes = (bytes,LibPQ.Binary)
486+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)
449 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
487 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))
450 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
488 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary
451 case resultMaybe of
489 case resultMaybe of
452− Nothing -> error
490+ Nothing -> throw $ ResultException
453 "traversePrepared_: LibPQ.execParams returned no results"
491 "traversePrepared_: LibPQ.execParams returned no results"
454− Just _result -> return ()
492+ Just result -> okResult_ result
455 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
493 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")
456 case deallocResultMaybe of
494 case deallocResultMaybe of
457− Nothing -> error
495+ Nothing -> throw $ ResultException
458 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
496 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"
459− Just deallocResult -> do
497+ Just deallocResult -> okResult_ deallocResult
460− status <- LibPQ.resultStatus deallocResult
461− unless (status == LibPQ.CommandOk) . error $
462− "traversePrepared: DEALLOCATE status " <> show status
463 return (K ())
498 return (K ())
464
499
465 liftPQ pq = PQ $ \ (K conn) -> do
500 liftPQ pq = PQ $ \ (K conn) -> do
466− y <- liftBase $ pq conn
501+ y <- liftIO $ pq conn
467 return (K y)
502 return (K y)
468
503
469−instance MonadPQ schema m => MonadPQ schema (IdentityT m)
504+instance MonadPQ schemas m => MonadPQ schemas (IdentityT m)
470−instance MonadPQ schema m => MonadPQ schema (ReaderT r m)
505+instance MonadPQ schemas m => MonadPQ schemas (ReaderT r m)
471−instance MonadPQ schema m => MonadPQ schema (Strict.StateT s m)
506+instance MonadPQ schemas m => MonadPQ schemas (Strict.StateT s m)
472−instance MonadPQ schema m => MonadPQ schema (Lazy.StateT s m)
507+instance MonadPQ schemas m => MonadPQ schemas (Lazy.StateT s m)
473−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)
474−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)
475−instance MonadPQ schema m => MonadPQ schema (MaybeT m)
510+instance MonadPQ schemas m => MonadPQ schemas (MaybeT m)
476−instance MonadPQ schema m => MonadPQ schema (ExceptT e m)
511+instance MonadPQ schemas m => MonadPQ schemas (ExceptT e m)
477−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)
478−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)
479−instance MonadPQ schema m => MonadPQ schema (ContT r m)
514+instance MonadPQ schemas m => MonadPQ schemas (ContT r m)
480−instance MonadPQ schema m => MonadPQ schema (ListT m)
515+
481−
482−instance (Monad m, schema0 ~ schema1)
516+instance (Monad m, schemas0 ~ schemas1)
483− => Applicative (PQ schema0 schema1 m) where
517+ => Applicative (PQ schemas0 schemas1 m) where
484 pure x = PQ $ \ _conn -> pure (K x)
518 pure x = PQ $ \ _conn -> pure (K x)
485 (<*>) = pqAp
519 (<*>) = pqAp
486
520
487−instance (Monad m, schema0 ~ schema1)
521+instance (Monad m, schemas0 ~ schemas1)
488− => Monad (PQ schema0 schema1 m) where
522+ => Monad (PQ schemas0 schemas1 m) where
489 return = pure
523 return = pure
490 (>>=) = flip pqBind
524 (>>=) = flip pqBind
491
525
492−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
493 hoist f (PQ pq) = PQ (f . pq)
531 hoist f (PQ pq) = PQ (f . pq)
494
532
495−instance schema0 ~ schema1 => MonadTrans (PQ schema0 schema1) where
533+instance schemas0 ~ schemas1 => MonadTrans (PQ schemas0 schemas1) where
496 lift m = PQ $ \ _conn -> do
534 lift m = PQ $ \ _conn -> do
497 x <- m
535 x <- m
498 return (K x)
536 return (K x)
499
537
500−instance schema0 ~ schema1 => MMonad (PQ schema0 schema1) where
538+instance schemas0 ~ schemas1 => MMonad (PQ schemas0 schemas1) where
501 embed f (PQ pq) = PQ $ \ conn -> do
539 embed f (PQ pq) = PQ $ \ conn -> do
502 evalPQ (f (pq conn)) conn
540 evalPQ (f (pq conn)) conn
503
541
504−instance (MonadBase b m, schema0 ~ schema1)
542+instance (MonadIO m, schema0 ~ schema1)
505− => MonadBase b (PQ schema0 schema1 m) where
543+ => MonadIO (PQ schema0 schema1 m) where
506− liftBase = lift . liftBase
544+ liftIO = lift . liftIO
507−
508−-- | A snapshot of the state of a `PQ` computation.
509−type PQRun schema =
510− forall m x. Monad m => PQ schema schema m x -> m (K x schema)
511−
512−-- | Helper function in defining `MonadBaseControl` instance for `PQ`.
513−pqliftWith :: Functor m => (PQRun schema -> m a) -> PQ schema schema m a
514−pqliftWith f = PQ $ \ conn ->
515− fmap K (f $ \ pq -> unPQ pq conn)
516
545
517−instance (MonadBaseControl b m, schema0 ~ schema1)
546+instance (MonadUnliftIO m, schemas0 ~ schemas1)
518− => MonadBaseControl b (PQ schema0 schema1 m) where
547+ => MonadUnliftIO (PQ schemas0 schemas1 m) where
519− type StM (PQ schema0 schema1 m) x = StM m (K x schema0)
548+ withRunInIO
520− liftBaseWith f =
549+ :: ((forall a . PQ schemas0 schema1 m a -> IO a) -> IO b)
521− pqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run
550+ -> PQ schemas0 schema1 m b
522− restoreM = PQ . const . restoreM
551+ withRunInIO inner = PQ $ \conn ->
552+ withRunInIO $ \(run :: (forall x . m x -> IO x)) ->
553+ K <$> inner (\pq -> run $ unK <$> unPQ pq conn)
523
554
524-- | 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`,
525-- throwing an exception if the row number is out of bounds.
556-- throwing an exception if the row number is out of bounds.
526getRow
557getRow
527− :: (FromRow columns y, MonadBase IO io)
558+ :: (FromRow columns y, MonadIO io)
528 => LibPQ.Row
559 => LibPQ.Row
529 -- ^ row number
560 -- ^ row number
530 -> K LibPQ.Result columns
561 -> K LibPQ.Result columns
531 -- ^ result
562 -- ^ result
532 -> io y
563 -> io y
533−getRow r (K result :: K LibPQ.Result columns) = liftBase $ do
564+getRow r (K result :: K LibPQ.Result columns) = liftIO $ do
534 numRows <- LibPQ.ntuples result
565 numRows <- LibPQ.ntuples result
535− when (numRows < r) $ error $
566+ when (numRows < r) $ throw $ ResultException $
536− "getRow: expected at least " <> show r <> "rows but only saw "
567+ "getRow: expected at least " <> pack (show r) <> "rows but only saw "
537− <> show numRows
568+ <> pack (show numRows)
538 let len = fromIntegral (lengthSList (Proxy @columns))
569 let len = fromIntegral (lengthSList (Proxy @columns))
539 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
570 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
540 case fromList row' of
571 case fromList row' of
541− Nothing -> error "getRow: found unexpected length"
572+ Nothing -> throw $ ResultException "getRow: found unexpected length"
542− 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
543
576
544-- | Intended to be used for unfolding in streaming libraries, `nextRow`
577-- | Intended to be used for unfolding in streaming libraries, `nextRow`
545-- 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`)
546-- 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`,
547-- otherwise returning the row along with the next row number.
580-- otherwise returning the row along with the next row number.
548nextRow
581nextRow
549− :: (FromRow columns y, MonadBase IO io)
582+ :: (FromRow columns y, MonadIO io)
550 => LibPQ.Row -- ^ total number of rows
583 => LibPQ.Row -- ^ total number of rows
551 -> K LibPQ.Result columns -- ^ result
584 -> K LibPQ.Result columns -- ^ result
552 -> LibPQ.Row -- ^ row number
585 -> LibPQ.Row -- ^ row number
553 -> io (Maybe (LibPQ.Row,y))
586 -> io (Maybe (LibPQ.Row,y))
554nextRow total (K result :: K LibPQ.Result columns) r
587nextRow total (K result :: K LibPQ.Result columns) r
555− = liftBase $ if r >= total then return Nothing else do
588+ = liftIO $ if r >= total then return Nothing else do
556 let len = fromIntegral (lengthSList (Proxy @columns))
589 let len = fromIntegral (lengthSList (Proxy @columns))
557 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
590 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
558 case fromList row' of
591 case fromList row' of
559− 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
560− Just row -> return $ Just (r+1, fromRow @columns row)
595+ Right y -> return $ Just (r+1, y)
561
596
562-- | Get all rows from a `LibPQ.Result`.
597-- | Get all rows from a `LibPQ.Result`.
563getRows
598getRows
564− :: (FromRow columns y, MonadBase IO io)
599+ :: (FromRow columns y, MonadIO io)
565 => K LibPQ.Result columns -- ^ result
600 => K LibPQ.Result columns -- ^ result
566 -> io [y]
601 -> io [y]
567−getRows (K result :: K LibPQ.Result columns) = liftBase $ do
602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do
568 let len = fromIntegral (lengthSList (Proxy @columns))
603 let len = fromIntegral (lengthSList (Proxy @columns))
569 numRows <- LibPQ.ntuples result
604 numRows <- LibPQ.ntuples result
570 for [0 .. numRows - 1] $ \ r -> do
605 for [0 .. numRows - 1] $ \ r -> do
571 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
606 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]
572 case fromList row' of
607 case fromList row' of
573− Nothing -> error "getRows: found unexpected length"
608+ Nothing -> throw $ ResultException "getRows: found unexpected length"
574− 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
575
612
576-- | Get the first row if possible from a `LibPQ.Result`.
613-- | Get the first row if possible from a `LibPQ.Result`.
577firstRow
614firstRow
578− :: (FromRow columns y, MonadBase IO io)
615+ :: (FromRow columns y, MonadIO io)
579 => K LibPQ.Result columns -- ^ result
616 => K LibPQ.Result columns -- ^ result
580 -> io (Maybe y)
617 -> io (Maybe y)
581−firstRow (K result :: K LibPQ.Result columns) = liftBase $ do
618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do
582 numRows <- LibPQ.ntuples result
619 numRows <- LibPQ.ntuples result
583 if numRows <= 0 then return Nothing else do
620 if numRows <= 0 then return Nothing else do
584 let len = fromIntegral (lengthSList (Proxy @columns))
621 let len = fromIntegral (lengthSList (Proxy @columns))
585 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]
622 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]
586 case fromList row' of
623 case fromList row' of
587− Nothing -> error "firstRow: found unexpected length"
624+ Nothing -> throw $ ResultException "firstRow: found unexpected length"
588− 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
589
628
590-- | Lifts actions on results from @LibPQ@.
629-- | Lifts actions on results from @LibPQ@.
591liftResult
630liftResult
592− :: MonadBase IO io
631+ :: MonadIO io
593 => (LibPQ.Result -> IO x)
632 => (LibPQ.Result -> IO x)
594 -> K LibPQ.Result results -> io x
633 -> K LibPQ.Result results -> io x
595−liftResult f (K result) = liftBase $ f result
634+liftResult f (K result) = liftIO $ f result
596
635
597-- | Returns the number of rows (tuples) in the query result.
636-- | Returns the number of rows (tuples) in the query result.
598−ntuples :: MonadBase IO io => K LibPQ.Result columns -> io LibPQ.Row
637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row
599ntuples = liftResult LibPQ.ntuples
638ntuples = liftResult LibPQ.ntuples
600
639
601-- | Returns the result status of the command.
640-- | Returns the result status of the command.
602−resultStatus :: MonadBase IO io => K LibPQ.Result results -> io LibPQ.ExecStatus
641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus
603resultStatus = liftResult LibPQ.resultStatus
642resultStatus = liftResult LibPQ.resultStatus
604
643
605-- | Returns the error message most recently generated by an operation
644-- | Returns the error message most recently generated by an operation
606-- on the connection.
645-- on the connection.
607resultErrorMessage
646resultErrorMessage
608− :: MonadBase IO io => K LibPQ.Result results -> io (Maybe ByteString)
647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)
609resultErrorMessage = 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+70−81
@@ -1,18 +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− DataKinds
13− , DeriveFunctor
34+ DeriveFunctor
14 , FlexibleContexts
35 , FlexibleContexts
15 , FlexibleInstances
36 , FlexibleInstances
37+ , InstanceSigs
16 , MultiParamTypeClasses
38 , MultiParamTypeClasses
17 , RankNTypes
39 , RankNTypes
18 , ScopedTypeVariables
40 , ScopedTypeVariables
@@ -23,34 +45,24 @@ A `MonadPQ` for pooled connections.
23
45
24module Squeal.PostgreSQL.Pool
46module Squeal.PostgreSQL.Pool
25 ( -- * Pools
47 ( -- * Pools
26− PoolPQ (..)
48+ Pool
27 , createConnectionPool
49 , createConnectionPool
28− , Pool
50+ , usingConnectionPool
29− , destroyAllResources
51+ , destroyConnectionPool
30− , PoolPQRun
31− , poolpqliftWith
32 ) where
52 ) where
33
53
34−import Control.Monad.Base
35−import Control.Monad.Trans
36−import Control.Monad.Trans.Control
37import Data.ByteString
54import Data.ByteString
38−import Data.Pool
39import Data.Time
55import Data.Time
40−import Generics.SOP (K(..))
56+import Generics.SOP (K(..), unK)
57+import UnliftIO (MonadUnliftIO (..))
58+import UnliftIO.Pool (Pool, createPool, destroyAllResources, withResource)
41
59
42import Squeal.PostgreSQL.PQ
60import Squeal.PostgreSQL.PQ
43−import Squeal.PostgreSQL.Schema
44−
45−-- | `PoolPQ` @schema@ should be a drop-in replacement for `PQ` @schema schema@.
46−newtype PoolPQ (schema :: TablesType) m x =
47− PoolPQ { runPoolPQ :: Pool (K Connection schema) -> m x }
48− deriving Functor
49
61
50-- | Create a striped pool of connections.
62-- | Create a striped pool of connections.
51-- 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.
52createConnectionPool
64createConnectionPool
53− :: MonadBase IO io
65+ :: MonadUnliftIO io
54 => ByteString
66 => ByteString
55 -- ^ 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
56 -- contain one or more parameter settings separated by whitespace.
68 -- contain one or more parameter settings separated by whitespace.
@@ -66,68 +78,45 @@ createConnectionPool
66 -> Int
78 -> Int
67 -- ^ 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.
68 -- 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.
69− -> io (Pool (K Connection schema))
81+ -> io (Pool (K Connection schemas))
70−createConnectionPool conninfo stripes idle maxResrc = liftBase $
82+createConnectionPool conninfo stripes idle maxResrc =
71 createPool (connectdb conninfo) finish stripes idle maxResrc
83 createPool (connectdb conninfo) finish stripes idle maxResrc
72
84
73−-- | `Applicative` instance for `PoolPQ`.
85+{-|
74−instance Monad m => Applicative (PoolPQ schema m) where
86+Temporarily take a connection from a `Pool`, perform an action with it,
75− pure x = PoolPQ $ \ _ -> pure x
87+and return it to the pool afterwards.
76− PoolPQ f <*> PoolPQ x = PoolPQ $ \ pool -> do
77− f' <- f pool
78− x' <- x pool
79− return $ f' x'
80−
81−-- | `Monad` instance for `PoolPQ`.
82−instance Monad m => Monad (PoolPQ schema m) where
83− return = pure
84− PoolPQ x >>= f = PoolPQ $ \ pool -> do
85− x' <- x pool
86− runPoolPQ (f x') pool
87−
88−-- | `MonadTrans` instance for `PoolPQ`.
89−instance MonadTrans (PoolPQ schema) where
90− lift m = PoolPQ $ \ _pool -> m
91−
92−-- | `MonadBase` instance for `PoolPQ`.
93−instance MonadBase b m => MonadBase b (PoolPQ schema m) where
94− liftBase = lift . liftBase
95
88
96−-- | `MonadPQ` instance for `PoolPQ`.
89+If the pool has an idle connection available, it is used immediately.
97−instance MonadBaseControl IO io => MonadPQ schema (PoolPQ schema io) where
90+Otherwise, if the maximum number of connections has not yet been reached,
98− manipulateParams manipulation params = PoolPQ $ \ pool -> do
91+a new connection is created and used.
99− withResource pool $ \ conn -> do
92+If the maximum number of connections has been reached, this function blocks
100− (K result :: K (K Result ys) schema) <- flip unPQ conn $
93+until a connection becomes available.
101− manipulateParams manipulation params
94+-}
102− return result
95+usingConnectionPool
103− traversePrepared manipulation params = PoolPQ $ \ pool ->
96+ :: MonadUnliftIO io
104− withResource pool $ \ conn -> do
97+ => Pool (K Connection schemas) -- ^ pool
105− (K result :: K (list (K Result ys)) schema) <- flip unPQ conn $
98+ -> PQ schemas schemas io x -- ^ session
106− traversePrepared manipulation params
99+ -> io x
107− return result
108− traversePrepared_ manipulation params = PoolPQ $ \ pool -> do
109− withResource pool $ \ conn -> do
110− (_ :: K () schema) <- flip unPQ conn $
111− traversePrepared_ manipulation params
112− return ()
113− liftPQ m = PoolPQ $ \ pool ->
114− withResource pool $ \ conn -> do
100+usingConnectionPool pool (PQ session) = unK <$> withResource pool session
115− (K result :: K result schema) <- flip unPQ conn $
116− liftPQ m
117− return result
118
101
119−-- | A snapshot of the state of a `PoolPQ` computation.
102+{- |
120−type PoolPQRun schema =
103+Destroy all connections in all stripes in the pool.
121− forall m x. Monad m => PoolPQ schema m x -> m x
104+Note that this will ignore any exceptions in the destroy function.
122
105
123−-- | Helper function in defining `MonadBaseControl` instance for `PoolPQ`.
106+This function is useful when you detect that all connections
124−poolpqliftWith :: Functor m => (PoolPQRun schema -> m a) -> PoolPQ schema m a
107+in the pool are broken. For example after a database has been
125−poolpqliftWith f = PoolPQ $ \ pool ->
108+restarted all connections opened before the restart will be broken.
126− (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.
127
112
128−-- | `MonadBaseControl` instance for `PoolPQ`.
113+Another use-case for this function is that when you know you are done
129−instance MonadBaseControl b m => MonadBaseControl b (PoolPQ schema m) where
114+with the pool you can destroy all idle connections immediately
130− type StM (PoolPQ schema m) x = StM m x
115+instead of waiting on the garbage collector to destroy them,
131− liftBaseWith f =
116+thus freeing up those connections sooner.
132− poolpqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run
117+-}
133− 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+726−442
@@ -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
@@ -9,75 +9,81 @@ Squeal queries.
9-}
9-}
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12− DataKinds
12+ ConstraintKinds
13− , DeriveDataTypeable
14 , DeriveGeneric
13 , DeriveGeneric
15 , FlexibleContexts
14 , FlexibleContexts
16 , FlexibleInstances
15 , FlexibleInstances
17 , GADTs
16 , GADTs
18 , GeneralizedNewtypeDeriving
17 , GeneralizedNewtypeDeriving
19− , KindSignatures
20 , LambdaCase
18 , LambdaCase
21 , MultiParamTypeClasses
19 , MultiParamTypeClasses
20+ , OverloadedLabels
22 , OverloadedStrings
21 , OverloadedStrings
22+ , QuantifiedConstraints
23 , ScopedTypeVariables
23 , ScopedTypeVariables
24 , StandaloneDeriving
24 , StandaloneDeriving
25 , TypeApplications
25 , TypeApplications
26+ , TypeFamilies
26 , TypeInType
27 , TypeInType
27 , TypeOperators
28 , TypeOperators
29+ , RankNTypes
28 , UndecidableInstances
30 , UndecidableInstances
29−#-}
31+ #-}
30
32
31module Squeal.PostgreSQL.Query
33module Squeal.PostgreSQL.Query
32 ( -- * Queries
34 ( -- * Queries
33− 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
34 , union
49 , union
35 , unionAll
50 , unionAll
36 , intersect
51 , intersect
37 , intersectAll
52 , intersectAll
38 , except
53 , except
39 , exceptAll
54 , exceptAll
40− -- * Select
55+ -- ** With
41− , select
56+ , With (..)
42− , selectDistinct
57+ , CommonTableExpression (..)
43− , selectStar
58+ , withRecursive
44− , selectDistinctStar
45− , selectDotStar
46− , selectDistinctDotStar
47 -- * Table Expressions
59 -- * Table Expressions
48 , TableExpression (..)
60 , TableExpression (..)
49− , renderTableExpression
50 , from
61 , from
51 , where_
62 , where_
52− , group
63+ , groupBy
53 , having
64 , having
54− , orderBy
55 , limit
65 , limit
56 , offset
66 , offset
57− -- * From
67+ -- * From Clauses
58 , FromClause (..)
68 , FromClause (..)
59 , table
69 , table
60 , subquery
70 , subquery
71+ , view
72+ , common
61 , crossJoin
73 , crossJoin
62 , innerJoin
74 , innerJoin
63 , leftOuterJoin
75 , leftOuterJoin
64 , rightOuterJoin
76 , rightOuterJoin
65 , fullOuterJoin
77 , fullOuterJoin
66 -- * Grouping
78 -- * Grouping
67− , By (By, By2)
79+ , By (..)
68− , renderBy
80+ , GroupByClause (..)
69− , GroupByClause (NoGroups, Group)
81+ , HavingClause (..)
70− , renderGroupByClause
71− , HavingClause (NoHaving, Having)
72− , renderHavingClause
73− -- * Sorting
74− , SortExpression (..)
75− , renderSortExpression
76 ) where
82 ) where
77
83
78import Control.DeepSeq
84import Control.DeepSeq
79import Data.ByteString (ByteString)
85import Data.ByteString (ByteString)
80−import Data.Monoid hiding (All)
86+import Data.Kind (Type)
81import Data.String
87import Data.String
82import Data.Word
88import Data.Word
83import Generics.SOP hiding (from)
89import Generics.SOP hiding (from)
@@ -85,352 +91,577 @@ import GHC.TypeLits
85
91
86import qualified GHC.Generics as GHC
92import qualified GHC.Generics as GHC
87
93
94+import Squeal.PostgreSQL.Alias
88import 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
89import Squeal.PostgreSQL.Render
101import Squeal.PostgreSQL.Render
90import Squeal.PostgreSQL.Schema
102import Squeal.PostgreSQL.Schema
91
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+
92{- |
111{- |
93−The process of retrieving or the command to retrieve data from a database
112+The process of retrieving or the command to retrieve data from
94−is called a `Query`. The `select`, `selectStar`, `selectDotStar`,
113+a database is called a `Query`.
95−`selectDistinct`, `selectDistinctStar` and `selectDistinctDotStar` commands
114+
96−are used to specify queries.
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+
133+{- |
134+The top level `Query_` type is parameterized by a @schemas@ `SchemasType`,
135+against which the query is type-checked, an input @parameters@ Haskell `Type`,
136+and an ouput row Haskell `Type`.
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+:}
97
155
98simple query:
156simple query:
99
157
158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]
159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
100>>> :{
160>>> :{
101let
161let
102− query :: Query
162+ query :: Query_ (Public Schema) () (Row Int32 Int32)
103− '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
163+ query = select Star (from (table #tab))
104− '[]
164+in printSQL query
105− '["col" ::: 'Null 'PGint4]
106− query = selectStar (from (table (#tab `As` #t)))
107−in renderQuery query
108:}
165:}
109−"SELECT * FROM tab AS t"
166+SELECT * FROM "tab" AS "tab"
110
167
111restricted query:
168restricted query:
112
169
113>>> :{
170>>> :{
114let
171let
115− query :: Query
172+ query :: Query_ (Public Schema) () (Row Int32 Int32)
116− '[ "tab" ::: '[] :=>
173+ query =
117− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)
118− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ]]
175+ ( from (table #tab)
119− '[]
120− '[ "sum" ::: 'NotNull 'PGint4
121− , "col1" ::: 'NotNull 'PGint4 ]
122− query =
123− select
124− ((#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)
125− ( from (table (#tab `As` #t))
126 & where_ (#col1 .> #col2)
176 & where_ (#col1 .> #col2)
127 & where_ (#col2 .> 0) )
177 & where_ (#col2 .> 0) )
128−in renderQuery query
178+in printSQL query
129:}
179:}
130−"SELECT (col1 + col2) AS sum, col1 AS col1 FROM tab AS t 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))
131
181
132subquery:
182subquery:
133
183
134>>> :{
184>>> :{
135let
185let
136− query :: Query
186+ query :: Query_ (Public Schema) () (Row Int32 Int32)
137− '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
187+ query = select Star (from (subquery (select Star (from (table #tab)) `as` #sub)))
138− '[]
188+in printSQL query
139− '["col" ::: 'Null 'PGint4]
140− query =
141− selectStar
142− (from (subquery (selectStar (from (table (#tab `As` #t))) `As` #sub)))
143−in renderQuery query
144:}
189:}
145−"SELECT * FROM (SELECT * FROM tab AS t) AS sub"
190+SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"
146
191
147limits and offsets:
192limits and offsets:
148
193
149>>> :{
194>>> :{
150let
195let
151− query :: Query
196+ query :: Query_ (Public Schema) () (Row Int32 Int32)
152− '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
197+ query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)
153− '[]
198+in printSQL query
154− '["col" ::: 'Null 'PGint4]
155− query = selectStar
156− (from (table (#tab `As` #t)) & limit 100 & offset 2 & limit 50 & offset 2)
157−in renderQuery query
158:}
199:}
159−"SELECT * FROM tab AS t LIMIT 50 OFFSET 4"
200+SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4
160
201
161parameterized query:
202parameterized query:
162
203
163>>> :{
204>>> :{
164let
205let
165− query :: Query
206+ query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)
166− '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8]]
207+ query = select Star (from (table #tab) & where_ (#col1 .> param @1))
167− '[ 'NotNull 'PGfloat8]
208+in printSQL query
168− '["col" ::: 'NotNull 'PGfloat8]
169− query = selectStar
170− (from (table (#tab `As` #t)) & where_ (#col .> param @1))
171−in renderQuery query
172:}
209:}
173−"SELECT * FROM tab AS t WHERE (col > ($1 :: float8))"
210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))
174
211
175aggregation query:
212aggregation query:
176
213
177>>> :{
214>>> :{
178let
215let
179− query :: Query
216+ query :: Query_ (Public Schema) () (Row Int64 Int32)
180− '[ "tab" ::: '[] :=>
181− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
182− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ]]
183− '[]
184− '[ "sum" ::: 'NotNull 'PGint4
185− , "col1" ::: 'NotNull 'PGint4 ]
186 query =
217 query =
187− select (sum_ #col2 `As` #sum :* #col1 `As` #col1 :* Nil)
218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)
188− ( from (table (#tab `As` #table1))
219+ ( from (table (#tab `as` #table1))
189− & group (By #col1 :* Nil)
220+ & groupBy #col1
190− & having (#col1 + sum_ #col2 .> 1) )
221+ & having (sum_ (Distinct #col2) .> 1) )
191−in renderQuery query
222+in printSQL query
192:}
223:}
193−"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)
194
225
195sorted query:
226sorted query:
196
227
197>>> :{
228>>> :{
198let
229let
199− query :: Query
230+ query :: Query_ (Public Schema) () (Row Int32 Int32)
200− '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])
201− '[]
232+in printSQL query
202− '["col" ::: 'Null 'PGint4]
203− query = selectStar
204− (from (table (#tab `As` #t)) & orderBy [#col & AscNullsFirst])
205−in renderQuery query
206:}
233:}
207−"SELECT * FROM tab AS t ORDER BY col ASC NULLS FIRST"
234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC
208
235
209joins:
236joins:
210
237
211−>>> :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+
212>>> :{
273>>> :{
213let
274let
214− query :: Query
275+ query :: Query_ (Public OrdersSchema) () Order
215− '[ "orders" :::
276+ query = select_
216− '["pk_orders" ::: PrimaryKey '["id"]
277+ ( #o ! #price `as` #price :*
217− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]
278+ #c ! #name `as` #customerName :*
218− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>
279+ #s ! #name `as` #shipperName )
219− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
280+ ( from (table (#orders `as` #o)
220− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4
281+ & innerJoin (table (#customers `as` #c))
221− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4
222− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4
223− ]
224− , "customers" :::
225− '["pk_customers" ::: PrimaryKey '["id"]] :=>
226− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
227− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
228− ]
229− , "shippers" :::
230− '["pk_shippers" ::: PrimaryKey '["id"]] :=>
231− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
232− , "name" ::: 'NoDef :=> 'NotNull 'PGtext
233− ]
234− ]
235− '[]
236− '[ "order_price" ::: 'NotNull 'PGfloat4
237− , "customer_name" ::: 'NotNull 'PGtext
238− , "shipper_name" ::: 'NotNull 'PGtext
239− ]
240− query = select
241− ( #o ! #price `As` #order_price :*
242− #c ! #name `As` #customer_name :*
243− #s ! #name `As` #shipper_name :* Nil )
244− ( from (table (#orders `As` #o)
245− & innerJoin (table (#customers `As` #c))
246 (#o ! #customer_id .== #c ! #id)
282 (#o ! #customer_id .== #c ! #id)
247− & innerJoin (table (#shippers `As` #s))
283+ & innerJoin (table (#shippers `as` #s))
248 (#o ! #shipper_id .== #s ! #id)) )
284 (#o ! #shipper_id .== #s ! #id)) )
249−in renderQuery query
285+in printSQL query
250:}
286:}
251−"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")
252
288
253self-join:
289self-join:
254
290
255>>> :{
291>>> :{
256let
292let
257− query :: Query
293+ query :: Query_ (Public Schema) () (Row Int32 Int32)
258− '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
294+ query = select
259− '[]
295+ (#t1 & DotStar)
260− '["col" ::: 'Null 'PGint4]
296+ (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))
261− query = selectDotStar #t1
297+in printSQL query
262− (from (table (#tab `As` #t1) & crossJoin (table (#tab `As` #t2))))
263−in renderQuery query
264:}
298:}
265−"SELECT t1.* FROM tab AS t1 CROSS JOIN tab AS t2"
299+SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"
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")
266
312
267set operations:
313set operations:
268
314
269>>> :{
315>>> :{
270let
316let
271− query :: Query
317+ query :: Query_ (Public Schema) () (Row Int32 Int32)
272− '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
318+ query = select Star (from (table #tab)) `unionAll` select Star (from (table #tab))
273− '[]
319+in printSQL query
274− '["col" ::: 'Null 'PGint4]
320+:}
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)
275 query =
353 query =
276− selectStar (from (table (#tab `As` #t)))
354+ select (#col1 `as` #fromOnly) (from (table (#tab `as` #t1))
277− `unionAll`
355+ & where_ (exists (
278− selectStar (from (table (#tab `As` #t)))
356+ select Star (from (table (#tab `as` #t2))
279−in renderQuery query
357+ & where_ (#t2 ! #col2 .== #t1 ! #col1)))))
358+in printSQL query
280:}
359:}
281−"(SELECT * FROM tab AS t) UNION ALL (SELECT * FROM tab AS t)"
360+SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))
361+
282-}
362-}
283−newtype Query
363+type family Query_
284− (schema :: TablesType)
364+ (schemas :: SchemasType)
285− (params :: [NullityType])
365+ (parameters :: Type)
286− (columns :: RelationType)
366+ (row :: Type) where
287− = UnsafeQuery { renderQuery :: ByteString }
367+ Query_ schemas params row =
288− deriving (GHC.Generic,Show,Eq,Ord,NFData)
368+ Query '[] '[] schemas (TuplePG params) (RowPG row)
289
369
290-- | 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
291−-- `union`. Duplicate rows are eliminated.
371+-- `union`. Duplicate rows are eliminated.
292union
372union
293− :: Query schema params columns
373+ :: Query outer commons schemas params columns
294− -> Query schema params columns
374+ -> Query outer commons schemas params columns
295− -> Query schema params columns
375+ -> Query outer commons schemas params columns
296q1 `union` q2 = UnsafeQuery $
376q1 `union` q2 = UnsafeQuery $
297− parenthesized (renderQuery q1)
377+ parenthesized (renderSQL q1)
298 <+> "UNION"
378 <+> "UNION"
299− <+> parenthesized (renderQuery q2)
379+ <+> parenthesized (renderSQL q2)
300
380
301-- | 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
302-- `unionAll`, the disjoint union. Duplicate rows are retained.
382-- `unionAll`, the disjoint union. Duplicate rows are retained.
303unionAll
383unionAll
304− :: Query schema params columns
384+ :: Query outer commons schemas params columns
305− -> Query schema params columns
385+ -> Query outer commons schemas params columns
306− -> Query schema params columns
386+ -> Query outer commons schemas params columns
307q1 `unionAll` q2 = UnsafeQuery $
387q1 `unionAll` q2 = UnsafeQuery $
308− parenthesized (renderQuery q1)
388+ parenthesized (renderSQL q1)
309 <+> "UNION" <+> "ALL"
389 <+> "UNION" <+> "ALL"
310− <+> parenthesized (renderQuery q2)
390+ <+> parenthesized (renderSQL q2)
311
391
312-- | 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
313-- `intersect`, the intersection. Duplicate rows are eliminated.
393-- `intersect`, the intersection. Duplicate rows are eliminated.
314intersect
394intersect
315− :: Query schema params columns
395+ :: Query outer commons schemas params columns
316− -> Query schema params columns
396+ -> Query outer commons schemas params columns
317− -> Query schema params columns
397+ -> Query outer commons schemas params columns
318q1 `intersect` q2 = UnsafeQuery $
398q1 `intersect` q2 = UnsafeQuery $
319− parenthesized (renderQuery q1)
399+ parenthesized (renderSQL q1)
320 <+> "INTERSECT"
400 <+> "INTERSECT"
321− <+> parenthesized (renderQuery q2)
401+ <+> parenthesized (renderSQL q2)
322
402
323-- | 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
324-- `intersectAll`, the intersection. Duplicate rows are retained.
404-- `intersectAll`, the intersection. Duplicate rows are retained.
325intersectAll
405intersectAll
326− :: Query schema params columns
406+ :: Query outer commons schemas params columns
327− -> Query schema params columns
407+ -> Query outer commons schemas params columns
328− -> Query schema params columns
408+ -> Query outer commons schemas params columns
329q1 `intersectAll` q2 = UnsafeQuery $
409q1 `intersectAll` q2 = UnsafeQuery $
330− parenthesized (renderQuery q1)
410+ parenthesized (renderSQL q1)
331 <+> "INTERSECT" <+> "ALL"
411 <+> "INTERSECT" <+> "ALL"
332− <+> parenthesized (renderQuery q2)
412+ <+> parenthesized (renderSQL q2)
333
413
334-- | 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
335-- `except`, the set difference. Duplicate rows are eliminated.
415-- `except`, the set difference. Duplicate rows are eliminated.
336except
416except
337− :: Query schema params columns
417+ :: Query outer commons schemas params columns
338− -> Query schema params columns
418+ -> Query outer commons schemas params columns
339− -> Query schema params columns
419+ -> Query outer commons schemas params columns
340q1 `except` q2 = UnsafeQuery $
420q1 `except` q2 = UnsafeQuery $
341− parenthesized (renderQuery q1)
421+ parenthesized (renderSQL q1)
342 <+> "EXCEPT"
422 <+> "EXCEPT"
343− <+> parenthesized (renderQuery q2)
423+ <+> parenthesized (renderSQL q2)
344
424
345-- | 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
346-- `exceptAll`, the set difference. Duplicate rows are retained.
426-- `exceptAll`, the set difference. Duplicate rows are retained.
347exceptAll
427exceptAll
348− :: Query schema params columns
428+ :: Query outer commons schemas params columns
349− -> Query schema params columns
429+ -> Query outer commons schemas params columns
350− -> Query schema params columns
430+ -> Query outer commons schemas params columns
351q1 `exceptAll` q2 = UnsafeQuery $
431q1 `exceptAll` q2 = UnsafeQuery $
352− parenthesized (renderQuery q1)
432+ parenthesized (renderSQL q1)
353 <+> "EXCEPT" <+> "ALL"
433 <+> "EXCEPT" <+> "ALL"
354− <+> parenthesized (renderQuery q2)
434+ <+> parenthesized (renderSQL q2)
355
435
356{-----------------------------------------
436{-----------------------------------------
357SELECT queries
437SELECT queries
358-----------------------------------------}
438-----------------------------------------}
359
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+
360-- | the `TableExpression` in the `select` command constructs an intermediate
525-- | the `TableExpression` in the `select` command constructs an intermediate
361-- virtual table by possibly combining tables, views, eliminating rows,
526-- virtual table by possibly combining tables, views, eliminating rows,
362-- grouping, etc. This table is finally passed on to processing by
527-- grouping, etc. This table is finally passed on to processing by
363−-- the select list. The select list determines which columns of
528+-- the select list. The `Selection` determines which columns of
364-- the intermediate table are actually output.
529-- the intermediate table are actually output.
365select
530select
366− :: SListI columns
531+ :: (SListI row, row ~ (x ': xs))
367− => NP (Aliased (Expression relations grouping params)) (column ': columns)
532+ => Selection outer commons grp schemas params from row
368− -- ^ select list
533+ -- ^ selection
369− -> TableExpression schema params relations grouping
534+ -> TableExpression outer commons grp schemas params from
370 -- ^ intermediate virtual table
535 -- ^ intermediate virtual table
371− -> Query schema params (column ': columns)
536+ -> Query outer commons schemas params row
372−select list rels = UnsafeQuery $
537+select selection tabexpr = UnsafeQuery $
373 "SELECT"
538 "SELECT"
374− <+> renderCommaSeparated (renderAliasedAs renderExpression) list
539+ <+> renderSQL selection
375− <+> 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
376
552
377-- | After the select list has been processed, the result table can
553-- | After the select list has been processed, the result table can
378-- be subject to the elimination of duplicate rows using `selectDistinct`.
554-- be subject to the elimination of duplicate rows using `selectDistinct`.
379selectDistinct
555selectDistinct
380− :: SListI columns
556+ :: (SListI columns, columns ~ (col ': cols))
381− => NP (Aliased (Expression relations 'Ungrouped params)) (column ': columns)
557+ => Selection outer commons grp schemas params from columns
382− -- ^ select list
558+ -- ^ selection
383− -> TableExpression schema params relations 'Ungrouped
559+ -> TableExpression outer commons grp schemas params from
384 -- ^ intermediate virtual table
560 -- ^ intermediate virtual table
385− -> Query schema params (column ': columns)
561+ -> Query outer commons schemas params columns
386−selectDistinct list rels = UnsafeQuery $
562+selectDistinct selection tabexpr = UnsafeQuery $
387 "SELECT DISTINCT"
563 "SELECT DISTINCT"
388− <+> renderCommaSeparated (renderAliasedAs renderExpression) list
564+ <+> renderSQL selection
389− <+> renderTableExpression rels
565+ <+> renderSQL tabexpr
390−
566+
391−-- | The simplest kind of query is `selectStar` which emits all columns
567+-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead
392−-- that the table expression produces.
568+-- of a general `Selection`.
393−selectStar
569+selectDistinct_
394− :: HasUnique relation relations columns
570+ :: (SListI columns, columns ~ (col ': cols))
395− => TableExpression schema params relations 'Ungrouped
571+ => NP (Aliased (Expression outer commons grp schemas params from)) columns
396− -- ^ intermediate virtual table
572+ -- ^ select list
397− -> Query schema params columns
573+ -> TableExpression outer commons grp schemas params from
398−selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels
399−
400−-- | A `selectDistinctStar` emits all columns that the table expression
401−-- produces and eliminates duplicate rows.
402−selectDistinctStar
403− :: HasUnique relation relations columns
404− => TableExpression schema params relations 'Ungrouped
405 -- ^ intermediate virtual table
574 -- ^ intermediate virtual table
406− -> Query schema params columns
575+ -> Query outer commons schemas params columns
407−selectDistinctStar rels = UnsafeQuery $
576+selectDistinct_ = selectDistinct . List
408− "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels
577+
409−
578+{-|
410−-- | 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
411−-- for all the columns of a particular table, using `selectDotStar`.
580+the given expressions evaluate to equal. The DISTINCT ON expressions are
412−selectDotStar
581+interpreted using the same rules as for ORDER BY. ORDER BY is used to
413− :: Has relation relations columns
582+ensure that the desired row appears first.
414− => Alias relation
583+
415− -- ^ particular virtual subtable
584+The DISTINCT ON expression(s) must match the leftmost ORDER BY expression(s).
416− -> 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
417 -- ^ intermediate virtual table
598 -- ^ intermediate virtual table
418− -> Query schema params columns
599+ -> Query outer commons schemas params columns
419−selectDotStar rel relations = UnsafeQuery $
600+selectDistinctOn distincts selection tab = UnsafeQuery $
420− "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression relations
601+ "SELECT DISTINCT ON"
421−
602+ <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))
422−-- | A `selectDistinctDotStar` asks for all the columns of a particular table,
603+ <+> renderSQL selection
423−-- and eliminates duplicate rows.
604+ <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})
424−selectDistinctDotStar
605+ where
425− :: Has relation relations columns
606+ renderDistinctOn = \case
426− => Alias relation
607+ Asc expression -> renderSQL expression
427− -- ^ particular virtual table
608+ Desc expression -> renderSQL expression
428− -> 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
429 -- ^ intermediate virtual table
623 -- ^ intermediate virtual table
430− -> Query schema params columns
624+ -> Query outer commons schemas params columns
431−selectDistinctDotStar rel relations = UnsafeQuery $
625+selectDistinctOn_ distincts = selectDistinctOn distincts . List
432− "SELECT DISTINCT" <+> renderAlias rel <> ".*"
626+
433− <+> renderTableExpression relations
627+-- | `values` computes a row value or set of row values
628+-- specified by value expressions. It is most commonly used
629+-- to generate a “constant table” within a larger command,
630+-- but it can be used on its own.
631+--
632+-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]
633+-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query outer commons schemas '[] Row
634+-- >>> printSQL query
635+-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")
636+values
637+ :: SListI cols
638+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols
639+ -> [NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols]
640+ -- ^ When more than one row is specified, all the rows must
641+ -- must have the same number of elements
642+ -> Query outer commons schemas params cols
643+values rw rws = UnsafeQuery $ "SELECT * FROM"
644+ <+> parenthesized (
645+ "VALUES"
646+ <+> commaSeparated
647+ ( parenthesized
648+ . renderCommaSeparated renderValuePart <$> rw:rws )
649+ ) <+> "AS t"
650+ <+> parenthesized (renderCommaSeparated renderAliasPart rw)
651+ where
652+ renderAliasPart, renderValuePart
653+ :: Aliased (Expression outer commons 'Ungrouped schemas params '[] ) ty -> ByteString
654+ renderAliasPart (_ `As` name) = renderSQL name
655+ renderValuePart (value `As` _) = renderSQL value
656+
657+-- | `values_` computes a row value or set of row values
658+-- specified by value expressions.
659+values_
660+ :: SListI cols
661+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols
662+ -- ^ one row of values
663+ -> Query outer commons schemas params cols
664+values_ rw = values rw []
434
665
435{-----------------------------------------
666{-----------------------------------------
436Table Expressions
667Table Expressions
@@ -443,15 +674,17 @@ Table Expressions
443-- 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
444-- 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.
445data TableExpression
676data TableExpression
446− (schema :: TablesType)
677+ (outer :: FromType)
678+ (commons :: FromType)
679+ (grp :: Grouping)
680+ (schemas :: SchemasType)
447 (params :: [NullityType])
681 (params :: [NullityType])
448− (relations :: RelationsType)
682+ (from :: FromType)
449− (grouping :: Grouping)
450 = TableExpression
683 = TableExpression
451− { fromClause :: FromClause schema params relations
684+ { fromClause :: FromClause outer commons schemas params from
452 -- ^ 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
453 -- as a subquery, a @JOIN@ construct, or complex combinations of these.
686 -- as a subquery, a @JOIN@ construct, or complex combinations of these.
454− , whereClause :: [Condition relations 'Ungrouped params]
687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]
455 -- ^ optional search coditions, combined with `.&&`. After the processing
688 -- ^ optional search coditions, combined with `.&&`. After the processing
456 -- 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
457 -- is checked against the search condition. If the result of the
690 -- is checked against the search condition. If the result of the
@@ -460,20 +693,20 @@ data TableExpression
460 -- at least one column of the table generated in the `fromClause`;
693 -- at least one column of the table generated in the `fromClause`;
461 -- this is not required, but otherwise the WHERE clause will
694 -- this is not required, but otherwise the WHERE clause will
462 -- be fairly useless.
695 -- be fairly useless.
463− , groupByClause :: GroupByClause relations grouping
696+ , groupByClause :: GroupByClause grp from
464 -- ^ 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
465 -- 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
466 -- 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
467 -- 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
468 -- 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
469 -- and/or compute aggregates that apply to these groups.
702 -- and/or compute aggregates that apply to these groups.
470− , havingClause :: HavingClause relations grouping params
703+ , havingClause :: HavingClause outer commons grp schemas params from
471 -- ^ 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
472 -- are of interest, the `havingClause` can be used, much like a
705 -- are of interest, the `havingClause` can be used, much like a
473 -- `whereClause`, to eliminate groups from the result. Expressions in the
706 -- `whereClause`, to eliminate groups from the result. Expressions in the
474 -- `havingClause` can refer both to grouped expressions and to ungrouped
707 -- `havingClause` can refer both to grouped expressions and to ungrouped
475 -- expressions (which necessarily involve an aggregate function).
708 -- expressions (which necessarily involve an aggregate function).
476− , orderByClause :: [SortExpression relations grouping params]
709+ , orderByClause :: [SortExpression outer commons grp schemas params from]
477 -- ^ The `orderByClause` is for optional sorting. When more than one
710 -- ^ The `orderByClause` is for optional sorting. When more than one
478 -- `SortExpression` is specified, the later (right) values are used to sort
711 -- `SortExpression` is specified, the later (right) values are used to sort
479 -- rows that are equal according to the earlier (left) values.
712 -- rows that are equal according to the earlier (left) values.
@@ -483,72 +716,69 @@ data TableExpression
483 -- will be returned (but possibly fewer, if the query itself yields
716 -- will be returned (but possibly fewer, if the query itself yields
484 -- fewer rows).
717 -- fewer rows).
485 , offsetClause :: [Word64]
718 , offsetClause :: [Word64]
486− -- ^ The `offsetClause` is combined with `+` to give an offset count
719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count
487 -- 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
488 -- 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
489 -- is applied.
722 -- is applied.
490− }
723+ } deriving (GHC.Generic)
491
724
492-- | Render a `TableExpression`
725-- | Render a `TableExpression`
493−renderTableExpression
726+instance RenderSQL (TableExpression outer commons grp schemas params from) where
494− :: TableExpression schema params relations grouping
727+ renderSQL
495− -> ByteString
728+ (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat
496−renderTableExpression
729+ [ "FROM ", renderSQL frm'
497− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat
730+ , renderWheres whs'
498− [ "FROM ", renderFromClause frm'
731+ , renderSQL grps'
499− , renderWheres whs'
732+ , renderSQL hvs'
500− , renderGroupByClause grps'
733+ , renderOrderByClause srts'
501− , renderHavingClause hvs'
734+ , renderLimits lims'
502− , renderOrderByClause srts'
735+ , renderOffsets offs' ]
503− , renderLimits lims'
736+ where
504− , renderOffsets offs'
737+ renderWheres = \case
505− ]
738+ [] -> ""
506− where
739+ wh:[] -> " WHERE" <+> renderSQL wh
507− renderWheres = \case
740+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)
508− [] -> ""
741+ renderOrderByClause = \case
509− wh:[] -> " WHERE" <+> renderExpression wh
742+ [] -> ""
510− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)
743+ srts -> " ORDER BY"
511− renderOrderByClause = \case
744+ <+> commaSeparated (renderSQL <$> srts)
512− [] -> ""
745+ renderLimits = \case
513− srts -> " ORDER BY"
746+ [] -> ""
514− <+> commaSeparated (renderSortExpression <$> srts)
747+ lims -> " LIMIT" <+> fromString (show (minimum lims))
515− renderLimits = \case
748+ renderOffsets = \case
516− [] -> ""
749+ [] -> ""
517− lims -> " LIMIT" <+> fromString (show (minimum lims))
750+ offs -> " OFFSET" <+> fromString (show (sum offs))
518− renderOffsets = \case
519− [] -> ""
520− offs -> " OFFSET" <+> fromString (show (sum offs))
521
751
522-- | 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
523-- 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,
524-- 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_`,
525−-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
526-- 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.
527from
757from
528− :: FromClause schema params relations -- ^ table reference
758+ :: FromClause outer commons schemas params from -- ^ table reference
529− -> TableExpression schema params relations 'Ungrouped
759+ -> TableExpression outer commons 'Ungrouped schemas params from
530−from rels = TableExpression rels [] NoGroups NoHaving [] [] []
760+from tab = TableExpression tab [] noGroups NoHaving [] [] []
531
761
532-- | A `where_` is an endomorphism of `TableExpression`s which adds a
762-- | A `where_` is an endomorphism of `TableExpression`s which adds a
533-- search condition to the `whereClause`.
763-- search condition to the `whereClause`.
534where_
764where_
535− :: Condition relations 'Ungrouped params -- ^ filtering condition
765+ :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition
536− -> TableExpression schema params relations grouping
766+ -> TableExpression outer commons grp schemas params from
537− -> TableExpression schema params relations grouping
767+ -> TableExpression outer commons grp schemas params from
538where_ wh rels = rels {whereClause = wh : whereClause rels}
768where_ wh rels = rels {whereClause = wh : whereClause rels}
539
769
540−-- | A `group` is a transformation of `TableExpression`s which switches
770+-- | A `groupBy` is a transformation of `TableExpression`s which switches
541−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform
771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform
542-- a "grand total" aggregation query.
772-- a "grand total" aggregation query.
543−group
773+groupBy
544 :: SListI bys
774 :: SListI bys
545− => NP (By relations) bys -- ^ grouped columns
775+ => NP (By from) bys -- ^ grouped columns
546− -> TableExpression schema params relations 'Ungrouped
776+ -> TableExpression outer commons 'Ungrouped schemas params from
547− -> TableExpression schema params relations ('Grouped bys)
777+ -> TableExpression outer commons ('Grouped bys) schemas params from
548−group bys rels = TableExpression
778+groupBy bys rels = TableExpression
549 { fromClause = fromClause rels
779 { fromClause = fromClause rels
550 , whereClause = whereClause rels
780 , whereClause = whereClause rels
551− , groupByClause = Group bys
781+ , groupByClause = group bys
552 , havingClause = Having []
782 , havingClause = Having []
553 , orderByClause = []
783 , orderByClause = []
554 , limitClause = limitClause rels
784 , limitClause = limitClause rels
@@ -558,34 +788,29 @@ group bys rels = TableExpression
558-- | A `having` is an endomorphism of `TableExpression`s which adds a
788-- | A `having` is an endomorphism of `TableExpression`s which adds a
559-- search condition to the `havingClause`.
789-- search condition to the `havingClause`.
560having
790having
561− :: Condition relations ('Grouped bys) params -- ^ having condition
791+ :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition
562− -> TableExpression schema params relations ('Grouped bys)
792+ -> TableExpression outer commons ('Grouped bys) schemas params from
563− -> TableExpression schema params relations ('Grouped bys)
793+ -> TableExpression outer commons ('Grouped bys) schemas params from
564having hv rels = rels
794having hv rels = rels
565 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }
795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }
566
796
567−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an
797+instance OrderBy TableExpression where
568−-- ordering to the right of the `orderByClause`.
798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}
569−orderBy
570− :: [SortExpression relations grouping params] -- ^ sort expressions
571− -> TableExpression schema params relations grouping
572− -> TableExpression schema params relations grouping
573−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}
574
799
575-- | 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
576-- `limitClause`.
801-- `limitClause`.
577limit
802limit
578 :: Word64 -- ^ limit parameter
803 :: Word64 -- ^ limit parameter
579− -> TableExpression schema params relations grouping
804+ -> TableExpression outer commons grp schemas params from
580− -> TableExpression schema params relations grouping
805+ -> TableExpression outer commons grp schemas params from
581limit lim rels = rels {limitClause = lim : limitClause rels}
806limit lim rels = rels {limitClause = lim : limitClause rels}
582
807
583-- | 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
584-- `offsetClause`.
809-- `offsetClause`.
585offset
810offset
586 :: Word64 -- ^ offset parameter
811 :: Word64 -- ^ offset parameter
587− -> TableExpression schema params relations grouping
812+ -> TableExpression outer commons grp schemas params from
588− -> TableExpression schema params relations grouping
813+ -> TableExpression outer commons grp schemas params from
589offset off rels = rels {offsetClause = off : offsetClause rels}
814offset off rels = rels {offsetClause = off : offsetClause rels}
590
815
591{-----------------------------------------
816{-----------------------------------------
@@ -596,51 +821,76 @@ FROM clauses
596A `FromClause` can be a table name, or a derived table such
821A `FromClause` can be a table name, or a derived table such
597as a subquery, a @JOIN@ construct, or complex combinations of these.
822as a subquery, a @JOIN@ construct, or complex combinations of these.
598-}
823-}
599−newtype FromClause schema params relations
824+newtype FromClause outer commons schemas params from
600 = UnsafeFromClause { renderFromClause :: ByteString }
825 = UnsafeFromClause { renderFromClause :: ByteString }
601 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
602
829
603−-- | A real `table` is a table from the schema.
830+-- | A real `table` is a table from the database.
604table
831table
605− :: Aliased (Table schema) table
832+ :: (Has sch schemas schema, Has tab schema ('Table table))
606− -> FromClause schema params '[table]
833+ => Aliased (QualifiedAlias sch) (alias ::: tab)
607−table = UnsafeFromClause . renderAliasedAs renderTable
834+ -> FromClause outer commons schemas params '[alias ::: TableToRow table]
835+table (tab `As` alias) = UnsafeFromClause $
836+ renderSQL tab <+> "AS" <+> renderSQL alias
608
837
609-- | `subquery` derives a table from a `Query`.
838-- | `subquery` derives a table from a `Query`.
610subquery
839subquery
611− :: Aliased (Query schema params) table
840+ :: Aliased (Query outer commons schemas params) query
612− -> FromClause schema params '[table]
841+ -> FromClause outer commons schemas params '[query]
613−subquery = UnsafeFromClause . renderAliasedAs (parenthesized . renderQuery)
842+subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)
614−
843+
615−{- | @left & crossJoin right@. For every possible combination of rows from
844+-- | `view` derives a table from a `View`.
616− @left@ and @right@ (i.e., a Cartesian product), the joined table will contain
845+view
617− a row consisting of all columns in @left@ followed by all columns in @right@.
846+ :: (Has sch schemas schema, Has vw schema ('View view))
618− If the tables have @n@ and @m@ rows respectively, the joined table will
847+ => Aliased (QualifiedAlias sch) (alias ::: vw)
619− have @n * m@ rows.
848+ -> FromClause outer commons schemas params '[alias ::: view]
849+view (vw `As` alias) = UnsafeFromClause $
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
859+
860+instance Additional (FromClause outer commons schemas params) where
861+ also right left = UnsafeFromClause $
862+ renderSQL left <> ", " <> renderSQL right
863+
864+{- |
865+@left & crossJoin right@. For every possible combination of rows from
866+@left@ and @right@ (i.e., a Cartesian product), the joined table will contain
867+a row consisting of all columns in @left@ followed by all columns in @right@.
868+If the tables have @n@ and @m@ rows respectively, the joined table will
869+have @n * m@ rows.
620-}
870-}
621crossJoin
871crossJoin
622− :: FromClause schema params right
872+ :: FromClause outer commons schemas params right
623 -- ^ right
873 -- ^ right
624− -> FromClause schema params left
874+ -> FromClause outer commons schemas params left
625 -- ^ left
875 -- ^ left
626− -> FromClause schema params (Join left right)
876+ -> FromClause outer commons schemas params (Join left right)
627crossJoin right left = UnsafeFromClause $
877crossJoin right left = UnsafeFromClause $
628− renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right
878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right
629
879
630{- | @left & innerJoin right on@. The joined table is filtered by
880{- | @left & innerJoin right on@. The joined table is filtered by
631the @on@ condition.
881the @on@ condition.
632-}
882-}
633innerJoin
883innerJoin
634− :: FromClause schema params right
884+ :: FromClause outer commons schemas params right
635 -- ^ right
885 -- ^ right
636− -> Condition (Join left right) 'Ungrouped params
886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
637 -- ^ @on@ condition
887 -- ^ @on@ condition
638− -> FromClause schema params left
888+ -> FromClause outer commons schemas params left
639 -- ^ left
889 -- ^ left
640− -> FromClause schema params (Join left right)
890+ -> FromClause outer commons schemas params (Join left right)
641innerJoin right on left = UnsafeFromClause $
891innerJoin right on left = UnsafeFromClause $
642− renderFromClause left <+> "INNER JOIN" <+> renderFromClause right
892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right
643− <+> "ON" <+> renderExpression on
893+ <+> "ON" <+> renderSQL on
644
894
645{- | @left & leftOuterJoin right on@. First, an inner join is performed.
895{- | @left & leftOuterJoin right on@. First, an inner join is performed.
646 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
@@ -648,16 +898,16 @@ innerJoin right on left = UnsafeFromClause $
648 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@.
649-}
899-}
650leftOuterJoin
900leftOuterJoin
651− :: FromClause schema params right
901+ :: FromClause outer commons schemas params right
652 -- ^ right
902 -- ^ right
653− -> Condition (Join left right) 'Ungrouped params
903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
654 -- ^ @on@ condition
904 -- ^ @on@ condition
655− -> FromClause schema params left
905+ -> FromClause outer commons schemas params left
656 -- ^ left
906 -- ^ left
657− -> FromClause schema params (Join left (NullifyRelations right))
907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))
658leftOuterJoin right on left = UnsafeFromClause $
908leftOuterJoin right on left = UnsafeFromClause $
659− renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right
909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right
660− <+> "ON" <+> renderExpression on
910+ <+> "ON" <+> renderSQL on
661
911
662{- | @left & rightOuterJoin right on@. First, an inner join is performed.
912{- | @left & rightOuterJoin right on@. First, an inner join is performed.
663 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
@@ -666,16 +916,16 @@ leftOuterJoin right on left = UnsafeFromClause $
666 have a row for each row in @right@.
916 have a row for each row in @right@.
667-}
917-}
668rightOuterJoin
918rightOuterJoin
669− :: FromClause schema params right
919+ :: FromClause outer commons schemas params right
670 -- ^ right
920 -- ^ right
671− -> Condition (Join left right) 'Ungrouped params
921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
672 -- ^ @on@ condition
922 -- ^ @on@ condition
673− -> FromClause schema params left
923+ -> FromClause outer commons schemas params left
674 -- ^ left
924 -- ^ left
675− -> FromClause schema params (Join (NullifyRelations left) right)
925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)
676rightOuterJoin right on left = UnsafeFromClause $
926rightOuterJoin right on left = UnsafeFromClause $
677− renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right
927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right
678− <+> "ON" <+> renderExpression on
928+ <+> "ON" <+> renderSQL on
679
929
680{- | @left & fullOuterJoin right on@. First, an inner join is performed.
930{- | @left & fullOuterJoin right on@. First, an inner join is performed.
681 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
@@ -685,47 +935,56 @@ rightOuterJoin right on left = UnsafeFromClause $
685 is added.
935 is added.
686-}
936-}
687fullOuterJoin
937fullOuterJoin
688− :: FromClause schema params right
938+ :: FromClause outer commons schemas params right
689 -- ^ right
939 -- ^ right
690− -> Condition (Join left right) 'Ungrouped params
940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)
691 -- ^ @on@ condition
941 -- ^ @on@ condition
692− -> FromClause schema params left
942+ -> FromClause outer commons schemas params left
693 -- ^ left
943 -- ^ left
694− -> FromClause schema params
944+ -> FromClause outer commons schemas params
695− (Join (NullifyRelations left) (NullifyRelations right))
945+ (Join (NullifyFrom left) (NullifyFrom right))
696fullOuterJoin right on left = UnsafeFromClause $
946fullOuterJoin right on left = UnsafeFromClause $
697− renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right
947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right
698− <+> "ON" <+> renderExpression on
948+ <+> "ON" <+> renderSQL on
699
949
700{-----------------------------------------
950{-----------------------------------------
701Grouping
951Grouping
702-----------------------------------------}
952-----------------------------------------}
703
953
704−-- | `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
705-- 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
706-- in all the columns listed. @By \#col@ will reference an unambiguous
956-- in all the columns listed. @By \#col@ will reference an unambiguous
707-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
708-- qualified column @tab.col@.
958-- qualified column @tab.col@.
709data By
959data By
710− (relations :: RelationsType)
960+ (from :: FromType)
711 (by :: (Symbol,Symbol)) where
961 (by :: (Symbol,Symbol)) where
712− By
962+ By1
713− :: (HasUnique relation relations columns, Has column columns ty)
963+ :: (HasUnique table from columns, Has column columns ty)
714 => Alias column
964 => Alias column
715− -> By relations '(relation, column)
965+ -> By from '(table, column)
716 By2
966 By2
717− :: (Has relation relations columns, Has column columns ty)
967+ :: (Has table from columns, Has column columns ty)
718− => (Alias relation, Alias column)
968+ => Alias table
719− -> By relations '(relation, column)
969+ -> Alias column
720−deriving instance Show (By relations by)
970+ -> By from '(table, column)
721−deriving instance Eq (By relations by)
971+deriving instance Show (By from by)
722−deriving instance Ord (By relations by)
972+deriving instance Eq (By from by)
723−
973+deriving instance Ord (By from by)
724−-- | Renders a `By`.
974+instance RenderSQL (By from by) where
725−renderBy :: By relations by -> ByteString
975+ renderSQL = \case
726−renderBy = \case
976+ By1 column -> renderSQL column
727− By column -> renderAlias column
977+ By2 rel column -> renderSQL rel <> "." <> renderSQL column
728− By2 (rel, column) -> renderAlias rel <> "." <> renderAlias 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
729
988
730-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.
989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.
731-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
@@ -733,82 +992,107 @@ renderBy = \case
733-- done on @NoGroups@ while all output `Expression`s must be aggregated
992-- done on @NoGroups@ while all output `Expression`s must be aggregated
734-- in @Group Nil@. In general, all output `Expression`s in the
993-- in @Group Nil@. In general, all output `Expression`s in the
735-- complement of @bys@ must be aggregated in @Group bys@.
994-- complement of @bys@ must be aggregated in @Group bys@.
736−data GroupByClause relations grouping where
995+newtype GroupByClause grp from = UnsafeGroupByClause
737− NoGroups :: GroupByClause relations 'Ungrouped
996+ { renderGroupByClause :: ByteString }
738− Group
997+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
739− :: SListI bys
998+instance RenderSQL (GroupByClause grp from) where
740− => NP (By relations) bys
999+ renderSQL = renderGroupByClause
741− -> GroupByClause relations ('Grouped bys)
1000+noGroups :: GroupByClause 'Ungrouped from
742−
1001+noGroups = UnsafeGroupByClause ""
743−-- | Renders a `GroupByClause`.
1002+group
744−renderGroupByClause :: GroupByClause relations grouping -> ByteString
1003+ :: SListI bys
745−renderGroupByClause = \case
1004+ => NP (By from) bys
746− NoGroups -> ""
1005+ -> GroupByClause ('Grouped bys) from
747− Group Nil -> ""
1006+group bys = UnsafeGroupByClause $ case bys of
748− Group bys -> " GROUP BY" <+> renderCommaSeparated renderBy bys
1007+ Nil -> ""
1008+ bys' -> " GROUP BY" <+> renderCommaSeparated renderSQL bys'
749
1009
750-- | 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.
751-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
1011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
752-- `TableExpression` must use `Having` whose conditions are combined with
1012-- `TableExpression` must use `Having` whose conditions are combined with
753-- `.&&`.
1013-- `.&&`.
754−data HavingClause relations grouping params where
1014+data HavingClause outer commons grp schemas params from where
755− NoHaving :: HavingClause relations 'Ungrouped params
1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from
756 Having
1016 Having
757− :: [Condition relations ('Grouped bys) params]
1017+ :: [Condition outer commons ('Grouped bys) schemas params from]
758− -> HavingClause relations ('Grouped bys) params
1018+ -> HavingClause outer commons ('Grouped bys) schemas params from
759−deriving instance Show (HavingClause relations grouping params)
1019+deriving instance Show (HavingClause outer commons grp schemas params from)
760−deriving instance Eq (HavingClause relations grouping params)
1020+deriving instance Eq (HavingClause outer commons grp schemas params from)
761−deriving instance Ord (HavingClause relations grouping params)
1021+deriving instance Ord (HavingClause outer commons grp schemas params from)
762
1022
763-- | Render a `HavingClause`.
1023-- | Render a `HavingClause`.
764−renderHavingClause :: HavingClause relations grouping params -> ByteString
1024+instance RenderSQL (HavingClause outer commons grp schemas params from) where
765−renderHavingClause = \case
1025+ renderSQL = \case
766− NoHaving -> ""
1026+ NoHaving -> ""
767− Having [] -> ""
1027+ Having [] -> ""
768− Having conditions ->
1028+ Having conditions ->
769− " HAVING" <+> commaSeparated (renderExpression <$> conditions)
1029+ " HAVING" <+> commaSeparated (renderSQL <$> conditions)
770−
1030+
771−{-----------------------------------------
1031+-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.
772−Sorting
1032+data CommonTableExpression statement
773−-----------------------------------------}
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
774
1074
775−-- | `SortExpression`s are used by `sortBy` to optionally sort the results
1075+{- |
776−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result
1076+>>> import Data.Monoid (Sum (..))
777−-- column to ascending or descending. Ascending order puts smaller values
1077+>>> import Data.Int (Int64)
778−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,
1078+>>> :{
779−-- descending order is determined with the `.>` operator. `AscNullsFirst`,
1079+ let
780−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to
1080+ query :: Query_ schema () (Sum Int64)
781−-- determine whether nulls appear before or after non-null values in the sort
1081+ query = withRecursive
782−-- ordering of a `Null` result column.
1082+ ( values_ ((1 & astype int) `as` #n)
783−data SortExpression relations grouping params where
1083+ `unionAll`
784− Asc
1084+ select_ ((#n + 1) `as` #n)
785− :: Expression relations grouping params ('NotNull ty)
1085+ (from (common #t) & where_ (#n .< 100)) `as` #t )
786− -> SortExpression relations grouping params
1086+ ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))
787− Desc
1087+ in printSQL query
788− :: Expression relations grouping params ('NotNull ty)
1088+:}
789− -> SortExpression 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"
790− AscNullsFirst
1090+-}
791− :: Expression relations grouping params ('Null ty)
1091+withRecursive
792− -> SortExpression relations grouping params
1092+ :: Aliased (Query outer (recursive ': commons) schemas params) recursive
793− AscNullsLast
1093+ -> Query outer (recursive ': commons) schemas params row
794− :: Expression relations grouping params ('Null ty)
1094+ -> Query outer commons schemas params row
795− -> SortExpression relations grouping params
1095+withRecursive (recursive `As` cte) query = UnsafeQuery $
796− DescNullsFirst
1096+ "WITH RECURSIVE" <+> renderSQL cte
797− :: Expression relations grouping params ('Null ty)
1097+ <+> "AS" <+> parenthesized (renderSQL recursive)
798− -> SortExpression relations grouping params
1098+ <+> renderSQL query
799− DescNullsLast
800− :: Expression relations grouping params ('Null ty)
801− -> SortExpression relations grouping params
802−deriving instance Show (SortExpression relations grouping params)
803−
804−-- | Render a `SortExpression`.
805−renderSortExpression :: SortExpression relations grouping params -> ByteString
806−renderSortExpression = \case
807− Asc expression -> renderExpression expression <+> "ASC"
808− Desc expression -> renderExpression expression <+> "DESC"
809− AscNullsFirst expression -> renderExpression expression
810− <+> "ASC NULLS FIRST"
811− DescNullsFirst expression -> renderExpression expression
812− <+> "DESC NULLS FIRST"
813− AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"
814− DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"
squeal-postgresql/src/Squeal/PostgreSQL/Render.hs+76−6
@@ -9,7 +9,11 @@ Rendering helper functions.
9-}
9-}
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12− MagicHash
12+ AllowAmbiguousTypes
13+ , ConstraintKinds
14+ , FlexibleContexts
15+ , LambdaCase
16+ , MagicHash
13 , OverloadedStrings
17 , OverloadedStrings
14 , PolyKinds
18 , PolyKinds
15 , RankNTypes
19 , RankNTypes
@@ -19,35 +23,67 @@ Rendering helper functions.
19
23
20module Squeal.PostgreSQL.Render
24module Squeal.PostgreSQL.Render
21 ( -- * Render
25 ( -- * Render
22− parenthesized
26+ RenderSQL (..)
27+ , printSQL
28+ , escape
29+ , parenthesized
30+ , bracketed
23 , (<+>)
31 , (<+>)
24 , commaSeparated
32 , commaSeparated
33+ , doubleQuoted
34+ , singleQuotedText
35+ , singleQuotedUtf8
25 , renderCommaSeparated
36 , renderCommaSeparated
37+ , renderCommaSeparatedConstraint
26 , renderCommaSeparatedMaybe
38 , renderCommaSeparatedMaybe
27 , renderNat
39 , renderNat
40+ , renderSymbol
28 ) where
41 ) where
29
42
43+import Control.Monad.IO.Class (MonadIO (..))
30import Data.ByteString (ByteString)
44import Data.ByteString (ByteString)
31−import Data.Maybe
45+import Data.Maybe (catMaybes)
32import Data.Monoid ((<>))
46import Data.Monoid ((<>))
47+import Data.Text (Text)
33import Generics.SOP
48import Generics.SOP
34import GHC.Exts
49import GHC.Exts
35−import GHC.TypeLits
50+import GHC.TypeLits hiding (Text)
36
51
52+import qualified Data.Text as Text
53+import qualified Data.Text.Encoding as Text
37import qualified Data.ByteString as ByteString
54import qualified Data.ByteString as ByteString
55+import qualified Data.ByteString.Char8 as Char8
38
56
39-- | Parenthesize a `ByteString`.
57-- | Parenthesize a `ByteString`.
40parenthesized :: ByteString -> ByteString
58parenthesized :: ByteString -> ByteString
41parenthesized str = "(" <> str <> ")"
59parenthesized str = "(" <> str <> ")"
42
60
61+-- | Square bracket a `ByteString`
62+bracketed :: ByteString -> ByteString
63+bracketed str = "[" <> str <> "]"
64+
43-- | Concatenate two `ByteString`s with a space between.
65-- | Concatenate two `ByteString`s with a space between.
44(<+>) :: ByteString -> ByteString -> ByteString
66(<+>) :: ByteString -> ByteString -> ByteString
67+infixr 7 <+>
45str1 <+> str2 = str1 <> " " <> str2
68str1 <+> str2 = str1 <> " " <> str2
46
69
47-- | Comma separate a list of `ByteString`s.
70-- | Comma separate a list of `ByteString`s.
48commaSeparated :: [ByteString] -> ByteString
71commaSeparated :: [ByteString] -> ByteString
49commaSeparated = ByteString.intercalate ", "
72commaSeparated = ByteString.intercalate ", "
50
73
74+-- | Add double quotes around a `ByteString`.
75+doubleQuoted :: ByteString -> ByteString
76+doubleQuoted str = "\"" <> str <> "\""
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+
51-- | Comma separate the renderings of a heterogeneous list.
87-- | Comma separate the renderings of a heterogeneous list.
52renderCommaSeparated
88renderCommaSeparated
53 :: SListI xs
89 :: SListI xs
@@ -58,6 +94,16 @@ renderCommaSeparated render
58 . hcollapse
94 . hcollapse
59 . hmap (K . render)
95 . hmap (K . render)
60
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+
61-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping
107-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping
62-- `Nothing`s.
108-- `Nothing`s.
63renderCommaSeparatedMaybe
109renderCommaSeparatedMaybe
@@ -71,5 +117,29 @@ renderCommaSeparatedMaybe render
71 . hmap (K . render)
117 . hmap (K . render)
72
118
73-- | Render a promoted `Nat`.
119-- | Render a promoted `Nat`.
74−renderNat :: KnownNat n => proxy n -> ByteString
120+renderNat :: forall n. KnownNat n => ByteString
75−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))
126+
127+-- | A class for rendering SQL
128+class RenderSQL sql where renderSQL :: sql -> ByteString
129+
130+-- | Print SQL.
131+printSQL :: (RenderSQL sql, MonadIO io) => sql -> io ()
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+375−348
@@ -1,118 +1,118 @@
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−A type-level DSL for kinds of PostgreSQL types, constraints, and aliases.
8+`Squeal.PostgreSQL.Schema` provides a type-level DSL for kinds of Postgres types,
9+tables, schema, constraints, aliases, enumerated labels, and groupings.
10+It also defines useful type families to operate on these. Finally,
11+it defines an embedding of Haskell types into Postgres types.
9-}
12-}
10−
11{-# LANGUAGE
13{-# LANGUAGE
12 AllowAmbiguousTypes
14 AllowAmbiguousTypes
13 , ConstraintKinds
15 , ConstraintKinds
14− , DataKinds
15 , DeriveAnyClass
16 , DeriveAnyClass
16− , DeriveDataTypeable
17 , DeriveGeneric
17 , DeriveGeneric
18 , FlexibleContexts
18 , FlexibleContexts
19 , FlexibleInstances
19 , FlexibleInstances
20 , FunctionalDependencies
20 , FunctionalDependencies
21 , GADTs
21 , GADTs
22− , MagicHash
22+ , LambdaCase
23− , MultiParamTypeClasses
24 , OverloadedStrings
23 , OverloadedStrings
25− , PolyKinds
24+ , QuantifiedConstraints
26 , RankNTypes
25 , RankNTypes
27 , ScopedTypeVariables
26 , ScopedTypeVariables
28 , StandaloneDeriving
27 , StandaloneDeriving
29 , TypeApplications
28 , TypeApplications
30− , TypeFamilies
29+ , TypeFamilyDependencies
31 , TypeInType
30 , TypeInType
32 , TypeOperators
31 , TypeOperators
33 , UndecidableInstances
32 , UndecidableInstances
33+ , UndecidableSuperClasses
34#-}
34#-}
35
35
36module Squeal.PostgreSQL.Schema
36module Squeal.PostgreSQL.Schema
37− ( -- * Types
37+ ( -- * Postgres Types
38 PGType (..)
38 PGType (..)
39− , HasOid (..)
40 , NullityType (..)
39 , NullityType (..)
40+ , RowType
41+ , FromType
42+ -- * Schema Types
41 , ColumnType
43 , ColumnType
42 , ColumnsType
44 , ColumnsType
43− , RelationType
44− , NilRelation
45− , RelationsType
46 , TableType
45 , TableType
47− , TablesType
46+ , SchemumType (..)
48− , NilTables
47+ , IndexType (..)
49− -- * Grouping
48+ , FunctionType
50− , Grouping (..)
49+ , OperatorType (..)
51− , GroupedBy
50+ , ReturnsType (..)
51+ , SchemaType
52+ , SchemasType
53+ , Public
52 -- * Constraints
54 -- * Constraints
53 , (:=>)
55 , (:=>)
54 , ColumnConstraint (..)
56 , ColumnConstraint (..)
55 , TableConstraint (..)
57 , TableConstraint (..)
56 , TableConstraints
58 , TableConstraints
57− , NilTableConstraints
59+ , Uniquely
58− -- * Aliases
60+ -- * Enumerated Labels
59− , (:::)
61+ , IsPGlabel (..)
60− , Alias (Alias)
62+ , PGlabel (..)
61− , renderAlias
63+ -- * Data Definitions
62− , Aliased (As)
63− , renderAliasedAs
64− , AliasesOf
65− , Has
66− , HasUnique
67− , IsLabel (..)
68− , IsQualified (..)
69− -- * Type Families
70− , Join
71 , Create
64 , Create
65+ , CreateIfNotExists
66+ , CreateOrReplace
72 , Drop
67 , Drop
68+ , DropSchemum
69+ , DropIfExists
70+ , DropSchemumIfExists
73 , Alter
71 , Alter
72+ , AlterIfExists
74 , Rename
73 , Rename
75− , Elem
74+ , RenameIfExists
76− , In
75+ , ConstraintInvolves
76+ , DropIfConstraintsInvolve
77+ , IsNotElem
78+ , AllUnique
79+ -- * Type Classifications
77 , PGNum
80 , PGNum
78 , PGIntegral
81 , PGIntegral
79 , PGFloating
82 , PGFloating
80 , PGTypeOf
83 , PGTypeOf
81− , SameTypes
84+ , PGJsonType
85+ , PGJsonKey
86+ , SamePGType
82 , AllNotNull
87 , AllNotNull
83 , NotAllNull
88 , NotAllNull
89+ -- * Nullifications
84 , NullifyType
90 , NullifyType
85− , NullifyRelation
91+ , NullifyRow
86− , NullifyRelations
92+ , NullifyFrom
87− , ColumnsToRelation
93+ -- * Table Conversions
88− , RelationToColumns
89 , TableToColumns
94 , TableToColumns
90− , TablesToRelations
95+ , ColumnsToRow
91− , RelationsToTables
96+ , TableToRow
92− , ConstraintInvolves
93− , DropIfConstraintsInvolve
94− -- * Generics
95− , SameField
96− , SameFields
97 ) where
97 ) where
98
98
99−import Control.DeepSeq
99+import Control.Category
100−import Data.ByteString
100+import Data.Kind
101−import Data.Monoid
101+import Data.Monoid hiding (All)
102−import Data.String
103−import Data.Word
104import Data.Type.Bool
102import Data.Type.Bool
105−import Generics.SOP (AllZip)
103+import Generics.SOP
106−import GHC.Generics (Generic)
107−import GHC.Exts
108−import GHC.OverloadedLabels
109import GHC.TypeLits
104import GHC.TypeLits
105+import Prelude hiding (id, (.))
106+
107+import Squeal.PostgreSQL.Alias
108+import Squeal.PostgreSQL.List
109+import Squeal.PostgreSQL.Render
110
110
111−import qualified Generics.SOP.Type.Metadata as Type
111+-- $setup
112+-- >>> import Squeal.PostgreSQL
112
113
113-- | `PGType` is the promoted datakind of PostgreSQL types.
114-- | `PGType` is the promoted datakind of PostgreSQL types.
114--
115--
115−-- >>> import Squeal.PostgreSQL.Schema
116-- >>> :kind 'PGbool
116-- >>> :kind 'PGbool
117-- 'PGbool :: PGType
117-- 'PGbool :: PGType
118data PGType
118data PGType
@@ -123,6 +123,7 @@ data PGType
123 | PGnumeric -- ^ arbitrary precision numeric type
123 | PGnumeric -- ^ arbitrary precision numeric type
124 | PGfloat4 -- ^ single precision floating-point number (4 bytes)
124 | PGfloat4 -- ^ single precision floating-point number (4 bytes)
125 | PGfloat8 -- ^ double precision floating-point number (8 bytes)
125 | PGfloat8 -- ^ double precision floating-point number (8 bytes)
126+ | PGmoney -- ^ currency amount
126 | PGchar Nat -- ^ fixed-length character string
127 | PGchar Nat -- ^ fixed-length character string
127 | PGvarchar Nat -- ^ variable-length character string
128 | PGvarchar Nat -- ^ variable-length character string
128 | PGtext -- ^ variable-length character string
129 | PGtext -- ^ variable-length character string
@@ -137,38 +138,16 @@ data PGType
137 | PGinet -- ^ IPv4 or IPv6 host address
138 | PGinet -- ^ IPv4 or IPv6 host address
138 | PGjson -- ^ textual JSON data
139 | PGjson -- ^ textual JSON data
139 | PGjsonb -- ^ binary JSON data, decomposed
140 | PGjsonb -- ^ binary JSON data, decomposed
140− | PGvararray PGType -- ^ variable length array
141+ | PGvararray NullityType -- ^ variable length array
141− | PGfixarray Nat PGType -- ^ fixed length array
142+ | PGfixarray [Nat] NullityType -- ^ fixed length array
143+ | PGenum [Symbol] -- ^ enumerated (enum) types are data types that comprise a static, ordered set of values.
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).
142 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types
149 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types
143
150
144−-- | The object identifier of a `PGType`.
145−--
146−-- >>> :set -XTypeApplications
147−-- >>> oid @'PGbool
148−-- 16
149−class HasOid (ty :: PGType) where oid :: Word32
150−instance HasOid 'PGbool where oid = 16
151−instance HasOid 'PGint2 where oid = 21
152−instance HasOid 'PGint4 where oid = 23
153−instance HasOid 'PGint8 where oid = 20
154−instance HasOid 'PGnumeric where oid = 1700
155−instance HasOid 'PGfloat4 where oid = 700
156−instance HasOid 'PGfloat8 where oid = 701
157−instance HasOid ('PGchar n) where oid = 18
158−instance HasOid ('PGvarchar n) where oid = 1043
159−instance HasOid 'PGtext where oid = 25
160−instance HasOid 'PGbytea where oid = 17
161−instance HasOid 'PGtimestamp where oid = 1114
162−instance HasOid 'PGtimestamptz where oid = 1184
163−instance HasOid 'PGdate where oid = 1082
164−instance HasOid 'PGtime where oid = 1083
165−instance HasOid 'PGtimetz where oid = 1266
166−instance HasOid 'PGinterval where oid = 1186
167−instance HasOid 'PGuuid where oid = 2950
168−instance HasOid 'PGinet where oid = 869
169−instance HasOid 'PGjson where oid = 114
170−instance HasOid 'PGjsonb where oid = 3802
171−
172-- | `NullityType` encodes the potential presence or definite absence of a
151-- | `NullityType` encodes the potential presence or definite absence of a
173-- @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.
174--
153--
@@ -187,14 +166,6 @@ data NullityType
187type (:=>) constraint ty = '(constraint,ty)
166type (:=>) constraint ty = '(constraint,ty)
188infixr 7 :=>
167infixr 7 :=>
189
168
190−-- | The alias operator `:::` is like a promoted version of `As`,
191−-- a type level pair between
192−-- an alias and some type, like a column alias and either a `ColumnType` or
193−-- `NullityType` or a table alias and either a `TableType` or a `RelationType`
194−-- or a constraint alias and a `TableConstraint`.
195−type (:::) (alias :: Symbol) ty = '(alias,ty)
196−infixr 6 :::
197−
198-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.
169-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.
199-- A column can be assigned a default value.
170-- A column can be assigned a default value.
200-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also
171-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also
@@ -236,11 +207,23 @@ data TableConstraint
236 | PrimaryKey [Symbol]
207 | PrimaryKey [Symbol]
237 | ForeignKey [Symbol] Symbol [Symbol]
208 | ForeignKey [Symbol] Symbol [Symbol]
238
209
239−-- | 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+-}
240type TableConstraints = [(Symbol,TableConstraint)]
217type TableConstraints = [(Symbol,TableConstraint)]
241−-- | A monokinded empty `TableConstraints`.
218+
242−type family NilTableConstraints :: TableConstraints where
219+-- | A `ForeignKey` must reference columns that either are
243− NilTableConstraints = '[]
220+-- a `PrimaryKey` or form a `Unique` constraint.
221+type family Uniquely
222+ (key :: [Symbol])
223+ (constraints :: TableConstraints) :: Constraint where
224+ Uniquely key (uq ::: 'Unique key ': constraints) = ()
225+ Uniquely key (pk ::: 'PrimaryKey key ': constraints) = ()
226+ Uniquely key (_ ': constraints) = Uniquely key constraints
244
227
245-- | `TableType` encodes a row of constraints on a table as well as the types
228-- | `TableType` encodes a row of constraints on a table as well as the types
246-- of its columns.
229-- of its columns.
@@ -255,302 +238,233 @@ type family NilTableConstraints :: TableConstraints where
255-- :}
238-- :}
256type TableType = (TableConstraints,ColumnsType)
239type TableType = (TableConstraints,ColumnsType)
257
240
258−-- | `TablesType` is a row of `TableType`s, thought of as a union.
241+{- | A `RowType` is a row of `NullityType`. They correspond to Haskell
259−--
242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.
260−-- >>> :{
243+
261−-- type family Schema :: TablesType where
244+>>> :{
262−-- Schema =
245+type family PersonRow :: RowType where
263−-- '[ "users" :::
246+ PersonRow =
264−-- '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
247+ '[ "name" ::: 'NotNull 'PGtext
265−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4
248+ , "age" ::: 'NotNull 'PGint4
266−-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext
249+ , "dateOfBirth" ::: 'Null 'PGdate
267−-- , "vec" ::: 'NoDef :=> 'NotNull ('PGvararray 'PGint2)
250+ ]
268−-- ]
251+:}
269−-- , "emails" :::
252+-}
270−-- '[ "pk_emails" ::: 'PrimaryKey '["id"]
253+type RowType = [(Symbol,NullityType)]
271−-- , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
272−-- ] :=>
273−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4
274−-- , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
275−-- , "email" ::: 'NoDef :=> 'Null 'PGtext
276−-- ]
277−-- ]
278−-- :}
279−type TablesType = [(Symbol,TableType)]
280−-- | A monokinded empty `TablesType`.
281−type family NilTables :: TablesType where NilTables = '[]
282−
283−-- | `RelationType` is a row of `NullityType`
284−--
285−-- >>> :{
286−-- type family PersonRelation :: RelationType where
287−-- PersonRelation =
288−-- '[ "name" ::: 'NotNull 'PGtext
289−-- , "age" ::: 'NotNull 'PGint4
290−-- , "dateOfBirth" ::: 'Null 'PGdate
291−-- ]
292−-- :}
293−type RelationType = [(Symbol,NullityType)]
294−-- | A monokinded empty `RelationType`.
295−type family NilRelation :: RelationType where NilRelation = '[]
296−
297−-- | `RelationsType` is a row of `RelationType`s, thought of as a product.
298−type RelationsType = [(Symbol,RelationType)]
299−
300−-- | `ColumnsToRelation` removes column constraints.
301−type family ColumnsToRelation (columns :: ColumnsType) :: RelationType where
302− ColumnsToRelation '[] = '[]
303− ColumnsToRelation (column ::: constraint :=> ty ': columns) =
304− column ::: ty ': ColumnsToRelation columns
305
254
306−-- | `RelationToColumns` adds `'NoDef` column constraints.
255+{- | `FromType` is a row of `RowType`s. It can be thought of as
307−type family RelationToColumns (relation :: RelationType) :: ColumnsType where
256+a product, or horizontal gluing and is used in `Squeal.PostgreSQL.Query.FromClause`s
308− RelationToColumns '[] = '[]
257+and `Squeal.PostgreSQL.Query.TableExpression`s.
309− RelationToColumns (column ::: ty ': columns) =
258+-}
310− column ::: 'NoDef :=> ty ': RelationToColumns columns
259+type FromType = [(Symbol,RowType)]
260+
261+-- | `ColumnsToRow` removes column constraints.
262+type family ColumnsToRow (columns :: ColumnsType) :: RowType where
263+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': column5 ::: _ :=> ty5 ': columns) =
264+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': ColumnsToRow 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 '[] = '[]
311
276
312-- | `TableToColumns` removes table constraints.
277-- | `TableToColumns` removes table constraints.
313type family TableToColumns (table :: TableType) :: ColumnsType where
278type family TableToColumns (table :: TableType) :: ColumnsType where
314 TableToColumns (constraints :=> columns) = columns
279 TableToColumns (constraints :=> columns) = columns
315
280
316−-- | `TablesToRelations` removes both table and column constraints.
281+-- | Convert a table to a row type.
317−type family TablesToRelations (tables :: TablesType) :: RelationsType where
282+type family TableToRow (table :: TableType) :: RowType where
318− TablesToRelations '[] = '[]
283+ TableToRow tab = ColumnsToRow (TableToColumns tab)
319− TablesToRelations (alias ::: constraint :=> columns ': tables) =
284+
320− alias ::: ColumnsToRelation columns ': TablesToRelations tables
285+-- | Numeric Postgres types.
321−
286+type PGNum =
322−-- | `RelationsToTables` adds both trivial table and column constraints.
287+ '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]
323−type family RelationsToTables (tables :: RelationsType) :: TablesType where
288+
324− RelationsToTables '[] = '[]
289+-- | Floating Postgres types.
325− RelationsToTables (alias ::: columns ': relations) =
290+type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]
326− alias ::: '[] :=> RelationToColumns columns ': RelationsToTables relations
291+
327−
292+-- | Integral Postgres types.
328−-- | `Grouping` is an auxiliary namespace, created by
293+type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]
329−-- @GROUP BY@ clauses (`Squeal.PostgreSQL.Query.group`), and used
330−-- for typesafe aggregation
331−data Grouping
332− = Ungrouped -- ^ no aggregation permitted
333− | Grouped [(Symbol,Symbol)] -- ^ aggregation required for any column which is not grouped
334−
335−{- | A `GroupedBy` constraint indicates that a table qualified column is
336−a member of the auxiliary namespace created by @GROUP BY@ clauses and thus,
337−may be called in an output `Squeal.PostgreSQL.Expression.Expression` without aggregating.
338−-}
339−class (KnownSymbol relation, KnownSymbol column)
340− => GroupedBy relation column bys where
341−instance {-# OVERLAPPING #-} (KnownSymbol relation, KnownSymbol column)
342− => GroupedBy relation column ('(table,column) ': bys)
343−instance {-# OVERLAPPABLE #-}
344− ( KnownSymbol relation
345− , KnownSymbol column
346− , GroupedBy relation column bys
347− ) => GroupedBy relation column (tabcol ': bys)
348−
349−-- | `Alias`es are proxies for a type level string or `Symbol`
350−-- and have an `IsLabel` instance so that with @-XOverloadedLabels@
351−--
352−-- >>> :set -XOverloadedLabels
353−-- >>> #foobar :: Alias "foobar"
354−-- Alias
355−data Alias (alias :: Symbol) = Alias
356− deriving (Eq,Generic,Ord,Show,NFData)
357−instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where
358− fromLabel = Alias
359−
360−-- | >>> renderAlias #jimbob
361−-- "jimbob"
362−renderAlias :: KnownSymbol alias => Alias alias -> ByteString
363−renderAlias = fromString . symbolVal
364−
365−-- | The `As` operator is used to name an expression. `As` is like a demoted
366−-- version of `:::`.
367−--
368−-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)
369−-- As (Just "hello") Alias
370−data Aliased expression aliased where
371− As
372− :: KnownSymbol alias
373− => expression ty
374− -> Alias alias
375− -> Aliased expression (alias ::: ty)
376−deriving instance Show (expression ty)
377− => Show (Aliased expression (alias ::: ty))
378−deriving instance Eq (expression ty)
379− => Eq (Aliased expression (alias ::: ty))
380−deriving instance Ord (expression ty)
381− => Ord (Aliased expression (alias ::: ty))
382−
383−-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")
384−-- >>> renderAliasedAs renderMaybe (Just (3::Int) `As` #an_int)
385−-- "Just AS an_int"
386−renderAliasedAs
387− :: (forall ty. expression ty -> ByteString)
388− -> Aliased expression aliased
389− -> ByteString
390−renderAliasedAs render (expression `As` alias) =
391− render expression <> " AS " <> renderAlias alias
392−
393−-- | `AliasesOf` retains the AliasesOf in a row.
394−type family AliasesOf aliaseds where
395− AliasesOf '[] = '[]
396− AliasesOf (alias ::: ty ': tys) = alias ': AliasesOf tys
397−
398−-- | @HasUnique alias fields field@ is a constraint that proves that
399−-- @fields@ is a singleton of @alias ::: field@.
400−type HasUnique alias fields field = fields ~ '[alias ::: field]
401−
402−-- | @Has alias fields field@ is a constraint that proves that
403−-- @fields@ has a field of @alias ::: field@.
404−class KnownSymbol alias =>
405− Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)
406− | alias fields -> field where
407−instance {-# OVERLAPPING #-} KnownSymbol alias
408− => Has alias (alias ::: field ': fields) field
409−instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)
410− => Has alias (field' ': fields) field
411−
412−-- | Analagous to `IsLabel`, the constraint
413−-- `IsQualified` defines `!` for a column alias qualified
414−-- by a table alias.
415−class IsQualified table column expression where
416− (!) :: Alias table -> Alias column -> expression
417− infixl 9 !
418−instance IsQualified table column (Alias table, Alias column) where (!) = (,)
419−
420−-- | @Elem@ is a promoted `Data.List.elem`.
421−type family Elem x xs where
422− Elem x '[] = 'False
423− Elem x (x ': xs) = 'True
424− Elem x (_ ': xs) = Elem x xs
425−
426−-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.
427−type family In x xs :: Constraint where In x xs = Elem x xs ~ 'True
428−
429−-- | `PGNum` is a constraint on `PGType` whose
430−-- `Squeal.PostgreSQL.Expression.Expression`s have a `Num` constraint.
431−type PGNum ty =
432− In ty '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]
433−
434−-- | `PGFloating` is a constraint on `PGType` whose
435−-- `Squeal.PostgreSQL.Expression.Expression`s
436−-- have `Fractional` and `Floating` constraints.
437−type PGFloating ty = In ty '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]
438−
439−-- | `PGIntegral` is a constraint on `PGType` whose
440−-- `Squeal.PostgreSQL.Expression.Expression`s
441−-- have `Squeal.PostgreSQL.Expression.div_` and
442−-- `Squeal.PostgreSQL.Expression.mod_` functions.
443−type PGIntegral ty = In ty '[ 'PGint2, 'PGint4, 'PGint8]
444
294
445-- | `PGTypeOf` forgets about @NULL@ and any column constraints.
295-- | `PGTypeOf` forgets about @NULL@ and any column constraints.
446type family PGTypeOf (ty :: NullityType) :: PGType where
296type family PGTypeOf (ty :: NullityType) :: PGType where
447 PGTypeOf (nullity pg) = pg
297 PGTypeOf (nullity pg) = pg
448
298
449−-- | `SameTypes` is a constraint that proves two `ColumnsType`s have the same
299+-- | Equality constraint on the underlying `PGType` of two columns.
450−-- length and the same `ColumnType`s.
300+class SamePGType
451−type family SameTypes (columns0 :: ColumnsType) (columns1 :: ColumnsType)
301+ (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where
452− :: Constraint where
302+instance ty0 ~ ty1 => SamePGType
453− SameTypes '[] '[] = ()
303+ (alias0 ::: def0 :=> nullity0 ty0)
454− SameTypes (column0 ::: def0 :=> ty0 ': columns0) (column1 ::: def1 :=> ty1 ': columns1)
304+ (alias1 ::: def1 :=> nullity1 ty1)
455− = (ty0 ~ ty1, SameTypes columns0 columns1)
456
305
457-- | `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.
458type 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
459 AllNotNull '[] = ()
314 AllNotNull '[] = ()
460− AllNotNull (column ::: def :=> 'NotNull ty ': columns) = AllNotNull columns
461
315
462-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some
316-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some
463-- @NOT NULL@.
317-- @NOT NULL@.
464type family NotAllNull (columns :: ColumnsType) :: Constraint where
318type family NotAllNull (columns :: ColumnsType) :: Constraint where
465− NotAllNull (column ::: def :=> 'NotNull ty ': columns) = ()
319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
466− NotAllNull (column ::: def :=> 'Null ty ': columns) = NotAllNull columns
320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
467−
321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
468−-- | `NullifyType` is an idempotent that nullifies a `ColumnType`.
322+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
323+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()
324+ NotAllNull (_ ::: _ :=> 'NotNull _ ': _) = ()
325+ NotAllNull (_ ::: _ :=> 'Null _ ': columns) = NotAllNull columns
326+
327+-- | `NullifyType` is an idempotent that nullifies a `NullityType`.
469type family NullifyType (ty :: NullityType) :: NullityType where
328type family NullifyType (ty :: NullityType) :: NullityType where
470 NullifyType ('Null ty) = 'Null ty
329 NullifyType ('Null ty) = 'Null ty
471 NullifyType ('NotNull ty) = 'Null ty
330 NullifyType ('NotNull ty) = 'Null ty
472
331
473−-- | `NullifyRelation` is an idempotent that nullifies a `ColumnsType`.
332+-- | `NullifyRow` is an idempotent that nullifies a `RowType`.
474−type family NullifyRelation (columns :: RelationType) :: RelationType where
333+type family NullifyRow (columns :: RowType) :: RowType where
475− NullifyRelation '[] = '[]
334+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': columns) =
476− NullifyRelation (column ::: ty ': columns) =
335+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': column5 ::: NullifyType ty5 ': NullifyRow columns
477− column ::: NullifyType ty ': NullifyRelation columns
336+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': columns) =
478−
337+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': NullifyRow columns
479−-- | `NullifyRelations` is an idempotent that nullifies a `RelationsType`
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
344+ NullifyRow (column ::: ty ': columns) =
345+ column ::: NullifyType ty ': NullifyRow columns
346+ NullifyRow '[] = '[]
347+
348+-- | `NullifyFrom` is an idempotent that nullifies a `FromType`
480-- 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
481-- in a `Squeal.PostgreSQL.Query.FromClause`.
350-- in a `Squeal.PostgreSQL.Query.FromClause`.
482−type family NullifyRelations (tables :: RelationsType) :: RelationsType where
351+type family NullifyFrom (tables :: FromType) :: FromType where
483− NullifyRelations '[] = '[]
352+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': table5 ::: columns5 ': tables) =
484− 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
485− table ::: NullifyRelation columns ': NullifyRelations tables
354+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': tables) =
486−
355+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns4 ': NullifyFrom tables
487−-- | `Join` is simply promoted `++` and is used in @JOIN@s in
356+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': tables) =
488−-- `Squeal.PostgreSQL.Query.FromClause`s.
357+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': NullifyFrom tables
489−type family Join xs ys where
358+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': tables) =
490− Join '[] ys = ys
359+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': NullifyFrom tables
491− Join (x ': xs) ys = x ': Join xs ys
360+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': tables) =
361+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': NullifyFrom tables
362+ NullifyFrom (table ::: columns ': tables) =
363+ table ::: NullifyRow columns ': NullifyFrom tables
364+ NullifyFrom '[] = '[]
492
365
493-- | @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
494-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@
367-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@
495-- `Squeal.PostgreSQL.Definition.addColumn`.
368-- `Squeal.PostgreSQL.Definition.addColumn`.
496type family Create alias x xs where
369type family Create alias x xs where
497 Create alias x '[] = '[alias ::: x]
370 Create alias x '[] = '[alias ::: x]
371+ Create alias x (alias ::: y ': xs) = TypeError
372+ ('Text "Create: alias "
373+ ':<>: 'ShowType alias
374+ ':<>: 'Text "already exists")
498 Create alias y (x ': xs) = x ': Create alias y xs
375 Create alias y (x ': xs) = x ': Create alias y xs
499
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+
500-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@
394-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@
501-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements
395-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements
502-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.
396-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.
503type family Drop alias xs where
397type family Drop alias xs where
504− Drop alias ((alias ::: x) ': xs) = xs
398+ Drop alias '[] = TypeError
399+ ('Text "Drop: alias "
400+ ':<>: 'ShowType alias
401+ ':<>: 'Text " does not exist" )
402+ Drop alias (alias ::: x ': xs) = xs
505 Drop alias (x ': xs) = x ': Drop alias xs
403 Drop alias (x ': xs) = x ': Drop alias xs
506
404
507−-- | @Alter alias xs x@ replaces the type associated with an @alias@ in @xs@
405+type family DropSchemum alias sch xs where
508−-- with the type `x` and is used in `Squeal.PostgreSQL.Definition.alterTable`
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+
437+-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@
438+-- with the type @x@ and is used in `Squeal.PostgreSQL.Definition.alterTable`
509-- and `Squeal.PostgreSQL.Definition.alterColumn`.
439-- and `Squeal.PostgreSQL.Definition.alterColumn`.
510−type family Alter alias xs x where
440+type family Alter alias x xs where
511− Alter alias ((alias ::: x0) ': xs) x1 = (alias ::: x1) ': xs
441+ Alter alias x '[] = TypeError
512− Alter alias (x0 ': xs) x1 = x0 ': Alter alias xs x1
442+ ('Text "Alter: alias "
513−
443+ ':<>: 'ShowType alias
514−-- type family AddConstraint constraint ty where
444+ ':<>: 'Text " does not exist" )
515−-- AddConstraint constraint (constraints :=> ty)
445+ Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs
516−-- = AsSet (constraint ': constraints) :=> ty
446+ Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs
517−
447+
518−-- type family DeleteFromList (e :: elem) (list :: [elem]) where
448+type family AlterIfExists alias x xs where
519−-- DeleteFromList elem '[] = '[]
449+ AlterIfExists alias x '[] = '[]
520−-- DeleteFromList elem (x ': xs) =
450+ AlterIfExists alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs
521−-- If (Cmp elem x == 'EQ) xs (x ': DeleteFromList elem xs)
451+ AlterIfExists alias x1 (x0 ': xs) = x0 ': AlterIfExists alias x1 xs
522−
523−-- type family DropConstraint constraint ty where
524−-- DropConstraint constraint (constraints :=> ty)
525−-- = (AsSet (DeleteFromList constraint constraints)) :=> ty
526
452
527-- | @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@
528-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and
454-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and
529-- `Squeal.PostgreSQL.Definition.renameColumn`.
455-- `Squeal.PostgreSQL.Definition.renameColumn`.
530type 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" )
531 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs
461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs
532 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs
462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs
533
463
534−-- | A `SameField` constraint is an equality constraint on a
464+type family RenameIfExists alias0 alias1 xs where
535−-- `Generics.SOP.Type.Metadata.FieldInfo` and the column alias in a `:::` pair.
465+ RenameIfExists alias x '[] = '[]
536−class SameField
466+ RenameIfExists alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs
537− (fieldInfo :: Type.FieldInfo) (fieldty :: (Symbol,NullityType)) where
467+ RenameIfExists alias0 alias1 (x ': xs) = x ': RenameIfExists alias0 alias1 xs
538−instance field ~ column => SameField ('Type.FieldInfo field) (column ::: ty)
539−
540−-- | A `SameFields` constraint proves that a
541−-- `Generics.SOP.Type.Metadata.DatatypeInfo` of a record type has the same
542−-- field names as the column AliasesOf of a `ColumnsType`.
543−type family SameFields
544− (datatypeInfo :: Type.DatatypeInfo) (columns :: RelationType)
545− :: Constraint where
546− SameFields
547− ('Type.ADT _module _datatype '[ 'Type.Record _constructor fields])
548− columns
549− = AllZip SameField fields columns
550− SameFields
551− ('Type.Newtype _module _datatype ('Type.Record _constructor fields))
552− columns
553− = AllZip SameField fields columns
554
468
555-- | Check if a `TableConstraint` involves a column
469-- | Check if a `TableConstraint` involves a column
556type family ConstraintInvolves column constraint where
470type family ConstraintInvolves column constraint where
@@ -567,3 +481,116 @@ type family DropIfConstraintsInvolve column constraints where
567 = If (ConstraintInvolves column constraint)
481 = If (ConstraintInvolves column constraint)
568 (DropIfConstraintsInvolve column constraints)
482 (DropIfConstraintsInvolve column constraints)
569 (alias ::: constraint ': DropIfConstraintsInvolve column constraints)
483 (alias ::: constraint ': DropIfConstraintsInvolve column constraints)
484+
485+-- | A `SchemumType` is a user-defined type, either a `Table`,
486+-- `View` or `Typedef`.
487+data SchemumType
488+ = Table TableType
489+ | View RowType
490+ | Typedef PGType
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+
515+{- | The schema of a database consists of a list of aliased,
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+-}
537+type SchemaType = [(Symbol,SchemumType)]
538+
539+{- |
540+A database contains one or more named schemas, which in turn contain tables.
541+The same object name can be used in different schemas without conflict;
542+for example, both schema1 and myschema can contain tables named mytable.
543+Unlike databases, schemas are not rigidly separated:
544+a user can access objects in any of the schemas in the database they are connected to,
545+if they have privileges to do so.
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]
559+
560+-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas
561+-- the overloaded label, `fromLabel` is used for column references,
562+-- `label`s are used for enum terms. A `label` is called with
563+-- type application like `label @"beef"`.
564+class IsPGlabel (label :: Symbol) expr where label :: expr
565+instance label ~ label1
566+ => IsPGlabel label (PGlabel label1) where label = PGlabel
567+instance labels ~ '[label]
568+ => IsPGlabel label (NP PGlabel labels) where label = PGlabel :* Nil
569+-- | A `PGlabel` unit type with an `IsPGlabel` instance
570+data PGlabel (label :: Symbol) = PGlabel
571+instance KnownSymbol label => RenderSQL (PGlabel label) where
572+ renderSQL _ = "\'" <> renderSymbol @label <> "\'"
573+instance All KnownSymbol labels => RenderSQL (NP PGlabel labels) where
574+ renderSQL
575+ = commaSeparated
576+ . hcollapse
577+ . hcmap (Proxy @KnownSymbol) (K . renderSQL)
578+
579+-- | Is a type a valid JSON key?
580+type PGJsonKey = '[ 'PGint2, 'PGint4, 'PGtext ]
581+
582+-- | Is a type a valid JSON type?
583+type PGJsonType = '[ 'PGjson, 'PGjsonb ]
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+102−82
@@ -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
@@ -10,14 +10,9 @@ Squeal transaction control language.
10
10
11{-# LANGUAGE
11{-# LANGUAGE
12 DataKinds
12 DataKinds
13− , EmptyCase
14 , FlexibleContexts
13 , FlexibleContexts
15− , FlexibleInstances
16 , LambdaCase
14 , LambdaCase
17 , OverloadedStrings
15 , OverloadedStrings
18− , MultiParamTypeClasses
19− , ScopedTypeVariables
20− , TypeFamilies
21 , TypeInType
16 , TypeInType
22#-}
17#-}
23
18
@@ -25,89 +20,114 @@ module Squeal.PostgreSQL.Transaction
25 ( -- * Transaction
20 ( -- * Transaction
26 transactionally
21 transactionally
27 , transactionally_
22 , transactionally_
23+ , transactionallyRetry
24+ , ephemerally
25+ , ephemerally_
28 , begin
26 , begin
29 , commit
27 , commit
30 , rollback
28 , rollback
31− , transactionallySchema
32− , transactionallySchema_
33 -- * Transaction Mode
29 -- * Transaction Mode
34 , TransactionMode (..)
30 , TransactionMode (..)
35 , defaultMode
31 , defaultMode
36 , longRunningMode
32 , longRunningMode
37 , IsolationLevel (..)
33 , IsolationLevel (..)
38− , renderIsolationLevel
39 , AccessMode (..)
34 , AccessMode (..)
40− , renderAccessMode
41 , DeferrableMode (..)
35 , DeferrableMode (..)
42− , renderDeferrableMode
43 ) where
36 ) where
44
37
45−import Control.Exception.Lifted
38+import UnliftIO
46−import Control.Monad.Base
47−import Control.Monad.Trans.Control
48−import Data.ByteString
49−import Data.Monoid
50−import Generics.SOP
51−
52−import qualified Database.PostgreSQL.LibPQ as LibPQ
53
39
54import Squeal.PostgreSQL.Manipulation
40import Squeal.PostgreSQL.Manipulation
55import Squeal.PostgreSQL.Render
41import Squeal.PostgreSQL.Render
56import Squeal.PostgreSQL.PQ
42import Squeal.PostgreSQL.PQ
57−import Squeal.PostgreSQL.Schema
58
43
59−-- | 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+-}
60transactionally
50transactionally
61− :: (MonadBaseControl IO tx, MonadPQ schema tx)
51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)
62 => TransactionMode
52 => TransactionMode
63 -> tx x -- ^ run inside a transaction
53 -> tx x -- ^ run inside a transaction
64 -> tx x
54 -> tx x
65transactionally mode tx = mask $ \restore -> do
55transactionally mode tx = mask $ \restore -> do
66− _ <- begin mode
56+ manipulate_ $ begin mode
67− result <- restore tx `onException` rollback
57+ result <- restore tx `onException` (manipulate_ rollback)
68− _ <- commit
58+ manipulate_ commit
69 return result
59 return result
70
60
71−-- | Run a schema invariant computation `transactionally_` in `defaultMode`.
61+-- | Run a computation `transactionally_`, in `defaultMode`.
72transactionally_
62transactionally_
73− :: (MonadBaseControl IO tx, MonadPQ schema tx)
63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)
74 => tx x -- ^ run inside a transaction
64 => tx x -- ^ run inside a transaction
75 -> tx x
65 -> tx x
76transactionally_ = transactionally defaultMode
66transactionally_ = transactionally defaultMode
77
67
78−-- | @BEGIN@ a transaction.
68+{- |
79−begin :: MonadPQ schema tx => TransactionMode -> tx (K Result NilRelation)
69+`transactionallyRetry` a computation;
80−begin mode = manipulate . UnsafeManipulation $
70+
81− "BEGIN" <+> renderTransactionMode mode <> ";"
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)
79+ => TransactionMode
80+ -> tx x -- ^ run inside a transaction
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
82
112
83−-- | @COMMIT@ a schema invariant transaction.
113+{- | Run a computation `ephemerally` in `defaultMode`. -}
84−commit :: MonadPQ schema tx => tx (K Result NilRelation)
114+ephemerally_
85−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
86
123
87−-- | @ROLLBACK@ a schema invariant transaction.
124+-- | @COMMIT@ a transaction.
88−rollback :: MonadPQ schema tx => tx (K Result NilRelation)
125+commit :: Manipulation_ schemas () ()
89−rollback = manipulate $ UnsafeManipulation "ROLLBACK;"
126+commit = UnsafeManipulation "COMMIT"
90
127
91−-- | Run a schema changing computation `transactionallySchema`.
128+-- | @ROLLBACK@ a transaction.
92−transactionallySchema
129+rollback :: Manipulation_ schemas () ()
93− :: MonadBaseControl IO io
130+rollback = UnsafeManipulation "ROLLBACK"
94− => TransactionMode
95− -> PQ schema0 schema1 io x
96− -> PQ schema0 schema1 io x
97−transactionallySchema mode u = PQ $ \ conn -> mask $ \ restore -> do
98− _ <- liftBase . LibPQ.exec (unK conn) $
99− "BEGIN" <+> renderTransactionMode mode <> ";"
100− x <- restore (unPQ u conn)
101− `onException` (liftBase (LibPQ.exec (unK conn) "ROLLBACK"))
102− _ <- liftBase $ LibPQ.exec (unK conn) "COMMIT"
103− return x
104−
105−-- | Run a schema changing computation `transactionallySchema_` in `DefaultMode`.
106−transactionallySchema_
107− :: MonadBaseControl IO io
108− => PQ schema0 schema1 io x
109− -> PQ schema0 schema1 io x
110−transactionallySchema_ = transactionallySchema defaultMode
111
131
112-- | The available transaction characteristics are the transaction `IsolationLevel`,
132-- | The available transaction characteristics are the transaction `IsolationLevel`,
113-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.
133-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.
@@ -120,7 +140,7 @@ data TransactionMode = TransactionMode
120-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
140-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
121-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.
141-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.
122defaultMode :: TransactionMode
142defaultMode :: TransactionMode
123−defaultMode = TransactionMode Serializable ReadWrite NotDeferrable
143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable
124
144
125-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
145-- | `TransactionMode` with a `Serializable` `IsolationLevel`,
126-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.
146-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.
@@ -129,12 +149,12 @@ longRunningMode :: TransactionMode
129longRunningMode = TransactionMode Serializable ReadOnly Deferrable
149longRunningMode = TransactionMode Serializable ReadOnly Deferrable
130
150
131-- | Render a `TransactionMode`.
151-- | Render a `TransactionMode`.
132−renderTransactionMode :: TransactionMode -> ByteString
152+instance RenderSQL TransactionMode where
133−renderTransactionMode mode =
153+ renderSQL mode =
134− "ISOLATION LEVEL"
154+ "ISOLATION LEVEL"
135− <+> renderIsolationLevel (isolationLevel mode)
155+ <+> renderSQL (isolationLevel mode)
136− <+> renderAccessMode (accessMode mode)
156+ <+> renderSQL (accessMode mode)
137− <+> renderDeferrableMode (deferrableMode mode)
157+ <+> renderSQL (deferrableMode mode)
138
158
139-- | The SQL standard defines four levels of transaction isolation.
159-- | The SQL standard defines four levels of transaction isolation.
140-- 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
@@ -165,32 +185,32 @@ data IsolationLevel
165 = Serializable
185 = Serializable
166 -- ^ Dirty read is not possible.
186 -- ^ Dirty read is not possible.
167 -- Nonrepeatable read is not possible.
187 -- Nonrepeatable read is not possible.
168− -- Phantom read is not possible.
188+ -- Phantom read is not possible.
169 -- Serialization anomaly is not possible.
189 -- Serialization anomaly is not possible.
170 | RepeatableRead
190 | RepeatableRead
171 -- ^ Dirty read is not possible.
191 -- ^ Dirty read is not possible.
172 -- Nonrepeatable read is not possible.
192 -- Nonrepeatable read is not possible.
173− -- Phantom read is not possible.
193+ -- Phantom read is not possible.
174 -- Serialization anomaly is possible.
194 -- Serialization anomaly is possible.
175 | ReadCommitted
195 | ReadCommitted
176 -- ^ Dirty read is not possible.
196 -- ^ Dirty read is not possible.
177 -- Nonrepeatable read is possible.
197 -- Nonrepeatable read is possible.
178− -- Phantom read is possible.
198+ -- Phantom read is possible.
179 -- Serialization anomaly is possible.
199 -- Serialization anomaly is possible.
180 | ReadUncommitted
200 | ReadUncommitted
181 -- ^ Dirty read is not possible.
201 -- ^ Dirty read is not possible.
182 -- Nonrepeatable read is possible.
202 -- Nonrepeatable read is possible.
183− -- Phantom read is possible.
203+ -- Phantom read is possible.
184 -- Serialization anomaly is possible.
204 -- Serialization anomaly is possible.
185 deriving (Show, Eq)
205 deriving (Show, Eq)
186
206
187-- | Render an `IsolationLevel`.
207-- | Render an `IsolationLevel`.
188−renderIsolationLevel :: IsolationLevel -> ByteString
208+instance RenderSQL IsolationLevel where
189−renderIsolationLevel = \case
209+ renderSQL = \case
190− Serializable -> "SERIALIZABLE"
210+ Serializable -> "SERIALIZABLE"
191− ReadCommitted -> "READ COMMITTED"
211+ ReadCommitted -> "READ COMMITTED"
192− ReadUncommitted -> "READ UNCOMMITTED"
212+ ReadUncommitted -> "READ UNCOMMITTED"
193− RepeatableRead -> "REPEATABLE READ"
213+ RepeatableRead -> "REPEATABLE READ"
194
214
195-- | 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`.
196-- `ReadWrite` is the default. When a transaction is `ReadOnly`,
216-- `ReadWrite` is the default. When a transaction is `ReadOnly`,
@@ -207,10 +227,10 @@ data AccessMode
207 deriving (Show, Eq)
227 deriving (Show, Eq)
208
228
209-- | Render an `AccessMode`.
229-- | Render an `AccessMode`.
210−renderAccessMode :: AccessMode -> ByteString
230+instance RenderSQL AccessMode where
211−renderAccessMode = \case
231+ renderSQL = \case
212− ReadWrite -> "READ WRITE"
232+ ReadWrite -> "READ WRITE"
213− ReadOnly -> "READ ONLY"
233+ ReadOnly -> "READ ONLY"
214
234
215-- | The `Deferrable` transaction property has no effect
235-- | The `Deferrable` transaction property has no effect
216-- unless the transaction is also `Serializable` and `ReadOnly`.
236-- unless the transaction is also `Serializable` and `ReadOnly`.
@@ -226,7 +246,7 @@ data DeferrableMode
226 deriving (Show, Eq)
246 deriving (Show, Eq)
227
247
228-- | Render a `DeferrableMode`.
248-- | Render a `DeferrableMode`.
229−renderDeferrableMode :: DeferrableMode -> ByteString
249+instance RenderSQL DeferrableMode where
230−renderDeferrableMode = \case
250+ renderSQL = \case
231− Deferrable -> "DEFERRABLE"
251+ Deferrable -> "DEFERRABLE"
232− 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-11.1
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