064ddc0...dev · squeal

git.iko.soy/squeal

52 files changed+11427−4610

since splitsnapshots

unifiedsplit

.circleci/config.yml+3−2

@@ -2,9 +2,10 @@ version: 2

22jobs:

33 build:

44 docker:

5− - image: haskell:8.2.2

5+ - image: haskell:8.6.5

66 - image: circleci/postgres:latest

77 environment:

8+ POSTGRES_USER: root

89 POSTGRES_DB: exampledb

910 steps:

1011 - checkout

@@ -13,7 +14,7 @@ jobs:

1314 - dependency-cache

1415 - run: apt-get update && apt-get install -y libpq-dev xz-utils make

1516 - run: stack upgrade && stack update

16− - run: stack build

17+ - run: stack build --fast

1718 - run: stack test

1819 - run: stack haddock

1920 - save_cache:

README.md+83−87

@@ -45,7 +45,12 @@ composable and cover a large portion of SQL.

4545* connection pools

4646* transactions

4747* views

48−* composite and enumerated types

48+* array, composite and enumerated types

49+* json functions and operations

50+* multischema support

51+* correlated subqueries

52+* window functions

53+* text search

4954

5055## installation

5156

@@ -53,10 +58,16 @@ composable and cover a large portion of SQL.

5358

5459## testing

5560

56−start postgres on localhost port `5432` and create a database named `exampledb`.

61+Start postgres on localhost port `5432` and create a database named `exampledb`.

5762

5863`stack test`

5964

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+

6071## usage

6172

6273Let's see an example!

@@ -65,19 +76,17 @@ First, we need some language extensions because Squeal uses modern GHC

6576features.

6677

6778```Haskell

68−>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels

69−>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators

79+>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels -XFlexibleContexts

80+>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators -XGADTs

7081```

7182

7283We'll need some imports.

7384

7485```Haskell

75−>>> import Control.Monad (void)

76−>>> import Control.Monad.Base (liftBase)

86+>>> import Control.Monad.IO.Class (liftIO)

7787>>> import Data.Int (Int32)

7888>>> import Data.Text (Text)

7989>>> import Squeal.PostgreSQL

80−>>> import Squeal.PostgreSQL.Render

8190```

8291

8392We'll use generics to easily convert between Haskell and PostgreSQL values.

@@ -92,27 +101,27 @@ we use `DataKinds` and `TypeOperators`.

92101

93102```Haskell

94103>>> :{

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"] ]

95115type Schema =

96− '[ "users" ::: 'Table (

97− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

98− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

99− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

100− ])

101− , "emails" ::: 'Table (

102− '[ "pk_emails" ::: 'PrimaryKey '["id"]

103− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

104− ] :=>

105− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

106− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

107− , "email" ::: 'NoDef :=> 'Null 'PGtext

108− ])

109− ]

116+ '[ "users" ::: 'Table (UsersConstraints :=> UsersColumns)

117+ , "emails" ::: 'Table (EmailsConstraints :=> EmailsColumns) ]

118+type Schemas = Public Schema

110119:}

111120```

112121

113122Notice the use of type operators.

114123

115−`:::` is used to pair an alias `GHC.TypeLits.Symbol` with a `SchemumType`,

124+`:::` is used to pair an alias `Symbol` with a `SchemumType`,

116125a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's `::`

117126operator.

118127

@@ -121,7 +130,7 @@ yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,

121130yielding a `ColumnType`. It is intended to connote Haskell's `=>` operator

122131

123132Next, we'll write `Definition`s to set up and tear down the schema. In

124−Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`

133+Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`

125134has two type parameters, corresponding to the schema

126135before being run and the schema after. We can compose definitions using `>>>`.

127136Here and in the rest of our commands we make use of overloaded

@@ -130,19 +139,19 @@ labels to refer to named tables and columns in our schema.

130139```Haskell

131140>>> :{

132141let

133− setup :: Definition '[] Schema

134− setup =

142+ setup :: Definition (Public '[]) Schemas

143+ setup =

135144 createTable #users

136− ( serial `As` #id :*

137− (text & notNullable) `As` #name :* Nil )

138− ( primaryKey #id `As` #pk_users :* Nil ) >>>

145+ ( serial `as` #id :*

146+ (text & notNullable) `as` #name )

147+ ( primaryKey #id `as` #pk_users ) >>>

139148 createTable #emails

140− ( serial `As` #id :*

141− (int & notNullable) `As` #user_id :*

142− (text & nullable) `As` #email :* Nil )

143− ( primaryKey #id `As` #pk_emails :*

149+ ( serial `as` #id :*

150+ (int & notNullable) `as` #user_id :*

151+ (text & nullable) `as` #email )

152+ ( primaryKey #id `as` #pk_emails :*

144153 foreignKey #user_id #users #id

145− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

154+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

146155:}

147156```

148157

@@ -162,7 +171,7 @@ primary and foreign keys, making them somewhat complex. Our `teardown`

162171```Haskell

163172>>> :{

164173let

165− teardown :: Definition Schema '[]

174+ teardown :: Definition Schemas (Public '[])

166175 teardown = dropTable #emails >>> dropTable #users

167176:}

168177

@@ -171,57 +180,57 @@ DROP TABLE "emails";

171180DROP TABLE "users";

172181```

173182

174−Next, we'll write `Manipulation`s to insert data into our two tables.

175−A `Manipulation` like `insertRow`, `update` or `deleteFrom`

176−has three type parameters, the schema it refers to, a list of parameters

177−it can take as input, and a list of columns it produces as output. When

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+

192+Next, we'll write `Manipulation_`s to insert `User`s into our two tables.

193+A `Manipulation_` like `insertInto`, `update` or `deleteFrom`

194+has three type parameters, the schemas it refers to, input parameters

195+and an output row. When

178196we insert into the users table, we will need a parameter for the `name`

179197field but not for the `id` field. Since it's serial, we can use a default

180198value. However, since the emails table refers to the users table, we will

181199need to retrieve the user id that the insert generates and insert it into

182−the emails table. Take a careful look at the type and definition of both

183−of our inserts.

200+the emails table. We can do this in a single `Manipulation_` by using a

201+`with` statement.

184202

185203```Haskell

186204>>> :{

187205let

188− insertUser :: Manipulation Schema '[ 'NotNull 'PGtext ] '[ "fromOnly" ::: 'NotNull 'PGint4 ]

189− insertUser = insertRow #users

190− (Default `As` #id :* Set (param @1) `As` #name :* Nil)

191− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))

192−:}

193−

194−>>> :{

195−let

196− insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]

197− insertEmail = insertRow #emails

198− ( Default `As` #id :*

199− Set (param @1) `As` #user_id :*

200− Set (param @2) `As` #email :* Nil )

201− OnConflictDoNothing (Returning Nil)

206+ insertUser :: Manipulation_ Schemas User ()

207+ insertUser = with (u `as` #u) e

208+ where

209+ u = insertInto #users

210+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))

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))

202215:}

203216

204217>>> printSQL insertUser

205−INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING RETURNING "id" AS "fromOnly"

206−>>> printSQL insertEmail

207−INSERT INTO "emails" ("id", "user_id", "email") VALUES (DEFAULT, ($1 :: int4), ($2 :: text)) ON CONFLICT DO NOTHING

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"

208219```

209220

210−Next we write a `Query` to retrieve users from the database. We're not

221+Next we write a `Query_` to retrieve users from the database. We're not

211222interested in the ids here, just the usernames and email addresses. We

212−need to use an inner join to get the right result. A `Query` is like a

213−`Manipulation` with the same kind of type parameters.

223+need to use an `innerJoin` to get the right result. A `Query_` is like a

224+`Manipulation_` with the same kind of type parameters.

214225

215226```Haskell

216227>>> :{

217228let

218− getUsers :: Query Schema '[]

219− '[ "userName" ::: 'NotNull 'PGtext

220− , "userEmail" ::: 'Null 'PGtext ]

221− getUsers = select

222− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* Nil)

223− ( from (table (#users `As` #u)

224− & innerJoin (table (#emails `As` #e))

229+ getUsers :: Query_ Schemas () User

230+ getUsers = select_

231+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail)

232+ ( from (table (#users `as` #u)

233+ & innerJoin (table (#emails `as` #e))

225234 (#u ! #id .== #e ! #user_id)) )

226235:}

227236

@@ -229,25 +238,13 @@ let

229238SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

230239```

231240

232−Now that we've defined the SQL side of things, we'll need a Haskell type

233−for users. We give the type `Generics.SOP.Generic` and

234−`Generics.SOP.HasDatatypeInfo` instances so that we can decode the rows

235−we receive when we run `getUsers`. Notice that the record fields of the

236−`User` type match the column names of `getUsers`.

237−

238−```Haskell

239−>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, GHC.Generic)

240−>>> instance SOP.Generic User

241−>>> instance SOP.HasDatatypeInfo User

242−```

243−

244−Let's also create some users to add to the database.

241+Let's create some users to add to the database.

245242

246243```Haskell

247244>>> :{

248245let

249246 users :: [User]

250− users =

247+ users =

251248 [ User "Alice" (Just "alice@gmail.com")

252249 , User "Bob" Nothing

253250 , User "Carole" (Just "carole@hotmail.com")

@@ -266,19 +263,18 @@ transformer and when the schema doesn't change we can use `Monad` and

266263```Haskell

267264>>> :{

268265let

269− session :: PQ Schema Schema IO ()

266+ session :: PQ Schemas Schemas IO ()

270267 session = do

271− idResults <- traversePrepared insertUser (Only . userName <$> users)

272− ids <- traverse (fmap fromOnly . getRow 0) idResults

273− traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))

268+ _ <- traversePrepared_ insertUser users

274269 usersResult <- runQuery getUsers

275270 usersRows <- getRows usersResult

276− liftBase $ print (usersRows :: [User])

271+ liftIO $ print (usersRows :: [User])

277272in

278− void . withConnection "host=localhost port=5432 dbname=exampledb" $

273+ withConnection "host=localhost port=5432 dbname=exampledb" $

279274 define setup

280275 & pqThen session

281276 & pqThen (define teardown)

282277:}

283278[User {userName = "Alice", userEmail = Just "alice@gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just "carole@hotmail.com"}]

279+-}

284280```

RELEASE NOTES.md+837

@@ -1,5 +1,842 @@

11## RELEASE NOTES

3+### Version 0.5

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.

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+

3840### Version 0.3 - June 26, 2018

4841

5842Version 0.3 of Squeal adds views as well as composite and enumerated types to Squeal.

scrap-your-nils.mdnew file+60

@@ -0,0 +1,60 @@

1+## Scrap your Nils

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.

10+```Haskell

11+>>> import Generics.SOP (NP(..))

12+>>> :i NP

13+type role NP representational nominal

14+data NP (a :: k -> *) (b :: [k]) where

15+ Nil :: forall k (a :: k -> *). NP a '[]

16+ (:*) :: forall k (a :: k -> *) (x :: k) (xs :: [k]).

17+ (a x) -> (NP a xs) -> NP a (x : xs)

18+ -- Defined in ‘Generics.SOP.NP’

19+```

20+

21+This type allows us to construct "product" types, where the types of the individual

22+"terms" are hosted at the type level.

23+

24+```Haskell

25+>>> :set -XDataKinds

26+>>> import Generics.SOP (I(..))

27+>>> let example = I "foo" :* I pi :* Nil :: NP I '[String, Double]

28+>>> example

29+I "foo" :* I 3.141592653589793 :* Nil

30+```

31+

32+One thing Squeal uses `NP` for is to form lists of aliases,

33+using GHC's `OverloadedLabels` extension, hosting the names

34+of the aliases themselves at the type level.

35+

36+```Haskell

37+>>> :set -XKindSignatures -XOverloadedLabels -XFlexibleInstances -XMultiParamTypeClasses

38+>>> import GHC.TypeLits

39+>>> import GHC.OverloadedLabels

40+>>> data Alias (alias :: Symbol) = Alias deriving (Eq,Ord,Show)

41+>>> instance IsLabel label (Alias label) where fromLabel = Alias

42+>>> let aliases = #foo :* #bar :* Nil :: NP Alias '["foo", "bar"]

43+```

44+

45+However, it's very ugly to have to end every list with `:* Nil`.

46+When I announced the release of Squeal, people rightly [complained](https://www.reddit.com/r/haskell/comments/6yr5v6/announcing_squeal_a_deep_embedding_of_sql_in/dmq8vvn)

47+about the syntactic noise. Luckily, there's a neat trick we can use to get rid of it.

48+Making an `IsLabel` instance not only for elements of our list

49+but also for lists of length 1, we can ask GHC to interpret

50+the last label as a list.

51+

52+```Haskell

53+>>> instance IsLabel label (NP Alias '[label]) where fromLabel = Alias :* Nil

54+>>> let aliases' = #foo :* #bar :: NP Alias '["foo", "bar"]

55+```

56+

57+Version 0.3.1 of Squeal enables the "Scrap your Nils" trick for

58+heterogeneous lists of `Alias`es, `Aliased` expressions, `PGlabel`s and `By`s

59+with the typeclasses `IsLabel`, `IsQualified`, `IsPGlabel`,

60+and the new `Aliasable` typeclass, to eliminate all need of using `Nil` in a list.

squeal-postgresql/exe/Example.hs+46−49

@@ -11,8 +11,7 @@

1111

1212module Main (main, main2) where

1313

14−import Control.Monad (void)

15−import Control.Monad.Base (liftBase, MonadBase)

14+import Control.Monad.IO.Class (MonadIO (..))

1615import Data.Int (Int16, Int32)

1716import Data.Monoid ((<>))

1817import Data.Text (Text)

@@ -29,7 +28,7 @@ type Schema =

2928 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

3029 '[ "id" ::: 'Def :=> 'NotNull 'PGint4

3130 , "name" ::: 'NoDef :=> 'NotNull 'PGtext

32− , "vec" ::: 'NoDef :=> 'NotNull ('PGvararray 'PGint2)

31+ , "vec" ::: 'NoDef :=> 'NotNull ('PGvararray ('Null 'PGint2))

3332 ])

3433 , "emails" ::: 'Table (

3534 '[ "pk_emails" ::: 'PrimaryKey '["id"]

@@ -39,72 +38,70 @@ type Schema =

3938 , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

4039 , "email" ::: 'NoDef :=> 'Null 'PGtext

4140 ])

41+ , "positive" ::: 'Typedef 'PGfloat4

4242 ]

4343

44−setup :: Definition '[] Schema

45−setup =

44+type Schemas = Public Schema

45+

46+setup :: Definition (Public '[]) Schemas

47+setup =

4648 createTable #users

47− ( serial `As` #id :*

48− (text & notNullable) `As` #name :*

49− (vararray int2 & notNullable) `As` #vec :* Nil )

50− ( primaryKey #id `As` #pk_users :* Nil )

49+ ( serial `as` #id :*

50+ (text & notNullable) `as` #name :*

51+ (vararray int2 & notNullable) `as` #vec )

52+ ( primaryKey #id `as` #pk_users )

5153 >>>

5254 createTable #emails

53− ( serial `As` #id :*

54− (int & notNullable) `As` #user_id :*

55− (text & nullable) `As` #email :* Nil )

56− ( primaryKey #id `As` #pk_emails :*

55+ ( serial `as` #id :*

56+ hask @Int32 `as` #user_id :*

57+ hask @(Maybe Text) `as` #email )

58+ ( primaryKey #id `as` #pk_emails :*

5759 foreignKey #user_id #users #id

58− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

59−

60−teardown :: Definition Schema '[]

61−teardown = dropTable #emails >>> dropTable #users

62−

63−insertUser :: Manipulation Schema '[ 'NotNull 'PGtext, 'NotNull ('PGvararray 'PGint2)]

64− '[ "fromOnly" ::: 'NotNull 'PGint4 ]

65−insertUser = insertRows #users

66− (Default `As` #id :* Set (param @1) `As` #name :* Set (param @2) `As` #vec :* Nil) []

67− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))

68−

69−insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]

70−insertEmail = insertRows #emails

71− ( Default `As` #id :*

72− Set (param @1) `As` #user_id :*

73− Set (param @2) `As` #email :* Nil ) []

74− OnConflictDoNothing (Returning Nil)

75−

76−getUsers :: Query Schema '[]

77− '[ "userName" ::: 'NotNull 'PGtext

78− , "userEmail" ::: 'Null 'PGtext

79− , "userVec" ::: 'NotNull ('PGvararray 'PGint2)]

80−getUsers = select

81− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* #u ! #vec `As` #userVec :* Nil)

82− ( from (table (#users `As` #u)

83− & innerJoin (table (#emails `As` #e))

60+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

61+ >>>

62+ createDomain #positive real (#value .> 0 .&& (#value & isNotNull))

63+

64+teardown :: Definition Schemas (Public '[])

65+teardown = dropType #positive >>> dropTable #emails >>> dropTable #users

66+

67+insertUser :: Manipulation_ Schemas (Text, VarArray (Vector (Maybe Int16))) (Only Int32)

68+insertUser = insertInto #users

69+ (Values_ (Default `as` #id :* Set (param @1) `as` #name :* Set (param @2) `as` #vec))

70+ (OnConflict (OnConstraint #pk_users) DoNothing) (Returning_ (#id `as` #fromOnly))

71+

72+insertEmail :: Manipulation_ Schemas (Int32, Maybe Text) ()

73+insertEmail = insertInto_ #emails

74+ (Values_ (Default `as` #id :* Set (param @1) `as` #user_id :* Set (param @2) `as` #email))

75+

76+getUsers :: Query_ Schemas () User

77+getUsers = select_

78+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail :* #u ! #vec `as` #userVec)

79+ ( from (table (#users `as` #u)

80+ & innerJoin (table (#emails `as` #e))

8481 (#u ! #id .== #e ! #user_id)) )

8582

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)) }

8784 deriving (Show, GHC.Generic)

8885instance SOP.Generic User

8986instance SOP.HasDatatypeInfo User

9087

9188users :: [User]

92−users =

93− [ User "Alice" (Just "alice@gmail.com") [Nothing, Just 1]

94− , User "Bob" Nothing [Just 2, Nothing]

95− , User "Carole" (Just "carole@hotmail.com") [Just 3]

89+users =

90+ [ User "Alice" (Just "alice@gmail.com") (VarArray [Nothing, Just 1])

91+ , User "Bob" Nothing (VarArray [Just 2, Nothing])

92+ , User "Carole" (Just "carole@hotmail.com") (VarArray [Just 3])

9693 ]

9794

98−session :: (MonadBase IO pq, MonadPQ Schema pq) => pq ()

95+session :: (MonadIO pq, MonadPQ Schemas pq) => pq ()

9996session = do

100− liftBase $ Char8.putStrLn "manipulating"

97+ liftIO $ Char8.putStrLn "manipulating"

10198 idResults <- traversePrepared insertUser ([(userName user, userVec user) | user <- users])

10299 ids <- traverse (fmap fromOnly . getRow 0) idResults

103100 traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))

104− liftBase $ Char8.putStrLn "querying"

101+ liftIO $ Char8.putStrLn "querying"

105102 usersResult <- runQuery getUsers

106103 usersRows <- getRows usersResult

107− liftBase $ print (usersRows :: [User])

104+ liftIO $ print (usersRows :: [User])

108105

109106main :: IO ()

110107main = do

@@ -122,7 +119,7 @@ main = do

122119

123120main2 :: IO ()

124121main2 =

125− void . withConnection "host=localhost port=5432 dbname=exampledb" $

122+ withConnection "host=localhost port=5432 dbname=exampledb" $

126123 define setup

127124 & pqThen session

128125 & pqThen (define teardown)

squeal-postgresql/squeal-postgresql.cabal+71−10

@@ -1,5 +1,5 @@

11name: squeal-postgresql

2−version: 0.3.0.0

2+version: 0.5.1.0

33synopsis: Squeal PostgreSQL Library

44description: Squeal is a type-safe embedding of PostgreSQL in Haskell

55homepage: https://github.com/morphismtech/squeal

@@ -22,12 +22,40 @@ library

2222 hs-source-dirs: src

2323 exposed-modules:

2424 Squeal.PostgreSQL

25+ Squeal.PostgreSQL.Alias

2526 Squeal.PostgreSQL.Binary

2627 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

2735 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

2855 Squeal.PostgreSQL.Manipulation

2956 Squeal.PostgreSQL.Migration

3057 Squeal.PostgreSQL.Pool

58+ Squeal.PostgreSQL.PG

3159 Squeal.PostgreSQL.PQ

3260 Squeal.PostgreSQL.Render

3361 Squeal.PostgreSQL.Query

@@ -37,39 +65,73 @@ library

3765 ghc-options: -Wall

3866 build-depends:

3967 aeson >= 1.2.4.0

40− , base >= 4.10.1.0 && < 5.0

68+ , base >= 4.11.1.0 && < 5.0

4169 , binary-parser >= 0.5.5

4270 , bytestring >= 0.10.8.2

4371 , bytestring-strict-builder >= 0.4.5

4472 , deepseq >= 1.4.3.0

45− , generics-sop >= 0.3.2.0

46− , lifted-base >= 0.2.3.12

73+ , free-categories >= 0.1.0.0

74+ , generics-sop >= 0.3.2.0 && < 0.5.0.0

4775 , mmorph >= 1.1.1

48− , monad-control >= 1.0.2.3

4976 , mtl >= 2.2.2

5077 , network-ip >= 0.3.0.2

5178 , postgresql-binary >= 0.12.1

5279 , postgresql-libpq >= 0.9.4.1

80+ , records-sop >= 0.1.0.0

5381 , resource-pool >= 0.2.3.2

5482 , scientific >= 0.3.5.3

5583 , text >= 1.2.3.0

5684 , time >= 1.8.0.2

5785 , transformers >= 0.5.2.0

58− , transformers-base >= 0.4.4

86+ , unliftio >= 0.2.10

87+ , unliftio-pool >= 0.2.1.0

5988 , uuid-types >= 1.0.3

6089 , vector >= 0.12.0.1

6190

62−test-suite squeal-postgresql-doctest

91+test-suite doctest

6392 default-language: Haskell2010

6493 type: exitcode-stdio-1.0

6594 hs-source-dirs: test

6695 ghc-options: -Wall

67− main-is: DocTest.hs

96+ main-is: Doc.hs

6897 build-depends:

6998 base >= 4.10.0.0

7099 , doctest >= 0.11.4

100+ , squeal-postgresql

101+

102+test-suite properties

103+ default-language: Haskell2010

104+ type: exitcode-stdio-1.0

105+ hs-source-dirs: test

106+ ghc-options: -Wall

107+ main-is: Property.hs

108+ build-depends:

109+ base >= 4.10.0.0

110+ , bytestring >= 0.10.8.2

111+ , hedgehog >= 1.0

112+ , mtl >= 2.2.2

113+ , scientific >= 0.3.5.3

114+ , squeal-postgresql

115+ , time >= 1.8.0.2

116+

117+test-suite spec

118+ default-language: Haskell2010

119+ type: exitcode-stdio-1.0

120+ hs-source-dirs: test

121+ ghc-options: -Wall

122+ main-is: Spec.hs

123+ build-depends:

124+ base >= 4.10.0.0

125+ , async >= 2.2.2

126+ , bytestring >= 0.10.8.2

127+ , generics-sop >= 0.3.1.0

128+ , hspec >= 2.4.8

129+ , mtl >= 2.2.2

130+ , squeal-postgresql

131+ , text >= 1.2.2.2

132+ , vector >= 0.12.0.1

71133

72−executable squeal-postgresql-example

134+executable example

73135 default-language: Haskell2010

74136 hs-source-dirs: exe

75137 ghc-options: -Wall

@@ -82,5 +144,4 @@ executable squeal-postgresql-example

82144 , squeal-postgresql

83145 , text >= 1.2.2.2

84146 , transformers >= 0.5.2.0

85− , transformers-base >= 0.4.4

86147 , vector >= 0.12.0.1

squeal-postgresql/src/Squeal/PostgreSQL.hs+112−106

@@ -1,7 +1,7 @@

11{-|

22Module: Squeal.PostgreSQL

3−Description: Squeel export module

4−Copyright: (c) Eitan Chatav, 2017

3+Description: Squeal export module

4+Copyright: (c) Eitan Chatav, 2019

55Maintainer: eitan@morphism.tech

66Stability: experimental

@@ -11,17 +11,15 @@ Let's see an example!

1111First, we need some language extensions because Squeal uses modern GHC

1212features.

1313

14−>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels

15−>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators

16−

14+>>> :set -XDataKinds -XDeriveGeneric -XOverloadedLabels -XFlexibleContexts

15+>>> :set -XOverloadedStrings -XTypeApplications -XTypeOperators -XGADTs

16+

1717We'll need some imports.

1818

19−>>> import Control.Monad (void)

20−>>> import Control.Monad.Base (liftBase)

19+>>> import Control.Monad.IO.Class (liftIO)

2120>>> import Data.Int (Int32)

2221>>> import Data.Text (Text)

2322>>> import Squeal.PostgreSQL

24−>>> import Squeal.PostgreSQL.Render

2523

2624We'll use generics to easily convert between Haskell and PostgreSQL values.

2725

@@ -32,26 +30,26 @@ The first step is to define the schema of our database. This is where

3230we use @DataKinds@ and @TypeOperators@.

3331

3432>>> :{

33+type UsersColumns =

34+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

35+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext ]

36+type UsersConstraints = '[ "pk_users" ::: 'PrimaryKey '["id"] ]

37+type EmailsColumns =

38+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

39+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

40+ , "email" ::: 'NoDef :=> 'Null 'PGtext ]

41+type EmailsConstraints =

42+ '[ "pk_emails" ::: 'PrimaryKey '["id"]

43+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"] ]

3544type Schema =

36− '[ "users" ::: 'Table (

37− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

38− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

39− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

40− ])

41− , "emails" ::: 'Table (

42− '[ "pk_emails" ::: 'PrimaryKey '["id"]

43− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

44− ] :=>

45− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

46− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

47− , "email" ::: 'NoDef :=> 'Null 'PGtext

48− ])

49− ]

45+ '[ "users" ::: 'Table (UsersConstraints :=> UsersColumns)

46+ , "emails" ::: 'Table (EmailsConstraints :=> EmailsColumns) ]

47+type Schemas = Public Schema

5048:}

5149

5250Notice the use of type operators.

5351

54−`:::` is used to pair an alias `GHC.TypeLits.Symbol` with a `SchemumType`,

52+`:::` is used to pair an alias `GHC.TypeLits.Symbol` with a `SchemasType`, a `SchemumType`,

5553a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's @::@

5654operator.

5755

@@ -60,7 +58,7 @@ yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,

6058yielding a `ColumnType`. It is intended to connote Haskell's @=>@ operator

6159

6260Next, we'll write `Definition`s to set up and tear down the schema. In

63−Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`

61+Squeal, a `Definition` like `createTable`, `alterTable` or `dropTable`

6462has two type parameters, corresponding to the schema

6563before being run and the schema after. We can compose definitions using `>>>`.

6664Here and in the rest of our commands we make use of overloaded

@@ -68,19 +66,19 @@ labels to refer to named tables and columns in our schema.

6866

6967>>> :{

7068let

71− setup :: Definition '[] Schema

72− setup =

69+ setup :: Definition (Public '[]) Schemas

70+ setup =

7371 createTable #users

74− ( serial `As` #id :*

75− (text & notNullable) `As` #name :* Nil )

76− ( primaryKey #id `As` #pk_users :* Nil ) >>>

72+ ( serial `as` #id :*

73+ (text & notNullable) `as` #name )

74+ ( primaryKey #id `as` #pk_users ) >>>

7775 createTable #emails

78− ( serial `As` #id :*

79− (int & notNullable) `As` #user_id :*

80− (text & nullable) `As` #email :* Nil )

81− ( primaryKey #id `As` #pk_emails :*

76+ ( serial `as` #id :*

77+ (int & notNullable) `as` #user_id :*

78+ (text & nullable) `as` #email )

79+ ( primaryKey #id `as` #pk_emails :*

8280 foreignKey #user_id #users #id

83− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

81+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

8482:}

8583

8684We can easily see the generated SQL is unsurprising looking.

@@ -89,14 +87,14 @@ We can easily see the generated SQL is unsurprising looking.

8987CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));

9088CREATE 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);

9189

92−Notice that @setup@ starts with an empty schema @'[]@ and produces @Schema@.

90+Notice that @setup@ starts with an empty public schema @(Public '[])@ and produces @Schemas@.

9391In our `createTable` commands we included `TableConstraint`s to define

9492primary and foreign keys, making them somewhat complex. Our @teardown@

9593`Definition` is simpler.

9694

9795>>> :{

9896let

99− teardown :: Definition Schema '[]

97+ teardown :: Definition Schemas (Public '[])

10098 teardown = dropTable #emails >>> dropTable #users

10199:}

102100

@@ -104,76 +102,64 @@ let

104102DROP TABLE "emails";

105103DROP TABLE "users";

106104

107−Next, we'll write `Manipulation`s to insert data into our two tables.

108−A `Manipulation` like `insertRow`, `update` or `deleteFrom`

109−has three type parameters, the schema it refers to, a list of parameters

110−it can take as input, and a list of columns it produces as output. When

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+

112+Next, we'll write `Manipulation_`s to insert @User@s into our two tables.

113+A `Manipulation_` like `insertInto`, `update` or `deleteFrom`

114+has three type parameters, the schemas it refers to, input parameters

115+and an output row. When

111116we insert into the users table, we will need a parameter for the @name@

112117field but not for the @id@ field. Since it's serial, we can use a default

113118value. However, since the emails table refers to the users table, we will

114119need to retrieve the user id that the insert generates and insert it into

115−the emails table. Take a careful look at the type and definition of both

116−of our inserts.

117−

118−>>> :{

119−let

120− insertUser :: Manipulation Schema '[ 'NotNull 'PGtext ] '[ "fromOnly" ::: 'NotNull 'PGint4 ]

121− insertUser = insertRow #users

122− (Default `As` #id :* Set (param @1) `As` #name :* Nil)

123− OnConflictDoNothing (Returning (#id `As` #fromOnly :* Nil))

124−:}

120+the emails table. We can do this in a single `Manipulation_` by using a

121+`with` statement.

125122

126123>>> :{

127124let

128− insertEmail :: Manipulation Schema '[ 'NotNull 'PGint4, 'Null 'PGtext] '[]

129− insertEmail = insertRow #emails

130− ( Default `As` #id :*

131− Set (param @1) `As` #user_id :*

132− Set (param @2) `As` #email :* Nil )

133− OnConflictDoNothing (Returning Nil)

125+ insertUser :: Manipulation_ Schemas User ()

126+ insertUser = with (u `as` #u) e

127+ where

128+ u = insertInto #users

129+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))

130+ OnConflictDoRaise (Returning_ (#id :* param @2 `as` #email))

131+ e = insertInto_ #emails $ Select

132+ (Default `as` #id :* Set (#u ! #id) `as` #user_id :* Set (#u ! #email) `as` #email)

133+ (from (common #u))

134134:}

135135

136136>>> printSQL insertUser

137−INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING RETURNING "id" AS "fromOnly"

138−>>> printSQL insertEmail

139−INSERT INTO "emails" ("id", "user_id", "email") VALUES (DEFAULT, ($1 :: int4), ($2 :: text)) ON CONFLICT DO NOTHING

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"

140138

141−Next we write a `Query` to retrieve users from the database. We're not

139+Next we write a `Query_` to retrieve users from the database. We're not

142140interested in the ids here, just the usernames and email addresses. We

143−need to use an inner join to get the right result. A `Query` is like a

144−`Manipulation` with the same kind of type parameters.

141+need to use an `innerJoin` to get the right result. A `Query_` is like a

142+`Manipulation_` with the same kind of type parameters.

145143

146144>>> :{

147145let

148− getUsers :: Query Schema '[]

149− '[ "userName" ::: 'NotNull 'PGtext

150− , "userEmail" ::: 'Null 'PGtext ]

151− getUsers = select

152− (#u ! #name `As` #userName :* #e ! #email `As` #userEmail :* Nil)

153− ( from (table (#users `As` #u)

154− & innerJoin (table (#emails `As` #e))

146+ getUsers :: Query_ Schemas () User

147+ getUsers = select_

148+ (#u ! #name `as` #userName :* #e ! #email `as` #userEmail)

149+ ( from (table (#users `as` #u)

150+ & innerJoin (table (#emails `as` #e))

155151 (#u ! #id .== #e ! #user_id)) )

156152:}

157153

158154>>> printSQL getUsers

159155SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

160156

161−Now that we've defined the SQL side of things, we'll need a Haskell type

162−for users. We give the type `Generics.SOP.Generic` and

163−`Generics.SOP.HasDatatypeInfo` instances so that we can decode the rows

164−we receive when we run @getUsers@. Notice that the record fields of the

165−@User@ type match the column names of @getUsers@.

166−

167−>>> data User = User { userName :: Text, userEmail :: Maybe Text } deriving (Show, GHC.Generic)

168−>>> instance SOP.Generic User

169−>>> instance SOP.HasDatatypeInfo User

170−

171−Let's also create some users to add to the database.

157+Let's create some users to add to the database.

172158

173159>>> :{

174160let

175161 users :: [User]

176− users =

162+ users =

177163 [ User "Alice" (Just "alice@gmail.com")

178164 , User "Bob" Nothing

179165 , User "Carole" (Just "carole@hotmail.com")

@@ -190,38 +176,58 @@ transformer and when the schema doesn't change we can use `Monad` and

190176

191177>>> :{

192178let

193− session :: PQ Schema Schema IO ()

179+ session :: PQ Schemas Schemas IO ()

194180 session = do

195− idResults <- traversePrepared insertUser (Only . userName <$> users)

196− ids <- traverse (fmap fromOnly . getRow 0) idResults

197− traversePrepared_ insertEmail (zip (ids :: [Int32]) (userEmail <$> users))

181+ _ <- traversePrepared_ insertUser users

198182 usersResult <- runQuery getUsers

199183 usersRows <- getRows usersResult

200− liftBase $ print (usersRows :: [User])

184+ liftIO $ print (usersRows :: [User])

201185in

202− void . withConnection "host=localhost port=5432 dbname=exampledb" $

186+ withConnection "host=localhost port=5432 dbname=exampledb" $

203187 define setup

204188 & pqThen session

205189 & pqThen (define teardown)

206190:}

207191[User {userName = "Alice", userEmail = Just "alice@gmail.com"},User {userName = "Bob", userEmail = Nothing},User {userName = "Carole", userEmail = Just "carole@hotmail.com"}]

208192-}

209−module Squeal.PostgreSQL

210− ( module Squeal.PostgreSQL.Binary

211− , module Squeal.PostgreSQL.Definition

212− , module Squeal.PostgreSQL.Expression

213− , module Squeal.PostgreSQL.Manipulation

214− , module Squeal.PostgreSQL.PQ

215− , module Squeal.PostgreSQL.Query

216− , module Squeal.PostgreSQL.Schema

217− , module Squeal.PostgreSQL.Transaction

218− ) where

219−

220−import Squeal.PostgreSQL.Binary

221−import Squeal.PostgreSQL.Definition

222−import Squeal.PostgreSQL.Expression

223−import Squeal.PostgreSQL.Manipulation

224−import Squeal.PostgreSQL.PQ

225−import Squeal.PostgreSQL.Query

226−import Squeal.PostgreSQL.Schema

227−import Squeal.PostgreSQL.Transaction

193+module Squeal.PostgreSQL (module X, RenderSQL(..), printSQL) where

194+

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

203+import Squeal.PostgreSQL.Definition.Type as X

204+import Squeal.PostgreSQL.Definition.View as X

205+import Squeal.PostgreSQL.Expression as X

206+import Squeal.PostgreSQL.Expression.Aggregate as X

207+import Squeal.PostgreSQL.Expression.Collection as X

208+import Squeal.PostgreSQL.Expression.Comparison as X

209+import Squeal.PostgreSQL.Expression.Json as X

210+import Squeal.PostgreSQL.Expression.Literal as X

211+import Squeal.PostgreSQL.Expression.Logic as X

212+import Squeal.PostgreSQL.Expression.Math as X

213+import Squeal.PostgreSQL.Expression.Null as X

214+import Squeal.PostgreSQL.Expression.Parameter as X

215+import Squeal.PostgreSQL.Expression.Range as X

216+import Squeal.PostgreSQL.Expression.Set as X

217+import Squeal.PostgreSQL.Expression.Sort as X

218+import Squeal.PostgreSQL.Expression.Subquery as X

219+import Squeal.PostgreSQL.Expression.Text as X

220+import Squeal.PostgreSQL.Expression.TextSearch as X

221+import Squeal.PostgreSQL.Expression.Time as X

222+import Squeal.PostgreSQL.Expression.Type as X

223+import Squeal.PostgreSQL.Expression.Window as X

224+import Squeal.PostgreSQL.List as X

225+import Squeal.PostgreSQL.Manipulation as X

226+import Squeal.PostgreSQL.Migration as X

227+import Squeal.PostgreSQL.PG as X

228+import Squeal.PostgreSQL.Pool as X

229+import Squeal.PostgreSQL.PQ as X

230+import Squeal.PostgreSQL.Query as X

231+import Squeal.PostgreSQL.Render (RenderSQL(..), printSQL)

232+import Squeal.PostgreSQL.Schema as X

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

8+This module embeds Postgres's alias system in Haskell in

9+a typesafe fashion. Thanks to GHC's @OverloadedLabels@ extension,

10+Squeal can reference aliases by prepending with a @#@.

11+-}

12+

13+{-# LANGUAGE

14+ AllowAmbiguousTypes

15+ , ConstraintKinds

16+ , DeriveAnyClass

17+ , DeriveGeneric

18+ , FlexibleContexts

19+ , FlexibleInstances

20+ , FunctionalDependencies

21+ , GADTs

22+ , LambdaCase

23+ , OverloadedStrings

24+ , QuantifiedConstraints

25+ , RankNTypes

26+ , ScopedTypeVariables

27+ , StandaloneDeriving

28+ , TypeApplications

29+ , TypeFamilyDependencies

30+ , TypeInType

31+ , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

34+#-}

35+

36+module Squeal.PostgreSQL.Alias

37+ ( (:::)

38+ , Alias (..)

39+ , IsLabel (..)

40+ , Aliased (As)

41+ , Aliasable (as)

42+ , renderAliased

43+ , Has

44+ , HasUnique

45+ , HasAll

46+ , HasIn

47+ , QualifiedAlias (..)

48+ , IsQualified (..)

49+ -- * Grouping

50+ , Grouping (..)

51+ , GroupedBy

52+ ) where

53+

54+import Control.DeepSeq

55+import Data.ByteString (ByteString)

56+import Data.String (fromString)

57+import GHC.OverloadedLabels

58+import GHC.TypeLits

59+

60+import qualified Generics.SOP as SOP

61+import qualified GHC.Generics as GHC

62+

63+import Squeal.PostgreSQL.List

64+import Squeal.PostgreSQL.Render

65+

66+-- $setup

67+-- >>> import Squeal.PostgreSQL

68+

69+-- | The alias operator `:::` is like a promoted version of `As`,

70+-- a type level pair between an alias and some type.

71+type (:::) (alias :: Symbol) ty = '(alias,ty)

72+infixr 6 :::

73+

74+

75+-- | `Grouping` is an auxiliary namespace, created by

76+-- @GROUP BY@ clauses (`Squeal.PostgreSQL.Query.group`), and used

77+-- for typesafe aggregation

78+data Grouping

79+ = Ungrouped -- ^ no aggregation permitted

80+ | Grouped [(Symbol,Symbol)] -- ^ aggregation required for any column which is not grouped

81+

82+{- | A `GroupedBy` constraint indicates that a table qualified column is

83+a member of the auxiliary namespace created by @GROUP BY@ clauses and thus,

84+may be called in an output `Squeal.PostgreSQL.Expression.Expression` without aggregating.

85+-}

86+class (KnownSymbol table, KnownSymbol column)

87+ => GroupedBy table column bys where

88+instance {-# OVERLAPPING #-} (KnownSymbol table, KnownSymbol column)

89+ => GroupedBy table column ('(table,column) ': bys)

90+instance {-# OVERLAPPABLE #-}

91+ ( KnownSymbol table

92+ , KnownSymbol column

93+ , GroupedBy table column bys

94+ ) => GroupedBy table column (tabcol ': bys)

95+

96+-- | `Alias`es are proxies for a type level string or `Symbol`

97+-- and have an `IsLabel` instance so that with @-XOverloadedLabels@

98+--

99+-- >>> :set -XOverloadedLabels

100+-- >>> #foobar :: Alias "foobar"

101+-- Alias

102+data Alias (alias :: Symbol) = Alias

103+ deriving (Eq,GHC.Generic,Ord,Show,NFData)

104+instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where

105+ fromLabel = Alias

106+instance aliases ~ '[alias] => IsLabel alias (NP Alias aliases) where

107+ fromLabel = fromLabel SOP.:* Nil

108+-- | >>> printSQL (#jimbob :: Alias "jimbob")

109+-- "jimbob"

110+instance KnownSymbol alias => RenderSQL (Alias alias) where

111+ renderSQL = doubleQuoted . fromString . symbolVal

112+

113+-- >>> printSQL (#jimbob :* #kandi :: NP Alias '["jimbob", "kandi"])

114+-- "jimbob", "kandi"

115+instance SOP.All KnownSymbol aliases => RenderSQL (NP Alias aliases) where

116+ renderSQL

117+ = commaSeparated

118+ . SOP.hcollapse

119+ . SOP.hcmap (SOP.Proxy @KnownSymbol) (SOP.K . renderSQL)

120+

121+-- | The `As` operator is used to name an expression. `As` is like a demoted

122+-- version of `:::`.

123+--

124+-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)

125+-- As (Just "hello") Alias

126+data Aliased expression aliased where

127+ As

128+ :: KnownSymbol alias

129+ => expression ty

130+ -> Alias alias

131+ -> Aliased expression (alias ::: ty)

132+deriving instance Show (expression ty)

133+ => Show (Aliased expression (alias ::: ty))

134+deriving instance Eq (expression ty)

135+ => Eq (Aliased expression (alias ::: ty))

136+deriving instance Ord (expression ty)

137+ => Ord (Aliased expression (alias ::: ty))

138+instance (alias0 ~ alias1, alias0 ~ alias2, KnownSymbol alias2)

139+ => IsLabel alias0 (Aliased Alias (alias1 ::: alias2)) where

140+ fromLabel = fromLabel @alias2 `As` fromLabel @alias1

141+

142+-- | The `Aliasable` class provides a way to scrap your `Nil`s

143+-- in an `NP` list of `Aliased` expressions.

144+class KnownSymbol alias => Aliasable alias expression aliased

145+ | aliased -> expression

146+ , aliased -> alias

147+ where as :: expression -> Alias alias -> aliased

148+instance (KnownSymbol alias, aliased ~ (alias ::: ty)) => Aliasable alias

149+ (expression ty)

150+ (Aliased expression aliased)

151+ where

152+ as = As

153+instance (KnownSymbol alias, tys ~ '[alias ::: ty]) => Aliasable alias

154+ (expression ty)

155+ (NP (Aliased expression) tys)

156+ where

157+ expression `as` alias = expression `As` alias SOP.:* Nil

158+

159+-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")

160+-- >>> renderAliased renderMaybe (Just (3::Int) `As` #an_int)

161+-- "Just AS \"an_int\""

162+renderAliased

163+ :: (forall ty. expression ty -> ByteString)

164+ -> Aliased expression aliased

165+ -> ByteString

166+renderAliased render (expression `As` alias) =

167+ render expression <> " AS " <> renderSQL alias

168+

169+-- | @HasUnique alias fields field@ is a constraint that proves that

170+-- @fields@ is a singleton of @alias ::: field@.

171+type HasUnique alias fields field = fields ~ '[alias ::: field]

172+

173+-- | @Has alias fields field@ is a constraint that proves that

174+-- @fields@ has a field of @alias ::: field@, inferring @field@

175+-- from @alias@ and @fields@.

176+class KnownSymbol alias =>

177+ Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)

178+ | alias fields -> field where

179+instance {-# OVERLAPPING #-} KnownSymbol alias

180+ => Has alias (alias ::: field ': fields) field

181+instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)

182+ => Has alias (field' ': fields) field

183+

184+{-| @HasIn fields (alias ::: field)@ is a constraint that proves that

185+@fields@ has a field of @alias ::: field@. It is used in @UPDATE@s to

186+choose which subfields to update.

187+-}

188+class HasIn fields field where

189+instance (Has alias fields field) => HasIn fields (alias ::: field) where

190+

191+-- | `HasAll` extends `Has` to take lists of @aliases@ and @fields@ and infer

192+-- a list of @subfields@.

193+class

194+ ( SOP.All KnownSymbol aliases

195+ ) => HasAll

196+ (aliases :: [Symbol])

197+ (fields :: [(Symbol,kind)])

198+ (subfields :: [(Symbol,kind)])

199+ | aliases fields -> subfields where

200+instance {-# OVERLAPPING #-} HasAll '[] fields '[]

201+instance {-# OVERLAPPABLE #-}

202+ (Has alias fields field, HasAll aliases fields subfields)

203+ => HasAll (alias ': aliases) fields (alias ::: field ': subfields)

204+

205+-- | Analagous to `IsLabel`, the constraint

206+-- `IsQualified` defines `!` for a column alias qualified

207+-- by a table alias.

208+class IsQualified table column expression where

209+ (!) :: Alias table -> Alias column -> expression

210+ infixl 9 !

211+instance IsQualified table column (Alias table, Alias column) where (!) = (,)

212+

213+{-| `QualifiedAlias`es enables multi-schema support by allowing a reference

214+to a `Squeal.PostgreSQL.Schema.Table`, `Squeal.PostgreSQL.Schema.Typedef`

215+or `Squeal.PostgreSQL.Schema.View` to be qualified by their schemas. By default,

216+a qualifier of @public@ is provided.

217+

218+>>> :{

219+let

220+ alias1 :: QualifiedAlias "sch" "tab"

221+ alias1 = #sch ! #tab

222+ alias2 :: QualifiedAlias "public" "vw"

223+ alias2 = #vw

224+in printSQL alias1 >> printSQL alias2

225+:}

226+"sch"."tab"

227+"vw"

228+-}

229+data QualifiedAlias (qualifier :: Symbol) (alias :: Symbol) = QualifiedAlias

230+ deriving (Eq,GHC.Generic,Ord,Show,NFData)

231+instance (q ~ q', a ~ a') => IsQualified q a (QualifiedAlias q' a') where

232+ _!_ = QualifiedAlias

233+instance (q' ~ "public", a ~ a') => IsLabel a (QualifiedAlias q' a') where

234+ fromLabel = QualifiedAlias

235+instance (q0 ~ q1, a0 ~ a1, a1 ~ a2, KnownSymbol a2) =>

236+ IsQualified q0 a0 (Aliased (QualifiedAlias q1) (a1 ::: a2)) where

237+ _!_ = QualifiedAlias `As` Alias

238+instance (q ~ "public", a0 ~ a1, a1 ~ a2, KnownSymbol a2) =>

239+ IsLabel a0 (Aliased (QualifiedAlias q) (a1 ::: a2)) where

240+ fromLabel = QualifiedAlias `As` Alias

241+

242+instance (KnownSymbol q, KnownSymbol a)

243+ => RenderSQL (QualifiedAlias q a) where

244+ renderSQL _ =

245+ let

246+ qualifier = renderSQL (Alias @q)

247+ alias = renderSQL (Alias @a)

248+ in

249+ if qualifier == "\"public\"" then alias else qualifier <> "." <> alias

squeal-postgresql/src/Squeal/PostgreSQL/Binary.hs+534−221

@@ -7,103 +7,157 @@ Stability: experimental

88This module provides binary encoding and decoding between Haskell and PostgreSQL types.

10−Instances are governed by the `Generic` and `HasDatatypeInfo` typeclasses, so you absolutely

10+Instances are governed by the `SOP.Generic` and `SOP.HasDatatypeInfo` typeclasses, so you absolutely

1111do not need to define your own instances to decode retrieved rows into Haskell values or

1212to encode Haskell values into statement parameters.

1313

14+Let's see some examples. We'll need some imports

15+

1416>>> import Data.Int (Int16)

1517>>> 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.

1624

17−>>> data Row = Row { col1 :: Int16, col2 :: Text } deriving (Eq, GHC.Generic)

25+>>> data Row = Row { col1 :: Int16, col2 :: Text, col3 :: Maybe Bool } deriving (Eq, GHC.Generic)

1826>>> instance Generic Row

1927>>> 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+:}

2036

21−>>> import Control.Monad (void)

22−>>> import Control.Monad.Base (liftBase)

23−>>> import Squeal.PostgreSQL

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.

2439

40+>>> let input = Row 2 "hi" (Just True)

2541>>> :{

26−let

27− query :: Query '[]

28− '[ 'NotNull 'PGint2, 'NotNull 'PGtext]

29− '["col1" ::: 'NotNull 'PGint2, "col2" ::: 'NotNull 'PGtext]

30− query = values_ (param @1 `As` #col1 :* param @2 `As` #col2 :* Nil)

42+withConnection "host=localhost port=5432 dbname=exampledb" $ do

43+ result <- runQueryParams roundTrip input

44+ Just output <- firstRow result

45+ liftIO . print $ input == output

3146:}

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.

3268

3369>>> :{

3470let

35− roundtrip :: IO ()

36− roundtrip = void . withConnection "host=localhost port=5432 dbname=exampledb" $ do

37− result <- runQueryParams query (2 :: Int16, "hi" :: Text)

38− Just row <- firstRow result

39− liftBase . print $ row == Row 2 "hi"

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

4076:}

4177

42−>>> roundtrip

78+>>> :set -XOverloadedLists

79+>>> let input = Row (VarArray [1,2]) (FixArray (Just 1,Nothing)) (FixArray ((1,2),(3,4),(5,6)))

80+>>> :{

81+withConnection "host=localhost port=5432 dbname=exampledb" $ do

82+ result <- runQueryParams roundTrip input

83+ Just output <- firstRow result

84+ liftIO . print $ input == output

85+:}

4386True

4487

45−In addition to being able to encode and decode basic Haskell types like `Int16` and `Text`,

46−Squeal permits you to encode and decode Haskell types which are equivalent to

47−Postgres enumerated and composite types.

48−

4988Enumerated (enum) types are data types that comprise a static, ordered set of values.

5089They are equivalent to Haskell algebraic data types whose constructors are nullary.

5190An example of an enum type might be the days of the week,

5291or a set of status values for a piece of data.

5392

54−>>> data Schwarma = Beef | Lamb | Chicken deriving (Show, GHC.Generic)

93+>>> data Schwarma = Beef | Lamb | Chicken deriving (Eq, Show, GHC.Generic)

5594>>> instance Generic Schwarma

5695>>> instance HasDatatypeInfo Schwarma

5796

5897A composite type represents the structure of a row or record;

59−it is essentially just a list of field names and their data types. They are almost

60−equivalent to Haskell record types. However, because of the potential presence of @NULL@

61−all the record fields must be `Maybe`s of basic types.

98+it is essentially just a list of field names and their data types.

6299

63−>>> data Person = Person {name :: Maybe Text, age :: Maybe Int32} deriving (Show, GHC.Generic)

100+>>> data Person = Person {name :: Text, age :: Int32} deriving (Eq, Show, GHC.Generic)

64101>>> instance Generic Person

65102>>> instance HasDatatypeInfo Person

103+>>> instance Aeson.FromJSON Person

104+>>> instance Aeson.ToJSON Person

66105

67106We can create the equivalent Postgres types directly from their Haskell types.

68107

69108>>> :{

70109type Schema =

71− '[ "schwarma" ::: 'Typedef (EnumFrom Schwarma)

72− , "person" ::: 'Typedef (CompositeFrom Person)

110+ '[ "schwarma" ::: 'Typedef (PG (Enumerated Schwarma))

111+ , "person" ::: 'Typedef (PG (Composite Person))

73112 ]

74113:}

75114

76115>>> :{

77116let

78− setup :: Definition '[] Schema

117+ setup :: Definition (Public '[]) (Public Schema)

79118 setup =

80119 createTypeEnumFrom @Schwarma #schwarma >>>

81120 createTypeCompositeFrom @Person #person

82121:}

83122

84−Then we can perform roundtrip queries;

123+Let's demonstrate how to associate our Haskell types @Schwarma@ and @Person@

124+with enumerated, composite or json types in Postgres. First create a Haskell

125+@Row@ type using the `Enumerated`, `Composite` and `Json` newtypes as fields.

85126

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

86137>>> :{

87138let

88− querySchwarma :: Query Schema

89− '[ 'NotNull (EnumFrom Schwarma)]

90− '["fromOnly" ::: 'NotNull (EnumFrom Schwarma)]

91− querySchwarma = values_ (parameter @1 #schwarma `As` #fromOnly :* Nil)

139+ input = Row

140+ (Enumerated Chicken)

141+ (Composite (Person "Faisal" 24))

142+ (Json (Person "Ahmad" 48))

92143:}

93144

145+Once again, define a round trip query.

146+

94147>>> :{

95148let

96− queryPerson :: Query Schema

97− '[ 'NotNull (CompositeFrom Person)]

98− '["fromOnly" ::: 'NotNull (CompositeFrom Person)]

99− queryPerson = values_ (parameter @1 #person `As` #fromOnly :* Nil)

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

100154:}

101155

102−And finally drop the types.

156+Finally, we can drop our type definitions.

103157

104158>>> :{

105159let

106− teardown :: Definition Schema '[]

160+ teardown :: Definition (Public Schema) (Public '[])

107161 teardown = dropType #schwarma >>> dropType #person

108162:}

109163

@@ -112,20 +166,16 @@ Now let's run it.

112166>>> :{

113167let

114168 session = do

115− result1 <- runQueryParams querySchwarma (Only Chicken)

116− Just (Only schwarma) <- firstRow result1

117− liftBase $ print (schwarma :: Schwarma)

118− result2 <- runQueryParams queryPerson (Only (Person (Just "Faisal") (Just 24)))

119− Just (Only person) <- firstRow result2

120− liftBase $ print (person :: Person)

169+ result <- runQueryParams roundTrip input

170+ Just output <- firstRow result

171+ liftIO . print $ input == output

121172in

122− void . withConnection "host=localhost port=5432 dbname=exampledb" $

173+ withConnection "host=localhost port=5432 dbname=exampledb" $

123174 define setup

124175 & pqThen session

125176 & pqThen (define teardown)

126177:}

127−Chicken

128−Person {name = Just "Faisal", age = Just 24}

178+True

129179-}

130180

131181{-# LANGUAGE

@@ -134,55 +184,76 @@ Person {name = Just "Faisal", age = Just 24}

134184 , DeriveFunctor

135185 , DeriveGeneric

136186 , DeriveTraversable

187+ , DefaultSignatures

137188 , FlexibleContexts

138189 , FlexibleInstances

190+ , FunctionalDependencies

139191 , GADTs

140192 , LambdaCase

193+ , OverloadedStrings

141194 , MultiParamTypeClasses

142195 , ScopedTypeVariables

143196 , TypeApplications

197+ , TypeFamilies

144198 , TypeInType

145199 , TypeOperators

146200 , UndecidableInstances

201+ , UndecidableSuperClasses

147202#-}

148203

149204module Squeal.PostgreSQL.Binary

150205 ( -- * Encoding

151206 ToParam (..)

152− , ToColumnParam (..)

153207 , ToParams (..)

208+ , ToNullityParam (..)

209+ , ToField (..)

210+ , ToFixArray (..)

154211 -- * Decoding

155212 , FromValue (..)

156− , FromColumnValue (..)

157213 , FromRow (..)

214+ , FromField (..)

215+ , FromFixArray (..)

158216 -- * Only

159217 , Only (..)

218+ -- * Oid

219+ , OidOf (..)

220+ , OidOfParam (..)

221+ , OidOfField (..)

160222 ) where

161223

162224import BinaryParser

163−import ByteString.StrictBuilder

164−import Data.Aeson hiding (Null)

225+import ByteString.StrictBuilder (builderLength, int32BE, int64BE, word32BE)

226+import Control.Arrow (left)

227+import Control.Monad

165228import Data.Int

166229import Data.Kind

167−import Data.Monoid hiding (All)

168230import Data.Scientific

169231import Data.Time

170232import Data.UUID.Types

171233import Data.Vector (Vector)

172234import Data.Word

235+import Foreign.C.Types (CUInt(CUInt))

173236import Generics.SOP

237+import Generics.SOP.Record

174238import GHC.TypeLits

175239import Network.IP.Addr

176240

177−import qualified Data.ByteString.Lazy as Lazy

178−import qualified Data.ByteString as Strict hiding (pack, unpack)

179−import qualified Data.Text.Lazy as Lazy

180−import qualified Data.Text as Strict

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

244+import qualified Data.ByteString as Strict (ByteString)

245+import qualified Data.Text.Lazy as Lazy (Text)

246+import qualified Data.Text as Strict (Text)

247+import qualified Data.Text as Strict.Text

181248import qualified Data.Vector as Vector

249+import qualified Database.PostgreSQL.LibPQ as LibPQ

182250import qualified GHC.Generics as GHC

183251import qualified PostgreSQL.Binary.Decoding as Decoding

184252import qualified PostgreSQL.Binary.Encoding as Encoding

185253

254+import Squeal.PostgreSQL.Alias

255+import Squeal.PostgreSQL.List

256+import Squeal.PostgreSQL.PG

186257import Squeal.PostgreSQL.Schema

187258

188259-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into

@@ -206,19 +277,20 @@ class ToParam (x :: Type) (pg :: PGType) where

206277 toParam :: x -> K Encoding.Encoding pg

207278instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

208279instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

209−instance ToParam Word16 'PGint2 where toParam = K . Encoding.int2_word16

210280instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

211−instance ToParam Word32 'PGint4 where toParam = K . Encoding.int4_word32

212281instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

213−instance ToParam Word64 'PGint8 where toParam = K . Encoding.int8_word64

282+instance ToParam Oid 'PGoid where toParam = K . Encoding.int4_word32 . getOid

214283instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

215284instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

216285instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric

286+instance ToParam Money 'PGmoney where toParam = K . Encoding.int8_int64 . cents

217287instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

218288instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

219289instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

220290instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict

221291instance 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

222294instance ToParam Strict.ByteString 'PGbytea where

223295 toParam = K . Encoding.bytea_strict

224296instance ToParam Lazy.ByteString 'PGbytea where

@@ -232,17 +304,40 @@ instance ToParam LocalTime 'PGtimestamp where

232304instance ToParam UTCTime 'PGtimestamptz where

233305 toParam = K . Encoding.timestamptz_int

234306instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int

235−instance ToParam Value 'PGjson where toParam = K . Encoding.json_ast

236−instance ToParam Value 'PGjsonb where toParam = K . Encoding.jsonb_ast

237−instance (HasOid pg, ToParam x pg)

238− => ToParam (Vector (Maybe x)) ('PGvararray pg) where

239− toParam = K . Encoding.nullableArray_vector

240− (oid @pg) (unK . toParam @x @pg)

307+instance ToParam Aeson.Value 'PGjson where toParam = K . Encoding.json_ast

308+instance ToParam Aeson.Value 'PGjsonb where toParam = K . Encoding.jsonb_ast

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)

327+ => ToParam (VarArray (Vector (Maybe x))) ('PGvararray ('Null pg)) where

328+ toParam = K

329+ . Encoding.nullableArray_vector

330+ (getOid (oidOf @pg)) (unK . toParam @x @pg)

331+ . getVarArray

332+instance (ToFixArray x dims ty, ty ~ nullity pg, OidOf pg)

333+ => ToParam (FixArray x) ('PGfixarray dims ty) where

334+ toParam = K . Encoding.array (getOid (oidOf @pg))

335+ . unK . unK . toFixArray @x @dims @ty . getFixArray

241336instance

242337 ( IsEnumType x

243338 , HasDatatypeInfo x

244− , LabelsFrom x ~ labels

245− ) => ToParam x ('PGenum labels) where

339+ , LabelsPG x ~ labels

340+ ) => ToParam (Enumerated x) ('PGenum labels) where

246341 toParam =

247342 let

248343 gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String

@@ -253,24 +348,23 @@ instance

253348 gshowConstructor constructors (SOP xs)

254349 in

255350 K . Encoding.text_strict

256− . Strict.pack

351+ . Strict.Text.pack

257352 . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))

258353 . from

354+ . getEnumerated

259355instance

260356 ( SListI fields

261− , MapMaybes xs

262− , IsProductType x (Maybes xs)

263− , AllZip ToAliasedParam xs fields

264− , FieldNamesFrom x ~ AliasesOf fields

265− , All HasAliasedOid fields

266− ) => ToParam x ('PGcomposite fields) where

357+ , IsRecord x xs

358+ , AllZip ToField xs fields

359+ , All OidOfField fields

360+ ) => ToParam (Composite x) ('PGcomposite fields) where

267361 toParam =

268362 let

269363

270− encoders = htrans (Proxy @ToAliasedParam) toAliasedParam

364+ encoders = htrans (Proxy @ToField) toField

271365

272366 composite

273− :: All HasAliasedOid row

367+ :: All OidOfField row

274368 => NP (K (Maybe Encoding.Encoding)) row

275369 -> K Encoding.Encoding ('PGcomposite row)

276370 composite fields = K $

@@ -287,53 +381,179 @@ instance

287381 int32BE (fromIntegral (lengthSList (Proxy @xs))) <>

288382 let

289383 each

290− :: HasAliasedOid field

384+ :: OidOfField field

291385 => K (Maybe Encoding.Encoding) field

292386 -> Encoding.Encoding

293387 each (K field :: K (Maybe Encoding.Encoding) field) =

294− word32BE (aliasedOid @field)

388+ word32BE (getOid (oidOfField @field))

295389 <> case field of

296390 Nothing -> int64BE (-1)

297391 Just value ->

298392 int32BE (fromIntegral (builderLength value))

299393 <> value

300394 in

301− hcfoldMap (Proxy @HasAliasedOid) each fields

395+ hcfoldMap (Proxy @OidOfField) each fields

302396

303397 in

304− composite . encoders . unMaybes . unZ . unSOP . from

305−

306−class HasAliasedOid (field :: (Symbol, PGType)) where aliasedOid :: Word32

307−instance HasOid ty => HasAliasedOid (alias ::: ty) where aliasedOid = oid @ty

308−

309−class ToAliasedParam (x :: Type) (field :: (Symbol, PGType)) where

310− toAliasedParam :: Maybe x -> K (Maybe Encoding.Encoding) field

311−instance ToParam x ty => ToAliasedParam x (alias ::: ty) where

312− toAliasedParam = \case

313− Nothing -> K Nothing

314− Just x -> K . Just . unK $ toParam @x @ty x

315−

316−-- | A `ToColumnParam` constraint lifts the `ToParam` encoding

317−-- of a `Type` to a `NullityType`, encoding `Maybe`s to `Null`s. You should

318−-- not define instances of `ToColumnParam`, just use the provided instances.

319−class ToColumnParam (x :: Type) (ty :: NullityType) where

320− -- | >>> toColumnParam @Int16 @('NotNull 'PGint2) 0

321− -- K (Just "\NUL\NUL")

322− --

323− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) (Just 0)

324− -- K (Just "\NUL\NUL")

325− --

326− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) Nothing

327− -- K Nothing

328− toColumnParam :: x -> K (Maybe Strict.ByteString) ty

329−instance ToParam x pg => ToColumnParam x ('NotNull pg) where

330− toColumnParam = K . Just . Encoding.encodingBytes . unK . toParam @x @pg

331−instance ToParam x pg => ToColumnParam (Maybe x) ('Null pg) where

332− toColumnParam = K . fmap (Encoding.encodingBytes . unK . toParam @x @pg)

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

522+instance ToParam x pg => ToNullityParam x ('NotNull pg) where

523+ toNullityParam = K . Just . unK . toParam @x @pg

524+instance ToParam x pg => ToNullityParam (Maybe x) ('Null pg) where

525+ toNullityParam = K . fmap (unK . toParam @x @pg)

526+

527+-- | A `ToField` constraint lifts the `ToParam` parser

528+-- to an encoding of a @(Symbol, Type)@ to a @(Symbol, NullityType)@,

529+-- encoding `Null`s to `Maybe`s. You should not define instances for

530+-- `FromField`, just use the provided instances.

531+class ToField (x :: (Symbol, Type)) (field :: (Symbol, NullityType)) where

532+ toField :: P x -> K (Maybe Encoding.Encoding) field

533+instance ToNullityParam x ty => ToField (alias ::: x) (alias ::: ty) where

534+ toField (P x) = K . unK $ toNullityParam @x @ty x

535+

536+-- | A `ToFixArray` constraint gives an encoding of a Haskell `Type`

537+-- into the binary format of a PostgreSQL fixed-length array.

538+-- You should not define instances for

539+-- `ToFixArray`, just use the provided instances.

540+class ToFixArray (x :: Type) (dims :: [Nat]) (array :: NullityType) where

541+ toFixArray :: x -> K (K Encoding.Array dims) array

542+instance ToNullityParam x ty => ToFixArray x '[] ty where

543+ toFixArray = K . K . maybe Encoding.nullArray Encoding.encodingArray . unK

544+ . toNullityParam @x @ty

545+instance

546+ ( IsProductType product xs

547+ , Length xs ~ dim

548+ , All ((~) x) xs

549+ , ToFixArray x dims ty )

550+ => ToFixArray product (dim ': dims) ty where

551+ toFixArray = K . K . Encoding.dimensionArray foldlN

552+ (unK . unK . toFixArray @x @dims @ty) . unZ . unSOP . from

333553

334554-- | A `ToParams` constraint generically sequences the encodings of `Type`s

335555-- of the fields of a tuple or record to a row of `ColumnType`s. You should

336−-- not define instances of `ToParams`. Instead define `Generic` instances

556+-- not define instances of `ToParams`. Instead define `SOP.Generic` instances

337557-- which in turn provide `ToParams` instances.

338558class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

339559 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]

@@ -345,61 +565,98 @@ class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

345565 -- >>> instance Generic Tuple

346566 -- >>> toParams @Tuple @Params (Tuple False (Just 0))

347567 -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil

348− toParams :: x -> NP (K (Maybe Strict.ByteString)) tys

349−instance (SListI tys, IsProductType x xs, AllZip ToColumnParam xs tys)

568+ toParams :: x -> NP (K (Maybe Encoding.Encoding)) tys

569+instance (SListI tys, IsProductType x xs, AllZip ToNullityParam xs tys)

350570 => ToParams x tys where

351571 toParams

352− = htrans (Proxy @ToColumnParam) (toColumnParam . unI)

572+ = htrans (Proxy @ToNullityParam) (toNullityParam . unI)

353573 . unZ . unSOP . from

354574

355575-- | A `FromValue` constraint gives a parser from the binary format of

356576-- a PostgreSQL `PGType` into a Haskell `Type`.

357577class FromValue (pg :: PGType) (y :: Type) where

358578 -- | >>> newtype Id = Id { getId :: Int16 } deriving Show

359− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue

360− fromValue :: proxy pg -> Decoding.Value y

361−instance FromValue 'PGbool Bool where fromValue _ = Decoding.bool

362−instance FromValue 'PGint2 Int16 where fromValue _ = Decoding.int

363−instance FromValue 'PGint4 Int32 where fromValue _ = Decoding.int

364−instance FromValue 'PGint8 Int64 where fromValue _ = Decoding.int

365−instance FromValue 'PGfloat4 Float where fromValue _ = Decoding.float4

366−instance FromValue 'PGfloat8 Double where fromValue _ = Decoding.float8

367−instance FromValue 'PGnumeric Scientific where fromValue _ = Decoding.numeric

368−instance FromValue 'PGuuid UUID where fromValue _ = Decoding.uuid

369−instance FromValue 'PGinet (NetAddr IP) where fromValue _ = Decoding.inet

370−instance FromValue ('PGchar 1) Char where fromValue _ = Decoding.char

371−instance FromValue 'PGtext Strict.Text where fromValue _ = Decoding.text_strict

372−instance FromValue 'PGtext Lazy.Text where fromValue _ = Decoding.text_lazy

579+ -- >>> instance FromValue 'PGint2 Id where fromValue = Id <$> fromValue @'PGint2

580+ fromValue :: Decoding.Value y

581+instance FromValue 'PGbool Bool where fromValue = Decoding.bool

582+instance FromValue 'PGint2 Int16 where fromValue = Decoding.int

583+instance FromValue 'PGint4 Int32 where fromValue = Decoding.int

584+instance FromValue 'PGint8 Int64 where fromValue = Decoding.int

585+instance FromValue 'PGoid Word32 where fromValue = Decoding.int

586+instance FromValue 'PGfloat4 Float where fromValue = Decoding.float4

587+instance FromValue 'PGfloat8 Double where fromValue = Decoding.float8

588+instance FromValue 'PGnumeric Scientific where fromValue = Decoding.numeric

589+instance FromValue 'PGmoney Money where fromValue = Money <$> Decoding.int

590+instance FromValue 'PGuuid UUID where fromValue = Decoding.uuid

591+instance FromValue 'PGinet (NetAddr IP) where fromValue = Decoding.inet

592+instance FromValue ('PGchar 1) Char where fromValue = Decoding.char

593+instance FromValue 'PGtext Strict.Text where fromValue = Decoding.text_strict

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

373597instance FromValue 'PGbytea Strict.ByteString where

374− fromValue _ = Decoding.bytea_strict

598+ fromValue = Decoding.bytea_strict

375599instance FromValue 'PGbytea Lazy.ByteString where

376− fromValue _ = Decoding.bytea_lazy

377−instance FromValue 'PGdate Day where fromValue _ = Decoding.date

378−instance FromValue 'PGtime TimeOfDay where fromValue _ = Decoding.time_int

600+ fromValue = Decoding.bytea_lazy

601+instance FromValue 'PGdate Day where fromValue = Decoding.date

602+instance FromValue 'PGtime TimeOfDay where fromValue = Decoding.time_int

379603instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where

380− fromValue _ = Decoding.timetz_int

604+ fromValue = Decoding.timetz_int

381605instance FromValue 'PGtimestamp LocalTime where

382− fromValue _ = Decoding.timestamp_int

606+ fromValue = Decoding.timestamp_int

383607instance FromValue 'PGtimestamptz UTCTime where

384− fromValue _ = Decoding.timestamptz_int

608+ fromValue = Decoding.timestamptz_int

385609instance FromValue 'PGinterval DiffTime where

386− fromValue _ = Decoding.interval_int

387−instance FromValue 'PGjson Value where fromValue _ = Decoding.json_ast

388−instance FromValue 'PGjsonb Value where fromValue _ = Decoding.jsonb_ast

389−instance FromValue pg y => FromValue ('PGvararray pg) (Vector (Maybe y)) where

390− fromValue _ = Decoding.array

391− (Decoding.dimensionArray Vector.replicateM

392− (Decoding.nullableValueArray (fromValue (Proxy @pg))))

393−instance FromValue pg y => FromValue ('PGfixarray n pg) (Vector (Maybe y)) where

394− fromValue _ = Decoding.array

395− (Decoding.dimensionArray Vector.replicateM

396− (Decoding.nullableValueArray (fromValue (Proxy @pg))))

610+ fromValue = Decoding.interval_int

611+instance FromValue 'PGjson Aeson.Value where fromValue = Decoding.json_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

620+ => FromValue ('PGvararray ('NotNull pg)) (VarArray (Vector y)) where

621+ fromValue =

622+ let

623+ rep n x = VarArray <$> Vector.replicateM n x

624+ in

625+ Decoding.array $ Decoding.dimensionArray rep

626+ (fromFixArray @'[] @('NotNull pg))

627+instance FromValue pg y

628+ => FromValue ('PGvararray ('Null pg)) (VarArray (Vector (Maybe y))) where

629+ fromValue =

630+ let

631+ rep n x = VarArray <$> Vector.replicateM n x

632+ in

633+ Decoding.array $ Decoding.dimensionArray rep

634+ (fromFixArray @'[] @('Null pg))

635+instance FromValue pg y

636+ => FromValue ('PGvararray ('NotNull pg)) (VarArray [y]) where

637+ fromValue =

638+ let

639+ rep n x = VarArray <$> replicateM n x

640+ in

641+ Decoding.array $ Decoding.dimensionArray rep

642+ (fromFixArray @'[] @('NotNull pg))

643+instance FromValue pg y

644+ => FromValue ('PGvararray ('Null pg)) (VarArray [Maybe y]) where

645+ fromValue =

646+ let

647+ rep n x = VarArray <$> replicateM n x

648+ in

649+ Decoding.array $ Decoding.dimensionArray rep

650+ (fromFixArray @'[] @('Null pg))

651+instance FromFixArray dims ty y

652+ => FromValue ('PGfixarray dims ty) (FixArray y) where

653+ fromValue = FixArray <$> Decoding.array (fromFixArray @dims @ty @y)

397654instance

398655 ( IsEnumType y

399656 , HasDatatypeInfo y

400− , LabelsFrom y ~ labels

401− ) => FromValue ('PGenum labels) y where

402− fromValue _ =

657+ , LabelsPG y ~ labels

658+ ) => FromValue ('PGenum labels) (Enumerated y) where

659+ fromValue =

403660 let

404661 greadConstructor

405662 :: All ((~) '[]) xss

@@ -412,29 +669,16 @@ instance

412669 then Just (SOP (Z Nil))

413670 else SOP . S . unSOP <$> greadConstructor constructors name

414671 in

415− Decoding.enum

672+ fmap Enumerated

673+ . Decoding.enum

416674 $ fmap to

417675 . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))

418− . Strict.unpack

419−

676+ . Strict.Text.unpack

420677instance

421− ( SListI fields

422− , MapMaybes ys

423− , IsProductType y (Maybes ys)

424− , AllZip FromAliasedValue fields ys

425− , FieldNamesFrom y ~ AliasesOf fields

426− ) => FromValue ('PGcomposite fields) y where

678+ ( FromRow fields y

679+ ) => FromValue ('PGcomposite fields) (Composite y) where

427680 fromValue =

428681 let

429− decoders

430− :: forall pgs zs proxy

431− . AllZip FromAliasedValue pgs zs

432− => proxy ('PGcomposite pgs)

433− -> NP Decoding.Value zs

434− decoders _ = htrans (Proxy @FromAliasedValue) fromAliasedValue

435− (hpure Proxy :: NP Proxy pgs)

436−

437− composite fields = do

438682 -- <number of fields: 4 bytes>

439683 -- [for each field]

440684 -- <OID of field's type: sizeof(Oid) bytes>

@@ -445,80 +689,133 @@ instance

445689 -- <value: <length> bytes>

446690 -- [end if]

447691 -- [end for]

692+ composite = Decoding.valueParser $ do

448693 unitOfSize 4

449− let

450− each field = do

451− unitOfSize 4

452− len <- sized 4 Decoding.int

453− if len == -1 then return Nothing else Just <$> sized len field

454− htraverse' each fields

455−

456− in fmap (to . SOP . Z . maybes) . composite . decoders

457−

458−class FromAliasedValue (pg :: (Symbol,PGType)) (y :: Type) where

459− fromAliasedValue :: proxy pg -> Decoding.Value y

460−instance FromValue pg y => FromAliasedValue (alias ::: pg) y where

461− fromAliasedValue _ = fromValue (Proxy @pg)

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))

462702

463−-- | A `FromColumnValue` constraint lifts the `FromValue` parser

703+-- | A `FromField` constraint lifts the `FromValue` parser

464704-- to a decoding of a @(Symbol, NullityType)@ to a `Type`,

465705-- decoding `Null`s to `Maybe`s. You should not define instances for

466−-- `FromColumnValue`, just use the provided instances.

467−class FromColumnValue (colty :: (Symbol,NullityType)) (y :: Type) where

468− -- | >>> :set -XTypeOperators -XOverloadedStrings

469− -- >>> newtype Id = Id { getId :: Int16 } deriving Show

470− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue

471− -- >>> fromColumnValue @("col" ::: 'NotNull 'PGint2) @Id (K (Just "\NUL\SOH"))

472− -- Id {getId = 1}

473− --

474− -- >>> fromColumnValue @("col" ::: 'Null 'PGint2) @(Maybe Id) (K (Just "\NUL\SOH"))

475− -- Just (Id {getId = 1})

476− fromColumnValue :: K (Maybe Strict.ByteString) colty -> y

706+-- `FromField`, just use the provided instances.

707+class FromField (pg :: (Symbol, NullityType)) (y :: (Symbol, Type)) where

708+ fromField

709+ :: K (Maybe Strict.ByteString) pg

710+ -> (Either Strict.Text :.: P) y

477711instance FromValue pg y

478− => FromColumnValue (column ::: ('NotNull pg)) y where

479− fromColumnValue = \case

480− K Nothing -> error "fromColumnValue: saw NULL when expecting NOT NULL"

481− K (Just bs) ->

482− let

483− errOrValue =

484− Decoding.valueParser (fromValue @pg @y Proxy) bs

485− err str = error $ "fromColumnValue: " ++ Strict.unpack str

486− in

487− either err id errOrValue

712+ => FromField (column ::: ('NotNull pg)) (column ::: y) where

713+ fromField = Comp . \case

714+ K Nothing -> Left "fromField: saw NULL when expecting NOT NULL"

715+ K (Just bytestring) -> P <$>

716+ Decoding.valueParser (fromValue @pg) bytestring

488717instance FromValue pg y

489− => FromColumnValue (column ::: ('Null pg)) (Maybe y) where

490− fromColumnValue (K nullOrBytes)

491− = either err id

492− . Decoding.valueParser (fromValue @pg @y Proxy)

493− <$> nullOrBytes

494− where

495− err str = error $ "fromColumnValue: " ++ Strict.unpack str

718+ => FromField (column ::: 'Null pg) (column ::: Maybe y) where

719+ fromField = Comp . \case

720+ K Nothing -> Right $ P Nothing

721+ K (Just bytestring) -> P . Just <$>

722+ Decoding.valueParser (fromValue @pg) bytestring

723+

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)

496745

497746-- | A `FromRow` constraint generically sequences the parsings of the columns

498−-- of a `RelationType` into the fields of a record `Type` provided they have

747+-- of a `RowType` into the fields of a record `Type` provided they have

499748-- the same field names. You should not define instances of `FromRow`.

500−-- Instead define `Generic` and `HasDatatypeInfo` instances which in turn

749+-- Instead define `SOP.Generic` and `SOP.HasDatatypeInfo` instances which in turn

501750-- provide `FromRow` instances.

502−class SListI results => FromRow (results :: RelationType) y where

751+class SListI result => FromRow (result :: RowType) y where

503752 -- | >>> :set -XOverloadedStrings

504753 -- >>> import Data.Text

505754 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show

506− -- >>> instance FromValue 'PGint2 UserId where fromValue = fmap UserId . fromValue

755+ -- >>> instance FromValue 'PGint2 UserId where fromValue = UserId <$> fromValue @'PGint2

507756 -- >>> data UserRow = UserRow { userId :: UserId, userName :: Maybe Text } deriving (Show, GHC.Generic)

508757 -- >>> instance Generic UserRow

509758 -- >>> instance HasDatatypeInfo UserRow

510759 -- >>> type User = '["userId" ::: 'NotNull 'PGint2, "userName" ::: 'Null 'PGtext]

511760 -- >>> fromRow @User @UserRow (K (Just "\NUL\SOH") :* K (Just "bloodninja") :* Nil)

512− -- UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"}

513− fromRow :: NP (K (Maybe Strict.ByteString)) results -> y

761+ -- Right (UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"})

762+ fromRow :: NP (K (Maybe Strict.ByteString)) result -> Either Strict.Text y

514763instance

515− ( SListI results

516− , IsProductType y ys

517− , AllZip FromColumnValue results ys

518− , FieldNamesFrom y ~ AliasesOf results

519− ) => FromRow results y where

764+ ( SListI result

765+ , IsRecord y ys

766+ , AllZip FromField result ys

767+ ) => FromRow result y where

520768 fromRow

521− = to . SOP . Z . htrans (Proxy @FromColumnValue) (I . fromColumnValue)

769+ = fmap fromRecord

770+ . hsequence'

771+ . htrans (Proxy @FromField) fromField

772+------------------------------------------------------

773+-- P records

774+------------------------------------------------------

775+-- instance (FromField (col ::: pg) (col ::: hask))

776+-- => FromRow '[col ::: pg] (P (col ::: hask)) where

777+-- fromRow (pg :* Nil) = (unComp . fromField) pg

778+-- instance

779+-- ( row ~ Join row1 row2

780+-- , FromRow row1 hask1

781+-- , FromRow row2 hask2

782+-- , SListI row

783+-- ) => FromRow row (hask1, hask2) where

784+-- fromRow row = case disjoin @row1 @row2 row of

785+-- (row1, row2) -> (,) <$> fromRow row1 <*> fromRow row2

786+-- instance

787+-- ( row ~ Join row1 row23

788+-- , FromRow row1 hask1

789+-- , FromRow row23 (hask2, hask3)

790+-- , SListI row

791+-- ) => FromRow row (hask1, hask2, hask3) where

792+-- fromRow row = case disjoin @row1 @row23 row of

793+-- (row1, row23) -> do

794+-- hask1 <- fromRow row1

795+-- (hask2, hask3) <- fromRow row23

796+-- return (hask1, hask2, hask3)

797+-- instance

798+-- ( row ~ Join row1 row234

799+-- , FromRow row1 hask1

800+-- , FromRow row234 (hask2, hask3, hask4)

801+-- , SListI row

802+-- ) => FromRow row (hask1, hask2, hask3, hask4) where

803+-- fromRow row = case disjoin @row1 @row234 row of

804+-- (row1, row234) -> do

805+-- hask1 <- fromRow row1

806+-- (hask2, hask3, hask4) <- fromRow row234

807+-- return (hask1, hask2, hask3, hask4)

808+-- instance

809+-- ( row ~ Join row1 row2345

810+-- , FromRow row1 hask1

811+-- , FromRow row2345 (hask2, hask3, hask4, hask5)

812+-- , SListI row

813+-- ) => FromRow row (hask1, hask2, hask3, hask4, hask5) where

814+-- fromRow row = case disjoin @row1 @row2345 row of

815+-- (row1, row2345) -> do

816+-- hask1 <- fromRow row1

817+-- (hask2, hask3, hask4, hask5) <- fromRow row2345

818+-- return (hask1, hask2, hask3, hask4, hask5)

522819

523820-- | `Only` is a 1-tuple type, useful for encoding a single parameter with

524821-- `toParams` or decoding a single value with `fromRow`.

@@ -528,8 +825,24 @@ instance

528825-- K (Just "foo") :* Nil

529826--

530827-- >>> fromRow @'["fromOnly" ::: 'Null 'PGtext] @(Only (Maybe Text)) (K (Just "bar") :* Nil)

531−-- Only {fromOnly = Just "bar"}

828+-- Right (Only {fromOnly = Just "bar"})

532829newtype Only x = Only { fromOnly :: x }

533830 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)

534831instance Generic (Only x)

535832instance HasDatatypeInfo (Only x)

833+

834+foldlN

835+ :: All ((~) x) xs

836+ => (z -> x -> z) -> z -> NP I xs -> z

837+foldlN f z = \case

838+ Nil -> z

839+ I x :* xs -> let z' = f z x in seq z' $ foldlN f z' xs

840+

841+replicateMN

842+ :: forall x xs m. (All ((~) x) xs, Monad m, SListI xs)

843+ => m x -> m (NP I xs)

844+replicateMN mx = hsequence' $

845+ hcpure (Proxy :: Proxy ((~) x)) (Comp (I <$> mx))

846+

847+getOid :: LibPQ.Oid -> Word32

848+getOid (LibPQ.Oid (CUInt oid)) = oid

squeal-postgresql/src/Squeal/PostgreSQL/Definition.hs+23−893

@@ -11,13 +11,15 @@ Squeal data definition language.

1111{-# LANGUAGE

1212 AllowAmbiguousTypes

1313 , ConstraintKinds

14+ , DeriveAnyClass

1415 , DeriveGeneric

16+ , DerivingStrategies

1517 , FlexibleContexts

1618 , FlexibleInstances

1719 , GADTs

18− , GeneralizedNewtypeDeriving

1920 , LambdaCase

2021 , MultiParamTypeClasses

22+ , OverloadedLabels

2123 , OverloadedStrings

2224 , RankNTypes

2325 , ScopedTypeVariables

@@ -25,928 +27,56 @@ Squeal data definition language.

2527 , TypeInType

2628 , TypeOperators

2729 , UndecidableSuperClasses

30+ , UndecidableInstances

2831#-}

2932

3033module Squeal.PostgreSQL.Definition

3134 ( -- * Definition

32− Definition (UnsafeDefinition, renderDefinition)

35+ Definition (..)

3336 , (>>>)

34− -- * Tables

35− -- ** Create

36− , createTable

37− , createTableIfNotExists

38− , TableConstraintExpression (..)

39− , check

40− , unique

41− , primaryKey

42− , foreignKey

43− , ForeignKeyed

44− , OnDeleteClause (OnDeleteNoAction, OnDeleteRestrict, OnDeleteCascade)

45− , renderOnDeleteClause

46− , OnUpdateClause (OnUpdateNoAction, OnUpdateRestrict, OnUpdateCascade)

47− , renderOnUpdateClause

48− -- ** Drop

49− , dropTable

50− -- ** Alter

51− , alterTable

52− , alterTableRename

53− , AlterTable (UnsafeAlterTable, renderAlterTable)

54− , addConstraint

55− , dropConstraint

56− , AddColumn (addColumn)

57− , dropColumn

58− , renameColumn

59− , alterColumn

60− , AlterColumn (UnsafeAlterColumn, renderAlterColumn)

61− , setDefault

62− , dropDefault

63− , setNotNull

64− , dropNotNull

65− , alterType

66− -- * Views

67− , createView

68− , dropView

69− -- * Types

70− , createTypeEnum

71− , createTypeEnumFrom

72− , createTypeComposite

73− , createTypeCompositeFrom

74− , dropType

75− -- * Columns

76− , ColumnTypeExpression (..)

77− , nullable

78− , notNullable

79− , default_

80− , serial2

81− , smallserial

82− , serial4

83− , serial

84− , serial8

85− , bigserial

37+ , manipDefinition

8638 ) where

8739

8840import Control.Category

8941import Control.DeepSeq

9042import Data.ByteString

9143import Data.Monoid

92−import GHC.TypeLits

9344import Prelude hiding ((.), id)

9445

95−import qualified Generics.SOP as SOP

9646import qualified GHC.Generics as GHC

9747

98−import Squeal.PostgreSQL.Expression

99−import Squeal.PostgreSQL.Query

48+import Squeal.PostgreSQL.Manipulation

10049import Squeal.PostgreSQL.Render

10150import Squeal.PostgreSQL.Schema

10251

52+-- $setup

53+-- >>> import Squeal.PostgreSQL

54+

10355{-----------------------------------------

10456statements

10557-----------------------------------------}

10658

107−-- | A `Definition` is a statement that changes the schema of the

59+-- | A `Definition` is a statement that changes the schemas of the

10860-- database, like a `createTable`, `dropTable`, or `alterTable` command.

10961-- `Definition`s may be composed using the `>>>` operator.

11062newtype Definition

111− (schema0 :: SchemaType)

112− (schema1 :: SchemaType)

63+ (schemas0 :: SchemasType)

64+ (schemas1 :: SchemasType)

11365 = UnsafeDefinition { renderDefinition :: ByteString }

11466 deriving (GHC.Generic,Show,Eq,Ord,NFData)

11567

116−instance RenderSQL (Definition schema0 schema1) where

68+instance RenderSQL (Definition schemas0 schemas1) where

11769 renderSQL = renderDefinition

11870

11971instance Category Definition where

12072 id = UnsafeDefinition ";"

12173 ddl1 . ddl0 = UnsafeDefinition $

122− renderDefinition ddl0 <> "\n" <> renderDefinition ddl1

123−

124−{-----------------------------------------

125−CREATE statements

126−-----------------------------------------}

127−

128−{- | `createTable` adds a table to the schema.

129−

130−>>> :set -XOverloadedLabels

131−>>> :{

132−printSQL $

133− createTable #tab ((int & nullable) `As` #a :* (real & nullable) `As` #b :* Nil) Nil

134−:}

135−CREATE TABLE "tab" ("a" int NULL, "b" real NULL);

136−-}

137−createTable

138− :: ( KnownSymbol table

139− , columns ~ (col ': cols)

140− , SOP.SListI columns

141− , SOP.SListI constraints

142− , schema1 ~ Create table ('Table (constraints :=> columns)) schema0 )

143− => Alias table -- ^ the name of the table to add

144− -> NP (Aliased (ColumnTypeExpression schema0)) columns

145− -- ^ the names and datatype of each column

146− -> NP (Aliased (TableConstraintExpression schema1 table)) constraints

147− -- ^ constraints that must hold for the table

148− -> Definition schema0 schema1

149−createTable tab columns constraints = UnsafeDefinition $

150− "CREATE TABLE" <+> renderCreation tab columns constraints

151−

152−{-| `createTableIfNotExists` creates a table if it doesn't exist, but does not add it to the schema.

153−Instead, the schema already has the table so if the table did not yet exist, the schema was wrong.

154−`createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in

155−the `Category` of `Definition`s.

156−

157−>>> :set -XOverloadedLabels -XTypeApplications

158−>>> type Table = '[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGfloat4]

159−>>> type Schema = '["tab" ::: 'Table Table]

160−>>> :{

161−let

162− setup :: Definition Schema Schema

163− setup = createTableIfNotExists #tab ((int & nullable) `As` #a :* (real & nullable) `As` #b :* Nil) Nil

164−in printSQL setup

165−:}

166−CREATE TABLE IF NOT EXISTS "tab" ("a" int NULL, "b" real NULL);

167−-}

168−createTableIfNotExists

169− :: ( Has table schema ('Table (constraints :=> columns))

170− , SOP.SListI columns

171− , SOP.SListI constraints )

172− => Alias table -- ^ the name of the table to add

173− -> NP (Aliased (ColumnTypeExpression schema)) columns

174− -- ^ the names and datatype of each column

175− -> NP (Aliased (TableConstraintExpression schema table)) constraints

176− -- ^ constraints that must hold for the table

177− -> Definition schema schema

178−createTableIfNotExists tab columns constraints = UnsafeDefinition $

179− "CREATE TABLE IF NOT EXISTS"

180− <+> renderCreation tab columns constraints

181−

182−-- helper function for `createTable` and `createTableIfNotExists`

183−renderCreation

184− :: ( KnownSymbol table

185− , SOP.SListI columns

186− , SOP.SListI constraints )

187− => Alias table -- ^ the name of the table to add

188− -> NP (Aliased (ColumnTypeExpression schema0)) columns

189− -- ^ the names and datatype of each column

190− -> NP (Aliased (TableConstraintExpression schema1 table)) constraints

191− -- ^ constraints that must hold for the table

192− -> ByteString

193−renderCreation tab columns constraints = renderAlias tab

194− <+> parenthesized

195− ( renderCommaSeparated renderColumnDef columns

196− <> ( case constraints of

197− Nil -> ""

198− _ -> ", " <>

199− renderCommaSeparated renderConstraint constraints ) )

200− <> ";"

201− where

202− renderColumnDef :: Aliased (ColumnTypeExpression schema) x -> ByteString

203− renderColumnDef (ty `As` column) =

204− renderAlias column <+> renderColumnTypeExpression ty

205− renderConstraint

206− :: Aliased (TableConstraintExpression schema columns) constraint

207− -> ByteString

208− renderConstraint (constraint `As` alias) =

209− "CONSTRAINT" <+> renderAlias alias <+> renderTableConstraintExpression constraint

210−

211−-- | Data types are a way to limit the kind of data that can be stored in a

212−-- table. For many applications, however, the constraint they provide is

213−-- too coarse. For example, a column containing a product price should

214−-- probably only accept positive values. But there is no standard data type

215−-- that accepts only positive numbers. Another issue is that you might want

216−-- to constrain column data with respect to other columns or rows.

217−-- For example, in a table containing product information,

218−-- there should be only one row for each product number.

219−-- `TableConstraint`s give you as much control over the data in your tables

220−-- as you wish. If a user attempts to store data in a column that would

221−-- violate a constraint, an error is raised. This applies

222−-- even if the value came from the default value definition.

223−newtype TableConstraintExpression

224− (schema :: SchemaType)

225− (table :: Symbol)

226− (tableConstraint :: TableConstraint)

227− = UnsafeTableConstraintExpression

228− { renderTableConstraintExpression :: ByteString }

229− deriving (GHC.Generic,Show,Eq,Ord,NFData)

230−

231−{-| A `check` constraint is the most generic `TableConstraint` type.

232−It allows you to specify that the value in a certain column must satisfy

233−a Boolean (truth-value) expression.

234−

235−>>> :{

236−type Schema = '[

237− "tab" ::: 'Table ('[ "inequality" ::: 'Check '["a","b"]] :=> '[

238− "a" ::: 'NoDef :=> 'NotNull 'PGint4,

239− "b" ::: 'NoDef :=> 'NotNull 'PGint4

240− ])]

241−:}

242−

243−>>> :{

244−let

245− definition :: Definition '[] Schema

246− definition = createTable #tab

247− ( (int & notNullable) `As` #a :*

248− (int & notNullable) `As` #b :* Nil )

249− ( check (#a :* #b :* Nil) (#a .> #b) `As` #inequality :* Nil )

250−:}

251−

252−>>> printSQL definition

253−CREATE TABLE "tab" ("a" int NOT NULL, "b" int NOT NULL, CONSTRAINT "inequality" CHECK (("a" > "b")));

254−-}

255−check

256− :: ( Has alias schema ('Table table)

257− , HasAll aliases (TableToRelation table) subcolumns )

258− => NP Alias aliases

259− -- ^ specify the subcolumns which are getting checked

260− -> (forall tab. Condition schema '[tab ::: subcolumns] 'Ungrouped '[])

261− -- ^ a closed `Condition` on those subcolumns

262− -> TableConstraintExpression schema alias ('Check aliases)

263−check _cols condition = UnsafeTableConstraintExpression $

264− "CHECK" <+> parenthesized (renderExpression condition)

265−

266−{-| A `unique` constraint ensure that the data contained in a column,

267−or a group of columns, is unique among all the rows in the table.

268−

269−>>> :{

270−type Schema = '[

271− "tab" ::: 'Table( '[ "uq_a_b" ::: 'Unique '["a","b"]] :=> '[

272− "a" ::: 'NoDef :=> 'Null 'PGint4,

273− "b" ::: 'NoDef :=> 'Null 'PGint4

274− ])]

275−:}

276−

277−>>> :{

278−let

279− definition :: Definition '[] Schema

280− definition = createTable #tab

281− ( (int & nullable) `As` #a :*

282− (int & nullable) `As` #b :* Nil )

283− ( unique (#a :* #b :* Nil) `As` #uq_a_b :* Nil )

284−:}

285−

286−>>> printSQL definition

287−CREATE TABLE "tab" ("a" int NULL, "b" int NULL, CONSTRAINT "uq_a_b" UNIQUE ("a", "b"));

288−-}

289−unique

290− :: ( Has alias schema ('Table table)

291− , HasAll aliases (TableToRelation table) subcolumns )

292− => NP Alias aliases

293− -- ^ specify subcolumns which together are unique for each row

294− -> TableConstraintExpression schema alias ('Unique aliases)

295−unique columns = UnsafeTableConstraintExpression $

296− "UNIQUE" <+> parenthesized (commaSeparated (renderAliases columns))

297−

298−{-| A `primaryKey` constraint indicates that a column, or group of columns,

299−can be used as a unique identifier for rows in the table.

300−This requires that the values be both unique and not null.

301−

302−>>> :{

303−type Schema = '[

304− "tab" ::: 'Table ('[ "pk_id" ::: 'PrimaryKey '["id"]] :=> '[

305− "id" ::: 'Def :=> 'NotNull 'PGint4,

306− "name" ::: 'NoDef :=> 'NotNull 'PGtext

307− ])]

308−:}

309−

310−>>> :{

311−let

312− definition :: Definition '[] Schema

313− definition = createTable #tab

314− ( serial `As` #id :*

315− (text & notNullable) `As` #name :* Nil )

316− ( primaryKey #id `As` #pk_id :* Nil )

317−:}

318−

319−>>> printSQL definition

320−CREATE TABLE "tab" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_id" PRIMARY KEY ("id"));

321−-}

322−primaryKey

323− :: ( Has alias schema ('Table table)

324− , HasAll aliases (TableToColumns table) subcolumns

325− , AllNotNull subcolumns )

326− => NP Alias aliases

327− -- ^ specify the subcolumns which together form a primary key.

328− -> TableConstraintExpression schema alias ('PrimaryKey aliases)

329−primaryKey columns = UnsafeTableConstraintExpression $

330− "PRIMARY KEY" <+> parenthesized (commaSeparated (renderAliases columns))

331−

332−{-| A `foreignKey` specifies that the values in a column

333−(or a group of columns) must match the values appearing in some row of

334−another table. We say this maintains the referential integrity

335−between two related tables.

336−

337−>>> :{

338−type Schema =

339− '[ "users" ::: 'Table (

340− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

341− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

342− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

343− ])

344− , "emails" ::: 'Table (

345− '[ "pk_emails" ::: 'PrimaryKey '["id"]

346− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

347− ] :=>

348− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

349− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

350− , "email" ::: 'NoDef :=> 'Null 'PGtext

351− ])

352− ]

353−:}

354−

355−>>> :{

356−let

357− setup :: Definition '[] Schema

358− setup =

359− createTable #users

360− ( serial `As` #id :*

361− (text & notNullable) `As` #name :* Nil )

362− ( primaryKey #id `As` #pk_users :* Nil ) >>>

363− createTable #emails

364− ( serial `As` #id :*

365− (int & notNullable) `As` #user_id :*

366− (text & nullable) `As` #email :* Nil )

367− ( primaryKey #id `As` #pk_emails :*

368− foreignKey #user_id #users #id

369− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

370−in printSQL setup

371−:}

372−CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));

373−CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

374−

375−A `foreignKey` can even be a table self-reference.

376−

377−>>> :{

378−type Schema =

379− '[ "employees" ::: 'Table (

380− '[ "employees_pk" ::: 'PrimaryKey '["id"]

381− , "employees_employer_fk" ::: 'ForeignKey '["employer_id"] "employees" '["id"]

382− ] :=>

383− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

384− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

385− , "employer_id" ::: 'NoDef :=> 'Null 'PGint4

386− ])

387− ]

388−:}

389−

390−>>> :{

391−let

392− setup :: Definition '[] Schema

393− setup =

394− createTable #employees

395− ( serial `As` #id :*

396− (text & notNullable) `As` #name :*

397− (integer & nullable) `As` #employer_id :* Nil )

398− ( primaryKey #id `As` #employees_pk :*

399− foreignKey #employer_id #employees #id

400− OnDeleteCascade OnUpdateCascade `As` #employees_employer_fk :* Nil )

401−in printSQL setup

402−:}

403−CREATE TABLE "employees" ("id" serial, "name" text NOT NULL, "employer_id" integer NULL, CONSTRAINT "employees_pk" PRIMARY KEY ("id"), CONSTRAINT "employees_employer_fk" FOREIGN KEY ("employer_id") REFERENCES "employees" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

404−-}

405−foreignKey

406− :: (ForeignKeyed schema child parent

407− table reftable

408− columns refcolumns

409− constraints cols

410− reftys tys )

411− => NP Alias columns

412− -- ^ column or columns in the table

413− -> Alias parent

414− -- ^ reference table

415− -> NP Alias refcolumns

416− -- ^ reference column or columns in the reference table

417− -> OnDeleteClause

418− -- ^ what to do when reference is deleted

419− -> OnUpdateClause

420− -- ^ what to do when reference is updated

421− -> TableConstraintExpression schema child

422− ('ForeignKey columns parent refcolumns)

423−foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $

424− "FOREIGN KEY" <+> parenthesized (commaSeparated (renderAliases keys))

425− <+> "REFERENCES" <+> renderAlias parent

426− <+> parenthesized (commaSeparated (renderAliases refs))

427− <+> renderOnDeleteClause ondel

428− <+> renderOnUpdateClause onupd

429−

430−-- | A constraint synonym between types involved in a foreign key constraint.

431−type ForeignKeyed schema

432− child parent

433− table reftable

434− columns refcolumns

435− constraints cols

436− reftys tys =

437− ( Has child schema ('Table table)

438− , Has parent schema ('Table reftable)

439− , HasAll columns (TableToColumns table) tys

440− , reftable ~ (constraints :=> cols)

441− , HasAll refcolumns cols reftys

442− , SOP.AllZip SamePGType tys reftys

443− , Uniquely refcolumns constraints )

444−

445−-- | `OnDeleteClause` indicates what to do with rows that reference a deleted row.

446−data OnDeleteClause

447− = OnDeleteNoAction

448− -- ^ if any referencing rows still exist when the constraint is checked,

449− -- an error is raised

450− | OnDeleteRestrict -- ^ prevents deletion of a referenced row

451− | OnDeleteCascade

452− -- ^ specifies that when a referenced row is deleted,

453− -- row(s) referencing it should be automatically deleted as well

454− deriving (GHC.Generic,Show,Eq,Ord)

455−instance NFData OnDeleteClause

456−

457−-- | Render `OnDeleteClause`.

458−renderOnDeleteClause :: OnDeleteClause -> ByteString

459−renderOnDeleteClause = \case

460− OnDeleteNoAction -> "ON DELETE NO ACTION"

461− OnDeleteRestrict -> "ON DELETE RESTRICT"

462− OnDeleteCascade -> "ON DELETE CASCADE"

463−

464−-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked

465−-- when a referenced column is changed (updated).

466−data OnUpdateClause

467− = OnUpdateNoAction

468− -- ^ if any referencing rows has not changed when the constraint is checked,

469− -- an error is raised

470− | OnUpdateRestrict -- ^ prevents update of a referenced row

471− | OnUpdateCascade

472− -- ^ the updated values of the referenced column(s) should be copied

473− -- into the referencing row(s)

474− deriving (GHC.Generic,Show,Eq,Ord)

475−instance NFData OnUpdateClause

476−

477−-- | Render `OnUpdateClause`.

478−renderOnUpdateClause :: OnUpdateClause -> ByteString

479−renderOnUpdateClause = \case

480− OnUpdateNoAction -> "ON UPDATE NO ACTION"

481− OnUpdateRestrict -> "ON UPDATE RESTRICT"

482− OnUpdateCascade -> "ON UPDATE CASCADE"

483−

484−{-----------------------------------------

485−DROP statements

486−-----------------------------------------}

487−

488−-- | `dropTable` removes a table from the schema.

489−--

490−-- >>> :{

491−-- let

492−-- definition :: Definition '["muh_table" ::: 'Table t] '[]

493−-- definition = dropTable #muh_table

494−-- :}

495−--

496−-- >>> printSQL definition

497−-- DROP TABLE "muh_table";

498−dropTable

499− :: Has table schema ('Table t)

500− => Alias table -- ^ table to remove

501− -> Definition schema (Drop table schema)

502−dropTable tab = UnsafeDefinition $ "DROP TABLE" <+> renderAlias tab <> ";"

503−

504−{-----------------------------------------

505−ALTER statements

506−-----------------------------------------}

507−

508−-- | `alterTable` changes the definition of a table from the schema.

509−alterTable

510− :: KnownSymbol alias

511− => Alias alias -- ^ table to alter

512− -> AlterTable alias table schema -- ^ alteration to perform

513− -> Definition schema (Alter alias ('Table table) schema)

514−alterTable tab alteration = UnsafeDefinition $

515− "ALTER TABLE"

516− <+> renderAlias tab

517− <+> renderAlterTable alteration

518− <> ";"

519−

520−-- | `alterTableRename` changes the name of a table from the schema.

521−--

522−-- >>> printSQL $ alterTableRename #foo #bar

523−-- ALTER TABLE "foo" RENAME TO "bar";

524−alterTableRename

525− :: (KnownSymbol table0, KnownSymbol table1)

526− => Alias table0 -- ^ table to rename

527− -> Alias table1 -- ^ what to rename it

528− -> Definition schema (Rename table0 table1 schema)

529−alterTableRename table0 table1 = UnsafeDefinition $

530− "ALTER TABLE" <+> renderAlias table0

531− <+> "RENAME TO" <+> renderAlias table1 <> ";"

532−

533−-- | An `AlterTable` describes the alteration to perform on the columns

534−-- of a table.

535−newtype AlterTable

536− (alias :: Symbol)

537− (table :: TableType)

538− (schema :: SchemaType) =

539− UnsafeAlterTable {renderAlterTable :: ByteString}

540− deriving (GHC.Generic,Show,Eq,Ord,NFData)

541−

542−-- | An `addConstraint` adds a table constraint.

543−--

544−-- >>> :{

545−-- let

546−-- definition :: Definition

547−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

548−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

549−-- definition = alterTable #tab (addConstraint #positive (check (#col :* Nil) (#col .> 0)))

550−-- in printSQL definition

551−-- :}

552−-- ALTER TABLE "tab" ADD CONSTRAINT "positive" CHECK (("col" > 0));

553−addConstraint

554− :: ( KnownSymbol alias

555− , Has tab schema ('Table table0)

556− , table0 ~ (constraints :=> columns)

557− , table1 ~ (Create alias constraint constraints :=> columns) )

558− => Alias alias

559− -> TableConstraintExpression schema tab constraint

560− -- ^ constraint to add

561− -> AlterTable tab table1 schema

562−addConstraint alias constraint = UnsafeAlterTable $

563− "ADD" <+> "CONSTRAINT" <+> renderAlias alias

564− <+> renderTableConstraintExpression constraint

565−

566−-- | A `dropConstraint` drops a table constraint.

567−--

568−-- >>> :{

569−-- let

570−-- definition :: Definition

571−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

572−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

573−-- definition = alterTable #tab (dropConstraint #positive)

574−-- in printSQL definition

575−-- :}

576−-- ALTER TABLE "tab" DROP CONSTRAINT "positive";

577−dropConstraint

578− :: ( KnownSymbol constraint

579− , Has tab schema ('Table table0)

580− , table0 ~ (constraints :=> columns)

581− , table1 ~ (Drop constraint constraints :=> columns) )

582− => Alias constraint

583− -- ^ constraint to drop

584− -> AlterTable tab table1 schema

585−dropConstraint constraint = UnsafeAlterTable $

586− "DROP" <+> "CONSTRAINT" <+> renderAlias constraint

587−

588−-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.

589−class AddColumn ty where

590− -- | `addColumn` adds a new column, initially filled with whatever

591− -- default value is given or with @NULL@.

592− --

593− -- >>> :{

594− -- let

595− -- definition :: Definition

596− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

597− -- '["tab" ::: 'Table ('[] :=>

598− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

599− -- , "col2" ::: 'Def :=> 'Null 'PGtext ])]

600− -- definition = alterTable #tab (addColumn #col2 (text & nullable & default_ "foo"))

601− -- in printSQL definition

602− -- :}

603− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL DEFAULT E'foo';

604− --

605− -- >>> :{

606− -- let

607− -- definition :: Definition

608− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

609− -- '["tab" ::: 'Table ('[] :=>

610− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

611− -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]

612− -- definition = alterTable #tab (addColumn #col2 (text & nullable))

613− -- in printSQL definition

614− -- :}

615− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL;

616− addColumn

617− :: ( KnownSymbol column

618− , Has tab schema ('Table table0)

619− , table0 ~ (constraints :=> columns)

620− , table1 ~ (constraints :=> Create column ty columns) )

621− => Alias column -- ^ column to add

622− -> ColumnTypeExpression schema ty -- ^ type of the new column

623− -> AlterTable tab table1 schema

624− addColumn column ty = UnsafeAlterTable $

625− "ADD COLUMN" <+> renderAlias column <+> renderColumnTypeExpression ty

626−instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)

627−instance {-# OVERLAPPABLE #-} AddColumn ('NoDef :=> 'Null ty)

628−

629−-- | A `dropColumn` removes a column. Whatever data was in the column

630−-- disappears. Table constraints involving the column are dropped, too.

631−-- However, if the column is referenced by a foreign key constraint of

632−-- another table, PostgreSQL will not silently drop that constraint.

633−--

634−-- >>> :{

635−-- let

636−-- definition :: Definition

637−-- '["tab" ::: 'Table ('[] :=>

638−-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

639−-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]

640−-- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

641−-- definition = alterTable #tab (dropColumn #col2)

642−-- in printSQL definition

643−-- :}

644−-- ALTER TABLE "tab" DROP COLUMN "col2";

645−dropColumn

646− :: ( KnownSymbol column

647− , Has tab schema ('Table table0)

648− , table0 ~ (constraints :=> columns)

649− , table1 ~ (constraints :=> Drop column columns) )

650− => Alias column -- ^ column to remove

651− -> AlterTable tab table1 schema

652−dropColumn column = UnsafeAlterTable $

653− "DROP COLUMN" <+> renderAlias column

654−

655−-- | A `renameColumn` renames a column.

656−--

657−-- >>> :{

658−-- let

659−-- definition :: Definition

660−-- '["tab" ::: 'Table ('[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4])]

661−-- '["tab" ::: 'Table ('[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4])]

662−-- definition = alterTable #tab (renameColumn #foo #bar)

663−-- in printSQL definition

664−-- :}

665−-- ALTER TABLE "tab" RENAME COLUMN "foo" TO "bar";

666−renameColumn

667− :: ( KnownSymbol column0

668− , KnownSymbol column1

669− , Has tab schema ('Table table0)

670− , table0 ~ (constraints :=> columns)

671− , table1 ~ (constraints :=> Rename column0 column1 columns) )

672− => Alias column0 -- ^ column to rename

673− -> Alias column1 -- ^ what to rename the column

674− -> AlterTable tab table1 schema

675−renameColumn column0 column1 = UnsafeAlterTable $

676− "RENAME COLUMN" <+> renderAlias column0 <+> "TO" <+> renderAlias column1

677−

678−-- | An `alterColumn` alters a single column.

679−alterColumn

680− :: ( KnownSymbol column

681− , Has tab schema ('Table table0)

682− , table0 ~ (constraints :=> columns)

683− , Has column columns ty0

684− , tables1 ~ (constraints :=> Alter column ty1 columns))

685− => Alias column -- ^ column to alter

686− -> AlterColumn schema ty0 ty1 -- ^ alteration to perform

687− -> AlterTable tab table1 schema

688−alterColumn column alteration = UnsafeAlterTable $

689− "ALTER COLUMN" <+> renderAlias column <+> renderAlterColumn alteration

690−

691−-- | An `AlterColumn` describes the alteration to perform on a single column.

692−newtype AlterColumn (schema :: SchemaType) (ty0 :: ColumnType) (ty1 :: ColumnType) =

693− UnsafeAlterColumn {renderAlterColumn :: ByteString}

694− deriving (GHC.Generic,Show,Eq,Ord,NFData)

695−

696−-- | A `setDefault` sets a new default for a column. Note that this doesn't

697−-- affect any existing rows in the table, it just changes the default for

698−-- future insert and update commands.

699−--

700−-- >>> :{

701−-- let

702−-- definition :: Definition

703−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

704−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

705−-- definition = alterTable #tab (alterColumn #col (setDefault 5))

706−-- in printSQL definition

707−-- :}

708−-- ALTER TABLE "tab" ALTER COLUMN "col" SET DEFAULT 5;

709−setDefault

710− :: Expression schema '[] 'Ungrouped '[] ty -- ^ default value to set

711− -> AlterColumn schema (constraint :=> ty) ('Def :=> ty)

712−setDefault expression = UnsafeAlterColumn $

713− "SET DEFAULT" <+> renderExpression expression

714−

715−-- | A `dropDefault` removes any default value for a column.

716−--

717−-- >>> :{

718−-- let

719−-- definition :: Definition

720−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

721−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

722−-- definition = alterTable #tab (alterColumn #col dropDefault)

723−-- in printSQL definition

724−-- :}

725−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP DEFAULT;

726−dropDefault :: AlterColumn schema ('Def :=> ty) ('NoDef :=> ty)

727−dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"

728−

729−-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.

730−-- The constraint will be checked immediately, so the table data must satisfy

731−-- the constraint before it can be added.

732−--

733−-- >>> :{

734−-- let

735−-- definition :: Definition

736−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

737−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

738−-- definition = alterTable #tab (alterColumn #col setNotNull)

739−-- in printSQL definition

740−-- :}

741−-- ALTER TABLE "tab" ALTER COLUMN "col" SET NOT NULL;

742−setNotNull

743− :: AlterColumn schema (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)

744−setNotNull = UnsafeAlterColumn $ "SET NOT NULL"

745−

746−-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.

747−--

748−-- >>> :{

749−-- let

750−-- definition :: Definition

751−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

752−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

753−-- definition = alterTable #tab (alterColumn #col dropNotNull)

754−-- in printSQL definition

755−-- :}

756−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP NOT NULL;

757−dropNotNull

758− :: AlterColumn schema (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)

759−dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"

760−

761−-- | An `alterType` converts a column to a different data type.

762−-- This will succeed only if each existing entry in the column can be

763−-- converted to the new type by an implicit cast.

764−--

765−-- >>> :{

766−-- let

767−-- definition :: Definition

768−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

769−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]

770−-- definition =

771−-- alterTable #tab (alterColumn #col (alterType (numeric & notNullable)))

772−-- in printSQL definition

773−-- :}

774−-- ALTER TABLE "tab" ALTER COLUMN "col" TYPE numeric NOT NULL;

775−alterType :: ColumnTypeExpression schema ty -> AlterColumn schema ty0 ty

776−alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty

777−

778−-- | Create a view.

779−--

780−-- >>> :{

781−-- let

782−-- definition :: Definition

783−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]

784−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

785−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]

786−-- definition =

787−-- createView #bc (select (#b :* #c :* Nil) (from (table #abc)))

788−-- in printSQL definition

789−-- :}

790−-- CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";

791−createView

792− :: KnownSymbol view

793− => Alias view -- ^ the name of the view to add

794− -> Query schema '[] relation

795− -- ^ query

796− -> Definition schema (Create view ('View relation) schema)

797−createView alias query = UnsafeDefinition $

798− "CREATE" <+> "VIEW" <+> renderAlias alias <+> "AS"

799− <+> renderQuery query <> ";"

800−

801−-- | Drop a view.

802−--

803−-- >>> :{

804−-- let

805−-- definition :: Definition

806−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

807−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]

808−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]

809−-- definition = dropView #bc

810−-- in printSQL definition

811−-- :}

812−-- DROP VIEW "bc";

813−dropView

814− :: Has view schema ('View v)

815− => Alias view -- ^ view to remove

816− -> Definition schema (Drop view schema)

817−dropView v = UnsafeDefinition $ "DROP VIEW" <+> renderAlias v <> ";"

818−

819−-- | Enumerated types are created using the `createTypeEnum` command, for example

820−--

821−-- >>> printSQL $ createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy" :* Nil)

822−-- CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');

823−createTypeEnum

824− :: (KnownSymbol enum, SOP.All KnownSymbol labels)

825− => Alias enum

826− -- ^ name of the user defined enumerated type

827− -> NP PGlabel labels

828− -- ^ labels of the enumerated type

829− -> Definition schema (Create enum ('Typedef ('PGenum labels)) schema)

830−createTypeEnum enum labels = UnsafeDefinition $

831− "CREATE" <+> "TYPE" <+> renderAlias enum <+> "AS" <+> "ENUM" <+>

832− parenthesized (commaSeparated (renderLabels labels)) <> ";"

833−

834−-- | Enumerated types can also be generated from a Haskell type, for example

835−--

836−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

837−-- >>> instance SOP.Generic Schwarma

838−-- >>> instance SOP.HasDatatypeInfo Schwarma

839−-- >>> printSQL $ createTypeEnumFrom @Schwarma #schwarma

840−-- CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');

841−createTypeEnumFrom

842− :: forall hask enum schema.

843− ( SOP.Generic hask

844− , SOP.All KnownSymbol (LabelsFrom hask)

845− , KnownSymbol enum

846− )

847− => Alias enum

848− -- ^ name of the user defined enumerated type

849− -> Definition schema (Create enum ('Typedef (EnumFrom hask)) schema)

850−createTypeEnumFrom enum = createTypeEnum enum

851− (SOP.hpure label :: NP PGlabel (LabelsFrom hask))

852−

853−-- | `createTypeComposite` creates a composite type. The composite type is

854−-- specified by a list of attribute names and data types.

855−--

856−-- >>> printSQL $ createTypeComposite #complex (float8 `As` #real :* float8 `As` #imaginary :* Nil)

857−-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

858−createTypeComposite

859− :: (KnownSymbol ty, SOP.SListI fields)

860− => Alias ty

861− -- ^ name of the user defined composite type

862− -> NP (Aliased (TypeExpression schema)) fields

863− -- ^ list of attribute names and data types

864− -> Definition schema (Create ty ('Typedef ('PGcomposite fields)) schema)

865−createTypeComposite ty fields = UnsafeDefinition $

866− "CREATE" <+> "TYPE" <+> renderAlias ty <+> "AS" <+> parenthesized

867− (renderCommaSeparated renderField fields) <> ";"

868− where

869− renderField :: Aliased (TypeExpression schema) x -> ByteString

870− renderField (typ `As` field) =

871− renderAlias field <+> renderTypeExpression typ

872−

873−-- | Composite types can also be generated from a Haskell type, for example

874−--

875−-- >>> data Complex = Complex {real :: Maybe Double, imaginary :: Maybe Double} deriving GHC.Generic

876−-- >>> instance SOP.Generic Complex

877−-- >>> instance SOP.HasDatatypeInfo Complex

878−-- >>> printSQL $ createTypeCompositeFrom @Complex #complex

879−-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

880−createTypeCompositeFrom

881− :: forall hask ty schema.

882− ( ZipAliased (FieldNamesFrom hask) (FieldTypesFrom hask)

883− , SOP.All (PGTyped schema) (FieldTypesFrom hask)

884− , KnownSymbol ty

885− )

886− => Alias ty

887− -- ^ name of the user defined composite type

888− -> Definition schema (Create ty ( 'Typedef (CompositeFrom hask)) schema)

889−createTypeCompositeFrom ty = createTypeComposite ty $ zipAs

890− (SOP.hpure Alias :: NP Alias (FieldNamesFrom hask))

891− (SOP.hcpure (SOP.Proxy :: SOP.Proxy (PGTyped schema)) pgtype

892− :: NP (TypeExpression schema) (FieldTypesFrom hask))

893−

894−-- | Drop a type.

895−--

896−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

897−-- >>> instance SOP.Generic Schwarma

898−-- >>> instance SOP.HasDatatypeInfo Schwarma

899−-- >>> printSQL (dropType #schwarma :: Definition '["schwarma" ::: 'Typedef (EnumFrom Schwarma)] '[])

900−-- DROP TYPE "schwarma";

901−dropType

902− :: Has tydef schema ('Typedef ty)

903− => Alias tydef

904− -- ^ name of the user defined type

905− -> Definition schema (Drop tydef schema)

906−dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderAlias tydef <> ";"

907−

908−-- | `ColumnTypeExpression`s are used in `createTable` commands.

909−newtype ColumnTypeExpression (schema :: SchemaType) (ty :: ColumnType)

910− = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }

911− deriving (GHC.Generic,Show,Eq,Ord,NFData)

912−

913−-- | used in `createTable` commands as a column constraint to note that

914−-- @NULL@ may be present in a column

915−nullable

916− :: TypeExpression schema ty

917− -> ColumnTypeExpression schema ('NoDef :=> 'Null ty)

918−nullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NULL"

919−

920−-- | used in `createTable` commands as a column constraint to ensure

921−-- @NULL@ is not present in a column

922−notNullable

923− :: TypeExpression schema ty

924− -> ColumnTypeExpression schema (def :=> 'NotNull ty)

925−notNullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NOT NULL"

926−

927−-- | used in `createTable` commands as a column constraint to give a default

928−default_

929− :: Expression schema '[] 'Ungrouped '[] ty

930− -> ColumnTypeExpression schema ('NoDef :=> ty)

931− -> ColumnTypeExpression schema ('Def :=> ty)

932−default_ x ty = UnsafeColumnTypeExpression $

933− renderColumnTypeExpression ty <+> "DEFAULT" <+> renderExpression x

934−

935−-- | not a true type, but merely a notational convenience for creating

936−-- unique identifier columns with type `PGint2`

937−serial2, smallserial

938− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint2)

939−serial2 = UnsafeColumnTypeExpression "serial2"

940−smallserial = UnsafeColumnTypeExpression "smallserial"

941−-- | not a true type, but merely a notational convenience for creating

942−-- unique identifier columns with type `PGint4`

943−serial4, serial

944− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint4)

945−serial4 = UnsafeColumnTypeExpression "serial4"

946−serial = UnsafeColumnTypeExpression "serial"

947−-- | not a true type, but merely a notational convenience for creating

948−-- unique identifier columns with type `PGint8`

949−serial8, bigserial

950− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint8)

951−serial8 = UnsafeColumnTypeExpression "serial8"

952−bigserial = UnsafeColumnTypeExpression "bigserial"

74+ renderSQL ddl0 <> "\n" <> renderSQL ddl1

75+

76+-- | A `Manipulation` without input or output can be run as a statement

77+-- along with other `Definition`s, by embedding it using `manipDefinition`.

78+manipDefinition

79+ :: Manipulation '[] schemas '[] '[]

80+ -- ^ no input or output

81+ -> Definition schemas schemas

82+manipDefinition = UnsafeDefinition . (<> ";") . renderSQL

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

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

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

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

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

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

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

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+342−1291

@@ -1,14 +1,13 @@

11{-|

2−Module: Squeal.PostgreSQL.Query

2+Module: Squeal.PostgreSQL.Expression

33Description: Squeal expressions

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

55Maintainer: eitan@morphism.tech

66Stability: experimental

88Squeal expressions are the atoms used to build statements.

99-}

1010

11−{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}

1211{-# LANGUAGE

1312 AllowAmbiguousTypes

1413 , ConstraintKinds

@@ -16,478 +15,368 @@ Squeal expressions are the atoms used to build statements.

1615 , FlexibleContexts

1716 , FlexibleInstances

1817 , FunctionalDependencies

18+ , GADTs

1919 , GeneralizedNewtypeDeriving

2020 , LambdaCase

2121 , MagicHash

2222 , OverloadedStrings

2323 , ScopedTypeVariables

24+ , StandaloneDeriving

2425 , TypeApplications

2526 , TypeFamilies

2627 , TypeInType

2728 , TypeOperators

2829 , UndecidableInstances

30+ , RankNTypes

2931#-}

3032

3133module Squeal.PostgreSQL.Expression

3234 ( -- * Expression

33− Expression (UnsafeExpression, renderExpression)

34− , HasParameter (parameter)

35− , param

36− -- ** Null

37− , null_

38− , notNull

39− , coalesce

40− , fromNull

41− , isNull

42− , isNotNull

43− , matchNull

44− , nullIf

45− -- ** Collections

46− , array

47− , row

48− -- ** Functions

49− , unsafeBinaryOp

50− , unsafeUnaryOp

35+ Expression (..)

36+ , Expr

37+ , type (-->)

38+ , FunctionDB

5139 , unsafeFunction

52− , atan2_

53− , cast

54− , quot_

55− , rem_

56− , trunc

57− , round_

58− , ceiling_

59− , greatest

60− , least

61− -- ** Conditions

62− , Condition

63− , true

64− , false

65− , not_

66− , (.&&)

67− , (.||)

68− , caseWhenThenElse

69− , ifThenElse

70− , (.==)

71− , (./=)

72− , (.>=)

73− , (.<)

74− , (.<=)

75− , (.>)

76− -- ** Time

77− , currentDate

78− , currentTime

79− , currentTimestamp

80− , localTime

81− , localTimestamp

82− -- ** Text

83− , lower

84− , upper

85− , charLength

86− , like

87− -- ** Aggregation

88− , unsafeAggregate, unsafeAggregateDistinct

89− , sum_, sumDistinct

90− , PGAvg (avg, avgDistinct)

91− , bitAnd, bitOr, boolAnd, boolOr

92− , bitAndDistinct, bitOrDistinct, boolAndDistinct, boolOrDistinct

93− , countStar

94− , count, countDistinct

95− , every, everyDistinct

96− , max_, maxDistinct, min_, minDistinct

97− -- * Types

98− , TypeExpression (UnsafeTypeExpression, renderTypeExpression)

99− , PGTyped (pgtype)

100− , bool

101− , int2

102− , smallint

103− , int4

104− , int

105− , integer

106− , int8

107− , bigint

108− , numeric

109− , float4

110− , real

111− , float8

112− , doublePrecision

113− , text

114− , char

115− , character

116− , varchar

117− , characterVarying

118− , bytea

119− , timestamp

120− , timestampWithTimeZone

121− , date

122− , time

123− , timeWithTimeZone

124− , interval

125− , uuid

126− , inet

127− , json

128− , jsonb

129− , vararray

130− , fixarray

40+ , function

41+ , unsafeLeftOp

42+ , leftOp

43+ , unsafeRightOp

44+ , rightOp

45+ , Operator

46+ , OperatorDB

47+ , unsafeBinaryOp

48+ , binaryOp

49+ , FunctionVar

50+ , unsafeFunctionVar

51+ , type (--->)

52+ , FunctionNDB

53+ , unsafeFunctionN

54+ , functionN

55+ , PGSubset (..)

56+ , PGIntersect (..)

13157 -- * Re-export

13258 , (&)

133− , NP ((:*), Nil)

59+ , K (..)

60+ , unK

13461 ) where

13562

13663import Control.Category

13764import Control.DeepSeq

13865import Data.ByteString (ByteString)

13966import Data.Function ((&))

140−import Data.Semigroup

141−import Data.Ratio

67+import Data.Semigroup hiding (All)

14268import Data.String

143−import Generics.SOP hiding (from)

69+import Generics.SOP hiding (All, from)

14470import GHC.OverloadedLabels

14571import GHC.TypeLits

72+import Numeric

14673import Prelude hiding (id, (.))

14774

14875import qualified GHC.Generics as GHC

14976

77+import Squeal.PostgreSQL.Alias

78+import Squeal.PostgreSQL.List

15079import Squeal.PostgreSQL.Render

15180import Squeal.PostgreSQL.Schema

15281

82+-- $setup

83+-- >>> import Squeal.PostgreSQL

84+

15385{-----------------------------------------

15486column expressions

15587-----------------------------------------}

15688

15789{- | `Expression`s are used in a variety of contexts,

158−such as in the target list of the `Squeal.PostgreSQL.Query.select` command,

90+such as in the target `Squeal.PostgreSQL.Query.List` of the

91+`Squeal.PostgreSQL.Query.select` command,

15992as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or

16093`Squeal.PostgreSQL.Manipulation.update`,

161−or in search `Condition`s in a number of commands.

94+or in search `Squeal.PostgreSQL.Logic.Condition`s in a number of commands.

16295

16396The expression syntax allows the calculation of

16497values from primitive expression using arithmetic, logical,

16598and 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`.

166113-}

167114newtype Expression

168− (schema :: SchemaType)

169− (relations :: RelationsType)

170− (grouping :: Grouping)

115+ (outer :: FromType)

116+ (commons :: FromType)

117+ (grp :: Grouping)

118+ (schemas :: SchemasType)

171119 (params :: [NullityType])

120+ (from :: FromType)

172121 (ty :: NullityType)

173122 = UnsafeExpression { renderExpression :: ByteString }

174123 deriving (GHC.Generic,Show,Eq,Ord,NFData)

175−

176−instance RenderSQL (Expression schema relations grouping params ty) where

124+instance RenderSQL (Expression outer commons grp schemas params from ty) where

177125 renderSQL = renderExpression

178126

179−{- | A `HasParameter` constraint is used to indicate a value that is

180−supplied externally to a SQL statement.

181−`Squeal.PostgreSQL.PQ.manipulateParams`,

182−`Squeal.PostgreSQL.PQ.queryParams` and

183−`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values

184−separately from the SQL command string, in which case `param`s are used to

185−refer to the out-of-line data values.

127+-- | An `Expr` is a closed `Expression`.

128+-- It is a F@RankNType@ but don't be scared.

129+-- Think of it as an expression which sees no

130+-- namespaces, so you can't use parameters

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)

186181-}

187−class KnownNat n => HasParameter

188− (n :: Nat)

189− (schema :: SchemaType)

190− (params :: [NullityType])

191− (ty :: NullityType)

192− | n params -> ty where

193− -- | `parameter` takes a `Nat` using type application and a `TypeExpression`.

194− --

195− -- >>> let expr = parameter @1 int4 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)

196− -- >>> printSQL expr

197− -- ($1 :: int4)

198− parameter

199− :: TypeExpression schema (PGTypeOf ty)

200− -> Expression schema relations grouping params ty

201− parameter ty = UnsafeExpression $ parenthesized $

202− "$" <> renderNat (Proxy @n) <+> "::"

203− <+> renderTypeExpression ty

204−instance {-# OVERLAPPING #-} HasParameter 1 schema (ty1:tys) ty1

205−instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) schema params ty)

206− => HasParameter n schema (ty' : params) ty

207−

208−-- | `param` takes a `Nat` using type application and for basic types,

209−-- infers a `TypeExpression`.

210−--

211−-- >>> let expr = param @1 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)

212−-- >>> printSQL expr

213−-- ($1 :: int4)

214−param

215− :: forall n schema params relations grouping ty

216− . (PGTyped schema (PGTypeOf ty), HasParameter n schema params ty)

217− => Expression schema relations grouping params ty -- ^ param

218−param = parameter @n pgtype

219−

220−instance (HasUnique relation relations columns, Has column columns ty)

221− => IsLabel column (Expression schema relations 'Ungrouped params ty) where

222− fromLabel = UnsafeExpression $ renderAlias (Alias @column)

223−instance (HasUnique relation relations columns, Has column columns ty)

224− => IsLabel column

225− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where

226− fromLabel = fromLabel @column `As` Alias @column

227−instance (HasUnique relation relations columns, Has column columns ty)

228− => IsLabel column

229− (NP (Aliased (Expression schema relations 'Ungrouped params)) '[column ::: ty]) where

230− fromLabel = fromLabel @column :* Nil

231−

232−instance (Has relation relations columns, Has column columns ty)

233− => IsQualified relation column (Expression schema relations 'Ungrouped params ty) where

234− relation ! column = UnsafeExpression $

235− renderAlias relation <> "." <> renderAlias column

236−instance (Has relation relations columns, Has column columns ty)

237− => IsQualified relation column

238− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where

239− relation ! column = relation ! column `As` column

240−instance (Has relation relations columns, Has column columns ty)

241− => IsQualified relation column

242− (NP (Aliased (Expression schema relations 'Ungrouped params)) '[column ::: ty]) where

243− relation ! column = relation ! column :* Nil

182+type (--->) xs y

183+ = forall outer commons grp schemas params from

184+ . NP (Expression outer commons grp schemas params from) xs

185+ -- ^ inputs

186+ -> Expression outer commons grp schemas params from y

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

212+unsafeFunctionVar fun xs x = UnsafeExpression $ fun <> parenthesized

213+ (commaSeparated (renderSQL <$> xs) <> ", " <> renderSQL x)

214+

215+instance (HasUnique tab (Join outer from) row, Has col row ty)

216+ => IsLabel col (Expression outer commons 'Ungrouped schemas params from ty) where

217+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)

218+instance (HasUnique tab (Join outer from) row, Has col row ty, tys ~ '[ty])

219+ => IsLabel col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where

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

243+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where

244+ tab ! col = tab ! col :* Nil

244245

245246instance

246− ( HasUnique relation relations columns

247− , Has column columns ty

248− , GroupedBy relation column bys

249− ) => IsLabel column

250− (Expression schema relations ('Grouped bys) params ty) where

251− fromLabel = UnsafeExpression $ renderAlias (Alias @column)

247+ ( HasUnique tab (Join outer from) row

248+ , Has col row ty

249+ , GroupedBy tab col bys

250+ ) => IsLabel col

251+ (Expression outer commons ('Grouped bys) schemas params from ty) where

252+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)

252253instance

253− ( HasUnique relation relations columns

254− , Has column columns ty

255− , GroupedBy relation column bys

256− ) => IsLabel column

257− ( Aliased (Expression schema relations ('Grouped bys) params)

258− (column ::: ty) ) where

259− fromLabel = fromLabel @column `As` Alias @column

254+ ( HasUnique tab (Join outer from) row

255+ , Has col row ty

256+ , GroupedBy tab col bys

257+ , tys ~ '[ty]

258+ ) => IsLabel col

259+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where

260+ fromLabel = fromLabel @col :* Nil

260261instance

261− ( HasUnique relation relations columns

262− , Has column columns ty

263− , GroupedBy relation column bys

264− ) => IsLabel column

265− ( NP (Aliased (Expression schema relations ('Grouped bys) params))

266− '[column ::: ty] ) where

267− fromLabel = fromLabel @column :* Nil

262+ ( HasUnique tab (Join outer from) row

263+ , Has col row ty

264+ , GroupedBy tab col bys

265+ , column ~ (col ::: ty)

266+ ) => IsLabel col

267+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where

268+ fromLabel = fromLabel @col `As` Alias

269+instance

270+ ( HasUnique tab (Join outer from) row

271+ , Has col row ty

272+ , GroupedBy tab col bys

273+ , columns ~ '[col ::: ty]

274+ ) => IsLabel col

275+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where

276+ fromLabel = fromLabel @col :* Nil

268277

269278instance

270− ( Has relation relations columns

271− , Has column columns ty

272− , GroupedBy relation column bys

273− ) => IsQualified relation column

274− (Expression schema relations ('Grouped bys) params ty) where

275− relation ! column = UnsafeExpression $

276− renderAlias relation <> "." <> renderAlias column

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

277286instance

278− ( Has relation relations columns

279− , Has column columns ty

280− , GroupedBy relation column bys

281− ) => IsQualified relation column

282− (Aliased (Expression schema relations ('Grouped bys) params)

283− (column ::: ty)) where

284− relation ! column = relation ! column `As` column

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

285294instance

286− ( Has relation relations columns

287− , Has column columns ty

288− , GroupedBy relation column bys

289− ) => IsQualified relation column

290− ( NP (Aliased (Expression schema relations ('Grouped bys) params))

291− '[column ::: ty]) where

292− relation ! column = relation ! column :* Nil

293−

294−-- | analagous to `Nothing`

295−--

296−-- >>> printSQL null_

297−-- NULL

298−null_ :: Expression schema rels grouping params ('Null ty)

299−null_ = UnsafeExpression "NULL"

300−

301−-- | analagous to `Just`

302−--

303−-- >>> printSQL $ notNull true

304−-- TRUE

305−notNull

306− :: Expression schema rels grouping params ('NotNull ty)

307− -> Expression schema rels grouping params ('Null ty)

308−notNull = UnsafeExpression . renderExpression

309−

310−-- | return the leftmost value which is not NULL

311−--

312−-- >>> printSQL $ coalesce [null_, notNull true] false

313−-- COALESCE(NULL, TRUE, FALSE)

314−coalesce

315− :: [Expression schema relations grouping params ('Null ty)]

316− -- ^ @NULL@s may be present

317− -> Expression schema relations grouping params ('NotNull ty)

318− -- ^ @NULL@ is absent

319− -> Expression schema relations grouping params ('NotNull ty)

320−coalesce nullxs notNullx = UnsafeExpression $

321− "COALESCE" <> parenthesized (commaSeparated

322− ((renderExpression <$> nullxs) <> [renderExpression notNullx]))

323−

324−-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@

325−--

326−-- >>> printSQL $ fromNull true null_

327−-- COALESCE(NULL, TRUE)

328−fromNull

329− :: Expression schema relations grouping params ('NotNull ty)

330− -- ^ what to convert @NULL@ to

331− -> Expression schema relations grouping params ('Null ty)

332− -> Expression schema relations grouping params ('NotNull ty)

333−fromNull notNullx nullx = coalesce [nullx] notNullx

334−

335−-- | >>> printSQL $ null_ & isNull

336−-- NULL IS NULL

337−isNull

338− :: Expression schema relations grouping params ('Null ty)

339− -- ^ possibly @NULL@

340− -> Condition schema relations grouping params

341−isNull x = UnsafeExpression $ renderExpression x <+> "IS NULL"

342−

343−-- | >>> printSQL $ null_ & isNotNull

344−-- NULL IS NOT NULL

345−isNotNull

346− :: Expression schema relations grouping params ('Null ty)

347− -- ^ possibly @NULL@

348− -> Condition schema relations grouping params

349−isNotNull x = UnsafeExpression $ renderExpression x <+> "IS NOT NULL"

350−

351−-- | analagous to `maybe` using @IS NULL@

352−--

353−-- >>> printSQL $ matchNull true not_ null_

354−-- CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END

355−matchNull

356− :: Expression schema relations grouping params (nullty)

357− -- ^ what to convert @NULL@ to

358− -> ( Expression schema relations grouping params ('NotNull ty)

359− -> Expression schema relations grouping params (nullty) )

360− -- ^ function to perform when @NULL@ is absent

361− -> Expression schema relations grouping params ('Null ty)

362− -> Expression schema relations grouping params (nullty)

363−matchNull y f x = ifThenElse (isNull x) y

364− (f (UnsafeExpression (renderExpression x)))

365−

366−{-| right inverse to `fromNull`, if its arguments are equal then

367−`nullIf` gives @NULL@.

368−

369−>>> :set -XTypeApplications -XDataKinds

370−>>> let expr = nullIf false (param @1) :: Expression schema rels grp '[ 'NotNull 'PGbool] ('Null 'PGbool)

371−>>> printSQL expr

372−NULL IF (FALSE, ($1 :: bool))

373−-}

374−nullIf

375− :: Expression schema relations grouping params ('NotNull ty)

376− -- ^ @NULL@ is absent

377− -> Expression schema relations grouping params ('NotNull ty)

378− -- ^ @NULL@ is absent

379− -> Expression schema relations grouping params ('Null ty)

380−nullIf x y = UnsafeExpression $ "NULL IF" <+> parenthesized

381− (renderExpression x <> ", " <> renderExpression y)

382−

383−-- | >>> printSQL $ array [null_, notNull false, notNull true]

384−-- ARRAY[NULL, FALSE, TRUE]

385−array

386− :: [Expression schema relations grouping params ('Null ty)]

387− -- ^ array elements

388− -> Expression schema relations grouping params (nullity ('PGvararray ty))

389−array xs = UnsafeExpression $

390− "ARRAY[" <> commaSeparated (renderExpression <$> xs) <> "]"

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

391310

392311instance (KnownSymbol label, label `In` labels) => IsPGlabel label

393− (Expression schema relations grouping params (nullity ('PGenum labels))) where

394− label = UnsafeExpression $ renderLabel (PGlabel @label)

395−

396−-- | A row constructor is an expression that builds a row value

397−-- (also called a composite value) using values for its member fields.

398−--

399−-- >>> type Complex = PGcomposite '["real" ::: 'PGfloat8, "imaginary" ::: 'PGfloat8]

400−-- >>> let i = row (0 `As` #real :* 1 `As` #imaginary :* Nil) :: Expression '[] '[] 'Ungrouped '[] ('NotNull Complex)

401−-- >>> printSQL i

402−-- ROW(0, 1)

403−row

404− :: SListI (Nulls fields)

405− => NP (Aliased (Expression schema relations grouping params)) (Nulls fields)

406− -- ^ zero or more expressions for the row field values

407− -> Expression schema relations grouping params (nullity ('PGcomposite fields))

408−row exprs = UnsafeExpression $ "ROW" <> parenthesized

409− (renderCommaSeparated (\ (expr `As` _) -> renderExpression expr) exprs)

410−

411−instance Has field fields ty => IsLabel field

412− ( Expression schema relation grouping params (nullity ('PGcomposite fields))

413− -> Expression schema relation grouping params ('Null ty) ) where

414− fromLabel expr = UnsafeExpression $

415− parenthesized (renderExpression expr) <> "." <>

416− fromString (symbolVal (Proxy @field))

417−

418−instance Semigroup

419− (Expression schema relations grouping params (nullity ('PGvararray ty))) where

420− (<>) = unsafeBinaryOp "||"

421−

422−instance Monoid

423− (Expression schema relations grouping params (nullity ('PGvararray ty))) where

424− mempty = array []

425− mappend = (<>)

426−

427−-- | >>> let expr = greatest currentTimestamp [param @1] :: Expression sch rels grp '[ 'NotNull 'PGtimestamptz] ('NotNull 'PGtimestamptz)

428−-- >>> printSQL expr

429−-- GREATEST(CURRENT_TIMESTAMP, ($1 :: timestamp with time zone))

430−greatest

431− :: Expression schema relations grouping params (nullty)

432− -- ^ needs at least 1 argument

433− -> [Expression schema relations grouping params (nullty)]

434− -- ^ or more

435− -> Expression schema relations grouping params (nullty)

436−greatest x xs = UnsafeExpression $ "GREATEST("

437− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

438−

439−-- | >>> printSQL $ least currentTimestamp [null_]

440−-- LEAST(CURRENT_TIMESTAMP, NULL)

441−least

442− :: Expression schema relations grouping params (nullty)

443− -- ^ needs at least 1 argument

444− -> [Expression schema relations grouping params (nullty)]

445− -- ^ or more

446− -> Expression schema relations grouping params (nullty)

447−least x xs = UnsafeExpression $ "LEAST("

448− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

312+ (Expression outer commons grp schemas params from (null ('PGenum labels))) where

313+ label = UnsafeExpression $ renderSQL (PGlabel @label)

449314

450315-- | >>> printSQL $ unsafeBinaryOp "OR" true false

451316-- (TRUE OR FALSE)

452−unsafeBinaryOp

453− :: ByteString

454− -- ^ operator

455− -> Expression schema relations grouping params (ty0)

456− -> Expression schema relations grouping params (ty1)

457− -> Expression schema relations grouping params (ty2)

317+unsafeBinaryOp :: ByteString -> Operator ty0 ty1 ty2

458318unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

459− renderExpression x <+> op <+> renderExpression y

319+ renderSQL x <+> op <+> renderSQL y

320+

321+binaryOp

322+ :: forall op sch schemas schema x y z.

323+ ( Has sch schemas schema

324+ , Has op schema ('Operator ('BinaryOp x y z)) )

325+ => OperatorDB schemas x y z

326+binaryOp = unsafeBinaryOp $ renderSymbol @op

460327

461−-- | >>> printSQL $ unsafeUnaryOp "NOT" true

328+-- | >>> printSQL $ unsafeLeftOp "NOT" true

462329-- (NOT TRUE)

463−unsafeUnaryOp

464− :: ByteString

465− -- ^ operator

466− -> Expression schema relations grouping params (ty0)

467− -> Expression schema relations grouping params (ty1)

468−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $

469− op <+> renderExpression x

330+unsafeLeftOp :: ByteString -> x --> y

331+unsafeLeftOp op x = UnsafeExpression $ parenthesized $ op <+> renderSQL x

332+

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

343+unsafeRightOp op x = UnsafeExpression $ parenthesized $ renderSQL x <+> op

344+

345+rightOp

346+ :: forall op sch schemas schema x y.

347+ ( Has sch schemas schema

348+ , Has op schema ('Operator ('RightOp x y)) )

349+ => FunctionDB schemas x y

350+rightOp = unsafeRightOp $ renderSymbol @op

470351

471352-- | >>> printSQL $ unsafeFunction "f" true

472353-- f(TRUE)

473−unsafeFunction

474− :: ByteString

475− -- ^ function

476− -> Expression schema relations grouping params (xty)

477− -> Expression schema relations grouping params (yty)

354+unsafeFunction :: ByteString -> x --> y

478355unsafeFunction fun x = UnsafeExpression $

479− fun <> parenthesized (renderExpression x)

480−

481−unsafeVariadicFunction

482− :: ByteString

483− -- ^ function

484− -> [Expression schema relations grouping params xty]

485− -> Expression schema relations grouping params (yty)

486−unsafeVariadicFunction fun x = UnsafeExpression $

487− fun <> parenthesized (commaSeparated (map renderExpression x))

488−

489−instance PGNum ty

490− => Num (Expression schema relations grouping params (nullity ty)) where

356+ fun <> parenthesized (renderSQL x)

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+

378+instance ty `In` PGNum

379+ => Num (Expression outer commons grp schemas params from (null ty)) where

491380 (+) = unsafeBinaryOp "+"

492381 (-) = unsafeBinaryOp "-"

493382 (*) = unsafeBinaryOp "*"

@@ -498,19 +387,24 @@ instance PGNum ty

498387 . fromString

499388 . show

500389

501−instance (PGNum ty, PGFloating ty) => Fractional

502− (Expression schema relations grouping params (nullity ty)) where

390+instance (ty `In` PGNum, ty `In` PGFloating) => Fractional

391+ (Expression outer commons grp schemas params from (null ty)) where

503392 (/) = unsafeBinaryOp "/"

504− fromRational x = fromInteger (numerator x) / fromInteger (denominator x)

393+ fromRational

394+ = UnsafeExpression

395+ . fromString

396+ . ($ "")

397+ . showFFloat Nothing

398+ . fromRat @Double

505399

506−instance (PGNum ty, PGFloating ty) => Floating

507− (Expression schema relations grouping params (nullity ty)) where

400+instance (ty `In` PGNum, ty `In` PGFloating) => Floating

401+ (Expression outer commons grp schemas params from (null ty)) where

508402 pi = UnsafeExpression "pi()"

509403 exp = unsafeFunction "exp"

510404 log = unsafeFunction "ln"

511405 sqrt = unsafeFunction "sqrt"

512406 b ** x = UnsafeExpression $

513− "power(" <> renderExpression b <> ", " <> renderExpression x <> ")"

407+ "power(" <> renderSQL b <> ", " <> renderSQL x <> ")"

514408 logBase b y = log y / log b

515409 sin = unsafeFunction "sin"

516410 cos = unsafeFunction "cos"

@@ -525,897 +419,54 @@ instance (PGNum ty, PGFloating ty) => Floating

525419 acosh x = log (x + sqrt (x*x - 1))

526420 atanh x = log ((1 + x) / (1 - x)) / 2

527421

528−-- | >>> :{

529−-- let

530−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

531−-- expression = atan2_ pi 2

532−-- in printSQL expression

533−-- :}

534−-- atan2(pi(), 2)

535−atan2_

536− :: PGFloating float

537− => Expression schema relations grouping params (nullity float)

538− -- ^ numerator

539− -> Expression schema relations grouping params (nullity float)

540− -- ^ denominator

541− -> Expression schema relations grouping params (nullity float)

542−atan2_ y x = UnsafeExpression $

543− "atan2(" <> renderExpression y <> ", " <> renderExpression x <> ")"

544−

545−-- When a `cast` is applied to an `Expression` of a known type, it

546−-- represents a run-time type conversion. The cast will succeed only if a

547−-- suitable type conversion operation has been defined.

548−--

549−-- | >>> printSQL $ true & cast int4

550−-- (TRUE :: int4)

551−cast

552− :: TypeExpression schema ty1

553− -- ^ type to cast as

554− -> Expression schema relations grouping params (nullity ty0)

555− -- ^ value to convert

556− -> Expression schema relations grouping params (nullity ty1)

557−cast ty x = UnsafeExpression $ parenthesized $

558− renderExpression x <+> "::" <+> renderTypeExpression ty

559−

560−-- | integer division, truncates the result

561−--

562−-- >>> :{

563−-- let

564−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

565−-- expression = 5 `quot_` 2

566−-- in printSQL expression

567−-- :}

568−-- (5 / 2)

569−quot_

570− :: PGIntegral int

571− => Expression schema relations grouping params (nullity int)

572− -- ^ numerator

573− -> Expression schema relations grouping params (nullity int)

574− -- ^ denominator

575− -> Expression schema relations grouping params (nullity int)

576−quot_ = unsafeBinaryOp "/"

577−

578−-- | remainder upon integer division

579−--

580−-- >>> :{

581−-- let

582−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

583−-- expression = 5 `rem_` 2

584−-- in printSQL expression

585−-- :}

586−-- (5 % 2)

587−rem_

588− :: PGIntegral int

589− => Expression schema relations grouping params (nullity int)

590− -- ^ numerator

591− -> Expression schema relations grouping params (nullity int)

592− -- ^ denominator

593− -> Expression schema relations grouping params (nullity int)

594−rem_ = unsafeBinaryOp "%"

595−

596−-- | >>> :{

597−-- let

598−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

599−-- expression = trunc pi

600−-- in printSQL expression

601−-- :}

602−-- trunc(pi())

603−trunc

604− :: PGFloating frac

605− => Expression schema relations grouping params (nullity frac)

606− -- ^ fractional number

607− -> Expression schema relations grouping params (nullity frac)

608−trunc = unsafeFunction "trunc"

609−

610−-- | >>> :{

611−-- let

612−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

613−-- expression = round_ pi

614−-- in printSQL expression

615−-- :}

616−-- round(pi())

617−round_

618− :: PGFloating frac

619− => Expression schema relations grouping params (nullity frac)

620− -- ^ fractional number

621− -> Expression schema relations grouping params (nullity frac)

622−round_ = unsafeFunction "round"

623−

624−-- | >>> :{

625−-- let

626−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

627−-- expression = ceiling_ pi

628−-- in printSQL expression

629−-- :}

630−-- ceiling(pi())

631−ceiling_

632− :: PGFloating frac

633− => Expression schema relations grouping params (nullity frac)

634− -- ^ fractional number

635− -> Expression schema relations grouping params (nullity frac)

636−ceiling_ = unsafeFunction "ceiling"

637−

638−-- | A `Condition` is a boolean valued `Expression`. While SQL allows

639−-- conditions to have @NULL@, Squeal instead chooses to disallow @NULL@,

640−-- forcing one to handle the case of @NULL@ explicitly to produce

641−-- a `Condition`.

642−type Condition schema relations grouping params =

643− Expression schema relations grouping params ('NotNull 'PGbool)

644−

645−-- | >>> printSQL true

646−-- TRUE

647−true :: Condition schema relations grouping params

648−true = UnsafeExpression "TRUE"

649−

650−-- | >>> printSQL false

651−-- FALSE

652−false :: Condition schema relations grouping params

653−false = UnsafeExpression "FALSE"

654−

655−-- | >>> printSQL $ not_ true

656−-- (NOT TRUE)

657−not_

658− :: Condition schema relations grouping params

659− -> Condition schema relations grouping params

660−not_ = unsafeUnaryOp "NOT"

661−

662−-- | >>> printSQL $ true .&& false

663−-- (TRUE AND FALSE)

664−(.&&)

665− :: Condition schema relations grouping params

666− -> Condition schema relations grouping params

667− -> Condition schema relations grouping params

668−(.&&) = unsafeBinaryOp "AND"

669−

670−-- | >>> printSQL $ true .|| false

671−-- (TRUE OR FALSE)

672−(.||)

673− :: Condition schema relations grouping params

674− -> Condition schema relations grouping params

675− -> Condition schema relations grouping params

676−(.||) = unsafeBinaryOp "OR"

677−

678−-- | >>> :{

679−-- let

680−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

681−-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3

682−-- in printSQL expression

683−-- :}

684−-- CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END

685−caseWhenThenElse

686− :: [ ( Condition schema relations grouping params

687− , Expression schema relations grouping params (ty)

688− ) ]

689− -- ^ whens and thens

690− -> Expression schema relations grouping params (ty)

691− -- ^ else

692− -> Expression schema relations grouping params (ty)

693−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat

694− [ "CASE"

695− , mconcat

696− [ mconcat

697− [ " WHEN ", renderExpression when_

698− , " THEN ", renderExpression then_

699− ]

700− | (when_,then_) <- whenThens

701− ]

702− , " ELSE ", renderExpression else_

703− , " END"

704− ]

705−

706−-- | >>> :{

707−-- let

708−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

709−-- expression = ifThenElse true 1 0

710−-- in printSQL expression

711−-- :}

712−-- CASE WHEN TRUE THEN 1 ELSE 0 END

713−ifThenElse

714− :: Condition schema relations grouping params

715− -> Expression schema relations grouping params (ty) -- ^ then

716− -> Expression schema relations grouping params (ty) -- ^ else

717− -> Expression schema relations grouping params (ty)

718−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_

719−

720−-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`

721−-- will produce @NULL@s if one of their arguments is @NULL@.

722−--

723−-- >>> printSQL $ notNull true .== null_

724−-- (TRUE = NULL)

725−(.==)

726− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

727− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

728− -> Expression schema relations grouping params (nullity 'PGbool)

729−(.==) = unsafeBinaryOp "="

730−infix 4 .==

731−

732−-- | >>> printSQL $ notNull true ./= null_

733−-- (TRUE <> NULL)

734−(./=)

735− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

736− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

737− -> Expression schema relations grouping params (nullity 'PGbool)

738−(./=) = unsafeBinaryOp "<>"

739−infix 4 ./=

740−

741−-- | >>> printSQL $ notNull true .>= null_

742−-- (TRUE >= NULL)

743−(.>=)

744− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

745− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

746− -> Expression schema relations grouping params (nullity 'PGbool)

747−(.>=) = unsafeBinaryOp ">="

748−infix 4 .>=

749−

750−-- | >>> printSQL $ notNull true .< null_

751−-- (TRUE < NULL)

752−(.<)

753− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

754− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

755− -> Expression schema relations grouping params (nullity 'PGbool)

756−(.<) = unsafeBinaryOp "<"

757−infix 4 .<

758−

759−-- | >>> printSQL $ notNull true .<= null_

760−-- (TRUE <= NULL)

761−(.<=)

762− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

763− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

764− -> Expression schema relations grouping params (nullity 'PGbool)

765−(.<=) = unsafeBinaryOp "<="

766−infix 4 .<=

767−

768−-- | >>> printSQL $ notNull true .> null_

769−-- (TRUE > NULL)

770−(.>)

771− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

772− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

773− -> Expression schema relations grouping params (nullity 'PGbool)

774−(.>) = unsafeBinaryOp ">"

775−infix 4 .>

776−

777−-- | >>> printSQL currentDate

778−-- CURRENT_DATE

779−currentDate

780− :: Expression schema relations grouping params (nullity 'PGdate)

781−currentDate = UnsafeExpression "CURRENT_DATE"

782−

783−-- | >>> printSQL currentTime

784−-- CURRENT_TIME

785−currentTime

786− :: Expression schema relations grouping params (nullity 'PGtimetz)

787−currentTime = UnsafeExpression "CURRENT_TIME"

788−

789−-- | >>> printSQL currentTimestamp

790−-- CURRENT_TIMESTAMP

791−currentTimestamp

792− :: Expression schema relations grouping params (nullity 'PGtimestamptz)

793−currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"

794−

795−-- | >>> printSQL localTime

796−-- LOCALTIME

797−localTime

798− :: Expression schema relations grouping params (nullity 'PGtime)

799−localTime = UnsafeExpression "LOCALTIME"

800−

801−-- | >>> printSQL localTimestamp

802−-- LOCALTIMESTAMP

803−localTimestamp

804− :: Expression schema relations grouping params (nullity 'PGtimestamp)

805−localTimestamp = UnsafeExpression "LOCALTIMESTAMP"

806−

807−{-----------------------------------------

808−text

809−-----------------------------------------}

422+-- | Contained by operators

423+class PGSubset ty where

424+ (@>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

425+ (@>) = unsafeBinaryOp "@>"

426+ (<@) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

427+ (<@) = unsafeBinaryOp "<@"

428+instance PGSubset 'PGjsonb

429+instance PGSubset 'PGtsquery

430+instance PGSubset ('PGvararray ty)

431+instance PGSubset ('PGrange ty)

432+

433+class PGIntersect ty where

434+ (@&&) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

435+ (@&&) = unsafeBinaryOp "&&"

436+instance PGIntersect ('PGvararray ty)

437+instance PGIntersect ('PGrange ty)

810438

811439instance IsString

812− (Expression schema relations grouping params (nullity 'PGtext)) where

440+ (Expression outer commons grp schemas params from (null 'PGtext)) where

813441 fromString str = UnsafeExpression $

814442 "E\'" <> fromString (escape =<< str) <> "\'"

815− where

816− escape = \case

817− '\NUL' -> "\\0"

818− '\'' -> "''"

819− '"' -> "\\\""

820− '\b' -> "\\b"

821− '\n' -> "\\n"

822− '\r' -> "\\r"

823− '\t' -> "\\t"

824− '\\' -> "\\\\"

825− c -> [c]

443+instance IsString

444+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

445+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsvector") $

446+ "E\'" <> fromString (escape =<< str) <> "\'"

447+instance IsString

448+ (Expression outer commons grp schemas params from (null 'PGtsquery)) where

449+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsquery") $

450+ "E\'" <> fromString (escape =<< str) <> "\'"

826451

827452instance Semigroup

828− (Expression schema relations grouping params (nullity 'PGtext)) where

453+ (Expression outer commons grp schemas params from (null ('PGvararray ty))) where

454+ (<>) = unsafeBinaryOp "||"

455+instance Semigroup

456+ (Expression outer commons grp schemas params from (null 'PGjsonb)) where

457+ (<>) = unsafeBinaryOp "||"

458+instance Semigroup

459+ (Expression outer commons grp schemas params from (null 'PGtext)) where

460+ (<>) = unsafeBinaryOp "||"

461+instance Semigroup

462+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

829463 (<>) = unsafeBinaryOp "||"

830464

831465instance Monoid

832− (Expression schema relations grouping params (nullity 'PGtext)) where

466+ (Expression outer commons grp schemas params from (null 'PGtext)) where

467+ mempty = fromString ""

468+ mappend = (<>)

469+instance Monoid

470+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

833471 mempty = fromString ""

834472 mappend = (<>)

835−

836−-- | >>> printSQL $ lower "ARRRGGG"

837−-- lower(E'ARRRGGG')

838−lower

839− :: Expression schema relations grouping params (nullity 'PGtext)

840− -- ^ string to lower case

841− -> Expression schema relations grouping params (nullity 'PGtext)

842−lower = unsafeFunction "lower"

843−

844−-- | >>> printSQL $ upper "eeee"

845−-- upper(E'eeee')

846−upper

847− :: Expression schema relations grouping params (nullity 'PGtext)

848− -- ^ string to upper case

849− -> Expression schema relations grouping params (nullity 'PGtext)

850−upper = unsafeFunction "upper"

851−

852−-- | >>> printSQL $ charLength "four"

853−-- char_length(E'four')

854−charLength

855− :: Expression schema relations grouping params (nullity 'PGtext)

856− -- ^ string to measure

857− -> Expression schema relations grouping params (nullity 'PGint4)

858−charLength = unsafeFunction "char_length"

859−

860−-- | The `like` expression returns true if the @string@ matches

861−-- the supplied @pattern@. If @pattern@ does not contain percent signs

862−-- or underscores, then the pattern only represents the string itself;

863−-- in that case `like` acts like the equals operator. An underscore (_)

864−-- in pattern stands for (matches) any single character; a percent sign (%)

865−-- matches any sequence of zero or more characters.

866−--

867−-- >>> printSQL $ "abc" `like` "a%"

868−-- (E'abc' LIKE E'a%')

869−like

870− :: Expression schema relations grouping params (nullity 'PGtext)

871− -- ^ string

872− -> Expression schema relations grouping params (nullity 'PGtext)

873− -- ^ pattern

874− -> Expression schema relations grouping params (nullity 'PGbool)

875−like = unsafeBinaryOp "LIKE"

876−

877−{-----------------------------------------

878−json and jsonb operators

879−see https://www.postgresql.org/docs/10/static/functions-json.html

880−-----------------------------------------}

881−

882−type IsJSONKey key = key `In` '[ 'PGint2, 'PGint4, 'PGtext ]

883−type IsJSON json = json `In` '[ 'PGjson, 'PGjsonb ]

884−

885−class IsArray arr => IsArrayOf arr ty

886−instance arrTy ~ expectTy => IsArrayOf ('PGvararray arrTy) expectTy

887−instance arrTy ~ expectTy => IsArrayOf ('PGfixarray n arrTy) expectTy

888−

889−-- IsArray will generate nicer error messages when it is all that is required.

890−class IsArray arr

891−instance IsArray ('PGvararray x)

892−instance IsArray ('PGfixarray n x)

893−

894−type IsPGtextArray arr = IsArrayOf arr 'PGtext

895−

896−-- | Get JSON value (object field or array element) at a key.

897−(.->)

898− :: (IsJSON json, IsJSONKey key)

899− => Expression schema relations grouping params (jnull json)

900− -> Expression schema relations grouping params (knull key)

901− -> Expression schema relations grouping params ('Null json)

902−(.->) = unsafeBinaryOp "->"

903−

904−-- | Get JSON value (object field or array element) at a key, as text.

905−(.->>)

906− :: (IsJSON json, IsJSONKey key)

907− => Expression schema relations grouping params (jnull json)

908− -> Expression schema relations grouping params (knull key)

909− -> Expression schema relations grouping params ('Null 'PGtext)

910−(.->>) = unsafeBinaryOp "->>"

911−

912−-- | Get JSON value at a specified path.

913−(.#>)

914− :: (IsJSON json, IsPGtextArray path)

915− => Expression schema relations grouping params (jnull json)

916− -> Expression schema relations grouping params (knull path)

917− -> Expression schema relations grouping params ('Null json)

918−(.#>) = unsafeBinaryOp "#>"

919−

920−-- | Get JSON value at a specified path as text.

921−(.#>>)

922− :: (IsJSON json, IsPGtextArray path)

923− => Expression schema relations grouping params (jnull json)

924− -> Expression schema relations grouping params (knull path)

925− -> Expression schema relations grouping params ('Null 'PGtext)

926−(.#>>) = unsafeBinaryOp "#>"

927−

928−-- Additional jsonb operators

929−

930−-- | Or operator for nulls; if either argument is null, then the result is null.

931−type family Null2 a b where

932− Null2 'Null a = 'Null

933− Null2 a 'Null = 'Null

934− Null2 'NotNull 'NotNull = 'NotNull

935−

936−-- | See 'Null2'

937−type family NullOfN xs where

938− NullOfN ('Null ty:xs) = 'Null

939− NullOfN (x:xs) = NullOfN xs

940− NullOfN '[] = 'NotNull

941−

942−-- | Does the left JSON value contain the right JSON path/value entries at the

943−-- top level?

944−(.@>)

945− :: Expression schema relations grouping params (null0 'PGjsonb)

946− -> Expression schema relations grouping params (null1 'PGjsonb)

947− -> Expression schema relations grouping params (Null2 null0 null1 'PGbool)

948−(.@>) = unsafeBinaryOp "@>"

949−

950−-- | Are the left JSON path/value entries contained at the top level within the

951−-- right JSON value?

952−(.<@)

953− :: Expression schema relations grouping params (null0 'PGjsonb)

954− -> Expression schema relations grouping params (null1 'PGjsonb)

955− -> Expression schema relations grouping params (Null2 null0 null1 'PGbool)

956−(.<@) = unsafeBinaryOp "<@"

957−

958−-- | Does the string exist as a top-level key within the JSON value?

959−(.?)

960− :: Expression schema relations grouping params (null0 'PGjsonb)

961− -> Expression schema relations grouping params (null1 'PGtext)

962− -> Expression schema relations grouping params (Null2 null0 null1 'PGbool)

963−(.?) = unsafeBinaryOp "?"

964−

965−-- | Do any of these array strings exist as top-level keys?

966−(.?|)

967− :: Expression schema relations grouping params (null0 'PGjsonb)

968− -> Expression schema relations grouping params (null1 ('PGvararray 'PGtext))

969− -> Expression schema relations grouping params (Null2 null0 null1 'PGbool)

970−(.?|) = unsafeBinaryOp "?|"

971−

972−-- | Do all of these array strings exist as top-level keys?

973−(.?&)

974− :: Expression schema relations grouping params (null0 'PGjsonb)

975− -> Expression schema relations grouping params (null1 ('PGvararray 'PGtext))

976− -> Expression schema relations grouping params (Null2 null0 null1 'PGbool)

977−(.?&) = unsafeBinaryOp "?&"

978−

979−-- | Concatenate two jsonb values into a new jsonb value

980−(.||.)

981− :: Expression schema relations grouping params (null0 'PGjsonb)

982− -> Expression schema relations grouping params (null1 'PGjsonb)

983− -> Expression schema relations grouping params (Null2 null0 null1 'PGjsonb)

984−(.||.) = unsafeBinaryOp "||"

985−

986−-- | Delete a key or keys from a JSON object, or remove an array element.

987−--

988−-- If the right operand is..

989−--

990−-- @ text @: Delete key/value pair or string element from left operand. Key/value pairs

991−-- are matched based on their key value.

992−--

993−-- @ text[] @: Delete multiple key/value pairs or string elements

994−-- from left operand. Key/value pairs are matched based on their key value.

995−--

996−-- @ integer @: Delete the array element with specified index (Negative integers

997−-- count from the end). Throws an error if top level container is not an array.

998−(.-.)

999− :: (key `In` '[ 'PGtext, 'PGvararray 'PGtext, 'PGint4, 'PGint2 ]) -- hlint error without parens here

1000− => Expression schema relations grouping params (null0 'PGjsonb)

1001− -> Expression schema relations grouping params (null1 key)

1002− -> Expression schema relations grouping params (Null2 null0 null1 'PGjsonb)

1003−(.-.) = unsafeBinaryOp "-"

1004−

1005−-- | Delete the field or element with specified path (for JSON arrays, negative

1006−-- integers count from the end)

1007−(#-.)

1008− :: IsPGtextArray arrayty

1009− => Expression schema relations grouping params (null0 'PGjsonb)

1010− -> Expression schema relations grouping params (null1 arrayty)

1011− -> Expression schema relations grouping params (Null2 null0 null1 'PGjsonb)

1012−(#-.) = unsafeBinaryOp "#-"

1013−

1014−toJson

1015− :: Expression schema relations grouping params (nullity ty)

1016− -> Expression schema relations grouping params (nullity 'PGjson)

1017−toJson = unsafeFunction "to_json"

1018−

1019−toJsonb

1020− :: Expression schema relations grouping params (nullity ty)

1021− -> Expression schema relations grouping params (nullity 'PGjsonb)

1022−toJsonb = unsafeUnaryOp "to_jsonb"

1023−

1024−arrayToJson

1025− :: IsArray arr

1026− => Expression schema relations grouping params (nullity arr)

1027− -> Expression schema relations grouping params (nullity 'PGjson)

1028−arrayToJson = unsafeFunction "array_to_json"

1029−

1030−rowToJson

1031− :: Expression schema relations grouping params (nullity ('PGcomposite ty))

1032− -> Expression schema relations grouping params (nullity 'PGjson)

1033−rowToJson = unsafeFunction "row_to_json"

1034−

1035−-- TODO: jsonBuildArray, jsonbBuildArray, jsonObject, jsonbObject

1036−-- probably something like

1037−-- :: NP (Expression s r g p) xs -> Expression s r g p ('NotNull 'PGjson[b])

1038−

1039−{-----------------------------------------

1040−aggregation

1041−-----------------------------------------}

1042−

1043−-- | escape hatch to define aggregate functions

1044−unsafeAggregate

1045− :: ByteString -- ^ aggregate function

1046− -> Expression schema relations 'Ungrouped params (xty)

1047− -> Expression schema relations ('Grouped bys) params (yty)

1048−unsafeAggregate fun x = UnsafeExpression $ mconcat

1049− [fun, "(", renderExpression x, ")"]

1050−

1051−-- | escape hatch to define aggregate functions over distinct values

1052−unsafeAggregateDistinct

1053− :: ByteString -- ^ aggregate function

1054− -> Expression schema relations 'Ungrouped params (xty)

1055− -> Expression schema relations ('Grouped bys) params (yty)

1056−unsafeAggregateDistinct fun x = UnsafeExpression $ mconcat

1057− [fun, "(DISTINCT ", renderExpression x, ")"]

1058−

1059−-- | >>> :{

1060−-- let

1061−-- expression :: Expression schema '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Grouped bys) params ('Null 'PGnumeric)

1062−-- expression = sum_ #col

1063−-- in printSQL expression

1064−-- :}

1065−-- sum("col")

1066−sum_

1067− :: PGNum ty

1068− => Expression schema relations 'Ungrouped params (nullity ty)

1069− -- ^ what to sum

1070− -> Expression schema relations ('Grouped bys) params (nullity ty)

1071−sum_ = unsafeAggregate "sum"

1072−

1073−-- | >>> :{

1074−-- let

1075−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGnumeric]] ('Grouped bys) params (nullity 'PGnumeric)

1076−-- expression = sumDistinct #col

1077−-- in printSQL expression

1078−-- :}

1079−-- sum(DISTINCT "col")

1080−sumDistinct

1081− :: PGNum ty

1082− => Expression schema relations 'Ungrouped params (nullity ty)

1083− -- ^ what to sum

1084− -> Expression schema relations ('Grouped bys) params (nullity ty)

1085−sumDistinct = unsafeAggregateDistinct "sum"

1086−

1087−-- | A constraint for `PGType`s that you can take averages of and the resulting

1088−-- `PGType`.

1089−class PGAvg ty avg | ty -> avg where

1090− avg, avgDistinct

1091− :: Expression schema relations 'Ungrouped params (nullity ty)

1092− -- ^ what to average

1093− -> Expression schema relations ('Grouped bys) params (nullity avg)

1094− avg = unsafeAggregate "avg"

1095− avgDistinct = unsafeAggregateDistinct "avg"

1096−instance PGAvg 'PGint2 'PGnumeric

1097−instance PGAvg 'PGint4 'PGnumeric

1098−instance PGAvg 'PGint8 'PGnumeric

1099−instance PGAvg 'PGnumeric 'PGnumeric

1100−instance PGAvg 'PGfloat4 'PGfloat8

1101−instance PGAvg 'PGfloat8 'PGfloat8

1102−instance PGAvg 'PGinterval 'PGinterval

1103−

1104−-- | >>> :{

1105−-- let

1106−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1107−-- expression = bitAnd #col

1108−-- in printSQL expression

1109−-- :}

1110−-- bit_and("col")

1111−bitAnd

1112− :: PGIntegral int

1113− => Expression schema relations 'Ungrouped params (nullity int)

1114− -- ^ what to aggregate

1115− -> Expression schema relations ('Grouped bys) params (nullity int)

1116−bitAnd = unsafeAggregate "bit_and"

1117−

1118−-- | >>> :{

1119−-- let

1120−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1121−-- expression = bitOr #col

1122−-- in printSQL expression

1123−-- :}

1124−-- bit_or("col")

1125−bitOr

1126− :: PGIntegral int

1127− => Expression schema relations 'Ungrouped params (nullity int)

1128− -- ^ what to aggregate

1129− -> Expression schema relations ('Grouped bys) params (nullity int)

1130−bitOr = unsafeAggregate "bit_or"

1131−

1132−-- | >>> :{

1133−-- let

1134−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1135−-- expression = bitAndDistinct #col

1136−-- in printSQL expression

1137−-- :}

1138−-- bit_and(DISTINCT "col")

1139−bitAndDistinct

1140− :: PGIntegral int

1141− => Expression schema relations 'Ungrouped params (nullity int)

1142− -- ^ what to aggregate

1143− -> Expression schema relations ('Grouped bys) params (nullity int)

1144−bitAndDistinct = unsafeAggregateDistinct "bit_and"

1145−

1146−-- | >>> :{

1147−-- let

1148−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1149−-- expression = bitOrDistinct #col

1150−-- in printSQL expression

1151−-- :}

1152−-- bit_or(DISTINCT "col")

1153−bitOrDistinct

1154− :: PGIntegral int

1155− => Expression schema relations 'Ungrouped params (nullity int)

1156− -- ^ what to aggregate

1157− -> Expression schema relations ('Grouped bys) params (nullity int)

1158−bitOrDistinct = unsafeAggregateDistinct "bit_or"

1159−

1160−-- | >>> :{

1161−-- let

1162−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1163−-- expression = boolAnd #col

1164−-- in printSQL expression

1165−-- :}

1166−-- bool_and("col")

1167−boolAnd

1168− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1169− -- ^ what to aggregate

1170− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1171−boolAnd = unsafeAggregate "bool_and"

1172−

1173−-- | >>> :{

1174−-- let

1175−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1176−-- expression = boolOr #col

1177−-- in printSQL expression

1178−-- :}

1179−-- bool_or("col")

1180−boolOr

1181− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1182− -- ^ what to aggregate

1183− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1184−boolOr = unsafeAggregate "bool_or"

1185−

1186−-- | >>> :{

1187−-- let

1188−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1189−-- expression = boolAndDistinct #col

1190−-- in printSQL expression

1191−-- :}

1192−-- bool_and(DISTINCT "col")

1193−boolAndDistinct

1194− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1195− -- ^ what to aggregate

1196− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1197−boolAndDistinct = unsafeAggregateDistinct "bool_and"

1198−

1199−-- | >>> :{

1200−-- let

1201−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1202−-- expression = boolOrDistinct #col

1203−-- in printSQL expression

1204−-- :}

1205−-- bool_or(DISTINCT "col")

1206−boolOrDistinct

1207− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1208− -- ^ what to aggregate

1209− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1210−boolOrDistinct = unsafeAggregateDistinct "bool_or"

1211−

1212−-- | A special aggregation that does not require an input

1213−--

1214−-- >>> printSQL countStar

1215−-- count(*)

1216−countStar

1217− :: Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1218−countStar = UnsafeExpression $ "count(*)"

1219−

1220−-- | >>> :{

1221−-- let

1222−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1223−-- expression = count #col

1224−-- in printSQL expression

1225−-- :}

1226−-- count("col")

1227−count

1228− :: Expression schema relations 'Ungrouped params ty

1229− -- ^ what to count

1230− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1231−count = unsafeAggregate "count"

1232−

1233−-- | >>> :{

1234−-- let

1235−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1236−-- expression = countDistinct #col

1237−-- in printSQL expression

1238−-- :}

1239−-- count(DISTINCT "col")

1240−countDistinct

1241− :: Expression schema relations 'Ungrouped params ty

1242− -- ^ what to count

1243− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1244−countDistinct = unsafeAggregateDistinct "count"

1245−

1246−-- | synonym for `boolAnd`

1247−--

1248−-- >>> :{

1249−-- let

1250−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1251−-- expression = every #col

1252−-- in printSQL expression

1253−-- :}

1254−-- every("col")

1255−every

1256− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1257− -- ^ what to aggregate

1258− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1259−every = unsafeAggregate "every"

1260−

1261−-- | synonym for `boolAndDistinct`

1262−--

1263−-- >>> :{

1264−-- let

1265−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1266−-- expression = everyDistinct #col

1267−-- in printSQL expression

1268−-- :}

1269−-- every(DISTINCT "col")

1270−everyDistinct

1271− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1272− -- ^ what to aggregate

1273− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1274−everyDistinct = unsafeAggregateDistinct "every"

1275−

1276−-- | minimum and maximum aggregation

1277−max_, min_, maxDistinct, minDistinct

1278− :: Expression schema relations 'Ungrouped params (nullity ty)

1279− -- ^ what to aggregate

1280− -> Expression schema relations ('Grouped bys) params (nullity ty)

1281−max_ = unsafeAggregate "max"

1282−min_ = unsafeAggregate "min"

1283−maxDistinct = unsafeAggregateDistinct "max"

1284−minDistinct = unsafeAggregateDistinct "min"

1285−

1286−{-----------------------------------------

1287−type expressions

1288−-----------------------------------------}

1289−

1290−-- | `TypeExpression`s are used in `cast`s and `createTable` commands.

1291−newtype TypeExpression (schema :: SchemaType) (ty :: PGType)

1292− = UnsafeTypeExpression { renderTypeExpression :: ByteString }

1293− deriving (GHC.Generic,Show,Eq,Ord,NFData)

1294−

1295−instance (Has alias schema ('Typedef ty))

1296− => IsLabel alias (TypeExpression schema ty) where

1297− fromLabel = UnsafeTypeExpression (renderAlias (fromLabel @alias))

1298−

1299−-- | logical Boolean (true/false)

1300−bool :: TypeExpression schema 'PGbool

1301−bool = UnsafeTypeExpression "bool"

1302−-- | signed two-byte integer

1303−int2, smallint :: TypeExpression schema 'PGint2

1304−int2 = UnsafeTypeExpression "int2"

1305−smallint = UnsafeTypeExpression "smallint"

1306−-- | signed four-byte integer

1307−int4, int, integer :: TypeExpression schema 'PGint4

1308−int4 = UnsafeTypeExpression "int4"

1309−int = UnsafeTypeExpression "int"

1310−integer = UnsafeTypeExpression "integer"

1311−-- | signed eight-byte integer

1312−int8, bigint :: TypeExpression schema 'PGint8

1313−int8 = UnsafeTypeExpression "int8"

1314−bigint = UnsafeTypeExpression "bigint"

1315−-- | arbitrary precision numeric type

1316−numeric :: TypeExpression schema 'PGnumeric

1317−numeric = UnsafeTypeExpression "numeric"

1318−-- | single precision floating-point number (4 bytes)

1319−float4, real :: TypeExpression schema 'PGfloat4

1320−float4 = UnsafeTypeExpression "float4"

1321−real = UnsafeTypeExpression "real"

1322−-- | double precision floating-point number (8 bytes)

1323−float8, doublePrecision :: TypeExpression schema 'PGfloat8

1324−float8 = UnsafeTypeExpression "float8"

1325−doublePrecision = UnsafeTypeExpression "double precision"

1326−-- | variable-length character string

1327−text :: TypeExpression schema 'PGtext

1328−text = UnsafeTypeExpression "text"

1329−-- | fixed-length character string

1330−char, character

1331− :: (KnownNat n, 1 <= n)

1332− => proxy n

1333− -> TypeExpression schema ('PGchar n)

1334−char p = UnsafeTypeExpression $ "char(" <> renderNat p <> ")"

1335−character p = UnsafeTypeExpression $ "character(" <> renderNat p <> ")"

1336−-- | variable-length character string

1337−varchar, characterVarying

1338− :: (KnownNat n, 1 <= n)

1339− => proxy n

1340− -> TypeExpression schema ('PGvarchar n)

1341−varchar p = UnsafeTypeExpression $ "varchar(" <> renderNat p <> ")"

1342−characterVarying p = UnsafeTypeExpression $

1343− "character varying(" <> renderNat p <> ")"

1344−-- | binary data ("byte array")

1345−bytea :: TypeExpression schema 'PGbytea

1346−bytea = UnsafeTypeExpression "bytea"

1347−-- | date and time (no time zone)

1348−timestamp :: TypeExpression schema 'PGtimestamp

1349−timestamp = UnsafeTypeExpression "timestamp"

1350−-- | date and time, including time zone

1351−timestampWithTimeZone :: TypeExpression schema 'PGtimestamptz

1352−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"

1353−-- | calendar date (year, month, day)

1354−date :: TypeExpression schema 'PGdate

1355−date = UnsafeTypeExpression "date"

1356−-- | time of day (no time zone)

1357−time :: TypeExpression schema 'PGtime

1358−time = UnsafeTypeExpression "time"

1359−-- | time of day, including time zone

1360−timeWithTimeZone :: TypeExpression schema 'PGtimetz

1361−timeWithTimeZone = UnsafeTypeExpression "time with time zone"

1362−-- | time span

1363−interval :: TypeExpression schema 'PGinterval

1364−interval = UnsafeTypeExpression "interval"

1365−-- | universally unique identifier

1366−uuid :: TypeExpression schema 'PGuuid

1367−uuid = UnsafeTypeExpression "uuid"

1368−-- | IPv4 or IPv6 host address

1369−inet :: TypeExpression schema 'PGinet

1370−inet = UnsafeTypeExpression "inet"

1371−-- | textual JSON data

1372−json :: TypeExpression schema 'PGjson

1373−json = UnsafeTypeExpression "json"

1374−-- | binary JSON data, decomposed

1375−jsonb :: TypeExpression schema 'PGjsonb

1376−jsonb = UnsafeTypeExpression "jsonb"

1377−-- | variable length array

1378−vararray

1379− :: TypeExpression schema pg

1380− -> TypeExpression schema ('PGvararray pg)

1381−vararray ty = UnsafeTypeExpression $ renderTypeExpression ty <> "[]"

1382−-- | fixed length array

1383−--

1384−-- >>> renderTypeExpression (fixarray (Proxy @2) json)

1385−-- "json[2]"

1386−fixarray

1387− :: KnownNat n

1388− => proxy n

1389− -> TypeExpression schema pg

1390− -> TypeExpression schema ('PGfixarray n pg)

1391−fixarray p ty = UnsafeTypeExpression $

1392− renderTypeExpression ty <> "[" <> renderNat p <> "]"

1393−

1394−-- | `pgtype` is a demoted version of a `PGType`

1395−class PGTyped schema (ty :: PGType) where pgtype :: TypeExpression schema ty

1396−instance PGTyped schema 'PGbool where pgtype = bool

1397−instance PGTyped schema 'PGint2 where pgtype = int2

1398−instance PGTyped schema 'PGint4 where pgtype = int4

1399−instance PGTyped schema 'PGint8 where pgtype = int8

1400−instance PGTyped schema 'PGnumeric where pgtype = numeric

1401−instance PGTyped schema 'PGfloat4 where pgtype = float4

1402−instance PGTyped schema 'PGfloat8 where pgtype = float8

1403−instance PGTyped schema 'PGtext where pgtype = text

1404−instance (KnownNat n, 1 <= n)

1405− => PGTyped schema ('PGchar n) where pgtype = char (Proxy @n)

1406−instance (KnownNat n, 1 <= n)

1407− => PGTyped schema ('PGvarchar n) where pgtype = varchar (Proxy @n)

1408−instance PGTyped schema 'PGbytea where pgtype = bytea

1409−instance PGTyped schema 'PGtimestamp where pgtype = timestamp

1410−instance PGTyped schema 'PGtimestamptz where pgtype = timestampWithTimeZone

1411−instance PGTyped schema 'PGdate where pgtype = date

1412−instance PGTyped schema 'PGtime where pgtype = time

1413−instance PGTyped schema 'PGtimetz where pgtype = timeWithTimeZone

1414−instance PGTyped schema 'PGinterval where pgtype = interval

1415−instance PGTyped schema 'PGuuid where pgtype = uuid

1416−instance PGTyped schema 'PGjson where pgtype = json

1417−instance PGTyped schema 'PGjsonb where pgtype = jsonb

1418−instance PGTyped schema ty => PGTyped schema ('PGvararray ty) where

1419− pgtype = vararray (pgtype @schema @ty)

1420−instance (KnownNat n, PGTyped schema ty) => PGTyped schema ('PGfixarray n ty) where

1421− pgtype = fixarray (Proxy @n) (pgtype @schema @ty)

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Aggregate.hsnew file+462

@@ -0,0 +1,462 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Aggregate

3+Description: Aggregate functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

8+Haskell singly-linked lists are very powerful. This module

9+provides functionality for type-level lists, heterogeneous

10+lists and type aligned lists.

11+-}

12+

13+{-# LANGUAGE

14+ DataKinds

15+ , FlexibleContexts

16+ , GADTs

17+ , LambdaCase

18+ , MultiParamTypeClasses

19+ , OverloadedStrings

20+ , PolyKinds

21+ , QuantifiedConstraints

22+ , RankNTypes

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeFamilies

26+ , TypeOperators

27+ , UndecidableInstances

28+#-}

29+

30+module Squeal.PostgreSQL.List

31+ ( SOP.NP (..)

32+ , (*:)

33+ , Join

34+ , disjoin

35+ , Additional (..)

36+ , Path (..)

37+ , CFunctor (..)

38+ , CFoldable (..)

39+ , CFree (..)

40+ , Elem

41+ , In

42+ , Length

43+ ) where

44+

45+import Control.Category.Free

46+import Data.Function ((&))

47+import Data.Kind

48+import Data.Type.Bool

49+import GHC.TypeLits

50+

51+import Generics.SOP as SOP

52+

53+-- | `Join` is simply promoted `++` and is used in @JOIN@s in

54+-- `Squeal.PostgreSQL.Query.FromClause`s.

55+type family Join xs ys where

56+ Join '[] ys = ys

57+ Join (x ': xs) ys = x ': Join xs ys

58+

59+-- | `disjoin` is a utility function for splitting an `NP` list into pieces.

60+disjoin

61+ :: forall xs ys expr. SListI xs

62+ => NP expr (Join xs ys)

63+ -> (NP expr xs, NP expr ys)

64+disjoin = case sList @xs of

65+ SNil -> \ys -> (Nil, ys)

66+ SCons -> \(x :* xsys) ->

67+ case disjoin xsys of (xs,ys) -> (x :* xs, ys)

68+

69+-- | The `Additional` class is for appending

70+-- type-level list parameterized constructors such as `NP`,

71+-- `Squeal.PostgreSQL.Query.Selection`, and `Squeal.PostgreSQL.Query.FromClause`.

72+class Additional expr where

73+ also :: expr ys -> expr xs -> expr (Join xs ys)

74+instance Additional (NP expr) where

75+ also ys = \case

76+ Nil -> ys

77+ x :* xs -> x :* (xs & also ys)

78+

79+-- | A useful operator for ending an `NP` list of length at least 2 without `Nil`.

80+(*:) :: f x -> f y -> NP f '[x,y]

81+x *: y = x :* y :* Nil

82+infixl 9 *:

83+

84+-- | @Elem@ is a promoted `Data.List.elem`.

85+type family Elem x xs where

86+ Elem x '[] = 'False

87+ Elem x (x ': _) = 'True

88+ Elem x (_ ': x ': _) = 'True

89+ Elem x (_ ': _ ': x ': _) = 'True

90+ Elem x (_ ': _ ': _ ': x ': _) = 'True

91+ Elem x (_ ': _ ': _ ': _ ': x ': _) = 'True

92+ Elem x (_ ': _ ': _ ': _ ': _ ': x ': _) = 'True

93+ Elem x (_ ': xs) = Elem x xs

94+

95+-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.

96+type family In x xs :: Constraint where

97+ In x xs = If (Elem x xs) (() :: Constraint)

98+ (TypeError ('ShowType x ':<>: 'Text " is not in " ':<>: 'ShowType xs))

99+

100+{- | Calculate the `Length` of a type level list

101+

102+>>> :kind! Length '[Char,String,Bool,Double]

103+Length '[Char,String,Bool,Double] :: Nat

104+= 4

105+-}

106+type family Length (xs :: [k]) :: Nat where

107+ Length (_ ': _ ': _ ': _ ': _ : xs) = 5 + Length xs

108+ Length (_ ': _ ': _ ': _ : xs) = 4 + Length xs

109+ Length (_ ': _ ': _ : xs) = 3 + Length xs

110+ Length (_ ': _ : xs) = 2 + Length xs

111+ Length (_ : xs) = 1 + Length xs

112+ Length '[] = 0

squeal-postgresql/src/Squeal/PostgreSQL/Manipulation.hs+411−340

@@ -11,84 +11,139 @@ Squeal data manipulation language.

1111{-# LANGUAGE

1212 DeriveGeneric

1313 , FlexibleContexts

14+ , FlexibleInstances

1415 , GADTs

1516 , GeneralizedNewtypeDeriving

1617 , LambdaCase

18+ , MultiParamTypeClasses

1719 , OverloadedStrings

20+ , PatternSynonyms

21+ , QuantifiedConstraints

1822 , RankNTypes

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeFamilies

1926 , TypeInType

2027 , TypeOperators

28+ , UndecidableInstances

2129#-}

2230

2331module Squeal.PostgreSQL.Manipulation

2432 ( -- * Manipulation

25− Manipulation (UnsafeManipulation, renderManipulation)

33+ Manipulation_

34+ , Manipulation (..)

2635 , queryStatement

27− , ColumnValue (..)

28− , ReturningClause (ReturningStar, Returning)

29− , ConflictClause (OnConflictDoRaise, OnConflictDoNothing, OnConflictDoUpdate)

3036 -- * Insert

31− , insertRows

32− , insertRow

33− , insertRows_

34− , insertRow_

35− , insertQuery

36− , insertQuery_

37− , renderReturningClause

38− , renderConflictClause

37+ , insertInto

38+ , insertInto_

3939 -- * Update

4040 , update

4141 , update_

4242 -- * Delete

4343 , deleteFrom

4444 , deleteFrom_

45− -- * With

46− , with

45+ -- * Clauses

46+ , Optional (..)

47+ , QueryClause (..)

48+ , pattern Values_

49+ , ReturningClause (..)

50+ , pattern Returning_

51+ , ConflictClause (..)

52+ , ConflictTarget (..)

53+ , ConflictAction (..)

54+ , UsingClause (..)

4755 ) where

4856

4957import Control.DeepSeq

5058import Data.ByteString hiding (foldr)

51−import Data.Monoid

59+import Data.Kind (Type)

5260

5361import qualified Generics.SOP as SOP

5462import qualified GHC.Generics as GHC

5563

64+import Squeal.PostgreSQL.Alias

5665import Squeal.PostgreSQL.Expression

66+import Squeal.PostgreSQL.Expression.Logic

67+import Squeal.PostgreSQL.List

68+import Squeal.PostgreSQL.PG

5769import Squeal.PostgreSQL.Render

5870import Squeal.PostgreSQL.Query

5971import Squeal.PostgreSQL.Schema

6072

73+-- $setup

74+-- >>> import Squeal.PostgreSQL

75+-- >>> import Data.Int

76+-- >>> import Data.Time

77+

6178{- |

6279A `Manipulation` is a statement which may modify data in the database,

63−but does not alter the schema. Examples are inserts, updates and deletes.

80+but does not alter its schemas. Examples are inserts, updates and deletes.

6481A `Query` is also considered a `Manipulation` even though it does not modify data.

6582

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+

66125simple insert:

67126

127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]

128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

68129>>> :{

69130let

70− manipulation :: Manipulation

71− '[ "tab" ::: 'Table ('[] :=>

72− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

73− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[] '[]

131+ manipulation :: Manipulation_ (Public Schema) () ()

74132 manipulation =

75− insertRow_ #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)

133+ insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))

76134in printSQL manipulation

77135:}

78136INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)

79137

80138parameterized insert:

81139

140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

82142>>> :{

83143let

84− manipulation :: Manipulation

85− '[ "tab" ::: 'Table ('[] :=>

86− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

87− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

88− '[ 'NotNull 'PGint4, 'NotNull 'PGint4 ] '[]

144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()

89145 manipulation =

90− insertRow_ #tab

91− (Set (param @1) `As` #col1 :* Set (param @2) `As` #col2 :* Nil)

146+ insertInto_ #tab (Values_ (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2))

92147in printSQL manipulation

93148:}

94149INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))

@@ -97,71 +152,48 @@ returning insert:

97152

98153>>> :{

99154let

100− manipulation :: Manipulation

101− '[ "tab" ::: 'Table ('[] :=>

102− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

103− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[]

104− '["fromOnly" ::: 'NotNull 'PGint4]

155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)

105156 manipulation =

106− insertRow #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)

107− OnConflictDoRaise (Returning (#col1 `As` #fromOnly :* Nil))

157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))

158+ OnConflictDoRaise (Returning (#col1 `as` #fromOnly))

108159in printSQL manipulation

109160:}

110−INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT) RETURNING "col1" AS "fromOnly"

161+INSERT INTO "tab" ("col1", "col2") VALUES (2, 3) RETURNING "col1" AS "fromOnly"

111162

112163upsert:

113164

165+>>> type CustomersColumns = '["name" ::: 'NoDef :=> 'NotNull 'PGtext, "email" ::: 'NoDef :=> 'NotNull 'PGtext]

166+>>> type CustomersConstraints = '["uq" ::: 'Unique '["name"]]

167+>>> type CustomersSchema = '["customers" ::: 'Table (CustomersConstraints :=> CustomersColumns)]

114168>>> :{

115169let

116− manipulation :: Manipulation

117− '[ "tab" ::: 'Table ('[] :=>

118− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

119− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

120− '[] '[ "sum" ::: 'NotNull 'PGint4]

170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()

121171 manipulation =

122− insertRows #tab

123− (Set 2 `As` #col1 :* Set 4 `As` #col2 :* Nil)

124− [Set 6 `As` #col1 :* Set 8 `As` #col2 :* Nil]

125− (OnConflictDoUpdate

126− (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

127− [#col1 .== #col2])

128− (Returning $ (#col1 + #col2) `As` #sum :* Nil)

172+ insertInto #customers

173+ (Values_ (Set "John Smith" `as` #name :* Set "john@smith.com" `as` #email))

174+ (OnConflict (OnConstraint #uq)

175+ (DoUpdate (Set (#excluded ! #email <> "; " <> #customers ! #email) `as` #email) []))

176+ (Returning_ Nil)

129177in printSQL manipulation

130178:}

131−INSERT INTO "tab" ("col1", "col2") VALUES (2, 4), (6, 8) ON CONFLICT DO UPDATE SET "col1" = 2 WHERE ("col1" = "col2") RETURNING ("col1" + "col2") AS "sum"

179+INSERT INTO "customers" ("name", "email") VALUES (E'John Smith', E'john@smith.com') ON CONFLICT ON CONSTRAINT "uq" DO UPDATE SET "email" = ("excluded"."email" || (E'; ' || "customers"."email"))

132180

133181query insert:

134182

135183>>> :{

136184let

137− manipulation :: Manipulation

138− '[ "tab" ::: 'Table ('[] :=>

139− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

140− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

141− ])

142− , "other_tab" ::: 'Table ('[] :=>

143− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

144− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

145− ])

146− ] '[] '[]

147− manipulation =

148− insertQuery_ #tab

149− (selectStar (from (table (#other_tab `As` #t))))

185+ manipulation :: Manipulation_ (Public Schema) () ()

186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))

150187in printSQL manipulation

151188:}

152−INSERT INTO "tab" SELECT * FROM "other_tab" AS "t"

189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"

153190

154191update:

155192

156193>>> :{

157194let

158− manipulation :: Manipulation

159− '[ "tab" ::: 'Table ('[] :=>

160− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

161− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[] '[]

162− manipulation =

163− update_ #tab (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

164− (#col1 ./= #col2)

195+ manipulation :: Manipulation_ (Public Schema) () ()

196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)

165197in printSQL manipulation

166198:}

167199UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")

@@ -170,154 +202,178 @@ delete:

170202

171203>>> :{

172204let

173− manipulation :: Manipulation

174− '[ "tab" ::: 'Table ('[] :=>

175− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

176− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[]

177− '[ "col1" ::: 'NotNull 'PGint4

178− , "col2" ::: 'NotNull 'PGint4 ]

179− manipulation = deleteFrom #tab (#col1 .== #col2) ReturningStar

205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)

206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)

180207in printSQL manipulation

181208:}

182209DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *

183−-}

184−newtype Manipulation

185− (schema :: SchemaType)

186− (params :: [NullityType])

187− (columns :: RelationType)

188− = UnsafeManipulation { renderManipulation :: ByteString }

189− deriving (GHC.Generic,Show,Eq,Ord,NFData)

190210

191−instance RenderSQL (Manipulation schema params columns) where

192− renderSQL = renderManipulation

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"

245+-}

246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where

247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)

193248

194249-- | Convert a `Query` into a `Manipulation`.

195250queryStatement

196− :: Query schema params columns

197− -> Manipulation schema params columns

198−queryStatement q = UnsafeManipulation $ renderQuery q

251+ :: Query '[] commons schemas params columns

252+ -- ^ `Query` to embed as a `Manipulation`

253+ -> Manipulation commons schemas params columns

254+queryStatement q = UnsafeManipulation $ renderSQL q

199255

200256{-----------------------------------------

201257INSERT statements

202258-----------------------------------------}

203259

204−-- | Insert multiple rows.

205−--

206−-- When a table is created, it contains no data. The first thing to do

207−-- before a database can be of much use is to insert data. Data is

208−-- conceptually inserted one row at a time. Of course you can also insert

209−-- more than one row, but there is no way to insert less than one row.

210−-- Even if you know only some column values, a complete row must be created.

211−insertRows

212− :: ( SOP.SListI columns

213− , SOP.SListI results

214− , Has tab schema ('Table table)

215− , columns ~ TableToColumns table )

216− => Alias tab -- ^ table to insert into

217− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

218− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

219− -> ConflictClause schema columns params

220− -- ^ what to do in case of constraint conflict

221− -> ReturningClause schema columns params results -- ^ results to return

222− -> Manipulation schema params results

223−insertRows tab rw rws conflict returning = UnsafeManipulation $

224− "INSERT" <+> "INTO" <+> renderAlias tab

225− <+> parenthesized (renderCommaSeparated renderAliasPart rw)

226− <+> "VALUES"

227− <+> commaSeparated

228− ( parenthesized

229− . renderCommaSeparated renderColumnValuePart <$> rw:rws )

230− <> renderConflictClause conflict

231− <> renderReturningClause returning

232− where

233− renderAliasPart, renderColumnValuePart

234− :: Aliased (ColumnValue schema '[] params) ty -> ByteString

235− renderAliasPart (_ `As` name) = renderAlias name

236− renderColumnValuePart (value `As` _) = case value of

237− Default -> "DEFAULT"

238− Set expression -> renderExpression expression

239−

240−-- | Insert a single row.

241−insertRow

242− :: ( SOP.SListI columns

243− , SOP.SListI results

244− , Has tab schema ('Table table)

245− , columns ~ TableToColumns table )

246− => Alias tab -- ^ table to insert into

247− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

248− -> ConflictClause schema columns params

249− -- ^ what to do in case of constraint conflict

250− -> ReturningClause schema columns params results -- ^ results to return

251− -> Manipulation schema params results

252−insertRow tab rw = insertRows tab rw []

253−

254−-- | Insert multiple rows returning `Nil` and raising an error on conflicts.

255−insertRows_

256− :: ( SOP.SListI columns

257− , Has tab schema ('Table table)

258− , columns ~ TableToColumns table )

259− => Alias tab -- ^ table to insert into

260− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

261− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

262− -> Manipulation schema params '[]

263−insertRows_ tab rw rws =

264− insertRows tab rw rws OnConflictDoRaise (Returning Nil)

265−

266−-- | Insert a single row returning `Nil` and raising an error on conflicts.

267−insertRow_

268− :: ( SOP.SListI columns

269− , Has tab schema ('Table table)

270− , columns ~ TableToColumns table )

271− => Alias tab -- ^ table to insert into

272− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

273− -> Manipulation schema params '[]

274−insertRow_ tab rw = insertRow tab rw OnConflictDoRaise (Returning Nil)

275−

276−-- | Insert a `Query`.

277−insertQuery

278− :: ( SOP.SListI columns

279− , SOP.SListI results

260+{- |

261+When a table is created, it contains no data. The first thing to do

262+before a database can be of much use is to insert data. Data is

263+conceptually inserted one row at a time. Of course you can also insert

264+more than one row, but there is no way to insert less than one row.

265+Even if you know only some column values, a complete row must be created.

266+-}

267+insertInto

268+ :: ( Has sch schemas schema

280269 , Has tab schema ('Table table)

281− , columns ~ TableToColumns table )

282− => Alias tab -- ^ table to insert into

283− -> Query schema params (ColumnsToRelation columns)

284− -> ConflictClause schema columns params

285− -- ^ what to do in case of constraint conflict

286− -> ReturningClause schema columns params results -- ^ results to return

287− -> Manipulation schema params results

288−insertQuery tab query conflict returning = UnsafeManipulation $

289− "INSERT" <+> "INTO" <+> renderAlias tab

290− <+> renderQuery query

291− <> renderConflictClause conflict

292− <> renderReturningClause returning

293−

294−-- | Insert a `Query` returning `Nil` and raising an error on conflicts.

295−insertQuery_

296− :: ( SOP.SListI columns

270+ , columns ~ TableToColumns table

271+ , row0 ~ TableToRow table

272+ , SOP.SListI columns

273+ , SOP.SListI row1 )

274+ => QualifiedAlias sch tab

275+ -- ^ table

276+ -> QueryClause commons schemas params columns

277+ -- ^ what to insert

278+ -> ConflictClause tab commons schemas params table

279+ -- ^ what to do in case of conflict

280+ -> ReturningClause commons schemas params '[tab ::: row0] row1

281+ -- ^ what to return

282+ -> Manipulation commons schemas params row1

283+insertInto tab qry conflict ret = UnsafeManipulation $

284+ "INSERT" <+> "INTO" <+> renderSQL tab

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

297292 , Has tab schema ('Table table)

298− , columns ~ TableToColumns table )

299− => Alias tab -- ^ table to insert into

300− -> Query schema params (ColumnsToRelation columns)

301− -> Manipulation schema params '[]

302−insertQuery_ tab query =

303− insertQuery tab query OnConflictDoRaise (Returning Nil)

304−

305−-- | `ColumnValue`s are values to insert or update in a row.

306−-- `Same` updates with the same value.

307−-- `Default` inserts or updates with the @DEFAULT@ value.

308−-- `Set` sets a value to be an `Expression`, which can refer to

309−-- existing value in the row for an update.

310−data ColumnValue

311− (schema :: SchemaType)

312− (columns :: RelationType)

313− (params :: [NullityType])

314− (ty :: ColumnType)

315− where

316− Same :: ColumnValue schema (column ': columns) params ty

317− Default :: ColumnValue schema columns params ('Def :=> ty)

318− Set

319− :: (forall table. Expression schema '[table ::: columns] 'Ungrouped params ty)

320− -> ColumnValue schema columns params (constraint :=> ty)

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)

330+ <+> "VALUES"

331+ <+> commaSeparated

332+ ( parenthesized

333+ . renderCommaSeparated renderValuePart <$> row0 : rows )

334+ Select row0 tab ->

335+ parenthesized (renderCommaSeparatedMaybe renderSQLPartMaybe row0)

336+ <+> "SELECT"

337+ <+> renderCommaSeparatedMaybe renderValuePartMaybe row0

338+ <+> renderSQL tab

339+ Subquery qry -> renderQuery qry

340+ where

341+ renderSQLPartMaybe, renderValuePartMaybe

342+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

343+ -> Maybe ByteString

344+ renderSQLPartMaybe = \case

345+ Default `As` _ -> Nothing

346+ Set _ `As` name -> Just $ renderSQL name

347+ renderValuePartMaybe = \case

348+ Default `As` _ -> Nothing

349+ Set value `As` _ -> Just $ renderExpression value

350+ renderSQLPart, renderValuePart

351+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

352+ -> ByteString

353+ renderSQLPart (_ `As` name) = renderSQL name

354+ renderValuePart (value `As` _) = renderSQL value

355+

356+-- | `Values_` describes a single `NP` list of `Aliased` `Optional` `Expression`s

357+-- whose `ColumnsType` must match the tables'.

358+pattern Values_

359+ :: SOP.SListI columns

360+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

361+ -- ^ row of values

362+ -> QueryClause commons schemas params columns

363+pattern Values_ vals = Values vals []

364+

365+-- | `Optional` is either `Default` or a value, parameterized by an appropriate

366+-- `ColumnConstraint`.

367+data Optional expr ty where

368+ -- | Use the `Default` value for a column.

369+ Default :: Optional expr ('Def :=> ty)

370+ -- | `Set` a value for a column.

371+ Set :: expr ty -> Optional expr (def :=> ty)

372+

373+instance (forall x. RenderSQL (expr x)) => RenderSQL (Optional expr ty) where

374+ renderSQL = \case

375+ Default -> "DEFAULT"

376+ Set expr -> renderSQL expr

321377

322378-- | A `ReturningClause` computes and return value(s) based

323379-- on each row actually inserted, updated or deleted. This is primarily

@@ -325,72 +381,100 @@ data ColumnValue

325381-- serial sequence number. However, any expression using the table's columns

326382-- is allowed. Only rows that were successfully inserted or updated or

327383-- deleted will be returned. For example, if a row was locked

328−-- but not updated because an `OnConflictDoUpdate` condition was not satisfied,

329−-- the row will not be returned. `ReturningStar` will return all columns

330−-- in the row. Use @Returning Nil@ in the common case where no return

384+-- but not updated because an `OnConflict` `DoUpdate` condition was not satisfied,

385+-- the row will not be returned. `Returning` `Star` will return all columns

386+-- in the row. Use `Returning` `Nil` in the common case where no return

331387-- values are desired.

332−data ReturningClause

333− (schema :: SchemaType)

334− (columns :: ColumnsType)

335− (params :: [NullityType])

336− (results :: RelationType)

337− where

338− ReturningStar

339− :: results ~ ColumnsToRelation columns

340− => ReturningClause schema columns params results

341− Returning

342− :: rel ~ ColumnsToRelation columns

343− => NP (Aliased (Expression schema '[table ::: rel] 'Ungrouped params)) results

344− -> ReturningClause schema columns params results

345−

346−-- | Render a `ReturningClause`.

347−renderReturningClause

348− :: SOP.SListI results

349− => ReturningClause schema params columns results

350− -> ByteString

351−renderReturningClause = \case

352− ReturningStar -> " RETURNING *"

353− Returning Nil -> ""

354− Returning results -> " RETURNING"

355− <+> renderCommaSeparated (renderAliasedAs renderExpression) results

388+newtype ReturningClause commons schemas params from row =

389+ Returning (Selection '[] commons 'Ungrouped schemas params from row)

390+

391+instance RenderSQL (ReturningClause commons schemas params from row) where

392+ renderSQL = \case

393+ Returning (List Nil) -> ""

394+ Returning selection -> " RETURNING" <+> renderSQL selection

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)

356403

357404-- | A `ConflictClause` specifies an action to perform upon a constraint

358405-- violation. `OnConflictDoRaise` will raise an error.

359−-- `OnConflictDoNothing` simply avoids inserting a row.

360−-- `OnConflictDoUpdate` updates the existing row that conflicts with the row

406+-- `OnConflict` `DoNothing` simply avoids inserting a row.

407+-- `OnConflict` `DoUpdate` updates the existing row that conflicts with the row

361408-- proposed for insertion.

362−data ConflictClause (schema :: SchemaType) (columns :: ColumnsType) params where

363− OnConflictDoRaise :: ConflictClause schema columns params

364− OnConflictDoNothing :: ConflictClause schema columns params

365− OnConflictDoUpdate

366− :: NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

367− -> [Condition schema '[table ::: ColumnsToRelation columns] 'Ungrouped params]

368− -> ConflictClause schema columns params

409+data ConflictClause tab commons schemas params table where

410+ OnConflictDoRaise :: ConflictClause tab commons schemas params table

411+ OnConflict

412+ :: ConflictTarget constraints

413+ -- ^ conflict target

414+ -> ConflictAction tab commons schemas params columns

415+ -- ^ conflict action

416+ -> ConflictClause tab commons schemas params (constraints :=> columns)

369417

370418-- | Render a `ConflictClause`.

371−renderConflictClause

372− :: SOP.SListI columns

373− => ConflictClause schema columns params

419+instance SOP.SListI (TableToColumns table)

420+ => RenderSQL (ConflictClause tab commons schemas params table) where

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

374463 -> ByteString

375−renderConflictClause = \case

376− OnConflictDoRaise -> ""

377− OnConflictDoNothing -> " ON CONFLICT DO NOTHING"

378− OnConflictDoUpdate updates whs'

379− -> " ON CONFLICT DO UPDATE SET"

380− <+> renderCommaSeparatedMaybe renderUpdate updates

381− <> case whs' of

382− [] -> ""

383− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

384− where

385− renderUpdate

386− :: Aliased (ColumnValue schema columns params) column

387− -> Maybe ByteString

388− renderUpdate = \case

389− Same `As` _ -> Nothing

390− Default `As` column -> Just $

391− renderAlias column <+> "=" <+> "DEFAULT"

392− Set expression `As` column -> Just $

393− renderAlias column <+> "=" <+> renderExpression expression

464+renderUpdate (expr `As` col) = renderSQL col <+> "=" <+> renderSQL expr

465+

466+-- | A `ConflictTarget` specifies the constraint violation that triggers a

467+-- `ConflictAction`.

468+data ConflictTarget constraints where

469+ OnConstraint

470+ :: Has con constraints constraint

471+ => Alias con

472+ -> ConflictTarget constraints

473+

474+-- | Render a `ConflictTarget`

475+instance RenderSQL (ConflictTarget constraints) where

476+ renderSQL (OnConstraint con) =

477+ "ON" <+> "CONSTRAINT" <+> renderSQL con

394478

395479{-----------------------------------------

396480UPDATE statements

@@ -400,108 +484,95 @@ UPDATE statements

400484-- in all rows that satisfy the condition.

401485update

402486 :: ( SOP.SListI columns

403− , SOP.SListI results

487+ , SOP.SListI row1

488+ , Has sch schemas schema

404489 , Has tab schema ('Table table)

405− , columns ~ TableToColumns table )

406− => Alias tab -- ^ table to update

407− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

490+ , row0 ~ TableToRow table

491+ , columns ~ TableToColumns table

492+ , SOP.All (HasIn columns) subcolumns

493+ , AllUnique subcolumns )

494+ => QualifiedAlias sch tab -- ^ table to update

495+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row0]))) subcolumns

408496 -- ^ modified values to replace old values

409− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

497+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row0]

410498 -- ^ condition under which to perform update on a row

411− -> ReturningClause schema columns params results -- ^ results to return

412− -> Manipulation schema params results

499+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

500+ -> Manipulation commons schemas params row1

413501update tab columns wh returning = UnsafeManipulation $

414502 "UPDATE"

415− <+> renderAlias tab

503+ <+> renderSQL tab

416504 <+> "SET"

417− <+> renderCommaSeparatedMaybe renderUpdate columns

418− <+> "WHERE" <+> renderExpression wh

419− <> renderReturningClause returning

420− where

421− renderUpdate

422− :: Aliased (ColumnValue schema columns params) column

423− -> Maybe ByteString

424− renderUpdate = \case

425− Same `As` _ -> Nothing

426− Default `As` column -> Just $

427− renderAlias column <+> "=" <+> "DEFAULT"

428− Set expression `As` column -> Just $

429− renderAlias column <+> "=" <+> renderExpression expression

505+ <+> renderCommaSeparated renderUpdate columns

506+ <+> "WHERE" <+> renderSQL wh

507+ <> renderSQL returning

430508

431509-- | Update a row returning `Nil`.

432510update_

433511 :: ( SOP.SListI columns

512+ , Has sch schemas schema

434513 , Has tab schema ('Table table)

435− , columns ~ TableToColumns table )

436− => Alias tab -- ^ table to update

437− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

514+ , row ~ TableToRow table

515+ , columns ~ TableToColumns table

516+ , SOP.All (HasIn columns) subcolumns

517+ , AllUnique subcolumns )

518+ => QualifiedAlias sch tab -- ^ table to update

519+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row]))) subcolumns

438520 -- ^ modified values to replace old values

439− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

521+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

440522 -- ^ condition under which to perform update on a row

441− -> Manipulation schema params '[]

442−update_ tab columns wh = update tab columns wh (Returning Nil)

523+ -> Manipulation commons schemas params '[]

524+update_ tab columns wh = update tab columns wh (Returning_ Nil)

443525

444526{-----------------------------------------

445527DELETE statements

446528-----------------------------------------}

447529

448−-- | Delete rows of a table.

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+

546+-- | Delete rows from a table.

449547deleteFrom

450− :: ( SOP.SListI results

548+ :: ( SOP.SListI row1

549+ , Has sch schemas schema

451550 , Has tab schema ('Table table)

551+ , row0 ~ TableToRow table

452552 , columns ~ TableToColumns table )

453− => Alias tab -- ^ table to delete from

454− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

553+ => QualifiedAlias sch tab -- ^ table to delete from

554+ -> UsingClause commons schemas params from

555+ -> Condition '[] commons 'Ungrouped schemas params (tab ::: row0 ': from)

455556 -- ^ condition under which to delete a row

456− -> ReturningClause schema columns params results -- ^ results to return

457− -> Manipulation schema params results

458−deleteFrom tab wh returning = UnsafeManipulation $

459− "DELETE FROM" <+> renderAlias tab

460− <+> "WHERE" <+> renderExpression wh

461− <> renderReturningClause returning

557+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

558+ -> Manipulation commons schemas params row1

559+deleteFrom tab using wh returning = UnsafeManipulation $

560+ "DELETE FROM"

561+ <+> renderSQL tab

562+ <> case using of

563+ NoUsing -> ""

564+ Using tables -> " USING" <+> renderSQL tables

565+ <+> "WHERE" <+> renderSQL wh

566+ <> renderSQL returning

462567

463568-- | Delete rows returning `Nil`.

464569deleteFrom_

465− :: ( Has tab schema ('Table table)

570+ :: ( Has sch schemas schema

571+ , Has tab schema ('Table table)

572+ , row ~ TableToRow table

466573 , columns ~ TableToColumns table )

467− => Alias tab -- ^ table to delete from

468− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

574+ => QualifiedAlias sch tab -- ^ table to delete from

575+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

469576 -- ^ condition under which to delete a row

470− -> Manipulation schema params '[]

471−deleteFrom_ tab wh = deleteFrom tab wh (Returning Nil)

472−

473−{-----------------------------------------

474−WITH statements

475−-----------------------------------------}

476−

477−-- | `with` provides a way to write auxiliary statements for use in a larger statement.

478−-- These statements, which are often referred to as Common Table Expressions or CTEs,

479−-- can be thought of as defining temporary tables that exist just for one statement.

480−--

481−-- >>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

482−--

483−-- >>> :{

484−-- let

485−-- manipulation :: Manipulation '["products" ::: 'Table ProductsTable, "products_deleted" ::: 'Table ProductsTable] '[ 'NotNull 'PGdate] '[]

486−-- manipulation = with

487−-- (deleteFrom #products (#date .< param @1) ReturningStar `As` #deleted_rows :* Nil)

488−-- (insertQuery_ #products_deleted (selectStar (from (view (#deleted_rows `As` #t)))))

489−-- in printSQL manipulation

490−-- :}

491−-- WITH "deleted_rows" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "deleted_rows" AS "t"

492−with

493− :: SOP.SListI commons

494− => NP (Aliased (Manipulation schema params)) commons

495− -- ^ common table expressions

496− -> Manipulation (With commons schema) params results

497− -> Manipulation schema params results

498−with commons manipulation = UnsafeManipulation $

499− "WITH" <+> renderCommaSeparated renderCommon commons

500− <+> renderManipulation manipulation

501− where

502− renderCommon

503− :: Aliased (Manipulation schema params) common

504− -> ByteString

505− renderCommon (common `As` alias) =

506− renderAlias alias <+> "AS" <+>

507− parenthesized (renderManipulation common)

577+ -> Manipulation commons schemas params '[]

578+deleteFrom_ tab wh = deleteFrom tab NoUsing wh (Returning_ Nil)

squeal-postgresql/src/Squeal/PostgreSQL/Migration.hs+347−215

@@ -8,8 +8,13 @@ Stability: experimental

88This module defines a `Migration` type to safely

99change the schema of your database over time. Let's see an example!

1010

11+First turn on some extensions.

12+

1113>>> :set -XDataKinds -XOverloadedLabels

1214>>> :set -XOverloadedStrings -XFlexibleContexts -XTypeOperators

15+

16+Next, let's define our `TableType`s.

17+

1318>>> :{

1419type UsersTable =

1520 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

@@ -20,7 +25,7 @@ type UsersTable =

2025

2126>>> :{

2227type EmailsTable =

23− '[ "pk_emails" ::: 'PrimaryKey '["id"]

28+ '[ "pk_emails" ::: 'PrimaryKey '["id"]

2429 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

2530 ] :=>

2631 '[ "id" ::: 'Def :=> 'NotNull 'PGint4

@@ -29,248 +34,293 @@ type EmailsTable =

2934 ]

3035:}

3136

37+Now we can define some `Migration`s to make our tables.

38+

3239>>> :{

3340let

34− makeUsers :: Migration IO '[] '["users" ::: 'Table UsersTable]

41+ makeUsers :: Migration Definition (Public '[]) '["public" ::: '["users" ::: 'Table UsersTable]]

3542 makeUsers = Migration

3643 { name = "make users table"

37− , up = void . define $

38− createTable #users

39− ( serial `As` #id :*

40− (text & notNullable) `As` #name :* Nil )

41− ( primaryKey #id `As` #pk_users :* Nil )

42− , down = void . define $ dropTable #users

44+ , up = createTable #users

45+ ( serial `as` #id :*

46+ notNullable text `as` #name )

47+ ( primaryKey #id `as` #pk_users )

48+ , down = dropTable #users

4349 }

4450:}

4551

4652>>> :{

4753let

48− makeEmails :: Migration IO '["users" ::: 'Table UsersTable]

49− '["users" ::: 'Table UsersTable, "emails" ::: 'Table EmailsTable]

54+ makeEmails :: Migration Definition '["public" ::: '["users" ::: 'Table UsersTable]]

55+ '["public" ::: '["users" ::: 'Table UsersTable, "emails" ::: 'Table EmailsTable]]

5056 makeEmails = Migration

5157 { name = "make emails table"

52− , up = void . define $

53− createTable #emails

54− ( serial `As` #id :*

55− (int & notNullable) `As` #user_id :*

56− (text & nullable) `As` #email :* Nil )

57− ( primaryKey #id `As` #pk_emails :*

58+ , up = createTable #emails

59+ ( serial `as` #id :*

60+ notNullable int `as` #user_id :*

61+ nullable text `as` #email )

62+ ( primaryKey #id `as` #pk_emails :*

5863 foreignKey #user_id #users #id

59− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

60− , down = void . define $ dropTable #emails

64+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

65+ , down = dropTable #emails

6166 }

6267:}

6368

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`.

6570

6671>>> let migrations = makeUsers :>> makeEmails :>> Done

6772

68−>>> :{

69−let

70− numMigrations

71− :: Has "schema_migrations" schema ('Table MigrationsTable)

72− => PQ schema schema IO ()

73− numMigrations = do

74− result <- runQuery (selectStar (from (table (#schema_migrations `As` #m))))

75− num <- ntuples result

76− liftBase $ print num

77−:}

73+Now run the migrations.

7874

75+>>> import Control.Monad.IO.Class

7976>>> :{

8077withConnection "host=localhost port=5432 dbname=exampledb" $

8178 manipulate (UnsafeManipulation "SET client_min_messages TO WARNING;")

8279 -- suppress notices

80+ & pqThen (liftIO (putStrLn "Migrate"))

8381 & pqThen (migrateUp migrations)

84− & pqThen numMigrations

82+ & pqThen (liftIO (putStrLn "Rollback"))

8583 & pqThen (migrateDown migrations)

86− & pqThen numMigrations

8784:}

88−Row 2

89−Row 0

85+Migrate

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.

90122-}

91123

92124{-# LANGUAGE

93125 DataKinds

126+ , DeriveGeneric

127+ , FlexibleContexts

128+ , FlexibleInstances

94129 , GADTs

95130 , LambdaCase

96− , PolyKinds

97131 , OverloadedLabels

132+ , OverloadedStrings

133+ , PolyKinds

134+ , QuantifiedConstraints

135+ , RankNTypes

98136 , TypeApplications

99− , FlexibleContexts

100137 , TypeOperators

101138#-}

102139

103140module Squeal.PostgreSQL.Migration

104141 ( -- * Migration

105142 Migration (..)

106− , migrateUp

107− , migrateDown

108− -- * Aligned lists

109− , AlignedList (..)

110− , single

111− -- * Migration table

143+ , Migratory (..)

144+ , Terminally (..)

145+ , terminally

146+ , pureMigration

112147 , MigrationsTable

113− , createMigrations

114− , insertMigration

115− , deleteMigration

116− , selectMigration

148+ , defaultMain

117149 ) where

118150

119151import Control.Category

120152import Control.Monad

121−import Control.Monad.Base

122−import Control.Monad.Trans.Control

123−import Data.Monoid

124−import Generics.SOP (K(..))

153+import Data.ByteString (ByteString)

154+import Data.Foldable (traverse_)

125155import Data.Function ((&))

156+import Data.List ((\\))

126157import Data.Text (Text)

127−import Prelude hiding (id, (.))

158+import Data.Time (UTCTime)

159+import Prelude hiding ((.), id)

160+import System.Environment

161+import UnliftIO (MonadIO (..))

162+

163+import qualified Data.Text.IO as Text (putStrLn)

164+import qualified Generics.SOP as SOP

165+import qualified GHC.Generics as GHC

128166

129−import Squeal.PostgreSQL

167+import Squeal.PostgreSQL.Alias

168+import Squeal.PostgreSQL.Binary

169+import Squeal.PostgreSQL.Definition

170+import Squeal.PostgreSQL.Definition.Table

171+import Squeal.PostgreSQL.Definition.Table.Constraint

172+import Squeal.PostgreSQL.Expression.Comparison

173+import Squeal.PostgreSQL.Expression.Parameter

174+import Squeal.PostgreSQL.Expression.Time

175+import Squeal.PostgreSQL.Expression.Type

176+import Squeal.PostgreSQL.List

177+import Squeal.PostgreSQL.Manipulation

178+import Squeal.PostgreSQL.PQ

179+import Squeal.PostgreSQL.Query

180+import Squeal.PostgreSQL.Schema

181+import Squeal.PostgreSQL.Transaction

130182

131−-- | A `Migration` should contain an inverse pair of

132−-- `up` and `down` instructions and a unique `name`.

133−data Migration io schema0 schema1 = Migration

183+-- | A `Migration` is a named "isomorphism" over a given category.

184+-- It should contain an inverse pair of `up` and `down`

185+-- instructions and a unique `name`.

186+data Migration p schemas0 schemas1 = Migration

134187 { name :: Text -- ^ The `name` of a `Migration`.

135188 -- Each `name` in a `Migration` should be unique.

136− , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.

137− , down :: PQ schema1 schema0 io () -- ^ The `down` instruction of a `Migration`.

189+ , up :: p schemas0 schemas1 -- ^ The `up` 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

138260 }

139261

140−-- | An `AlignedList` is a type-aligned list or free category.

141−data AlignedList p x0 x1 where

142− Done :: AlignedList p x x

143− (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2

144−infixr 7 :>>

145−instance Category (AlignedList p) where

146− id = Done

147− (.) list = \case

148− Done -> list

149− step :>> steps -> step :>> (steps >>> list)

150−

151−-- | A `single` step.

152−single :: p x0 x1 -> AlignedList p x0 x1

153−single step = step :>> Done

154−

155−-- | Run `Migration`s by creating the `MigrationsTable`

156−-- if it does not exist and then in a transaction, for each each `Migration`

157−-- query to see if the `Migration` is executed. If not, then

158−-- execute the `Migration` and insert its row in the `MigrationsTable`.

159−migrateUp

160− :: MonadBaseControl IO io

161− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run

162− -> PQ

163− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

164− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

165− io ()

166−migrateUp migration =

167− define createMigrations

168− & pqBind okResult

169− & pqThen (transactionallySchema_ (upMigrations migration))

170− where

262+instance Migratory (Terminally PQ IO) where

171263

172− upMigrations

173− :: MonadBaseControl IO io

174− => AlignedList (Migration io) schema0 schema1

175− -> PQ

176− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

177− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

178− io ()

179− upMigrations = \case

180− Done -> return ()

181− step :>> steps -> upMigration step & pqThen (upMigrations steps)

182−

183− upMigration

184− :: MonadBase IO io

185− => Migration io schema0 schema1 -> PQ

186− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

187− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

188− io ()

189− upMigration step =

190− queryExecuted step

191− & pqBind (\ executed ->

192− if executed == 1 -- up step has already been executed

193− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

194− else

195− pqEmbed (up step) -- safely switch schemas

196− & pqThen (manipulateParams insertMigration (Only (name step)))

197− -- insert execution record

198− & pqBind okResult)

199−

200− queryExecuted

201− :: MonadBase IO io

202− => Migration io schema0 schema1 -> PQ

203− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

204− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

205− io Row

206− queryExecuted step = do

207− result <- runQueryParams selectMigration (Only (name step))

208− okResult result

209− ntuples result

210−

211−-- | Rewind `Migration`s by creating the `MigrationsTable`

212−-- if it does not exist and then in a transaction, for each each `Migration`

213−-- query to see if the `Migration` is executed. If it is, then

214−-- rewind the `Migration` and delete its row in the `MigrationsTable`.

215−migrateDown

216− :: MonadBaseControl IO io

217− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind

218− -> PQ

219− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

220− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

221− io ()

222−migrateDown migrations =

223− define createMigrations

224− & pqBind okResult

225− & pqThen (transactionallySchema_ (downMigrations migrations))

226− where

264+ migrateUp migration = unsafePQ . transactionally_ $ do

265+ define createMigrations

266+ upMigrations migration

267+

268+ where

269+

270+ upMigrations

271+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

272+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

273+ upMigrations = \case

274+ Done -> return ()

275+ step :>> steps -> upMigration step >> upMigrations steps

276+

277+ upMigration

278+ :: Migration (Terminally PQ IO) schemas0 schemas1

279+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

280+ upMigration step = do

281+ executed <- queryExecuted step

282+ unless (executed == 1) $ do

283+ unsafePQ . runTerminally $ up step

284+ manipulateParams_ insertMigration (Only (name step))

285+

286+ queryExecuted

287+ :: Migration (Terminally PQ IO) schemas0 schemas1

288+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

289+ queryExecuted step = do

290+ result <- runQueryParams selectMigration (Only (name step))

291+ ntuples result

292+

293+ migrateDown migrations = unsafePQ . transactionally_ $ do

294+ define createMigrations

295+ downMigrations migrations

296+

297+ where

298+

299+ downMigrations

300+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

301+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

302+ downMigrations = \case

303+ Done -> return ()

304+ step :>> steps -> downMigrations steps >> downMigration step

227305

228− downMigrations

229− :: MonadBaseControl IO io

230− => AlignedList (Migration io) schema0 schema1 -> PQ

231− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

232− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

233− io ()

234− downMigrations = \case

235− Done -> return ()

236− step :>> steps -> downMigrations steps & pqThen (downMigration step)

237−

238− downMigration

239− :: MonadBase IO io

240− => Migration io schema0 schema1 -> PQ

241− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

242− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

243− io ()

244− downMigration step =

245− queryExecuted step

246− & pqBind (\ executed ->

247− if executed == 0 -- up step has not been executed

248− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

249− else

250− pqEmbed (down step) -- safely switch schemas

251− & pqThen (manipulateParams deleteMigration (Only (name step)))

252− -- delete execution record

253− & pqBind okResult)

254−

255− queryExecuted

256− :: MonadBase IO io

257− => Migration io schema0 schema1 -> PQ

258− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

259− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

260− io Row

261− queryExecuted step = do

262− result <- runQueryParams selectMigration (Only (name step))

263− okResult result

264− ntuples result

265−

266−okResult :: MonadBase IO io => K Result results -> PQ schema schema io ()

267−okResult result = do

268− status <- resultStatus result

269− when (not (status `elem` [CommandOk, TuplesOk])) $ do

270− errorMessageMaybe <- resultErrorMessage result

271− case errorMessageMaybe of

272− Nothing -> error "migrateDown: unknown error"

273− Just msg -> error ("migrationDown: " <> show msg)

306+ downMigration

307+ :: Migration (Terminally PQ IO) schemas0 schemas1

308+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

309+ downMigration step = do

310+ executed <- queryExecuted step

311+ unless (executed == 0) $ do

312+ unsafePQ . runTerminally $ down step

313+ manipulateParams_ deleteMigration (Only (name step))

314+

315+ queryExecuted

316+ :: Migration (Terminally PQ IO) schemas0 schemas1

317+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

318+ queryExecuted step = do

319+ result <- runQueryParams selectMigration (Only (name step))

320+ ntuples result

321+

322+unsafePQ :: (Functor m) => PQ db0 db1 m x -> PQ db0' db1' m x

323+unsafePQ (PQ pq) = PQ $ fmap (SOP.K . SOP.unK) . pq . SOP.K . SOP.unK

274324

275325-- | The `TableType` for a Squeal migration.

276326type MigrationsTable =

@@ -279,38 +329,120 @@ type MigrationsTable =

279329 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

280330 ]

281331

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+

282343-- | Creates a `MigrationsTable` if it does not already exist.

283−createMigrations

284− :: Has "schema_migrations" schema ('Table MigrationsTable)

285− => Definition schema schema

344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas

286345createMigrations =

287346 createTableIfNotExists #schema_migrations

288− ( (text & notNullable) `As` #name :*

347+ ( (text & notNullable) `as` #name :*

289348 (timestampWithTimeZone & notNullable & default_ currentTimestamp)

290− `As` #executed_at :* Nil )

291− ( unique (#name :* Nil) `As` #migrations_unique_name :* Nil )

292−

293−-- | Inserts a `Migration` into the `MigrationsTable`

294−insertMigration

295− :: Has "schema_migrations" schema ('Table MigrationsTable)

296− => Manipulation schema '[ 'NotNull 'PGtext] '[]

297−insertMigration = insertRow_ #schema_migrations

298− ( Set (param @1) `As` #name :*

299− Default `As` #executed_at :* Nil )

300−

301−-- | Deletes a `Migration` from the `MigrationsTable`

302−deleteMigration

303− :: Has "schema_migrations" schema ('Table MigrationsTable)

304− => Manipulation schema '[ 'NotNull 'PGtext ] '[]

349+ `as` #executed_at )

350+ ( unique #name `as` #migrations_unique_name )

351+

352+-- | Inserts a `Migration` into the `MigrationsTable`, returning

353+-- the time at which it was inserted.

354+insertMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

355+insertMigration = insertInto_ #schema_migrations

356+ (Values_ (Set (param @1) `as` #name :* Default `as` #executed_at))

357+

358+-- | Deletes a `Migration` from the `MigrationsTable`, returning

359+-- the time at which it was inserted.

360+deleteMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

305361deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

306362

307363-- | Selects a `Migration` from the `MigrationsTable`, returning

308−-- the time at which it was executed.

364+-- the time at which it was inserted.

309365selectMigration

310− :: Has "schema_migrations" schema ('Table MigrationsTable)

311− => Query schema '[ 'NotNull 'PGtext ]

312− '[ "executed_at" ::: 'NotNull 'PGtimestamptz ]

313−selectMigration = select

314− (#executed_at `As` #executed_at :* Nil)

315− ( from (table (#schema_migrations `As` #m))

316− & where_ (#name .== param @1))

366+ :: Query_ MigrationsSchemas (Only Text) (Only UTCTime)

367+selectMigration = select_ (#executed_at `as` #fromOnly)

368+ $ from (table (#schema_migrations))

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

8+`Squeal.PostgreSQL.PG` provides type families for turning Haskell

9+`Type`s into corresponding Postgres types.

10+-}

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DeriveAnyClass

14+ , DeriveFoldable

15+ , DeriveFunctor

16+ , DeriveGeneric

17+ , DeriveTraversable

18+ , DerivingStrategies

19+ , DefaultSignatures

20+ , FlexibleContexts

21+ , FlexibleInstances

22+ , FunctionalDependencies

23+ , GADTs

24+ , LambdaCase

25+ , MultiParamTypeClasses

26+ , OverloadedStrings

27+ , ScopedTypeVariables

28+ , TypeApplications

29+ , TypeFamilies

30+ , TypeInType

31+ , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

34+#-}

35+

36+module Squeal.PostgreSQL.PG

37+ ( -- * PG embeddings

38+ PG

39+ , NullPG

40+ , TuplePG

41+ , RowPG

42+ -- * Storage newtypes

43+ , Money (..)

44+ , Json (..)

45+ , Jsonb (..)

46+ , Composite (..)

47+ , Enumerated (..)

48+ , VarArray (..)

49+ , FixArray (..)

50+ , LibPQ.Oid (..)

51+ -- * Type families

52+ , LabelsPG

53+ , DimPG

54+ , FixPG

55+ , TupleOf

56+ , TupleCodeOf

57+ , RowOf

58+ , ConstructorsOf

59+ , ConstructorNameOf

60+ , ConstructorNamesOf

61+ ) where

62+

63+import Data.Aeson (Value)

64+import Data.Kind (Type)

65+import Data.Int (Int16, Int32, Int64)

66+import Data.Scientific (Scientific)

67+import Data.Time (Day, DiffTime, LocalTime, TimeOfDay, TimeZone, UTCTime)

68+import Data.Vector (Vector)

69+import Data.UUID.Types (UUID)

70+import GHC.TypeLits

71+import Network.IP.Addr (NetAddr, IP)

72+

73+import qualified Data.ByteString.Lazy as Lazy (ByteString)

74+import qualified Data.ByteString as Strict (ByteString)

75+import qualified Data.Text.Lazy as Lazy (Text)

76+import qualified Data.Text as Strict (Text)

77+import qualified Database.PostgreSQL.LibPQ as LibPQ

78+import qualified GHC.Generics as GHC

79+import qualified Generics.SOP as SOP

80+import qualified Generics.SOP.Record as SOP

81+import qualified Generics.SOP.Type.Metadata as Type

82+

83+import Squeal.PostgreSQL.Alias

84+import Squeal.PostgreSQL.Schema

85+

86+-- $setup

87+-- >>> import Squeal.PostgreSQL

88+-- >>> import Data.Text (Text)

89+

90+{- | The `PG` type family embeds a subset of Haskell types

91+as Postgres types. As an open type family, `PG` is extensible.

92+

93+>>> :kind! PG LocalTime

94+PG LocalTime :: PGType

95+= 'PGtimestamp

96+

97+>>> newtype MyDouble = My Double

98+>>> :set -XTypeFamilies

99+>>> type instance PG MyDouble = 'PGfloat8

100+-}

101+type family PG (hask :: Type) :: PGType

102+-- | `PGbool`

103+type instance PG Bool = 'PGbool

104+-- | `PGint2`

105+type instance PG Int16 = 'PGint2

106+-- | `PGint4`

107+type instance PG Int32 = 'PGint4

108+-- | `PGint8`

109+type instance PG Int64 = 'PGint8

110+-- | `PGint2`

111+type instance PG LibPQ.Oid = 'PGoid

112+-- | `PGnumeric`

113+type instance PG Scientific = 'PGnumeric

114+-- | `PGfloat4`

115+type instance PG Float = 'PGfloat4

116+-- | `PGfloat8`

117+type instance PG Double = 'PGfloat8

118+-- | `PGchar` @1@

119+type instance PG Char = 'PGchar 1

120+-- | `PGtext`

121+type instance PG Strict.Text = 'PGtext

122+-- | `PGtext`

123+type instance PG Lazy.Text = 'PGtext

124+-- | `PGtext`

125+type instance PG String = 'PGtext

126+-- | `PGbytea`

127+type instance PG Strict.ByteString = 'PGbytea

128+-- | `PGbytea`

129+type instance PG Lazy.ByteString = 'PGbytea

130+-- | `PGtimestamp`

131+type instance PG LocalTime = 'PGtimestamp

132+-- | `PGtimestamptz`

133+type instance PG UTCTime = 'PGtimestamptz

134+-- | `PGdate`

135+type instance PG Day = 'PGdate

136+-- | `PGtime`

137+type instance PG TimeOfDay = 'PGtime

138+-- | `PGtimetz`

139+type instance PG (TimeOfDay, TimeZone) = 'PGtimetz

140+-- | `PGinterval`

141+type instance PG DiffTime = 'PGinterval

142+-- | `PGuuid`

143+type instance PG UUID = 'PGuuid

144+-- | `PGinet`

145+type instance PG (NetAddr IP) = 'PGinet

146+-- | `PGjson`

147+type instance PG Value = 'PGjson

148+

149+{-| The `LabelsPG` type family calculates the constructors of a

150+Haskell enum type.

151+

152+>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

153+>>> instance SOP.Generic Schwarma

154+>>> instance SOP.HasDatatypeInfo Schwarma

155+>>> :kind! LabelsPG Schwarma

156+LabelsPG Schwarma :: [Type.ConstructorName]

157+= '["Beef", "Lamb", "Chicken"]

158+-}

159+type family LabelsPG (hask :: Type) :: [Type.ConstructorName] where

160+ LabelsPG hask =

161+ ConstructorNamesOf (ConstructorsOf (SOP.DatatypeInfoOf hask))

162+

163+{- |

164+`RowPG` turns a Haskell `Type` into a `RowType`.

165+

166+`RowPG` may be applied to normal Haskell record types provided they

167+have `SOP.Generic` and `SOP.HasDatatypeInfo` instances;

168+

169+>>> data Person = Person { name :: Strict.Text, age :: Int32 } deriving GHC.Generic

170+>>> instance SOP.Generic Person

171+>>> instance SOP.HasDatatypeInfo Person

172+>>> :kind! RowPG Person

173+RowPG Person :: [(Symbol, NullityType)]

174+= '["name" ::: 'NotNull 'PGtext, "age" ::: 'NotNull 'PGint4]

175+-}

176+type family RowPG (hask :: Type) :: RowType where

177+ RowPG hask = RowOf (SOP.RecordCodeOf hask)

178+

179+-- | `RowOf` applies `NullPG` to the fields of a list.

180+type family RowOf (record :: [(Symbol, Type)]) :: RowType where

181+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': col4 ::: ty4 ': record) =

182+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': col4 ::: NullPG ty4 ': RowOf record

183+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': record) =

184+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': RowOf record

185+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': record) =

186+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': RowOf record

187+ RowOf (col ::: ty ': col1 ::: ty1 ': record) =

188+ col ::: NullPG ty ': col1::: NullPG ty1 ': RowOf record

189+ RowOf (col ::: ty ': record) = col ::: NullPG ty ': RowOf record

190+ RowOf '[] = '[]

191+

192+{- | `NullPG` turns a Haskell type into a `NullityType`.

193+

194+>>> :kind! NullPG Double

195+NullPG Double :: NullityType

196+= 'NotNull 'PGfloat8

197+>>> :kind! NullPG (Maybe Double)

198+NullPG (Maybe Double) :: NullityType

199+= 'Null 'PGfloat8

200+-}

201+type family NullPG (hask :: Type) :: NullityType where

202+ NullPG (Maybe hask) = 'Null (PG hask)

203+ NullPG hask = 'NotNull (PG hask)

204+

205+{- | `TuplePG` turns a Haskell tuple type (including record types) into

206+the corresponding list of `NullityType`s.

207+

208+>>> :kind! TuplePG (Double, Maybe Char)

209+TuplePG (Double, Maybe Char) :: [NullityType]

210+= '[ 'NotNull 'PGfloat8, 'Null ('PGchar 1)]

211+-}

212+type family TuplePG (hask :: Type) :: [NullityType] where

213+ TuplePG hask = TupleOf (TupleCodeOf hask (SOP.Code hask))

214+

215+-- | `TupleOf` turns a list of Haskell `Type`s into a list of `NullityType`s.

216+type family TupleOf (tuple :: [Type]) :: [NullityType] where

217+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': hask5 ': tuple) =

218+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': NullPG hask5 ': TupleOf tuple

219+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': tuple) =

220+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': TupleOf tuple

221+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': tuple) =

222+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': TupleOf tuple

223+ TupleOf (hask ': hask1 ': hask2 ': tuple) =

224+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': TupleOf tuple

225+ TupleOf (hask ': hask1 ': tuple) = NullPG hask ': NullPG hask1 ': TupleOf tuple

226+ TupleOf (hask ': tuple) = NullPG hask ': TupleOf tuple

227+ TupleOf '[] = '[]

228+

229+-- | `TupleCodeOf` takes the `SOP.Code` of a haskell `Type`

230+-- and if it's a simple product returns it, otherwise giving a `TypeError`.

231+type family TupleCodeOf (hask :: Type) (code :: [[Type]]) :: [Type] where

232+ TupleCodeOf hask '[tuple] = tuple

233+ TupleCodeOf hask '[] =

234+ TypeError

235+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

236+ ':$$: 'Text "It is a void type with no constructors."

237+ )

238+ TupleCodeOf hask (_ ': _ ': _) =

239+ TypeError

240+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

241+ ':$$: 'Text "It is a sum type with more than one constructor."

242+ )

243+

244+-- | Calculates constructors of a datatype.

245+type family ConstructorsOf (datatype :: Type.DatatypeInfo)

246+ :: [Type.ConstructorInfo] where

247+ ConstructorsOf ('Type.ADT _module _datatype constructors) =

248+ constructors

249+ ConstructorsOf ('Type.Newtype _module _datatype constructor) =

250+ '[constructor]

251+

252+-- | Calculates the name of a nullary constructor, otherwise

253+-- generates a type error.

254+type family ConstructorNameOf (constructor :: Type.ConstructorInfo)

255+ :: Type.ConstructorName where

256+ ConstructorNameOf ('Type.Constructor name) = name

257+ ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

258+ ('Text "ConstructorNameOf error: non-nullary constructor "

259+ ':<>: 'Text name)

260+ ConstructorNameOf ('Type.Record name _fields) = TypeError

261+ ('Text "ConstructorNameOf error: non-nullary constructor "

262+ ':<>: 'Text name)

263+

264+-- | Calculate the names of nullary constructors.

265+type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

266+ :: [Type.ConstructorName] where

267+ ConstructorNamesOf '[] = '[]

268+ ConstructorNamesOf (constructor ': constructors) =

269+ ConstructorNameOf constructor ': ConstructorNamesOf constructors

270+

271+-- | `DimPG` turns Haskell nested homogeneous tuples into a list of lengths.

272+type family DimPG (hask :: Type) :: [Nat] where

273+ DimPG (x,x) = 2 ': DimPG x

274+ DimPG (x,x,x) = 3 ': DimPG x

275+ DimPG (x,x,x,x) = 4 ': DimPG x

276+ DimPG (x,x,x,x,x) = 5 ': DimPG x

277+ DimPG (x,x,x,x,x,x) = 6 ': DimPG x

278+ DimPG (x,x,x,x,x,x,x) = 7 ': DimPG x

279+ DimPG (x,x,x,x,x,x,x,x) = 8 ': DimPG x

280+ DimPG (x,x,x,x,x,x,x,x,x) = 9 ': DimPG x

281+ DimPG (x,x,x,x,x,x,x,x,x,x) = 10 ': DimPG x

282+ DimPG x = '[]

283+

284+-- | `FixPG` extracts `NullPG` of the base type of nested homogeneous tuples.

285+type family FixPG (hask :: Type) :: NullityType where

286+ FixPG (x,x) = FixPG x

287+ FixPG (x,x,x) = FixPG x

288+ FixPG (x,x,x,x) = FixPG x

289+ FixPG (x,x,x,x,x) = FixPG x

290+ FixPG (x,x,x,x,x,x) = FixPG x

291+ FixPG (x,x,x,x,x,x,x) = FixPG x

292+ FixPG (x,x,x,x,x,x,x,x) = FixPG x

293+ FixPG (x,x,x,x,x,x,x,x,x) = FixPG x

294+ FixPG (x,x,x,x,x,x,x,x,x,x) = FixPG x

295+ FixPG (x,x,x,x,x,x,x,x,x,x,x) = FixPG x

296+ FixPG x = NullPG x

297+

298+{- | The `Money` newtype stores a monetary value in terms

299+of the number of cents, i.e. @$2,000.20@ would be expressed as

300+@Money { cents = 200020 }@.

301+

302+>>> import Control.Monad (void)

303+>>> import Control.Monad.IO.Class (liftIO)

304+>>> import Squeal.PostgreSQL

305+>>> :{

306+let

307+ roundTrip :: Query_ (Public '[]) (Only Money) (Only Money)

308+ roundTrip = values_ $ parameter @1 money `as` #fromOnly

309+:}

310+

311+>>> let input = Only (Money 20020)

312+

313+>>> :{

314+withConnection "host=localhost port=5432 dbname=exampledb" $ do

315+ result <- runQueryParams roundTrip input

316+ Just output <- firstRow result

317+ liftIO . print $ input == output

318+:}

319+True

320+-}

321+newtype Money = Money { cents :: Int64 }

322+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

323+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

324+-- | `PGmoney`

325+type instance PG Money = 'PGmoney

326+

327+{- | The `Json` newtype is an indication that the Haskell

328+type it's applied to should be stored as a `PGjson`.

329+-}

330+newtype Json hask = Json {getJson :: hask}

331+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

332+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

333+-- | `PGjson`

334+type instance PG (Json hask) = 'PGjson

335+

336+{- | The `Jsonb` newtype is an indication that the Haskell

337+type it's applied to should be stored as a `PGjsonb`.

338+-}

339+newtype Jsonb hask = Jsonb {getJsonb :: hask}

340+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

341+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

342+-- | `PGjsonb`

343+type instance PG (Jsonb hask) = 'PGjsonb

344+

345+{- | The `Composite` newtype is an indication that the Haskell

346+type it's applied to should be stored as a `PGcomposite`.

347+-}

348+newtype Composite record = Composite {getComposite :: record}

349+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

350+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

351+-- | `PGcomposite` @(@`RowPG` @hask)@

352+type instance PG (Composite hask) = 'PGcomposite (RowPG hask)

353+

354+{- | The `Enumerated` newtype is an indication that the Haskell

355+type it's applied to should be stored as a `PGenum`.

356+-}

357+newtype Enumerated enum = Enumerated {getEnumerated :: enum}

358+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

359+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

360+-- | `PGenum` @(@`LabelsPG` @hask)@

361+type instance PG (Enumerated hask) = 'PGenum (LabelsPG hask)

362+

363+{- | The `VarArray` newtype is an indication that the Haskell

364+type it's applied to should be stored as a `PGvararray`.

365+

366+>>> :kind! PG (VarArray (Vector Double))

367+PG (VarArray (Vector Double)) :: PGType

368+= 'PGvararray ('NotNull 'PGfloat8)

369+-}

370+newtype VarArray arr = VarArray {getVarArray :: arr}

371+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

372+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

373+-- | `PGvararray` @(@`NullPG` @hask)@

374+type instance PG (VarArray (Vector hask)) = 'PGvararray (NullPG hask)

375+type instance PG (VarArray [hask]) = 'PGvararray (NullPG hask)

376+

377+{- | The `FixArray` newtype is an indication that the Haskell

378+type it's applied to should be stored as a `PGfixarray`.

379+

380+>>> :kind! PG (FixArray ((Double, Double), (Double, Double)))

381+PG (FixArray ((Double, Double), (Double, Double))) :: PGType

382+= 'PGfixarray '[2, 2] ('NotNull 'PGfloat8)

383+-}

384+newtype FixArray arr = FixArray {getFixArray :: arr}

385+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

386+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

387+-- | `PGfixarray` @(@`DimPG` @hask) (@`FixPG` @hask)@

388+type instance PG (FixArray hask) = 'PGfixarray (DimPG hask) (FixPG hask)

squeal-postgresql/src/Squeal/PostgreSQL/PQ.hs+312−211

@@ -6,12 +6,12 @@ Maintainer: eitan@morphism.tech

66Stability: experimental

88This 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

1010a `Definition` and `MonadPQ` for executing a `Manipulation` or `Query`,

1111and a `PQ` type with instances for them.

1212

1313Using 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

1515application's monad transformer stack, giving it an instance of `MonadPQ`.

1616

1717This module also provides functions for retrieving rows from the `LibPQ.Result`

@@ -24,6 +24,7 @@ of executing Squeal commands.

2424 , FunctionalDependencies

2525 , FlexibleContexts

2626 , FlexibleInstances

27+ , InstanceSigs

2728 , OverloadedStrings

2829 , RankNTypes

2930 , ScopedTypeVariables

@@ -48,9 +49,7 @@ module Squeal.PostgreSQL.PQ

4849 , evalPQ

4950 , IndexedMonadTransPQ (..)

5051 , MonadPQ (..)

51− , PQRun

52− , pqliftWith

53− -- * Result

52+ -- * Results

5453 , LibPQ.Result

5554 , LibPQ.Row

5655 , ntuples

@@ -62,22 +61,33 @@ module Squeal.PostgreSQL.PQ

6261 , LibPQ.ExecStatus (..)

6362 , resultStatus

6463 , resultErrorMessage

64+ , resultErrorCode

65+ -- * Exceptions

66+ , SquealException (..)

67+ , PQState (..)

68+ , okResult

69+ , catchSqueal

70+ , handleSqueal

71+ , trySqueal

6572 ) where

6673

67−import Control.Exception.Lifted

68−import Control.Monad.Base

74+import Control.Exception (Exception, throw)

6975import Control.Monad.Except

7076import Control.Monad.Morph

71−import Control.Monad.Trans.Control

77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)

7278import Data.ByteString (ByteString)

7379import Data.Foldable

7480import Data.Function ((&))

81+import Data.Functor ((<&>))

7582import Data.Kind

76−import Data.Monoid

83+import Data.Text (pack, Text)

7784import Data.Traversable

7885import Generics.SOP

86+import PostgreSQL.Binary.Encoding (encodingBytes)

7987

88+import qualified Control.Monad.Fail as Fail

8089import qualified Database.PostgreSQL.LibPQ as LibPQ

90+import qualified PostgreSQL.Binary.Encoding as Encoding

8191

8292import Squeal.PostgreSQL.Binary

8393import Squeal.PostgreSQL.Definition

@@ -90,7 +100,6 @@ import Control.Monad.Trans.Identity

90100import Control.Monad.Trans.Reader

91101import Control.Monad.Trans.Maybe

92102import Control.Monad.Trans.Cont

93−import Control.Monad.Trans.List

94103

95104import qualified Control.Monad.Trans.State.Lazy as Lazy

96105import qualified Control.Monad.Trans.State.Strict as Strict

@@ -99,6 +108,9 @@ import qualified Control.Monad.Trans.Writer.Strict as Strict

99108import qualified Control.Monad.Trans.RWS.Lazy as Lazy

100109import qualified Control.Monad.Trans.RWS.Strict as Strict

101110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

102114{- | Makes a new connection to the database server.

103115

104116This function opens a new database connection using the parameters taken

@@ -125,22 +137,22 @@ Note that, for now, squeal doesn't offer any protection from connecting

125137with the wrong schema!

126138-}

127139connectdb

128− :: forall schema io

129− . MonadBase IO io

140+ :: forall schemas io

141+ . MonadIO io

130142 => ByteString -- ^ conninfo

131− -> io (K LibPQ.Connection schema)

132−connectdb = fmap K . liftBase . LibPQ.connectdb

143+ -> io (K LibPQ.Connection schemas)

144+connectdb = fmap K . liftIO . LibPQ.connectdb

133145

134146-- | Closes the connection to the server.

135−finish :: MonadBase IO io => K LibPQ.Connection schema -> io ()

136−finish = liftBase . LibPQ.finish . unK

147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()

148+finish = liftIO . LibPQ.finish . unK

137149

138150-- | Do `connectdb` and `finish` before and after a computation.

139151withConnection

140− :: forall schema0 schema1 io x

141− . MonadBaseControl IO io

152+ :: forall schemas0 schemas1 io x

153+ . MonadUnliftIO io

142154 => ByteString

143− -> PQ schema0 schema1 io x

155+ -> PQ schemas0 schemas1 io x

144156 -> io x

145157withConnection connString action = do

146158 K x <- bracket (connectdb connString) finish (unPQ action)

@@ -148,47 +160,47 @@ withConnection connString action = do

148160

149161-- | Safely `lowerConnection` to a smaller schema.

150162lowerConnection

151− :: K LibPQ.Connection (table ': schema)

152− -> K LibPQ.Connection schema

163+ :: K LibPQ.Connection (schema ': schemas)

164+ -> K LibPQ.Connection schemas

153165lowerConnection (K conn) = K conn

154166

155167-- | We keep track of the schema via an Atkey indexed state monad transformer,

156168-- `PQ`.

157169newtype PQ

158− (schema0 :: SchemaType)

159− (schema1 :: SchemaType)

170+ (schemas0 :: SchemasType)

171+ (schemas1 :: SchemasType)

160172 (m :: Type -> Type)

161173 (x :: Type) =

162− PQ { unPQ :: K LibPQ.Connection schema0 -> m (K x schema1) }

174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }

163175

164−instance Monad m => Functor (PQ schema0 schema1 m) where

176+instance Monad m => Functor (PQ schemas0 schemas1 m) where

165177 fmap f (PQ pq) = PQ $ \ conn -> do

166178 K x <- pq conn

167179 return $ K (f x)

168180

169−-- | Run a `PQ` and keep the result and the `Connection`.

181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.

170182runPQ

171183 :: Functor m

172− => PQ schema0 schema1 m x

173− -> K LibPQ.Connection schema0

174− -> m (x, K LibPQ.Connection schema1)

184+ => PQ schemas0 schemas1 m x

185+ -> K LibPQ.Connection schemas0

186+ -> m (x, K LibPQ.Connection schemas1)

175187runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

176188 -- K x <- pq conn

177189 -- return (x, K (unK conn))

178190

179−-- | Execute a `PQ` and discard the result but keep the `Connection`.

191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.

180192execPQ

181193 :: Functor m

182− => PQ schema0 schema1 m x

183− -> K LibPQ.Connection schema0

184− -> m (K LibPQ.Connection schema1)

194+ => PQ schemas0 schemas1 m x

195+ -> K LibPQ.Connection schemas0

196+ -> m (K LibPQ.Connection schemas1)

185197execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

186198

187−-- | Evaluate a `PQ` and discard the `Connection` but keep the result.

199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.

188200evalPQ

189201 :: Functor m

190− => PQ schema0 schema1 m x

191− -> K LibPQ.Connection schema0

202+ => PQ schemas0 schemas1 m x

203+ -> K LibPQ.Connection schemas0

192204 -> m x

193205evalPQ (PQ pq) conn = unK <$> pq conn

194206

@@ -196,60 +208,56 @@ evalPQ (PQ pq) conn = unK <$> pq conn

196208-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

197209-- An indexed monad transformer transforms a `Monad` into an indexed monad.

198210-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

199−-- support running `Definition`s using `define` and embedding a computation

200−-- in a larger schema using `pqEmbed`.

211+-- support running `Definition`s using `define`.

201212class IndexedMonadTransPQ pq where

202213

203214 -- | indexed analog of `<*>`

204215 pqAp

205216 :: Monad m

206− => pq schema0 schema1 m (x -> y)

207− -> pq schema1 schema2 m x

208− -> pq schema0 schema2 m y

217+ => pq schemas0 schemas1 m (x -> y)

218+ -> pq schemas1 schemas2 m x

219+ -> pq schemas0 schemas2 m y

209220

210221 -- | indexed analog of `join`

211222 pqJoin

212223 :: Monad m

213− => pq schema0 schema1 m (pq schema1 schema2 m y)

214− -> pq schema0 schema2 m y

224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)

225+ -> pq schemas0 schemas2 m y

215226 pqJoin pq = pq & pqBind id

216227

217228 -- | indexed analog of `=<<`

218229 pqBind

219230 :: Monad m

220− => (x -> pq schema1 schema2 m y)

221− -> pq schema0 schema1 m x

222− -> pq schema0 schema2 m y

231+ => (x -> pq schemas1 schemas2 m y)

232+ -> pq schemas0 schemas1 m x

233+ -> pq schemas0 schemas2 m y

223234

224235 -- | indexed analog of flipped `>>`

225236 pqThen

226237 :: Monad m

227− => pq schema1 schema2 m y

228− -> pq schema0 schema1 m x

229− -> pq schema0 schema2 m y

238+ => pq schemas1 schemas2 m y

239+ -> pq schemas0 schemas1 m x

240+ -> pq schemas0 schemas2 m y

230241 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

231242

232243 -- | indexed analog of `<=<`

233244 pqAndThen

234245 :: Monad m

235− => (y -> pq schema1 schema2 m z)

236− -> (x -> pq schema0 schema1 m y)

237− -> x -> pq schema0 schema2 m z

246+ => (y -> pq schemas1 schemas2 m z)

247+ -> (x -> pq schemas0 schemas1 m y)

248+ -> x -> pq schemas0 schemas2 m z

238249 pqAndThen g f x = pqBind g (f x)

239250

240− -- | Safely embed a computation in a larger schema.

241− pqEmbed

242− :: Monad m

243− => pq schema0 schema1 m x

244− -> pq (table ': schema0) (table : schema1) m x

245−

246− -- | Run a `Definition` with `LibPQ.exec`, we expect that libpq obeys the law

251+ -- | Run a `Definition` with `LibPQ.exec`.

252+ --

253+ -- It should be functorial in effect.

247254 --

248− -- @define statement1 & pqThen (define statement2) = define (statement1 >>> statement2)@

255+ -- @define id = return ()@

256+ -- @define (statement1 >>> statement2) = define statement1 & pqThen (define statement2)@

249257 define

250− :: MonadBase IO io

251− => Definition schema0 schema1

252− -> pq schema0 schema1 io (K LibPQ.Result '[])

258+ :: MonadIO io

259+ => Definition schemas0 schemas1

260+ -> pq schemas0 schemas1 io ()

253261

254262instance IndexedMonadTransPQ PQ where

255263

@@ -262,26 +270,26 @@ instance IndexedMonadTransPQ PQ where

262270 K x' <- x conn

263271 unPQ (f x') (K (unK conn))

264272

265− pqEmbed (PQ pq) = PQ $ \ (K conn) -> do

266− K x <- pq (K conn)

267− return $ K x

268−

269273 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

270− resultMaybe <- liftBase $ LibPQ.exec conn q

274+ resultMaybe <- liftIO $ LibPQ.exec conn q

271275 case resultMaybe of

272− Nothing -> error

276+ Nothing -> throw $ ResultException

273277 "define: LibPQ.exec returned no results"

274− Just result -> return $ K (K result)

278+ Just result -> K <$> okResult_ result

275279

276−{- | `MonadPQ` is an `mtl` style constraint, similar to

277−`Control.Monad.State.Class.MonadState`, for using `LibPQ` to

280+{- | `MonadPQ` is an @mtl@ style constraint, similar to

281+`Control.Monad.State.Class.MonadState`, for using `Database.PostgreSQL.LibPQ` to

278282

279283* `manipulateParams` runs a `Manipulation` with params from a type

280284 with a `ToParams` constraint. It calls `LibPQ.execParams` and

281285 doesn't afraid of anything.

282286

287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.

288+

283289* `manipulate` is like `manipulateParams` for a parameter-free statement.

284290

291+* `manipulate_` is like `manipulate` for a returning-free statement.

292+

285293* `runQueryParams` is like `manipulateParams` for query statements.

286294

287295* `runQuery` is like `runQueryParams` for a parameter-free statement.

@@ -295,11 +303,11 @@ instance IndexedMonadTransPQ PQ where

295303* `forPrepared` is a flipped `traversePrepared`

296304

297305* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

298− containers and returns unit.

306+ containers for a returning-free statement.

299307

300308* `forPrepared_` is a flipped `traversePrepared_`.

301309

302−* `liftPQ` lets you lift actions from `LibPQ` that require a connection

310+* `liftPQ` lets you lift actions from `Database.PostgreSQL.LibPQ` that require a connection

303311 into your monad.

304312

305313To define an instance, you can minimally define only `manipulateParams`,

@@ -307,305 +315,398 @@ To define an instance, you can minimally define only `manipulateParams`,

307315a default instance.

308316

309317-}

310−class Monad pq => MonadPQ schema pq | pq -> schema where

318+class Monad pq => MonadPQ schemas pq | pq -> schemas where

311319 manipulateParams

312− :: ToParams x params

313− => Manipulation schema params ys

314− -- ^ `insertRows`, `update` or `deleteFrom`

320+ :: (ToParams x params, All OidOfParam params)

321+ => Manipulation '[] schemas params ys

322+ -- ^ `insertInto`, `update` or `deleteFrom`

315323 -> x -> pq (K LibPQ.Result ys)

316324 default manipulateParams

317− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

318− => ToParams x params

319− => Manipulation schema params ys

320− -- ^ `insertRows`, `update` or `deleteFrom`

325+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

326+ => (ToParams x params, All OidOfParam params)

327+ => Manipulation '[] schemas params ys

328+ -- ^ `insertInto`, `update` or `deleteFrom`

321329 -> x -> pq (K LibPQ.Result ys)

322330 manipulateParams manipulation params = lift $

323331 manipulateParams manipulation params

324332

325− manipulate :: Manipulation schema '[] ys -> pq (K LibPQ.Result ys)

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+

340+ manipulate :: Manipulation '[] schemas '[] ys -> pq (K LibPQ.Result ys)

326341 manipulate statement = manipulateParams statement ()

327342

343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()

344+ manipulate_ = void . manipulate

345+

328346 runQueryParams

329− :: ToParams x params

330− => Query schema params ys

347+ :: (ToParams x params, All OidOfParam params)

348+ => Query '[] '[] schemas params ys

331349 -- ^ `select` and friends

332350 -> x -> pq (K LibPQ.Result ys)

333351 runQueryParams = manipulateParams . queryStatement

334352

335353 runQuery

336− :: Query schema '[] ys

354+ :: Query '[] '[] schemas '[] ys

337355 -- ^ `select` and friends

338356 -> pq (K LibPQ.Result ys)

339357 runQuery q = runQueryParams q ()

340358

341359 traversePrepared

342− :: (ToParams x params, Traversable list)

343− => Manipulation schema params ys

344− -- ^ `insertRows`, `update`, or `deleteFrom`, and friends

360+ :: (ToParams x params, Traversable list, All OidOfParam params)

361+ => Manipulation '[] schemas params ys

362+ -- ^ `insertInto`, `update`, or `deleteFrom`, and friends

345363 -> list x -> pq (list (K LibPQ.Result ys))

346364 default traversePrepared

347− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

348− => (ToParams x params, Traversable list)

349− => Manipulation schema params ys -> list x -> pq (list (K LibPQ.Result ys))

365+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

366+ => (ToParams x params, Traversable list, All OidOfParam params)

367+ => Manipulation '[] schemas params ys -> list x -> pq (list (K LibPQ.Result ys))

350368 traversePrepared manipulation params = lift $

351369 traversePrepared manipulation params

352370

353371 forPrepared

354− :: (ToParams x params, Traversable list)

372+ :: (ToParams x params, Traversable list, All OidOfParam params)

355373 => list x

356− -> Manipulation schema params ys

357− -- ^ `insertRows`, `update` or `deleteFrom`

374+ -> Manipulation '[] schemas params ys

375+ -- ^ `insertInto`, `update` or `deleteFrom`

358376 -> pq (list (K LibPQ.Result ys))

359377 forPrepared = flip traversePrepared

360378

361379 traversePrepared_

362− :: (ToParams x params, Foldable list)

363− => Manipulation schema params '[]

364− -- ^ `insertRows`, `update` or `deleteFrom`

380+ :: (ToParams x params, Foldable list, All OidOfParam params)

381+ => Manipulation '[] schemas params '[]

382+ -- ^ `insertInto`, `update` or `deleteFrom`

365383 -> list x -> pq ()

366384 default traversePrepared_

367− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

368− => (ToParams x params, Foldable list)

369− => Manipulation schema params '[]

370− -- ^ `insertRows`, `update` or `deleteFrom`

385+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

386+ => (ToParams x params, Foldable list, All OidOfParam params)

387+ => Manipulation '[] schemas params '[]

388+ -- ^ `insertInto`, `update` or `deleteFrom`

371389 -> list x -> pq ()

372390 traversePrepared_ manipulation params = lift $

373391 traversePrepared_ manipulation params

374392

375393 forPrepared_

376− :: (ToParams x params, Foldable list)

394+ :: (ToParams x params, Foldable list, All OidOfParam params)

377395 => list x

378− -> Manipulation schema params '[]

379− -- ^ `insertRows`, `update` or `deleteFrom`

396+ -> Manipulation '[] schemas params '[]

397+ -- ^ `insertInto`, `update` or `deleteFrom`

380398 -> pq ()

381399 forPrepared_ = flip traversePrepared_

382400

383401 liftPQ :: (LibPQ.Connection -> IO a) -> pq a

384402 default liftPQ

385− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

386404 => (LibPQ.Connection -> IO a) -> pq a

387405 liftPQ = lift . liftPQ

388406

389−instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)

390− => MonadPQ schema (PQ schema0 schema1 io) where

407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)

408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where

391409

392410 manipulateParams

393− (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =

411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =

394412 PQ $ \ (K conn) -> do

395413 let

396− toParam' bytes = (LibPQ.invalidOid,bytes,LibPQ.Binary)

397− params' = fmap (fmap toParam') (hcollapse (toParams @x @ps params))

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

424+ $ toParams @x @ps params

398425 q' = q <> ";"

399− resultMaybe <- liftBase $ LibPQ.execParams conn q' params' LibPQ.Binary

426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary

400427 case resultMaybe of

401− Nothing -> error

428+ Nothing -> throw $ ResultException

402429 "manipulateParams: LibPQ.execParams returned no results"

403− Just result -> return $ K (K result)

430+ Just result -> do

431+ okResult_ result

432+ return $ K (K result)

404433

405434 traversePrepared

406− (UnsafeManipulation q :: Manipulation schema xs ys) (list :: list x) =

407− PQ $ \ (K conn) -> liftBase $ do

408− let temp = "temporary_statement"

409− prepResultMaybe <- LibPQ.prepare conn temp q Nothing

435+ (UnsafeManipulation q :: Manipulation '[] schemas xs ys) (list :: list x) =

436+ PQ $ \ (K conn) -> liftIO $ do

437+ let

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

445+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

410446 case prepResultMaybe of

411− Nothing -> error

447+ Nothing -> throw $ ResultException

412448 "traversePrepared: LibPQ.prepare returned no results"

413− Just prepResult -> do

414− status <- LibPQ.resultStatus prepResult

415− unless (status == LibPQ.CommandOk) . error $

416− "traversePrepared: LibPQ.prepare status " <> show status

449+ Just prepResult -> okResult_ prepResult

417450 results <- for list $ \ params -> do

418451 let

419− toParam' bytes = (bytes,LibPQ.Binary)

452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

420453 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

421454 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

422455 case resultMaybe of

423− Nothing -> error

456+ Nothing -> throw $ ResultException

424457 "traversePrepared: LibPQ.execParams returned no results"

425− Just result -> return $ K result

458+ Just result -> do

459+ okResult_ result

460+ return $ K result

426461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

427462 case deallocResultMaybe of

428− Nothing -> error

463+ Nothing -> throw $ ResultException

429464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

430− Just deallocResult -> do

431− status <- LibPQ.resultStatus deallocResult

432− unless (status == LibPQ.CommandOk) . error $

433− "traversePrepared: DEALLOCATE status " <> show status

465+ Just deallocResult -> okResult_ deallocResult

434466 return (K results)

435467

436468 traversePrepared_

437− (UnsafeManipulation q :: Manipulation schema xs '[]) (list :: list x) =

438− PQ $ \ (K conn) -> liftBase $ do

439− let temp = "temporary_statement"

440− prepResultMaybe <- LibPQ.prepare conn temp q Nothing

469+ (UnsafeManipulation q :: Manipulation '[] schemas xs '[]) (list :: list x) =

470+ PQ $ \ (K conn) -> liftIO $ do

471+ let

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

479+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

441480 case prepResultMaybe of

442− Nothing -> error

481+ Nothing -> throw $ ResultException

443482 "traversePrepared_: LibPQ.prepare returned no results"

444− Just prepResult -> do

445− status <- LibPQ.resultStatus prepResult

446− unless (status == LibPQ.CommandOk) . error $

447− "traversePrepared: LibPQ.prepare status " <> show status

483+ Just prepResult -> okResult_ prepResult

448484 for_ list $ \ params -> do

449485 let

450− toParam' bytes = (bytes,LibPQ.Binary)

486+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

451487 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

452488 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

453489 case resultMaybe of

454− Nothing -> error

490+ Nothing -> throw $ ResultException

455491 "traversePrepared_: LibPQ.execParams returned no results"

456− Just _result -> return ()

492+ Just result -> okResult_ result

457493 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

458494 case deallocResultMaybe of

459− Nothing -> error

495+ Nothing -> throw $ ResultException

460496 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

461− Just deallocResult -> do

462− status <- LibPQ.resultStatus deallocResult

463− unless (status == LibPQ.CommandOk) . error $

464− "traversePrepared: DEALLOCATE status " <> show status

497+ Just deallocResult -> okResult_ deallocResult

465498 return (K ())

466499

467500 liftPQ pq = PQ $ \ (K conn) -> do

468− y <- liftBase $ pq conn

501+ y <- liftIO $ pq conn

469502 return (K y)

470503

471−instance MonadPQ schema m => MonadPQ schema (IdentityT m)

472−instance MonadPQ schema m => MonadPQ schema (ReaderT r m)

473−instance MonadPQ schema m => MonadPQ schema (Strict.StateT s m)

474−instance MonadPQ schema m => MonadPQ schema (Lazy.StateT s m)

475−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.WriterT w m)

476−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.WriterT w m)

477−instance MonadPQ schema m => MonadPQ schema (MaybeT m)

478−instance MonadPQ schema m => MonadPQ schema (ExceptT e m)

479−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.RWST r w s m)

480−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.RWST r w s m)

481−instance MonadPQ schema m => MonadPQ schema (ContT r m)

482−instance MonadPQ schema m => MonadPQ schema (ListT m)

483−

484−instance (Monad m, schema0 ~ schema1)

485− => Applicative (PQ schema0 schema1 m) where

504+instance MonadPQ schemas m => MonadPQ schemas (IdentityT m)

505+instance MonadPQ schemas m => MonadPQ schemas (ReaderT r m)

506+instance MonadPQ schemas m => MonadPQ schemas (Strict.StateT s m)

507+instance MonadPQ schemas m => MonadPQ schemas (Lazy.StateT s m)

508+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.WriterT w m)

509+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.WriterT w m)

510+instance MonadPQ schemas m => MonadPQ schemas (MaybeT m)

511+instance MonadPQ schemas m => MonadPQ schemas (ExceptT e m)

512+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.RWST r w s m)

513+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.RWST r w s m)

514+instance MonadPQ schemas m => MonadPQ schemas (ContT r m)

515+

516+instance (Monad m, schemas0 ~ schemas1)

517+ => Applicative (PQ schemas0 schemas1 m) where

486518 pure x = PQ $ \ _conn -> pure (K x)

487519 (<*>) = pqAp

488520

489−instance (Monad m, schema0 ~ schema1)

490− => Monad (PQ schema0 schema1 m) where

521+instance (Monad m, schemas0 ~ schemas1)

522+ => Monad (PQ schemas0 schemas1 m) where

491523 return = pure

492524 (>>=) = flip pqBind

493525

494−instance schema0 ~ schema1 => MFunctor (PQ schema0 schema1) where

526+instance (Monad m, schemas0 ~ schemas1)

527+ => Fail.MonadFail (PQ schemas0 schemas1 m) where

528+ fail = Fail.fail

529+

530+instance schemas0 ~ schemas1 => MFunctor (PQ schemas0 schemas1) where

495531 hoist f (PQ pq) = PQ (f . pq)

496532

497−instance schema0 ~ schema1 => MonadTrans (PQ schema0 schema1) where

533+instance schemas0 ~ schemas1 => MonadTrans (PQ schemas0 schemas1) where

498534 lift m = PQ $ \ _conn -> do

499535 x <- m

500536 return (K x)

501537

502−instance schema0 ~ schema1 => MMonad (PQ schema0 schema1) where

538+instance schemas0 ~ schemas1 => MMonad (PQ schemas0 schemas1) where

503539 embed f (PQ pq) = PQ $ \ conn -> do

504540 evalPQ (f (pq conn)) conn

505541

506−instance (MonadBase b m, schema0 ~ schema1)

507− => MonadBase b (PQ schema0 schema1 m) where

508− liftBase = lift . liftBase

542+instance (MonadIO m, schema0 ~ schema1)

543+ => MonadIO (PQ schema0 schema1 m) where

544+ liftIO = lift . liftIO

509545

510−-- | A snapshot of the state of a `PQ` computation.

511−type PQRun schema =

512− forall m x. Monad m => PQ schema schema m x -> m (K x schema)

513−

514−-- | Helper function in defining `MonadBaseControl` instance for `PQ`.

515−pqliftWith :: Functor m => (PQRun schema -> m a) -> PQ schema schema m a

516−pqliftWith f = PQ $ \ conn ->

517− fmap K (f $ \ pq -> unPQ pq conn)

518−

519−instance (MonadBaseControl b m, schema0 ~ schema1)

520− => MonadBaseControl b (PQ schema0 schema1 m) where

521− type StM (PQ schema0 schema1 m) x = StM m (K x schema0)

522− liftBaseWith f =

523− pqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

524− restoreM = PQ . const . restoreM

546+instance (MonadUnliftIO m, schemas0 ~ schemas1)

547+ => MonadUnliftIO (PQ schemas0 schemas1 m) where

548+ withRunInIO

549+ :: ((forall a . PQ schemas0 schema1 m a -> IO a) -> IO b)

550+ -> PQ schemas0 schema1 m b

551+ withRunInIO inner = PQ $ \conn ->

552+ withRunInIO $ \(run :: (forall x . m x -> IO x)) ->

553+ K <$> inner (\pq -> run $ unK <$> unPQ pq conn)

525554

526555-- | Get a row corresponding to a given row number from a `LibPQ.Result`,

527556-- throwing an exception if the row number is out of bounds.

528557getRow

529− :: (FromRow columns y, MonadBase IO io)

558+ :: (FromRow columns y, MonadIO io)

530559 => LibPQ.Row

531560 -- ^ row number

532561 -> K LibPQ.Result columns

533562 -- ^ result

534563 -> io y

535−getRow r (K result :: K LibPQ.Result columns) = liftBase $ do

564+getRow r (K result :: K LibPQ.Result columns) = liftIO $ do

536565 numRows <- LibPQ.ntuples result

537− when (numRows < r) $ error $

538− "getRow: expected at least " <> show r <> "rows but only saw "

539− <> show numRows

566+ when (numRows < r) $ throw $ ResultException $

567+ "getRow: expected at least " <> pack (show r) <> "rows but only saw "

568+ <> pack (show numRows)

540569 let len = fromIntegral (lengthSList (Proxy @columns))

541570 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

542571 case fromList row' of

543− Nothing -> error "getRow: found unexpected length"

544− Just row -> return $ fromRow @columns row

572+ Nothing -> throw $ ResultException "getRow: found unexpected length"

573+ Just row -> case fromRow @columns row of

574+ Left parseError -> throw $ ParseException $ "getRow: " <> parseError

575+ Right y -> return y

545576

546577-- | Intended to be used for unfolding in streaming libraries, `nextRow`

547578-- takes a total number of rows (which can be found with `ntuples`)

548579-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,

549580-- otherwise returning the row along with the next row number.

550581nextRow

551− :: (FromRow columns y, MonadBase IO io)

582+ :: (FromRow columns y, MonadIO io)

552583 => LibPQ.Row -- ^ total number of rows

553584 -> K LibPQ.Result columns -- ^ result

554585 -> LibPQ.Row -- ^ row number

555586 -> io (Maybe (LibPQ.Row,y))

556587nextRow total (K result :: K LibPQ.Result columns) r

557− = liftBase $ if r >= total then return Nothing else do

588+ = liftIO $ if r >= total then return Nothing else do

558589 let len = fromIntegral (lengthSList (Proxy @columns))

559590 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

560591 case fromList row' of

561− Nothing -> error "nextRow: found unexpected length"

562− Just row -> return $ Just (r+1, fromRow @columns row)

592+ Nothing -> throw $ ResultException "nextRow: found unexpected length"

593+ Just row -> case fromRow @columns row of

594+ Left parseError -> throw $ ParseException $ "nextRow: " <> parseError

595+ Right y -> return $ Just (r+1, y)

563596

564597-- | Get all rows from a `LibPQ.Result`.

565598getRows

566− :: (FromRow columns y, MonadBase IO io)

599+ :: (FromRow columns y, MonadIO io)

567600 => K LibPQ.Result columns -- ^ result

568601 -> io [y]

569−getRows (K result :: K LibPQ.Result columns) = liftBase $ do

602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do

570603 let len = fromIntegral (lengthSList (Proxy @columns))

571604 numRows <- LibPQ.ntuples result

572605 for [0 .. numRows - 1] $ \ r -> do

573606 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

574607 case fromList row' of

575− Nothing -> error "getRows: found unexpected length"

576− Just row -> return $ fromRow @columns row

608+ Nothing -> throw $ ResultException "getRows: found unexpected length"

609+ Just row -> case fromRow @columns row of

610+ Left parseError -> throw $ ParseException $ "getRows: " <> parseError

611+ Right y -> return y

577612

578613-- | Get the first row if possible from a `LibPQ.Result`.

579614firstRow

580− :: (FromRow columns y, MonadBase IO io)

615+ :: (FromRow columns y, MonadIO io)

581616 => K LibPQ.Result columns -- ^ result

582617 -> io (Maybe y)

583−firstRow (K result :: K LibPQ.Result columns) = liftBase $ do

618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do

584619 numRows <- LibPQ.ntuples result

585620 if numRows <= 0 then return Nothing else do

586621 let len = fromIntegral (lengthSList (Proxy @columns))

587622 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]

588623 case fromList row' of

589− Nothing -> error "firstRow: found unexpected length"

590− Just row -> return . Just $ fromRow @columns row

624+ Nothing -> throw $ ResultException "firstRow: found unexpected length"

625+ Just row -> case fromRow @columns row of

626+ Left parseError -> throw $ ParseException $ "firstRow: " <> parseError

627+ Right y -> return $ Just y

591628

592629-- | Lifts actions on results from @LibPQ@.

593630liftResult

594− :: MonadBase IO io

631+ :: MonadIO io

595632 => (LibPQ.Result -> IO x)

596633 -> K LibPQ.Result results -> io x

597−liftResult f (K result) = liftBase $ f result

634+liftResult f (K result) = liftIO $ f result

598635

599636-- | Returns the number of rows (tuples) in the query result.

600−ntuples :: MonadBase IO io => K LibPQ.Result columns -> io LibPQ.Row

637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row

601638ntuples = liftResult LibPQ.ntuples

602639

603640-- | Returns the result status of the command.

604−resultStatus :: MonadBase IO io => K LibPQ.Result results -> io LibPQ.ExecStatus

641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus

605642resultStatus = liftResult LibPQ.resultStatus

606643

607644-- | Returns the error message most recently generated by an operation

608645-- on the connection.

609646resultErrorMessage

610− :: MonadBase IO io => K LibPQ.Result results -> io (Maybe ByteString)

647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)

611648resultErrorMessage = liftResult LibPQ.resultErrorMessage

649+

650+-- | Returns the error code most recently generated by an operation

651+-- on the connection.

652+--

653+-- https://www.postgresql.org/docs/current/static/errcodes-appendix.html

654+resultErrorCode

655+ :: MonadIO io

656+ => K LibPQ.Result results

657+ -> io (Maybe ByteString)

658+resultErrorCode = liftResult (flip LibPQ.resultErrorField LibPQ.DiagSqlstate)

659+

660+-- | the state of LibPQ

661+data PQState = PQState

662+ { sqlExecStatus :: LibPQ.ExecStatus

663+ , sqlStateCode :: Maybe ByteString

664+ -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html

665+ , sqlErrorMessage :: Maybe ByteString

666+ } deriving (Eq, Show)

667+

668+-- | `Exception`s that can be thrown by Squeal.

669+data SquealException

670+ = PQException PQState

671+ | ResultException Text

672+ | ParseException Text

673+ deriving (Eq, Show)

674+instance Exception SquealException

675+

676+okResult_ :: MonadIO io => LibPQ.Result -> io ()

677+okResult_ result = liftIO $ do

678+ status <- LibPQ.resultStatus result

679+ case status of

680+ LibPQ.CommandOk -> return ()

681+ LibPQ.TuplesOk -> return ()

682+ _ -> do

683+ stateCode <- LibPQ.resultErrorField result LibPQ.DiagSqlstate

684+ msg <- LibPQ.resultErrorMessage result

685+ throw . PQException $ PQState status stateCode msg

686+

687+-- | Check if a `LibPQ.Result`'s status is either `LibPQ.CommandOk`

688+-- or `LibPQ.TuplesOk` otherwise `throw` a `PQException`.

689+okResult :: MonadIO io => K LibPQ.Result row -> io ()

690+okResult = okResult_ . unK

691+

692+-- | Catch `SquealException`s.

693+catchSqueal

694+ :: MonadUnliftIO io

695+ => io a

696+ -> (SquealException -> io a) -- ^ handler

697+ -> io a

698+catchSqueal = catch

699+

700+-- | Handle `SquealException`s.

701+handleSqueal

702+ :: MonadUnliftIO io

703+ => (SquealException -> io a) -- ^ handler

704+ -> io a -> io a

705+handleSqueal = handle

706+

707+-- | `Either` return a `SquealException` or a result.

708+trySqueal

709+ :: MonadUnliftIO io

710+ => io a

711+ -> io (Either SquealException a)

712+trySqueal = try

squeal-postgresql/src/Squeal/PostgreSQL/Pool.hs+69−79

@@ -1,17 +1,40 @@

11{-|

2−Module: Squeal.PostgreSQL.Definition

3−Description: Pooled connections

2+Module: Squeal.PostgreSQL.Pool

3+Description: Connection pools

44Copyright: (c) Eitan Chatav, 2017

55Maintainer: eitan@morphism.tech

66Stability: experimental

8−A `MonadPQ` for pooled connections.

8+Connection pools.

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

931-}

1032

1133{-# LANGUAGE

1234 DeriveFunctor

1335 , FlexibleContexts

1436 , FlexibleInstances

37+ , InstanceSigs

1538 , MultiParamTypeClasses

1639 , RankNTypes

1740 , ScopedTypeVariables

@@ -22,34 +45,24 @@ A `MonadPQ` for pooled connections.

2245

2346module Squeal.PostgreSQL.Pool

2447 ( -- * Pools

25− PoolPQ (..)

48+ Pool

2649 , createConnectionPool

27− , Pool

28− , destroyAllResources

29− , PoolPQRun

30− , poolpqliftWith

50+ , usingConnectionPool

51+ , destroyConnectionPool

3152 ) where

3253

33−import Control.Monad.Base

34−import Control.Monad.Trans

35−import Control.Monad.Trans.Control

3654import Data.ByteString

37−import Data.Pool

3855import Data.Time

39−import Generics.SOP (K(..))

56+import Generics.SOP (K(..), unK)

57+import UnliftIO (MonadUnliftIO (..))

58+import UnliftIO.Pool (Pool, createPool, destroyAllResources, withResource)

4059

4160import Squeal.PostgreSQL.PQ

42−import Squeal.PostgreSQL.Schema

43−

44−-- | `PoolPQ` @schema@ should be a drop-in replacement for `PQ` @schema schema@.

45−newtype PoolPQ (schema :: SchemaType) m x =

46− PoolPQ { runPoolPQ :: Pool (K Connection schema) -> m x }

47− deriving Functor

4861

4962-- | Create a striped pool of connections.

5063-- 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.

5164createConnectionPool

52− :: MonadBase IO io

65+ :: MonadUnliftIO io

5366 => ByteString

5467 -- ^ The passed string can be empty to use all default parameters, or it can

5568 -- contain one or more parameter settings separated by whitespace.

@@ -65,68 +78,45 @@ createConnectionPool

6578 -> Int

6679 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

6780 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

68− -> io (Pool (K Connection schema))

69−createConnectionPool conninfo stripes idle maxResrc = liftBase $

81+ -> io (Pool (K Connection schemas))

82+createConnectionPool conninfo stripes idle maxResrc =

7083 createPool (connectdb conninfo) finish stripes idle maxResrc

7184

72−-- | `Applicative` instance for `PoolPQ`.

73−instance Monad m => Applicative (PoolPQ schema m) where

74− pure x = PoolPQ $ \ _ -> pure x

75− PoolPQ f <*> PoolPQ x = PoolPQ $ \ pool -> do

76− f' <- f pool

77− x' <- x pool

78− return $ f' x'

79−

80−-- | `Monad` instance for `PoolPQ`.

81−instance Monad m => Monad (PoolPQ schema m) where

82− return = pure

83− PoolPQ x >>= f = PoolPQ $ \ pool -> do

84− x' <- x pool

85− runPoolPQ (f x') pool

86−

87−-- | `MonadTrans` instance for `PoolPQ`.

88−instance MonadTrans (PoolPQ schema) where

89− lift m = PoolPQ $ \ _pool -> m

90−

91−-- | `MonadBase` instance for `PoolPQ`.

92−instance MonadBase b m => MonadBase b (PoolPQ schema m) where

93− liftBase = lift . liftBase

85+{-|

86+Temporarily take a connection from a `Pool`, perform an action with it,

87+and return it to the pool afterwards.

9488

95−-- | `MonadPQ` instance for `PoolPQ`.

96−instance MonadBaseControl IO io => MonadPQ schema (PoolPQ schema io) where

97− manipulateParams manipulation params = PoolPQ $ \ pool -> do

98− withResource pool $ \ conn -> do

99− (K result :: K (K Result ys) schema) <- flip unPQ conn $

100− manipulateParams manipulation params

101− return result

102− traversePrepared manipulation params = PoolPQ $ \ pool ->

103− withResource pool $ \ conn -> do

104− (K result :: K (list (K Result ys)) schema) <- flip unPQ conn $

105− traversePrepared manipulation params

106− return result

107− traversePrepared_ manipulation params = PoolPQ $ \ pool -> do

108− withResource pool $ \ conn -> do

109− (_ :: K () schema) <- flip unPQ conn $

110− traversePrepared_ manipulation params

111− return ()

112− liftPQ m = PoolPQ $ \ pool ->

113− withResource pool $ \ conn -> do

114− (K result :: K result schema) <- flip unPQ conn $

115− liftPQ m

116− return result

89+If the pool has an idle connection available, it is used immediately.

90+Otherwise, if the maximum number of connections has not yet been reached,

91+a new connection is created and used.

92+If the maximum number of connections has been reached, this function blocks

93+until a connection becomes available.

94+-}

95+usingConnectionPool

96+ :: MonadUnliftIO io

97+ => Pool (K Connection schemas) -- ^ pool

98+ -> PQ schemas schemas io x -- ^ session

99+ -> io x

100+usingConnectionPool pool (PQ session) = unK <$> withResource pool session

117101

118−-- | A snapshot of the state of a `PoolPQ` computation.

119−type PoolPQRun schema =

120− forall m x. Monad m => PoolPQ schema m x -> m x

102+{- |

103+Destroy all connections in all stripes in the pool.

104+Note that this will ignore any exceptions in the destroy function.

121105

122−-- | Helper function in defining `MonadBaseControl` instance for `PoolPQ`.

123−poolpqliftWith :: Functor m => (PoolPQRun schema -> m a) -> PoolPQ schema m a

124−poolpqliftWith f = PoolPQ $ \ pool ->

125− (f $ \ pq -> runPoolPQ pq pool)

106+This function is useful when you detect that all connections

107+in the pool are broken. For example after a database has been

108+restarted all connections opened before the restart will be broken.

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.

126112

127−-- | `MonadBaseControl` instance for `PoolPQ`.

128−instance MonadBaseControl b m => MonadBaseControl b (PoolPQ schema m) where

129− type StM (PoolPQ schema m) x = StM m x

130− liftBaseWith f =

131− poolpqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

132− restoreM = PoolPQ . const . restoreM

113+Another use-case for this function is that when you know you are done

114+with the pool you can destroy all idle connections immediately

115+instead of waiting on the garbage collector to destroy them,

116+thus freeing up those connections sooner.

117+-}

118+destroyConnectionPool

119+ :: MonadUnliftIO io

120+ => Pool (K Connection schemas) -- ^ pool

121+ -> io ()

122+destroyConnectionPool = destroyAllResources

squeal-postgresql/src/Squeal/PostgreSQL/Query.hs+678−439

@@ -1,7 +1,7 @@

11{-|

22Module: Squeal.PostgreSQL.Query

33Description: Squeal queries

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

55Maintainer: eitan@morphism.tech

66Stability: experimental

@@ -9,70 +9,81 @@ Squeal queries.

99-}

1010

1111{-# LANGUAGE

12− DeriveGeneric

12+ ConstraintKinds

13+ , DeriveGeneric

1314 , FlexibleContexts

15+ , FlexibleInstances

1416 , GADTs

1517 , GeneralizedNewtypeDeriving

1618 , LambdaCase

19+ , MultiParamTypeClasses

20+ , OverloadedLabels

1721 , OverloadedStrings

22+ , QuantifiedConstraints

23+ , ScopedTypeVariables

1824 , StandaloneDeriving

25+ , TypeApplications

26+ , TypeFamilies

1927 , TypeInType

2028 , TypeOperators

21−#-}

29+ , RankNTypes

30+ , UndecidableInstances

31+ #-}

2232

2333module Squeal.PostgreSQL.Query

2434 ( -- * Queries

25− Query (UnsafeQuery, renderQuery)

35+ Query_

36+ , Query (..)

37+ -- ** Select

38+ , select

39+ , select_

40+ , selectDistinct

41+ , selectDistinct_

42+ , selectDistinctOn

43+ , selectDistinctOn_

44+ , Selection (..)

45+ -- ** Values

46+ , values

47+ , values_

48+ -- ** Set Operations

2649 , union

2750 , unionAll

2851 , intersect

2952 , intersectAll

3053 , except

3154 , exceptAll

32− -- * Select

33− , select

34− , selectDistinct

35− , selectStar

36− , selectDistinctStar

37− , selectDotStar

38− , selectDistinctDotStar

39− , values

40− , values_

55+ -- ** With

56+ , With (..)

57+ , CommonTableExpression (..)

58+ , withRecursive

4159 -- * Table Expressions

4260 , TableExpression (..)

43− , renderTableExpression

4461 , from

4562 , where_

46− , group

63+ , groupBy

4764 , having

48− , orderBy

4965 , limit

5066 , offset

51− -- * From

67+ -- * From Clauses

5268 , FromClause (..)

5369 , table

5470 , subquery

5571 , view

72+ , common

5673 , crossJoin

5774 , innerJoin

5875 , leftOuterJoin

5976 , rightOuterJoin

6077 , fullOuterJoin

6178 -- * Grouping

62− , By (By, By2)

63− , renderBy

64− , GroupByClause (NoGroups, Group)

65− , renderGroupByClause

66− , HavingClause (NoHaving, Having)

67− , renderHavingClause

68− -- * Sorting

69− , SortExpression (..)

70− , renderSortExpression

79+ , By (..)

80+ , GroupByClause (..)

81+ , HavingClause (..)

7182 ) where

7283

7384import Control.DeepSeq

7485import Data.ByteString (ByteString)

75−import Data.Monoid hiding (All)

86+import Data.Kind (Type)

7687import Data.String

7788import Data.Word

7889import Generics.SOP hiding (from)

@@ -80,25 +91,76 @@ import GHC.TypeLits

8091

8192import qualified GHC.Generics as GHC

8293

94+import Squeal.PostgreSQL.Alias

8395import 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

84101import Squeal.PostgreSQL.Render

85102import Squeal.PostgreSQL.Schema

86103

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+

87111{- |

88−The process of retrieving or the command to retrieve data from a database

89−is called a `Query`. The `select`, `selectStar`, `selectDotStar`,

90−`selectDistinct`, `selectDistinctStar` and `selectDistinctDotStar` commands

91−are used to specify queries.

112+The process of retrieving or the command to retrieve data from

113+a database is called a `Query`.

114+

115+The general `Query` type is parameterized by

116+

117+* @outer :: FromType@ - outer scope for a correlated subquery,

118+* @commons :: FromType@ - scope for all `common` table expressions,

119+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

120+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

121+* @row :: RowType@ - return type of the `Query`.

122+-}

123+newtype Query

124+ (outer :: FromType)

125+ (commons :: FromType)

126+ (schemas :: SchemasType)

127+ (params :: [NullityType])

128+ (row :: RowType)

129+ = UnsafeQuery { renderQuery :: ByteString }

130+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

131+instance RenderSQL (Query outer commons schemas params row) where renderSQL = renderQuery

132+

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+:}

92155

93156simple query:

94157

158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

95160>>> :{

96161let

97− query :: Query

98− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

99− '[]

100− '["col" ::: 'Null 'PGint4]

101− query = selectStar (from (table #tab))

162+ query :: Query_ (Public Schema) () (Row Int32 Int32)

163+ query = select Star (from (table #tab))

102164in printSQL query

103165:}

104166SELECT * FROM "tab" AS "tab"

@@ -107,34 +169,22 @@ restricted query:

107169

108170>>> :{

109171let

110− query :: Query

111− '[ "tab" ::: 'Table ('[] :=>

112− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

113− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

114− '[]

115− '[ "sum" ::: 'NotNull 'PGint4

116− , "col1" ::: 'NotNull 'PGint4 ]

172+ query :: Query_ (Public Schema) () (Row Int32 Int32)

117173 query =

118− select

119− ((#col1 + #col2) `As` #sum :* #col1 :* Nil)

174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)

120175 ( from (table #tab)

121176 & where_ (#col1 .> #col2)

122177 & where_ (#col2 .> 0) )

123178in printSQL query

124179:}

125−SELECT ("col1" + "col2") AS "sum", "col1" AS "col1" FROM "tab" AS "tab" WHERE (("col1" > "col2") AND ("col2" > 0))

180+SELECT ("col1" + "col2") AS "col1", "col1" AS "col2" FROM "tab" AS "tab" WHERE (("col1" > "col2") AND ("col2" > 0))

126181

127182subquery:

128183

129184>>> :{

130185let

131− query :: Query

132− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

133− '[]

134− '["col" ::: 'Null 'PGint4]

135− query =

136− selectStar

137− (from (subquery (selectStar (from (table #tab)) `As` #sub)))

186+ query :: Query_ (Public Schema) () (Row Int32 Int32)

187+ query = select Star (from (subquery (select Star (from (table #tab)) `as` #sub)))

138188in printSQL query

139189:}

140190SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"

@@ -143,12 +193,8 @@ limits and offsets:

143193

144194>>> :{

145195let

146− query :: Query

147− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

148− '[]

149− '["col" ::: 'Null 'PGint4]

150− query = selectStar

151− (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)

196+ query :: Query_ (Public Schema) () (Row Int32 Int32)

197+ query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)

152198in printSQL query

153199:}

154200SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4

@@ -157,276 +203,426 @@ parameterized query:

157203

158204>>> :{

159205let

160− query :: Query

161− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8])]

162− '[ 'NotNull 'PGfloat8]

163− '["col" ::: 'NotNull 'PGfloat8]

164− query = selectStar

165− (from (table #tab) & where_ (#col .> param @1))

206+ query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)

207+ query = select Star (from (table #tab) & where_ (#col1 .> param @1))

166208in printSQL query

167209:}

168−SELECT * FROM "tab" AS "tab" WHERE ("col" > ($1 :: float8))

210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))

169211

170212aggregation query:

171213

172214>>> :{

173215let

174− query :: Query

175− '[ "tab" ::: 'Table ('[] :=>

176− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

177− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

178− '[]

179− '[ "sum" ::: 'NotNull 'PGint4

180− , "col1" ::: 'NotNull 'PGint4 ]

216+ query :: Query_ (Public Schema) () (Row Int64 Int32)

181217 query =

182− select (sum_ #col2 `As` #sum :* #col1 :* Nil)

183− ( from (table (#tab `As` #table1))

184− & group (By #col1 :* Nil)

185− & having (#col1 + sum_ #col2 .> 1) )

218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)

219+ ( from (table (#tab `as` #table1))

220+ & groupBy #col1

221+ & having (sum_ (Distinct #col2) .> 1) )

186222in printSQL query

187223:}

188−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)

189225

190226sorted query:

191227

192228>>> :{

193229let

194− query :: Query

195− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

196− '[]

197− '["col" ::: 'Null 'PGint4]

198− query = selectStar

199− (from (table #tab) & orderBy [#col & AscNullsFirst])

230+ query :: Query_ (Public Schema) () (Row Int32 Int32)

231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])

200232in printSQL query

201233:}

202−SELECT * FROM "tab" AS "tab" ORDER BY "col" ASC NULLS FIRST

234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC

203235

204236joins:

205237

206−>>> :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+

207273>>> :{

208274let

209− query :: Query

210− '[ "orders" ::: 'Table (

211− '["pk_orders" ::: PrimaryKey '["id"]

212− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]

213− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>

214− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

215− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4

216− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4

217− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4

218− ])

219− , "customers" ::: 'Table (

220− '["pk_customers" ::: PrimaryKey '["id"]] :=>

221− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

222− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

223− ])

224− , "shippers" ::: 'Table (

225− '["pk_shippers" ::: PrimaryKey '["id"]] :=>

226− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

227− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

228− ])

229− ]

230− '[]

231− '[ "order_price" ::: 'NotNull 'PGfloat4

232− , "customer_name" ::: 'NotNull 'PGtext

233− , "shipper_name" ::: 'NotNull 'PGtext

234− ]

235− query = select

236− ( #o ! #price `As` #order_price :*

237− #c ! #name `As` #customer_name :*

238− #s ! #name `As` #shipper_name :* Nil )

239− ( from (table (#orders `As` #o)

240− & innerJoin (table (#customers `As` #c))

275+ query :: Query_ (Public OrdersSchema) () Order

276+ query = select_

277+ ( #o ! #price `as` #price :*

278+ #c ! #name `as` #customerName :*

279+ #s ! #name `as` #shipperName )

280+ ( from (table (#orders `as` #o)

281+ & innerJoin (table (#customers `as` #c))

241282 (#o ! #customer_id .== #c ! #id)

242− & innerJoin (table (#shippers `As` #s))

283+ & innerJoin (table (#shippers `as` #s))

243284 (#o ! #shipper_id .== #s ! #id)) )

244285in printSQL query

245286:}

246−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")

247288

248289self-join:

249290

250291>>> :{

251292let

252− query :: Query

253− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

254− '[]

255− '["col" ::: 'Null 'PGint4]

256− query = selectDotStar #t1

257− (from (table (#tab `As` #t1) & crossJoin (table (#tab `As` #t2))))

293+ query :: Query_ (Public Schema) () (Row Int32 Int32)

294+ query = select

295+ (#t1 & DotStar)

296+ (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))

258297in printSQL query

259298:}

260299SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"

261300

301+value queries:

302+

303+>>> :{

304+let

305+ query :: Query_ schemas () (Row String Bool)

306+ query = values

307+ ("true" `as` #col1 :* true `as` #col2)

308+ ["false" `as` #col1 :* false `as` #col2]

309+in printSQL query

310+:}

311+SELECT * FROM (VALUES (E'true', TRUE), (E'false', FALSE)) AS t ("col1", "col2")

312+

262313set operations:

263314

264315>>> :{

265316let

266− query :: Query

267− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

268− '[]

269− '["col" ::: 'Null 'PGint4]

270− query =

271− selectStar (from (table #tab))

272− `unionAll`

273− selectStar (from (table #tab))

317+ query :: Query_ (Public Schema) () (Row Int32 Int32)

318+ query = select Star (from (table #tab)) `unionAll` select Star (from (table #tab))

274319in printSQL query

275320:}

276321(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")

322+

323+with queries:

324+

325+>>> :{

326+let

327+ query :: Query_ (Public Schema) () (Row Int32 Int32)

328+ query = with (

329+ select Star (from (table #tab)) `as` #cte1 :>>

330+ select Star (from (common #cte1)) `as` #cte2

331+ ) (select Star (from (common #cte2)))

332+in printSQL query

333+:}

334+WITH "cte1" AS (SELECT * FROM "tab" AS "tab"), "cte2" AS (SELECT * FROM "cte1" AS "cte1") SELECT * FROM "cte2" AS "cte2"

335+

336+window function queries

337+

338+>>> :{

339+let

340+ query :: Query_ (Public Schema) () (Row Int32 Int64)

341+ query = select

342+ (#col1 & Also (rank `as` #col2 `Over` (partitionBy #col1 & orderBy [#col2 & Asc])))

343+ (from (table #tab))

344+in printSQL query

345+:}

346+SELECT "col1" AS "col1", rank() OVER (PARTITION BY "col1" ORDER BY "col2" ASC) AS "col2" FROM "tab" AS "tab"

347+

348+correlated subqueries

349+

350+>>> :{

351+let

352+ query :: Query_ (Public Schema) () (Only Int32)

353+ query =

354+ select (#col1 `as` #fromOnly) (from (table (#tab `as` #t1))

355+ & where_ (exists (

356+ select Star (from (table (#tab `as` #t2))

357+ & where_ (#t2 ! #col2 .== #t1 ! #col1)))))

358+in printSQL query

359+:}

360+SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))

361+

277362-}

278−newtype Query

279− (schema :: SchemaType)

280− (params :: [NullityType])

281− (columns :: RelationType)

282− = UnsafeQuery { renderQuery :: ByteString }

283− deriving (GHC.Generic,Show,Eq,Ord,NFData)

284−instance RenderSQL (Query schema params columns) where renderSQL = renderQuery

363+type family Query_

364+ (schemas :: SchemasType)

365+ (parameters :: Type)

366+ (row :: Type) where

367+ Query_ schemas params row =

368+ Query '[] '[] schemas (TuplePG params) (RowPG row)

285369

286370-- | The results of two queries can be combined using the set operation

287371-- `union`. Duplicate rows are eliminated.

288372union

289− :: Query schema params columns

290− -> Query schema params columns

291− -> Query schema params columns

373+ :: Query outer commons schemas params columns

374+ -> Query outer commons schemas params columns

375+ -> Query outer commons schemas params columns

292376q1 `union` q2 = UnsafeQuery $

293− parenthesized (renderQuery q1)

377+ parenthesized (renderSQL q1)

294378 <+> "UNION"

295− <+> parenthesized (renderQuery q2)

379+ <+> parenthesized (renderSQL q2)

296380

297381-- | The results of two queries can be combined using the set operation

298382-- `unionAll`, the disjoint union. Duplicate rows are retained.

299383unionAll

300− :: Query schema params columns

301− -> Query schema params columns

302− -> Query schema params columns

384+ :: Query outer commons schemas params columns

385+ -> Query outer commons schemas params columns

386+ -> Query outer commons schemas params columns

303387q1 `unionAll` q2 = UnsafeQuery $

304− parenthesized (renderQuery q1)

388+ parenthesized (renderSQL q1)

305389 <+> "UNION" <+> "ALL"

306− <+> parenthesized (renderQuery q2)

390+ <+> parenthesized (renderSQL q2)

307391

308392-- | The results of two queries can be combined using the set operation

309393-- `intersect`, the intersection. Duplicate rows are eliminated.

310394intersect

311− :: Query schema params columns

312− -> Query schema params columns

313− -> Query schema params columns

395+ :: Query outer commons schemas params columns

396+ -> Query outer commons schemas params columns

397+ -> Query outer commons schemas params columns

314398q1 `intersect` q2 = UnsafeQuery $

315− parenthesized (renderQuery q1)

399+ parenthesized (renderSQL q1)

316400 <+> "INTERSECT"

317− <+> parenthesized (renderQuery q2)

401+ <+> parenthesized (renderSQL q2)

318402

319403-- | The results of two queries can be combined using the set operation

320404-- `intersectAll`, the intersection. Duplicate rows are retained.

321405intersectAll

322− :: Query schema params columns

323− -> Query schema params columns

324− -> Query schema params columns

406+ :: Query outer commons schemas params columns

407+ -> Query outer commons schemas params columns

408+ -> Query outer commons schemas params columns

325409q1 `intersectAll` q2 = UnsafeQuery $

326− parenthesized (renderQuery q1)

410+ parenthesized (renderSQL q1)

327411 <+> "INTERSECT" <+> "ALL"

328− <+> parenthesized (renderQuery q2)

412+ <+> parenthesized (renderSQL q2)

329413

330414-- | The results of two queries can be combined using the set operation

331415-- `except`, the set difference. Duplicate rows are eliminated.

332416except

333− :: Query schema params columns

334− -> Query schema params columns

335− -> Query schema params columns

417+ :: Query outer commons schemas params columns

418+ -> Query outer commons schemas params columns

419+ -> Query outer commons schemas params columns

336420q1 `except` q2 = UnsafeQuery $

337− parenthesized (renderQuery q1)

421+ parenthesized (renderSQL q1)

338422 <+> "EXCEPT"

339− <+> parenthesized (renderQuery q2)

423+ <+> parenthesized (renderSQL q2)

340424

341425-- | The results of two queries can be combined using the set operation

342426-- `exceptAll`, the set difference. Duplicate rows are retained.

343427exceptAll

344− :: Query schema params columns

345− -> Query schema params columns

346− -> Query schema params columns

428+ :: Query outer commons schemas params columns

429+ -> Query outer commons schemas params columns

430+ -> Query outer commons schemas params columns

347431q1 `exceptAll` q2 = UnsafeQuery $

348− parenthesized (renderQuery q1)

432+ parenthesized (renderSQL q1)

349433 <+> "EXCEPT" <+> "ALL"

350− <+> parenthesized (renderQuery q2)

434+ <+> parenthesized (renderSQL q2)

351435

352436{-----------------------------------------

353437SELECT queries

354438-----------------------------------------}

355439

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+

356525-- | the `TableExpression` in the `select` command constructs an intermediate

357526-- virtual table by possibly combining tables, views, eliminating rows,

358527-- grouping, etc. This table is finally passed on to processing by

359−-- the select list. The select list determines which columns of

528+-- the select list. The `Selection` determines which columns of

360529-- the intermediate table are actually output.

361530select

362− :: SListI columns

363− => NP (Aliased (Expression schema relations grouping params)) (column ': columns)

364− -- ^ select list

365− -> TableExpression schema params relations grouping

531+ :: (SListI row, row ~ (x ': xs))

532+ => Selection outer commons grp schemas params from row

533+ -- ^ selection

534+ -> TableExpression outer commons grp schemas params from

366535 -- ^ intermediate virtual table

367− -> Query schema params (column ': columns)

368−select list rels = UnsafeQuery $

536+ -> Query outer commons schemas params row

537+select selection tabexpr = UnsafeQuery $

369538 "SELECT"

370− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

371− <+> renderTableExpression rels

539+ <+> renderSQL selection

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

372552

373553-- | After the select list has been processed, the result table can

374554-- be subject to the elimination of duplicate rows using `selectDistinct`.

375555selectDistinct

376− :: SListI columns

377− => NP (Aliased (Expression schema relations 'Ungrouped params)) (column ': columns)

378− -- ^ select list

379− -> TableExpression schema params relations 'Ungrouped

556+ :: (SListI columns, columns ~ (col ': cols))

557+ => Selection outer commons grp schemas params from columns

558+ -- ^ selection

559+ -> TableExpression outer commons grp schemas params from

380560 -- ^ intermediate virtual table

381− -> Query schema params (column ': columns)

382−selectDistinct list rels = UnsafeQuery $

561+ -> Query outer commons schemas params columns

562+selectDistinct selection tabexpr = UnsafeQuery $

383563 "SELECT DISTINCT"

384− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

385− <+> renderTableExpression rels

386−

387−-- | The simplest kind of query is `selectStar` which emits all columns

388−-- that the table expression produces.

389−selectStar

390− :: HasUnique relation relations columns

391− => TableExpression schema params relations 'Ungrouped

392− -- ^ intermediate virtual table

393− -> Query schema params columns

394−selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels

395−

396−-- | A `selectDistinctStar` emits all columns that the table expression

397−-- produces and eliminates duplicate rows.

398−selectDistinctStar

399− :: HasUnique relation relations columns

400− => TableExpression schema params relations 'Ungrouped

564+ <+> renderSQL selection

565+ <+> renderSQL tabexpr

566+

567+-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead

568+-- of a general `Selection`.

569+selectDistinct_

570+ :: (SListI columns, columns ~ (col ': cols))

571+ => NP (Aliased (Expression outer commons grp schemas params from)) columns

572+ -- ^ select list

573+ -> TableExpression outer commons grp schemas params from

401574 -- ^ intermediate virtual table

402− -> Query schema params columns

403−selectDistinctStar rels = UnsafeQuery $

404− "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels

405−

406−-- | When working with multiple tables, it can also be useful to ask

407−-- for all the columns of a particular table, using `selectDotStar`.

408−selectDotStar

409− :: Has relation relations columns

410− => Alias relation

411− -- ^ particular virtual subtable

412− -> TableExpression schema params relations 'Ungrouped

575+ -> Query outer commons schemas params columns

576+selectDistinct_ = selectDistinct . List

577+

578+{-|

579+`selectDistinctOn` keeps only the first row of each set of rows where

580+the given expressions evaluate to equal. The DISTINCT ON expressions are

581+interpreted using the same rules as for ORDER BY. ORDER BY is used to

582+ensure that the desired row appears first.

583+

584+The DISTINCT ON expression(s) must match the leftmost ORDER BY expression(s).

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

413598 -- ^ intermediate virtual table

414− -> Query schema params columns

415−selectDotStar rel relations = UnsafeQuery $

416− "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression relations

417−

418−-- | A `selectDistinctDotStar` asks for all the columns of a particular table,

419−-- and eliminates duplicate rows.

420−selectDistinctDotStar

421− :: Has relation relations columns

422− => Alias relation

423− -- ^ particular virtual table

424− -> TableExpression schema params relations 'Ungrouped

599+ -> Query outer commons schemas params columns

600+selectDistinctOn distincts selection tab = UnsafeQuery $

601+ "SELECT DISTINCT ON"

602+ <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))

603+ <+> renderSQL selection

604+ <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})

605+ where

606+ renderDistinctOn = \case

607+ Asc expression -> renderSQL expression

608+ Desc expression -> renderSQL expression

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

425623 -- ^ intermediate virtual table

426− -> Query schema params columns

427−selectDistinctDotStar rel relations = UnsafeQuery $

428− "SELECT DISTINCT" <+> renderAlias rel <> ".*"

429− <+> renderTableExpression relations

624+ -> Query outer commons schemas params columns

625+selectDistinctOn_ distincts = selectDistinctOn distincts . List

430626

431627-- | `values` computes a row value or set of row values

432628-- specified by value expressions. It is most commonly used

@@ -434,16 +630,16 @@ selectDistinctDotStar rel relations = UnsafeQuery $

434630-- but it can be used on its own.

435631--

436632-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]

437−-- >>> let query = values (1 `As` #a :* "one" `As` #b :* Nil) [] :: Query '[] '[] Row

633+-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query outer commons schemas '[] Row

438634-- >>> printSQL query

439635-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")

440636values

441637 :: SListI cols

442− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

443− -> [NP (Aliased (Expression schema '[] 'Ungrouped params)) cols]

638+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

639+ -> [NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols]

444640 -- ^ When more than one row is specified, all the rows must

445641 -- must have the same number of elements

446− -> Query schema params cols

642+ -> Query outer commons schemas params cols

447643values rw rws = UnsafeQuery $ "SELECT * FROM"

448644 <+> parenthesized (

449645 "VALUES"

@@ -454,17 +650,17 @@ values rw rws = UnsafeQuery $ "SELECT * FROM"

454650 <+> parenthesized (renderCommaSeparated renderAliasPart rw)

455651 where

456652 renderAliasPart, renderValuePart

457− :: Aliased (Expression schema '[] 'Ungrouped params) ty -> ByteString

458− renderAliasPart (_ `As` name) = renderAlias name

459− renderValuePart (value `As` _) = renderExpression value

653+ :: Aliased (Expression outer commons 'Ungrouped schemas params '[] ) ty -> ByteString

654+ renderAliasPart (_ `As` name) = renderSQL name

655+ renderValuePart (value `As` _) = renderSQL value

460656

461657-- | `values_` computes a row value or set of row values

462658-- specified by value expressions.

463659values_

464660 :: SListI cols

465− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

661+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

466662 -- ^ one row of values

467− -> Query schema params cols

663+ -> Query outer commons schemas params cols

468664values_ rw = values rw []

469665

470666{-----------------------------------------

@@ -478,15 +674,17 @@ Table Expressions

478674-- to a table on disk, a so-called base table, but more complex expressions

479675-- can be used to modify or combine base tables in various ways.

480676data TableExpression

481− (schema :: SchemaType)

677+ (outer :: FromType)

678+ (commons :: FromType)

679+ (grp :: Grouping)

680+ (schemas :: SchemasType)

482681 (params :: [NullityType])

483− (relations :: RelationsType)

484− (grouping :: Grouping)

682+ (from :: FromType)

485683 = TableExpression

486− { fromClause :: FromClause schema params relations

684+ { fromClause :: FromClause outer commons schemas params from

487685 -- ^ A table reference that can be a table name, or a derived table such

488686 -- as a subquery, a @JOIN@ construct, or complex combinations of these.

489− , whereClause :: [Condition schema relations 'Ungrouped params]

687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]

490688 -- ^ optional search coditions, combined with `.&&`. After the processing

491689 -- of the `fromClause` is done, each row of the derived virtual table

492690 -- is checked against the search condition. If the result of the

@@ -495,20 +693,20 @@ data TableExpression

495693 -- at least one column of the table generated in the `fromClause`;

496694 -- this is not required, but otherwise the WHERE clause will

497695 -- be fairly useless.

498− , groupByClause :: GroupByClause relations grouping

696+ , groupByClause :: GroupByClause grp from

499697 -- ^ The `groupByClause` is used to group together those rows in a table

500698 -- that have the same values in all the columns listed. The order in which

501699 -- the columns are listed does not matter. The effect is to combine each

502700 -- set of rows having common values into one group row that represents all

503701 -- rows in the group. This is done to eliminate redundancy in the output

504702 -- and/or compute aggregates that apply to these groups.

505− , havingClause :: HavingClause schema relations grouping params

703+ , havingClause :: HavingClause outer commons grp schemas params from

506704 -- ^ If a table has been grouped using `groupBy`, but only certain groups

507705 -- are of interest, the `havingClause` can be used, much like a

508706 -- `whereClause`, to eliminate groups from the result. Expressions in the

509707 -- `havingClause` can refer both to grouped expressions and to ungrouped

510708 -- expressions (which necessarily involve an aggregate function).

511− , orderByClause :: [SortExpression schema relations grouping params]

709+ , orderByClause :: [SortExpression outer commons grp schemas params from]

512710 -- ^ The `orderByClause` is for optional sorting. When more than one

513711 -- `SortExpression` is specified, the later (right) values are used to sort

514712 -- rows that are equal according to the earlier (left) values.

@@ -518,72 +716,69 @@ data TableExpression

518716 -- will be returned (but possibly fewer, if the query itself yields

519717 -- fewer rows).

520718 , offsetClause :: [Word64]

521− -- ^ The `offsetClause` is combined with `+` to give an offset count

719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count

522720 -- if nonempty. The offset count says to skip that many rows before

523721 -- beginning to return rows. The rows are skipped before the limit count

524722 -- is applied.

525− }

723+ } deriving (GHC.Generic)

526724

527725-- | Render a `TableExpression`

528−renderTableExpression

529− :: TableExpression schema params relations grouping

530− -> ByteString

531−renderTableExpression

532− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

533− [ "FROM ", renderFromClause frm'

534− , renderWheres whs'

535− , renderGroupByClause grps'

536− , renderHavingClause hvs'

537− , renderOrderByClause srts'

538− , renderLimits lims'

539− , renderOffsets offs'

540− ]

541− where

542− renderWheres = \case

543− [] -> ""

544− wh:[] -> " WHERE" <+> renderExpression wh

545− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

546− renderOrderByClause = \case

547− [] -> ""

548− srts -> " ORDER BY"

549− <+> commaSeparated (renderSortExpression <$> srts)

550− renderLimits = \case

551− [] -> ""

552− lims -> " LIMIT" <+> fromString (show (minimum lims))

553− renderOffsets = \case

554− [] -> ""

555− offs -> " OFFSET" <+> fromString (show (sum offs))

726+instance RenderSQL (TableExpression outer commons grp schemas params from) where

727+ renderSQL

728+ (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

729+ [ "FROM ", renderSQL frm'

730+ , renderWheres whs'

731+ , renderSQL grps'

732+ , renderSQL hvs'

733+ , renderOrderByClause srts'

734+ , renderLimits lims'

735+ , renderOffsets offs' ]

736+ where

737+ renderWheres = \case

738+ [] -> ""

739+ wh:[] -> " WHERE" <+> renderSQL wh

740+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

741+ renderOrderByClause = \case

742+ [] -> ""

743+ srts -> " ORDER BY"

744+ <+> commaSeparated (renderSQL <$> srts)

745+ renderLimits = \case

746+ [] -> ""

747+ lims -> " LIMIT" <+> fromString (show (minimum lims))

748+ renderOffsets = \case

749+ [] -> ""

750+ offs -> " OFFSET" <+> fromString (show (sum offs))

556751

557752-- | A `from` generates a `TableExpression` from a table reference that can be

558753-- a table name, or a derived table such as a subquery, a JOIN construct,

559754-- or complex combinations of these. A `from` may be transformed by `where_`,

560−-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

561756-- to match the left-to-right sequencing of their placement in SQL.

562757from

563− :: FromClause schema params relations -- ^ table reference

564− -> TableExpression schema params relations 'Ungrouped

565−from rels = TableExpression rels [] NoGroups NoHaving [] [] []

758+ :: FromClause outer commons schemas params from -- ^ table reference

759+ -> TableExpression outer commons 'Ungrouped schemas params from

760+from tab = TableExpression tab [] noGroups NoHaving [] [] []

566761

567762-- | A `where_` is an endomorphism of `TableExpression`s which adds a

568763-- search condition to the `whereClause`.

569764where_

570− :: Condition schema relations 'Ungrouped params -- ^ filtering condition

571− -> TableExpression schema params relations grouping

572− -> TableExpression schema params relations grouping

765+ :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition

766+ -> TableExpression outer commons grp schemas params from

767+ -> TableExpression outer commons grp schemas params from

573768where_ wh rels = rels {whereClause = wh : whereClause rels}

574769

575−-- | A `group` is a transformation of `TableExpression`s which switches

576−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform

770+-- | A `groupBy` is a transformation of `TableExpression`s which switches

771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform

577772-- a "grand total" aggregation query.

578−group

773+groupBy

579774 :: SListI bys

580− => NP (By relations) bys -- ^ grouped columns

581− -> TableExpression schema params relations 'Ungrouped

582− -> TableExpression schema params relations ('Grouped bys)

583−group bys rels = TableExpression

775+ => NP (By from) bys -- ^ grouped columns

776+ -> TableExpression outer commons 'Ungrouped schemas params from

777+ -> TableExpression outer commons ('Grouped bys) schemas params from

778+groupBy bys rels = TableExpression

584779 { fromClause = fromClause rels

585780 , whereClause = whereClause rels

586− , groupByClause = Group bys

781+ , groupByClause = group bys

587782 , havingClause = Having []

588783 , orderByClause = []

589784 , limitClause = limitClause rels

@@ -593,34 +788,29 @@ group bys rels = TableExpression

593788-- | A `having` is an endomorphism of `TableExpression`s which adds a

594789-- search condition to the `havingClause`.

595790having

596− :: Condition schema relations ('Grouped bys) params -- ^ having condition

597− -> TableExpression schema params relations ('Grouped bys)

598− -> TableExpression schema params relations ('Grouped bys)

791+ :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition

792+ -> TableExpression outer commons ('Grouped bys) schemas params from

793+ -> TableExpression outer commons ('Grouped bys) schemas params from

599794having hv rels = rels

600795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

601796

602−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an

603−-- ordering to the right of the `orderByClause`.

604−orderBy

605− :: [SortExpression schema relations grouping params] -- ^ sort expressions

606− -> TableExpression schema params relations grouping

607− -> TableExpression schema params relations grouping

608−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

797+instance OrderBy TableExpression where

798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

609799

610800-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

611801-- `limitClause`.

612802limit

613803 :: Word64 -- ^ limit parameter

614− -> TableExpression schema params relations grouping

615− -> TableExpression schema params relations grouping

804+ -> TableExpression outer commons grp schemas params from

805+ -> TableExpression outer commons grp schemas params from

616806limit lim rels = rels {limitClause = lim : limitClause rels}

617807

618808-- | An `offset` is an endomorphism of `TableExpression`s which adds to the

619809-- `offsetClause`.

620810offset

621811 :: Word64 -- ^ offset parameter

622− -> TableExpression schema params relations grouping

623− -> TableExpression schema params relations grouping

812+ -> TableExpression outer commons grp schemas params from

813+ -> TableExpression outer commons grp schemas params from

624814offset off rels = rels {offsetClause = off : offsetClause rels}

625815

626816{-----------------------------------------

@@ -631,61 +821,76 @@ FROM clauses

631821A `FromClause` can be a table name, or a derived table such

632822as a subquery, a @JOIN@ construct, or complex combinations of these.

633823-}

634−newtype FromClause schema params relations

824+newtype FromClause outer commons schemas params from

635825 = UnsafeFromClause { renderFromClause :: ByteString }

636826 deriving (GHC.Generic,Show,Eq,Ord,NFData)

827+instance RenderSQL (FromClause outer commons schemas params from) where

828+ renderSQL = renderFromClause

637829

638−-- | A real `table` is a table from the schema.

830+-- | A real `table` is a table from the database.

639831table

640− :: Has tab schema ('Table table)

641− => Aliased Alias (alias ::: tab)

642− -> FromClause schema params '[alias ::: TableToRelation table]

832+ :: (Has sch schemas schema, Has tab schema ('Table table))

833+ => Aliased (QualifiedAlias sch) (alias ::: tab)

834+ -> FromClause outer commons schemas params '[alias ::: TableToRow table]

643835table (tab `As` alias) = UnsafeFromClause $

644− renderAlias tab <+> "AS" <+> renderAlias alias

836+ renderSQL tab <+> "AS" <+> renderSQL alias

645837

646838-- | `subquery` derives a table from a `Query`.

647839subquery

648− :: Aliased (Query schema params) rel

649− -> FromClause schema params '[rel]

650−subquery = UnsafeFromClause . renderAliasedAs (parenthesized . renderQuery)

840+ :: Aliased (Query outer commons schemas params) query

841+ -> FromClause outer commons schemas params '[query]

842+subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)

651843

652844-- | `view` derives a table from a `View`.

653845view

654− :: Has view schema ('View rel)

655− => Aliased Alias (alias ::: view)

656− -> FromClause schema params '[alias ::: rel]

846+ :: (Has sch schemas schema, Has vw schema ('View view))

847+ => Aliased (QualifiedAlias sch) (alias ::: vw)

848+ -> FromClause outer commons schemas params '[alias ::: view]

657849view (vw `As` alias) = UnsafeFromClause $

658− renderAlias vw <+> "AS" <+> renderAlias alias

850+ renderSQL vw <+> "AS" <+> renderSQL alias

851+

852+-- | `common` derives a table from a common table expression.

853+common

854+ :: Has cte commons common

855+ => Aliased Alias (alias ::: cte)

856+ -> FromClause outer commons schemas params '[alias ::: common]

857+common (cte `As` alias) = UnsafeFromClause $

858+ renderSQL cte <+> "AS" <+> renderSQL alias

859+

860+instance Additional (FromClause outer commons schemas params) where

861+ also right left = UnsafeFromClause $

862+ renderSQL left <> ", " <> renderSQL right

659863

660−{- | @left & crossJoin right@. For every possible combination of rows from

661− @left@ and @right@ (i.e., a Cartesian product), the joined table will contain

662− a row consisting of all columns in @left@ followed by all columns in @right@.

663− If the tables have @n@ and @m@ rows respectively, the joined table will

664− have @n * m@ rows.

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.

665870-}

666871crossJoin

667− :: FromClause schema params right

872+ :: FromClause outer commons schemas params right

668873 -- ^ right

669− -> FromClause schema params left

874+ -> FromClause outer commons schemas params left

670875 -- ^ left

671− -> FromClause schema params (Join left right)

876+ -> FromClause outer commons schemas params (Join left right)

672877crossJoin right left = UnsafeFromClause $

673− renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right

878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right

674879

675880{- | @left & innerJoin right on@. The joined table is filtered by

676881the @on@ condition.

677882-}

678883innerJoin

679− :: FromClause schema params right

884+ :: FromClause outer commons schemas params right

680885 -- ^ right

681− -> Condition schema (Join left right) 'Ungrouped params

886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

682887 -- ^ @on@ condition

683− -> FromClause schema params left

888+ -> FromClause outer commons schemas params left

684889 -- ^ left

685− -> FromClause schema params (Join left right)

890+ -> FromClause outer commons schemas params (Join left right)

686891innerJoin right on left = UnsafeFromClause $

687− renderFromClause left <+> "INNER JOIN" <+> renderFromClause right

688− <+> "ON" <+> renderExpression on

892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right

893+ <+> "ON" <+> renderSQL on

689894

690895{- | @left & leftOuterJoin right on@. First, an inner join is performed.

691896 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -693,16 +898,16 @@ innerJoin right on left = UnsafeFromClause $

693898 Thus, the joined table always has at least one row for each row in @left@.

694899-}

695900leftOuterJoin

696− :: FromClause schema params right

901+ :: FromClause outer commons schemas params right

697902 -- ^ right

698− -> Condition schema (Join left right) 'Ungrouped params

903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

699904 -- ^ @on@ condition

700− -> FromClause schema params left

905+ -> FromClause outer commons schemas params left

701906 -- ^ left

702− -> FromClause schema params (Join left (NullifyRelations right))

907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))

703908leftOuterJoin right on left = UnsafeFromClause $

704− renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right

705− <+> "ON" <+> renderExpression on

909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right

910+ <+> "ON" <+> renderSQL on

706911

707912{- | @left & rightOuterJoin right on@. First, an inner join is performed.

708913 Then, for each row in @right@ that does not satisfy the @on@ condition with

@@ -711,16 +916,16 @@ leftOuterJoin right on left = UnsafeFromClause $

711916 have a row for each row in @right@.

712917-}

713918rightOuterJoin

714− :: FromClause schema params right

919+ :: FromClause outer commons schemas params right

715920 -- ^ right

716− -> Condition schema (Join left right) 'Ungrouped params

921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

717922 -- ^ @on@ condition

718− -> FromClause schema params left

923+ -> FromClause outer commons schemas params left

719924 -- ^ left

720− -> FromClause schema params (Join (NullifyRelations left) right)

925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)

721926rightOuterJoin right on left = UnsafeFromClause $

722− renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right

723− <+> "ON" <+> renderExpression on

927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right

928+ <+> "ON" <+> renderSQL on

724929

725930{- | @left & fullOuterJoin right on@. First, an inner join is performed.

726931 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -730,47 +935,56 @@ rightOuterJoin right on left = UnsafeFromClause $

730935 is added.

731936-}

732937fullOuterJoin

733− :: FromClause schema params right

938+ :: FromClause outer commons schemas params right

734939 -- ^ right

735− -> Condition schema (Join left right) 'Ungrouped params

940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

736941 -- ^ @on@ condition

737− -> FromClause schema params left

942+ -> FromClause outer commons schemas params left

738943 -- ^ left

739− -> FromClause schema params

740− (Join (NullifyRelations left) (NullifyRelations right))

944+ -> FromClause outer commons schemas params

945+ (Join (NullifyFrom left) (NullifyFrom right))

741946fullOuterJoin right on left = UnsafeFromClause $

742− renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right

743− <+> "ON" <+> renderExpression on

947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right

948+ <+> "ON" <+> renderSQL on

744949

745950{-----------------------------------------

746951Grouping

747952-----------------------------------------}

748953

749−-- | `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

750955-- used to group together those rows in a table that have the same values

751956-- in all the columns listed. @By \#col@ will reference an unambiguous

752957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

753958-- qualified column @tab.col@.

754959data By

755− (relations :: RelationsType)

960+ (from :: FromType)

756961 (by :: (Symbol,Symbol)) where

757− By

758− :: (HasUnique relation relations columns, Has column columns ty)

962+ By1

963+ :: (HasUnique table from columns, Has column columns ty)

759964 => Alias column

760− -> By relations '(relation, column)

965+ -> By from '(table, column)

761966 By2

762− :: (Has relation relations columns, Has column columns ty)

763− => (Alias relation, Alias column)

764− -> By relations '(relation, column)

765−deriving instance Show (By relations by)

766−deriving instance Eq (By relations by)

767−deriving instance Ord (By relations by)

768−

769−-- | Renders a `By`.

770−renderBy :: By relations by -> ByteString

771−renderBy = \case

772− By column -> renderAlias column

773− By2 (rel, column) -> renderAlias rel <> "." <> renderAlias column

967+ :: (Has table from columns, Has column columns ty)

968+ => Alias table

969+ -> Alias column

970+ -> By from '(table, column)

971+deriving instance Show (By from by)

972+deriving instance Eq (By from by)

973+deriving instance Ord (By from by)

974+instance RenderSQL (By from by) where

975+ renderSQL = \case

976+ By1 column -> renderSQL column

977+ By2 rel column -> renderSQL rel <> "." <> renderSQL column

978+

979+instance (HasUnique rel rels cols, Has col cols ty, by ~ '(rel, col))

980+ => IsLabel col (By rels by) where fromLabel = By1 fromLabel

981+instance (HasUnique rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

982+ => IsLabel col (NP (By rels) bys) where fromLabel = By1 fromLabel :* Nil

983+instance (Has rel rels cols, Has col cols ty, by ~ '(rel, col))

984+ => IsQualified rel col (By rels by) where (!) = By2

985+instance (Has rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

986+ => IsQualified rel col (NP (By rels) bys) where

987+ rel ! col = By2 rel col :* Nil

774988

775989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

776990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

@@ -778,82 +992,107 @@ renderBy = \case

778992-- done on @NoGroups@ while all output `Expression`s must be aggregated

779993-- in @Group Nil@. In general, all output `Expression`s in the

780994-- complement of @bys@ must be aggregated in @Group bys@.

781−data GroupByClause relations grouping where

782− NoGroups :: GroupByClause relations 'Ungrouped

783− Group

784− :: SListI bys

785− => NP (By relations) bys

786− -> GroupByClause relations ('Grouped bys)

787−

788−-- | Renders a `GroupByClause`.

789−renderGroupByClause :: GroupByClause relations grouping -> ByteString

790−renderGroupByClause = \case

791− NoGroups -> ""

792− Group Nil -> ""

793− Group bys -> " GROUP BY" <+> renderCommaSeparated renderBy bys

995+newtype GroupByClause grp from = UnsafeGroupByClause

996+ { renderGroupByClause :: ByteString }

997+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

998+instance RenderSQL (GroupByClause grp from) where

999+ renderSQL = renderGroupByClause

1000+noGroups :: GroupByClause 'Ungrouped from

1001+noGroups = UnsafeGroupByClause ""

1002+group

1003+ :: SListI bys

1004+ => NP (By from) bys

1005+ -> GroupByClause ('Grouped bys) from

1006+group bys = UnsafeGroupByClause $ case bys of

1007+ Nil -> ""

1008+ bys' -> " GROUP BY" <+> renderCommaSeparated renderSQL bys'

7941009

7951010-- | A `HavingClause` is used to eliminate groups that are not of interest.

7961011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

7971012-- `TableExpression` must use `Having` whose conditions are combined with

7981013-- `.&&`.

799−data HavingClause schema relations grouping params where

800− NoHaving :: HavingClause schema relations 'Ungrouped params

1014+data HavingClause outer commons grp schemas params from where

1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from

8011016 Having

802− :: [Condition schema relations ('Grouped bys) params]

803− -> HavingClause schema relations ('Grouped bys) params

804−deriving instance Show (HavingClause schema relations grouping params)

805−deriving instance Eq (HavingClause schema relations grouping params)

806−deriving instance Ord (HavingClause schema relations grouping params)

1017+ :: [Condition outer commons ('Grouped bys) schemas params from]

1018+ -> HavingClause outer commons ('Grouped bys) schemas params from

1019+deriving instance Show (HavingClause outer commons grp schemas params from)

1020+deriving instance Eq (HavingClause outer commons grp schemas params from)

1021+deriving instance Ord (HavingClause outer commons grp schemas params from)

8071022

8081023-- | Render a `HavingClause`.

809−renderHavingClause :: HavingClause schema relations grouping params -> ByteString

810−renderHavingClause = \case

811− NoHaving -> ""

812− Having [] -> ""

813− Having conditions ->

814− " HAVING" <+> commaSeparated (renderExpression <$> conditions)

815−

816−{-----------------------------------------

817−Sorting

818−-----------------------------------------}

1024+instance RenderSQL (HavingClause outer commons grp schemas params from) where

1025+ renderSQL = \case

1026+ NoHaving -> ""

1027+ Having [] -> ""

1028+ Having conditions ->

1029+ " HAVING" <+> commaSeparated (renderSQL <$> conditions)

1030+

1031+-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.

1032+data CommonTableExpression statement

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

8191074

820−-- | `SortExpression`s are used by `sortBy` to optionally sort the results

821−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result

822−-- column to ascending or descending. Ascending order puts smaller values

823−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,

824−-- descending order is determined with the `.>` operator. `AscNullsFirst`,

825−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

826−-- determine whether nulls appear before or after non-null values in the sort

827−-- ordering of a `Null` result column.

828−data SortExpression schema relations grouping params where

829− Asc

830− :: Expression schema relations grouping params ('NotNull ty)

831− -> SortExpression schema relations grouping params

832− Desc

833− :: Expression schema relations grouping params ('NotNull ty)

834− -> SortExpression schema relations grouping params

835− AscNullsFirst

836− :: Expression schema relations grouping params ('Null ty)

837− -> SortExpression schema relations grouping params

838− AscNullsLast

839− :: Expression schema relations grouping params ('Null ty)

840− -> SortExpression schema relations grouping params

841− DescNullsFirst

842− :: Expression schema relations grouping params ('Null ty)

843− -> SortExpression schema relations grouping params

844− DescNullsLast

845− :: Expression schema relations grouping params ('Null ty)

846− -> SortExpression schema relations grouping params

847−deriving instance Show (SortExpression schema relations grouping params)

848−

849−-- | Render a `SortExpression`.

850−renderSortExpression :: SortExpression schema relations grouping params -> ByteString

851−renderSortExpression = \case

852− Asc expression -> renderExpression expression <+> "ASC"

853− Desc expression -> renderExpression expression <+> "DESC"

854− AscNullsFirst expression -> renderExpression expression

855− <+> "ASC NULLS FIRST"

856− DescNullsFirst expression -> renderExpression expression

857− <+> "DESC NULLS FIRST"

858− AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"

859− DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"

1075+{- |

1076+>>> import Data.Monoid (Sum (..))

1077+>>> import Data.Int (Int64)

1078+>>> :{

1079+ let

1080+ query :: Query_ schema () (Sum Int64)

1081+ query = withRecursive

1082+ ( values_ ((1 & astype int) `as` #n)

1083+ `unionAll`

1084+ select_ ((#n + 1) `as` #n)

1085+ (from (common #t) & where_ (#n .< 100)) `as` #t )

1086+ ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))

1087+ in printSQL query

1088+:}

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"

1090+-}

1091+withRecursive

1092+ :: Aliased (Query outer (recursive ': commons) schemas params) recursive

1093+ -> Query outer (recursive ': commons) schemas params row

1094+ -> Query outer commons schemas params row

1095+withRecursive (recursive `As` cte) query = UnsafeQuery $

1096+ "WITH RECURSIVE" <+> renderSQL cte

1097+ <+> "AS" <+> parenthesized (renderSQL recursive)

1098+ <+> renderSQL query

squeal-postgresql/src/Squeal/PostgreSQL/Render.hs+66−13

@@ -9,35 +9,48 @@ Rendering helper functions.

99-}

1010

1111{-# LANGUAGE

12− FlexibleContexts

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , FlexibleContexts

15+ , LambdaCase

1316 , MagicHash

1417 , OverloadedStrings

1518 , PolyKinds

1619 , RankNTypes

1720 , ScopedTypeVariables

21+ , TypeApplications

1822#-}

1923

2024module Squeal.PostgreSQL.Render

2125 ( -- * Render

22− parenthesized

26+ RenderSQL (..)

27+ , printSQL

28+ , escape

29+ , parenthesized

30+ , bracketed

2331 , (<+>)

2432 , commaSeparated

2533 , doubleQuoted

34+ , singleQuotedText

35+ , singleQuotedUtf8

2636 , renderCommaSeparated

37+ , renderCommaSeparatedConstraint

2738 , renderCommaSeparatedMaybe

2839 , renderNat

29− , RenderSQL (..)

30− , printSQL

40+ , renderSymbol

3141 ) where

3242

33−import Control.Monad.Base

43+import Control.Monad.IO.Class (MonadIO (..))

3444import Data.ByteString (ByteString)

35−import Data.Maybe

45+import Data.Maybe (catMaybes)

3646import Data.Monoid ((<>))

47+import Data.Text (Text)

3748import Generics.SOP

3849import GHC.Exts

39−import GHC.TypeLits

50+import GHC.TypeLits hiding (Text)

4051

52+import qualified Data.Text as Text

53+import qualified Data.Text.Encoding as Text

4154import qualified Data.ByteString as ByteString

4255import qualified Data.ByteString.Char8 as Char8

4356

@@ -45,8 +58,13 @@ import qualified Data.ByteString.Char8 as Char8

4558parenthesized :: ByteString -> ByteString

4659parenthesized str = "(" <> str <> ")"

4760

61+-- | Square bracket a `ByteString`

62+bracketed :: ByteString -> ByteString

63+bracketed str = "[" <> str <> "]"

64+

4865-- | Concatenate two `ByteString`s with a space between.

4966(<+>) :: ByteString -> ByteString -> ByteString

67+infixr 7 <+>

5068str1 <+> str2 = str1 <> " " <> str2

5169

5270-- | Comma separate a list of `ByteString`s.

@@ -57,6 +75,15 @@ commaSeparated = ByteString.intercalate ", "

5775doubleQuoted :: ByteString -> ByteString

5876doubleQuoted str = "\"" <> str <> "\""

5977

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+

6087-- | Comma separate the renderings of a heterogeneous list.

6188renderCommaSeparated

6289 :: SListI xs

@@ -67,6 +94,16 @@ renderCommaSeparated render

6794 . hcollapse

6895 . hmap (K . render)

6996

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+

70107-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

71108-- `Nothing`s.

72109renderCommaSeparatedMaybe

@@ -80,13 +117,29 @@ renderCommaSeparatedMaybe render

80117 . hmap (K . render)

81118

82119-- | Render a promoted `Nat`.

83−renderNat :: KnownNat n => proxy n -> ByteString

84−renderNat (_ :: proxy n) = fromString (show (natVal' (proxy# :: Proxy# n)))

120+renderNat :: forall n. KnownNat n => ByteString

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))

85126

86127-- | A class for rendering SQL

87−class RenderSQL sql where

88− renderSQL :: sql -> ByteString

128+class RenderSQL sql where renderSQL :: sql -> ByteString

89129

90130-- | Print SQL.

91−printSQL :: (RenderSQL sql, MonadBase IO io) => sql -> io ()

92−printSQL = liftBase . Char8.putStrLn . renderSQL

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+318−561

@@ -1,16 +1,15 @@

11{-|

22Module: Squeal.PostgreSQL.Schema

33Description: Embedding of PostgreSQL type and alias system

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

55Maintainer: eitan@morphism.tech

66Stability: experimental

8−This module provides a type-level DSL for kinds of Postgres types,

8+`Squeal.PostgreSQL.Schema` provides a type-level DSL for kinds of Postgres types,

99tables, schema, constraints, aliases, enumerated labels, and groupings.

1010It also defines useful type families to operate on these. Finally,

1111it defines an embedding of Haskell types into Postgres types.

1212-}

13−

1413{-# LANGUAGE

1514 AllowAmbiguousTypes

1615 , ConstraintKinds

@@ -20,7 +19,9 @@ it defines an embedding of Haskell types into Postgres types.

2019 , FlexibleInstances

2120 , FunctionalDependencies

2221 , GADTs

22+ , LambdaCase

2323 , OverloadedStrings

24+ , QuantifiedConstraints

2425 , RankNTypes

2526 , ScopedTypeVariables

2627 , StandaloneDeriving

@@ -33,122 +34,85 @@ it defines an embedding of Haskell types into Postgres types.

3334#-}

3435

3536module Squeal.PostgreSQL.Schema

36− ( -- * Types

37+ ( -- * Postgres Types

3738 PGType (..)

38− , HasOid (..)

3939 , NullityType (..)

40+ , RowType

41+ , FromType

42+ -- * Schema Types

4043 , ColumnType

41− -- * Tables

4244 , ColumnsType

43− , RelationType

44− , NilRelation

45− , RelationsType

4645 , TableType

47− -- * Schema

4846 , SchemumType (..)

47+ , IndexType (..)

48+ , FunctionType

49+ , OperatorType (..)

50+ , ReturnsType (..)

4951 , SchemaType

52+ , SchemasType

53+ , Public

5054 -- * Constraints

5155 , (:=>)

5256 , ColumnConstraint (..)

5357 , TableConstraint (..)

5458 , TableConstraints

55− , NilTableConstraints

5659 , Uniquely

57− -- * Aliases

58− , (:::)

59− , Alias (Alias)

60− , renderAlias

61− , renderAliases

62− , Aliased (As)

63− , renderAliasedAs

64− , AliasesOf

65− , ZipAliased (..)

66− , Has

67− , HasUnique

68− , HasAll

69− , IsLabel (..)

70− , IsQualified (..)

7160 -- * Enumerated Labels

7261 , IsPGlabel (..)

7362 , PGlabel (..)

74− , renderLabel

75− , renderLabels

76− -- * Grouping

77− , Grouping (..)

78− , GroupedBy

79− -- * Type Families

80− , Join

81− , With

63+ -- * Data Definitions

8264 , Create

65+ , CreateIfNotExists

66+ , CreateOrReplace

8367 , Drop

68+ , DropSchemum

69+ , DropIfExists

70+ , DropSchemumIfExists

8471 , Alter

72+ , AlterIfExists

8573 , Rename

86− , Elem

87− , In

74+ , RenameIfExists

75+ , ConstraintInvolves

76+ , DropIfConstraintsInvolve

77+ , IsNotElem

78+ , AllUnique

79+ -- * Type Classifications

8880 , PGNum

8981 , PGIntegral

9082 , PGFloating

9183 , PGTypeOf

92− , SameTypes

84+ , PGJsonType

85+ , PGJsonKey

9386 , SamePGType

9487 , AllNotNull

9588 , NotAllNull

89+ -- * Nullifications

9690 , NullifyType

97− , NullifyRelation

98− , NullifyRelations

99− , ColumnsToRelation

91+ , NullifyRow

92+ , NullifyFrom

93+ -- * Table Conversions

10094 , TableToColumns

101− , TableToRelation

102− , ConstraintInvolves

103− , DropIfConstraintsInvolve

104− -- * Embedding

105− , PG

106− , EnumFrom

107− , LabelsFrom

108− , CompositeFrom

109− , FieldNamesFrom

110− , FieldTypesFrom

111− , ConstructorsOf

112− , ConstructorNameOf

113− , ConstructorNamesOf

114− , FieldsOf

115− , FieldNameOf

116− , FieldNamesOf

117− , FieldTypeOf

118− , FieldTypesOf

119− , RecordCodeOf

120− , MapMaybes (..)

121− , Nulls

95+ , ColumnsToRow

96+ , TableToRow

12297 ) where

12398

124−import Control.DeepSeq

125−import Data.Aeson (Value)

126−import Data.ByteString (ByteString)

127−import Data.Int (Int16, Int32, Int64)

99+import Control.Category

128100import Data.Kind

129101import Data.Monoid hiding (All)

130−import Data.Scientific (Scientific)

131−import Data.String

132−import Data.Text (Text)

133−import Data.Time

134−import Data.Word (Word16, Word32, Word64)

135102import Data.Type.Bool

136−import Data.UUID.Types (UUID)

137103import Generics.SOP

138−import GHC.OverloadedLabels

139104import GHC.TypeLits

140−import Network.IP.Addr

141−

142−import qualified Data.ByteString.Lazy as Lazy

143−import qualified Data.Text.Lazy as Lazy

144−import qualified GHC.Generics as GHC

145−import qualified Generics.SOP.Type.Metadata as Type

105+import Prelude hiding (id, (.))

146106

107+import Squeal.PostgreSQL.Alias

108+import Squeal.PostgreSQL.List

147109import Squeal.PostgreSQL.Render

148110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

149114-- | `PGType` is the promoted datakind of PostgreSQL types.

150115--

151−-- >>> import Squeal.PostgreSQL.Schema

152116-- >>> :kind 'PGbool

153117-- 'PGbool :: PGType

154118data PGType

@@ -159,6 +123,7 @@ data PGType

159123 | PGnumeric -- ^ arbitrary precision numeric type

160124 | PGfloat4 -- ^ single precision floating-point number (4 bytes)

161125 | PGfloat8 -- ^ double precision floating-point number (8 bytes)

126+ | PGmoney -- ^ currency amount

162127 | PGchar Nat -- ^ fixed-length character string

163128 | PGvarchar Nat -- ^ variable-length character string

164129 | PGtext -- ^ variable-length character string

@@ -173,40 +138,16 @@ data PGType

173138 | PGinet -- ^ IPv4 or IPv6 host address

174139 | PGjson -- ^ textual JSON data

175140 | PGjsonb -- ^ binary JSON data, decomposed

176− | PGvararray PGType -- ^ variable length array

177− | PGfixarray Nat PGType -- ^ fixed length array

178− | PGenum [Symbol]

179− | PGcomposite [(Symbol, PGType)]

141+ | PGvararray NullityType -- ^ variable 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).

180149 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types

181150

182−-- | The object identifier of a `PGType`.

183−--

184−-- >>> :set -XTypeApplications

185−-- >>> oid @'PGbool

186−-- 16

187−class HasOid (ty :: PGType) where oid :: Word32

188−instance HasOid 'PGbool where oid = 16

189−instance HasOid 'PGint2 where oid = 21

190−instance HasOid 'PGint4 where oid = 23

191−instance HasOid 'PGint8 where oid = 20

192−instance HasOid 'PGnumeric where oid = 1700

193−instance HasOid 'PGfloat4 where oid = 700

194−instance HasOid 'PGfloat8 where oid = 701

195−instance HasOid ('PGchar n) where oid = 18

196−instance HasOid ('PGvarchar n) where oid = 1043

197−instance HasOid 'PGtext where oid = 25

198−instance HasOid 'PGbytea where oid = 17

199−instance HasOid 'PGtimestamp where oid = 1114

200−instance HasOid 'PGtimestamptz where oid = 1184

201−instance HasOid 'PGdate where oid = 1082

202−instance HasOid 'PGtime where oid = 1083

203−instance HasOid 'PGtimetz where oid = 1266

204−instance HasOid 'PGinterval where oid = 1186

205−instance HasOid 'PGuuid where oid = 2950

206−instance HasOid 'PGinet where oid = 869

207−instance HasOid 'PGjson where oid = 114

208−instance HasOid 'PGjsonb where oid = 3802

209−

210151-- | `NullityType` encodes the potential presence or definite absence of a

211152-- @NULL@ allowing operations which are sensitive to such to be well typed.

212153--

@@ -225,11 +166,6 @@ data NullityType

225166type (:=>) constraint ty = '(constraint,ty)

226167infixr 7 :=>

227168

228−-- | The alias operator `:::` is like a promoted version of `As`,

229−-- a type level pair between an alias and some type.

230−type (:::) (alias :: Symbol) ty = '(alias,ty)

231−infixr 6 :::

232−

233169-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.

234170-- A column can be assigned a default value.

235171-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also

@@ -271,11 +207,14 @@ data TableConstraint

271207 | PrimaryKey [Symbol]

272208 | ForeignKey [Symbol] Symbol [Symbol]

273209

274−-- | 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+-}

275217type TableConstraints = [(Symbol,TableConstraint)]

276−-- | A monokinded empty `TableConstraints`.

277−type family NilTableConstraints :: TableConstraints where

278− NilTableConstraints = '[]

279218

280219-- | A `ForeignKey` must reference columns that either are

281220-- a `PrimaryKey` or form a `Unique` constraint.

@@ -299,225 +238,64 @@ type family Uniquely

299238-- :}

300239type TableType = (TableConstraints,ColumnsType)

301240

302−-- | `RelationType` is a row of `NullityType`

303−--

304−-- >>> :{

305−-- type family PersonRelation :: RelationType where

306−-- PersonRelation =

307−-- '[ "name" ::: 'NotNull 'PGtext

308−-- , "age" ::: 'NotNull 'PGint4

309−-- , "dateOfBirth" ::: 'Null 'PGdate

310−-- ]

311−-- :}

312−type RelationType = [(Symbol,NullityType)]

313−-- | A monokinded empty `RelationType`.

314−type family NilRelation :: RelationType where NilRelation = '[]

315−

316−-- | `RelationsType` is a row of `RelationType`s, thought of as a product.

317−type RelationsType = [(Symbol,RelationType)]

241+{- | A `RowType` is a row of `NullityType`. They correspond to Haskell

242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.

243+

244+>>> :{

245+type family PersonRow :: RowType where

246+ PersonRow =

247+ '[ "name" ::: 'NotNull 'PGtext

248+ , "age" ::: 'NotNull 'PGint4

249+ , "dateOfBirth" ::: 'Null 'PGdate

250+ ]

251+:}

252+-}

253+type RowType = [(Symbol,NullityType)]

318254

319−-- | `ColumnsToRelation` removes column constraints.

320−type family ColumnsToRelation (columns :: ColumnsType) :: RelationType where

321− ColumnsToRelation '[] = '[]

322− ColumnsToRelation (column ::: constraint :=> ty ': columns) =

323− column ::: ty ': ColumnsToRelation columns

255+{- | `FromType` is a row of `RowType`s. It can be thought of as

256+a product, or horizontal gluing and is used in `Squeal.PostgreSQL.Query.FromClause`s

257+and `Squeal.PostgreSQL.Query.TableExpression`s.

258+-}

259+type FromType = [(Symbol,RowType)]

260+

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 '[] = '[]

324276

325277-- | `TableToColumns` removes table constraints.

326278type family TableToColumns (table :: TableType) :: ColumnsType where

327279 TableToColumns (constraints :=> columns) = columns

328280

329−-- | Convert a table to a relation.

330−type family TableToRelation (table :: TableType) :: RelationType where

331− TableToRelation tab = ColumnsToRelation (TableToColumns tab)

281+-- | Convert a table to a row type.

282+type family TableToRow (table :: TableType) :: RowType where

283+ TableToRow tab = ColumnsToRow (TableToColumns tab)

332284

333−-- | `Grouping` is an auxiliary namespace, created by

334−-- @GROUP BY@ clauses (`Squeal.PostgreSQL.Query.group`), and used

335−-- for typesafe aggregation

336−data Grouping

337− = Ungrouped -- ^ no aggregation permitted

338− | Grouped [(Symbol,Symbol)] -- ^ aggregation required for any column which is not grouped

285+-- | Numeric Postgres types.

286+type PGNum =

287+ '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

339288

340−{- | A `GroupedBy` constraint indicates that a table qualified column is

341−a member of the auxiliary namespace created by @GROUP BY@ clauses and thus,

342−may be called in an output `Squeal.PostgreSQL.Expression.Expression` without aggregating.

343−-}

344−class (KnownSymbol relation, KnownSymbol column)

345− => GroupedBy relation column bys where

346−instance {-# OVERLAPPING #-} (KnownSymbol relation, KnownSymbol column)

347− => GroupedBy relation column ('(table,column) ': bys)

348−instance {-# OVERLAPPABLE #-}

349− ( KnownSymbol relation

350− , KnownSymbol column

351− , GroupedBy relation column bys

352− ) => GroupedBy relation column (tabcol ': bys)

353−

354−-- | `Alias`es are proxies for a type level string or `Symbol`

355−-- and have an `IsLabel` instance so that with @-XOverloadedLabels@

356−--

357−-- >>> :set -XOverloadedLabels

358−-- >>> #foobar :: Alias "foobar"

359−-- Alias

360−data Alias (alias :: Symbol) = Alias

361− deriving (Eq,GHC.Generic,Ord,Show,NFData)

362−instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where

363− fromLabel = Alias

364−instance aliases ~ '[alias] => IsLabel alias (NP Alias aliases) where

365− fromLabel = fromLabel :* Nil

366−instance KnownSymbol alias => RenderSQL (Alias alias) where renderSQL = renderAlias

367−

368−-- | >>> renderAlias #jimbob

369−-- "\"jimbob\""

370−renderAlias :: KnownSymbol alias => Alias alias -> ByteString

371−renderAlias = doubleQuoted . fromString . symbolVal

372−

373−-- | >>> import Generics.SOP (NP(..))

374−-- >>> renderAliases (#jimbob :* #kandi :* Nil)

375−-- ["\"jimbob\"","\"kandi\""]

376−renderAliases

377− :: All KnownSymbol aliases => NP Alias aliases -> [ByteString]

378−renderAliases = hcollapse

379− . hcmap (Proxy @KnownSymbol) (K . renderAlias)

380−

381−-- | The `As` operator is used to name an expression. `As` is like a demoted

382−-- version of `:::`.

383−--

384−-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)

385−-- As (Just "hello") Alias

386−data Aliased expression aliased where

387− As

388− :: KnownSymbol alias

389− => expression ty

390− -> Alias alias

391− -> Aliased expression (alias ::: ty)

392−deriving instance Show (expression ty)

393− => Show (Aliased expression (alias ::: ty))

394−deriving instance Eq (expression ty)

395− => Eq (Aliased expression (alias ::: ty))

396−deriving instance Ord (expression ty)

397− => Ord (Aliased expression (alias ::: ty))

398−instance (alias0 ~ alias1, alias0 ~ alias2, KnownSymbol alias2)

399− => IsLabel alias0 (Aliased Alias (alias1 ::: alias2)) where

400− fromLabel = fromLabel @alias2 `As` fromLabel @alias1

401−

402−-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")

403−-- >>> renderAliasedAs renderMaybe (Just (3::Int) `As` #an_int)

404−-- "Just AS \"an_int\""

405−renderAliasedAs

406− :: (forall ty. expression ty -> ByteString)

407− -> Aliased expression aliased

408− -> ByteString

409−renderAliasedAs render (expression `As` alias) =

410− render expression <> " AS " <> renderAlias alias

411−

412−-- | `AliasesOf` retains the AliasesOf in a row.

413−type family AliasesOf aliaseds where

414− AliasesOf '[] = '[]

415− AliasesOf (alias ::: ty ': tys) = alias ': AliasesOf tys

416−

417−-- | The `ZipAliased` class provides a type family for zipping

418−-- `Symbol` lists together with arbitrary lists of the same size,

419−-- with an associated type family `ZipAs`, together with

420−-- a method `zipAs` for zipping heterogeneous lists of `Alias`es

421−-- together with a heterogeneous list of expressions into

422−-- a heterogeneous list of `Aliased` expressions.

423−class

424− ( SListI (ZipAs ns xs)

425− , All KnownSymbol ns

426− ) => ZipAliased ns xs where

427−

428− type family ZipAs

429− (ns :: [Symbol]) (xs :: [k]) = (zs :: [(Symbol,k)]) | zs -> ns xs

430−

431− zipAs

432− :: NP Alias ns

433− -> NP expr xs

434− -> NP (Aliased expr) (ZipAs ns xs)

435−

436−instance ZipAliased '[] '[] where

437− type ZipAs '[] '[] = '[]

438− zipAs Nil Nil = Nil

439−

440−instance

441− ( KnownSymbol n

442− , ZipAliased ns xs

443− ) => ZipAliased (n ': ns) (x ': xs) where

444− type ZipAs (n ': ns) (x ': xs) = '(n,x) ': ZipAs ns xs

445− zipAs (n :* ns) (x :* xs) = x `As` n :* zipAs ns xs

446−

447−-- | @HasUnique alias fields field@ is a constraint that proves that

448−-- @fields@ is a singleton of @alias ::: field@.

449−type HasUnique alias fields field = fields ~ '[alias ::: field]

450−

451−-- | @Has alias fields field@ is a constraint that proves that

452−-- @fields@ has a field of @alias ::: field@, inferring @field@

453−-- from @alias@ and @fields@.

454−class KnownSymbol alias =>

455− Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)

456− | alias fields -> field where

457−instance {-# OVERLAPPING #-} KnownSymbol alias

458− => Has alias (alias ::: field ': fields) field

459−instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)

460− => Has alias (field' ': fields) field

461−

462−-- | `HasAll` extends `Has` to take lists of @aliases@ and @fields@ and infer

463−-- a list of @subfields@.

464−class

465− ( All KnownSymbol aliases

466− ) => HasAll

467− (aliases :: [Symbol])

468− (fields :: [(Symbol,kind)])

469− (subfields :: [(Symbol,kind)])

470− | aliases fields -> subfields where

471−instance {-# OVERLAPPING #-} HasAll '[] fields '[]

472−instance {-# OVERLAPPABLE #-}

473− (Has alias fields field, HasAll aliases fields subfields)

474− => HasAll (alias ': aliases) fields (alias ::: field ': subfields)

475−

476−-- | Analagous to `IsLabel`, the constraint

477−-- `IsQualified` defines `!` for a column alias qualified

478−-- by a table alias.

479−class IsQualified table column expression where

480− (!) :: Alias table -> Alias column -> expression

481− infixl 9 !

482−instance IsQualified table column (Alias table, Alias column) where (!) = (,)

483−

484−-- | @Elem@ is a promoted `Data.List.elem`.

485−type family Elem x xs where

486− Elem x '[] = 'False

487− Elem x (x ': xs) = 'True

488− Elem x (_ ': xs) = Elem x xs

489−

490−-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.

491−type family In x xs :: Constraint where In x xs = Elem x xs ~ 'True

492−

493−-- | `PGNum` is a constraint on `PGType` whose

494−-- `Squeal.PostgreSQL.Expression.Expression`s have a `Num` constraint.

495−type PGNum ty =

496− In ty '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

497−

498−-- | `PGFloating` is a constraint on `PGType` whose

499−-- `Squeal.PostgreSQL.Expression.Expression`s

500−-- have `Fractional` and `Floating` constraints.

501−type PGFloating ty = In ty '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

502−

503−-- | `PGIntegral` is a constraint on `PGType` whose

504−-- `Squeal.PostgreSQL.Expression.Expression`s

505−-- have `Squeal.PostgreSQL.Expression.div_` and

506−-- `Squeal.PostgreSQL.Expression.mod_` functions.

507−type PGIntegral ty = In ty '[ 'PGint2, 'PGint4, 'PGint8]

289+-- | Floating Postgres types.

290+type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

291+

292+-- | Integral Postgres types.

293+type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]

508294

509295-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

510296type family PGTypeOf (ty :: NullityType) :: PGType where

511297 PGTypeOf (nullity pg) = pg

512298

513−-- | `SameTypes` is a constraint that proves two `ColumnsType`s have the same

514−-- length and the same `ColumnType`s.

515−type family SameTypes (columns0 :: ColumnsType) (columns1 :: ColumnsType)

516− :: Constraint where

517− SameTypes '[] '[] = ()

518− SameTypes (column0 ::: def0 :=> ty0 ': columns0) (column1 ::: def1 :=> ty1 ': columns1)

519− = (ty0 ~ ty1, SameTypes columns0 columns1)

520−

521299-- | Equality constraint on the underlying `PGType` of two columns.

522300class SamePGType

523301 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where

@@ -527,39 +305,63 @@ instance ty0 ~ ty1 => SamePGType

527305

528306-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.

529307type 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

530314 AllNotNull '[] = ()

531− AllNotNull (column ::: def :=> 'NotNull ty ': columns) = AllNotNull columns

532315

533316-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

534317-- @NOT NULL@.

535318type family NotAllNull (columns :: ColumnsType) :: Constraint where

536− NotAllNull (column ::: def :=> 'NotNull ty ': columns) = ()

537− NotAllNull (column ::: def :=> 'Null ty ': columns) = NotAllNull columns

538−

539−-- | `NullifyType` is an idempotent that nullifies a `ColumnType`.

319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

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`.

540328type family NullifyType (ty :: NullityType) :: NullityType where

541329 NullifyType ('Null ty) = 'Null ty

542330 NullifyType ('NotNull ty) = 'Null ty

543331

544−-- | `NullifyRelation` is an idempotent that nullifies a `ColumnsType`.

545−type family NullifyRelation (columns :: RelationType) :: RelationType where

546− NullifyRelation '[] = '[]

547− NullifyRelation (column ::: ty ': columns) =

548− column ::: NullifyType ty ': NullifyRelation columns

549−

550−-- | `NullifyRelations` is an idempotent that nullifies a `RelationsType`

332+-- | `NullifyRow` is an idempotent that nullifies a `RowType`.

333+type family NullifyRow (columns :: RowType) :: RowType where

334+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': columns) =

335+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': column5 ::: NullifyType ty5 ': NullifyRow columns

336+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': columns) =

337+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': NullifyRow columns

338+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': columns) =

339+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': NullifyRow columns

340+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': columns) =

341+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': NullifyRow columns

342+ NullifyRow (column ::: ty ': column1 ::: ty1 ': columns) =

343+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': NullifyRow columns

344+ NullifyRow (column ::: ty ': columns) =

345+ column ::: NullifyType ty ': NullifyRow columns

346+ NullifyRow '[] = '[]

347+

348+-- | `NullifyFrom` is an idempotent that nullifies a `FromType`

551349-- used to nullify the left or right hand side of an outer join

552350-- in a `Squeal.PostgreSQL.Query.FromClause`.

553−type family NullifyRelations (tables :: RelationsType) :: RelationsType where

554− NullifyRelations '[] = '[]

555− NullifyRelations (table ::: columns ': tables) =

556− table ::: NullifyRelation columns ': NullifyRelations tables

557−

558−-- | `Join` is simply promoted `++` and is used in @JOIN@s in

559−-- `Squeal.PostgreSQL.Query.FromClause`s.

560−type family Join xs ys where

561− Join '[] ys = ys

562− Join (x ': xs) ys = x ': Join xs ys

351+type family NullifyFrom (tables :: FromType) :: FromType where

352+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': table5 ::: columns5 ': tables) =

353+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns5 ': table5 ::: NullifyRow columns4 ': NullifyFrom tables

354+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': tables) =

355+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns4 ': NullifyFrom tables

356+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': tables) =

357+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': NullifyFrom tables

358+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': tables) =

359+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': NullifyFrom tables

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 '[] = '[]

563365

564366-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in

565367-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

@@ -569,62 +371,100 @@ type family Create alias x xs where

569371 Create alias x (alias ::: y ': xs) = TypeError

570372 ('Text "Create: alias "

571373 ':<>: 'ShowType alias

572− ':<>: 'Text "already in use")

374+ ':<>: 'Text "already exists")

573375 Create alias y (x ': xs) = x ': Create alias y xs

574376

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+

575394-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

576395-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

577396-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

578397type family Drop alias xs where

579− 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

580403 Drop alias (x ': xs) = x ': Drop alias xs

581404

405+type family DropSchemum alias sch xs where

406+ DropSchemum alias sch '[] = TypeError

407+ ('Text "DropSchemum: alias "

408+ ':<>: 'ShowType alias

409+ ':<>: 'Text " does not exist" )

410+ DropSchemum alias sch (alias ::: sch x ': xs) = xs

411+ DropSchemum alias sch0 (alias ::: sch1 x ': xs) = TypeError

412+ ('Text "DropSchemum: expected schemum "

413+ ':<>: 'ShowType sch0

414+ ':<>: 'Text " but alias "

415+ ':<>: 'ShowType alias

416+ ':<>: 'Text " has schemum "

417+ ':<>: 'ShowType sch1)

418+ DropSchemum alias sch (x ': xs) = x ': DropSchemum alias sch xs

419+

420+type family DropIfExists alias xs where

421+ DropIfExists alias '[] = '[]

422+ DropIfExists alias (alias ::: x ': xs) = xs

423+ DropIfExists alias (x ': xs) = x ': DropIfExists alias xs

424+

425+type family DropSchemumIfExists alias sch xs where

426+ DropSchemumIfExists alias sch '[] = '[]

427+ DropSchemumIfExists alias sch (alias ::: sch x ': xs) = xs

428+ DropSchemumIfExists alias sch0 (alias ::: sch1 x ': xs) = TypeError

429+ ('Text "DropSchemumIfExists: expected schemum "

430+ ':<>: 'ShowType sch1

431+ ':<>: 'Text " but alias "

432+ ':<>: 'ShowType alias

433+ ':<>: 'Text " has schemum "

434+ ':<>: 'ShowType sch0)

435+ DropSchemumIfExists alias sch (x ': xs) = x ': DropSchemumIfExists alias sch xs

436+

582437-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@

583−-- with the type `x` and is used in `Squeal.PostgreSQL.Definition.alterTable`

438+-- with the type @x@ and is used in `Squeal.PostgreSQL.Definition.alterTable`

584439-- and `Squeal.PostgreSQL.Definition.alterColumn`.

585440type family Alter alias x xs where

441+ Alter alias x '[] = TypeError

442+ ('Text "Alter: alias "

443+ ':<>: 'ShowType alias

444+ ':<>: 'Text " does not exist" )

586445 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

587446 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

588447

589−-- type family AddConstraint constraint ty where

590−-- AddConstraint constraint (constraints :=> ty)

591−-- = AsSet (constraint ': constraints) :=> ty

592−

593−-- type family DeleteFromList (e :: elem) (list :: [elem]) where

594−-- DeleteFromList elem '[] = '[]

595−-- DeleteFromList elem (x ': xs) =

596−-- If (Cmp elem x == 'EQ) xs (x ': DeleteFromList elem xs)

597−

598−-- type family DropConstraint constraint ty where

599−-- DropConstraint constraint (constraints :=> ty)

600−-- = (AsSet (DeleteFromList constraint constraints)) :=> ty

448+type family AlterIfExists alias x xs where

449+ AlterIfExists alias x '[] = '[]

450+ AlterIfExists alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

451+ AlterIfExists alias x1 (x0 ': xs) = x0 ': AlterIfExists alias x1 xs

601452

602453-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@

603454-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

604455-- `Squeal.PostgreSQL.Definition.renameColumn`.

605456type family Rename alias0 alias1 xs where

457+ Rename alias0 alias1 '[] = TypeError

458+ ('Text "Rename: alias "

459+ ':<>: 'ShowType alias0

460+ ':<>: 'Text " does not exist" )

606461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

607462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

608463

609−-- | `MapMaybes` is used in the binary instances of composite types.

610−class MapMaybes xs where

611− type family Maybes (xs :: [Type]) = (mxs :: [Type]) | mxs -> xs

612− maybes :: NP Maybe xs -> NP I (Maybes xs)

613− unMaybes :: NP I (Maybes xs) -> NP Maybe xs

614−instance MapMaybes '[] where

615− type Maybes '[] = '[]

616− maybes Nil = Nil

617− unMaybes Nil = Nil

618−instance MapMaybes xs => MapMaybes (x ': xs) where

619− type Maybes (x ': xs) = Maybe x ': Maybes xs

620− maybes (x :* xs) = I x :* maybes xs

621− unMaybes (I mx :* xs) = mx :* unMaybes xs

622−

623−-- | `Nulls` is used to construct a `Squeal.Postgresql.Expression.row`

624−-- of a composite type.

625−type family Nulls tys where

626− Nulls '[] = '[]

627− Nulls (field ::: ty ': tys) = field ::: 'Null ty ': Nulls tys

464+type family RenameIfExists alias0 alias1 xs where

465+ RenameIfExists alias x '[] = '[]

466+ RenameIfExists alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

467+ RenameIfExists alias0 alias1 (x ': xs) = x ': RenameIfExists alias0 alias1 xs

628468

629469-- | Check if a `TableConstraint` involves a column

630470type family ConstraintInvolves column constraint where

@@ -646,194 +486,111 @@ type family DropIfConstraintsInvolve column constraints where

646486-- `View` or `Typedef`.

647487data SchemumType

648488 = Table TableType

649− | View RelationType

489+ | View RowType

650490 | Typedef PGType

651−

652−-- | The schema of a database consists of a list of aliased,

653−-- user-defined `SchemumType`s.

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+-}

654537type SchemaType = [(Symbol,SchemumType)]

655538

656−-- | Used in `Squeal.Postgresql.Manipulation.with`.

657−type family With

658− (relations :: RelationsType)

659− (schema :: SchemaType)

660− :: SchemaType where

661− With '[] schema = schema

662− With (alias ::: rel ': rels) schema =

663− alias ::: 'View rel ': With rels schema

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]

664559

665560-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas

666561-- the overloaded label, `fromLabel` is used for column references,

667562-- `label`s are used for enum terms. A `label` is called with

668563-- type application like `label @"beef"`.

669564class IsPGlabel (label :: Symbol) expr where label :: expr

670−instance label ~ label'

671− => IsPGlabel label (PGlabel label') where label = PGlabel

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

672569-- | A `PGlabel` unit type with an `IsPGlabel` instance

673570data PGlabel (label :: Symbol) = PGlabel

674−-- | Renders a label

675−renderLabel :: KnownSymbol label => proxy label -> ByteString

676−renderLabel (_ :: proxy label) =

677− "\'" <> fromString (symbolVal (Proxy @label)) <> "\'"

678−-- | Renders a list of labels

679−renderLabels

680− :: All KnownSymbol labels => NP PGlabel labels -> [ByteString]

681−renderLabels = hcollapse

682− . hcmap (Proxy @KnownSymbol) (K . renderLabel)

683−

684−-- | The `PG` type family embeds a subset of Haskell types

685−-- as Postgres basic types.

686−--

687−-- >>> :kind! PG LocalTime

688−-- PG LocalTime :: PGType

689−-- = 'PGtimestamp

690−type family PG (hask :: Type) :: PGType where

691− PG Bool = 'PGbool

692− PG Int16 = 'PGint2

693− PG Int32 = 'PGint4

694− PG Int64 = 'PGint8

695− PG Word16 = 'PGint2

696− PG Word32 = 'PGint4

697− PG Word64 = 'PGint8

698− PG Scientific = 'PGnumeric

699− PG Float = 'PGfloat4

700− PG Double = 'PGfloat8

701− PG Char = 'PGchar 1

702− PG Text = 'PGtext

703− PG Lazy.Text = 'PGtext

704− PG ByteString = 'PGbytea

705− PG Lazy.ByteString = 'PGbytea

706− PG LocalTime = 'PGtimestamp

707− PG UTCTime = 'PGtimestamptz

708− PG Day = 'PGdate

709− PG TimeOfDay = 'PGtime

710− PG (TimeOfDay, TimeZone) = 'PGtimetz

711− PG DiffTime = 'PGinterval

712− PG UUID = 'PGuuid

713− PG (NetAddr IP) = 'PGinet

714− PG Value = 'PGjson

715− PG ty = TypeError

716− ('Text "There is no Postgres basic type for " ':<>: 'ShowType ty)

717−

718−-- | The `EnumFrom` type family embeds Haskell enum types, ADTs with

719−-- nullary constructors, as Postgres enum types

720−--

721−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

722−-- >>> instance Generic Schwarma

723−-- >>> instance HasDatatypeInfo Schwarma

724−-- >>> :kind! EnumFrom Schwarma

725−-- EnumFrom Schwarma :: PGType

726−-- = 'PGenum '["Beef", "Lamb", "Chicken"]

727−type family EnumFrom (hask :: Type) :: PGType where

728− EnumFrom hask = 'PGenum (LabelsFrom hask)

729−

730−-- | The `LabelsFrom` type family calculates the constructors of a

731−-- Haskell enum type.

732−--

733−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

734−-- >>> instance Generic Schwarma

735−-- >>> instance HasDatatypeInfo Schwarma

736−-- >>> :kind! LabelsFrom Schwarma

737−-- LabelsFrom Schwarma :: [Type.ConstructorName]

738−-- = '["Beef", "Lamb", "Chicken"]

739−type family LabelsFrom (hask :: Type) :: [Type.ConstructorName] where

740− LabelsFrom hask =

741− ConstructorNamesOf (ConstructorsOf (DatatypeInfoOf hask))

742−

743−-- | The `CompositeFrom` type family embeds Haskell record types as

744−-- Postgres composite types, as long as the record fields

745−-- are `Maybe`s of Haskell types that can be embedded as basic types

746−-- with the `PG` type family.

747−--

748−-- >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic

749−-- >>> instance Generic Row

750−-- >>> instance HasDatatypeInfo Row

751−-- >>> :kind! CompositeFrom Row

752−-- CompositeFrom Row :: PGType

753−-- = 'PGcomposite '['("a", 'PGint2), '("b", 'PGtimestamp)]

754−type family CompositeFrom (hask :: Type) :: PGType where

755− CompositeFrom hask =

756− 'PGcomposite (ZipAs (FieldNamesFrom hask) (FieldTypesFrom hask))

757−

758−-- | >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic

759−-- >>> instance Generic Row

760−-- >>> instance HasDatatypeInfo Row

761−-- >>> :kind! FieldNamesFrom Row

762−-- FieldNamesFrom Row :: [Type.FieldName]

763−-- = '["a", "b"]

764−type family FieldNamesFrom (hask :: Type) :: [Type.FieldName] where

765− FieldNamesFrom hask = FieldNamesOf (FieldsOf (DatatypeInfoOf hask))

766−

767−-- | >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic

768−-- >>> instance Generic Row

769−-- >>> instance HasDatatypeInfo Row

770−-- >>> :kind! FieldTypesFrom Row

771−-- FieldTypesFrom Row :: [PGType]

772−-- = '['PGint2, 'PGtimestamp]

773−type family FieldTypesFrom (hask :: Type) :: [PGType] where

774− FieldTypesFrom hask = FieldTypesOf (RecordCodeOf hask (Code hask))

775−

776−-- | Calculates constructors of a datatype.

777−type family ConstructorsOf (datatype :: Type.DatatypeInfo)

778− :: [Type.ConstructorInfo] where

779− ConstructorsOf ('Type.ADT _module _datatype constructors) =

780− constructors

781− ConstructorsOf ('Type.Newtype _module _datatype constructor) =

782− '[constructor]

783−

784−-- | Calculates the name of a nullary constructor, otherwise

785−-- generates a type error.

786−type family ConstructorNameOf (constructors :: Type.ConstructorInfo)

787− :: Type.ConstructorName where

788− ConstructorNameOf ('Type.Constructor name) = name

789− ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

790− ('Text "ConstructorNameOf error: non-nullary constructor "

791− ':<>: 'Text name)

792− ConstructorNameOf ('Type.Record name _fields) = TypeError

793− ('Text "ConstructorNameOf error: non-nullary constructor "

794− ':<>: 'Text name)

795−

796−-- | Calculate the names of nullary constructors.

797−type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

798− :: [Type.ConstructorName] where

799− ConstructorNamesOf '[] = '[]

800− ConstructorNamesOf (constructor ': constructors) =

801− ConstructorNameOf constructor ': ConstructorNamesOf constructors

802−

803−-- | Calculate the fields of a datatype.

804−type family FieldsOf (datatype :: Type.DatatypeInfo)

805− :: [Type.FieldInfo] where

806− FieldsOf ('Type.ADT _module _datatype '[ 'Type.Record _name fields]) =

807− fields

808− FieldsOf ('Type.Newtype _module _datatype ('Type.Record _name fields)) =

809− fields

810−

811−-- | Calculate the name of a field.

812−type family FieldNameOf (field :: Type.FieldInfo) :: Type.FieldName where

813− FieldNameOf ('Type.FieldInfo name) = name

814−

815−-- | Calculate the names of fields.

816−type family FieldNamesOf (fields :: [Type.FieldInfo])

817− :: [Type.FieldName] where

818− FieldNamesOf '[] = '[]

819− FieldNamesOf (field ': fields) = FieldNameOf field ': FieldNamesOf fields

820−

821−-- | >>> :kind! FieldTypeOf (Maybe Int16)

822−-- FieldTypeOf (Maybe Int16) :: PGType

823−-- = 'PGint2

824−type family FieldTypeOf (maybe :: Type) where

825− FieldTypeOf (Maybe hask) = PG hask

826− FieldTypeOf ty = TypeError

827− ('Text "FieldTypeOf error: non-Maybe type " ':<>: 'ShowType ty)

828−

829−-- | Calculate the types of fields.

830−type family FieldTypesOf (fields :: [Type]) where

831− FieldTypesOf '[] = '[]

832− FieldTypesOf (field ': fields) = FieldTypeOf field ': FieldTypesOf fields

833−

834−-- | Inspect the code of an algebraic datatype and ensure it's a product,

835−-- otherwise generate a type error

836−type family RecordCodeOf (hask :: Type) (code ::[[Type]]) :: [Type] where

837− RecordCodeOf _hask '[tys] = tys

838− RecordCodeOf hask _tys = TypeError

839− ('Text "RecordCodeOf error: non-Record type " ':<>: 'ShowType hask)

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+101−74

@@ -1,7 +1,7 @@

11{-|

22Module: Squeal.PostgreSQL.Transaction

33Description: Squeal transaction control language

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

55Maintainer: eitan@morphism.tech

66Stability: experimental

@@ -9,98 +9,125 @@ Squeal transaction control language.

99-}

1010

1111{-# LANGUAGE

12− FlexibleContexts

12+ DataKinds

13+ , FlexibleContexts

1314 , LambdaCase

1415 , OverloadedStrings

16+ , TypeInType

1517#-}

1618

1719module Squeal.PostgreSQL.Transaction

1820 ( -- * Transaction

1921 transactionally

2022 , transactionally_

23+ , transactionallyRetry

24+ , ephemerally

25+ , ephemerally_

2126 , begin

2227 , commit

2328 , rollback

24− , transactionallySchema

25− , transactionallySchema_

2629 -- * Transaction Mode

2730 , TransactionMode (..)

2831 , defaultMode

2932 , longRunningMode

3033 , IsolationLevel (..)

31− , renderIsolationLevel

3234 , AccessMode (..)

33− , renderAccessMode

3435 , DeferrableMode (..)

35− , renderDeferrableMode

3636 ) where

3737

38−import Control.Exception.Lifted

39−import Control.Monad.Base

40−import Control.Monad.Trans.Control

41−import Data.ByteString

42−import Data.Monoid

43−import Generics.SOP

44−

45−import qualified Database.PostgreSQL.LibPQ as LibPQ

38+import UnliftIO

4639

4740import Squeal.PostgreSQL.Manipulation

4841import Squeal.PostgreSQL.Render

4942import Squeal.PostgreSQL.PQ

50−import Squeal.PostgreSQL.Schema

5143

52−-- | Run a schema invariant computation `transactionally`.

44+{- | Run a computation `transactionally`;

45+first `begin`,

46+then run the computation,

47+`onException` `rollback` and rethrow the exception,

48+otherwise `commit` and `return` the result.

49+-}

5350transactionally

54− :: (MonadBaseControl IO tx, MonadPQ schema tx)

51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

5552 => TransactionMode

5653 -> tx x -- ^ run inside a transaction

5754 -> tx x

5855transactionally mode tx = mask $ \restore -> do

59− _ <- begin mode

60− result <- restore tx `onException` rollback

61− _ <- commit

56+ manipulate_ $ begin mode

57+ result <- restore tx `onException` (manipulate_ rollback)

58+ manipulate_ commit

6259 return result

6360

64−-- | Run a schema invariant computation `transactionally_` in `defaultMode`.

61+-- | Run a computation `transactionally_`, in `defaultMode`.

6562transactionally_

66− :: (MonadBaseControl IO tx, MonadPQ schema tx)

63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

6764 => tx x -- ^ run inside a transaction

6865 -> tx x

6966transactionally_ = transactionally defaultMode

7067

71−-- | @BEGIN@ a transaction.

72−begin :: MonadPQ schema tx => TransactionMode -> tx (K Result NilRelation)

73−begin mode = manipulate . UnsafeManipulation $

74− "BEGIN" <+> renderTransactionMode mode <> ";"

68+{- |

69+`transactionallyRetry` a computation;

70+

71+* first `begin`,

72+* then `try` the computation,

73+ - if it raises a serialization failure then `rollback` and restart the transaction,

74+ - if it raises any other exception then `rollback` and rethrow the exception,

75+ - otherwise `commit` and `return` the result.

76+-}

77+transactionallyRetry

78+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

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

75112

76−-- | @COMMIT@ a schema invariant transaction.

77−commit :: MonadPQ schema tx => tx (K Result NilRelation)

78−commit = manipulate $ UnsafeManipulation "COMMIT;"

113+{- | Run a computation `ephemerally` in `defaultMode`. -}

114+ephemerally_

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

79123

80−-- | @ROLLBACK@ a schema invariant transaction.

81−rollback :: MonadPQ schema tx => tx (K Result NilRelation)

82−rollback = manipulate $ UnsafeManipulation "ROLLBACK;"

124+-- | @COMMIT@ a transaction.

125+commit :: Manipulation_ schemas () ()

126+commit = UnsafeManipulation "COMMIT"

83127

84−-- | Run a schema changing computation `transactionallySchema`.

85−transactionallySchema

86− :: MonadBaseControl IO io

87− => TransactionMode

88− -> PQ schema0 schema1 io x

89− -> PQ schema0 schema1 io x

90−transactionallySchema mode u = PQ $ \ conn -> mask $ \ restore -> do

91− _ <- liftBase . LibPQ.exec (unK conn) $

92− "BEGIN" <+> renderTransactionMode mode <> ";"

93− x <- restore (unPQ u conn)

94− `onException` (liftBase (LibPQ.exec (unK conn) "ROLLBACK"))

95− _ <- liftBase $ LibPQ.exec (unK conn) "COMMIT"

96− return x

97−

98−-- | Run a schema changing computation `transactionallySchema_` in `DefaultMode`.

99−transactionallySchema_

100− :: MonadBaseControl IO io

101− => PQ schema0 schema1 io x

102− -> PQ schema0 schema1 io x

103−transactionallySchema_ = transactionallySchema defaultMode

128+-- | @ROLLBACK@ a transaction.

129+rollback :: Manipulation_ schemas () ()

130+rollback = UnsafeManipulation "ROLLBACK"

104131

105132-- | The available transaction characteristics are the transaction `IsolationLevel`,

106133-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

@@ -113,7 +140,7 @@ data TransactionMode = TransactionMode

113140-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

114141-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

115142defaultMode :: TransactionMode

116−defaultMode = TransactionMode Serializable ReadWrite NotDeferrable

143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable

117144

118145-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

119146-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

@@ -122,12 +149,12 @@ longRunningMode :: TransactionMode

122149longRunningMode = TransactionMode Serializable ReadOnly Deferrable

123150

124151-- | Render a `TransactionMode`.

125−renderTransactionMode :: TransactionMode -> ByteString

126−renderTransactionMode mode =

127− "ISOLATION LEVEL"

128− <+> renderIsolationLevel (isolationLevel mode)

129− <+> renderAccessMode (accessMode mode)

130− <+> renderDeferrableMode (deferrableMode mode)

152+instance RenderSQL TransactionMode where

153+ renderSQL mode =

154+ "ISOLATION LEVEL"

155+ <+> renderSQL (isolationLevel mode)

156+ <+> renderSQL (accessMode mode)

157+ <+> renderSQL (deferrableMode mode)

131158

132159-- | The SQL standard defines four levels of transaction isolation.

133160-- The most strict is `Serializable`, which is defined by the standard in a paragraph

@@ -178,12 +205,12 @@ data IsolationLevel

178205 deriving (Show, Eq)

179206

180207-- | Render an `IsolationLevel`.

181−renderIsolationLevel :: IsolationLevel -> ByteString

182−renderIsolationLevel = \case

183− Serializable -> "SERIALIZABLE"

184− ReadCommitted -> "READ COMMITTED"

185− ReadUncommitted -> "READ UNCOMMITTED"

186− RepeatableRead -> "REPEATABLE READ"

208+instance RenderSQL IsolationLevel where

209+ renderSQL = \case

210+ Serializable -> "SERIALIZABLE"

211+ ReadCommitted -> "READ COMMITTED"

212+ ReadUncommitted -> "READ UNCOMMITTED"

213+ RepeatableRead -> "REPEATABLE READ"

187214

188215-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

189216-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

@@ -200,10 +227,10 @@ data AccessMode

200227 deriving (Show, Eq)

201228

202229-- | Render an `AccessMode`.

203−renderAccessMode :: AccessMode -> ByteString

204−renderAccessMode = \case

205− ReadWrite -> "READ WRITE"

206− ReadOnly -> "READ ONLY"

230+instance RenderSQL AccessMode where

231+ renderSQL = \case

232+ ReadWrite -> "READ WRITE"

233+ ReadOnly -> "READ ONLY"

207234

208235-- | The `Deferrable` transaction property has no effect

209236-- unless the transaction is also `Serializable` and `ReadOnly`.

@@ -219,7 +246,7 @@ data DeferrableMode

219246 deriving (Show, Eq)

220247

221248-- | Render a `DeferrableMode`.

222−renderDeferrableMode :: DeferrableMode -> ByteString

223−renderDeferrableMode = \case

224− Deferrable -> "DEFERRABLE"

225− NotDeferrable -> "NOT DEFERRABLE"

249+instance RenderSQL DeferrableMode where

250+ renderSQL = \case

251+ Deferrable -> "DEFERRABLE"

252+ NotDeferrable -> "NOT DEFERRABLE"

squeal-postgresql/test/Doc.hsnew file+6

@@ -0,0 +1,6 @@

1+module Main (main) where

3+import Test.DocTest

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

3+_A bridge between SQL and Haskell_

5+by [@Raveline](https://github.com/raveline)

7+---

9+# Rationale

10+

11+Using `postgresql-simple` you have a typical "Trial, error, despair" workflow:

12+

13+- Write query manually or semi-automatically

14+

15+- Write haskell code using the query

16+

17+- Pray that the query syntax is correct

18+

19+- Pray that it returns what you want

20+

21+- Realize the inefficiency of prayer when it comes to SQL

22+

23+- Iterate till it works

24+

25+---

26+

27+![Can't take this anymore](http://gif.eraveline.eu/static/img/0x16e.gif)

28+

29+---

30+

31+# Use your best friend: GHC

32+

33+Squeal provides several eDSL to make your SQL typesafe:

34+

35+- Type level eDSL to express schema;

36+

37+- Value level eDSL to manipulate schema (plus migration, yeehaw !);

38+

39+- Type level eDSL to express queries;

40+

41+- Value level eDSL to perform queries

42+

43+However, it's not an ORM. There's no caching, lazy loading - you retain control over your memory. Also, joins - and mostly aggregation after joins - have to be handled manually.

44+

45+---

46+

47+# Part I. Schema & migration

48+

49+---

50+

51+# The Schema

52+

53+- The schema will be used to validate _everything_: migration, queries, etc.

54+

55+- A schema is mostly a collection of tables.

56+

57+- In this presentation, we will create a very basic database modeling a parliament. We will store _members of parliament_ and _parliamentary groups_.

58+

59+- A simple Schema to represent a Parliament could be:

60+

61+```haskell

62+type Schema = '[ "mp" ::: 'Table MemberOfParliament

63+ , "groupp" ::: 'Table ParliamentGroup ]

64+```

65+

66+---

67+

68+> _note_ We need the `DataKinds` extension to be able to express heterogenous lists containing

69+> specific types like this one.

70+

71+> You can perfectly call your table "group" and not "groupp" even though it is a

72+> keyword in SQL - Squeal queries will be properly escaped.

73+

74+---

75+

76+# A small example

77+

78+```haskell

79+type ParliamentaryGroup =

80+ '[ "pk_groupp" ::: 'PrimaryKey '["groupp_id"]]

81+ :=>

82+ '[ "groupp_id" ::: 'NoDef :=> 'NotNull 'PGuuid

83+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

84+ ]

85+```

86+

87+- That's a whole simple table defined in one go.

88+

89+- `:::` lets us define a column or a constraint.

90+

91+- `:=>` associates the constraints to the column.

92+

93+- Let's split constraints and column to study the syntax a bit more.

94+

95+---

96+

97+> _note_ We are using `:::` and `:=>` to quickly express associations when writing

98+> our schema. We need the `TypeOperators` extension.]

99+

100+---

101+

102+![What does this means ?!](http://gif.eraveline.eu/static/img/0x27e.gif)

103+

104+---

105+

106+# Defining a table

107+

108+```haskell

109+type MemberOfParliament =

110+ '[ "pk_mp" ::: 'PrimaryKey '["mp_id"]

111+ , "fk_mp_groupp" ::: 'ForeignKey '["mp_group"] "groupp" '["groupp_id"]

112+ ] :=> MpCols

113+```

114+

115+- A table is a collection of constraints associated to a collection of columns.

116+

117+- We defined a table named "mp".

118+

119+- It has a constraint named "pk_mp", defining its primary key on column "mp_id".

120+

121+- It has a constraint named "fk_mp_groupp" defining a foreign key on column "mg_group", connected to the column "groupp_id" of table "groupp".

122+

123+- These constraints will be associated to the columns defined in `MpCols`.

124+

125+---

126+

127+# Defining columns

128+

129+```haskell

130+type MpCols =

131+ '[ "mp_id" ::: 'NoDef :=> 'NotNull 'PGuuid

132+ , "first_name" ::: 'NoDef :=> 'NotNull 'PGtext

133+ , "last_name" ::: 'NoDef :=> 'NotNull 'PGtext

134+ ]

135+```

136+

137+- A listing of column associate, for each element:

138+

139+ * a name;

140+

141+ * the mention of an eventual default value;

142+

143+ * the nullability;

144+

145+ * the type (obviously).

146+

147+---

148+

149+> _note_ GHC is already helping. If I named the "mp_id" column differently,

150+> GHC would yell because I promised a primary key constraint on a column named `mp_id`, so there must be one.]

151+

152+---

153+

154+# Implementating the schema

155+

156+- We will carry this schema type pretty much everywhere.

157+

158+- But before we play with this schema, we need to implement it.

159+

160+---

161+

162+```haskell

163+setup :: Definition '[] Schema

164+setup =

165+ createTable #groupp

166+ ( notNullable uuid `as` #groupp_id

167+ :* notNullable text `as` #name)

168+ ( primaryKey #groupp_id `as` #pk_groupp )

169+ >>> createTable #mp

170+ ( notNullable uuid `as` #mp_id

171+ :* notNullable text `as` #first_name

172+ :* notNullable text `as` #last_name

173+ :* notNullable text `as` #mp_group)

174+ ( primaryKey #mp_id `as` #pk_mp

175+ :* foreignKey #mp_group #groupp #groupp_id

176+ OnDeleteCascade OnUpdateCascade

177+ `as` #fk_mp_groupp)

178+```

179+

180+---

181+

182+# Damn, that's verbose

183+

184+- Yes. But you need verbosity to get type safety.

185+

186+- On the plus side, it's fairly straightforward.

187+

188+- You use `:*` to compose the element of the heterogenous list of columns.

189+

190+- You use `>>>` to compose table creation.

191+

192+> _note_ The compiler will catch any mistype between Schema and

193+> definition; wrong nullability, wrong type, wrong name, etc.

194+

195+---

196+

197+> _note_ You'll also need `OverloadedLabels`, for naming stuff.

198+> This is mostly to avoid having to write manual proxies all

199+> the time and for convenience.

200+

201+---

202+

203+# Setting up the schema

204+

205+- Squeal comes with a very good migration manager, handling _upgrades_ AND

206+_downgrades_.

207+

208+- A migration is a simple type:

209+

210+```haskell

211+Migration io schema0 schema1

212+```

213+

214+- The first parameter is a BaseMonad (typically, IO).

215+

216+- The second parameter is "the current schema of your DB".

217+

218+- The last one is "what you will migrate to".

219+

220+- The `Definition` type used to define upgrade and downgrade functions use the

221+ same logic (from one schema to the other).

222+

223+---

224+

225+# Defining our first migration

226+

227+- We have the setup bit, we need the teardown:

228+

229+```haskell

230+tearDown :: Definition Schema '[]

231+tearDown = dropTable #mp >>> dropTable #groupp

232+```

233+

234+> _note_ GHC will also detect the _proper_ order of what you typed in

235+> downgrade and upgrade should there be any conflict (with foreign keys).

236+

237+```haskell

238+initDB :: Migration IO '[] Schema

239+initDB =

240+ Migration { name = "Schema creation"

241+ , up = void $ define setup

242+ , down = void $ define tearDown }

243+```

244+

245+---

246+

247+# Simple migrator example

248+

249+```haskell

250+main :: IO ()

251+main = do

252+ printSQL setup

253+ void $ withConnection connectionString $

254+ migrateUp $ single initDB

255+```

256+

257+- We print the migration query; you can do this for all queries generated through Squeal.

258+

259+- We use `migrateUp` to perform the migration.

260+

261+- You can run several migration at the same time, to run only one use `single`.

262+

263+---

264+

265+![That was easy](http://gif.eraveline.eu/static/img/0x47f.gif)

266+

267+---

268+

269+# Part II. Insertions

270+

271+---

272+

273+# Manipulations & Queries

274+

275+Besides the specific case of migration, you will mostly perform:

276+

277+- `Manipulation` : inserting, updating and deleting data.

278+

279+- `Query` : fetching data.

280+

281+- Both types are parametric over the same things:

282+

283+ * A schema

284+

285+ * Input parameters

286+

287+ * Output

288+

289+- Simplified, they look like this:

290+

291+```haskell

292+Manipulation schema params columns

293+

294+Query schema params columns

295+```

296+

297+

298+---

299+

300+# Our Haskell model

301+

302+```haskell

303+type Parliament = [Group]

304+

305+data Group =

306+ Group { name :: Text

307+ , members :: [MemberOfParliament] }

308+

309+data MemberOfParliament =

310+ MemberOfParliament { firstName :: Text

311+ , lastName :: Text }

312+```

313+

314+> _note_ We didn't use anything from Squeal.

315+> The model can be entirely separated from the persistence layer.

316+

317+---

318+

319+# Inserting a Parliamentary Group

320+

321+- A group is very simple: it's a uuid and a name. Let's define our params:

322+

323+```haskell

324+type GroupInsertionParams = '[ 'NotNull 'PGuuid

325+ , 'NotNull 'PGtext ]

326+```

327+

328+- Params are not named, but they are indexed. You just need nullability and type.

329+

330+---

331+

332+```haskell

333+groupInsertion :: Manipulation Schema GroupInsertionParams '[]

334+groupInsertion =

335+ insertRow_ #groupp ( Set (param @1) `as` #groupp_id

336+ :* Set (param @2) `as` #name )

337+```

338+

339+---

340+

341+- `TypeApplication` lets us use the index of parameters (counting from 1).

342+

343+- Once again: all this is checked by the compiler. Wrong name, wrong type... you'll get a compile error.

344+

345+- `insertRow_` is a simplified version of `insertRow`. `insertRow` lets you express a `RETURNING` clause and the expected behaviour in case of conflict.

346+

347+---

348+

349+_Inserting a Member of Parliament_

350+# Doing an INSERT INTO ... SELECT

351+

352+- We could create a naive query that takes MP uuid, first name, last name and group uuid...

353+

354+---

355+

356+- But that's boring. So let's use the `INSERT INTO ... SELECT`.

357+

358+---

359+

360+- We will build a query that will return as constants our MP's uuid, first name and last name...

361+

362+---

363+

364+- ... and fetch the uuid of a group given the name of the group.

365+

366+---

367+

368+- There's a `insertQuery` utility function for that. All we have to do is write the `select` !

369+

370+```haskell

371+mpInsertion :: Manipulation Schema MpParams '[]

372+mpInsertion =

373+ insertQuery_ #mp selectGroup -- we just have to write selectGroup !

374+```

375+

376+---

377+

378+_Inserting a Member of Parliament_

379+# The query type

380+

381+- A query looks just like a `Manipulation`:

382+

383+```haskell

384+Query schema params returns

385+```

386+

387+- Returns use a special syntax, that demands names, nullability and types:

388+

389+```haskell

390+type ExampleReturnType = '[ "some_column" ::: 'NotNull 'PGuuid

391+ , "other_column" ::: 'Null 'PGtext ]

392+```

393+

394+- It is not the same as the column definition we used in the schema. That one also expects that you specify, for each column, an eventual default:

395+

396+```haskell

397+type ExampleSchemaCols =

398+ '[ "some_column" ::: 'NoDef :=> 'NotNull 'PGuuid

399+ , "other_column" ::: 'NoDef :=> 'Null 'PGtext ]

400+```

401+

402+---

403+

404+_Inserting a Member of Parliament_

405+# Don't rewrite column definitions

406+

407+- We want our return type to be "all columns from table MP expressed as return type".

408+

409+- But we cannot reuse our neat `MpCols` alias, since the type do not match as we've just seen.

410+

411+- Hopefully, there's a neat Type Family that will let you convert any table you defined to the type of the equivalent row: `TableToRow`.

412+

413+- We finally have the signature for our SELECT query.

414+

415+```haskell

416+selectGroup :: Query Schema MpParams (TableToRow MemberOfParliament)

417+```

418+

419+---

420+

421+_Inserting a Member of Parliament_

422+# Our final Select query

423+

424+- Our intermediate query looks like this:

425+

426+```haskell

427+selectGroup =

428+ select

429+ ( param @1 `as` #mp_id

430+ :* param @2 `as` #first_name

431+ :* param @3 `as` #last_name

432+ :* #groupp ! #groupp_id `as` #mp_group

433+ )

434+ ( from (table #groupp)

435+ & where_ ( #groupp ! #name .== param @4 )

436+ )

437+```

438+

439+- The first three columns are constant defined through our params;

440+

441+- ... we alias the column name using `as`...

442+

443+- ... and when we need the result from the table we use the `#table ! #column` syntax.

444+

445+- We'll go back to the "from" block later.

446+

447+---

448+

449+# Dealing with the connection context

450+

451+- Queries are runned in a connection context:

452+

453+ * When dealing with a single-connection context, use the type `PQ`.

454+

455+ * When dealing with a pool of connection, use the type `PoolPQ`.

456+

457+- Or get rid of the context and use `mtl` style, with the typeclass `MonadPQ`.

458+

459+- We'll use that to demonstrate how to actually run our queries.

460+

461+---

462+

463+# Inserting a whole group

464+

465+```haskell

466+insertGroup :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()

467+insertGroup g@(Group name _) = do

468+ uuid' <- liftBase nextRandom

469+ void $ manipulateParams groupInsertion (uuid', name)

470+ insertMps g

471+```

472+

473+- Remember that we defined a group as a name and a list of MPs.

474+

475+- We are in `MonadBaseControl`, so we cannot use `liftIO`, we need `liftBase`.

476+

477+- To perform a simple insertion, use `manipulateParams`. It takes into parameter

478+instances of `ToParam`, but you will typically use tuples or Generic-SOP.

479+

480+---

481+

482+# Inserting a bunch of MPs

483+

484+```haskell

485+insertMps :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()

486+insertMps (Group groupName mps) =

487+ let tuplify Mp{..} = (, firstName, lastName, groupName) <$> nextRandom

488+ params = traverse tuplify mps

489+ in void $ liftBase params >>= traversePrepared mpInsertion

490+```

491+

492+- This time, we want to do a `preparedStatement`. We'll use `traversePrepare`

493+which behaves like `manipulateParams`, but expect a list of `ToParam`

494+instances.

495+

496+- We build our tuple manually again, mostly because we want to generate UUID on

497+the fly and we don't want to have them in our model.

498+

499+---

500+

501+# Inserting a whole parliament

502+

503+```haskell

504+insertParliament ::

505+ (MonadPQ Schema m, MonadBaseControl IO m) => Parliament -> m ()

506+insertParliament = traverse_ insertGroup

507+```

508+

509+- That's simple enough !

510+

511+- If we want to be a bit safer, though, we can wrap this call in a

512+`transactionally_` function, which will put all that in a transaction.

513+

514+---

515+

516+![Very simple](https://media1.tenor.com/images/0188c63209aced59f1583e1ca94e509e/tenor.gif?itemid=3550689)

517+

518+

519+---

520+

521+# Part III. Selects

522+

523+---

524+

525+# Composable queries

526+

527+- Building basic queries is easy, and is well documented.

528+

529+- However, the real interest of a tool like Squeal is in DRYness, and the documentation is still lacking in "how-to" related to composability.

530+

531+- I'll build an example showing how column selections and from clause can be factorized.

532+

533+- We want to write two queries:

534+

535+ * One to get all members of a specific group.

536+

537+ * One to get all the parliament.

538+

539+---

540+

541+# Decomposing a `Query`

542+

543+- A query typically stars with `select` (variants are available).

544+

545+- It then takes:

546+

547+ * A heterogenous list of fields with a scary signature;

548+

549+ * A virtual table (the from clause and filter clauses), called a `TableExpression`.

550+

551+- And return fields. Ours will look like this:

552+

553+```haskell

554+type GroupRowResult =

555+ '[ "groupName" ::: 'NotNull 'PGtext

556+ , "firstName" ::: 'NotNull 'PGtext

557+ , "lastName" ::: 'NotNull 'PGtext ]

558+```

559+

560+---

561+

562+# The Table Expression

563+

564+- It necessarily contains a `fromClause` (table, view or subquery, plus optional joins).

565+

566+- You can add where, groups, "HAVING" clause, order, etc.

567+

568+- `from` creates a basic `TableExpression` that you extend through various function to add clauses.

569+

570+- For our queries, we will share a common `FromClause`.

571+

572+---

573+

574+# The From Clause

575+

576+```

577+FromClause schema params from

578+```

579+

580+- We need Schema, input parameters and a `FromType` giving the available fields of the expression.

581+

582+- In our case, we'll join the table `mp` and the table `groupp`, meaning the `from` will be all fields of these tables.

583+

584+- We can use `TableToRow` to be more DRY:

585+

586+```haskell

587+type BaseParliamentSelection =

588+ '[ "g" ::: TableToRow GroupCols

589+ , "m" ::: TableToRow MpCols ]

590+```

591+

592+> _note_ We've also put everything with table aliases: "g" and "m".

593+

594+---

595+

596+# Writing our from clause

597+

598+```haskell

599+baseParliamentTables ::

600+ FromClause Schema (param :: [NullityType]) BaseParliamentSelection

601+baseParliamentTables =

602+ table

603+ (#groupp `as` #g)

604+ & innerJoin

605+ (table (#mp `as` #m))

606+ (#m ! #mp_group .== #g ! #groupp_id)

607+```

608+

609+- When picking "from" something, you need to specify the type with a function: `table` for a table, `view` for a view, etc.

610+

611+- All joins are available. `innerJoin` is the most basic one. It takes the joined table and the joining condition.

612+

613+- We have to specifiy the type of `param` (current limitation of the lib), even though _any_ params will be compatible with this, so we can plug `where` clauses depending on params should we need to !

614+

615+---

616+

617+# Typing the common selection

618+

619+- Both our querie will need the same fields. This has to be factorized too.

620+

621+- The scary signature of selection fields:

622+

623+```haskell

624+NP (Aliased (Expression schema from grouping params)) cols

625+```

626+

627+- `NP` is for heterogenous lists ("n-ary product").

628+

629+- `from` is the virtual table type, so our `BaseParliamentSelection`.

630+

631+- `grouping` is there to make a distinction between aggregated / unaggregated queries.

632+

633+- And finally, cols is the return type.

634+

635+---

636+

637+# Our common selection

638+

639+```haskell

640+groupSelection ::

641+ NP (Aliased (Expression Schema BaseParliamentSelection 'Ungrouped param))

642+ GroupRowResult

643+groupSelection =

644+ #g ! #name `as` #groupName

645+ :* #m ! #first_name `as` #firstName

646+ :* #m ! #last_name `as` #lastName

647+```

648+

649+- I hope you like big signatures.

650+

651+- But it's what let GHC checks that all alias and columns are available.

652+

653+- And that you're returning what you really intend to return.

654+

655+---

656+

657+# Putting it all together

658+

659+```haskell

660+selectParliament :: Query Schema '[] GroupRowResult

661+selectParliament =

662+ select groupSelection (from baseParliamentTables)

663+```

664+

665+```haskell

666+selectGroupMembers :: Query Schema '[ 'NotNull 'PGtext] GroupRowResult

667+selectGroupMembers =

668+ select groupSelection

669+ (from baseParliamentTables

670+ & where_ (#g ! #name .== param @1))

671+```

672+

673+- That is fairly DRY. And _entirely typesafe_.

674+

675+---

676+

677+# Actually fetching the data

678+

679+- We'll build an intermediary datatype representing our rows.

680+

681+- We'll make it match our row.

682+

683+- And we'll add generic-SOP so that we can build them from query results.

684+

685+```haskell

686+type GroupRowResult =

687+ '[ "groupName" ::: 'NotNull 'PGtext

688+ , "firstName" ::: 'NotNull 'PGtext

689+ , "lastName" ::: 'NotNull 'PGtext ]

690+```

691+

692+```haskell

693+data GroupRow =

694+ GroupRow { groupName :: Text

695+ , firstName :: Text

696+ , lastName :: Text }

697+ deriving (Generic)

698+

699+instance SOP.Generic GroupRow

700+instance SOP.HasDatatypeInfo GroupRow

701+```

702+

703+---

704+

705+# Aggregate result logic

706+

707+- We will get tabular, SQL data.

708+

709+- Our results will be `[GroupRow]`.

710+

711+- We'll build `Groups` from this:

712+

713+```haskell

714+buildGroup :: NE.NonEmpty GroupRow -> Group

715+buildGroup grs =

716+ let buildMP (GroupRow _ f l) = Mp f l

717+ name = groupName . NE.head $ grs

718+ members = NE.toList (buildMP <$> grs)

719+ in Group{..}

720+

721+rowToGroups :: [GroupRow] -> [Group]

722+rowToGroups =

723+ let grouped = fmap NE.fromList . L.groupBy ((==) `on` groupName)

724+ in fmap buildGroup . grouped

725+```

726+

727+---

728+

729+# Finally calling our queries

730+

731+- Query with params will use `runQueryParams`.

732+

733+- Query without params will use `runQuery`.

734+

735+- Result is inside a `MonadPQ` and of type `K` from generic-sop.

736+

737+- You get your actual result using `getRows`. Exemple:

738+

739+```haskell

740+getParliament :: (MonadPQ Schema m, MonadBaseControl IO m) => m [Group]

741+getParliament = do

742+ res <- runQuery selectParliament

743+ rows <- getRows res

744+ pure $ rowToGroups rows

745+```

746+

747+- In real life of course you'll write:

748+

749+```haskell

750+getParliament =

751+ rowToGroups <$> (runQuery selectParliament >>= getRows)

752+```

753+

754+---

755+

756+# Our query with params

757+

758+```haskell

759+getGroupMembers ::

760+ (MonadPQ Schema m, MonadBaseControl IO m) => Text -> m (Maybe Group)

761+getGroupMembers =

762+ listToMaybe . rowToGroups <$>

763+ (runQueryParams selectGroupMembers (Only t) >>= getRows)

764+```

765+

766+- And that's it.

767+

768+---

769+

770+![Eazy](https://media.tenor.com/images/8fc7c4077efe11b4a3a3b9ae4e643e87/tenor.gif)

771+

772+---

773+

774+# Conclusion

775+

776+---

777+

778+# Pros & Cons

779+

780+- Not everything is included: some cool stuff like array_agg and window functions are not available yet.

781+

782+- But development is _very_ active. `IN` clauses were missing but were added in the 4.0 released recently.

783+

784+- It's bleeding edge. You need latest LTS to be comfortable and psql >= 9.5.

785+

786+- It's Postgres-only but I would say that's a feature. Multi-DB tools are even more complex.

787+

788+- The author & maintainer is <3.

789+

790+- Typesafe. 'nuff said.

791+

792+---

793+

794+# Thank you !

stack.yaml+6−1

@@ -1,3 +1,8 @@

1−resolver: lts-11.15

1+resolver: nightly-2019-07-14

22packages:

33- squeal-postgresql

5+extra-deps:

6+- unliftio-pool-0.2.1.0

7+- github: morphismtech/free-categories

8+ commit: c0e555fbefb5c21619e532264c4dfeac556d0630