3b65e8f...dev · squeal

git.iko.soy/squeal

53 files changed+10509−5390

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+532−15

@@ -1,9 +1,410 @@

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+

3403### Version 0.4

4404

5−Version 0.4 of strengthens Squeal's type system, adds

6−support for multidimensional arrays, improves `with` statements,

405+Version 0.4 strengthens Squeal's type system, adds

406+support for multidimensional arrays, improves support

407+for container type, improves `with` statements,

7408improves runtime exceptions, accomodates SQL's three-valued logic,

8409adds subquery expressions, and adds table and view type expressions.

9410

@@ -49,7 +450,7 @@ type family RowPG (hask :: Type) :: RowType

49450

50451Let's look at these one by one.

51452

52−`PG` was introduced in Squeal 0.3. It's a closed type family that

453+`PG` was introduced in Squeal 0.3. It was a closed type family that

53454associates some Haskell types to their obvious corresponding Postgres

54455types like `PG Double = 'PGfloat8`. It only worked on base types,

55456no arrays or composites. Squeal 0.4 extends it to

@@ -73,8 +474,11 @@ into lists of `NullityType`s in the logical way, e.g.

73474

74475```Haskell

75476>>> data Person = Person { name :: Text, age :: Int32 } deriving GHC.Generic

76−>>> instance Generic Person

77−>>> instance HasDatatypeInfo Person

477+>>> instance SOP.Generic Person

478+>>> instance SOP.HasDatatypeInfo Person

479+>>> :kind! TuplePG Person

480+TuplePG Person :: [NullityType]

481+= '['NotNull 'PGtext, 'NotNull 'PGint4]

78482>>> :kind! RowPG Person

79483RowPG Person :: [(Symbol, NullityType)]

80484= '["name" ::: 'NotNull 'PGtext, "age" ::: 'NotNull 'PGint4]

@@ -91,9 +495,6 @@ boilerplate signature you can reuse these with the help of `TuplePG` and `RowPG`

91495For instance:

92496

93497```Haskell

94−>>> data Person = Person { name :: Text, age :: Int32 } deriving GHC.Generic

95−>>> instance SOP.Generic Person

96−>>> instance SOP.HasDatatypeInfo Person

97498>>> :{

98499let

99500 query :: Query '["user" ::: 'View (RowPG Person)] (TuplePG (Only Int32)) (RowPG Person)

@@ -106,8 +507,8 @@ let

106507In addition to being able to encode and decode basic Haskell types

107508like `Int16` and `Text`, Squeal 0.4 permits you to encode and decode Haskell types to

108509Postgres array types. The `Vector` type corresponds to to variable length arrays.

109−And thanks to [Mike Ledger](https://github.com/mikeplus64) for the idea,

110−and homogeneous tuples correspond to fixed length arrays. We can even

510+And thanks to an idea from [Mike Ledger](https://github.com/mikeplus64),

511+homogeneous tuples correspond to fixed length arrays. We can even

111512create multi-dimensional fixed length arrays. Let's see an example.

112513

113514```Haskell

@@ -146,6 +547,120 @@ void . withConnection "host=localhost port=5432 dbname=exampledb" $ do

146547True

147548```

148549

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+

149664**With**

150665

151666Squeal 0.3 supported WITH statements but there's a couple problems with them.

@@ -160,9 +675,9 @@ with

160675 -> Manipulation schema params results

161676```

162677

163−The first problem is that with only works with `Manipulations`.

164−It can work on Querys by using queryStatement but it still will

165−return a Manipulation. We can fix this issue by making it a

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

166681method of a type class with instances for both `Query` and `Manipulation`.

167682

168683The second problem is that all the common table expressions

@@ -213,6 +728,8 @@ in printSQL query

213728:}

214729WITH "t2" AS (SELECT * FROM "t1" AS "t1"), "t3" AS (SELECT * FROM "t2" AS "t2") SELECT * FROM "t3" AS "t3"

215730

731+>>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

732+

216733>>> :{

217734let

218735 manipulation :: Manipulation

@@ -233,7 +750,7 @@ In previous versions of Squeal, conditions followed classical two valued logic

233750of `true` and `false`.

234751

235752```Haskell

236−-- Squeal 0.2

753+-- Squeal 0.3

237754type Condition schema from grouping params =

238755 Expression schema from grouping params ('NotNull 'PGbool)

239756```

@@ -245,7 +762,7 @@ of being less confusing evaporated I decided to switch to three valued logic

245762of `true`, `false` and `null_`.

246763

247764```Haskell

248−-- Squeal 0.3

765+-- Squeal 0.4

249766type Condition schema from grouping params =

250767 Expression schema from grouping params ('Null 'PGbool)

251768```

squeal-postgresql/exe/Example.hs+34−37

@@ -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)

@@ -39,10 +38,13 @@ 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

4749 ( serial `as` #id :*

4850 (text & notNullable) `as` #name :*

@@ -51,60 +53,55 @@ setup =

5153 >>>

5254 createTable #emails

5355 ( serial `as` #id :*

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

55− (text & nullable) `as` #email )

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

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

5658 ( primaryKey #id `as` #pk_emails :*

5759 foreignKey #user_id #users #id

5860 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))

5975

60−teardown :: Definition Schema '[]

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

62−

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

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

65−insertUser = insertRows #users

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

67− OnConflictDoNothing (Returning (#id `as` #fromOnly))

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 ) []

74− OnConflictDoNothing (Returning Nil)

75−

76−getUsers :: Query Schema '[]

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

78− , "userEmail" ::: 'Null 'PGtext

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

80−getUsers = select

76+getUsers :: Query_ Schemas () User

77+getUsers = select_

8178 (#u ! #name `as` #userName :* #e ! #email `as` #userEmail :* #u ! #vec `as` #userVec)

8279 ( from (table (#users `as` #u)

8380 & 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+59−17

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

11name: squeal-postgresql

2−version: 0.4.0.0

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

@@ -37,15 +65,14 @@ 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

@@ -56,39 +83,55 @@ library

5683 , text >= 1.2.3.0

5784 , time >= 1.8.0.2

5885 , transformers >= 0.5.2.0

59− , transformers-base >= 0.4.4

86+ , unliftio >= 0.2.10

87+ , unliftio-pool >= 0.2.1.0

6088 , uuid-types >= 1.0.3

6189 , vector >= 0.12.0.1

6290

63−test-suite squeal-postgresql-doctest

91+test-suite doctest

6492 default-language: Haskell2010

6593 type: exitcode-stdio-1.0

6694 hs-source-dirs: test

6795 ghc-options: -Wall

68− main-is: DocTest.hs

96+ main-is: Doc.hs

6997 build-depends:

7098 base >= 4.10.0.0

7199 , doctest >= 0.11.4

100+ , squeal-postgresql

72101

73−test-suite squeal-postgresql-specs

102+test-suite properties

74103 default-language: Haskell2010

75104 type: exitcode-stdio-1.0

76− hs-source-dirs: test/Specs

77− ghc-options: -Wall -main-is Specs

78− main-is: Specs.hs

79− other-modules: ExceptionHandling

105+ hs-source-dirs: test

106+ ghc-options: -Wall

107+ main-is: Property.hs

80108 build-depends:

81109 base >= 4.10.0.0

82110 , 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

83127 , generics-sop >= 0.3.1.0

84128 , hspec >= 2.4.8

129+ , mtl >= 2.2.2

85130 , squeal-postgresql

86131 , text >= 1.2.2.2

87− , transformers >= 0.5.2.0

88− , transformers-base >= 0.4.4

89132 , vector >= 0.12.0.1

90133

91−executable squeal-postgresql-example

134+executable example

92135 default-language: Haskell2010

93136 hs-source-dirs: exe

94137 ghc-options: -Wall

@@ -101,5 +144,4 @@ executable squeal-postgresql-example

101144 , squeal-postgresql

102145 , text >= 1.2.2.2

103146 , transformers >= 0.5.2.0

104− , transformers-base >= 0.4.4

105147 , vector >= 0.12.0.1

squeal-postgresql/src/Squeal/PostgreSQL.hs+101−95

@@ -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

@@ -68,8 +66,8 @@ 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

7472 ( serial `as` #id :*

7573 (text & notNullable) `as` #name )

@@ -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

@@ -104,51 +102,49 @@ 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)

123− OnConflictDoNothing (Returning (#id `as` #fromOnly))

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 )

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

146+ getUsers :: Query_ Schemas () User

147+ getUsers = select_

152148 (#u ! #name `as` #userName :* #e ! #email `as` #userEmail)

153149 ( from (table (#users `as` #u)

154150 & innerJoin (table (#emails `as` #e))

@@ -158,22 +154,12 @@ let

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+314−129

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

@@ -16,10 +16,10 @@ Let's see some examples. We'll need some imports

1616>>> import Data.Int (Int16)

1717>>> import Data.Text (Text)

1818>>> import Control.Monad (void)

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

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

2020>>> import Squeal.PostgreSQL

2121

22−Define a Haskell datatype `Row` that will serve as both the input and output of a simple

22+Define a Haskell datatype @Row@ that will serve as both the input and output of a simple

2323round trip query.

2424

2525>>> data Row = Row { col1 :: Int16, col2 :: Text, col3 :: Maybe Bool } deriving (Eq, GHC.Generic)

@@ -27,7 +27,7 @@ round trip query.

2727>>> instance HasDatatypeInfo Row

2828>>> :{

2929let

30− roundTrip :: Query '[] (TuplePG Row) (RowPG Row)

30+ roundTrip :: Query_ (Public '[]) Row Row

3131 roundTrip = values_ $

3232 parameter @1 int2 `as` #col1 :*

3333 parameter @2 text `as` #col2 :*

@@ -39,15 +39,15 @@ the input and output should be equal.

3939

4040>>> let input = Row 2 "hi" (Just True)

4141>>> :{

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

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

4343 result <- runQueryParams roundTrip input

4444 Just output <- firstRow result

45− liftBase . print $ input == output

45+ liftIO . print $ input == output

4646:}

4747True

4848

4949In addition to being able to encode and decode basic Haskell types

50−like `Int16` and `Text`, Squeal permits you to encode and decode Haskell types to

50+like `Int16` and `Data.Text.Text`, Squeal permits you to encode and decode Haskell types to

5151Postgres array, enumerated and composite types and json. Let's see another example,

5252this time using the `Vector` type which corresponds to variable length arrays

5353and homogeneous tuples which correspond to fixed length arrays. We can even

@@ -55,9 +55,9 @@ create multi-dimensional fixed length arrays.

5555

5656>>> :{

5757data Row = Row

58− { col1 :: Vector Int16

59− , col2 :: (Maybe Int16,Maybe Int16)

60− , col3 :: ((Int16,Int16),(Int16,Int16),(Int16,Int16))

58+ { col1 :: VarArray (Vector Int16)

59+ , col2 :: FixArray (Maybe Int16,Maybe Int16)

60+ , col3 :: FixArray ((Int16,Int16),(Int16,Int16),(Int16,Int16))

6161 } deriving (Eq, GHC.Generic)

6262:}

6363

@@ -68,20 +68,20 @@ Once again, we define a simple round trip query.

6868

6969>>> :{

7070let

71− roundTrip :: Query '[] (TuplePG Row) (RowPG Row)

71+ roundTrip :: Query_ (Public '[]) Row Row

7272 roundTrip = values_ $

73− parameter @1 (int2 & vararray) `as` #col1 :*

74− parameter @2 (int2 & fixarray @2) `as` #col2 :*

75− parameter @3 (int2 & fixarray @2 & fixarray @3) `as` #col3

73+ parameter @1 (int2 & vararray) `as` #col1 :*

74+ parameter @2 (int2 & fixarray @'[2]) `as` #col2 :*

75+ parameter @3 (int2 & fixarray @'[3,2]) `as` #col3

7676:}

7777

7878>>> :set -XOverloadedLists

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

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

8080>>> :{

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

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

8282 result <- runQueryParams roundTrip input

8383 Just output <- firstRow result

84− liftBase . print $ input == output

84+ liftIO . print $ input == output

8585:}

8686True

8787

@@ -114,15 +114,15 @@ type Schema =

114114

115115>>> :{

116116let

117− setup :: Definition '[] Schema

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

118118 setup =

119119 createTypeEnumFrom @Schwarma #schwarma >>>

120120 createTypeCompositeFrom @Person #person

121121:}

122122

123−Let's demonstrate how to associate our Haskell types `Schwarma` and `Person`

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

124124with enumerated, composite or json types in Postgres. First create a Haskell

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

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

126126

127127>>> :{

128128data Row = Row

@@ -146,7 +146,7 @@ Once again, define a round trip query.

146146

147147>>> :{

148148let

149− roundTrip :: Query Schema (TuplePG Row) (RowPG Row)

149+ roundTrip :: Query_ (Public Schema) Row Row

150150 roundTrip = values_ $

151151 parameter @1 (typedef #schwarma) `as` #schwarma :*

152152 parameter @2 (typedef #person) `as` #person1 :*

@@ -157,7 +157,7 @@ Finally, we can drop our type definitions.

157157

158158>>> :{

159159let

160− teardown :: Definition Schema '[]

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

161161 teardown = dropType #schwarma >>> dropType #person

162162:}

163163

@@ -168,9 +168,9 @@ let

168168 session = do

169169 result <- runQueryParams roundTrip input

170170 Just output <- firstRow result

171− liftBase . print $ input == output

171+ liftIO . print $ input == output

172172in

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

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

174174 define setup

175175 & pqThen session

176176 & pqThen (define teardown)

@@ -194,20 +194,31 @@ True

194194 , MultiParamTypeClasses

195195 , ScopedTypeVariables

196196 , TypeApplications

197+ , TypeFamilies

197198 , TypeInType

198199 , TypeOperators

199200 , UndecidableInstances

201+ , UndecidableSuperClasses

200202#-}

201203

202204module Squeal.PostgreSQL.Binary

203205 ( -- * Encoding

204206 ToParam (..)

205207 , ToParams (..)

208+ , ToNullityParam (..)

209+ , ToField (..)

210+ , ToFixArray (..)

206211 -- * Decoding

207212 , FromValue (..)

208213 , FromRow (..)

214+ , FromField (..)

215+ , FromFixArray (..)

209216 -- * Only

210217 , Only (..)

218+ -- * Oid

219+ , OidOf (..)

220+ , OidOfParam (..)

221+ , OidOfField (..)

211222 ) where

212223

213224import BinaryParser

@@ -216,12 +227,12 @@ import Control.Arrow (left)

216227import Control.Monad

217228import Data.Int

218229import Data.Kind

219−import Data.Monoid hiding (All)

220230import Data.Scientific

221231import Data.Time

222232import Data.UUID.Types

223233import Data.Vector (Vector)

224234import Data.Word

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

225236import Generics.SOP

226237import Generics.SOP.Record

227238import GHC.TypeLits

@@ -235,10 +246,14 @@ import qualified Data.Text.Lazy as Lazy (Text)

235246import qualified Data.Text as Strict (Text)

236247import qualified Data.Text as Strict.Text

237248import qualified Data.Vector as Vector

249+import qualified Database.PostgreSQL.LibPQ as LibPQ

238250import qualified GHC.Generics as GHC

239251import qualified PostgreSQL.Binary.Decoding as Decoding

240252import qualified PostgreSQL.Binary.Encoding as Encoding

241253

254+import Squeal.PostgreSQL.Alias

255+import Squeal.PostgreSQL.List

256+import Squeal.PostgreSQL.PG

242257import Squeal.PostgreSQL.Schema

243258

244259-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into

@@ -262,14 +277,13 @@ class ToParam (x :: Type) (pg :: PGType) where

262277 toParam :: x -> K Encoding.Encoding pg

263278instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

264279instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

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

266280instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

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

268281instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

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

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

270283instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

271284instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

272285instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric

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

273287instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

274288instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

275289instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

@@ -298,16 +312,27 @@ instance Aeson.ToJSON x => ToParam (Json x) 'PGjson where

298312instance Aeson.ToJSON x => ToParam (Jsonb x) 'PGjsonb where

299313 toParam = K . Encoding.jsonb_bytes

300314 . Lazy.ByteString.toStrict . Aeson.encode . getJsonb

301−instance ToArray x ('NotNull ('PGvararray ty))

302− => ToParam x ('PGvararray ty) where

303− toParam

304− = K . Encoding.array (baseOid @x @('NotNull ('PGvararray ty)))

305− . unK . toArray @x @('NotNull ('PGvararray ty))

306−instance ToArray x ('NotNull ('PGfixarray n ty))

307− => ToParam x ('PGfixarray n ty) where

308− toParam

309− = K . Encoding.array (baseOid @x @('NotNull ('PGfixarray n ty)))

310− . unK . toArray @x @('NotNull ('PGfixarray n ty))

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

311336instance

312337 ( IsEnumType x

313338 , HasDatatypeInfo x

@@ -331,7 +356,7 @@ instance

331356 ( SListI fields

332357 , IsRecord x xs

333358 , AllZip ToField xs fields

334− , All HasAliasedOid fields

359+ , All OidOfField fields

335360 ) => ToParam (Composite x) ('PGcomposite fields) where

336361 toParam =

337362 let

@@ -339,7 +364,7 @@ instance

339364 encoders = htrans (Proxy @ToField) toField

340365

341366 composite

342− :: All HasAliasedOid row

367+ :: All OidOfField row

343368 => NP (K (Maybe Encoding.Encoding)) row

344369 -> K Encoding.Encoding ('PGcomposite row)

345370 composite fields = K $

@@ -356,27 +381,142 @@ instance

356381 int32BE (fromIntegral (lengthSList (Proxy @xs))) <>

357382 let

358383 each

359− :: HasAliasedOid field

384+ :: OidOfField field

360385 => K (Maybe Encoding.Encoding) field

361386 -> Encoding.Encoding

362387 each (K field :: K (Maybe Encoding.Encoding) field) =

363− word32BE (aliasedOid @field)

388+ word32BE (getOid (oidOfField @field))

364389 <> case field of

365390 Nothing -> int64BE (-1)

366391 Just value ->

367392 int32BE (fromIntegral (builderLength value))

368393 <> value

369394 in

370− hcfoldMap (Proxy @HasAliasedOid) each fields

395+ hcfoldMap (Proxy @OidOfField) each fields

371396

372397 in

373398 composite . encoders . toRecord . getComposite

374399

375−class HasAliasedOid (field :: (Symbol, NullityType)) where

376− aliasedOid :: Word32

377−instance HasOid ty => HasAliasedOid (alias ::: nullity ty) where

378− aliasedOid = oid @ty

379−

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`.

380520class ToNullityParam (x :: Type) (ty :: NullityType) where

381521 toNullityParam :: x -> K (Maybe Encoding.Encoding) ty

382522instance ToParam x pg => ToNullityParam x ('NotNull pg) where

@@ -384,55 +524,36 @@ instance ToParam x pg => ToNullityParam x ('NotNull pg) where

384524instance ToParam x pg => ToNullityParam (Maybe x) ('Null pg) where

385525 toNullityParam = K . fmap (unK . toParam @x @pg)

386526

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.

387531class ToField (x :: (Symbol, Type)) (field :: (Symbol, NullityType)) where

388532 toField :: P x -> K (Maybe Encoding.Encoding) field

389533instance ToNullityParam x ty => ToField (alias ::: x) (alias ::: ty) where

390534 toField (P x) = K . unK $ toNullityParam @x @ty x

391535

392−class ToArray (x :: Type) (array :: NullityType) where

393− toArray :: x -> K Encoding.Array array

394− baseOid :: Word32

395− default baseOid :: HasOid (PGTypeOf array) => Word32

396− baseOid = oid @(PGTypeOf array)

397−instance {-# OVERLAPPABLE #-} (HasOid pg, ToParam x pg)

398− => ToArray x ('NotNull pg) where

399− toArray = K . Encoding.encodingArray . unK . toParam @x @pg

400−instance {-# OVERLAPPABLE #-} (HasOid pg, ToParam x pg)

401− => ToArray (Maybe x) ('Null pg) where

402− toArray = K . maybe Encoding.nullArray

403− (Encoding.encodingArray . unK . toParam @x @pg)

404−instance {-# OVERLAPPING #-} ToArray x array

405− => ToArray (Vector x) ('NotNull ('PGvararray array)) where

406− toArray = K . Encoding.dimensionArray Vector.foldl'

407− (unK . toArray @x @array)

408− baseOid = baseOid @x @array

409−instance {-# OVERLAPPING #-} ToArray x array

410− => ToArray (Maybe (Vector x)) ('Null ('PGvararray array)) where

411− toArray = K . maybe Encoding.nullArray

412− (Encoding.dimensionArray Vector.foldl' (unK . toArray @x @array))

413− baseOid = baseOid @x @array

414−instance {-# OVERLAPPING #-}

415− ( IsProductType product xs

416− , Length xs ~ n

417− , All ((~) x) xs

418− , ToArray x array )

419− => ToArray product ('NotNull ('PGfixarray n array)) where

420− toArray = K . Encoding.dimensionArray foldlN

421− (unK . toArray @x @array) . unZ . unSOP . from

422− baseOid = baseOid @x @array

423−instance {-# OVERLAPPING #-}

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

424546 ( IsProductType product xs

425− , Length xs ~ n

547+ , Length xs ~ dim

426548 , All ((~) x) xs

427− , ToArray x array )

428− => ToArray (Maybe product) ('Null ('PGfixarray n array)) where

429− toArray = K . maybe Encoding.nullArray

430− (Encoding.dimensionArray foldlN (unK . toArray @x @array) . unZ . unSOP . from)

431− baseOid = baseOid @x @array

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

432553

433554-- | A `ToParams` constraint generically sequences the encodings of `Type`s

434555-- of the fields of a tuple or record to a row of `ColumnType`s. You should

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

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

436557-- which in turn provide `ToParams` instances.

437558class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

438559 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]

@@ -461,9 +582,11 @@ instance FromValue 'PGbool Bool where fromValue = Decoding.bool

461582instance FromValue 'PGint2 Int16 where fromValue = Decoding.int

462583instance FromValue 'PGint4 Int32 where fromValue = Decoding.int

463584instance FromValue 'PGint8 Int64 where fromValue = Decoding.int

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

464586instance FromValue 'PGfloat4 Float where fromValue = Decoding.float4

465587instance FromValue 'PGfloat8 Double where fromValue = Decoding.float8

466588instance FromValue 'PGnumeric Scientific where fromValue = Decoding.numeric

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

467590instance FromValue 'PGuuid UUID where fromValue = Decoding.uuid

468591instance FromValue 'PGinet (NetAddr IP) where fromValue = Decoding.inet

469592instance FromValue ('PGchar 1) Char where fromValue = Decoding.char

@@ -493,12 +616,41 @@ instance Aeson.FromJSON x => FromValue 'PGjson (Json x) where

493616instance Aeson.FromJSON x => FromValue 'PGjsonb (Jsonb x) where

494617 fromValue = Jsonb <$>

495618 Decoding.jsonb_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)

496−instance FromArray ('NotNull ('PGvararray ty)) y

497− => FromValue ('PGvararray ty) y where

498− fromValue = Decoding.array (fromArray @('NotNull ('PGvararray ty)) @y)

499−instance FromArray ('NotNull ('PGfixarray n ty)) y

500− => FromValue ('PGfixarray n ty) y where

501− fromValue = Decoding.array (fromArray @('NotNull ('PGfixarray n ty)) @y)

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)

502654instance

503655 ( IsEnumType y

504656 , HasDatatypeInfo y

@@ -569,49 +721,32 @@ instance FromValue pg y

569721 K (Just bytestring) -> P . Just <$>

570722 Decoding.valueParser (fromValue @pg) bytestring

571723

572−class FromArray (ty :: NullityType) (y :: Type) where

573− fromArray :: Decoding.Array y

574−instance {-# OVERLAPPABLE #-} FromValue pg y

575− => FromArray ('NotNull pg) y where

576− fromArray = Decoding.valueArray (fromValue @pg @y)

577−instance {-# OVERLAPPABLE #-} FromValue pg y

578− => FromArray ('Null pg) (Maybe y) where

579− fromArray = Decoding.nullableValueArray (fromValue @pg @y)

580−instance {-# OVERLAPPING #-} FromArray array y

581− => FromArray ('NotNull ('PGvararray array)) (Vector y) where

582− fromArray =

583− Decoding.dimensionArray Vector.replicateM (fromArray @array @y)

584−instance {-# OVERLAPPING #-} FromArray array y

585− => FromArray ('Null ('PGvararray array)) (Maybe (Vector y)) where

586− fromArray = Just <$>

587− Decoding.dimensionArray Vector.replicateM (fromArray @array @y)

588−instance {-# OVERLAPPING #-}

589− ( FromArray array y

590− , All ((~) y) ys

591− , SListI ys

592− , IsProductType product ys )

593− => FromArray ('NotNull ('PGfixarray n array)) product where

594− fromArray =

595− let

596− rep _ = fmap (to . SOP . Z) . replicateMN

597− in

598− Decoding.dimensionArray rep (fromArray @array @y)

599−instance {-# OVERLAPPING #-}

600− ( FromArray array y

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

601737 , All ((~) y) ys

602− , SListI ys

603− , IsProductType product ys )

604− => FromArray ('Null ('PGfixarray n array)) (Maybe product) where

605− fromArray =

738+ , FromFixArray dims ty y )

739+ => FromFixArray (dim ': dims) ty product where

740+ fromFixArray =

606741 let

607742 rep _ = fmap (to . SOP . Z) . replicateMN

608743 in

609− Just <$> Decoding.dimensionArray rep (fromArray @array @y)

744+ Decoding.dimensionArray rep (fromFixArray @dims @ty @y)

610745

611746-- | A `FromRow` constraint generically sequences the parsings of the columns

612747-- of a `RowType` into the fields of a record `Type` provided they have

613748-- the same field names. You should not define instances of `FromRow`.

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

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

615750-- provide `FromRow` instances.

616751class SListI result => FromRow (result :: RowType) y where

617752 -- | >>> :set -XOverloadedStrings

@@ -634,6 +769,53 @@ instance

634769 = fmap fromRecord

635770 . hsequence'

636771 . 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)

637819

638820-- | `Only` is a 1-tuple type, useful for encoding a single parameter with

639821-- `toParams` or decoding a single value with `fromRow`.

@@ -660,4 +842,7 @@ replicateMN

660842 :: forall x xs m. (All ((~) x) xs, Monad m, SListI xs)

661843 => m x -> m (NP I xs)

662844replicateMN mx = hsequence' $

663− hcpure (Proxy :: Proxy ((~) x)) (Comp (I <$> mx))

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+23−925

@@ -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

@@ -25,960 +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−type Table = '[] :=>

133− '[ "a" ::: 'NoDef :=> 'Null 'PGint4

134− , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]

135−:}

136−

137−>>> :{

138−let

139− setup :: Definition '[] '["tab" ::: 'Table Table]

140− setup = createTable #tab

141− (nullable int `as` #a :* nullable real `as` #b) Nil

142−in printSQL setup

143−:}

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

145−-}

146−createTable

147− :: ( KnownSymbol table

148− , columns ~ (col ': cols)

149− , SOP.SListI columns

150− , SOP.SListI constraints

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

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

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

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

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

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

157− -> Definition schema0 schema1

158−createTable tab columns constraints = UnsafeDefinition $

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

160−

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

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

163−`createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in

164−the `Category` of `Definition`s.

165−

166−>>> :set -XOverloadedLabels -XTypeApplications

167−>>> :{

168−type Table = '[] :=>

169− '[ "a" ::: 'NoDef :=> 'Null 'PGint4

170− , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]

171−:}

172−

173−>>> type Schema = '["tab" ::: 'Table Table]

174−

175−>>> :{

176−let

177− setup :: Definition Schema Schema

178− setup = createTableIfNotExists #tab

179− (nullable int `as` #a :* nullable real `as` #b) Nil

180−in printSQL setup

181−:}

182−CREATE TABLE IF NOT EXISTS "tab" ("a" int NULL, "b" real NULL);

183−-}

184−createTableIfNotExists

185− :: ( Has table schema ('Table (constraints :=> columns))

186− , SOP.SListI columns

187− , SOP.SListI constraints )

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

189− -> NP (Aliased (ColumnTypeExpression schema)) columns

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

191− -> NP (Aliased (TableConstraintExpression schema table)) constraints

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

193− -> Definition schema schema

194−createTableIfNotExists tab columns constraints = UnsafeDefinition $

195− "CREATE TABLE IF NOT EXISTS"

196− <+> renderCreation tab columns constraints

197−

198−-- helper function for `createTable` and `createTableIfNotExists`

199−renderCreation

200− :: ( KnownSymbol table

201− , SOP.SListI columns

202− , SOP.SListI constraints )

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

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

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

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

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

208− -> ByteString

209−renderCreation tab columns constraints = renderAlias tab

210− <+> parenthesized

211− ( renderCommaSeparated renderColumnDef columns

212− <> ( case constraints of

213− Nil -> ""

214− _ -> ", " <>

215− renderCommaSeparated renderConstraint constraints ) )

216− <> ";"

217− where

218− renderColumnDef :: Aliased (ColumnTypeExpression schema) x -> ByteString

219− renderColumnDef (ty `As` column) =

220− renderAlias column <+> renderColumnTypeExpression ty

221− renderConstraint

222− :: Aliased (TableConstraintExpression schema columns) constraint

223− -> ByteString

224− renderConstraint (constraint `As` alias) =

225− "CONSTRAINT" <+> renderAlias alias <+> renderTableConstraintExpression constraint

226−

227−-- | Data types are a way to limit the kind of data that can be stored in a

228−-- table. For many applications, however, the constraint they provide is

229−-- too coarse. For example, a column containing a product price should

230−-- probably only accept positive values. But there is no standard data type

231−-- that accepts only positive numbers. Another issue is that you might want

232−-- to constrain column data with respect to other columns or rows.

233−-- For example, in a table containing product information,

234−-- there should be only one row for each product number.

235−-- `TableConstraint`s give you as much control over the data in your tables

236−-- as you wish. If a user attempts to store data in a column that would

237−-- violate a constraint, an error is raised. This applies

238−-- even if the value came from the default value definition.

239−newtype TableConstraintExpression

240− (schema :: SchemaType)

241− (table :: Symbol)

242− (tableConstraint :: TableConstraint)

243− = UnsafeTableConstraintExpression

244− { renderTableConstraintExpression :: ByteString }

245− deriving (GHC.Generic,Show,Eq,Ord,NFData)

246−

247−{-| A `check` constraint is the most generic `TableConstraint` type.

248−It allows you to specify that the value in a certain column must satisfy

249−a Boolean (truth-value) expression.

250−

251−>>> :{

252−type Schema = '[

253− "tab" ::: 'Table ('[ "inequality" ::: 'Check '["a","b"]] :=> '[

254− "a" ::: 'NoDef :=> 'NotNull 'PGint4,

255− "b" ::: 'NoDef :=> 'NotNull 'PGint4

256− ])]

257−:}

258−

259−>>> :{

260−let

261− definition :: Definition '[] Schema

262− definition = createTable #tab

263− ( (int & notNullable) `as` #a :*

264− (int & notNullable) `as` #b )

265− ( check (#a :* #b) (#a .> #b) `as` #inequality )

266−:}

267−

268−>>> printSQL definition

269−CREATE TABLE "tab" ("a" int NOT NULL, "b" int NOT NULL, CONSTRAINT "inequality" CHECK (("a" > "b")));

270−-}

271−check

272− :: ( Has alias schema ('Table table)

273− , HasAll aliases (TableToRow table) subcolumns )

274− => NP Alias aliases

275− -- ^ specify the subcolumns which are getting checked

276− -> (forall tab. Condition schema '[tab ::: subcolumns] 'Ungrouped '[])

277− -- ^ a closed `Condition` on those subcolumns

278− -> TableConstraintExpression schema alias ('Check aliases)

279−check _cols condition = UnsafeTableConstraintExpression $

280− "CHECK" <+> parenthesized (renderExpression condition)

281−

282−{-| A `unique` constraint ensure that the data contained in a column,

283−or a group of columns, is unique among all the rows in the table.

284−

285−>>> :{

286−type Schema = '[

287− "tab" ::: 'Table( '[ "uq_a_b" ::: 'Unique '["a","b"]] :=> '[

288− "a" ::: 'NoDef :=> 'Null 'PGint4,

289− "b" ::: 'NoDef :=> 'Null 'PGint4

290− ])]

291−:}

292−

293−>>> :{

294−let

295− definition :: Definition '[] Schema

296− definition = createTable #tab

297− ( (int & nullable) `as` #a :*

298− (int & nullable) `as` #b )

299− ( unique (#a :* #b) `as` #uq_a_b )

300−:}

301−

302−>>> printSQL definition

303−CREATE TABLE "tab" ("a" int NULL, "b" int NULL, CONSTRAINT "uq_a_b" UNIQUE ("a", "b"));

304−-}

305−unique

306− :: ( Has alias schema ('Table table)

307− , HasAll aliases (TableToRow table) subcolumns )

308− => NP Alias aliases

309− -- ^ specify subcolumns which together are unique for each row

310− -> TableConstraintExpression schema alias ('Unique aliases)

311−unique columns = UnsafeTableConstraintExpression $

312− "UNIQUE" <+> parenthesized (commaSeparated (renderAliases columns))

313−

314−{-| A `primaryKey` constraint indicates that a column, or group of columns,

315−can be used as a unique identifier for rows in the table.

316−This requires that the values be both unique and not null.

317−

318−>>> :{

319−type Schema = '[

320− "tab" ::: 'Table ('[ "pk_id" ::: 'PrimaryKey '["id"]] :=> '[

321− "id" ::: 'Def :=> 'NotNull 'PGint4,

322− "name" ::: 'NoDef :=> 'NotNull 'PGtext

323− ])]

324−:}

325−

326−>>> :{

327−let

328− definition :: Definition '[] Schema

329− definition = createTable #tab

330− ( serial `as` #id :*

331− (text & notNullable) `as` #name )

332− ( primaryKey #id `as` #pk_id )

333−:}

334−

335−>>> printSQL definition

336−CREATE TABLE "tab" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_id" PRIMARY KEY ("id"));

337−-}

338−primaryKey

339− :: ( Has alias schema ('Table table)

340− , HasAll aliases (TableToColumns table) subcolumns

341− , AllNotNull subcolumns )

342− => NP Alias aliases

343− -- ^ specify the subcolumns which together form a primary key.

344− -> TableConstraintExpression schema alias ('PrimaryKey aliases)

345−primaryKey columns = UnsafeTableConstraintExpression $

346− "PRIMARY KEY" <+> parenthesized (commaSeparated (renderAliases columns))

347−

348−{-| A `foreignKey` specifies that the values in a column

349−(or a group of columns) must match the values appearing in some row of

350−another table. We say this maintains the referential integrity

351−between two related tables.

352−

353−>>> :{

354−type Schema =

355− '[ "users" ::: 'Table (

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

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

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

359− ])

360− , "emails" ::: 'Table (

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

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

363− ] :=>

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

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

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

367− ])

368− ]

369−:}

370−

371−>>> :{

372−let

373− setup :: Definition '[] Schema

374− setup =

375− createTable #users

376− ( serial `as` #id :*

377− (text & notNullable) `as` #name )

378− ( primaryKey #id `as` #pk_users ) >>>

379− createTable #emails

380− ( serial `as` #id :*

381− (int & notNullable) `as` #user_id :*

382− (text & nullable) `as` #email )

383− ( primaryKey #id `as` #pk_emails :*

384− foreignKey #user_id #users #id

385− OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

386−in printSQL setup

387−:}

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

389−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);

390−

391−A `foreignKey` can even be a table self-reference.

392−

393−>>> :{

394−type Schema =

395− '[ "employees" ::: 'Table (

396− '[ "employees_pk" ::: 'PrimaryKey '["id"]

397− , "employees_employer_fk" ::: 'ForeignKey '["employer_id"] "employees" '["id"]

398− ] :=>

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

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

401− , "employer_id" ::: 'NoDef :=> 'Null 'PGint4

402− ])

403− ]

404−:}

405−

406−>>> :{

407−let

408− setup :: Definition '[] Schema

409− setup =

410− createTable #employees

411− ( serial `as` #id :*

412− (text & notNullable) `as` #name :*

413− (integer & nullable) `as` #employer_id )

414− ( primaryKey #id `as` #employees_pk :*

415− foreignKey #employer_id #employees #id

416− OnDeleteCascade OnUpdateCascade `as` #employees_employer_fk )

417−in printSQL setup

418−:}

419−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);

420−-}

421−foreignKey

422− :: (ForeignKeyed schema child parent

423− table reftable

424− columns refcolumns

425− constraints cols

426− reftys tys )

427− => NP Alias columns

428− -- ^ column or columns in the table

429− -> Alias parent

430− -- ^ reference table

431− -> NP Alias refcolumns

432− -- ^ reference column or columns in the reference table

433− -> OnDeleteClause

434− -- ^ what to do when reference is deleted

435− -> OnUpdateClause

436− -- ^ what to do when reference is updated

437− -> TableConstraintExpression schema child

438− ('ForeignKey columns parent refcolumns)

439−foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $

440− "FOREIGN KEY" <+> parenthesized (commaSeparated (renderAliases keys))

441− <+> "REFERENCES" <+> renderAlias parent

442− <+> parenthesized (commaSeparated (renderAliases refs))

443− <+> renderOnDeleteClause ondel

444− <+> renderOnUpdateClause onupd

445−

446−-- | A constraint synonym between types involved in a foreign key constraint.

447−type ForeignKeyed schema

448− child parent

449− table reftable

450− columns refcolumns

451− constraints cols

452− reftys tys =

453− ( Has child schema ('Table table)

454− , Has parent schema ('Table reftable)

455− , HasAll columns (TableToColumns table) tys

456− , reftable ~ (constraints :=> cols)

457− , HasAll refcolumns cols reftys

458− , SOP.AllZip SamePGType tys reftys

459− , Uniquely refcolumns constraints )

460−

461−-- | `OnDeleteClause` indicates what to do with rows that reference a deleted row.

462−data OnDeleteClause

463− = OnDeleteNoAction

464− -- ^ if any referencing rows still exist when the constraint is checked,

465− -- an error is raised

466− | OnDeleteRestrict -- ^ prevents deletion of a referenced row

467− | OnDeleteCascade

468− -- ^ specifies that when a referenced row is deleted,

469− -- row(s) referencing it should be automatically deleted as well

470− deriving (GHC.Generic,Show,Eq,Ord)

471−instance NFData OnDeleteClause

472−

473−-- | Render `OnDeleteClause`.

474−renderOnDeleteClause :: OnDeleteClause -> ByteString

475−renderOnDeleteClause = \case

476− OnDeleteNoAction -> "ON DELETE NO ACTION"

477− OnDeleteRestrict -> "ON DELETE RESTRICT"

478− OnDeleteCascade -> "ON DELETE CASCADE"

479−

480−-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked

481−-- when a referenced column is changed (updated).

482−data OnUpdateClause

483− = OnUpdateNoAction

484− -- ^ if any referencing rows has not changed when the constraint is checked,

485− -- an error is raised

486− | OnUpdateRestrict -- ^ prevents update of a referenced row

487− | OnUpdateCascade

488− -- ^ the updated values of the referenced column(s) should be copied

489− -- into the referencing row(s)

490− deriving (GHC.Generic,Show,Eq,Ord)

491−instance NFData OnUpdateClause

492−

493−-- | Render `OnUpdateClause`.

494−renderOnUpdateClause :: OnUpdateClause -> ByteString

495−renderOnUpdateClause = \case

496− OnUpdateNoAction -> "ON UPDATE NO ACTION"

497− OnUpdateRestrict -> "ON UPDATE RESTRICT"

498− OnUpdateCascade -> "ON UPDATE CASCADE"

499−

500−{-----------------------------------------

501−DROP statements

502−-----------------------------------------}

503−

504−-- | `dropTable` removes a table from the schema.

505−--

506−-- >>> :{

507−-- let

508−-- definition :: Definition '["muh_table" ::: 'Table t] '[]

509−-- definition = dropTable #muh_table

510−-- :}

511−--

512−-- >>> printSQL definition

513−-- DROP TABLE "muh_table";

514−dropTable

515− :: Has table schema ('Table t)

516− => Alias table -- ^ table to remove

517− -> Definition schema (Drop table schema)

518−dropTable tab = UnsafeDefinition $ "DROP TABLE" <+> renderAlias tab <> ";"

519−

520−{-----------------------------------------

521−ALTER statements

522−-----------------------------------------}

523−

524−-- | `alterTable` changes the definition of a table from the schema.

525−alterTable

526− :: KnownSymbol alias

527− => Alias alias -- ^ table to alter

528− -> AlterTable alias table schema -- ^ alteration to perform

529− -> Definition schema (Alter alias ('Table table) schema)

530−alterTable tab alteration = UnsafeDefinition $

531− "ALTER TABLE"

532− <+> renderAlias tab

533− <+> renderAlterTable alteration

534− <> ";"

535−

536−-- | `alterTableRename` changes the name of a table from the schema.

537−--

538−-- >>> printSQL $ alterTableRename #foo #bar

539−-- ALTER TABLE "foo" RENAME TO "bar";

540−alterTableRename

541− :: (KnownSymbol table0, KnownSymbol table1)

542− => Alias table0 -- ^ table to rename

543− -> Alias table1 -- ^ what to rename it

544− -> Definition schema (Rename table0 table1 schema)

545−alterTableRename table0 table1 = UnsafeDefinition $

546− "ALTER TABLE" <+> renderAlias table0

547− <+> "RENAME TO" <+> renderAlias table1 <> ";"

548−

549−-- | An `AlterTable` describes the alteration to perform on the columns

550−-- of a table.

551−newtype AlterTable

552− (alias :: Symbol)

553− (table :: TableType)

554− (schema :: SchemaType) =

555− UnsafeAlterTable {renderAlterTable :: ByteString}

556− deriving (GHC.Generic,Show,Eq,Ord,NFData)

557−

558−-- | An `addConstraint` adds a table constraint.

559−--

560−-- >>> :{

561−-- let

562−-- definition :: Definition

563−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

564−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

565−-- definition = alterTable #tab (addConstraint #positive (check #col (#col .> 0)))

566−-- in printSQL definition

567−-- :}

568−-- ALTER TABLE "tab" ADD CONSTRAINT "positive" CHECK (("col" > 0));

569−addConstraint

570− :: ( KnownSymbol alias

571− , Has tab schema ('Table table0)

572− , table0 ~ (constraints :=> columns)

573− , table1 ~ (Create alias constraint constraints :=> columns) )

574− => Alias alias

575− -> TableConstraintExpression schema tab constraint

576− -- ^ constraint to add

577− -> AlterTable tab table1 schema

578−addConstraint alias constraint = UnsafeAlterTable $

579− "ADD" <+> "CONSTRAINT" <+> renderAlias alias

580− <+> renderTableConstraintExpression constraint

581−

582−-- | A `dropConstraint` drops a table constraint.

583−--

584−-- >>> :{

585−-- let

586−-- definition :: Definition

587−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

588−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

589−-- definition = alterTable #tab (dropConstraint #positive)

590−-- in printSQL definition

591−-- :}

592−-- ALTER TABLE "tab" DROP CONSTRAINT "positive";

593−dropConstraint

594− :: ( KnownSymbol constraint

595− , Has tab schema ('Table table0)

596− , table0 ~ (constraints :=> columns)

597− , table1 ~ (Drop constraint constraints :=> columns) )

598− => Alias constraint

599− -- ^ constraint to drop

600− -> AlterTable tab table1 schema

601−dropConstraint constraint = UnsafeAlterTable $

602− "DROP" <+> "CONSTRAINT" <+> renderAlias constraint

603−

604−-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.

605−class AddColumn ty where

606− -- | `addColumn` adds a new column, initially filled with whatever

607− -- default value is given or with @NULL@.

608− --

609− -- >>> :{

610− -- let

611− -- definition :: Definition

612− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

613− -- '["tab" ::: 'Table ('[] :=>

614− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

615− -- , "col2" ::: 'Def :=> 'Null 'PGtext ])]

616− -- definition = alterTable #tab (addColumn #col2 (text & nullable & default_ "foo"))

617− -- in printSQL definition

618− -- :}

619− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL DEFAULT E'foo';

620− --

621− -- >>> :{

622− -- let

623− -- definition :: Definition

624− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

625− -- '["tab" ::: 'Table ('[] :=>

626− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

627− -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]

628− -- definition = alterTable #tab (addColumn #col2 (text & nullable))

629− -- in printSQL definition

630− -- :}

631− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL;

632− addColumn

633− :: ( KnownSymbol column

634− , Has tab schema ('Table table0)

635− , table0 ~ (constraints :=> columns)

636− , table1 ~ (constraints :=> Create column ty columns) )

637− => Alias column -- ^ column to add

638− -> ColumnTypeExpression schema ty -- ^ type of the new column

639− -> AlterTable tab table1 schema

640− addColumn column ty = UnsafeAlterTable $

641− "ADD COLUMN" <+> renderAlias column <+> renderColumnTypeExpression ty

642−instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)

643−instance {-# OVERLAPPABLE #-} AddColumn ('NoDef :=> 'Null ty)

644−

645−-- | A `dropColumn` removes a column. Whatever data was in the column

646−-- disappears. Table constraints involving the column are dropped, too.

647−-- However, if the column is referenced by a foreign key constraint of

648−-- another table, PostgreSQL will not silently drop that constraint.

649−--

650−-- >>> :{

651−-- let

652−-- definition :: Definition

653−-- '["tab" ::: 'Table ('[] :=>

654−-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

655−-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]

656−-- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

657−-- definition = alterTable #tab (dropColumn #col2)

658−-- in printSQL definition

659−-- :}

660−-- ALTER TABLE "tab" DROP COLUMN "col2";

661−dropColumn

662− :: ( KnownSymbol column

663− , Has tab schema ('Table table0)

664− , table0 ~ (constraints :=> columns)

665− , table1 ~ (constraints :=> Drop column columns) )

666− => Alias column -- ^ column to remove

667− -> AlterTable tab table1 schema

668−dropColumn column = UnsafeAlterTable $

669− "DROP COLUMN" <+> renderAlias column

670−

671−-- | A `renameColumn` renames a column.

672−--

673−-- >>> :{

674−-- let

675−-- definition :: Definition

676−-- '["tab" ::: 'Table ('[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4])]

677−-- '["tab" ::: 'Table ('[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4])]

678−-- definition = alterTable #tab (renameColumn #foo #bar)

679−-- in printSQL definition

680−-- :}

681−-- ALTER TABLE "tab" RENAME COLUMN "foo" TO "bar";

682−renameColumn

683− :: ( KnownSymbol column0

684− , KnownSymbol column1

685− , Has tab schema ('Table table0)

686− , table0 ~ (constraints :=> columns)

687− , table1 ~ (constraints :=> Rename column0 column1 columns) )

688− => Alias column0 -- ^ column to rename

689− -> Alias column1 -- ^ what to rename the column

690− -> AlterTable tab table1 schema

691−renameColumn column0 column1 = UnsafeAlterTable $

692− "RENAME COLUMN" <+> renderAlias column0 <+> "TO" <+> renderAlias column1

693−

694−-- | An `alterColumn` alters a single column.

695−alterColumn

696− :: ( KnownSymbol column

697− , Has tab schema ('Table table0)

698− , table0 ~ (constraints :=> columns)

699− , Has column columns ty0

700− , tables1 ~ (constraints :=> Alter column ty1 columns))

701− => Alias column -- ^ column to alter

702− -> AlterColumn schema ty0 ty1 -- ^ alteration to perform

703− -> AlterTable tab table1 schema

704−alterColumn column alteration = UnsafeAlterTable $

705− "ALTER COLUMN" <+> renderAlias column <+> renderAlterColumn alteration

706−

707−-- | An `AlterColumn` describes the alteration to perform on a single column.

708−newtype AlterColumn (schema :: SchemaType) (ty0 :: ColumnType) (ty1 :: ColumnType) =

709− UnsafeAlterColumn {renderAlterColumn :: ByteString}

710− deriving (GHC.Generic,Show,Eq,Ord,NFData)

711−

712−-- | A `setDefault` sets a new default for a column. Note that this doesn't

713−-- affect any existing rows in the table, it just changes the default for

714−-- future insert and update commands.

715−--

716−-- >>> :{

717−-- let

718−-- definition :: Definition

719−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

720−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

721−-- definition = alterTable #tab (alterColumn #col (setDefault 5))

722−-- in printSQL definition

723−-- :}

724−-- ALTER TABLE "tab" ALTER COLUMN "col" SET DEFAULT 5;

725−setDefault

726− :: Expression schema '[] 'Ungrouped '[] ty -- ^ default value to set

727− -> AlterColumn schema (constraint :=> ty) ('Def :=> ty)

728−setDefault expression = UnsafeAlterColumn $

729− "SET DEFAULT" <+> renderExpression expression

730−

731−-- | A `dropDefault` removes any default value for a column.

732−--

733−-- >>> :{

734−-- let

735−-- definition :: Definition

736−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

737−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

738−-- definition = alterTable #tab (alterColumn #col dropDefault)

739−-- in printSQL definition

740−-- :}

741−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP DEFAULT;

742−dropDefault :: AlterColumn schema ('Def :=> ty) ('NoDef :=> ty)

743−dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"

744−

745−-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.

746−-- The constraint will be checked immediately, so the table data must satisfy

747−-- the constraint before it can be added.

748−--

749−-- >>> :{

750−-- let

751−-- definition :: Definition

752−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

753−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

754−-- definition = alterTable #tab (alterColumn #col setNotNull)

755−-- in printSQL definition

756−-- :}

757−-- ALTER TABLE "tab" ALTER COLUMN "col" SET NOT NULL;

758−setNotNull

759− :: AlterColumn schema (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)

760−setNotNull = UnsafeAlterColumn $ "SET NOT NULL"

761−

762−-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.

763−--

764−-- >>> :{

765−-- let

766−-- definition :: Definition

767−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

768−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

769−-- definition = alterTable #tab (alterColumn #col dropNotNull)

770−-- in printSQL definition

771−-- :}

772−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP NOT NULL;

773−dropNotNull

774− :: AlterColumn schema (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)

775−dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"

776−

777−-- | An `alterType` converts a column to a different data type.

778−-- This will succeed only if each existing entry in the column can be

779−-- converted to the new type by an implicit cast.

780−--

781−-- >>> :{

782−-- let

783−-- definition :: Definition

784−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

785−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]

786−-- definition =

787−-- alterTable #tab (alterColumn #col (alterType (numeric & notNullable)))

788−-- in printSQL definition

789−-- :}

790−-- ALTER TABLE "tab" ALTER COLUMN "col" TYPE numeric NOT NULL;

791−alterType :: ColumnTypeExpression schema ty -> AlterColumn schema ty0 ty

792−alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty

793−

794−-- | Create a view.

795−--

796−-- >>> :{

797−-- let

798−-- definition :: Definition

799−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]

800−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

801−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]

802−-- definition =

803−-- createView #bc (select (#b :* #c) (from (table #abc)))

804−-- in printSQL definition

805−-- :}

806−-- CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";

807−createView

808− :: KnownSymbol view

809− => Alias view -- ^ the name of the view to add

810− -> Query schema '[] row

811− -- ^ query

812− -> Definition schema (Create view ('View row) schema)

813−createView alias query = UnsafeDefinition $

814− "CREATE" <+> "VIEW" <+> renderAlias alias <+> "AS"

815− <+> renderQuery query <> ";"

816−

817−-- | Drop a view.

818−--

819−-- >>> :{

820−-- let

821−-- definition :: Definition

822−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

823−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]

824−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]

825−-- definition = dropView #bc

826−-- in printSQL definition

827−-- :}

828−-- DROP VIEW "bc";

829−dropView

830− :: Has view schema ('View v)

831− => Alias view -- ^ view to remove

832− -> Definition schema (Drop view schema)

833−dropView v = UnsafeDefinition $ "DROP VIEW" <+> renderAlias v <> ";"

834−

835−-- | Enumerated types are created using the `createTypeEnum` command, for example

836−--

837−-- >>> printSQL $ createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy")

838−-- CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');

839−createTypeEnum

840− :: (KnownSymbol enum, SOP.All KnownSymbol labels)

841− => Alias enum

842− -- ^ name of the user defined enumerated type

843− -> NP PGlabel labels

844− -- ^ labels of the enumerated type

845− -> Definition schema (Create enum ('Typedef ('PGenum labels)) schema)

846−createTypeEnum enum labels = UnsafeDefinition $

847− "CREATE" <+> "TYPE" <+> renderAlias enum <+> "AS" <+> "ENUM" <+>

848− parenthesized (commaSeparated (renderLabels labels)) <> ";"

849−

850−-- | Enumerated types can also be generated from a Haskell type, for example

851−--

852−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

853−-- >>> instance SOP.Generic Schwarma

854−-- >>> instance SOP.HasDatatypeInfo Schwarma

855−-- >>> printSQL $ createTypeEnumFrom @Schwarma #schwarma

856−-- CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');

857−createTypeEnumFrom

858− :: forall hask enum schema.

859− ( SOP.Generic hask

860− , SOP.All KnownSymbol (LabelsPG hask)

861− , KnownSymbol enum

862− )

863− => Alias enum

864− -- ^ name of the user defined enumerated type

865− -> Definition schema (Create enum ('Typedef (PG (Enumerated hask))) schema)

866−createTypeEnumFrom enum = createTypeEnum enum

867− (SOP.hpure label :: NP PGlabel (LabelsPG hask))

868−

869−{- | `createTypeComposite` creates a composite type. The composite type is

870−specified by a list of attribute names and data types.

871−

872−>>> :{

873−type PGcomplex = 'PGcomposite

874− '[ "real" ::: 'NotNull 'PGfloat8

875− , "imaginary" ::: 'NotNull 'PGfloat8 ]

876−:}

877−

878−>>> :{

879−let

880− setup :: Definition '[] '["complex" ::: 'Typedef PGcomplex]

881− setup = createTypeComposite #complex

882− (float8 `as` #real :* float8 `as` #imaginary)

883−in printSQL setup

884−:}

885−CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

886−-}

887−createTypeComposite

888− :: (KnownSymbol ty, SOP.SListI fields)

889− => Alias ty

890− -- ^ name of the user defined composite type

891− -> NP (Aliased (TypeExpression schema)) fields

892− -- ^ list of attribute names and data types

893− -> Definition schema (Create ty ('Typedef ('PGcomposite fields)) schema)

894−createTypeComposite ty fields = UnsafeDefinition $

895− "CREATE" <+> "TYPE" <+> renderAlias ty <+> "AS" <+> parenthesized

896− (renderCommaSeparated renderField fields) <> ";"

897− where

898− renderField :: Aliased (TypeExpression schema) x -> ByteString

899− renderField (typ `As` alias) =

900− renderAlias alias <+> renderTypeExpression typ

901−

902−-- | Composite types can also be generated from a Haskell type, for example

903−--

904−-- >>> data Complex = Complex {real :: Double, imaginary :: Double} deriving GHC.Generic

905−-- >>> instance SOP.Generic Complex

906−-- >>> instance SOP.HasDatatypeInfo Complex

907−-- >>> printSQL $ createTypeCompositeFrom @Complex #complex

908−-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

909−createTypeCompositeFrom

910− :: forall hask ty schema.

911− ( SOP.All (FieldTyped schema) (RowPG hask)

912− , KnownSymbol ty )

913− => Alias ty

914− -- ^ name of the user defined composite type

915− -> Definition schema (Create ty ( 'Typedef (PG (Composite hask))) schema)

916−createTypeCompositeFrom ty = createTypeComposite ty

917− (SOP.hcpure (SOP.Proxy :: SOP.Proxy (FieldTyped schema)) fieldtype

918− :: NP (Aliased (TypeExpression schema)) (RowPG hask))

919−

920−class FieldTyped schema ty where

921− fieldtype :: Aliased (TypeExpression schema) ty

922−instance (KnownSymbol alias, PGTyped schema ty)

923− => FieldTyped schema (alias ::: ty) where

924− fieldtype = pgtype `As` Alias

925−

926−-- | Drop a type.

927−--

928−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

929−-- >>> instance SOP.Generic Schwarma

930−-- >>> instance SOP.HasDatatypeInfo Schwarma

931−-- >>> printSQL (dropType #schwarma :: Definition '["schwarma" ::: 'Typedef (PG (Enumerated Schwarma))] '[])

932−-- DROP TYPE "schwarma";

933−dropType

934− :: Has tydef schema ('Typedef ty)

935− => Alias tydef

936− -- ^ name of the user defined type

937− -> Definition schema (Drop tydef schema)

938−dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderAlias tydef <> ";"

939−

940−-- | `ColumnTypeExpression`s are used in `createTable` commands.

941−newtype ColumnTypeExpression (schema :: SchemaType) (ty :: ColumnType)

942− = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }

943− deriving (GHC.Generic,Show,Eq,Ord,NFData)

944−

945−-- | used in `createTable` commands as a column constraint to note that

946−-- @NULL@ may be present in a column

947−nullable

948− :: TypeExpression schema (nullity ty)

949− -> ColumnTypeExpression schema ('NoDef :=> 'Null ty)

950−nullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NULL"

951−

952−-- | used in `createTable` commands as a column constraint to ensure

953−-- @NULL@ is not present in a column

954−notNullable

955− :: TypeExpression schema (nullity ty)

956− -> ColumnTypeExpression schema ('NoDef :=> 'NotNull ty)

957−notNullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NOT NULL"

958−

959−-- | used in `createTable` commands as a column constraint to give a default

960−default_

961− :: Expression schema '[] 'Ungrouped '[] ty

962− -> ColumnTypeExpression schema ('NoDef :=> ty)

963− -> ColumnTypeExpression schema ('Def :=> ty)

964−default_ x ty = UnsafeColumnTypeExpression $

965− renderColumnTypeExpression ty <+> "DEFAULT" <+> renderExpression x

966−

967−-- | not a true type, but merely a notational convenience for creating

968−-- unique identifier columns with type `PGint2`

969−serial2, smallserial

970− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint2)

971−serial2 = UnsafeColumnTypeExpression "serial2"

972−smallserial = UnsafeColumnTypeExpression "smallserial"

973−-- | not a true type, but merely a notational convenience for creating

974−-- unique identifier columns with type `PGint4`

975−serial4, serial

976− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint4)

977−serial4 = UnsafeColumnTypeExpression "serial4"

978−serial = UnsafeColumnTypeExpression "serial"

979−-- | not a true type, but merely a notational convenience for creating

980−-- unique identifier columns with type `PGint8`

981−serial8, bigserial

982− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint8)

983−serial8 = UnsafeColumnTypeExpression "serial8"

984−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+336−1622

@@ -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

@@ -16,11 +15,13 @@ 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

@@ -31,543 +32,351 @@ Squeal expressions are the atoms used to build statements.

3132

3233module Squeal.PostgreSQL.Expression

3334 ( -- * Expression

34− Expression (UnsafeExpression, renderExpression)

35− , HasParameter (parameter)

36− , param

37− -- ** Null

38− , null_

39− , notNull

40− , coalesce

41− , fromNull

42− , isNull

43− , isNotNull

44− , matchNull

45− , nullIf

46− -- ** Collections

47− , array

48− , index

49− , row

50− , field

51− -- ** Functions

52− , unsafeBinaryOp

53− , unsafeUnaryOp

35+ Expression (..)

36+ , Expr

37+ , type (-->)

38+ , FunctionDB

5439 , unsafeFunction

55− , unsafeVariadicFunction

56− , atan2_

57− , cast

58− , quot_

59− , rem_

60− , trunc

61− , round_

62− , ceiling_

63− , greatest

64− , least

65− -- ** Conditions

66− , true

67− , false

68− , not_

69− , (.&&)

70− , (.||)

71− , Condition

72− , caseWhenThenElse

73− , ifThenElse

74− , (.==)

75− , (./=)

76− , (.>=)

77− , (.<)

78− , (.<=)

79− , (.>)

80− -- ** Time

81− , currentDate

82− , currentTime

83− , currentTimestamp

84− , localTime

85− , localTimestamp

86− -- ** Text

87− , lower

88− , upper

89− , charLength

90− , like

91− -- ** Json

92− -- *** Json and Jsonb operators

93− , (.->)

94− , (.->>)

95− , (.#>)

96− , (.#>>)

97− -- *** Jsonb operators

98− , (.@>)

99− , (.<@)

100− , (.?)

101− , (.?|)

102− , (.?&)

103− , (.-.)

104− , (#-.)

105− -- *** Functions

106− , jsonLit

107− , jsonbLit

108− , toJson

109− , toJsonb

110− , arrayToJson

111− , rowToJson

112− , jsonBuildArray

113− , jsonbBuildArray

114− , jsonBuildObject

115− , jsonbBuildObject

116− , jsonObject

117− , jsonbObject

118− , jsonZipObject

119− , jsonbZipObject

120− , jsonArrayLength

121− , jsonbArrayLength

122− , jsonExtractPath

123− , jsonbExtractPath

124− , jsonExtractPathAsText

125− , jsonbExtractPathAsText

126− , jsonTypeof

127− , jsonbTypeof

128− , jsonStripNulls

129− , jsonbStripNulls

130− , jsonbSet

131− , jsonbInsert

132− , jsonbPretty

133− -- ** Aggregation

134− , unsafeAggregate, unsafeAggregateDistinct

135− , sum_, sumDistinct

136− , PGAvg (avg, avgDistinct)

137− , bitAnd, bitOr, boolAnd, boolOr

138− , bitAndDistinct, bitOrDistinct, boolAndDistinct, boolOrDistinct

139− , countStar

140− , count, countDistinct

141− , every, everyDistinct

142− , max_, maxDistinct, min_, minDistinct

143− -- * Types

144− , TypeExpression (UnsafeTypeExpression, renderTypeExpression)

145− , PGTyped (pgtype)

146− , typedef

147− , typetable

148− , typeview

149− , bool

150− , int2

151− , smallint

152− , int4

153− , int

154− , integer

155− , int8

156− , bigint

157− , numeric

158− , float4

159− , real

160− , float8

161− , doublePrecision

162− , text

163− , char

164− , character

165− , varchar

166− , characterVarying

167− , bytea

168− , timestamp

169− , timestampWithTimeZone

170− , date

171− , time

172− , timeWithTimeZone

173− , interval

174− , uuid

175− , inet

176− , json

177− , jsonb

178− , vararray

179− , 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 (..)

18057 -- * Re-export

18158 , (&)

182− , NP ((:*), Nil)

59+ , K (..)

60+ , unK

18361 ) where

18462

18563import Control.Category

18664import Control.DeepSeq

18765import Data.ByteString (ByteString)

188−import Data.ByteString.Lazy (toStrict)

18966import Data.Function ((&))

19067import Data.Semigroup hiding (All)

191−import qualified Data.Aeson as JSON

192−import Data.Ratio

19368import Data.String

194−import Data.Word

195−import Generics.SOP hiding (from)

69+import Generics.SOP hiding (All, from)

19670import GHC.OverloadedLabels

19771import GHC.TypeLits

72+import Numeric

19873import Prelude hiding (id, (.))

19974

20075import qualified GHC.Generics as GHC

20176

77+import Squeal.PostgreSQL.Alias

78+import Squeal.PostgreSQL.List

20279import Squeal.PostgreSQL.Render

20380import Squeal.PostgreSQL.Schema

20481

82+-- $setup

83+-- >>> import Squeal.PostgreSQL

84+

20585{-----------------------------------------

20686column expressions

20787-----------------------------------------}

20888

20989{- | `Expression`s are used in a variety of contexts,

210−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,

21192as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or

21293`Squeal.PostgreSQL.Manipulation.update`,

213−or in search `Condition`s in a number of commands.

94+or in search `Squeal.PostgreSQL.Logic.Condition`s in a number of commands.

21495

21596The expression syntax allows the calculation of

21697values from primitive expression using arithmetic, logical,

21798and 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`.

218113-}

219114newtype Expression

220− (schema :: SchemaType)

221− (from :: FromType)

222− (grouping :: Grouping)

115+ (outer :: FromType)

116+ (commons :: FromType)

117+ (grp :: Grouping)

118+ (schemas :: SchemasType)

223119 (params :: [NullityType])

120+ (from :: FromType)

224121 (ty :: NullityType)

225122 = UnsafeExpression { renderExpression :: ByteString }

226123 deriving (GHC.Generic,Show,Eq,Ord,NFData)

227−

228−instance RenderSQL (Expression schema from grouping params ty) where

124+instance RenderSQL (Expression outer commons grp schemas params from ty) where

229125 renderSQL = renderExpression

230126

231−{- | A `HasParameter` constraint is used to indicate a value that is

232−supplied externally to a SQL statement.

233−`Squeal.PostgreSQL.PQ.manipulateParams`,

234−`Squeal.PostgreSQL.PQ.queryParams` and

235−`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values

236−separately from the SQL command string, in which case `param`s are used to

237−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)

238181-}

239−class KnownNat n => HasParameter

240− (n :: Nat)

241− (schema :: SchemaType)

242− (params :: [NullityType])

243− (ty :: NullityType)

244− | n params -> ty where

245− -- | `parameter` takes a `Nat` using type application and a `TypeExpression`.

246− --

247− -- >>> let expr = parameter @1 int4 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)

248− -- >>> printSQL expr

249− -- ($1 :: int4)

250− parameter

251− :: TypeExpression schema ty

252− -> Expression schema from grouping params ty

253− parameter ty = UnsafeExpression $ parenthesized $

254− "$" <> renderNat @n <+> "::"

255− <+> renderTypeExpression ty

256−instance {-# OVERLAPPING #-} HasParameter 1 schema (ty1:tys) ty1

257−instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) schema params ty)

258− => HasParameter n schema (ty' : params) ty

259−

260−-- | `param` takes a `Nat` using type application and for basic types,

261−-- infers a `TypeExpression`.

262−--

263−-- >>> let expr = param @1 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)

264−-- >>> printSQL expr

265−-- ($1 :: int4)

266−param

267− :: forall n schema params from grouping ty

268− . (PGTyped schema ty, HasParameter n schema params ty)

269− => Expression schema from grouping params ty -- ^ param

270−param = parameter @n pgtype

271−

272−instance (HasUnique table from columns, Has column columns ty)

273− => IsLabel column (Expression schema from 'Ungrouped params ty) where

274− fromLabel = UnsafeExpression $ renderAlias (Alias @column)

275−instance (HasUnique table from columns, Has column columns ty)

276− => IsLabel column

277− (Aliased (Expression schema from 'Ungrouped params) (column ::: ty)) where

278− fromLabel = fromLabel @column `As` Alias @column

279−instance (HasUnique table from columns, Has column columns ty)

280− => IsLabel column

281− (NP (Aliased (Expression schema from 'Ungrouped params)) '[column ::: ty]) where

282− fromLabel = fromLabel @column :* Nil

283−

284−instance (Has table from columns, Has column columns ty)

285− => IsQualified table column (Expression schema from 'Ungrouped params ty) where

286− table ! column = UnsafeExpression $

287− renderAlias table <> "." <> renderAlias column

288−instance (Has table from columns, Has column columns ty)

289− => IsQualified table column

290− (Aliased (Expression schema from 'Ungrouped params) (column ::: ty)) where

291− table ! column = table ! column `As` column

292−instance (Has table from columns, Has column columns ty)

293− => IsQualified table column

294− (NP (Aliased (Expression schema from 'Ungrouped params)) '[column ::: ty]) where

295− table ! column = table ! 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

296245

297246instance

298− ( HasUnique table from columns

299− , Has column columns ty

300− , GroupedBy table column bys

301− ) => IsLabel column

302− (Expression schema from ('Grouped bys) params ty) where

303− 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)

304253instance

305− ( HasUnique table from columns

306− , Has column columns ty

307− , GroupedBy table column bys

308− ) => IsLabel column

309− ( Aliased (Expression schema from ('Grouped bys) params)

310− (column ::: ty) ) where

311− 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

312261instance

313− ( HasUnique table from columns

314− , Has column columns ty

315− , GroupedBy table column bys

316− ) => IsLabel column

317− ( NP (Aliased (Expression schema from ('Grouped bys) params))

318− '[column ::: ty] ) where

319− 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

320277

321278instance

322− ( Has table from columns

323− , Has column columns ty

324− , GroupedBy table column bys

325− ) => IsQualified table column

326− (Expression schema from ('Grouped bys) params ty) where

327− table ! column = UnsafeExpression $

328− renderAlias table <> "." <> 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

329286instance

330− ( Has table from columns

331− , Has column columns ty

332− , GroupedBy table column bys

333− ) => IsQualified table column

334− (Aliased (Expression schema from ('Grouped bys) params)

335− (column ::: ty)) where

336− table ! column = table ! 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

337294instance

338− ( Has table from columns

339− , Has column columns ty

340− , GroupedBy table column bys

341− ) => IsQualified table column

342− ( NP (Aliased (Expression schema from ('Grouped bys) params))

343− '[column ::: ty]) where

344− table ! column = table ! column :* Nil

345−

346−-- | analagous to `Nothing`

347−--

348−-- >>> printSQL null_

349−-- NULL

350−null_ :: Expression schema rels grouping params ('Null ty)

351−null_ = UnsafeExpression "NULL"

352−

353−-- | analagous to `Just`

354−--

355−-- >>> printSQL $ notNull true

356−-- TRUE

357−notNull

358− :: Expression schema rels grouping params ('NotNull ty)

359− -> Expression schema rels grouping params ('Null ty)

360−notNull = UnsafeExpression . renderExpression

361−

362−-- | return the leftmost value which is not NULL

363−--

364−-- >>> printSQL $ coalesce [null_, true] false

365−-- COALESCE(NULL, TRUE, FALSE)

366−coalesce

367− :: [Expression schema from grouping params ('Null ty)]

368− -- ^ @NULL@s may be present

369− -> Expression schema from grouping params ('NotNull ty)

370− -- ^ @NULL@ is absent

371− -> Expression schema from grouping params ('NotNull ty)

372−coalesce nullxs notNullx = UnsafeExpression $

373− "COALESCE" <> parenthesized (commaSeparated

374− ((renderExpression <$> nullxs) <> [renderExpression notNullx]))

375−

376−-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@

377−--

378−-- >>> printSQL $ fromNull true null_

379−-- COALESCE(NULL, TRUE)

380−fromNull

381− :: Expression schema from grouping params ('NotNull ty)

382− -- ^ what to convert @NULL@ to

383− -> Expression schema from grouping params ('Null ty)

384− -> Expression schema from grouping params ('NotNull ty)

385−fromNull notNullx nullx = coalesce [nullx] notNullx

386−

387−-- | >>> printSQL $ null_ & isNull

388−-- NULL IS NULL

389−isNull

390− :: Expression schema from grouping params ('Null ty)

391− -- ^ possibly @NULL@

392− -> Condition schema from grouping params

393−isNull x = UnsafeExpression $ renderExpression x <+> "IS NULL"

394−

395−-- | >>> printSQL $ null_ & isNotNull

396−-- NULL IS NOT NULL

397−isNotNull

398− :: Expression schema from grouping params ('Null ty)

399− -- ^ possibly @NULL@

400− -> Condition schema from grouping params

401−isNotNull x = UnsafeExpression $ renderExpression x <+> "IS NOT NULL"

402−

403−-- | analagous to `maybe` using @IS NULL@

404−--

405−-- >>> printSQL $ matchNull true not_ null_

406−-- CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END

407−matchNull

408− :: Expression schema from grouping params (nullty)

409− -- ^ what to convert @NULL@ to

410− -> ( Expression schema from grouping params ('NotNull ty)

411− -> Expression schema from grouping params (nullty) )

412− -- ^ function to perform when @NULL@ is absent

413− -> Expression schema from grouping params ('Null ty)

414− -> Expression schema from grouping params (nullty)

415−matchNull y f x = ifThenElse (isNull x) y

416− (f (UnsafeExpression (renderExpression x)))

417−

418−{-| right inverse to `fromNull`, if its arguments are equal then

419−`nullIf` gives @NULL@.

420−

421−>>> :set -XTypeApplications -XDataKinds

422−>>> let expr = nullIf false (param @1) :: Expression schema rels grp '[ 'NotNull 'PGbool] ('Null 'PGbool)

423−>>> printSQL expr

424−NULL IF (FALSE, ($1 :: bool))

425−-}

426−nullIf

427− :: Expression schema from grouping params ('NotNull ty)

428− -- ^ @NULL@ is absent

429− -> Expression schema from grouping params ('NotNull ty)

430− -- ^ @NULL@ is absent

431− -> Expression schema from grouping params ('Null ty)

432−nullIf x y = UnsafeExpression $ "NULL IF" <+> parenthesized

433− (renderExpression x <> ", " <> renderExpression y)

434−

435−-- | >>> printSQL $ array [null_, false, true]

436−-- ARRAY[NULL, FALSE, TRUE]

437−array

438− :: [Expression schema from grouping params ty]

439− -- ^ array elements

440− -> Expression schema from grouping params (nullity ('PGvararray ty))

441−array xs = UnsafeExpression $

442− "ARRAY[" <> commaSeparated (renderExpression <$> xs) <> "]"

443−

444−-- | >>> printSQL $ array [null_, false, true] & index 2

445−-- (ARRAY[NULL, FALSE, TRUE])[2]

446−index

447− :: Word64 -- ^ index

448− -> Expression schema from grouping params (nullity ('PGvararray ty)) -- ^ array

449− -> Expression schema from grouping params (NullifyType ty)

450−index n expr = UnsafeExpression $

451− parenthesized (renderExpression expr) <> "[" <> fromString (show n) <> "]"

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

452310

453311instance (KnownSymbol label, label `In` labels) => IsPGlabel label

454− (Expression schema from grouping params (nullity ('PGenum labels))) where

455− label = UnsafeExpression $ renderLabel (PGlabel @label)

456−

457−-- | A row constructor is an expression that builds a row value

458−-- (also called a composite value) using values for its member fields.

459−--

460−-- >>> :{

461−-- type Complex = 'PGcomposite

462−-- '[ "real" ::: 'NotNull 'PGfloat8

463−-- , "imaginary" ::: 'NotNull 'PGfloat8 ]

464−-- :}

465−--

466−-- >>> let i = row (0 `as` #real :* 1 `as` #imaginary) :: Expression '[] '[] 'Ungrouped '[] ('NotNull Complex)

467−-- >>> printSQL i

468−-- ROW(0, 1)

469−row

470− :: SListI row

471− => NP (Aliased (Expression schema from grouping params)) row

472− -- ^ zero or more expressions for the row field values

473− -> Expression schema from grouping params (nullity ('PGcomposite row))

474−row exprs = UnsafeExpression $ "ROW" <> parenthesized

475− (renderCommaSeparated (\ (expr `As` _) -> renderExpression expr) exprs)

476−

477−-- | >>> :{

478−-- type Complex = 'PGcomposite

479−-- '[ "real" ::: 'NotNull 'PGfloat8

480−-- , "imaginary" ::: 'NotNull 'PGfloat8 ]

481−-- :}

482−--

483−-- >>> let i = row (0 `as` #real :* 1 `as` #imaginary) :: Expression '["complex" ::: 'Typedef Complex] '[] 'Ungrouped '[] ('NotNull Complex)

484−-- >>> printSQL $ i & field #complex #imaginary

485−-- (ROW(0, 1)::"complex")."imaginary"

486−field

487− :: (Has tydef schema ('Typedef ('PGcomposite row)), Has field row ty)

488− => Alias tydef -- ^ row type

489− -> Alias field -- ^ field name

490− -> Expression schema from grouping params ('NotNull ('PGcomposite row))

491− -> Expression schema from grouping params ty

492−field td fld expr = UnsafeExpression $

493− parenthesized (renderExpression expr <> "::" <> renderAlias td)

494− <> "." <> renderAlias fld

495−

496−instance Semigroup

497− (Expression schema from grouping params (nullity ('PGvararray ty))) where

498− (<>) = unsafeBinaryOp "||"

499−

500−instance Monoid

501− (Expression schema from grouping params (nullity ('PGvararray ty))) where

502− mempty = array []

503− mappend = (<>)

504−

505−-- | >>> let expr = greatest currentTimestamp [param @1] :: Expression sch rels grp '[ 'NotNull 'PGtimestamptz] ('NotNull 'PGtimestamptz)

506−-- >>> printSQL expr

507−-- GREATEST(CURRENT_TIMESTAMP, ($1 :: timestamp with time zone))

508−greatest

509− :: Expression schema from grouping params (nullty)

510− -- ^ needs at least 1 argument

511− -> [Expression schema from grouping params (nullty)]

512− -- ^ or more

513− -> Expression schema from grouping params (nullty)

514−greatest x xs = UnsafeExpression $ "GREATEST("

515− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

516−

517−-- | >>> printSQL $ least currentTimestamp [null_]

518−-- LEAST(CURRENT_TIMESTAMP, NULL)

519−least

520− :: Expression schema from grouping params (nullty)

521− -- ^ needs at least 1 argument

522− -> [Expression schema from grouping params (nullty)]

523− -- ^ or more

524− -> Expression schema from grouping params (nullty)

525−least x xs = UnsafeExpression $ "LEAST("

526− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

312+ (Expression outer commons grp schemas params from (null ('PGenum labels))) where

313+ label = UnsafeExpression $ renderSQL (PGlabel @label)

527314

528315-- | >>> printSQL $ unsafeBinaryOp "OR" true false

529316-- (TRUE OR FALSE)

530−unsafeBinaryOp

531− :: ByteString

532− -- ^ operator

533− -> Expression schema from grouping params (ty0)

534− -> Expression schema from grouping params (ty1)

535− -> Expression schema from grouping params (ty2)

317+unsafeBinaryOp :: ByteString -> Operator ty0 ty1 ty2

536318unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

537− 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

538327

539−-- | >>> printSQL $ unsafeUnaryOp "NOT" true

328+-- | >>> printSQL $ unsafeLeftOp "NOT" true

540329-- (NOT TRUE)

541−unsafeUnaryOp

542− :: ByteString

543− -- ^ operator

544− -> Expression schema from grouping params (ty0)

545− -> Expression schema from grouping params (ty1)

546−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $

547− 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

548351

549352-- | >>> printSQL $ unsafeFunction "f" true

550353-- f(TRUE)

551−unsafeFunction

552− :: ByteString

553− -- ^ function

554− -> Expression schema from grouping params (xty)

555− -> Expression schema from grouping params (yty)

354+unsafeFunction :: ByteString -> x --> y

556355unsafeFunction fun x = UnsafeExpression $

557− fun <> parenthesized (renderExpression x)

558−

559−-- | Helper for defining variadic functions.

560−unsafeVariadicFunction

561− :: SListI elems

562− => ByteString

563− -- ^ function

564− -> NP (Expression schema from grouping params) elems

565− -> Expression schema from grouping params ret

566−unsafeVariadicFunction fun x = UnsafeExpression $

567− fun <> parenthesized (commaSeparated (hcollapse (hmap (K . renderExpression) x)))

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

568377

569378instance ty `In` PGNum

570− => Num (Expression schema from grouping params (nullity ty)) where

379+ => Num (Expression outer commons grp schemas params from (null ty)) where

571380 (+) = unsafeBinaryOp "+"

572381 (-) = unsafeBinaryOp "-"

573382 (*) = unsafeBinaryOp "*"

@@ -579,18 +388,23 @@ instance ty `In` PGNum

579388 . show

580389

581390instance (ty `In` PGNum, ty `In` PGFloating) => Fractional

582− (Expression schema from grouping params (nullity ty)) where

391+ (Expression outer commons grp schemas params from (null ty)) where

583392 (/) = unsafeBinaryOp "/"

584− fromRational x = fromInteger (numerator x) / fromInteger (denominator x)

393+ fromRational

394+ = UnsafeExpression

395+ . fromString

396+ . ($ "")

397+ . showFFloat Nothing

398+ . fromRat @Double

585399

586400instance (ty `In` PGNum, ty `In` PGFloating) => Floating

587− (Expression schema from grouping params (nullity ty)) where

401+ (Expression outer commons grp schemas params from (null ty)) where

588402 pi = UnsafeExpression "pi()"

589403 exp = unsafeFunction "exp"

590404 log = unsafeFunction "ln"

591405 sqrt = unsafeFunction "sqrt"

592406 b ** x = UnsafeExpression $

593− "power(" <> renderExpression b <> ", " <> renderExpression x <> ")"

407+ "power(" <> renderSQL b <> ", " <> renderSQL x <> ")"

594408 logBase b y = log y / log b

595409 sin = unsafeFunction "sin"

596410 cos = unsafeFunction "cos"

@@ -605,1154 +419,54 @@ instance (ty `In` PGNum, ty `In` PGFloating) => Floating

605419 acosh x = log (x + sqrt (x*x - 1))

606420 atanh x = log ((1 + x) / (1 - x)) / 2

607421

608−-- | >>> :{

609−-- let

610−-- expression :: Expression schema from grouping params (nullity 'PGfloat4)

611−-- expression = atan2_ pi 2

612−-- in printSQL expression

613−-- :}

614−-- atan2(pi(), 2)

615−atan2_

616− :: float `In` PGFloating

617− => Expression schema from grouping params (nullity float)

618− -- ^ numerator

619− -> Expression schema from grouping params (nullity float)

620− -- ^ denominator

621− -> Expression schema from grouping params (nullity float)

622−atan2_ y x = UnsafeExpression $

623− "atan2(" <> renderExpression y <> ", " <> renderExpression x <> ")"

624−

625−-- When a `cast` is applied to an `Expression` of a known type, it

626−-- represents a run-time type conversion. The cast will succeed only if a

627−-- suitable type conversion operation has been defined.

628−--

629−-- | >>> printSQL $ true & cast int4

630−-- (TRUE :: int4)

631−cast

632− :: TypeExpression schema ty1

633− -- ^ type to cast as

634− -> Expression schema from grouping params ty0

635− -- ^ value to convert

636− -> Expression schema from grouping params ty1

637−cast ty x = UnsafeExpression $ parenthesized $

638− renderExpression x <+> "::" <+> renderTypeExpression ty

639−

640−-- | integer division, truncates the result

641−--

642−-- >>> :{

643−-- let

644−-- expression :: Expression schema from grouping params (nullity 'PGint2)

645−-- expression = 5 `quot_` 2

646−-- in printSQL expression

647−-- :}

648−-- (5 / 2)

649−quot_

650− :: int `In` PGIntegral

651− => Expression schema from grouping params (nullity int)

652− -- ^ numerator

653− -> Expression schema from grouping params (nullity int)

654− -- ^ denominator

655− -> Expression schema from grouping params (nullity int)

656−quot_ = unsafeBinaryOp "/"

657−

658−-- | remainder upon integer division

659−--

660−-- >>> :{

661−-- let

662−-- expression :: Expression schema from grouping params (nullity 'PGint2)

663−-- expression = 5 `rem_` 2

664−-- in printSQL expression

665−-- :}

666−-- (5 % 2)

667−rem_

668− :: int `In` PGIntegral

669− => Expression schema from grouping params (nullity int)

670− -- ^ numerator

671− -> Expression schema from grouping params (nullity int)

672− -- ^ denominator

673− -> Expression schema from grouping params (nullity int)

674−rem_ = unsafeBinaryOp "%"

675−

676−-- | >>> :{

677−-- let

678−-- expression :: Expression schema from grouping params (nullity 'PGfloat4)

679−-- expression = trunc pi

680−-- in printSQL expression

681−-- :}

682−-- trunc(pi())

683−trunc

684− :: frac `In` PGFloating

685− => Expression schema from grouping params (nullity frac)

686− -- ^ fractional number

687− -> Expression schema from grouping params (nullity frac)

688−trunc = unsafeFunction "trunc"

689−

690−-- | >>> :{

691−-- let

692−-- expression :: Expression schema from grouping params (nullity 'PGfloat4)

693−-- expression = round_ pi

694−-- in printSQL expression

695−-- :}

696−-- round(pi())

697−round_

698− :: frac `In` PGFloating

699− => Expression schema from grouping params (nullity frac)

700− -- ^ fractional number

701− -> Expression schema from grouping params (nullity frac)

702−round_ = unsafeFunction "round"

703−

704−-- | >>> :{

705−-- let

706−-- expression :: Expression schema from grouping params (nullity 'PGfloat4)

707−-- expression = ceiling_ pi

708−-- in printSQL expression

709−-- :}

710−-- ceiling(pi())

711−ceiling_

712− :: frac `In` PGFloating

713− => Expression schema from grouping params (nullity frac)

714− -- ^ fractional number

715− -> Expression schema from grouping params (nullity frac)

716−ceiling_ = unsafeFunction "ceiling"

717−

718−-- | A `Condition` is an `Expression`, which can evaluate

719−-- to `true`, `false` or `null_`. This is because SQL uses

720−-- a three valued logic.

721−type Condition schema from grouping params =

722− Expression schema from grouping params ('Null 'PGbool)

723−

724−-- | >>> printSQL true

725−-- TRUE

726−true :: Expression schema from grouping params (nullity 'PGbool)

727−true = UnsafeExpression "TRUE"

728−

729−-- | >>> printSQL false

730−-- FALSE

731−false :: Expression schema from grouping params (nullity 'PGbool)

732−false = UnsafeExpression "FALSE"

733−

734−-- | >>> printSQL $ not_ true

735−-- (NOT TRUE)

736−not_

737− :: Expression schema from grouping params (nullity 'PGbool)

738− -> Expression schema from grouping params (nullity 'PGbool)

739−not_ = unsafeUnaryOp "NOT"

740−

741−-- | >>> printSQL $ true .&& false

742−-- (TRUE AND FALSE)

743−(.&&)

744− :: Expression schema from grouping params (nullity 'PGbool)

745− -> Expression schema from grouping params (nullity 'PGbool)

746− -> Expression schema from grouping params (nullity 'PGbool)

747−infixr 3 .&&

748−(.&&) = unsafeBinaryOp "AND"

749−

750−-- | >>> printSQL $ true .|| false

751−-- (TRUE OR FALSE)

752−(.||)

753− :: Expression schema from grouping params (nullity 'PGbool)

754− -> Expression schema from grouping params (nullity 'PGbool)

755− -> Expression schema from grouping params (nullity 'PGbool)

756−infixr 2 .||

757−(.||) = unsafeBinaryOp "OR"

758−

759−-- | >>> :{

760−-- let

761−-- expression :: Expression schema from grouping params (nullity 'PGint2)

762−-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3

763−-- in printSQL expression

764−-- :}

765−-- CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END

766−caseWhenThenElse

767− :: [ ( Condition schema from grouping params

768− , Expression schema from grouping params ty

769− ) ]

770− -- ^ whens and thens

771− -> Expression schema from grouping params ty

772− -- ^ else

773− -> Expression schema from grouping params ty

774−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat

775− [ "CASE"

776− , mconcat

777− [ mconcat

778− [ " WHEN ", renderExpression when_

779− , " THEN ", renderExpression then_

780− ]

781− | (when_,then_) <- whenThens

782− ]

783− , " ELSE ", renderExpression else_

784− , " END"

785− ]

786−

787−-- | >>> :{

788−-- let

789−-- expression :: Expression schema from grouping params (nullity 'PGint2)

790−-- expression = ifThenElse true 1 0

791−-- in printSQL expression

792−-- :}

793−-- CASE WHEN TRUE THEN 1 ELSE 0 END

794−ifThenElse

795− :: Condition schema from grouping params

796− -> Expression schema from grouping params ty -- ^ then

797− -> Expression schema from grouping params ty -- ^ else

798− -> Expression schema from grouping params ty

799−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_

800−

801−-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`

802−-- will produce @NULL@s if one of their arguments is @NULL@.

803−--

804−-- >>> printSQL $ true .== null_

805−-- (TRUE = NULL)

806−(.==)

807− :: Expression schema from grouping params (nullity0 ty) -- ^ lhs

808− -> Expression schema from grouping params (nullity1 ty) -- ^ rhs

809− -> Condition schema from grouping params

810−(.==) = unsafeBinaryOp "="

811−infix 4 .==

812−

813−-- | >>> printSQL $ true ./= null_

814−-- (TRUE <> NULL)

815−(./=)

816− :: Expression schema from grouping params (nullity0 ty) -- ^ lhs

817− -> Expression schema from grouping params (nullity1 ty) -- ^ rhs

818− -> Condition schema from grouping params

819−(./=) = unsafeBinaryOp "<>"

820−infix 4 ./=

821−

822−-- | >>> printSQL $ true .>= null_

823−-- (TRUE >= NULL)

824−(.>=)

825− :: Expression schema from grouping params (nullity0 ty) -- ^ lhs

826− -> Expression schema from grouping params (nullity1 ty) -- ^ rhs

827− -> Condition schema from grouping params

828−(.>=) = unsafeBinaryOp ">="

829−infix 4 .>=

830−

831−-- | >>> printSQL $ true .< null_

832−-- (TRUE < NULL)

833−(.<)

834− :: Expression schema from grouping params (nullity0 ty) -- ^ lhs

835− -> Expression schema from grouping params (nullity1 ty) -- ^ rhs

836− -> Condition schema from grouping params

837−(.<) = unsafeBinaryOp "<"

838−infix 4 .<

839−

840−-- | >>> printSQL $ true .<= null_

841−-- (TRUE <= NULL)

842−(.<=)

843− :: Expression schema from grouping params (nullity0 ty) -- ^ lhs

844− -> Expression schema from grouping params (nullity1 ty) -- ^ rhs

845− -> Condition schema from grouping params

846−(.<=) = unsafeBinaryOp "<="

847−infix 4 .<=

848−

849−-- | >>> printSQL $ true .> null_

850−-- (TRUE > NULL)

851−(.>)

852− :: Expression schema from grouping params (nullity0 ty) -- ^ lhs

853− -> Expression schema from grouping params (nullity1 ty) -- ^ rhs

854− -> Condition schema from grouping params

855−(.>) = unsafeBinaryOp ">"

856−infix 4 .>

857−

858−-- | >>> printSQL currentDate

859−-- CURRENT_DATE

860−currentDate

861− :: Expression schema from grouping params (nullity 'PGdate)

862−currentDate = UnsafeExpression "CURRENT_DATE"

863−

864−-- | >>> printSQL currentTime

865−-- CURRENT_TIME

866−currentTime

867− :: Expression schema from grouping params (nullity 'PGtimetz)

868−currentTime = UnsafeExpression "CURRENT_TIME"

869−

870−-- | >>> printSQL currentTimestamp

871−-- CURRENT_TIMESTAMP

872−currentTimestamp

873− :: Expression schema from grouping params (nullity 'PGtimestamptz)

874−currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"

875−

876−-- | >>> printSQL localTime

877−-- LOCALTIME

878−localTime

879− :: Expression schema from grouping params (nullity 'PGtime)

880−localTime = UnsafeExpression "LOCALTIME"

881−

882−-- | >>> printSQL localTimestamp

883−-- LOCALTIMESTAMP

884−localTimestamp

885− :: Expression schema from grouping params (nullity 'PGtimestamp)

886−localTimestamp = UnsafeExpression "LOCALTIMESTAMP"

887−

888−{-----------------------------------------

889−text

890−-----------------------------------------}

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)

891438

892439instance IsString

893− (Expression schema from grouping params (nullity 'PGtext)) where

440+ (Expression outer commons grp schemas params from (null 'PGtext)) where

894441 fromString str = UnsafeExpression $

895442 "E\'" <> fromString (escape =<< str) <> "\'"

896− where

897− escape = \case

898− '\NUL' -> "\\0"

899− '\'' -> "''"

900− '"' -> "\\\""

901− '\b' -> "\\b"

902− '\n' -> "\\n"

903− '\r' -> "\\r"

904− '\t' -> "\\t"

905− '\\' -> "\\\\"

906− 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) <> "\'"

907451

908452instance Semigroup

909− (Expression schema from 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

910463 (<>) = unsafeBinaryOp "||"

911464

912465instance Monoid

913− (Expression schema from 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

914471 mempty = fromString ""

915472 mappend = (<>)

916−

917−-- | >>> printSQL $ lower "ARRRGGG"

918−-- lower(E'ARRRGGG')

919−lower

920− :: Expression schema from grouping params (nullity 'PGtext)

921− -- ^ string to lower case

922− -> Expression schema from grouping params (nullity 'PGtext)

923−lower = unsafeFunction "lower"

924−

925−-- | >>> printSQL $ upper "eeee"

926−-- upper(E'eeee')

927−upper

928− :: Expression schema from grouping params (nullity 'PGtext)

929− -- ^ string to upper case

930− -> Expression schema from grouping params (nullity 'PGtext)

931−upper = unsafeFunction "upper"

932−

933−-- | >>> printSQL $ charLength "four"

934−-- char_length(E'four')

935−charLength

936− :: Expression schema from grouping params (nullity 'PGtext)

937− -- ^ string to measure

938− -> Expression schema from grouping params (nullity 'PGint4)

939−charLength = unsafeFunction "char_length"

940−

941−-- | The `like` expression returns true if the @string@ matches

942−-- the supplied @pattern@. If @pattern@ does not contain percent signs

943−-- or underscores, then the pattern only represents the string itself;

944−-- in that case `like` acts like the equals operator. An underscore (_)

945−-- in pattern stands for (matches) any single character; a percent sign (%)

946−-- matches any sequence of zero or more characters.

947−--

948−-- >>> printSQL $ "abc" `like` "a%"

949−-- (E'abc' LIKE E'a%')

950−like

951− :: Expression schema from grouping params (nullity 'PGtext)

952− -- ^ string

953− -> Expression schema from grouping params (nullity 'PGtext)

954− -- ^ pattern

955− -> Expression schema from grouping params (nullity 'PGbool)

956−like = unsafeBinaryOp "LIKE"

957−

958−{-----------------------------------------

959− -- json and jsonb support

960−

961−See https://www.postgresql.org/docs/10/static/functions-json.html -- most

962−comments lifted directly from this page.

963−

964−Table 9.44: json and jsonb operators

965−-----------------------------------------}

966−

967−-- | Get JSON value (object field or array element) at a key.

968−(.->)

969− :: (json `In` PGJsonType, key `In` PGJsonKey)

970− => Expression schema from grouping params (nullity json)

971− -> Expression schema from grouping params (nullity key)

972− -> Expression schema from grouping params ('Null json)

973−infixl 8 .->

974−(.->) = unsafeBinaryOp "->"

975−

976−-- | Get JSON value (object field or array element) at a key, as text.

977−(.->>)

978− :: (json `In` PGJsonType, key `In` PGJsonKey)

979− => Expression schema from grouping params (nullity json)

980− -> Expression schema from grouping params (nullity key)

981− -> Expression schema from grouping params ('Null 'PGtext)

982−infixl 8 .->>

983−(.->>) = unsafeBinaryOp "->>"

984−

985−-- | Get JSON value at a specified path.

986−(.#>)

987− :: (json `In` PGJsonType, PGTextArray "(.#>)" path)

988− => Expression schema from grouping params (nullity json)

989− -> Expression schema from grouping params (nullity path)

990− -> Expression schema from grouping params ('Null json)

991−infixl 8 .#>

992−(.#>) = unsafeBinaryOp "#>"

993−

994−-- | Get JSON value at a specified path as text.

995−(.#>>)

996− :: (json `In` PGJsonType, PGTextArray "(.#>>)" path)

997− => Expression schema from grouping params (nullity json)

998− -> Expression schema from grouping params (nullity path)

999− -> Expression schema from grouping params ('Null 'PGtext)

1000−infixl 8 .#>>

1001−(.#>>) = unsafeBinaryOp "#>>"

1002−

1003−-- Additional jsonb operators

1004−

1005−-- | Does the left JSON value contain the right JSON path/value entries at the

1006−-- top level?

1007−(.@>)

1008− :: Expression schema from grouping params (nullity 'PGjsonb)

1009− -> Expression schema from grouping params (nullity 'PGjsonb)

1010− -> Condition schema from grouping params

1011−infixl 9 .@>

1012−(.@>) = unsafeBinaryOp "@>"

1013−

1014−-- | Are the left JSON path/value entries contained at the top level within the

1015−-- right JSON value?

1016−(.<@)

1017− :: Expression schema from grouping params (nullity 'PGjsonb)

1018− -> Expression schema from grouping params (nullity 'PGjsonb)

1019− -> Condition schema from grouping params

1020−infixl 9 .<@

1021−(.<@) = unsafeBinaryOp "<@"

1022−

1023−-- | Does the string exist as a top-level key within the JSON value?

1024−(.?)

1025− :: Expression schema from grouping params (nullity 'PGjsonb)

1026− -> Expression schema from grouping params (nullity 'PGtext)

1027− -> Condition schema from grouping params

1028−infixl 9 .?

1029−(.?) = unsafeBinaryOp "?"

1030−

1031−-- | Do any of these array strings exist as top-level keys?

1032−(.?|)

1033− :: Expression schema from grouping params (nullity 'PGjsonb)

1034− -> Expression schema from grouping params (nullity ('PGvararray ('NotNull 'PGtext)))

1035− -> Condition schema from grouping params

1036−infixl 9 .?|

1037−(.?|) = unsafeBinaryOp "?|"

1038−

1039−-- | Do all of these array strings exist as top-level keys?

1040−(.?&)

1041− :: Expression schema from grouping params (nullity 'PGjsonb)

1042− -> Expression schema from grouping params (nullity ('PGvararray ('NotNull 'PGtext)))

1043− -> Condition schema from grouping params

1044−infixl 9 .?&

1045−(.?&) = unsafeBinaryOp "?&"

1046−

1047−-- | Concatenate two jsonb values into a new jsonb value.

1048−instance

1049− Semigroup (Expression schema from grouping param (nullity 'PGjsonb)) where

1050− (<>) = unsafeBinaryOp "||"

1051−

1052−-- | Delete a key or keys from a JSON object, or remove an array element.

1053−--

1054−-- If the right operand is..

1055−--

1056−-- @ text @: Delete key/value pair or string element from left operand. Key/value pairs

1057−-- are matched based on their key value.

1058−--

1059−-- @ text[] @: Delete multiple key/value pairs or string elements

1060−-- from left operand. Key/value pairs are matched based on their key value.

1061−--

1062−-- @ integer @: Delete the array element with specified index (Negative integers

1063−-- count from the end). Throws an error if top level container is not an array.

1064−(.-.)

1065− :: (key `In` '[ 'PGtext, 'PGvararray ('NotNull 'PGtext), 'PGint4, 'PGint2 ]) -- hlint error without parens here

1066− => Expression schema from grouping params (nullity 'PGjsonb)

1067− -> Expression schema from grouping params (nullity key)

1068− -> Expression schema from grouping params (nullity 'PGjsonb)

1069−infixl 6 .-.

1070−(.-.) = unsafeBinaryOp "-"

1071−

1072−-- | Delete the field or element with specified path (for JSON arrays, negative

1073−-- integers count from the end)

1074−(#-.)

1075− :: PGTextArray "(#-.)" arrayty

1076− => Expression schema from grouping params (nullity 'PGjsonb)

1077− -> Expression schema from grouping params (nullity arrayty)

1078− -> Expression schema from grouping params (nullity 'PGjsonb)

1079−infixl 6 #-.

1080−(#-.) = unsafeBinaryOp "#-"

1081−

1082−{-----------------------------------------

1083−Table 9.45: JSON creation functions

1084−-----------------------------------------}

1085−

1086−-- | Literal binary JSON

1087−jsonbLit

1088− :: JSON.ToJSON x

1089− => x -> Expression schema from grouping params (nullity 'PGjsonb)

1090−jsonbLit = cast jsonb . UnsafeExpression

1091− . singleQuotedUtf8 . toStrict . JSON.encode

1092−

1093−-- | Literal JSON

1094−jsonLit

1095− :: JSON.ToJSON x

1096− => x -> Expression schema from grouping params (nullity 'PGjson)

1097−jsonLit = cast json . UnsafeExpression

1098− . singleQuotedUtf8 . toStrict . JSON.encode

1099−

1100−-- | Returns the value as json. Arrays and composites are converted

1101−-- (recursively) to arrays and objects; otherwise, if there is a cast from the

1102−-- type to json, the cast function will be used to perform the conversion;

1103−-- otherwise, a scalar value is produced. For any scalar type other than a

1104−-- number, a Boolean, or a null value, the text representation will be used, in

1105−-- such a fashion that it is a valid json value.

1106−toJson

1107− :: Expression schema from grouping params (nullity ty)

1108− -> Expression schema from grouping params (nullity 'PGjson)

1109−toJson = unsafeFunction "to_json"

1110−

1111−-- | Returns the value as jsonb. Arrays and composites are converted

1112−-- (recursively) to arrays and objects; otherwise, if there is a cast from the

1113−-- type to json, the cast function will be used to perform the conversion;

1114−-- otherwise, a scalar value is produced. For any scalar type other than a

1115−-- number, a Boolean, or a null value, the text representation will be used, in

1116−-- such a fashion that it is a valid jsonb value.

1117−toJsonb

1118− :: Expression schema from grouping params (nullity ty)

1119− -> Expression schema from grouping params (nullity 'PGjsonb)

1120−toJsonb = unsafeFunction "to_jsonb"

1121−

1122−-- | Returns the array as a JSON array. A PostgreSQL multidimensional array

1123−-- becomes a JSON array of arrays.

1124−arrayToJson

1125− :: PGArray "arrayToJson" arr

1126− => Expression schema from grouping params (nullity arr)

1127− -> Expression schema from grouping params (nullity 'PGjson)

1128−arrayToJson = unsafeFunction "array_to_json"

1129−

1130−-- | Returns the row as a JSON object.

1131−rowToJson

1132− :: Expression schema from grouping params (nullity ('PGcomposite ty))

1133− -> Expression schema from grouping params (nullity 'PGjson)

1134−rowToJson = unsafeFunction "row_to_json"

1135−

1136−-- | Builds a possibly-heterogeneously-typed JSON array out of a variadic

1137−-- argument list.

1138−jsonBuildArray

1139− :: SListI elems

1140− => NP (Expression schema from grouping params) elems

1141− -> Expression schema from grouping params (nullity 'PGjson)

1142−jsonBuildArray = unsafeVariadicFunction "json_build_array"

1143−

1144−-- | Builds a possibly-heterogeneously-typed (binary) JSON array out of a

1145−-- variadic argument list.

1146−jsonbBuildArray

1147− :: SListI elems

1148− => NP (Expression schema from grouping params) elems

1149− -> Expression schema from grouping params (nullity 'PGjsonb)

1150−jsonbBuildArray = unsafeVariadicFunction "jsonb_build_array"

1151−

1152−unsafeRowFunction

1153− :: All Top elems

1154− => NP (Aliased (Expression schema from grouping params)) elems

1155− -> [ByteString]

1156−unsafeRowFunction =

1157− (`appEndo` []) . hcfoldMap (Proxy :: Proxy Top)

1158− (\(col `As` name) -> Endo $ \xs ->

1159− renderAliasString name : renderExpression col : xs)

1160−

1161−-- | Builds a possibly-heterogeneously-typed JSON object out of a variadic

1162−-- argument list. The elements of the argument list must alternate between text

1163−-- and values.

1164−jsonBuildObject

1165− :: All Top elems

1166− => NP (Aliased (Expression schema from grouping params)) elems

1167− -> Expression schema from grouping params (nullity 'PGjson)

1168−jsonBuildObject

1169− = unsafeFunction "json_build_object"

1170− . UnsafeExpression

1171− . commaSeparated

1172− . unsafeRowFunction

1173−

1174−-- | Builds a possibly-heterogeneously-typed (binary) JSON object out of a

1175−-- variadic argument list. The elements of the argument list must alternate

1176−-- between text and values.

1177−jsonbBuildObject

1178− :: All Top elems

1179− => NP (Aliased (Expression schema from grouping params)) elems

1180− -> Expression schema from grouping params (nullity 'PGjsonb)

1181−jsonbBuildObject

1182− = unsafeFunction "jsonb_build_object"

1183− . UnsafeExpression

1184− . commaSeparated

1185− . unsafeRowFunction

1186−

1187−-- | Builds a JSON object out of a text array. The array must have either

1188−-- exactly one dimension with an even number of members, in which case they are

1189−-- taken as alternating key/value pairs, or two dimensions such that each inner

1190−-- array has exactly two elements, which are taken as a key/value pair.

1191−jsonObject

1192− :: PGArrayOf "jsonObject" arr ('NotNull 'PGtext)

1193− => Expression schema from grouping params (nullity arr)

1194− -> Expression schema from grouping params (nullity 'PGjson)

1195−jsonObject = unsafeFunction "json_object"

1196−

1197−-- | Builds a binary JSON object out of a text array. The array must have either

1198−-- exactly one dimension with an even number of members, in which case they are

1199−-- taken as alternating key/value pairs, or two dimensions such that each inner

1200−-- array has exactly two elements, which are taken as a key/value pair.

1201−jsonbObject

1202− :: PGArrayOf "jsonbObject" arr ('NotNull 'PGtext)

1203− => Expression schema from grouping params (nullity arr)

1204− -> Expression schema from grouping params (nullity 'PGjsonb)

1205−jsonbObject = unsafeFunction "jsonb_object"

1206−

1207−-- | This is an alternate form of 'jsonObject' that takes two arrays; one for

1208−-- keys and one for values, that are zipped pairwise to create a JSON object.

1209−jsonZipObject

1210− :: ( PGArrayOf "jsonZipObject" keysArray ('NotNull 'PGtext)

1211− , PGArrayOf "jsonZipObject" valuesArray ('NotNull 'PGtext))

1212− => Expression schema from grouping params (nullity keysArray)

1213− -> Expression schema from grouping params (nullity valuesArray)

1214− -> Expression schema from grouping params (nullity 'PGjson)

1215−jsonZipObject ks vs =

1216− unsafeVariadicFunction "json_object" (ks :* vs :* Nil)

1217−

1218−-- | This is an alternate form of 'jsonObject' that takes two arrays; one for

1219−-- keys and one for values, that are zipped pairwise to create a binary JSON

1220−-- object.

1221−jsonbZipObject

1222− :: ( PGArrayOf "jsonbZipObject" keysArray ('NotNull 'PGtext)

1223− , PGArrayOf "jsonbZipObject" valuesArray ('NotNull 'PGtext))

1224− => Expression schema from grouping params (nullity keysArray)

1225− -> Expression schema from grouping params (nullity valuesArray)

1226− -> Expression schema from grouping params (nullity 'PGjsonb)

1227−jsonbZipObject ks vs =

1228− unsafeVariadicFunction "jsonb_object" (ks :* vs :* Nil)

1229−

1230−{-----------------------------------------

1231−Table 9.46: JSON processing functions

1232−-----------------------------------------}

1233−

1234−-- | Returns the number of elements in the outermost JSON array.

1235−jsonArrayLength

1236− :: Expression schema from grouping params (nullity 'PGjson)

1237− -> Expression schema from grouping params (nullity 'PGint4)

1238−jsonArrayLength = unsafeFunction "json_array_length"

1239−

1240−-- | Returns the number of elements in the outermost binary JSON array.

1241−jsonbArrayLength

1242− :: Expression schema from grouping params (nullity 'PGjsonb)

1243− -> Expression schema from grouping params (nullity 'PGint4)

1244−jsonbArrayLength = unsafeFunction "jsonb_array_length"

1245−

1246−-- | Returns JSON value pointed to by the given path (equivalent to #>

1247−-- operator).

1248−jsonExtractPath

1249− :: SListI elems

1250− => Expression schema from grouping params (nullity 'PGjson)

1251− -> NP (Expression schema from grouping params) elems

1252− -> Expression schema from grouping params (nullity 'PGjsonb)

1253−jsonExtractPath x xs =

1254− unsafeVariadicFunction "json_extract_path" (x :* xs)

1255−

1256−-- | Returns JSON value pointed to by the given path (equivalent to #>

1257−-- operator).

1258−jsonbExtractPath

1259− :: SListI elems

1260− => Expression schema from grouping params (nullity 'PGjsonb)

1261− -> NP (Expression schema from grouping params) elems

1262− -> Expression schema from grouping params (nullity 'PGjsonb)

1263−jsonbExtractPath x xs =

1264− unsafeVariadicFunction "jsonb_extract_path" (x :* xs)

1265−

1266−-- | Returns JSON value pointed to by the given path (equivalent to #>

1267−-- operator), as text.

1268−jsonExtractPathAsText

1269− :: SListI elems

1270− => Expression schema from grouping params (nullity 'PGjson)

1271− -> NP (Expression schema from grouping params) elems

1272− -> Expression schema from grouping params (nullity 'PGjson)

1273−jsonExtractPathAsText x xs =

1274− unsafeVariadicFunction "json_extract_path_text" (x :* xs)

1275−

1276−-- | Returns JSON value pointed to by the given path (equivalent to #>

1277−-- operator), as text.

1278−jsonbExtractPathAsText

1279− :: SListI elems

1280− => Expression schema from grouping params (nullity 'PGjsonb)

1281− -> NP (Expression schema from grouping params) elems

1282− -> Expression schema from grouping params (nullity 'PGjsonb)

1283−jsonbExtractPathAsText x xs =

1284− unsafeVariadicFunction "jsonb_extract_path_text" (x :* xs)

1285−

1286−-- | Returns the type of the outermost JSON value as a text string. Possible

1287−-- types are object, array, string, number, boolean, and null.

1288−jsonTypeof

1289− :: Expression schema from grouping params (nullity 'PGjson)

1290− -> Expression schema from grouping params (nullity 'PGtext)

1291−jsonTypeof = unsafeFunction "json_typeof"

1292−

1293−-- | Returns the type of the outermost binary JSON value as a text string.

1294−-- Possible types are object, array, string, number, boolean, and null.

1295−jsonbTypeof

1296− :: Expression schema from grouping params (nullity 'PGjsonb)

1297− -> Expression schema from grouping params (nullity 'PGtext)

1298−jsonbTypeof = unsafeFunction "jsonb_typeof"

1299−

1300−-- | Returns its argument with all object fields that have null values omitted.

1301−-- Other null values are untouched.

1302−jsonStripNulls

1303− :: Expression schema from grouping params (nullity 'PGjson)

1304− -> Expression schema from grouping params (nullity 'PGjson)

1305−jsonStripNulls = unsafeFunction "json_strip_nulls"

1306−

1307−-- | Returns its argument with all object fields that have null values omitted.

1308−-- Other null values are untouched.

1309−jsonbStripNulls

1310− :: Expression schema from grouping params (nullity 'PGjsonb)

1311− -> Expression schema from grouping params (nullity 'PGjsonb)

1312−jsonbStripNulls = unsafeFunction "jsonb_strip_nulls"

1313−

1314−-- | @ jsonbSet target path new_value create_missing @

1315−--

1316−-- Returns target with the section designated by path replaced by new_value,

1317−-- or with new_value added if create_missing is true ( default is true) and the

1318−-- item designated by path does not exist. As with the path orientated

1319−-- operators, negative integers that appear in path count from the end of JSON

1320−-- arrays.

1321−jsonbSet

1322− :: PGTextArray "jsonbSet" arr

1323− => Expression schema from grouping params (nullity 'PGjsonb)

1324− -> Expression schema from grouping params (nullity arr)

1325− -> Expression schema from grouping params (nullity 'PGjsonb)

1326− -> Maybe (Expression schema from grouping params (nullity 'PGbool))

1327− -> Expression schema from grouping params (nullity 'PGjsonb)

1328−jsonbSet tgt path val createMissing = case createMissing of

1329− Just m -> unsafeVariadicFunction "jsonb_set" (tgt :* path :* val :* m :* Nil)

1330− Nothing -> unsafeVariadicFunction "jsonb_set" (tgt :* path :* val :* Nil)

1331−

1332−-- | @ jsonbInsert target path new_value insert_after @

1333−--

1334−-- Returns target with new_value inserted. If target section designated by

1335−-- path is in a JSONB array, new_value will be inserted before target or after

1336−-- if insert_after is true (default is false). If target section designated by

1337−-- path is in JSONB object, new_value will be inserted only if target does not

1338−-- exist. As with the path orientated operators, negative integers that appear

1339−-- in path count from the end of JSON arrays.

1340−jsonbInsert

1341− :: PGTextArray "jsonbInsert" arr

1342− => Expression schema from grouping params (nullity 'PGjsonb)

1343− -> Expression schema from grouping params (nullity arr)

1344− -> Expression schema from grouping params (nullity 'PGjsonb)

1345− -> Maybe (Expression schema from grouping params (nullity 'PGbool))

1346− -> Expression schema from grouping params (nullity 'PGjsonb)

1347−jsonbInsert tgt path val insertAfter = case insertAfter of

1348− Just i -> unsafeVariadicFunction "jsonb_insert" (tgt :* path :* val :* i :* Nil)

1349− Nothing -> unsafeVariadicFunction "jsonb_insert" (tgt :* path :* val :* Nil)

1350−

1351−-- | Returns its argument as indented JSON text.

1352−jsonbPretty

1353− :: Expression schema from grouping params (nullity 'PGjsonb)

1354− -> Expression schema from grouping params (nullity 'PGtext)

1355−jsonbPretty = unsafeFunction "jsonb_pretty"

1356−

1357−{-----------------------------------------

1358−aggregation

1359−-----------------------------------------}

1360−

1361−-- | escape hatch to define aggregate functions

1362−unsafeAggregate

1363− :: ByteString -- ^ aggregate function

1364− -> Expression schema from 'Ungrouped params (xty)

1365− -> Expression schema from ('Grouped bys) params (yty)

1366−unsafeAggregate fun x = UnsafeExpression $ mconcat

1367− [fun, "(", renderExpression x, ")"]

1368−

1369−-- | escape hatch to define aggregate functions over distinct values

1370−unsafeAggregateDistinct

1371− :: ByteString -- ^ aggregate function

1372− -> Expression schema from 'Ungrouped params (xty)

1373− -> Expression schema from ('Grouped bys) params (yty)

1374−unsafeAggregateDistinct fun x = UnsafeExpression $ mconcat

1375− [fun, "(DISTINCT ", renderExpression x, ")"]

1376−

1377−-- | >>> :{

1378−-- let

1379−-- expression :: Expression schema '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Grouped bys) params ('Null 'PGnumeric)

1380−-- expression = sum_ #col

1381−-- in printSQL expression

1382−-- :}

1383−-- sum("col")

1384−sum_

1385− :: ty `In` PGNum

1386− => Expression schema from 'Ungrouped params (nullity ty)

1387− -- ^ what to sum

1388− -> Expression schema from ('Grouped bys) params (nullity ty)

1389−sum_ = unsafeAggregate "sum"

1390−

1391−-- | >>> :{

1392−-- let

1393−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGnumeric]] ('Grouped bys) params (nullity 'PGnumeric)

1394−-- expression = sumDistinct #col

1395−-- in printSQL expression

1396−-- :}

1397−-- sum(DISTINCT "col")

1398−sumDistinct

1399− :: ty `In` PGNum

1400− => Expression schema from 'Ungrouped params (nullity ty)

1401− -- ^ what to sum

1402− -> Expression schema from ('Grouped bys) params (nullity ty)

1403−sumDistinct = unsafeAggregateDistinct "sum"

1404−

1405−-- | A constraint for `PGType`s that you can take averages of and the resulting

1406−-- `PGType`.

1407−class PGAvg ty avg | ty -> avg where

1408− avg, avgDistinct

1409− :: Expression schema from 'Ungrouped params (nullity ty)

1410− -- ^ what to average

1411− -> Expression schema from ('Grouped bys) params (nullity avg)

1412− avg = unsafeAggregate "avg"

1413− avgDistinct = unsafeAggregateDistinct "avg"

1414−instance PGAvg 'PGint2 'PGnumeric

1415−instance PGAvg 'PGint4 'PGnumeric

1416−instance PGAvg 'PGint8 'PGnumeric

1417−instance PGAvg 'PGnumeric 'PGnumeric

1418−instance PGAvg 'PGfloat4 'PGfloat8

1419−instance PGAvg 'PGfloat8 'PGfloat8

1420−instance PGAvg 'PGinterval 'PGinterval

1421−

1422−-- | >>> :{

1423−-- let

1424−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1425−-- expression = bitAnd #col

1426−-- in printSQL expression

1427−-- :}

1428−-- bit_and("col")

1429−bitAnd

1430− :: int `In` PGIntegral

1431− => Expression schema from 'Ungrouped params (nullity int)

1432− -- ^ what to aggregate

1433− -> Expression schema from ('Grouped bys) params (nullity int)

1434−bitAnd = unsafeAggregate "bit_and"

1435−

1436−-- | >>> :{

1437−-- let

1438−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1439−-- expression = bitOr #col

1440−-- in printSQL expression

1441−-- :}

1442−-- bit_or("col")

1443−bitOr

1444− :: int `In` PGIntegral

1445− => Expression schema from 'Ungrouped params (nullity int)

1446− -- ^ what to aggregate

1447− -> Expression schema from ('Grouped bys) params (nullity int)

1448−bitOr = unsafeAggregate "bit_or"

1449−

1450−-- | >>> :{

1451−-- let

1452−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1453−-- expression = bitAndDistinct #col

1454−-- in printSQL expression

1455−-- :}

1456−-- bit_and(DISTINCT "col")

1457−bitAndDistinct

1458− :: int `In` PGIntegral

1459− => Expression schema from 'Ungrouped params (nullity int)

1460− -- ^ what to aggregate

1461− -> Expression schema from ('Grouped bys) params (nullity int)

1462−bitAndDistinct = unsafeAggregateDistinct "bit_and"

1463−

1464−-- | >>> :{

1465−-- let

1466−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1467−-- expression = bitOrDistinct #col

1468−-- in printSQL expression

1469−-- :}

1470−-- bit_or(DISTINCT "col")

1471−bitOrDistinct

1472− :: int `In` PGIntegral

1473− => Expression schema from 'Ungrouped params (nullity int)

1474− -- ^ what to aggregate

1475− -> Expression schema from ('Grouped bys) params (nullity int)

1476−bitOrDistinct = unsafeAggregateDistinct "bit_or"

1477−

1478−-- | >>> :{

1479−-- let

1480−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1481−-- expression = boolAnd #col

1482−-- in printSQL expression

1483−-- :}

1484−-- bool_and("col")

1485−boolAnd

1486− :: Expression schema from 'Ungrouped params (nullity 'PGbool)

1487− -- ^ what to aggregate

1488− -> Expression schema from ('Grouped bys) params (nullity 'PGbool)

1489−boolAnd = unsafeAggregate "bool_and"

1490−

1491−-- | >>> :{

1492−-- let

1493−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1494−-- expression = boolOr #col

1495−-- in printSQL expression

1496−-- :}

1497−-- bool_or("col")

1498−boolOr

1499− :: Expression schema from 'Ungrouped params (nullity 'PGbool)

1500− -- ^ what to aggregate

1501− -> Expression schema from ('Grouped bys) params (nullity 'PGbool)

1502−boolOr = unsafeAggregate "bool_or"

1503−

1504−-- | >>> :{

1505−-- let

1506−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1507−-- expression = boolAndDistinct #col

1508−-- in printSQL expression

1509−-- :}

1510−-- bool_and(DISTINCT "col")

1511−boolAndDistinct

1512− :: Expression schema from 'Ungrouped params (nullity 'PGbool)

1513− -- ^ what to aggregate

1514− -> Expression schema from ('Grouped bys) params (nullity 'PGbool)

1515−boolAndDistinct = unsafeAggregateDistinct "bool_and"

1516−

1517−-- | >>> :{

1518−-- let

1519−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1520−-- expression = boolOrDistinct #col

1521−-- in printSQL expression

1522−-- :}

1523−-- bool_or(DISTINCT "col")

1524−boolOrDistinct

1525− :: Expression schema from 'Ungrouped params (nullity 'PGbool)

1526− -- ^ what to aggregate

1527− -> Expression schema from ('Grouped bys) params (nullity 'PGbool)

1528−boolOrDistinct = unsafeAggregateDistinct "bool_or"

1529−

1530−-- | A special aggregation that does not require an input

1531−--

1532−-- >>> printSQL countStar

1533−-- count(*)

1534−countStar

1535− :: Expression schema from ('Grouped bys) params ('NotNull 'PGint8)

1536−countStar = UnsafeExpression $ "count(*)"

1537−

1538−-- | >>> :{

1539−-- let

1540−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1541−-- expression = count #col

1542−-- in printSQL expression

1543−-- :}

1544−-- count("col")

1545−count

1546− :: Expression schema from 'Ungrouped params ty

1547− -- ^ what to count

1548− -> Expression schema from ('Grouped bys) params ('NotNull 'PGint8)

1549−count = unsafeAggregate "count"

1550−

1551−-- | >>> :{

1552−-- let

1553−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1554−-- expression = countDistinct #col

1555−-- in printSQL expression

1556−-- :}

1557−-- count(DISTINCT "col")

1558−countDistinct

1559− :: Expression schema from 'Ungrouped params ty

1560− -- ^ what to count

1561− -> Expression schema from ('Grouped bys) params ('NotNull 'PGint8)

1562−countDistinct = unsafeAggregateDistinct "count"

1563−

1564−-- | synonym for `boolAnd`

1565−--

1566−-- >>> :{

1567−-- let

1568−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1569−-- expression = every #col

1570−-- in printSQL expression

1571−-- :}

1572−-- every("col")

1573−every

1574− :: Expression schema from 'Ungrouped params (nullity 'PGbool)

1575− -- ^ what to aggregate

1576− -> Expression schema from ('Grouped bys) params (nullity 'PGbool)

1577−every = unsafeAggregate "every"

1578−

1579−-- | synonym for `boolAndDistinct`

1580−--

1581−-- >>> :{

1582−-- let

1583−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1584−-- expression = everyDistinct #col

1585−-- in printSQL expression

1586−-- :}

1587−-- every(DISTINCT "col")

1588−everyDistinct

1589− :: Expression schema from 'Ungrouped params (nullity 'PGbool)

1590− -- ^ what to aggregate

1591− -> Expression schema from ('Grouped bys) params (nullity 'PGbool)

1592−everyDistinct = unsafeAggregateDistinct "every"

1593−

1594−-- | minimum and maximum aggregation

1595−max_, min_, maxDistinct, minDistinct

1596− :: Expression schema from 'Ungrouped params (nullity ty)

1597− -- ^ what to aggregate

1598− -> Expression schema from ('Grouped bys) params (nullity ty)

1599−max_ = unsafeAggregate "max"

1600−min_ = unsafeAggregate "min"

1601−maxDistinct = unsafeAggregateDistinct "max"

1602−minDistinct = unsafeAggregateDistinct "min"

1603−

1604−{-----------------------------------------

1605−type expressions

1606−-----------------------------------------}

1607−

1608−-- | `TypeExpression`s are used in `cast`s and `createTable` commands.

1609−newtype TypeExpression (schema :: SchemaType) (ty :: NullityType)

1610− = UnsafeTypeExpression { renderTypeExpression :: ByteString }

1611− deriving (GHC.Generic,Show,Eq,Ord,NFData)

1612−

1613−-- | The enum or composite type in a `Typedef` can be expressed by its alias.

1614−typedef

1615− :: Has alias schema ('Typedef ty)

1616− => Alias alias

1617− -> TypeExpression schema (nullity ty)

1618−typedef = UnsafeTypeExpression . renderAlias

1619−

1620−-- | The composite type corresponding to a `Table` definition can be expressed

1621−-- by its alias.

1622−typetable

1623− :: Has alias schema ('Table tab)

1624− => Alias alias

1625− -> TypeExpression schema (nullity ('PGcomposite (TableToRow tab)))

1626−typetable = UnsafeTypeExpression . renderAlias

1627−

1628−-- | The composite type corresponding to a `View` definition can be expressed

1629−-- by its alias.

1630−typeview

1631− :: Has alias schema ('View view)

1632− => Alias alias

1633− -> TypeExpression schema (nullity ('PGcomposite view))

1634−typeview = UnsafeTypeExpression . renderAlias

1635−

1636−-- | logical Boolean (true/false)

1637−bool :: TypeExpression schema (nullity 'PGbool)

1638−bool = UnsafeTypeExpression "bool"

1639−-- | signed two-byte integer

1640−int2, smallint :: TypeExpression schema (nullity 'PGint2)

1641−int2 = UnsafeTypeExpression "int2"

1642−smallint = UnsafeTypeExpression "smallint"

1643−-- | signed four-byte integer

1644−int4, int, integer :: TypeExpression schema (nullity 'PGint4)

1645−int4 = UnsafeTypeExpression "int4"

1646−int = UnsafeTypeExpression "int"

1647−integer = UnsafeTypeExpression "integer"

1648−-- | signed eight-byte integer

1649−int8, bigint :: TypeExpression schema (nullity 'PGint8)

1650−int8 = UnsafeTypeExpression "int8"

1651−bigint = UnsafeTypeExpression "bigint"

1652−-- | arbitrary precision numeric type

1653−numeric :: TypeExpression schema (nullity 'PGnumeric)

1654−numeric = UnsafeTypeExpression "numeric"

1655−-- | single precision floating-point number (4 bytes)

1656−float4, real :: TypeExpression schema (nullity 'PGfloat4)

1657−float4 = UnsafeTypeExpression "float4"

1658−real = UnsafeTypeExpression "real"

1659−-- | double precision floating-point number (8 bytes)

1660−float8, doublePrecision :: TypeExpression schema (nullity 'PGfloat8)

1661−float8 = UnsafeTypeExpression "float8"

1662−doublePrecision = UnsafeTypeExpression "double precision"

1663−-- | variable-length character string

1664−text :: TypeExpression schema (nullity 'PGtext)

1665−text = UnsafeTypeExpression "text"

1666−-- | fixed-length character string

1667−char, character

1668− :: forall n schema nullity. (KnownNat n, 1 <= n)

1669− => TypeExpression schema (nullity ('PGchar n))

1670−char = UnsafeTypeExpression $ "char(" <> renderNat @n <> ")"

1671−character = UnsafeTypeExpression $ "character(" <> renderNat @n <> ")"

1672−-- | variable-length character string

1673−varchar, characterVarying

1674− :: forall n schema nullity. (KnownNat n, 1 <= n)

1675− => TypeExpression schema (nullity ('PGvarchar n))

1676−varchar = UnsafeTypeExpression $ "varchar(" <> renderNat @n <> ")"

1677−characterVarying = UnsafeTypeExpression $

1678− "character varying(" <> renderNat @n <> ")"

1679−-- | binary data ("byte array")

1680−bytea :: TypeExpression schema (nullity 'PGbytea)

1681−bytea = UnsafeTypeExpression "bytea"

1682−-- | date and time (no time zone)

1683−timestamp :: TypeExpression schema (nullity 'PGtimestamp)

1684−timestamp = UnsafeTypeExpression "timestamp"

1685−-- | date and time, including time zone

1686−timestampWithTimeZone :: TypeExpression schema (nullity 'PGtimestamptz)

1687−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"

1688−-- | calendar date (year, month, day)

1689−date :: TypeExpression schema (nullity 'PGdate)

1690−date = UnsafeTypeExpression "date"

1691−-- | time of day (no time zone)

1692−time :: TypeExpression schema (nullity 'PGtime)

1693−time = UnsafeTypeExpression "time"

1694−-- | time of day, including time zone

1695−timeWithTimeZone :: TypeExpression schema (nullity 'PGtimetz)

1696−timeWithTimeZone = UnsafeTypeExpression "time with time zone"

1697−-- | time span

1698−interval :: TypeExpression schema (nullity 'PGinterval)

1699−interval = UnsafeTypeExpression "interval"

1700−-- | universally unique identifier

1701−uuid :: TypeExpression schema (nullity 'PGuuid)

1702−uuid = UnsafeTypeExpression "uuid"

1703−-- | IPv4 or IPv6 host address

1704−inet :: TypeExpression schema (nullity 'PGinet)

1705−inet = UnsafeTypeExpression "inet"

1706−-- | textual JSON data

1707−json :: TypeExpression schema (nullity 'PGjson)

1708−json = UnsafeTypeExpression "json"

1709−-- | binary JSON data, decomposed

1710−jsonb :: TypeExpression schema (nullity 'PGjsonb)

1711−jsonb = UnsafeTypeExpression "jsonb"

1712−-- | variable length array

1713−vararray

1714− :: TypeExpression schema pg

1715− -> TypeExpression schema (nullity ('PGvararray pg))

1716−vararray ty = UnsafeTypeExpression $ renderTypeExpression ty <> "[]"

1717−-- | fixed length array

1718−--

1719−-- >>> renderTypeExpression (fixarray @2 json)

1720−-- "json[2]"

1721−fixarray

1722− :: forall n schema nullity pg. KnownNat n

1723− => TypeExpression schema pg

1724− -> TypeExpression schema (nullity ('PGfixarray n pg))

1725−fixarray ty = UnsafeTypeExpression $

1726− renderTypeExpression ty <> "[" <> renderNat @n <> "]"

1727−

1728−-- | `pgtype` is a demoted version of a `PGType`

1729−class PGTyped schema (ty :: NullityType) where

1730− pgtype :: TypeExpression schema ty

1731−instance PGTyped schema (nullity 'PGbool) where pgtype = bool

1732−instance PGTyped schema (nullity 'PGint2) where pgtype = int2

1733−instance PGTyped schema (nullity 'PGint4) where pgtype = int4

1734−instance PGTyped schema (nullity 'PGint8) where pgtype = int8

1735−instance PGTyped schema (nullity 'PGnumeric) where pgtype = numeric

1736−instance PGTyped schema (nullity 'PGfloat4) where pgtype = float4

1737−instance PGTyped schema (nullity 'PGfloat8) where pgtype = float8

1738−instance PGTyped schema (nullity 'PGtext) where pgtype = text

1739−instance (KnownNat n, 1 <= n)

1740− => PGTyped schema (nullity ('PGchar n)) where pgtype = char @n

1741−instance (KnownNat n, 1 <= n)

1742− => PGTyped schema (nullity ('PGvarchar n)) where pgtype = varchar @n

1743−instance PGTyped schema (nullity 'PGbytea) where pgtype = bytea

1744−instance PGTyped schema (nullity 'PGtimestamp) where pgtype = timestamp

1745−instance PGTyped schema (nullity 'PGtimestamptz) where pgtype = timestampWithTimeZone

1746−instance PGTyped schema (nullity 'PGdate) where pgtype = date

1747−instance PGTyped schema (nullity 'PGtime) where pgtype = time

1748−instance PGTyped schema (nullity 'PGtimetz) where pgtype = timeWithTimeZone

1749−instance PGTyped schema (nullity 'PGinterval) where pgtype = interval

1750−instance PGTyped schema (nullity 'PGuuid) where pgtype = uuid

1751−instance PGTyped schema (nullity 'PGjson) where pgtype = json

1752−instance PGTyped schema (nullity 'PGjsonb) where pgtype = jsonb

1753−instance PGTyped schema ty

1754− => PGTyped schema (nullity ('PGvararray ty)) where

1755− pgtype = vararray (pgtype @schema @ty)

1756−instance (KnownNat n, PGTyped schema ty)

1757− => PGTyped schema (nullity ('PGfixarray n ty)) where

1758− pgtype = fixarray @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+399−321

@@ -11,82 +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+ -- * Clauses

46+ , Optional (..)

47+ , QueryClause (..)

48+ , pattern Values_

49+ , ReturningClause (..)

50+ , pattern Returning_

51+ , ConflictClause (..)

52+ , ConflictTarget (..)

53+ , ConflictAction (..)

54+ , UsingClause (..)

4555 ) where

4656

4757import Control.DeepSeq

4858import Data.ByteString hiding (foldr)

49−import Data.Monoid

59+import Data.Kind (Type)

5060

5161import qualified Generics.SOP as SOP

5262import qualified GHC.Generics as GHC

5363

64+import Squeal.PostgreSQL.Alias

5465import Squeal.PostgreSQL.Expression

66+import Squeal.PostgreSQL.Expression.Logic

67+import Squeal.PostgreSQL.List

68+import Squeal.PostgreSQL.PG

5569import Squeal.PostgreSQL.Render

5670import Squeal.PostgreSQL.Query

5771import Squeal.PostgreSQL.Schema

5872

73+-- $setup

74+-- >>> import Squeal.PostgreSQL

75+-- >>> import Data.Int

76+-- >>> import Data.Time

77+

5978{- |

6079A `Manipulation` is a statement which may modify data in the database,

61−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.

6281A `Query` is also considered a `Manipulation` even though it does not modify data.

6382

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+

64125simple insert:

65126

127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]

128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

66129>>> :{

67130let

68− manipulation :: Manipulation

69− '[ "tab" ::: 'Table ('[] :=>

70− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

71− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[] '[]

131+ manipulation :: Manipulation_ (Public Schema) () ()

72132 manipulation =

73− insertRow_ #tab (Set 2 `as` #col1 :* Default `as` #col2)

133+ insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))

74134in printSQL manipulation

75135:}

76136INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)

77137

78138parameterized insert:

79139

140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

80142>>> :{

81143let

82− manipulation :: Manipulation

83− '[ "tab" ::: 'Table ('[] :=>

84− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

85− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

86− '[ 'NotNull 'PGint4, 'NotNull 'PGint4 ] '[]

144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()

87145 manipulation =

88− insertRow_ #tab

89− (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2)

146+ insertInto_ #tab (Values_ (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2))

90147in printSQL manipulation

91148:}

92149INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))

@@ -95,71 +152,48 @@ returning insert:

95152

96153>>> :{

97154let

98− manipulation :: Manipulation

99− '[ "tab" ::: 'Table ('[] :=>

100− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

101− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[]

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

155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)

103156 manipulation =

104− insertRow #tab (Set 2 `as` #col1 :* Default `as` #col2)

157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))

105158 OnConflictDoRaise (Returning (#col1 `as` #fromOnly))

106159in printSQL manipulation

107160:}

108−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"

109162

110163upsert:

111164

165+>>> type CustomersColumns = '["name" ::: 'NoDef :=> 'NotNull 'PGtext, "email" ::: 'NoDef :=> 'NotNull 'PGtext]

166+>>> type CustomersConstraints = '["uq" ::: 'Unique '["name"]]

167+>>> type CustomersSchema = '["customers" ::: 'Table (CustomersConstraints :=> CustomersColumns)]

112168>>> :{

113169let

114− manipulation :: Manipulation

115− '[ "tab" ::: 'Table ('[] :=>

116− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

117− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

118− '[] '[ "sum" ::: 'NotNull 'PGint4]

170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()

119171 manipulation =

120− insertRows #tab

121− (Set 2 `as` #col1 :* Set 4 `as` #col2)

122− [Set 6 `as` #col1 :* Set 8 `as` #col2]

123− (OnConflictDoUpdate

124− (Set 2 `as` #col1 :* Same `as` #col2)

125− [#col1 .== #col2])

126− (Returning $ (#col1 + #col2) `as` #sum)

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)

127177in printSQL manipulation

128178:}

129−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"))

130180

131181query insert:

132182

133183>>> :{

134184let

135− manipulation :: Manipulation

136− '[ "tab" ::: 'Table ('[] :=>

137− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

138− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

139− ])

140− , "other_tab" ::: 'Table ('[] :=>

141− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

142− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

143− ])

144− ] '[] '[]

145− manipulation =

146− insertQuery_ #tab

147− (selectStar (from (table (#other_tab `as` #t))))

185+ manipulation :: Manipulation_ (Public Schema) () ()

186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))

148187in printSQL manipulation

149188:}

150−INSERT INTO "tab" SELECT * FROM "other_tab" AS "t"

189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"

151190

152191update:

153192

154193>>> :{

155194let

156− manipulation :: Manipulation

157− '[ "tab" ::: 'Table ('[] :=>

158− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

159− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[] '[]

160− manipulation =

161− update_ #tab (Set 2 `as` #col1 :* Same `as` #col2)

162− (#col1 ./= #col2)

195+ manipulation :: Manipulation_ (Public Schema) () ()

196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)

163197in printSQL manipulation

164198:}

165199UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")

@@ -168,179 +202,178 @@ delete:

168202

169203>>> :{

170204let

171− manipulation :: Manipulation

172− '[ "tab" ::: 'Table ('[] :=>

173− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

174− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[]

175− '[ "col1" ::: 'NotNull 'PGint4

176− , "col2" ::: 'NotNull 'PGint4 ]

177− manipulation = deleteFrom #tab (#col1 .== #col2) ReturningStar

205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)

206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)

178207in printSQL manipulation

179208:}

180209DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *

181210

182−with manipulation:

211+delete and using clause:

183212

184−>>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

213+>>> :{

214+type Schema3 =

215+ '[ "tab" ::: 'Table ('[] :=> Columns)

216+ , "other_tab" ::: 'Table ('[] :=> Columns)

217+ , "third_tab" ::: 'Table ('[] :=> Columns) ]

218+:}

185219

186220>>> :{

187221let

188− manipulation :: Manipulation

189− '[ "products" ::: 'Table ProductsTable

190− , "products_deleted" ::: 'Table ProductsTable

191− ] '[ 'NotNull 'PGdate] '[]

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) ()

192239 manipulation = with

193− (deleteFrom #products (#date .< param @1) ReturningStar `as` #deleted_rows)

194− (insertQuery_ #products_deleted (selectStar (from (view (#deleted_rows `as` #t)))))

240+ (deleteFrom #products NoUsing (#date .< param @1) (Returning Star) `as` #del)

241+ (insertInto_ #products_deleted (Subquery (select Star (from (common #del)))))

195242in printSQL manipulation

196243:}

197−WITH "deleted_rows" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "deleted_rows" AS "t"

244+WITH "del" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "del" AS "del"

198245-}

199−

200−newtype Manipulation

201− (schema :: SchemaType)

202− (params :: [NullityType])

203− (columns :: RowType)

204− = UnsafeManipulation { renderManipulation :: ByteString }

205− deriving (GHC.Generic,Show,Eq,Ord,NFData)

206−instance RenderSQL (Manipulation schema params columns) where

207− renderSQL = renderManipulation

208−instance With Manipulation where

209− with Done manip = manip

210− with (cte :>> ctes) manip = UnsafeManipulation $

211− "WITH" <+> renderCommonTableExpressions renderManipulation cte ctes

212− <+> renderManipulation manip

246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where

247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)

213248

214249-- | Convert a `Query` into a `Manipulation`.

215250queryStatement

216− :: Query schema params columns

217− -> Manipulation schema params columns

218−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

219255

220256{-----------------------------------------

221257INSERT statements

222258-----------------------------------------}

223259

224−-- | Insert multiple rows.

225−--

226−-- When a table is created, it contains no data. The first thing to do

227−-- before a database can be of much use is to insert data. Data is

228−-- conceptually inserted one row at a time. Of course you can also insert

229−-- more than one row, but there is no way to insert less than one row.

230−-- Even if you know only some column values, a complete row must be created.

231−insertRows

232− :: ( SOP.SListI columns

233− , SOP.SListI results

234− , Has tab schema ('Table table)

235− , row ~ TableToRow table

236− , columns ~ TableToColumns table )

237− => Alias tab -- ^ table to insert into

238− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

239− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

240− -> ConflictClause schema table params

241− -- ^ what to do in case of constraint conflict

242− -> ReturningClause schema params row results -- ^ results to return

243− -> Manipulation schema params results

244−insertRows tab rw rws conflict returning = UnsafeManipulation $

245− "INSERT" <+> "INTO" <+> renderAlias tab

246− <+> parenthesized (renderCommaSeparated renderAliasPart rw)

247− <+> "VALUES"

248− <+> commaSeparated

249− ( parenthesized

250− . renderCommaSeparated renderColumnValuePart <$> rw:rws )

251− <> renderConflictClause conflict

252− <> renderReturningClause returning

253− where

254− renderAliasPart, renderColumnValuePart

255− :: Aliased (ColumnValue schema '[] params) ty -> ByteString

256− renderAliasPart (_ `As` name) = renderAlias name

257− renderColumnValuePart (value `As` _) = case value of

258− Default -> "DEFAULT"

259− Set expression -> renderExpression expression

260−

261−-- | Insert a single row.

262−insertRow

263− :: ( SOP.SListI columns

264− , SOP.SListI results

265− , Has tab schema ('Table table)

266− , row ~ TableToRow table

267− , columns ~ TableToColumns table )

268− => Alias tab -- ^ table to insert into

269− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

270− -> ConflictClause schema table params

271− -- ^ what to do in case of constraint conflict

272− -> ReturningClause schema params row results -- ^ results to return

273− -> Manipulation schema params results

274−insertRow tab rw = insertRows tab rw []

275−

276−-- | Insert multiple rows returning `Nil` and raising an error on conflicts.

277−insertRows_

278− :: ( SOP.SListI columns

279− , Has tab schema ('Table table)

280− , columns ~ TableToColumns table )

281− => Alias tab -- ^ table to insert into

282− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

283− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

284− -> Manipulation schema params '[]

285−insertRows_ tab rw rws =

286− insertRows tab rw rws OnConflictDoRaise (Returning Nil)

287−

288−-- | Insert a single row returning `Nil` and raising an error on conflicts.

289−insertRow_

290− :: ( SOP.SListI columns

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

291269 , Has tab schema ('Table table)

292− , columns ~ TableToColumns table )

293− => Alias tab -- ^ table to insert into

294− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

295− -> Manipulation schema params '[]

296−insertRow_ tab rw = insertRow tab rw OnConflictDoRaise (Returning Nil)

297−

298−-- | Insert a `Query`.

299−insertQuery

300− :: ( SOP.SListI columns

301− , SOP.SListI results

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

302292 , Has tab schema ('Table table)

293+ , columns ~ TableToColumns table

303294 , row ~ TableToRow table

304− , columns ~ TableToColumns table )

305− => Alias tab -- ^ table to insert into

306− -> Query schema params (TableToRow table)

307− -> ConflictClause schema table params

308− -- ^ what to do in case of constraint conflict

309− -> ReturningClause schema params row results -- ^ results to return

310− -> Manipulation schema params results

311−insertQuery tab query conflict returning = UnsafeManipulation $

312− "INSERT" <+> "INTO" <+> renderAlias tab

313− <+> renderQuery query

314− <> renderConflictClause conflict

315− <> renderReturningClause returning

316−

317−-- | Insert a `Query` returning `Nil` and raising an error on conflicts.

318−insertQuery_

319− :: ( SOP.SListI columns

320− , Has tab schema ('Table table)

321− , columns ~ TableToColumns table )

322− => Alias tab -- ^ table to insert into

323− -> Query schema params (TableToRow table)

324− -> Manipulation schema params '[]

325−insertQuery_ tab query =

326− insertQuery tab query OnConflictDoRaise (Returning Nil)

327−

328−-- | `ColumnValue`s are values to insert or update in a row.

329−-- `Same` updates with the same value.

330−-- `Default` inserts or updates with the @DEFAULT@ value.

331−-- `Set` sets a value to be an `Expression`, which can refer to

332−-- existing value in the row for an update.

333−data ColumnValue

334− (schema :: SchemaType)

335− (columns :: RowType)

336− (params :: [NullityType])

337− (ty :: ColumnType)

338− where

339− Same :: ColumnValue schema (column ': columns) params ty

340− Default :: ColumnValue schema columns params ('Def :=> ty)

341− Set

342− :: (forall table. Expression schema '[table ::: columns] 'Ungrouped params ty)

343− -> ColumnValue schema columns params (constraint :=> ty)

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

344377

345378-- | A `ReturningClause` computes and return value(s) based

346379-- on each row actually inserted, updated or deleted. This is primarily

@@ -348,74 +381,100 @@ data ColumnValue

348381-- serial sequence number. However, any expression using the table's columns

349382-- is allowed. Only rows that were successfully inserted or updated or

350383-- deleted will be returned. For example, if a row was locked

351−-- but not updated because an `OnConflictDoUpdate` condition was not satisfied,

352−-- the row will not be returned. `ReturningStar` will return all columns

353−-- 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

354387-- values are desired.

355−data ReturningClause

356− (schema :: SchemaType)

357− (params :: [NullityType])

358− (row0 :: RowType)

359− (row1 :: RowType)

360− where

361− ReturningStar

362− :: ReturningClause schema params row row

363− Returning

364− :: NP (Aliased (Expression schema '[table ::: row0] 'Ungrouped params)) row1

365− -> ReturningClause schema params row0 row1

366−

367−-- | Render a `ReturningClause`.

368−renderReturningClause

369− :: SOP.SListI results

370− => ReturningClause schema params columns results

371− -> ByteString

372−renderReturningClause = \case

373− ReturningStar -> " RETURNING *"

374− Returning Nil -> ""

375− Returning results -> " RETURNING"

376− <+> 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)

377403

378404-- | A `ConflictClause` specifies an action to perform upon a constraint

379405-- violation. `OnConflictDoRaise` will raise an error.

380−-- `OnConflictDoNothing` simply avoids inserting a row.

381−-- `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

382408-- proposed for insertion.

383−data ConflictClause

384− (schema :: SchemaType)

385− (table :: TableType)

386− (params :: [NullityType]) where

387− OnConflictDoRaise :: ConflictClause schema table params

388− OnConflictDoNothing :: ConflictClause schema table params

389− OnConflictDoUpdate

390− :: (row ~ TableToRow table, columns ~ TableToColumns table)

391− => NP (Aliased (ColumnValue schema row params)) columns

392− -> [Condition schema '[t ::: row] 'Ungrouped params]

393− -> ConflictClause schema table 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)

394417

395418-- | Render a `ConflictClause`.

396−renderConflictClause

397− :: SOP.SListI (TableToColumns table)

398− => ConflictClause schema table 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

399463 -> ByteString

400−renderConflictClause = \case

401− OnConflictDoRaise -> ""

402− OnConflictDoNothing -> " ON CONFLICT DO NOTHING"

403− OnConflictDoUpdate updates whs'

404− -> " ON CONFLICT DO UPDATE SET"

405− <+> renderCommaSeparatedMaybe renderUpdate updates

406− <> case whs' of

407− [] -> ""

408− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

409− where

410− renderUpdate

411− :: Aliased (ColumnValue schema columns params) column

412− -> Maybe ByteString

413− renderUpdate = \case

414− Same `As` _ -> Nothing

415− Default `As` column -> Just $

416− renderAlias column <+> "=" <+> "DEFAULT"

417− Set expression `As` column -> Just $

418− 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

419478

420479{-----------------------------------------

421480UPDATE statements

@@ -425,76 +484,95 @@ UPDATE statements

425484-- in all rows that satisfy the condition.

426485update

427486 :: ( SOP.SListI columns

428− , SOP.SListI results

487+ , SOP.SListI row1

488+ , Has sch schemas schema

429489 , Has tab schema ('Table table)

430− , row ~ TableToRow table

431− , columns ~ TableToColumns table )

432− => Alias tab -- ^ table to update

433− -> NP (Aliased (ColumnValue schema row 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

434496 -- ^ modified values to replace old values

435− -> (forall t. Condition schema '[t ::: row] 'Ungrouped params)

497+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row0]

436498 -- ^ condition under which to perform update on a row

437− -> ReturningClause schema params row results -- ^ results to return

438− -> Manipulation schema params results

499+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

500+ -> Manipulation commons schemas params row1

439501update tab columns wh returning = UnsafeManipulation $

440502 "UPDATE"

441− <+> renderAlias tab

503+ <+> renderSQL tab

442504 <+> "SET"

443− <+> renderCommaSeparatedMaybe renderUpdate columns

444− <+> "WHERE" <+> renderExpression wh

445− <> renderReturningClause returning

446− where

447− renderUpdate

448− :: Aliased (ColumnValue schema columns params) column

449− -> Maybe ByteString

450− renderUpdate = \case

451− Same `As` _ -> Nothing

452− Default `As` column -> Just $

453− renderAlias column <+> "=" <+> "DEFAULT"

454− Set expression `As` column -> Just $

455− renderAlias column <+> "=" <+> renderExpression expression

505+ <+> renderCommaSeparated renderUpdate columns

506+ <+> "WHERE" <+> renderSQL wh

507+ <> renderSQL returning

456508

457509-- | Update a row returning `Nil`.

458510update_

459511 :: ( SOP.SListI columns

512+ , Has sch schemas schema

460513 , Has tab schema ('Table table)

461514 , row ~ TableToRow table

462− , columns ~ TableToColumns table )

463− => Alias tab -- ^ table to update

464− -> NP (Aliased (ColumnValue schema row params)) columns

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

465520 -- ^ modified values to replace old values

466− -> (forall t. Condition schema '[t ::: row] 'Ungrouped params)

521+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

467522 -- ^ condition under which to perform update on a row

468− -> Manipulation schema params '[]

469−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)

470525

471526{-----------------------------------------

472527DELETE statements

473528-----------------------------------------}

474529

475−-- | 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.

476547deleteFrom

477− :: ( SOP.SListI results

548+ :: ( SOP.SListI row1

549+ , Has sch schemas schema

478550 , Has tab schema ('Table table)

479− , row ~ TableToRow table

551+ , row0 ~ TableToRow table

480552 , columns ~ TableToColumns table )

481− => Alias tab -- ^ table to delete from

482− -> Condition schema '[tab ::: row] '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)

483556 -- ^ condition under which to delete a row

484− -> ReturningClause schema params row results -- ^ results to return

485− -> Manipulation schema params results

486−deleteFrom tab wh returning = UnsafeManipulation $

487− "DELETE FROM" <+> renderAlias tab

488− <+> "WHERE" <+> renderExpression wh

489− <> 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

490567

491568-- | Delete rows returning `Nil`.

492569deleteFrom_

493− :: ( Has tab schema ('Table table)

570+ :: ( Has sch schemas schema

571+ , Has tab schema ('Table table)

494572 , row ~ TableToRow table

495573 , columns ~ TableToColumns table )

496− => Alias tab -- ^ table to delete from

497− -> (forall t. Condition schema '[t ::: row] 'Ungrouped params)

574+ => QualifiedAlias sch tab -- ^ table to delete from

575+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

498576 -- ^ condition under which to delete a row

499− -> Manipulation schema params '[]

500−deleteFrom_ tab wh = deleteFrom tab wh (Returning Nil)

577+ -> Manipulation commons schemas params '[]

578+deleteFrom_ tab wh = deleteFrom tab NoUsing wh (Returning_ Nil)

squeal-postgresql/src/Squeal/PostgreSQL/Migration.hs+339−187

@@ -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

@@ -29,228 +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

44+ , up = createTable #users

3945 ( serial `as` #id :*

40− (text & notNullable) `as` #name )

46+ notNullable text `as` #name )

4147 ( primaryKey #id `as` #pk_users )

42− , down = void . define $ dropTable #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

58+ , up = createTable #emails

5459 ( serial `as` #id :*

55− (int & notNullable) `as` #user_id :*

56− (text & nullable) `as` #email )

60+ notNullable int `as` #user_id :*

61+ nullable text `as` #email )

5762 ( primaryKey #id `as` #pk_emails :*

5863 foreignKey #user_id #users #id

5964 OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

60− , down = void . define $ dropTable #emails

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− -- * Migration table

143+ , Migratory (..)

144+ , Terminally (..)

145+ , terminally

146+ , pureMigration

109147 , MigrationsTable

110− , createMigrations

111− , insertMigration

112− , deleteMigration

113− , selectMigration

148+ , defaultMain

114149 ) where

115150

151+import Control.Category

116152import Control.Monad

117−import Control.Monad.Base

118−import Control.Monad.Trans.Control

119−import Data.Monoid

120−import Generics.SOP (K(..))

153+import Data.ByteString (ByteString)

154+import Data.Foldable (traverse_)

121155import Data.Function ((&))

156+import Data.List ((\\))

122157import Data.Text (Text)

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

123166

124−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

125182

126−-- | A `Migration` should contain an inverse pair of

127−-- `up` and `down` instructions and a unique `name`.

128−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

129187 { name :: Text -- ^ The `name` of a `Migration`.

130188 -- Each `name` in a `Migration` should be unique.

131− , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.

132− , 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

133260 }

134261

135−-- | Run `Migration`s by creating the `MigrationsTable`

136−-- if it does not exist and then in a transaction, for each each `Migration`

137−-- query to see if the `Migration` is executed. If not, then

138−-- execute the `Migration` and insert its row in the `MigrationsTable`.

139−migrateUp

140− :: MonadBaseControl IO io

141− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run

142− -> PQ

143− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

144− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

145− io ()

146−migrateUp migration =

147− define createMigrations

148− & pqBind okResult

149− & pqThen (transactionallySchema_ (upMigrations migration))

150− where

262+instance Migratory (Terminally PQ IO) where

151263

152− upMigrations

153− :: MonadBaseControl IO io

154− => AlignedList (Migration io) schema0 schema1

155− -> PQ

156− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

157− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

158− io ()

159− upMigrations = \case

160− Done -> return ()

161− step :>> steps -> upMigration step & pqThen (upMigrations steps)

162−

163− upMigration

164− :: MonadBase IO io

165− => Migration io schema0 schema1 -> PQ

166− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

167− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

168− io ()

169− upMigration step =

170− queryExecuted step

171− & pqBind (\ executed ->

172− if executed == 1 -- up step has already been executed

173− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

174− else

175− pqEmbed (up step) -- safely switch schemas

176− & pqThen (manipulateParams insertMigration (Only (name step)))

177− -- insert execution record

178− & pqBind okResult)

179−

180− queryExecuted

181− :: MonadBase IO io

182− => Migration io schema0 schema1 -> PQ

183− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

184− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

185− io Row

186− queryExecuted step = do

187− result <- runQueryParams selectMigration (Only (name step))

188− okResult result

189− ntuples result

190−

191−-- | Rewind `Migration`s by creating the `MigrationsTable`

192−-- if it does not exist and then in a transaction, for each each `Migration`

193−-- query to see if the `Migration` is executed. If it is, then

194−-- rewind the `Migration` and delete its row in the `MigrationsTable`.

195−migrateDown

196− :: MonadBaseControl IO io

197− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind

198− -> PQ

199− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

200− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

201− io ()

202−migrateDown migrations =

203− define createMigrations

204− & pqBind okResult

205− & pqThen (transactionallySchema_ (downMigrations migrations))

206− 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

207298

208− downMigrations

209− :: MonadBaseControl IO io

210− => AlignedList (Migration io) schema0 schema1 -> PQ

211− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

212− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

213− io ()

214− downMigrations = \case

215− Done -> return ()

216− step :>> steps -> downMigrations steps & pqThen (downMigration step)

217−

218− downMigration

219− :: MonadBase IO io

220− => Migration io schema0 schema1 -> PQ

221− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

222− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

223− io ()

224− downMigration step =

225− queryExecuted step

226− & pqBind (\ executed ->

227− if executed == 0 -- up step has not been executed

228− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

229− else

230− pqEmbed (down step) -- safely switch schemas

231− & pqThen (manipulateParams deleteMigration (Only (name step)))

232− -- delete execution record

233− & pqBind okResult)

234−

235− queryExecuted

236− :: MonadBase IO io

237− => Migration io schema0 schema1 -> PQ

238− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

239− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

240− io Row

241− queryExecuted step = do

242− result <- runQueryParams selectMigration (Only (name step))

243− okResult result

244− ntuples result

245−

246−okResult :: MonadBase IO io => K Result results -> PQ schema schema io ()

247−okResult result = do

248− status <- resultStatus result

249− when (not (status `elem` [CommandOk, TuplesOk])) $ do

250− errorMessageMaybe <- resultErrorMessage result

251− case errorMessageMaybe of

252− Nothing -> error "migrateDown: unknown error"

253− Just msg -> error ("migrationDown: " <> show msg)

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

305+

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

254324

255325-- | The `TableType` for a Squeal migration.

256326type MigrationsTable =

@@ -259,10 +329,19 @@ type MigrationsTable =

259329 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

260330 ]

261331

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+

262343-- | Creates a `MigrationsTable` if it does not already exist.

263−createMigrations

264− :: Has "schema_migrations" schema ('Table MigrationsTable)

265− => Definition schema schema

344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas

266345createMigrations =

267346 createTableIfNotExists #schema_migrations

268347 ( (text & notNullable) `as` #name :*

@@ -270,27 +349,100 @@ createMigrations =

270349 `as` #executed_at )

271350 ( unique #name `as` #migrations_unique_name )

272351

273−-- | Inserts a `Migration` into the `MigrationsTable`

274−insertMigration

275− :: Has "schema_migrations" schema ('Table MigrationsTable)

276− => Manipulation schema '[ 'NotNull 'PGtext] '[]

277−insertMigration = insertRow_ #schema_migrations

278− ( Set (param @1) `as` #name :*

279− Default `as` #executed_at )

280−

281−-- | Deletes a `Migration` from the `MigrationsTable`

282−deleteMigration

283− :: Has "schema_migrations" schema ('Table MigrationsTable)

284− => Manipulation schema '[ 'NotNull 'PGtext ] '[]

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) ()

285361deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

286362

287363-- | Selects a `Migration` from the `MigrationsTable`, returning

288−-- the time at which it was executed.

364+-- the time at which it was inserted.

289365selectMigration

290− :: Has "schema_migrations" schema ('Table MigrationsTable)

291− => Query schema '[ 'NotNull 'PGtext ]

292− '[ "executed_at" ::: 'NotNull 'PGtimestamptz ]

293−selectMigration = select

294− (#executed_at `as` #executed_at)

295− ( from (table (#schema_migrations `as` #m))

296− & 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+233−192

@@ -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

@@ -48,8 +49,6 @@ module Squeal.PostgreSQL.PQ

4849 , evalPQ

4950 , IndexedMonadTransPQ (..)

5051 , MonadPQ (..)

51− , PQRun

52− , pqliftWith

5352 -- * Results

5453 , LibPQ.Result

5554 , LibPQ.Row

@@ -65,26 +64,30 @@ module Squeal.PostgreSQL.PQ

6564 , resultErrorCode

6665 -- * Exceptions

6766 , SquealException (..)

67+ , PQState (..)

68+ , okResult

6869 , catchSqueal

6970 , handleSqueal

71+ , trySqueal

7072 ) where

7173

72−import Control.Exception.Lifted

73−import Control.Monad.Base

74+import Control.Exception (Exception, throw)

7475import Control.Monad.Except

7576import Control.Monad.Morph

76−import Control.Monad.Trans.Control

77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)

7778import Data.ByteString (ByteString)

7879import Data.Foldable

7980import Data.Function ((&))

81+import Data.Functor ((<&>))

8082import Data.Kind

81−import Data.Monoid

8283import Data.Text (pack, Text)

8384import Data.Traversable

8485import Generics.SOP

8586import PostgreSQL.Binary.Encoding (encodingBytes)

8687

88+import qualified Control.Monad.Fail as Fail

8789import qualified Database.PostgreSQL.LibPQ as LibPQ

90+import qualified PostgreSQL.Binary.Encoding as Encoding

8891

8992import Squeal.PostgreSQL.Binary

9093import Squeal.PostgreSQL.Definition

@@ -97,7 +100,6 @@ import Control.Monad.Trans.Identity

97100import Control.Monad.Trans.Reader

98101import Control.Monad.Trans.Maybe

99102import Control.Monad.Trans.Cont

100−import Control.Monad.Trans.List

101103

102104import qualified Control.Monad.Trans.State.Lazy as Lazy

103105import qualified Control.Monad.Trans.State.Strict as Strict

@@ -106,6 +108,9 @@ import qualified Control.Monad.Trans.Writer.Strict as Strict

106108import qualified Control.Monad.Trans.RWS.Lazy as Lazy

107109import qualified Control.Monad.Trans.RWS.Strict as Strict

108110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

109114{- | Makes a new connection to the database server.

110115

111116This function opens a new database connection using the parameters taken

@@ -132,22 +137,22 @@ Note that, for now, squeal doesn't offer any protection from connecting

132137with the wrong schema!

133138-}

134139connectdb

135− :: forall schema io

136− . MonadBase IO io

140+ :: forall schemas io

141+ . MonadIO io

137142 => ByteString -- ^ conninfo

138− -> io (K LibPQ.Connection schema)

139−connectdb = fmap K . liftBase . LibPQ.connectdb

143+ -> io (K LibPQ.Connection schemas)

144+connectdb = fmap K . liftIO . LibPQ.connectdb

140145

141146-- | Closes the connection to the server.

142−finish :: MonadBase IO io => K LibPQ.Connection schema -> io ()

143−finish = liftBase . LibPQ.finish . unK

147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()

148+finish = liftIO . LibPQ.finish . unK

144149

145150-- | Do `connectdb` and `finish` before and after a computation.

146151withConnection

147− :: forall schema0 schema1 io x

148− . MonadBaseControl IO io

152+ :: forall schemas0 schemas1 io x

153+ . MonadUnliftIO io

149154 => ByteString

150− -> PQ schema0 schema1 io x

155+ -> PQ schemas0 schemas1 io x

151156 -> io x

152157withConnection connString action = do

153158 K x <- bracket (connectdb connString) finish (unPQ action)

@@ -155,47 +160,47 @@ withConnection connString action = do

155160

156161-- | Safely `lowerConnection` to a smaller schema.

157162lowerConnection

158− :: K LibPQ.Connection (table ': schema)

159− -> K LibPQ.Connection schema

163+ :: K LibPQ.Connection (schema ': schemas)

164+ -> K LibPQ.Connection schemas

160165lowerConnection (K conn) = K conn

161166

162167-- | We keep track of the schema via an Atkey indexed state monad transformer,

163168-- `PQ`.

164169newtype PQ

165− (schema0 :: SchemaType)

166− (schema1 :: SchemaType)

170+ (schemas0 :: SchemasType)

171+ (schemas1 :: SchemasType)

167172 (m :: Type -> Type)

168173 (x :: Type) =

169− PQ { unPQ :: K LibPQ.Connection schema0 -> m (K x schema1) }

174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }

170175

171−instance Monad m => Functor (PQ schema0 schema1 m) where

176+instance Monad m => Functor (PQ schemas0 schemas1 m) where

172177 fmap f (PQ pq) = PQ $ \ conn -> do

173178 K x <- pq conn

174179 return $ K (f x)

175180

176−-- | Run a `PQ` and keep the result and the `Connection`.

181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.

177182runPQ

178183 :: Functor m

179− => PQ schema0 schema1 m x

180− -> K LibPQ.Connection schema0

181− -> m (x, K LibPQ.Connection schema1)

184+ => PQ schemas0 schemas1 m x

185+ -> K LibPQ.Connection schemas0

186+ -> m (x, K LibPQ.Connection schemas1)

182187runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

183188 -- K x <- pq conn

184189 -- return (x, K (unK conn))

185190

186−-- | Execute a `PQ` and discard the result but keep the `Connection`.

191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.

187192execPQ

188193 :: Functor m

189− => PQ schema0 schema1 m x

190− -> K LibPQ.Connection schema0

191− -> m (K LibPQ.Connection schema1)

194+ => PQ schemas0 schemas1 m x

195+ -> K LibPQ.Connection schemas0

196+ -> m (K LibPQ.Connection schemas1)

192197execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

193198

194−-- | Evaluate a `PQ` and discard the `Connection` but keep the result.

199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.

195200evalPQ

196201 :: Functor m

197− => PQ schema0 schema1 m x

198− -> K LibPQ.Connection schema0

202+ => PQ schemas0 schemas1 m x

203+ -> K LibPQ.Connection schemas0

199204 -> m x

200205evalPQ (PQ pq) conn = unK <$> pq conn

201206

@@ -203,60 +208,56 @@ evalPQ (PQ pq) conn = unK <$> pq conn

203208-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

204209-- An indexed monad transformer transforms a `Monad` into an indexed monad.

205210-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

206−-- support running `Definition`s using `define` and embedding a computation

207−-- in a larger schema using `pqEmbed`.

211+-- support running `Definition`s using `define`.

208212class IndexedMonadTransPQ pq where

209213

210214 -- | indexed analog of `<*>`

211215 pqAp

212216 :: Monad m

213− => pq schema0 schema1 m (x -> y)

214− -> pq schema1 schema2 m x

215− -> pq schema0 schema2 m y

217+ => pq schemas0 schemas1 m (x -> y)

218+ -> pq schemas1 schemas2 m x

219+ -> pq schemas0 schemas2 m y

216220

217221 -- | indexed analog of `join`

218222 pqJoin

219223 :: Monad m

220− => pq schema0 schema1 m (pq schema1 schema2 m y)

221− -> pq schema0 schema2 m y

224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)

225+ -> pq schemas0 schemas2 m y

222226 pqJoin pq = pq & pqBind id

223227

224228 -- | indexed analog of `=<<`

225229 pqBind

226230 :: Monad m

227− => (x -> pq schema1 schema2 m y)

228− -> pq schema0 schema1 m x

229− -> pq schema0 schema2 m y

231+ => (x -> pq schemas1 schemas2 m y)

232+ -> pq schemas0 schemas1 m x

233+ -> pq schemas0 schemas2 m y

230234

231235 -- | indexed analog of flipped `>>`

232236 pqThen

233237 :: Monad m

234− => pq schema1 schema2 m y

235− -> pq schema0 schema1 m x

236− -> pq schema0 schema2 m y

238+ => pq schemas1 schemas2 m y

239+ -> pq schemas0 schemas1 m x

240+ -> pq schemas0 schemas2 m y

237241 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

238242

239243 -- | indexed analog of `<=<`

240244 pqAndThen

241245 :: Monad m

242− => (y -> pq schema1 schema2 m z)

243− -> (x -> pq schema0 schema1 m y)

244− -> 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

245249 pqAndThen g f x = pqBind g (f x)

246250

247− -- | Safely embed a computation in a larger schema.

248− pqEmbed

249− :: Monad m

250− => pq schema0 schema1 m x

251− -> pq (table ': schema0) (table : schema1) m x

252−

253− -- | Run a `Definition` with `LibPQ.exec`, we expect that libpq obeys the law

251+ -- | Run a `Definition` with `LibPQ.exec`.

254252 --

255− -- @define statement1 & pqThen (define statement2) = define (statement1 >>> statement2)@

253+ -- It should be functorial in effect.

254+ --

255+ -- @define id = return ()@

256+ -- @define (statement1 >>> statement2) = define statement1 & pqThen (define statement2)@

256257 define

257− :: MonadBase IO io

258− => Definition schema0 schema1

259− -> pq schema0 schema1 io (K LibPQ.Result '[])

258+ :: MonadIO io

259+ => Definition schemas0 schemas1

260+ -> pq schemas0 schemas1 io ()

260261

261262instance IndexedMonadTransPQ PQ where

262263

@@ -269,26 +270,26 @@ instance IndexedMonadTransPQ PQ where

269270 K x' <- x conn

270271 unPQ (f x') (K (unK conn))

271272

272− pqEmbed (PQ pq) = PQ $ \ (K conn) -> do

273− K x <- pq (K conn)

274− return $ K x

275−

276273 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

277− resultMaybe <- liftBase $ LibPQ.exec conn q

274+ resultMaybe <- liftIO $ LibPQ.exec conn q

278275 case resultMaybe of

279276 Nothing -> throw $ ResultException

280277 "define: LibPQ.exec returned no results"

281− Just result -> return $ K (K result)

278+ Just result -> K <$> okResult_ result

282279

283−{- | `MonadPQ` is an `mtl` style constraint, similar to

284−`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

285282

286283* `manipulateParams` runs a `Manipulation` with params from a type

287284 with a `ToParams` constraint. It calls `LibPQ.execParams` and

288285 doesn't afraid of anything.

289286

287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.

288+

290289* `manipulate` is like `manipulateParams` for a parameter-free statement.

291290

291+* `manipulate_` is like `manipulate` for a returning-free statement.

292+

292293* `runQueryParams` is like `manipulateParams` for query statements.

293294

294295* `runQuery` is like `runQueryParams` for a parameter-free statement.

@@ -302,11 +303,11 @@ instance IndexedMonadTransPQ PQ where

302303* `forPrepared` is a flipped `traversePrepared`

303304

304305* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

305− containers and returns unit.

306+ containers for a returning-free statement.

306307

307308* `forPrepared_` is a flipped `traversePrepared_`.

308309

309−* `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

310311 into your monad.

311312

312313To define an instance, you can minimally define only `manipulateParams`,

@@ -314,140 +315,172 @@ To define an instance, you can minimally define only `manipulateParams`,

314315a default instance.

315316

316317-}

317−class Monad pq => MonadPQ schema pq | pq -> schema where

318+class Monad pq => MonadPQ schemas pq | pq -> schemas where

318319 manipulateParams

319− :: ToParams x params

320− => Manipulation schema params ys

321− -- ^ `insertRows`, `update` or `deleteFrom`

320+ :: (ToParams x params, All OidOfParam params)

321+ => Manipulation '[] schemas params ys

322+ -- ^ `insertInto`, `update` or `deleteFrom`

322323 -> x -> pq (K LibPQ.Result ys)

323324 default manipulateParams

324− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

325− => ToParams x params

326− => Manipulation schema params ys

327− -- ^ `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`

328329 -> x -> pq (K LibPQ.Result ys)

329330 manipulateParams manipulation params = lift $

330331 manipulateParams manipulation params

331332

332− 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)

333341 manipulate statement = manipulateParams statement ()

334342

343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()

344+ manipulate_ = void . manipulate

345+

335346 runQueryParams

336− :: ToParams x params

337− => Query schema params ys

347+ :: (ToParams x params, All OidOfParam params)

348+ => Query '[] '[] schemas params ys

338349 -- ^ `select` and friends

339350 -> x -> pq (K LibPQ.Result ys)

340351 runQueryParams = manipulateParams . queryStatement

341352

342353 runQuery

343− :: Query schema '[] ys

354+ :: Query '[] '[] schemas '[] ys

344355 -- ^ `select` and friends

345356 -> pq (K LibPQ.Result ys)

346357 runQuery q = runQueryParams q ()

347358

348359 traversePrepared

349− :: (ToParams x params, Traversable list)

350− => Manipulation schema params ys

351− -- ^ `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

352363 -> list x -> pq (list (K LibPQ.Result ys))

353364 default traversePrepared

354− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

355− => (ToParams x params, Traversable list)

356− => 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))

357368 traversePrepared manipulation params = lift $

358369 traversePrepared manipulation params

359370

360371 forPrepared

361− :: (ToParams x params, Traversable list)

372+ :: (ToParams x params, Traversable list, All OidOfParam params)

362373 => list x

363− -> Manipulation schema params ys

364− -- ^ `insertRows`, `update` or `deleteFrom`

374+ -> Manipulation '[] schemas params ys

375+ -- ^ `insertInto`, `update` or `deleteFrom`

365376 -> pq (list (K LibPQ.Result ys))

366377 forPrepared = flip traversePrepared

367378

368379 traversePrepared_

369− :: (ToParams x params, Foldable list)

370− => Manipulation schema params '[]

371− -- ^ `insertRows`, `update` or `deleteFrom`

380+ :: (ToParams x params, Foldable list, All OidOfParam params)

381+ => Manipulation '[] schemas params '[]

382+ -- ^ `insertInto`, `update` or `deleteFrom`

372383 -> list x -> pq ()

373384 default traversePrepared_

374− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

375− => (ToParams x params, Foldable list)

376− => Manipulation schema params '[]

377− -- ^ `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`

378389 -> list x -> pq ()

379390 traversePrepared_ manipulation params = lift $

380391 traversePrepared_ manipulation params

381392

382393 forPrepared_

383− :: (ToParams x params, Foldable list)

394+ :: (ToParams x params, Foldable list, All OidOfParam params)

384395 => list x

385− -> Manipulation schema params '[]

386− -- ^ `insertRows`, `update` or `deleteFrom`

396+ -> Manipulation '[] schemas params '[]

397+ -- ^ `insertInto`, `update` or `deleteFrom`

387398 -> pq ()

388399 forPrepared_ = flip traversePrepared_

389400

390401 liftPQ :: (LibPQ.Connection -> IO a) -> pq a

391402 default liftPQ

392− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

393404 => (LibPQ.Connection -> IO a) -> pq a

394405 liftPQ = lift . liftPQ

395406

396−instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)

397− => MonadPQ schema (PQ schema0 schema1 io) where

407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)

408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where

398409

399410 manipulateParams

400− (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =

411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =

401412 PQ $ \ (K conn) -> do

402413 let

403− toParam' encoding =

404− (LibPQ.invalidOid, encodingBytes encoding, LibPQ.Binary)

405− 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

406425 q' = q <> ";"

407− resultMaybe <- liftBase $ LibPQ.execParams conn q' params' LibPQ.Binary

426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary

408427 case resultMaybe of

409428 Nothing -> throw $ ResultException

410429 "manipulateParams: LibPQ.execParams returned no results"

411430 Just result -> do

412− tryResult result

431+ okResult_ result

413432 return $ K (K result)

414433

415434 traversePrepared

416− (UnsafeManipulation q :: Manipulation schema xs ys) (list :: list x) =

417− PQ $ \ (K conn) -> liftBase $ do

418− let temp = "temporary_statement"

419− 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')

420446 case prepResultMaybe of

421447 Nothing -> throw $ ResultException

422448 "traversePrepared: LibPQ.prepare returned no results"

423− Just prepResult -> tryResult prepResult

449+ Just prepResult -> okResult_ prepResult

424450 results <- for list $ \ params -> do

425451 let

426− toParam' encoding = (encodingBytes encoding,LibPQ.Binary)

452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

427453 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

428454 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

429455 case resultMaybe of

430456 Nothing -> throw $ ResultException

431457 "traversePrepared: LibPQ.execParams returned no results"

432458 Just result -> do

433− tryResult result

459+ okResult_ result

434460 return $ K result

435461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

436462 case deallocResultMaybe of

437463 Nothing -> throw $ ResultException

438464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

439− Just deallocResult -> tryResult deallocResult

465+ Just deallocResult -> okResult_ deallocResult

440466 return (K results)

441467

442468 traversePrepared_

443− (UnsafeManipulation q :: Manipulation schema xs '[]) (list :: list x) =

444− PQ $ \ (K conn) -> liftBase $ do

445− let temp = "temporary_statement"

446− 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')

447480 case prepResultMaybe of

448481 Nothing -> throw $ ResultException

449482 "traversePrepared_: LibPQ.prepare returned no results"

450− Just prepResult -> tryResult prepResult

483+ Just prepResult -> okResult_ prepResult

451484 for_ list $ \ params -> do

452485 let

453486 toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

@@ -456,83 +489,79 @@ instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)

456489 case resultMaybe of

457490 Nothing -> throw $ ResultException

458491 "traversePrepared_: LibPQ.execParams returned no results"

459− Just result -> tryResult result

492+ Just result -> okResult_ result

460493 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

461494 case deallocResultMaybe of

462495 Nothing -> throw $ ResultException

463496 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

464− Just deallocResult -> tryResult deallocResult

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

509−

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)

542+instance (MonadIO m, schema0 ~ schema1)

543+ => MonadIO (PQ schema0 schema1 m) where

544+ liftIO = lift . liftIO

518545

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

537566 when (numRows < r) $ throw $ ResultException $

538567 "getRow: expected at least " <> pack (show r) <> "rows but only saw "

@@ -550,13 +579,13 @@ getRow r (K result :: K LibPQ.Result columns) = liftBase $ do

550579-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,

551580-- otherwise returning the row along with the next row number.

552581nextRow

553− :: (FromRow columns y, MonadBase IO io)

582+ :: (FromRow columns y, MonadIO io)

554583 => LibPQ.Row -- ^ total number of rows

555584 -> K LibPQ.Result columns -- ^ result

556585 -> LibPQ.Row -- ^ row number

557586 -> io (Maybe (LibPQ.Row,y))

558587nextRow total (K result :: K LibPQ.Result columns) r

559− = liftBase $ if r >= total then return Nothing else do

588+ = liftIO $ if r >= total then return Nothing else do

560589 let len = fromIntegral (lengthSList (Proxy @columns))

561590 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

562591 case fromList row' of

@@ -567,10 +596,10 @@ nextRow total (K result :: K LibPQ.Result columns) r

567596

568597-- | Get all rows from a `LibPQ.Result`.

569598getRows

570− :: (FromRow columns y, MonadBase IO io)

599+ :: (FromRow columns y, MonadIO io)

571600 => K LibPQ.Result columns -- ^ result

572601 -> io [y]

573−getRows (K result :: K LibPQ.Result columns) = liftBase $ do

602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do

574603 let len = fromIntegral (lengthSList (Proxy @columns))

575604 numRows <- LibPQ.ntuples result

576605 for [0 .. numRows - 1] $ \ r -> do

@@ -583,10 +612,10 @@ getRows (K result :: K LibPQ.Result columns) = liftBase $ do

583612

584613-- | Get the first row if possible from a `LibPQ.Result`.

585614firstRow

586− :: (FromRow columns y, MonadBase IO io)

615+ :: (FromRow columns y, MonadIO io)

587616 => K LibPQ.Result columns -- ^ result

588617 -> io (Maybe y)

589−firstRow (K result :: K LibPQ.Result columns) = liftBase $ do

618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do

590619 numRows <- LibPQ.ntuples result

591620 if numRows <= 0 then return Nothing else do

592621 let len = fromIntegral (lengthSList (Proxy @columns))

@@ -599,23 +628,23 @@ firstRow (K result :: K LibPQ.Result columns) = liftBase $ do

599628

600629-- | Lifts actions on results from @LibPQ@.

601630liftResult

602− :: MonadBase IO io

631+ :: MonadIO io

603632 => (LibPQ.Result -> IO x)

604633 -> K LibPQ.Result results -> io x

605−liftResult f (K result) = liftBase $ f result

634+liftResult f (K result) = liftIO $ f result

606635

607636-- | Returns the number of rows (tuples) in the query result.

608−ntuples :: MonadBase IO io => K LibPQ.Result columns -> io LibPQ.Row

637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row

609638ntuples = liftResult LibPQ.ntuples

610639

611640-- | Returns the result status of the command.

612−resultStatus :: MonadBase IO io => K LibPQ.Result results -> io LibPQ.ExecStatus

641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus

613642resultStatus = liftResult LibPQ.resultStatus

614643

615644-- | Returns the error message most recently generated by an operation

616645-- on the connection.

617646resultErrorMessage

618− :: MonadBase IO io => K LibPQ.Result results -> io (Maybe ByteString)

647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)

619648resultErrorMessage = liftResult LibPQ.resultErrorMessage

620649

621650-- | Returns the error code most recently generated by an operation

@@ -623,29 +652,29 @@ resultErrorMessage = liftResult LibPQ.resultErrorMessage

623652--

624653-- https://www.postgresql.org/docs/current/static/errcodes-appendix.html

625654resultErrorCode

626− :: MonadBase IO io

655+ :: MonadIO io

627656 => K LibPQ.Result results

628657 -> io (Maybe ByteString)

629658resultErrorCode = liftResult (flip LibPQ.resultErrorField LibPQ.DiagSqlstate)

630659

631−-- | `Exception`s that can be thrown by Squeal.

632−data SquealException

633− = PQException

660+-- | the state of LibPQ

661+data PQState = PQState

634662 { sqlExecStatus :: LibPQ.ExecStatus

635663 , sqlStateCode :: Maybe ByteString

636664 -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html

637665 , sqlErrorMessage :: Maybe ByteString

638− }

666+ } deriving (Eq, Show)

667+

668+-- | `Exception`s that can be thrown by Squeal.

669+data SquealException

670+ = PQException PQState

639671 | ResultException Text

640672 | ParseException Text

641673 deriving (Eq, Show)

642674instance Exception SquealException

643675

644−tryResult

645− :: MonadBase IO io

646− => LibPQ.Result

647− -> io ()

648−tryResult result = liftBase $ do

676+okResult_ :: MonadIO io => LibPQ.Result -> io ()

677+okResult_ result = liftIO $ do

649678 status <- LibPQ.resultStatus result

650679 case status of

651680 LibPQ.CommandOk -> return ()

@@ -653,11 +682,16 @@ tryResult result = liftBase $ do

653682 _ -> do

654683 stateCode <- LibPQ.resultErrorField result LibPQ.DiagSqlstate

655684 msg <- LibPQ.resultErrorMessage result

656− throw $ PQException status stateCode msg

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

657691

658692-- | Catch `SquealException`s.

659693catchSqueal

660− :: MonadBaseControl IO io

694+ :: MonadUnliftIO io

661695 => io a

662696 -> (SquealException -> io a) -- ^ handler

663697 -> io a

@@ -665,7 +699,14 @@ catchSqueal = catch

665699

666700-- | Handle `SquealException`s.

667701handleSqueal

668− :: MonadBaseControl IO io

702+ :: MonadUnliftIO io

669703 => (SquealException -> io a) -- ^ handler

670704 -> io a -> io a

671705handleSqueal = 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+73−104

@@ -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

@@ -22,55 +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−

46−Typical use case would be to create your pool using `createConnectionPool` and run anything that requires the pool connection with it.

47−

48−Here's a simplified example:

49−

50−> type Schema = '[ "tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint2])]

51−>

52−> someQuery :: Manipulation Schema '[ 'NotNull 'PGint2] '[]

53−> someQuery = insertRow #tab

54−> (Set (param @1) `As` #col :* Nil)

55−> OnConflictDoNothing (Returning Nil)

56−>

57−> insertOne :: (MonadBaseControl IO m, MonadPQ Schema m) => m ()

58−> insertOne = void $ manipulateParams someQuery . Only $ (1 :: Int16)

59−>

60−> insertOneInPool :: ByteString -> IO ()

61−> insertOneInPool connectionString = do

62−> pool <- createConnectionPool connectionString 1 0.5 10

63−> liftIO $ runPoolPQ (insertOne) pool

64−

65−-}

66−newtype PoolPQ (schema :: SchemaType) m x =

67− PoolPQ { runPoolPQ :: Pool (K Connection schema) -> m x }

68− deriving Functor

6961

7062-- | Create a striped pool of connections.

7163-- 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.

7264createConnectionPool

73− :: MonadBase IO io

65+ :: MonadUnliftIO io

7466 => ByteString

7567 -- ^ The passed string can be empty to use all default parameters, or it can

7668 -- contain one or more parameter settings separated by whitespace.

@@ -86,68 +78,45 @@ createConnectionPool

8678 -> Int

8779 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

8880 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

89− -> io (Pool (K Connection schema))

90−createConnectionPool conninfo stripes idle maxResrc = liftBase $

81+ -> io (Pool (K Connection schemas))

82+createConnectionPool conninfo stripes idle maxResrc =

9183 createPool (connectdb conninfo) finish stripes idle maxResrc

9284

93−-- | `Applicative` instance for `PoolPQ`.

94−instance Monad m => Applicative (PoolPQ schema m) where

95− pure x = PoolPQ $ \ _ -> pure x

96− PoolPQ f <*> PoolPQ x = PoolPQ $ \ pool -> do

97− f' <- f pool

98− x' <- x pool

99− return $ f' x'

100−

101−-- | `Monad` instance for `PoolPQ`.

102−instance Monad m => Monad (PoolPQ schema m) where

103− return = pure

104− PoolPQ x >>= f = PoolPQ $ \ pool -> do

105− x' <- x pool

106− runPoolPQ (f x') pool

107−

108−-- | `MonadTrans` instance for `PoolPQ`.

109−instance MonadTrans (PoolPQ schema) where

110− lift m = PoolPQ $ \ _pool -> m

111−

112−-- | `MonadBase` instance for `PoolPQ`.

113−instance MonadBase b m => MonadBase b (PoolPQ schema m) where

114− liftBase = lift . liftBase

115−

116−-- | `MonadPQ` instance for `PoolPQ`.

117−instance MonadBaseControl IO io => MonadPQ schema (PoolPQ schema io) where

118− manipulateParams manipulation params = PoolPQ $ \ pool -> do

119− withResource pool $ \ conn -> do

120− (K result :: K (K Result ys) schema) <- flip unPQ conn $

121− manipulateParams manipulation params

122− return result

123− traversePrepared manipulation params = PoolPQ $ \ pool ->

124− withResource pool $ \ conn -> do

125− (K result :: K (list (K Result ys)) schema) <- flip unPQ conn $

126− traversePrepared manipulation params

127− return result

128− traversePrepared_ manipulation params = PoolPQ $ \ pool -> do

129− withResource pool $ \ conn -> do

130− (_ :: K () schema) <- flip unPQ conn $

131− traversePrepared_ manipulation params

132− return ()

133− liftPQ m = PoolPQ $ \ pool ->

134− withResource pool $ \ conn -> do

135− (K result :: K result schema) <- flip unPQ conn $

136− liftPQ m

137− return result

138−

139−-- | A snapshot of the state of a `PoolPQ` computation.

140−type PoolPQRun schema =

141− forall m x. Monad m => PoolPQ schema m x -> m x

142−

143−-- | Helper function in defining `MonadBaseControl` instance for `PoolPQ`.

144−poolpqliftWith :: Functor m => (PoolPQRun schema -> m a) -> PoolPQ schema m a

145−poolpqliftWith f = PoolPQ $ \ pool ->

146− (f $ \ pq -> runPoolPQ pq pool)

147−

148−-- | `MonadBaseControl` instance for `PoolPQ`.

149−instance MonadBaseControl b m => MonadBaseControl b (PoolPQ schema m) where

150− type StM (PoolPQ schema m) x = StM m x

151− liftBaseWith f =

152− poolpqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

153− restoreM = PoolPQ . const . restoreM

85+{-|

86+Temporarily take a connection from a `Pool`, perform an action with it,

87+and return it to the pool afterwards.

88+

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

101+

102+{- |

103+Destroy all connections in all stripes in the pool.

104+Note that this will ignore any exceptions in the destroy function.

105+

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.

112+

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+598−916

@@ -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

@@ -17,8 +17,12 @@ Squeal queries.

1717 , GeneralizedNewtypeDeriving

1818 , LambdaCase

1919 , MultiParamTypeClasses

20+ , OverloadedLabels

2021 , OverloadedStrings

22+ , QuantifiedConstraints

23+ , ScopedTypeVariables

2124 , StandaloneDeriving

25+ , TypeApplications

2226 , TypeFamilies

2327 , TypeInType

2428 , TypeOperators

@@ -28,14 +32,16 @@ Squeal queries.

2832

2933module Squeal.PostgreSQL.Query

3034 ( -- * Queries

31− Query (UnsafeQuery, renderQuery)

35+ Query_

36+ , Query (..)

3237 -- ** Select

3338 , select

39+ , select_

3440 , selectDistinct

35− , selectStar

36− , selectDistinctStar

37− , selectDotStar

38− , selectDistinctDotStar

41+ , selectDistinct_

42+ , selectDistinctOn

43+ , selectDistinctOn_

44+ , Selection (..)

3945 -- ** Values

4046 , values

4147 , values_

@@ -47,33 +53,15 @@ module Squeal.PostgreSQL.Query

4753 , except

4854 , exceptAll

4955 -- ** With

50− , With (with)

56+ , With (..)

5157 , CommonTableExpression (..)

52− , renderCommonTableExpression

53− , renderCommonTableExpressions

54− -- ** Json

55− , jsonEach

56− , jsonbEach

57− , jsonEachAsText

58− , jsonbEachAsText

59− , jsonObjectKeys

60− , jsonbObjectKeys

61− , jsonPopulateRecord

62− , jsonbPopulateRecord

63− , jsonPopulateRecordSet

64− , jsonbPopulateRecordSet

65− , jsonToRecord

66− , jsonbToRecord

67− , jsonToRecordSet

68− , jsonbToRecordSet

58+ , withRecursive

6959 -- * Table Expressions

7060 , TableExpression (..)

71− , renderTableExpression

7261 , from

7362 , where_

7463 , groupBy

7564 , having

76− , orderBy

7765 , limit

7866 , offset

7967 -- * From Clauses

@@ -81,53 +69,21 @@ module Squeal.PostgreSQL.Query

8169 , table

8270 , subquery

8371 , view

72+ , common

8473 , crossJoin

8574 , innerJoin

8675 , leftOuterJoin

8776 , rightOuterJoin

8877 , fullOuterJoin

8978 -- * Grouping

90− , By (By1, By2)

91− , renderBy

92− , GroupByClause (NoGroups, Group)

93− , renderGroupByClause

94− , HavingClause (NoHaving, Having)

95− , renderHavingClause

96− -- * Sorting

97− , SortExpression (..)

98− , renderSortExpression

99− -- * Subquery Expressions

100− , in_

101− , rowIn

102− , eqAll

103− , rowEqAll

104− , eqAny

105− , rowEqAny

106− , neqAll

107− , rowNeqAll

108− , neqAny

109− , rowNeqAny

110− , allLt

111− , rowLtAll

112− , ltAny

113− , rowLtAny

114− , lteAll

115− , rowLteAll

116− , lteAny

117− , rowLteAny

118− , gtAll

119− , rowGtAll

120− , gtAny

121− , rowGtAny

122− , gteAll

123− , rowGteAll

124− , gteAny

125− , rowGteAny

79+ , By (..)

80+ , GroupByClause (..)

81+ , HavingClause (..)

12682 ) where

12783

12884import Control.DeepSeq

12985import Data.ByteString (ByteString)

130−import Data.Monoid hiding (All)

86+import Data.Kind (Type)

13187import Data.String

13288import Data.Word

13389import Generics.SOP hiding (from)

@@ -135,23 +91,76 @@ import GHC.TypeLits

13591

13692import qualified GHC.Generics as GHC

13793

94+import Squeal.PostgreSQL.Alias

13895import 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

139101import Squeal.PostgreSQL.Render

140102import Squeal.PostgreSQL.Schema

141103

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+

142111{- |

143−The process of retrieving or the command to retrieve data from a database

144−is called a `Query`. Let's see some examples of 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+:}

145155

146156simple query:

147157

158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

148160>>> :{

149161let

150− query :: Query

151− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

152− '[]

153− '["col" ::: 'Null 'PGint4]

154− query = selectStar (from (table #tab))

162+ query :: Query_ (Public Schema) () (Row Int32 Int32)

163+ query = select Star (from (table #tab))

155164in printSQL query

156165:}

157166SELECT * FROM "tab" AS "tab"

@@ -160,34 +169,22 @@ restricted query:

160169

161170>>> :{

162171let

163− query :: Query

164− '[ "tab" ::: 'Table ('[] :=>

165− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

166− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

167− '[]

168− '[ "sum" ::: 'NotNull 'PGint4

169− , "col1" ::: 'NotNull 'PGint4 ]

172+ query :: Query_ (Public Schema) () (Row Int32 Int32)

170173 query =

171− select

172− ((#col1 + #col2) `as` #sum :* #col1)

174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)

173175 ( from (table #tab)

174176 & where_ (#col1 .> #col2)

175177 & where_ (#col2 .> 0) )

176178in printSQL query

177179:}

178−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))

179181

180182subquery:

181183

182184>>> :{

183185let

184− query :: Query

185− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

186− '[]

187− '["col" ::: 'Null 'PGint4]

188− query =

189− selectStar

190− (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)))

191188in printSQL query

192189:}

193190SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"

@@ -196,12 +193,8 @@ limits and offsets:

196193

197194>>> :{

198195let

199− query :: Query

200− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

201− '[]

202− '["col" ::: 'Null 'PGint4]

203− query = selectStar

204− (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)

205198in printSQL query

206199:}

207200SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4

@@ -210,85 +203,80 @@ parameterized query:

210203

211204>>> :{

212205let

213− query :: Query

214− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8])]

215− '[ 'NotNull 'PGfloat8]

216− '["col" ::: 'NotNull 'PGfloat8]

217− query = selectStar

218− (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))

219208in printSQL query

220209:}

221−SELECT * FROM "tab" AS "tab" WHERE ("col" > ($1 :: float8))

210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))

222211

223212aggregation query:

224213

225214>>> :{

226215let

227− query :: Query

228− '[ "tab" ::: 'Table ('[] :=>

229− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

230− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

231− '[]

232− '[ "sum" ::: 'NotNull 'PGint4

233− , "col1" ::: 'NotNull 'PGint4 ]

216+ query :: Query_ (Public Schema) () (Row Int64 Int32)

234217 query =

235− select (sum_ #col2 `as` #sum :* #col1)

218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)

236219 ( from (table (#tab `as` #table1))

237220 & groupBy #col1

238− & having (#col1 + sum_ #col2 .> 1) )

221+ & having (sum_ (Distinct #col2) .> 1) )

239222in printSQL query

240223:}

241−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)

242225

243226sorted query:

244227

245228>>> :{

246229let

247− query :: Query

248− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

249− '[]

250− '["col" ::: 'Null 'PGint4]

251− query = selectStar

252− (from (table #tab) & orderBy [#col & AscNullsFirst])

230+ query :: Query_ (Public Schema) () (Row Int32 Int32)

231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])

253232in printSQL query

254233:}

255−SELECT * FROM "tab" AS "tab" ORDER BY "col" ASC NULLS FIRST

234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC

256235

257236joins:

258237

259−>>> :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+

260273>>> :{

261274let

262− query :: Query

263− '[ "orders" ::: 'Table (

264− '["pk_orders" ::: PrimaryKey '["id"]

265− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]

266− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>

267− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

268− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4

269− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4

270− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4

271− ])

272− , "customers" ::: 'Table (

273− '["pk_customers" ::: PrimaryKey '["id"]] :=>

274− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

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

276− ])

277− , "shippers" ::: 'Table (

278− '["pk_shippers" ::: PrimaryKey '["id"]] :=>

279− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

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

281− ])

282− ]

283− '[]

284− '[ "order_price" ::: 'NotNull 'PGfloat4

285− , "customer_name" ::: 'NotNull 'PGtext

286− , "shipper_name" ::: 'NotNull 'PGtext

287− ]

288− query = select

289− ( #o ! #price `as` #order_price :*

290− #c ! #name `as` #customer_name :*

291− #s ! #name `as` #shipper_name )

275+ query :: Query_ (Public OrdersSchema) () Order

276+ query = select_

277+ ( #o ! #price `as` #price :*

278+ #c ! #name `as` #customerName :*

279+ #s ! #name `as` #shipperName )

292280 ( from (table (#orders `as` #o)

293281 & innerJoin (table (#customers `as` #c))

294282 (#o ! #customer_id .== #c ! #id)

@@ -296,17 +284,15 @@ let

296284 (#o ! #shipper_id .== #s ! #id)) )

297285in printSQL query

298286:}

299−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")

300288

301289self-join:

302290

303291>>> :{

304292let

305− query :: Query

306− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

307− '[]

308− '["col" ::: 'Null 'PGint4]

309− query = selectDotStar #t1

293+ query :: Query_ (Public Schema) () (Row Int32 Int32)

294+ query = select

295+ (#t1 & DotStar)

310296 (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))

311297in printSQL query

312298:}

@@ -316,24 +302,20 @@ value queries:

316302

317303>>> :{

318304let

319− query :: Query '[] '[] '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

320− query = values (1 `as` #foo :* true `as` #bar) [2 `as` #foo :* false `as` #bar]

305+ query :: Query_ schemas () (Row String Bool)

306+ query = values

307+ ("true" `as` #col1 :* true `as` #col2)

308+ ["false" `as` #col1 :* false `as` #col2]

321309in printSQL query

322310:}

323−SELECT * FROM (VALUES (1, TRUE), (2, FALSE)) AS t ("foo", "bar")

311+SELECT * FROM (VALUES (E'true', TRUE), (E'false', FALSE)) AS t ("col1", "col2")

324312

325313set operations:

326314

327315>>> :{

328316let

329− query :: Query

330− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

331− '[]

332− '["col" ::: 'Null 'PGint4]

333− query =

334− selectStar (from (table #tab))

335− `unionAll`

336− 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))

337319in printSQL query

338320:}

339321(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")

@@ -342,173 +324,305 @@ with queries:

342324

343325>>> :{

344326let

345− query :: Query

346− '[ "t1" ::: 'View

347− '[ "c1" ::: 'NotNull 'PGtext

348− , "c2" ::: 'NotNull 'PGtext] ]

349− '[]

350− '[ "c1" ::: 'NotNull 'PGtext

351− , "c2" ::: 'NotNull 'PGtext ]

327+ query :: Query_ (Public Schema) () (Row Int32 Int32)

352328 query = with (

353− selectStar (from (view #t1)) `as` #t2 :>>

354− selectStar (from (view #t2)) `as` #t3

355− ) (selectStar (from (view #t3)))

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)))))

356358in printSQL query

357359:}

358−WITH "t2" AS (SELECT * FROM "t1" AS "t1"), "t3" AS (SELECT * FROM "t2" AS "t2") SELECT * FROM "t3" AS "t3"

360+SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))

361+

359362-}

360−newtype Query

361− (schema :: SchemaType)

362− (params :: [NullityType])

363− (columns :: RowType)

364− = UnsafeQuery { renderQuery :: ByteString }

365− deriving (GHC.Generic,Show,Eq,Ord,NFData)

366−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)

367369

368370-- | The results of two queries can be combined using the set operation

369371-- `union`. Duplicate rows are eliminated.

370372union

371− :: Query schema params columns

372− -> Query schema params columns

373− -> 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

374376q1 `union` q2 = UnsafeQuery $

375− parenthesized (renderQuery q1)

377+ parenthesized (renderSQL q1)

376378 <+> "UNION"

377− <+> parenthesized (renderQuery q2)

379+ <+> parenthesized (renderSQL q2)

378380

379381-- | The results of two queries can be combined using the set operation

380382-- `unionAll`, the disjoint union. Duplicate rows are retained.

381383unionAll

382− :: Query schema params columns

383− -> Query schema params columns

384− -> 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

385387q1 `unionAll` q2 = UnsafeQuery $

386− parenthesized (renderQuery q1)

388+ parenthesized (renderSQL q1)

387389 <+> "UNION" <+> "ALL"

388− <+> parenthesized (renderQuery q2)

390+ <+> parenthesized (renderSQL q2)

389391

390392-- | The results of two queries can be combined using the set operation

391393-- `intersect`, the intersection. Duplicate rows are eliminated.

392394intersect

393− :: Query schema params columns

394− -> Query schema params columns

395− -> 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

396398q1 `intersect` q2 = UnsafeQuery $

397− parenthesized (renderQuery q1)

399+ parenthesized (renderSQL q1)

398400 <+> "INTERSECT"

399− <+> parenthesized (renderQuery q2)

401+ <+> parenthesized (renderSQL q2)

400402

401403-- | The results of two queries can be combined using the set operation

402404-- `intersectAll`, the intersection. Duplicate rows are retained.

403405intersectAll

404− :: Query schema params columns

405− -> Query schema params columns

406− -> 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

407409q1 `intersectAll` q2 = UnsafeQuery $

408− parenthesized (renderQuery q1)

410+ parenthesized (renderSQL q1)

409411 <+> "INTERSECT" <+> "ALL"

410− <+> parenthesized (renderQuery q2)

412+ <+> parenthesized (renderSQL q2)

411413

412414-- | The results of two queries can be combined using the set operation

413415-- `except`, the set difference. Duplicate rows are eliminated.

414416except

415− :: Query schema params columns

416− -> Query schema params columns

417− -> 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

418420q1 `except` q2 = UnsafeQuery $

419− parenthesized (renderQuery q1)

421+ parenthesized (renderSQL q1)

420422 <+> "EXCEPT"

421− <+> parenthesized (renderQuery q2)

423+ <+> parenthesized (renderSQL q2)

422424

423425-- | The results of two queries can be combined using the set operation

424426-- `exceptAll`, the set difference. Duplicate rows are retained.

425427exceptAll

426− :: Query schema params columns

427− -> Query schema params columns

428− -> 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

429431q1 `exceptAll` q2 = UnsafeQuery $

430− parenthesized (renderQuery q1)

432+ parenthesized (renderSQL q1)

431433 <+> "EXCEPT" <+> "ALL"

432− <+> parenthesized (renderQuery q2)

434+ <+> parenthesized (renderSQL q2)

433435

434436{-----------------------------------------

435437SELECT queries

436438-----------------------------------------}

437439

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+

438525-- | the `TableExpression` in the `select` command constructs an intermediate

439526-- virtual table by possibly combining tables, views, eliminating rows,

440527-- grouping, etc. This table is finally passed on to processing by

441−-- the select list. The select list determines which columns of

528+-- the select list. The `Selection` determines which columns of

442529-- the intermediate table are actually output.

443530select

444− :: SListI columns

445− => NP (Aliased (Expression schema from grouping params)) (column ': columns)

446− -- ^ select list

447− -> TableExpression schema params from 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

448535 -- ^ intermediate virtual table

449− -> Query schema params (column ': columns)

450−select list rels = UnsafeQuery $

536+ -> Query outer commons schemas params row

537+select selection tabexpr = UnsafeQuery $

451538 "SELECT"

452− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

453− <+> 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

454552

455553-- | After the select list has been processed, the result table can

456554-- be subject to the elimination of duplicate rows using `selectDistinct`.

457555selectDistinct

458− :: SListI columns

459− => NP (Aliased (Expression schema from 'Ungrouped params)) (column ': columns)

460− -- ^ select list

461− -> TableExpression schema params from '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

462560 -- ^ intermediate virtual table

463− -> Query schema params (column ': columns)

464−selectDistinct list rels = UnsafeQuery $

561+ -> Query outer commons schemas params columns

562+selectDistinct selection tabexpr = UnsafeQuery $

465563 "SELECT DISTINCT"

466− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

467− <+> renderTableExpression rels

468−

469−-- | The simplest kind of query is `selectStar` which emits all columns

470−-- that the table expression produces.

471−selectStar

472− :: HasUnique table from columns

473− => TableExpression schema params from 'Ungrouped

474− -- ^ intermediate virtual table

475− -> Query schema params columns

476−selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels

477−

478−-- | A `selectDistinctStar` emits all columns that the table expression

479−-- produces and eliminates duplicate rows.

480−selectDistinctStar

481− :: HasUnique table from columns

482− => TableExpression schema params from '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

483574 -- ^ intermediate virtual table

484− -> Query schema params columns

485−selectDistinctStar rels = UnsafeQuery $

486− "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels

487−

488−-- | When working with multiple tables, it can also be useful to ask

489−-- for all the columns of a particular table, using `selectDotStar`.

490−selectDotStar

491− :: Has table from columns

492− => Alias table

493− -- ^ particular virtual subtable

494− -> TableExpression schema params from '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

495598 -- ^ intermediate virtual table

496− -> Query schema params columns

497−selectDotStar rel tab = UnsafeQuery $

498− "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression tab

499−

500−-- | A `selectDistinctDotStar` asks for all the columns of a particular table,

501−-- and eliminates duplicate rows.

502−selectDistinctDotStar

503− :: Has table from columns

504− => Alias table

505− -- ^ particular virtual table

506− -> TableExpression schema params from '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

507623 -- ^ intermediate virtual table

508− -> Query schema params columns

509−selectDistinctDotStar rel tab = UnsafeQuery $

510− "SELECT DISTINCT" <+> renderAlias rel <> ".*"

511− <+> renderTableExpression tab

624+ -> Query outer commons schemas params columns

625+selectDistinctOn_ distincts = selectDistinctOn distincts . List

512626

513627-- | `values` computes a row value or set of row values

514628-- specified by value expressions. It is most commonly used

@@ -516,16 +630,16 @@ selectDistinctDotStar rel tab = UnsafeQuery $

516630-- but it can be used on its own.

517631--

518632-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]

519−-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query '[] '[] Row

633+-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query outer commons schemas '[] Row

520634-- >>> printSQL query

521635-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")

522636values

523637 :: SListI cols

524− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

525− -> [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]

526640 -- ^ When more than one row is specified, all the rows must

527641 -- must have the same number of elements

528− -> Query schema params cols

642+ -> Query outer commons schemas params cols

529643values rw rws = UnsafeQuery $ "SELECT * FROM"

530644 <+> parenthesized (

531645 "VALUES"

@@ -536,17 +650,17 @@ values rw rws = UnsafeQuery $ "SELECT * FROM"

536650 <+> parenthesized (renderCommaSeparated renderAliasPart rw)

537651 where

538652 renderAliasPart, renderValuePart

539− :: Aliased (Expression schema '[] 'Ungrouped params) ty -> ByteString

540− renderAliasPart (_ `As` name) = renderAlias name

541− 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

542656

543657-- | `values_` computes a row value or set of row values

544658-- specified by value expressions.

545659values_

546660 :: SListI cols

547− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

661+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

548662 -- ^ one row of values

549− -> Query schema params cols

663+ -> Query outer commons schemas params cols

550664values_ rw = values rw []

551665

552666{-----------------------------------------

@@ -560,15 +674,17 @@ Table Expressions

560674-- to a table on disk, a so-called base table, but more complex expressions

561675-- can be used to modify or combine base tables in various ways.

562676data TableExpression

563− (schema :: SchemaType)

677+ (outer :: FromType)

678+ (commons :: FromType)

679+ (grp :: Grouping)

680+ (schemas :: SchemasType)

564681 (params :: [NullityType])

565682 (from :: FromType)

566− (grouping :: Grouping)

567683 = TableExpression

568− { fromClause :: FromClause schema params from

684+ { fromClause :: FromClause outer commons schemas params from

569685 -- ^ A table reference that can be a table name, or a derived table such

570686 -- as a subquery, a @JOIN@ construct, or complex combinations of these.

571− , whereClause :: [Condition schema from 'Ungrouped params]

687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]

572688 -- ^ optional search coditions, combined with `.&&`. After the processing

573689 -- of the `fromClause` is done, each row of the derived virtual table

574690 -- is checked against the search condition. If the result of the

@@ -577,20 +693,20 @@ data TableExpression

577693 -- at least one column of the table generated in the `fromClause`;

578694 -- this is not required, but otherwise the WHERE clause will

579695 -- be fairly useless.

580− , groupByClause :: GroupByClause from grouping

696+ , groupByClause :: GroupByClause grp from

581697 -- ^ The `groupByClause` is used to group together those rows in a table

582698 -- that have the same values in all the columns listed. The order in which

583699 -- the columns are listed does not matter. The effect is to combine each

584700 -- set of rows having common values into one group row that represents all

585701 -- rows in the group. This is done to eliminate redundancy in the output

586702 -- and/or compute aggregates that apply to these groups.

587− , havingClause :: HavingClause schema from grouping params

703+ , havingClause :: HavingClause outer commons grp schemas params from

588704 -- ^ If a table has been grouped using `groupBy`, but only certain groups

589705 -- are of interest, the `havingClause` can be used, much like a

590706 -- `whereClause`, to eliminate groups from the result. Expressions in the

591707 -- `havingClause` can refer both to grouped expressions and to ungrouped

592708 -- expressions (which necessarily involve an aggregate function).

593− , orderByClause :: [SortExpression schema from grouping params]

709+ , orderByClause :: [SortExpression outer commons grp schemas params from]

594710 -- ^ The `orderByClause` is for optional sorting. When more than one

595711 -- `SortExpression` is specified, the later (right) values are used to sort

596712 -- rows that are equal according to the earlier (left) values.

@@ -600,72 +716,69 @@ data TableExpression

600716 -- will be returned (but possibly fewer, if the query itself yields

601717 -- fewer rows).

602718 , offsetClause :: [Word64]

603− -- ^ The `offsetClause` is combined with `+` to give an offset count

719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count

604720 -- if nonempty. The offset count says to skip that many rows before

605721 -- beginning to return rows. The rows are skipped before the limit count

606722 -- is applied.

607− }

723+ } deriving (GHC.Generic)

608724

609725-- | Render a `TableExpression`

610−renderTableExpression

611− :: TableExpression schema params from grouping

612− -> ByteString

613−renderTableExpression

614− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

615− [ "FROM ", renderFromClause frm'

616− , renderWheres whs'

617− , renderGroupByClause grps'

618− , renderHavingClause hvs'

619− , renderOrderByClause srts'

620− , renderLimits lims'

621− , renderOffsets offs'

622− ]

623− where

624− renderWheres = \case

625− [] -> ""

626− wh:[] -> " WHERE" <+> renderExpression wh

627− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

628− renderOrderByClause = \case

629− [] -> ""

630− srts -> " ORDER BY"

631− <+> commaSeparated (renderSortExpression <$> srts)

632− renderLimits = \case

633− [] -> ""

634− lims -> " LIMIT" <+> fromString (show (minimum lims))

635− renderOffsets = \case

636− [] -> ""

637− 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))

638751

639752-- | A `from` generates a `TableExpression` from a table reference that can be

640753-- a table name, or a derived table such as a subquery, a JOIN construct,

641754-- or complex combinations of these. A `from` may be transformed by `where_`,

642−-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

643756-- to match the left-to-right sequencing of their placement in SQL.

644757from

645− :: FromClause schema params from -- ^ table reference

646− -> TableExpression schema params from 'Ungrouped

647−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 [] [] []

648761

649762-- | A `where_` is an endomorphism of `TableExpression`s which adds a

650763-- search condition to the `whereClause`.

651764where_

652− :: Condition schema from 'Ungrouped params -- ^ filtering condition

653− -> TableExpression schema params from grouping

654− -> TableExpression schema params from 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

655768where_ wh rels = rels {whereClause = wh : whereClause rels}

656769

657770-- | A `groupBy` is a transformation of `TableExpression`s which switches

658−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform

771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform

659772-- a "grand total" aggregation query.

660773groupBy

661774 :: SListI bys

662775 => NP (By from) bys -- ^ grouped columns

663− -> TableExpression schema params from 'Ungrouped

664− -> TableExpression schema params from ('Grouped bys)

776+ -> TableExpression outer commons 'Ungrouped schemas params from

777+ -> TableExpression outer commons ('Grouped bys) schemas params from

665778groupBy bys rels = TableExpression

666779 { fromClause = fromClause rels

667780 , whereClause = whereClause rels

668− , groupByClause = Group bys

781+ , groupByClause = group bys

669782 , havingClause = Having []

670783 , orderByClause = []

671784 , limitClause = limitClause rels

@@ -675,177 +788,31 @@ groupBy bys rels = TableExpression

675788-- | A `having` is an endomorphism of `TableExpression`s which adds a

676789-- search condition to the `havingClause`.

677790having

678− :: Condition schema from ('Grouped bys) params -- ^ having condition

679− -> TableExpression schema params from ('Grouped bys)

680− -> TableExpression schema params from ('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

681794having hv rels = rels

682795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

683796

684−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an

685−-- ordering to the right of the `orderByClause`.

686−orderBy

687− :: [SortExpression schema from grouping params] -- ^ sort expressions

688− -> TableExpression schema params from grouping

689− -> TableExpression schema params from grouping

690−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

797+instance OrderBy TableExpression where

798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

691799

692800-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

693801-- `limitClause`.

694802limit

695803 :: Word64 -- ^ limit parameter

696− -> TableExpression schema params from grouping

697− -> TableExpression schema params from grouping

804+ -> TableExpression outer commons grp schemas params from

805+ -> TableExpression outer commons grp schemas params from

698806limit lim rels = rels {limitClause = lim : limitClause rels}

699807

700808-- | An `offset` is an endomorphism of `TableExpression`s which adds to the

701809-- `offsetClause`.

702810offset

703811 :: Word64 -- ^ offset parameter

704− -> TableExpression schema params from grouping

705− -> TableExpression schema params from grouping

812+ -> TableExpression outer commons grp schemas params from

813+ -> TableExpression outer commons grp schemas params from

706814offset off rels = rels {offsetClause = off : offsetClause rels}

707815

708−{-----------------------------------------

709−JSON stuff

710−-----------------------------------------}

711−

712−unsafeSetOfFunction

713− :: ByteString

714− -> Expression schema '[] 'Ungrouped params ty

715− -> Query schema params row

716−unsafeSetOfFunction fun expr = UnsafeQuery $

717− "SELECT * FROM " <> fun <> "(" <> renderExpression expr <> ")"

718−

719−-- | Expands the outermost JSON object into a set of key/value pairs.

720−jsonEach

721− :: Expression schema '[] 'Ungrouped params (nullity 'PGjson) -- ^ json object

722− -> Query schema params

723− '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGjson]

724−jsonEach = unsafeSetOfFunction "json_each"

725−

726−-- | Expands the outermost binary JSON object into a set of key/value pairs.

727−jsonbEach

728− :: Expression schema '[] 'Ungrouped params (nullity 'PGjsonb) -- ^ jsonb object

729− -> Query schema params

730− '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGjsonb]

731−jsonbEach = unsafeSetOfFunction "jsonb_each"

732−

733−-- | Expands the outermost JSON object into a set of key/value pairs.

734−jsonEachAsText

735− :: Expression schema '[] 'Ungrouped params (nullity 'PGjson) -- ^ json object

736− -> Query schema params

737− '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGtext]

738−jsonEachAsText = unsafeSetOfFunction "json_each_text"

739−

740−-- | Expands the outermost binary JSON object into a set of key/value pairs.

741−jsonbEachAsText

742− :: Expression schema '[] 'Ungrouped params (nullity 'PGjsonb) -- ^ jsonb object

743− -> Query schema params

744− '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGtext]

745−jsonbEachAsText = unsafeSetOfFunction "jsonb_each_text"

746−

747−-- | Returns set of keys in the outermost JSON object.

748−jsonObjectKeys

749− :: Expression schema '[] 'Ungrouped params (nullity 'PGjson) -- ^ json object

750− -> Query schema params '["json_object_keys" ::: 'NotNull 'PGtext]

751−jsonObjectKeys = unsafeSetOfFunction "json_object_keys"

752−

753−-- | Returns set of keys in the outermost JSON object.

754−jsonbObjectKeys

755− :: Expression schema '[] 'Ungrouped params (nullity 'PGjsonb) -- ^ jsonb object

756− -> Query schema params '["jsonb_object_keys" ::: 'NotNull 'PGtext]

757−jsonbObjectKeys = unsafeSetOfFunction "jsonb_object_keys"

758−

759−unsafePopulateFunction

760− :: ByteString

761− -> TypeExpression schema (nullity ('PGcomposite row))

762− -> Expression schema '[] 'Ungrouped params ty

763− -> Query schema params row

764−unsafePopulateFunction fun ty expr = UnsafeQuery $

765− "SELECT * FROM " <> fun <> "("

766− <> "null::" <> renderTypeExpression ty <> ", "

767− <> renderExpression expr <> ")"

768−

769−-- | Expands the JSON expression to a row whose columns match the record

770−-- type defined by the given table.

771−jsonPopulateRecord

772− :: TypeExpression schema (nullity ('PGcomposite row)) -- ^ row type

773− -> Expression schema '[] 'Ungrouped params (nullity 'PGjson) -- ^ json object

774− -> Query schema params row

775−jsonPopulateRecord = unsafePopulateFunction "json_populate_record"

776−

777−-- | Expands the binary JSON expression to a row whose columns match the record

778−-- type defined by the given table.

779−jsonbPopulateRecord

780− :: TypeExpression schema (nullity ('PGcomposite row)) -- ^ row type

781− -> Expression schema '[] 'Ungrouped params (nullity 'PGjsonb) -- ^ jsonb object

782− -> Query schema params row

783−jsonbPopulateRecord = unsafePopulateFunction "jsonb_populate_record"

784−

785−-- | Expands the outermost array of objects in the given JSON expression to a

786−-- set of rows whose columns match the record type defined by the given table.

787−jsonPopulateRecordSet

788− :: TypeExpression schema (nullity ('PGcomposite row)) -- ^ row type

789− -> Expression schema '[] 'Ungrouped params (nullity 'PGjson) -- ^ json array

790− -> Query schema params row

791−jsonPopulateRecordSet = unsafePopulateFunction "json_populate_record_set"

792−

793−-- | Expands the outermost array of objects in the given binary JSON expression

794−-- to a set of rows whose columns match the record type defined by the given

795−-- table.

796−jsonbPopulateRecordSet

797− :: TypeExpression schema (nullity ('PGcomposite row)) -- ^ row type

798− -> Expression schema '[] 'Ungrouped params (nullity 'PGjsonb) -- ^ jsonb array

799− -> Query schema params row

800−jsonbPopulateRecordSet = unsafePopulateFunction "jsonb_populate_record_set"

801−

802−unsafeRecordFunction

803− :: (SListI record, json `In` PGJsonType)

804− => ByteString

805− -> Expression schema '[] 'Ungrouped params (nullity json)

806− -> NP (Aliased (TypeExpression schema)) record

807− -> Query schema params record

808−unsafeRecordFunction fun expr types = UnsafeQuery $

809− "SELECT * FROM " <> fun <> "("

810− <> renderExpression expr <> ")"

811− <+> "AS" <+> "x" <> parenthesized (renderCommaSeparated renderTy types)

812− where

813− renderTy :: Aliased (TypeExpression schema) ty -> ByteString

814− renderTy (ty `As` alias) =

815− renderAlias alias <+> renderTypeExpression ty

816−

817−-- | Builds an arbitrary record from a JSON object.

818−jsonToRecord

819− :: SListI record

820− => Expression schema '[] 'Ungrouped params (nullity 'PGjson) -- ^ json object

821− -> NP (Aliased (TypeExpression schema)) record -- ^ record types

822− -> Query schema params record

823−jsonToRecord = unsafeRecordFunction "json_to_record"

824−

825−-- | Builds an arbitrary record from a binary JSON object.

826−jsonbToRecord

827− :: SListI record

828− => Expression schema '[] 'Ungrouped params (nullity 'PGjsonb) -- ^ jsonb object

829− -> NP (Aliased (TypeExpression schema)) record -- ^ record types

830− -> Query schema params record

831−jsonbToRecord = unsafeRecordFunction "jsonb_to_record"

832−

833−-- | Builds an arbitrary set of records from a JSON array of objects.

834−jsonToRecordSet

835− :: SListI record

836− => Expression schema '[] 'Ungrouped params (nullity 'PGjson) -- ^ json array

837− -> NP (Aliased (TypeExpression schema)) record -- ^ record types

838− -> Query schema params record

839−jsonToRecordSet = unsafeRecordFunction "json_to_record_set"

840−

841−-- | Builds an arbitrary set of records from a binary JSON array of objects.

842−jsonbToRecordSet

843− :: SListI record

844− => Expression schema '[] 'Ungrouped params (nullity 'PGjsonb) -- ^ jsonb array

845− -> NP (Aliased (TypeExpression schema)) record -- ^ record types

846− -> Query schema params record

847−jsonbToRecordSet = unsafeRecordFunction "jsonb_to_record_set"

848−

849816{-----------------------------------------

850817FROM clauses

851818-----------------------------------------}

@@ -854,61 +821,76 @@ FROM clauses

854821A `FromClause` can be a table name, or a derived table such

855822as a subquery, a @JOIN@ construct, or complex combinations of these.

856823-}

857−newtype FromClause schema params from

824+newtype FromClause outer commons schemas params from

858825 = UnsafeFromClause { renderFromClause :: ByteString }

859826 deriving (GHC.Generic,Show,Eq,Ord,NFData)

827+instance RenderSQL (FromClause outer commons schemas params from) where

828+ renderSQL = renderFromClause

860829

861−-- | A real `table` is a table from the schema.

830+-- | A real `table` is a table from the database.

862831table

863− :: Has tab schema ('Table table)

864− => Aliased Alias (alias ::: tab)

865− -> FromClause schema params '[alias ::: TableToRow 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]

866835table (tab `As` alias) = UnsafeFromClause $

867− renderAlias tab <+> "AS" <+> renderAlias alias

836+ renderSQL tab <+> "AS" <+> renderSQL alias

868837

869838-- | `subquery` derives a table from a `Query`.

870839subquery

871− :: Aliased (Query schema params) rel

872− -> FromClause schema params '[rel]

873−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)

874843

875844-- | `view` derives a table from a `View`.

876845view

877− :: Has view schema ('View row)

878− => Aliased Alias (alias ::: view)

879− -> FromClause schema params '[alias ::: row]

846+ :: (Has sch schemas schema, Has vw schema ('View view))

847+ => Aliased (QualifiedAlias sch) (alias ::: vw)

848+ -> FromClause outer commons schemas params '[alias ::: view]

880849view (vw `As` alias) = UnsafeFromClause $

881− 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

882863

883−{- | @left & crossJoin right@. For every possible combination of rows from

884− @left@ and @right@ (i.e., a Cartesian product), the joined table will contain

885− a row consisting of all columns in @left@ followed by all columns in @right@.

886− If the tables have @n@ and @m@ rows respectively, the joined table will

887− 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.

888870-}

889871crossJoin

890− :: FromClause schema params right

872+ :: FromClause outer commons schemas params right

891873 -- ^ right

892− -> FromClause schema params left

874+ -> FromClause outer commons schemas params left

893875 -- ^ left

894− -> FromClause schema params (Join left right)

876+ -> FromClause outer commons schemas params (Join left right)

895877crossJoin right left = UnsafeFromClause $

896− renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right

878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right

897879

898880{- | @left & innerJoin right on@. The joined table is filtered by

899881the @on@ condition.

900882-}

901883innerJoin

902− :: FromClause schema params right

884+ :: FromClause outer commons schemas params right

903885 -- ^ right

904− -> Condition schema (Join left right) 'Ungrouped params

886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

905887 -- ^ @on@ condition

906− -> FromClause schema params left

888+ -> FromClause outer commons schemas params left

907889 -- ^ left

908− -> FromClause schema params (Join left right)

890+ -> FromClause outer commons schemas params (Join left right)

909891innerJoin right on left = UnsafeFromClause $

910− renderFromClause left <+> "INNER JOIN" <+> renderFromClause right

911− <+> "ON" <+> renderExpression on

892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right

893+ <+> "ON" <+> renderSQL on

912894

913895{- | @left & leftOuterJoin right on@. First, an inner join is performed.

914896 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -916,16 +898,16 @@ innerJoin right on left = UnsafeFromClause $

916898 Thus, the joined table always has at least one row for each row in @left@.

917899-}

918900leftOuterJoin

919− :: FromClause schema params right

901+ :: FromClause outer commons schemas params right

920902 -- ^ right

921− -> Condition schema (Join left right) 'Ungrouped params

903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

922904 -- ^ @on@ condition

923− -> FromClause schema params left

905+ -> FromClause outer commons schemas params left

924906 -- ^ left

925− -> FromClause schema params (Join left (NullifyFrom right))

907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))

926908leftOuterJoin right on left = UnsafeFromClause $

927− renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right

928− <+> "ON" <+> renderExpression on

909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right

910+ <+> "ON" <+> renderSQL on

929911

930912{- | @left & rightOuterJoin right on@. First, an inner join is performed.

931913 Then, for each row in @right@ that does not satisfy the @on@ condition with

@@ -934,16 +916,16 @@ leftOuterJoin right on left = UnsafeFromClause $

934916 have a row for each row in @right@.

935917-}

936918rightOuterJoin

937− :: FromClause schema params right

919+ :: FromClause outer commons schemas params right

938920 -- ^ right

939− -> Condition schema (Join left right) 'Ungrouped params

921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

940922 -- ^ @on@ condition

941− -> FromClause schema params left

923+ -> FromClause outer commons schemas params left

942924 -- ^ left

943− -> FromClause schema params (Join (NullifyFrom left) right)

925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)

944926rightOuterJoin right on left = UnsafeFromClause $

945− renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right

946− <+> "ON" <+> renderExpression on

927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right

928+ <+> "ON" <+> renderSQL on

947929

948930{- | @left & fullOuterJoin right on@. First, an inner join is performed.

949931 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -953,23 +935,23 @@ rightOuterJoin right on left = UnsafeFromClause $

953935 is added.

954936-}

955937fullOuterJoin

956− :: FromClause schema params right

938+ :: FromClause outer commons schemas params right

957939 -- ^ right

958− -> Condition schema (Join left right) 'Ungrouped params

940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

959941 -- ^ @on@ condition

960− -> FromClause schema params left

942+ -> FromClause outer commons schemas params left

961943 -- ^ left

962− -> FromClause schema params

944+ -> FromClause outer commons schemas params

963945 (Join (NullifyFrom left) (NullifyFrom right))

964946fullOuterJoin right on left = UnsafeFromClause $

965− renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right

966− <+> "ON" <+> renderExpression on

947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right

948+ <+> "ON" <+> renderSQL on

967949

968950{-----------------------------------------

969951Grouping

970952-----------------------------------------}

971953

972−-- | `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

973955-- used to group together those rows in a table that have the same values

974956-- in all the columns listed. @By \#col@ will reference an unambiguous

975957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

@@ -989,6 +971,10 @@ data By

989971deriving instance Show (By from by)

990972deriving instance Eq (By from by)

991973deriving 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

992978

993979instance (HasUnique rel rels cols, Has col cols ty, by ~ '(rel, col))

994980 => IsLabel col (By rels by) where fromLabel = By1 fromLabel

@@ -1000,417 +986,113 @@ instance (Has rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

1000986 => IsQualified rel col (NP (By rels) bys) where

1001987 rel ! col = By2 rel col :* Nil

1002988

1003−-- | Renders a `By`.

1004−renderBy :: By from by -> ByteString

1005−renderBy = \case

1006− By1 column -> renderAlias column

1007− By2 rel column -> renderAlias rel <> "." <> renderAlias column

1008−

1009989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

1010990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

1011991-- @NoGroups@ is distinguised from @Group Nil@ since no aggregation can be

1012992-- done on @NoGroups@ while all output `Expression`s must be aggregated

1013993-- in @Group Nil@. In general, all output `Expression`s in the

1014994-- complement of @bys@ must be aggregated in @Group bys@.

1015−data GroupByClause from grouping where

1016− NoGroups :: GroupByClause from 'Ungrouped

1017− Group

1018− :: SListI bys

1019− => NP (By from) bys

1020− -> GroupByClause from ('Grouped bys)

1021−

1022−-- | Renders a `GroupByClause`.

1023−renderGroupByClause :: GroupByClause from grouping -> ByteString

1024−renderGroupByClause = \case

1025− NoGroups -> ""

1026− Group Nil -> ""

1027− 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'

10281009

10291010-- | A `HavingClause` is used to eliminate groups that are not of interest.

10301011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

10311012-- `TableExpression` must use `Having` whose conditions are combined with

10321013-- `.&&`.

1033−data HavingClause schema from grouping params where

1034− NoHaving :: HavingClause schema from 'Ungrouped params

1014+data HavingClause outer commons grp schemas params from where

1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from

10351016 Having

1036− :: [Condition schema from ('Grouped bys) params]

1037− -> HavingClause schema from ('Grouped bys) params

1038−deriving instance Show (HavingClause schema from grouping params)

1039−deriving instance Eq (HavingClause schema from grouping params)

1040−deriving instance Ord (HavingClause schema from 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)

10411022

10421023-- | Render a `HavingClause`.

1043−renderHavingClause :: HavingClause schema from grouping params -> ByteString

1044−renderHavingClause = \case

1045− NoHaving -> ""

1046− Having [] -> ""

1047− Having conditions ->

1048− " HAVING" <+> commaSeparated (renderExpression <$> conditions)

1049−

1050−{-----------------------------------------

1051−Sorting

1052−-----------------------------------------}

1053−

1054−-- | `SortExpression`s are used by `sortBy` to optionally sort the results

1055−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result

1056−-- column to ascending or descending. Ascending order puts smaller values

1057−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,

1058−-- descending order is determined with the `.>` operator. `AscNullsFirst`,

1059−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

1060−-- determine whether nulls appear before or after non-null values in the sort

1061−-- ordering of a `Null` result column.

1062−data SortExpression schema from grouping params where

1063− Asc

1064− :: Expression schema from grouping params ('NotNull ty)

1065− -> SortExpression schema from grouping params

1066− Desc

1067− :: Expression schema from grouping params ('NotNull ty)

1068− -> SortExpression schema from grouping params

1069− AscNullsFirst

1070− :: Expression schema from grouping params ('Null ty)

1071− -> SortExpression schema from grouping params

1072− AscNullsLast

1073− :: Expression schema from grouping params ('Null ty)

1074− -> SortExpression schema from grouping params

1075− DescNullsFirst

1076− :: Expression schema from grouping params ('Null ty)

1077− -> SortExpression schema from grouping params

1078− DescNullsLast

1079− :: Expression schema from grouping params ('Null ty)

1080− -> SortExpression schema from grouping params

1081−deriving instance Show (SortExpression schema from grouping params)

1082−

1083−-- | Render a `SortExpression`.

1084−renderSortExpression :: SortExpression schema from grouping params -> ByteString

1085−renderSortExpression = \case

1086− Asc expression -> renderExpression expression <+> "ASC"

1087− Desc expression -> renderExpression expression <+> "DESC"

1088− AscNullsFirst expression -> renderExpression expression

1089− <+> "ASC NULLS FIRST"

1090− DescNullsFirst expression -> renderExpression expression

1091− <+> "DESC NULLS FIRST"

1092− AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"

1093− DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"

1094−

1095−unsafeSubqueryExpression

1096− :: ByteString

1097− -> Expression schema from grp params ty

1098− -> Query schema params '[alias ::: ty]

1099− -> Expression schema from grp params (nullity 'PGbool)

1100−unsafeSubqueryExpression op x q = UnsafeExpression $

1101− renderExpression x <+> op <+> parenthesized (renderQuery q)

1102−

1103−unsafeRowSubqueryExpression

1104− :: SListI row

1105− => ByteString

1106− -> NP (Aliased (Expression schema from grp params)) row

1107− -> Query schema params row

1108− -> Expression schema from grp params (nullity 'PGbool)

1109−unsafeRowSubqueryExpression op xs q = UnsafeExpression $

1110− renderExpression (row xs) <+> op <+> parenthesized (renderQuery q)

1111−

1112−-- | The right-hand side is a sub`Query`, which must return exactly one column.

1113−-- The left-hand expression is evaluated and compared to each row of the

1114−-- sub`Query` result. The result of `in_` is `true` if any equal subquery row is found.

1115−-- The result is `false` if no equal row is found

1116−-- (including the case where the subquery returns no rows).

1117−--

1118−-- >>> printSQL $ true `in_` values_ (true `as` #foo)

1119−-- TRUE IN (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1120−in_

1121− :: Expression schema from grp params ty -- ^ expression

1122− -> Query schema params '[alias ::: ty] -- ^ subquery

1123− -> Expression schema from grp params (nullity 'PGbool)

1124−in_ = unsafeSubqueryExpression "IN"

1125−

1126−{- | The left-hand side of this form of `rowIn` is a row constructor.

1127−The right-hand side is a sub`Query`,

1128−which must return exactly as many columns as

1129−there are expressions in the left-hand row.

1130−The left-hand expressions are evaluated and compared row-wise to each row

1131−of the subquery result. The result of `rowIn`

1132−is `true` if any equal subquery row is found.

1133−The result is `false` if no equal row is found

1134−(including the case where the subquery returns no rows).

1135−

1136−>>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1137−>>> printSQL $ myRow `rowIn` values_ myRow

1138−ROW(1, FALSE) IN (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1139−-}

1140−rowIn

1141− :: SListI row

1142− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1143− -> Query schema params row -- ^ subquery

1144− -> Expression schema from grp params (nullity 'PGbool)

1145−rowIn = unsafeRowSubqueryExpression "IN"

1146−

1147−-- | >>> printSQL $ true `eqAll` values_ (true `as` #foo)

1148−-- TRUE = ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1149−eqAll

1150− :: Expression schema from grp params ty -- ^ expression

1151− -> Query schema params '[alias ::: ty] -- ^ subquery

1152− -> Expression schema from grp params (nullity 'PGbool)

1153−eqAll = unsafeSubqueryExpression "= ALL"

1154−

1155−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1156−-- >>> printSQL $ myRow `rowEqAll` values_ myRow

1157−-- ROW(1, FALSE) = ALL (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1158−rowEqAll

1159− :: SListI row

1160− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1161− -> Query schema params row -- ^ subquery

1162− -> Expression schema from grp params (nullity 'PGbool)

1163−rowEqAll = unsafeRowSubqueryExpression "= ALL"

1164−

1165−-- | >>> printSQL $ true `eqAny` values_ (true `as` #foo)

1166−-- TRUE = ANY (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1167−eqAny

1168− :: Expression schema from grp params ty -- ^ expression

1169− -> Query schema params '[alias ::: ty] -- ^ subquery

1170− -> Expression schema from grp params (nullity 'PGbool)

1171−eqAny = unsafeSubqueryExpression "= ANY"

1172−

1173−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1174−-- >>> printSQL $ myRow `rowEqAny` values_ myRow

1175−-- ROW(1, FALSE) = ANY (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1176−rowEqAny

1177− :: SListI row

1178− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1179− -> Query schema params row -- ^ subquery

1180− -> Expression schema from grp params (nullity 'PGbool)

1181−rowEqAny = unsafeRowSubqueryExpression "= ANY"

1182−

1183−-- | >>> printSQL $ true `neqAll` values_ (true `as` #foo)

1184−-- TRUE <> ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1185−neqAll

1186− :: Expression schema from grp params ty -- ^ expression

1187− -> Query schema params '[alias ::: ty] -- ^ subquery

1188− -> Expression schema from grp params (nullity 'PGbool)

1189−neqAll = unsafeSubqueryExpression "<> ALL"

1190−

1191−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1192−-- >>> printSQL $ myRow `rowNeqAll` values_ myRow

1193−-- ROW(1, FALSE) <> ALL (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1194−rowNeqAll

1195− :: SListI row

1196− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1197− -> Query schema params row -- ^ subquery

1198− -> Expression schema from grp params (nullity 'PGbool)

1199−rowNeqAll = unsafeRowSubqueryExpression "<> ALL"

1200−

1201−-- | >>> printSQL $ true `neqAny` values_ (true `as` #foo)

1202−-- TRUE <> ANY (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1203−neqAny

1204− :: Expression schema from grp params ty -- ^ expression

1205− -> Query schema params '[alias ::: ty] -- ^ subquery

1206− -> Expression schema from grp params (nullity 'PGbool)

1207−neqAny = unsafeSubqueryExpression "<> ANY"

1208−

1209−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1210−-- >>> printSQL $ myRow `rowNeqAny` values_ myRow

1211−-- ROW(1, FALSE) <> ANY (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1212−rowNeqAny

1213− :: SListI row

1214− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1215− -> Query schema params row -- ^ subquery

1216− -> Expression schema from grp params (nullity 'PGbool)

1217−rowNeqAny = unsafeRowSubqueryExpression "<> ANY"

1218−

1219−-- | >>> printSQL $ true `allLt` values_ (true `as` #foo)

1220−-- TRUE ALL < (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1221−allLt

1222− :: Expression schema from grp params ty -- ^ expression

1223− -> Query schema params '[alias ::: ty] -- ^ subquery

1224− -> Expression schema from grp params (nullity 'PGbool)

1225−allLt = unsafeSubqueryExpression "ALL <"

1226−

1227−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1228−-- >>> printSQL $ myRow `rowLtAll` values_ myRow

1229−-- ROW(1, FALSE) ALL < (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1230−rowLtAll

1231− :: SListI row

1232− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1233− -> Query schema params row -- ^ subquery

1234− -> Expression schema from grp params (nullity 'PGbool)

1235−rowLtAll = unsafeRowSubqueryExpression "ALL <"

1236−

1237−-- | >>> printSQL $ true `ltAny` values_ (true `as` #foo)

1238−-- TRUE ANY < (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1239−ltAny

1240− :: Expression schema from grp params ty -- ^ expression

1241− -> Query schema params '[alias ::: ty] -- ^ subquery

1242− -> Expression schema from grp params (nullity 'PGbool)

1243−ltAny = unsafeSubqueryExpression "ANY <"

1244−

1245−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1246−-- >>> printSQL $ myRow `rowLtAll` values_ myRow

1247−-- ROW(1, FALSE) ALL < (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1248−rowLtAny

1249− :: SListI row

1250− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1251− -> Query schema params row -- ^ subquery

1252− -> Expression schema from grp params (nullity 'PGbool)

1253−rowLtAny = unsafeRowSubqueryExpression "ANY <"

1254−

1255−-- | >>> printSQL $ true `lteAll` values_ (true `as` #foo)

1256−-- TRUE <= ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1257−lteAll

1258− :: Expression schema from grp params ty -- ^ expression

1259− -> Query schema params '[alias ::: ty] -- ^ subquery

1260− -> Expression schema from grp params (nullity 'PGbool)

1261−lteAll = unsafeSubqueryExpression "<= ALL"

1262−

1263−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1264−-- >>> printSQL $ myRow `rowLteAll` values_ myRow

1265−-- ROW(1, FALSE) <= ALL (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1266−rowLteAll

1267− :: SListI row

1268− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1269− -> Query schema params row -- ^ subquery

1270− -> Expression schema from grp params (nullity 'PGbool)

1271−rowLteAll = unsafeRowSubqueryExpression "<= ALL"

1272−

1273−-- | >>> printSQL $ true `lteAny` values_ (true `as` #foo)

1274−-- TRUE <= ANY (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1275−lteAny

1276− :: Expression schema from grp params ty -- ^ expression

1277− -> Query schema params '[alias ::: ty] -- ^ subquery

1278− -> Expression schema from grp params (nullity 'PGbool)

1279−lteAny = unsafeSubqueryExpression "<= ANY"

1280−

1281−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1282−-- >>> printSQL $ myRow `rowLteAny` values_ myRow

1283−-- ROW(1, FALSE) <= ANY (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1284−rowLteAny

1285− :: SListI row

1286− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1287− -> Query schema params row -- ^ subquery

1288− -> Expression schema from grp params (nullity 'PGbool)

1289−rowLteAny = unsafeRowSubqueryExpression "<= ANY"

1290−

1291−-- | >>> printSQL $ true `gtAll` values_ (true `as` #foo)

1292−-- TRUE > ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1293−gtAll

1294− :: Expression schema from grp params ty -- ^ expression

1295− -> Query schema params '[alias ::: ty] -- ^ subquery

1296− -> Expression schema from grp params (nullity 'PGbool)

1297−gtAll = unsafeSubqueryExpression "> ALL"

1298−

1299−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1300−-- >>> printSQL $ myRow `rowGtAll` values_ myRow

1301−-- ROW(1, FALSE) > ALL (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1302−rowGtAll

1303− :: SListI row

1304− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1305− -> Query schema params row -- ^ subquery

1306− -> Expression schema from grp params (nullity 'PGbool)

1307−rowGtAll = unsafeRowSubqueryExpression "> ALL"

1308−

1309−-- | >>> printSQL $ true `gtAny` values_ (true `as` #foo)

1310−-- TRUE > ANY (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1311−gtAny

1312− :: Expression schema from grp params ty -- ^ expression

1313− -> Query schema params '[alias ::: ty] -- ^ subquery

1314− -> Expression schema from grp params (nullity 'PGbool)

1315−gtAny = unsafeSubqueryExpression "> ANY"

1316−

1317−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1318−-- >>> printSQL $ myRow `rowGtAny` values_ myRow

1319−-- ROW(1, FALSE) > ANY (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1320−rowGtAny

1321− :: SListI row

1322− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1323− -> Query schema params row -- ^ subquery

1324− -> Expression schema from grp params (nullity 'PGbool)

1325−rowGtAny = unsafeRowSubqueryExpression "> ANY"

1326−

1327−-- | >>> printSQL $ true `gteAll` values_ (true `as` #foo)

1328−-- TRUE >= ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1329−gteAll

1330− :: Expression schema from grp params ty -- ^ expression

1331− -> Query schema params '[alias ::: ty] -- ^ subquery

1332− -> Expression schema from grp params (nullity 'PGbool)

1333−gteAll = unsafeSubqueryExpression ">= ALL"

1334−

1335−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1336−-- >>> printSQL $ myRow `rowGteAll` values_ myRow

1337−-- ROW(1, FALSE) >= ALL (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1338−rowGteAll

1339− :: SListI row

1340− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1341− -> Query schema params row -- ^ subquery

1342− -> Expression schema from grp params (nullity 'PGbool)

1343−rowGteAll = unsafeRowSubqueryExpression ">= ALL"

1344−

1345−-- | >>> printSQL $ true `gteAny` values_ (true `as` #foo)

1346−-- TRUE >= ANY (SELECT * FROM (VALUES (TRUE)) AS t ("foo"))

1347−gteAny

1348− :: Expression schema from grp params ty -- ^ expression

1349− -> Query schema params '[alias ::: ty] -- ^ subquery

1350− -> Expression schema from grp params (nullity 'PGbool)

1351−gteAny = unsafeSubqueryExpression ">= ANY"

1352−

1353−-- | >>> let myRow = 1 `as` #foo :* false `as` #bar :: NP (Aliased (Expression '[] '[] 'Ungrouped '[])) '["foo" ::: 'NotNull 'PGint2, "bar" ::: 'NotNull 'PGbool]

1354−-- >>> printSQL $ myRow `rowGteAny` values_ myRow

1355−-- ROW(1, FALSE) >= ANY (SELECT * FROM (VALUES (1, FALSE)) AS t ("foo", "bar"))

1356−rowGteAny

1357− :: SListI row

1358− => NP (Aliased (Expression schema from grp params)) row -- ^ row constructor

1359− -> Query schema params row -- ^ subquery

1360− -> Expression schema from grp params (nullity 'PGbool)

1361−rowGteAny = unsafeRowSubqueryExpression ">= ANY"

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)

13621030

13631031-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.

13641032data CommonTableExpression statement

1033+ (schemas :: SchemasType)

13651034 (params :: [NullityType])

1366− (schema0 :: SchemaType)

1367− (schema1 :: SchemaType) where

1035+ (commons0 :: FromType)

1036+ (commons1 :: FromType) where

13681037 CommonTableExpression

1369− :: Aliased (statement schema params) (alias ::: cte)

1370− -> CommonTableExpression

1371− statement params schema (alias ::: 'View cte ': schema)

1372−instance (KnownSymbol alias, schema1 ~ (alias ::: 'View cte ': schema))

1373− => Aliasable alias

1374− (statement schema params cte)

1375− (CommonTableExpression statement params schema schema1) where

1376− statement `as` alias = CommonTableExpression (statement `as` alias)

1377−instance (KnownSymbol alias, schema1 ~ (alias ::: 'View cte ': schema))

1378− => Aliasable alias (statement schema params cte)

1379− (AlignedList (CommonTableExpression statement params) schema schema1) where

1380− statement `as` alias = single (statement `as` alias)

1381−

1382−-- | render a `CommonTableExpression`.

1383−renderCommonTableExpression

1384− :: (forall sch ps row. statement ps sch row -> ByteString) -- ^ render statement

1385− -> CommonTableExpression statement params schema0 schema1 -> ByteString

1386−renderCommonTableExpression renderStatement

1387− (CommonTableExpression (statement `As` alias)) =

1388− renderAlias alias <+> "AS" <+> parenthesized (renderStatement statement)

1389−

1390−-- | render a non-empty `AlignedList` of `CommonTableExpression`s.

1391−renderCommonTableExpressions

1392− :: (forall sch ps row. statement ps sch row -> ByteString) -- ^ render statement

1393− -> CommonTableExpression statement params schema0 schema1

1394− -> AlignedList (CommonTableExpression statement params) schema1 schema2

1395− -> ByteString

1396−renderCommonTableExpressions renderStatement cte ctes =

1397− renderCommonTableExpression renderStatement cte <> case ctes of

1398− Done -> ""

1399− cte' :>> ctes' -> "," <+>

1400− renderCommonTableExpressions renderStatement cte' ctes'

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)

14011059

14021060-- | `with` provides a way to write auxiliary statements for use in a larger query.

14031061-- These statements, referred to as `CommonTableExpression`s, can be thought of as

14041062-- defining temporary tables that exist just for one query.

14051063class With statement where

14061064 with

1407− :: AlignedList (CommonTableExpression statement params) schema0 schema1

1065+ :: Path (CommonTableExpression statement schemas params) commons0 commons1

14081066 -- ^ common table expressions

1409− -> statement schema1 params row

1067+ -> statement commons1 schemas params row

14101068 -- ^ larger query

1411− -> statement schema0 params row

1412−instance With Query where

1069+ -> statement commons0 schemas params row

1070+instance With (Query outer) where

14131071 with Done query = query

1414− with (cte :>> ctes) query = UnsafeQuery $

1415− "WITH" <+> renderCommonTableExpressions renderQuery cte ctes

1416− <+> renderQuery query

1072+ with ctes query = UnsafeQuery $

1073+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL query

1074+

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+47−14

@@ -10,7 +10,9 @@ Rendering helper functions.

1010

1111{-# LANGUAGE

1212 AllowAmbiguousTypes

13+ , ConstraintKinds

1314 , FlexibleContexts

15+ , LambdaCase

1416 , MagicHash

1517 , OverloadedStrings

1618 , PolyKinds

@@ -21,30 +23,34 @@ Rendering helper functions.

2123

2224module Squeal.PostgreSQL.Render

2325 ( -- * Render

24− parenthesized

26+ RenderSQL (..)

27+ , printSQL

28+ , escape

29+ , parenthesized

30+ , bracketed

2531 , (<+>)

2632 , commaSeparated

2733 , doubleQuoted

2834 , singleQuotedText

2935 , singleQuotedUtf8

3036 , renderCommaSeparated

37+ , renderCommaSeparatedConstraint

3138 , renderCommaSeparatedMaybe

3239 , renderNat

3340 , renderSymbol

34− , RenderSQL (..)

35− , printSQL

3641 ) where

3742

38−import Control.Monad.Base

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

3944import Data.ByteString (ByteString)

40−import Data.Maybe

45+import Data.Maybe (catMaybes)

4146import Data.Monoid ((<>))

4247import Data.Text (Text)

4348import Generics.SOP

4449import GHC.Exts

45−import GHC.TypeLits

46−import qualified Data.Text as T

47−import qualified Data.Text.Encoding as T

50+import GHC.TypeLits hiding (Text)

51+

52+import qualified Data.Text as Text

53+import qualified Data.Text.Encoding as Text

4854import qualified Data.ByteString as ByteString

4955import qualified Data.ByteString.Char8 as Char8

5056

@@ -52,6 +58,10 @@ import qualified Data.ByteString.Char8 as Char8

5258parenthesized :: ByteString -> ByteString

5359parenthesized str = "(" <> str <> ")"

5460

61+-- | Square bracket a `ByteString`

62+bracketed :: ByteString -> ByteString

63+bracketed str = "[" <> str <> "]"

64+

5565-- | Concatenate two `ByteString`s with a space between.

5666(<+>) :: ByteString -> ByteString -> ByteString

5767infixr 7 <+>

@@ -67,11 +77,12 @@ doubleQuoted str = "\"" <> str <> "\""

6777

6878-- | Add single quotes around a `Text` and escape single quotes within it.

6979singleQuotedText :: Text -> ByteString

70−singleQuotedText str = "'" <> T.encodeUtf8 (T.replace "'" "''" str) <> "'"

80+singleQuotedText str =

81+ "'" <> Text.encodeUtf8 (Text.replace "'" "''" str) <> "'"

7182

7283-- | Add single quotes around a `ByteString` and escape single quotes within it.

7384singleQuotedUtf8 :: ByteString -> ByteString

74−singleQuotedUtf8 = singleQuotedText . T.decodeUtf8

85+singleQuotedUtf8 = singleQuotedText . Text.decodeUtf8

7586

7687-- | Comma separate the renderings of a heterogeneous list.

7788renderCommaSeparated

@@ -83,6 +94,16 @@ renderCommaSeparated render

8394 . hcollapse

8495 . hmap (K . render)

8596

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+

86107-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

87108-- `Nothing`s.

88109renderCommaSeparatedMaybe

@@ -104,9 +125,21 @@ renderSymbol :: forall s. KnownSymbol s => ByteString

104125renderSymbol = fromString (symbolVal' (proxy# :: Proxy# s))

105126

106127-- | A class for rendering SQL

107−class RenderSQL sql where

108− renderSQL :: sql -> ByteString

128+class RenderSQL sql where renderSQL :: sql -> ByteString

109129

110130-- | Print SQL.

111−printSQL :: (RenderSQL sql, MonadBase IO io) => sql -> io ()

112−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+223−507

@@ -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−{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-}

1413{-# LANGUAGE

1514 AllowAmbiguousTypes

1615 , ConstraintKinds

@@ -22,6 +21,7 @@ it defines an embedding of Haskell types into Postgres types.

2221 , GADTs

2322 , LambdaCase

2423 , OverloadedStrings

24+ , QuantifiedConstraints

2525 , RankNTypes

2626 , ScopedTypeVariables

2727 , StandaloneDeriving

@@ -39,73 +39,48 @@ module Squeal.PostgreSQL.Schema

3939 , NullityType (..)

4040 , RowType

4141 , FromType

42− -- * Haskell to Postgres Types

43− , PG

44− , NullPG

45− , TuplePG

46− , RowPG

47− , Json (..)

48− , Jsonb (..)

49− , Composite (..)

50− , Enumerated (..)

5142 -- * Schema Types

5243 , ColumnType

5344 , ColumnsType

5445 , TableType

5546 , SchemumType (..)

47+ , IndexType (..)

48+ , FunctionType

49+ , OperatorType (..)

50+ , ReturnsType (..)

5651 , SchemaType

52+ , SchemasType

53+ , Public

5754 -- * Constraints

5855 , (:=>)

5956 , ColumnConstraint (..)

6057 , TableConstraint (..)

6158 , TableConstraints

6259 , Uniquely

63− -- * Aliases

64− , (:::)

65− , Alias (Alias)

66− , renderAlias

67− , renderAliases

68− , Aliased (As)

69− , Aliasable (as)

70− , renderAliasedAs

71− , Has

72− , HasUnique

73− , HasAll

74− , IsLabel (..)

75− , IsQualified (..)

76− , renderAliasString

7760 -- * Enumerated Labels

7861 , IsPGlabel (..)

7962 , PGlabel (..)

80− , renderLabel

81− , renderLabels

82− , LabelsPG

83− -- * Grouping

84− , Grouping (..)

85− , GroupedBy

86− -- * Aligned lists

87− , AlignedList (..)

88− , single

8963 -- * Data Definitions

9064 , Create

65+ , CreateIfNotExists

66+ , CreateOrReplace

9167 , Drop

68+ , DropSchemum

69+ , DropIfExists

70+ , DropSchemumIfExists

9271 , Alter

72+ , AlterIfExists

9373 , Rename

74+ , RenameIfExists

75+ , ConstraintInvolves

9476 , DropIfConstraintsInvolve

95− -- * Lists

96− , Join

97− , Elem

98− , In

99− , Length

77+ , IsNotElem

78+ , AllUnique

10079 -- * Type Classifications

101− , HasOid (..)

10280 , PGNum

10381 , PGIntegral

10482 , PGFloating

10583 , PGTypeOf

106− , PGArrayOf

107− , PGArray

108− , PGTextArray

10984 , PGJsonType

11085 , PGJsonKey

11186 , SamePGType

@@ -117,41 +92,27 @@ module Squeal.PostgreSQL.Schema

11792 , NullifyFrom

11893 -- * Table Conversions

11994 , TableToColumns

95+ , ColumnsToRow

12096 , TableToRow

12197 ) where

12298

12399import Control.Category

124−import Control.DeepSeq

125−import Data.Aeson (Value)

126−import Data.ByteString (ByteString)

127−import Data.Int (Int16, Int32, Int64)

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)

137−import Data.Vector (Vector)

138103import Generics.SOP

139−import Generics.SOP.Record

140−import GHC.OverloadedLabels

141104import GHC.TypeLits

142−import Network.IP.Addr

143105import Prelude hiding (id, (.))

144106

145−import qualified Data.ByteString.Lazy as Lazy

146−import qualified Data.Text.Lazy as Lazy

147−import qualified GHC.Generics as GHC

148−import qualified Generics.SOP.Type.Metadata as Type

149−

107+import Squeal.PostgreSQL.Alias

108+import Squeal.PostgreSQL.List

150109import Squeal.PostgreSQL.Render

151110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

152114-- | `PGType` is the promoted datakind of PostgreSQL types.

153115--

154−-- >>> import Squeal.PostgreSQL.Schema

155116-- >>> :kind 'PGbool

156117-- 'PGbool :: PGType

157118data PGType

@@ -162,6 +123,7 @@ data PGType

162123 | PGnumeric -- ^ arbitrary precision numeric type

163124 | PGfloat4 -- ^ single precision floating-point number (4 bytes)

164125 | PGfloat8 -- ^ double precision floating-point number (8 bytes)

126+ | PGmoney -- ^ currency amount

165127 | PGchar Nat -- ^ fixed-length character string

166128 | PGvarchar Nat -- ^ variable-length character string

167129 | PGtext -- ^ variable-length character string

@@ -177,39 +139,15 @@ data PGType

177139 | PGjson -- ^ textual JSON data

178140 | PGjsonb -- ^ binary JSON data, decomposed

179141 | PGvararray NullityType -- ^ variable length array

180− | PGfixarray Nat NullityType -- ^ fixed length array

142+ | PGfixarray [Nat] NullityType -- ^ fixed length array

181143 | PGenum [Symbol] -- ^ enumerated (enum) types are data types that comprise a static, ordered set of values.

182144 | 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).

183149 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types

184150

185−-- | The object identifier of a `PGType`.

186−--

187−-- >>> :set -XTypeApplications

188−-- >>> oid @'PGbool

189−-- 16

190−class HasOid (ty :: PGType) where oid :: Word32

191−instance HasOid 'PGbool where oid = 16

192−instance HasOid 'PGint2 where oid = 21

193−instance HasOid 'PGint4 where oid = 23

194−instance HasOid 'PGint8 where oid = 20

195−instance HasOid 'PGnumeric where oid = 1700

196−instance HasOid 'PGfloat4 where oid = 700

197−instance HasOid 'PGfloat8 where oid = 701

198−instance HasOid ('PGchar n) where oid = 18

199−instance HasOid ('PGvarchar n) where oid = 1043

200−instance HasOid 'PGtext where oid = 25

201−instance HasOid 'PGbytea where oid = 17

202−instance HasOid 'PGtimestamp where oid = 1114

203−instance HasOid 'PGtimestamptz where oid = 1184

204−instance HasOid 'PGdate where oid = 1082

205−instance HasOid 'PGtime where oid = 1083

206−instance HasOid 'PGtimetz where oid = 1266

207−instance HasOid 'PGinterval where oid = 1186

208−instance HasOid 'PGuuid where oid = 2950

209−instance HasOid 'PGinet where oid = 869

210−instance HasOid 'PGjson where oid = 114

211−instance HasOid 'PGjsonb where oid = 3802

212−

213151-- | `NullityType` encodes the potential presence or definite absence of a

214152-- @NULL@ allowing operations which are sensitive to such to be well typed.

215153--

@@ -228,11 +166,6 @@ data NullityType

228166type (:=>) constraint ty = '(constraint,ty)

229167infixr 7 :=>

230168

231−-- | The alias operator `:::` is like a promoted version of `As`,

232−-- a type level pair between an alias and some type.

233−type (:::) (alias :: Symbol) ty = '(alias,ty)

234−infixr 6 :::

235−

236169-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.

237170-- A column can be assigned a default value.

238171-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also

@@ -274,7 +207,13 @@ data TableConstraint

274207 | PrimaryKey [Symbol]

275208 | ForeignKey [Symbol] Symbol [Symbol]

276209

277−-- | 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+-}

278217type TableConstraints = [(Symbol,TableConstraint)]

279218

280219-- | A `ForeignKey` must reference columns that either are

@@ -300,7 +239,7 @@ type family Uniquely

300239type TableType = (TableConstraints,ColumnsType)

301240

302241{- | A `RowType` is a row of `NullityType`. They correspond to Haskell

303−record types by means of `RowPG` and are used in many places.

242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.

304243

305244>>> :{

306245type family PersonRow :: RowType where

@@ -321,9 +260,19 @@ type FromType = [(Symbol,RowType)]

321260

322261-- | `ColumnsToRow` removes column constraints.

323262type family ColumnsToRow (columns :: ColumnsType) :: RowType where

324− ColumnsToRow '[] = '[]

325− ColumnsToRow (column ::: constraint :=> ty ': columns) =

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) =

326274 column ::: ty ': ColumnsToRow columns

275+ ColumnsToRow '[] = '[]

327276

328277-- | `TableToColumns` removes table constraints.

329278type family TableToColumns (table :: TableType) :: ColumnsType where

@@ -333,153 +282,6 @@ type family TableToColumns (table :: TableType) :: ColumnsType where

333282type family TableToRow (table :: TableType) :: RowType where

334283 TableToRow tab = ColumnsToRow (TableToColumns tab)

335284

336−-- | `Grouping` is an auxiliary namespace, created by

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

338−-- for typesafe aggregation

339−data Grouping

340− = Ungrouped -- ^ no aggregation permitted

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

342−

343−{- | A `GroupedBy` constraint indicates that a table qualified column is

344−a member of the auxiliary namespace created by @GROUP BY@ clauses and thus,

345−may be called in an output `Squeal.PostgreSQL.Expression.Expression` without aggregating.

346−-}

347−class (KnownSymbol table, KnownSymbol column)

348− => GroupedBy table column bys where

349−instance {-# OVERLAPPING #-} (KnownSymbol table, KnownSymbol column)

350− => GroupedBy table column ('(table,column) ': bys)

351−instance {-# OVERLAPPABLE #-}

352− ( KnownSymbol table

353− , KnownSymbol column

354− , GroupedBy table column bys

355− ) => GroupedBy table column (tabcol ': bys)

356−

357−-- | `Alias`es are proxies for a type level string or `Symbol`

358−-- and have an `IsLabel` instance so that with @-XOverloadedLabels@

359−--

360−-- >>> :set -XOverloadedLabels

361−-- >>> #foobar :: Alias "foobar"

362−-- Alias

363−data Alias (alias :: Symbol) = Alias

364− deriving (Eq,GHC.Generic,Ord,Show,NFData)

365−instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where

366− fromLabel = Alias

367−instance aliases ~ '[alias] => IsLabel alias (NP Alias aliases) where

368− fromLabel = fromLabel :* Nil

369−instance KnownSymbol alias => RenderSQL (Alias alias) where renderSQL = renderAlias

370−

371−-- | >>> renderAlias #jimbob

372−-- "\"jimbob\""

373−renderAlias :: KnownSymbol alias => Alias alias -> ByteString

374−renderAlias = doubleQuoted . fromString . symbolVal

375−

376−-- | >>> renderAliasString #ohmahgerd

377−-- "'ohmahgerd'"

378−renderAliasString :: KnownSymbol alias => Alias alias -> ByteString

379−renderAliasString = singleQuotedText . fromString . symbolVal

380−

381−-- | >>> import Generics.SOP (NP(..))

382−-- >>> renderAliases (#jimbob :* #kandi)

383−-- ["\"jimbob\"","\"kandi\""]

384−renderAliases

385− :: All KnownSymbol aliases => NP Alias aliases -> [ByteString]

386−renderAliases = hcollapse

387− . hcmap (Proxy @KnownSymbol) (K . renderAlias)

388−

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

390−-- version of `:::`.

391−--

392−-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)

393−-- As (Just "hello") Alias

394−data Aliased expression aliased where

395− As

396− :: KnownSymbol alias

397− => expression ty

398− -> Alias alias

399− -> Aliased expression (alias ::: ty)

400−deriving instance Show (expression ty)

401− => Show (Aliased expression (alias ::: ty))

402−deriving instance Eq (expression ty)

403− => Eq (Aliased expression (alias ::: ty))

404−deriving instance Ord (expression ty)

405− => Ord (Aliased expression (alias ::: ty))

406−instance (alias0 ~ alias1, alias0 ~ alias2, KnownSymbol alias2)

407− => IsLabel alias0 (Aliased Alias (alias1 ::: alias2)) where

408− fromLabel = fromLabel @alias2 `As` fromLabel @alias1

409−

410−-- | The `Aliasable` class provides a way to scrap your `Nil`s

411−-- in an `NP` list of `Aliased` expressions.

412−class KnownSymbol alias => Aliasable alias expression aliased

413− | aliased -> expression

414− , aliased -> alias

415− where as :: expression -> Alias alias -> aliased

416−instance (KnownSymbol alias, alias ~ alias1) => Aliasable alias

417− (expression ty)

418− (Aliased expression (alias1 ::: ty))

419− where

420− as = As

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

422− (expression ty)

423− (NP (Aliased expression) tys)

424− where

425− expression `as` alias = expression `As` alias :* Nil

426−

427−-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")

428−-- >>> renderAliasedAs renderMaybe (Just (3::Int) `As` #an_int)

429−-- "Just AS \"an_int\""

430−renderAliasedAs

431− :: (forall ty. expression ty -> ByteString)

432− -> Aliased expression aliased

433− -> ByteString

434−renderAliasedAs render (expression `As` alias) =

435− render expression <> " AS " <> renderAlias alias

436−

437−-- | @HasUnique alias fields field@ is a constraint that proves that

438−-- @fields@ is a singleton of @alias ::: field@.

439−type HasUnique alias fields field = fields ~ '[alias ::: field]

440−

441−-- | @Has alias fields field@ is a constraint that proves that

442−-- @fields@ has a field of @alias ::: field@, inferring @field@

443−-- from @alias@ and @fields@.

444−class KnownSymbol alias =>

445− Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)

446− | alias fields -> field where

447−instance {-# OVERLAPPING #-} KnownSymbol alias

448− => Has alias (alias ::: field ': fields) field

449−instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)

450− => Has alias (field' ': fields) field

451−

452−-- | `HasAll` extends `Has` to take lists of @aliases@ and @fields@ and infer

453−-- a list of @subfields@.

454−class

455− ( All KnownSymbol aliases

456− ) => HasAll

457− (aliases :: [Symbol])

458− (fields :: [(Symbol,kind)])

459− (subfields :: [(Symbol,kind)])

460− | aliases fields -> subfields where

461−instance {-# OVERLAPPING #-} HasAll '[] fields '[]

462−instance {-# OVERLAPPABLE #-}

463− (Has alias fields field, HasAll aliases fields subfields)

464− => HasAll (alias ': aliases) fields (alias ::: field ': subfields)

465−

466−-- | Analagous to `IsLabel`, the constraint

467−-- `IsQualified` defines `!` for a column alias qualified

468−-- by a table alias.

469−class IsQualified table column expression where

470− (!) :: Alias table -> Alias column -> expression

471− infixl 9 !

472−instance IsQualified table column (Alias table, Alias column) where (!) = (,)

473−

474−-- | @Elem@ is a promoted `Data.List.elem`.

475−type family Elem x xs where

476− Elem x '[] = 'False

477− Elem x (x ': xs) = 'True

478− Elem x (_ ': xs) = Elem x xs

479−

480−-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.

481−type family In x xs :: Constraint where In x xs = Elem x xs ~ 'True

482−

483285-- | Numeric Postgres types.

484286type PGNum =

485287 '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

@@ -490,37 +292,6 @@ type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

490292-- | Integral Postgres types.

491293type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]

492294

493−-- | Error message helper for displaying unavailable\/unknown\/placeholder type

494−-- variables whose kind is known.

495−type Placeholder k = 'Text "(_::" :<>: 'ShowType k :<>: 'Text ")"

496−

497−type ErrArrayOf arr ty = arr :<>: 'Text " " :<>: ty

498−type ErrPGfixarrayOf t = ErrArrayOf ('ShowType 'PGfixarray :<>: 'Text " " :<>: Placeholder Nat) t

499−type ErrPGvararrayOf t = ErrArrayOf ('ShowType 'PGvararray) t

500−

501−-- | Ensure a type is a valid array type.

502−type family PGArray name arr :: Constraint where

503− PGArray name ('PGvararray x) = ()

504− PGArray name ('PGfixarray n x) = ()

505− PGArray name val = TypeError

506− ('Text name :<>: 'Text ": Unsatisfied PGArray constraint. Expected either: "

507− :$$: 'Text " • " :<>: ErrPGvararrayOf (Placeholder PGType)

508− :$$: 'Text " • " :<>: ErrPGfixarrayOf (Placeholder PGType)

509− :$$: 'Text "But got: " :<>: 'ShowType val)

510−

511−-- | Ensure a type is a valid array type with a specific element type.

512−type family PGArrayOf name arr ty :: Constraint where

513− PGArrayOf name ('PGvararray x) ty = x ~ ty

514− PGArrayOf name ('PGfixarray n x) ty = x ~ ty

515− PGArrayOf name val ty = TypeError

516− ( 'Text name :<>: 'Text "Unsatisfied PGArrayOf constraint. Expected either: "

517− :$$: 'Text " • " :<>: ErrPGvararrayOf ( 'ShowType ty )

518− :$$: 'Text " • " :<>: ErrPGfixarrayOf ( 'ShowType ty )

519− :$$: 'Text "But got: " :<>: 'ShowType val)

520−

521−-- | Ensure a type is a valid array type whose elements are text.

522−type PGTextArray name arr = PGArrayOf name arr ('NotNull 'PGtext)

523−

524295-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

525296type family PGTypeOf (ty :: NullityType) :: PGType where

526297 PGTypeOf (nullity pg) = pg

@@ -534,14 +305,24 @@ instance ty0 ~ ty1 => SamePGType

534305

535306-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.

536307type 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

537314 AllNotNull '[] = ()

538− AllNotNull (column ::: def :=> 'NotNull ty ': columns) = AllNotNull columns

539315

540316-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

541317-- @NOT NULL@.

542318type family NotAllNull (columns :: ColumnsType) :: Constraint where

543− NotAllNull (column ::: def :=> 'NotNull ty ': columns) = ()

544− NotAllNull (column ::: def :=> 'Null ty ': columns) = NotAllNull columns

319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

322+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

323+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

324+ NotAllNull (_ ::: _ :=> 'NotNull _ ': _) = ()

325+ NotAllNull (_ ::: _ :=> 'Null _ ': columns) = NotAllNull columns

545326

546327-- | `NullifyType` is an idempotent that nullifies a `NullityType`.

547328type family NullifyType (ty :: NullityType) :: NullityType where

@@ -550,23 +331,37 @@ type family NullifyType (ty :: NullityType) :: NullityType where

550331

551332-- | `NullifyRow` is an idempotent that nullifies a `RowType`.

552333type family NullifyRow (columns :: RowType) :: RowType where

553− NullifyRow '[] = '[]

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

554344 NullifyRow (column ::: ty ': columns) =

555345 column ::: NullifyType ty ': NullifyRow columns

346+ NullifyRow '[] = '[]

556347

557348-- | `NullifyFrom` is an idempotent that nullifies a `FromType`

558349-- used to nullify the left or right hand side of an outer join

559350-- in a `Squeal.PostgreSQL.Query.FromClause`.

560351type family NullifyFrom (tables :: FromType) :: FromType where

561− NullifyFrom '[] = '[]

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

562362 NullifyFrom (table ::: columns ': tables) =

563363 table ::: NullifyRow columns ': NullifyFrom tables

564−

565−-- | `Join` is simply promoted `++` and is used in @JOIN@s in

566−-- `Squeal.PostgreSQL.Query.FromClause`s.

567−type family Join xs ys where

568− Join '[] ys = ys

569− Join (x ': xs) ys = x ': Join xs ys

364+ NullifyFrom '[] = '[]

570365

571366-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in

572367-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

@@ -576,30 +371,101 @@ type family Create alias x xs where

576371 Create alias x (alias ::: y ': xs) = TypeError

577372 ('Text "Create: alias "

578373 ':<>: 'ShowType alias

579− ':<>: 'Text "already in use")

374+ ':<>: 'Text "already exists")

580375 Create alias y (x ': xs) = x ': Create alias y xs

581376

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+

582394-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

583395-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

584396-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

585397type family Drop alias xs where

586− 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

587403 Drop alias (x ': xs) = x ': Drop alias xs

588404

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+

589437-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@

590−-- 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`

591439-- and `Squeal.PostgreSQL.Definition.alterColumn`.

592440type family Alter alias x xs where

441+ Alter alias x '[] = TypeError

442+ ('Text "Alter: alias "

443+ ':<>: 'ShowType alias

444+ ':<>: 'Text " does not exist" )

593445 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

594446 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

595447

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

452+

596453-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@

597454-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

598455-- `Squeal.PostgreSQL.Definition.renameColumn`.

599456type family Rename alias0 alias1 xs where

457+ Rename alias0 alias1 '[] = TypeError

458+ ('Text "Rename: alias "

459+ ':<>: 'ShowType alias0

460+ ':<>: 'Text " does not exist" )

600461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

601462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

602463

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

468+

603469-- | Check if a `TableConstraint` involves a column

604470type family ConstraintInvolves column constraint where

605471 ConstraintInvolves column ('Check columns) = column `Elem` columns

@@ -616,22 +482,35 @@ type family DropIfConstraintsInvolve column constraints where

616482 (DropIfConstraintsInvolve column constraints)

617483 (alias ::: constraint ': DropIfConstraintsInvolve column constraints)

618484

619−{- | Calculate the `Length` of a type level list

620−

621−>>> :kind! Length '[Char,String,Bool,Double]

622−Length '[Char,String,Bool,Double] :: Nat

623−= 4

624−-}

625−type family Length (xs :: [k]) :: Nat where

626− Length (x : xs) = 1 + Length xs

627− Length '[] = 0

628−

629485-- | A `SchemumType` is a user-defined type, either a `Table`,

630486-- `View` or `Typedef`.

631487data SchemumType

632488 = Table TableType

633489 | View RowType

634490 | Typedef PGType

491+ | Index IndexType

492+ | Function FunctionType

493+ | Operator OperatorType

494+ | UnsafeSchemum Symbol

495+

496+type FunctionType = ([NullityType], ReturnsType)

497+

498+data IndexType

499+ = Btree

500+ | Hash

501+ | Gist

502+ | Spgist

503+ | Gin

504+ | Brin

505+

506+data ReturnsType

507+ = Returns NullityType

508+ | ReturnsTable RowType

509+

510+data OperatorType

511+ = BinaryOp NullityType NullityType NullityType

512+ | LeftOp NullityType NullityType

513+ | RightOp NullityType NullityType

635514

636515{- | The schema of a database consists of a list of aliased,

637516user-defined `SchemumType`s.

@@ -657,6 +536,27 @@ type family Schema :: SchemaType where

657536-}

658537type SchemaType = [(Symbol,SchemumType)]

659538

539+{- |

540+A database contains one or more named schemas, which in turn contain tables.

541+The same object name can be used in different schemas without conflict;

542+for example, both schema1 and myschema can contain tables named mytable.

543+Unlike databases, schemas are not rigidly separated:

544+a user can access objects in any of the schemas in the database they are connected to,

545+if they have privileges to do so.

546+

547+There are several reasons why one might want to use schemas:

548+

549+ * To allow many users to use one database without interfering with each other.

550+ * To organize database objects into logical groups to make them more manageable.

551+ * Third-party applications can be put into separate schemas

552+ so they do not collide with the names of other objects.

553+-}

554+type SchemasType = [(Symbol,SchemaType)]

555+

556+-- | A type family to use for a single schema database.

557+type family Public (schema :: SchemaType) :: SchemasType

558+ where Public schema = '["public" ::: schema]

559+

660560-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas

661561-- the overloaded label, `fromLabel` is used for column references,

662562-- `label`s are used for enum terms. A `label` is called with

@@ -668,195 +568,13 @@ instance labels ~ '[label]

668568 => IsPGlabel label (NP PGlabel labels) where label = PGlabel :* Nil

669569-- | A `PGlabel` unit type with an `IsPGlabel` instance

670570data PGlabel (label :: Symbol) = PGlabel

671−-- | Renders a label

672−renderLabel :: KnownSymbol label => proxy label -> ByteString

673−renderLabel (_ :: proxy label) =

674− "\'" <> renderSymbol @label <> "\'"

675−-- | Renders a list of labels

676−renderLabels

677− :: All KnownSymbol labels => NP PGlabel labels -> [ByteString]

678−renderLabels = hcollapse

679− . hcmap (Proxy @KnownSymbol) (K . renderLabel)

680−

681−{- | The `PG` type family embeds a subset of Haskell types

682−as Postgres types. As an open type family, `PG` is extensible.

683−

684−>>> :kind! PG LocalTime

685−PG LocalTime :: PGType

686−= 'PGtimestamp

687−

688−>>> newtype MyDouble = My Double

689−>>> type instance PG MyDouble = 'PGfloat8

690−-}

691−type family PG (hask :: Type) :: PGType

692−type instance PG Bool = 'PGbool

693−type instance PG Int16 = 'PGint2

694−type instance PG Int32 = 'PGint4

695−type instance PG Int64 = 'PGint8

696−type instance PG Word16 = 'PGint2

697−type instance PG Word32 = 'PGint4

698−type instance PG Word64 = 'PGint8

699−type instance PG Scientific = 'PGnumeric

700−type instance PG Float = 'PGfloat4

701−type instance PG Double = 'PGfloat8

702−type instance PG Char = 'PGchar 1

703−type instance PG Text = 'PGtext

704−type instance PG Lazy.Text = 'PGtext

705−type instance PG String = 'PGtext

706−type instance PG ByteString = 'PGbytea

707−type instance PG Lazy.ByteString = 'PGbytea

708−type instance PG LocalTime = 'PGtimestamp

709−type instance PG UTCTime = 'PGtimestamptz

710−type instance PG Day = 'PGdate

711−type instance PG TimeOfDay = 'PGtime

712−type instance PG (TimeOfDay, TimeZone) = 'PGtimetz

713−type instance PG DiffTime = 'PGinterval

714−type instance PG UUID = 'PGuuid

715−type instance PG (NetAddr IP) = 'PGinet

716−type instance PG Value = 'PGjson

717−type instance PG (Json hask) = 'PGjson

718−type instance PG (Jsonb hask) = 'PGjsonb

719−type instance PG (Vector hask) = 'PGvararray (NullPG hask)

720−type instance PG (hask, hask) = 'PGfixarray 2 (NullPG hask)

721−type instance PG (hask, hask, hask) = 'PGfixarray 3 (NullPG hask)

722−type instance PG (hask, hask, hask, hask) = 'PGfixarray 4 (NullPG hask)

723−type instance PG (hask, hask, hask, hask, hask) = 'PGfixarray 5 (NullPG hask)

724−type instance PG (hask, hask, hask, hask, hask, hask)

725− = 'PGfixarray 6 (NullPG hask)

726−type instance PG (hask, hask, hask, hask, hask, hask, hask)

727− = 'PGfixarray 7 (NullPG hask)

728−type instance PG (hask, hask, hask, hask, hask, hask, hask, hask)

729− = 'PGfixarray 8 (NullPG hask)

730−type instance PG (hask, hask, hask, hask, hask, hask, hask, hask, hask)

731− = 'PGfixarray 9 (NullPG hask)

732−type instance PG (hask, hask, hask, hask, hask, hask, hask, hask, hask, hask)

733− = 'PGfixarray 10 (NullPG hask)

734−type instance PG (Composite hask) = 'PGcomposite (RowPG hask)

735−type instance PG (Enumerated hask) = 'PGenum (LabelsPG hask)

736−

737−{- | The `Json` newtype is an indication that the Haskell

738−type it's applied to should be stored as `PGjson`.

739−-}

740−newtype Json hask = Json {getJson :: hask}

741− deriving (Eq, Ord, Show, Read, GHC.Generic)

742−

743−{- | The `Jsonb` newtype is an indication that the Haskell

744−type it's applied to should be stored as `PGjsonb`.

745−-}

746−newtype Jsonb hask = Jsonb {getJsonb :: hask}

747− deriving (Eq, Ord, Show, Read, GHC.Generic)

748−

749−{- | The `Composite` newtype is an indication that the Haskell

750−type it's applied to should be stored as a `PGcomposite`.

751−-}

752−newtype Composite record = Composite {getComposite :: record}

753− deriving (Eq, Ord, Show, Read, GHC.Generic)

754−

755−{- | The `Enumerated` newtype is an indication that the Haskell

756−type it's applied to should be stored as `PGenum`.

757−-}

758−newtype Enumerated enum = Enumerated {getEnumerated :: enum}

759− deriving (Eq, Ord, Show, Read, GHC.Generic)

760−

761−{-| The `LabelsPG` type family calculates the constructors of a

762−Haskell enum type.

763−

764−>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

765−>>> instance Generic Schwarma

766−>>> instance HasDatatypeInfo Schwarma

767−>>> :kind! LabelsPG Schwarma

768−LabelsPG Schwarma :: [Type.ConstructorName]

769−= '["Beef", "Lamb", "Chicken"]

770−-}

771−type family LabelsPG (hask :: Type) :: [Type.ConstructorName] where

772− LabelsPG hask =

773− ConstructorNamesOf (ConstructorsOf (DatatypeInfoOf hask))

774−

775−{- | `RowPG` turns a Haskell record type into a `RowType`.

776−

777−>>> data Person = Person { name :: Text, age :: Int32 } deriving GHC.Generic

778−>>> instance Generic Person

779−>>> instance HasDatatypeInfo Person

780−>>> :kind! RowPG Person

781−RowPG Person :: [(Symbol, NullityType)]

782−= '["name" ::: 'NotNull 'PGtext, "age" ::: 'NotNull 'PGint4]

783−-}

784−type family RowPG (hask :: Type) :: RowType where

785− RowPG hask = RowOf (RecordCodeOf hask)

786−

787−type family RowOf (fields :: [(Symbol, Type)]) :: RowType where

788− RowOf '[] = '[]

789− RowOf (field ': fields) = FieldPG field ': RowOf fields

790−

791−type family FieldPG (field :: (Symbol, Type)) :: (Symbol, NullityType) where

792− FieldPG (field ::: hask) = field ::: NullPG hask

793−

794−{- | `NullPG` turns a Haskell type into a `NullityType`.

795−

796−>>> :kind! NullPG Double

797−NullPG Double :: NullityType

798−= 'NotNull 'PGfloat8

799−>>> :kind! NullPG (Maybe Double)

800−NullPG (Maybe Double) :: NullityType

801−= 'Null 'PGfloat8

802−-}

803−type family NullPG (hask :: Type) :: NullityType where

804− NullPG (Maybe hask) = 'Null (PG hask)

805− NullPG hask = 'NotNull (PG hask)

806−

807−{- | `TuplePG` turns a Haskell tuple type (including record types) into

808−the corresponding list of `NullityType`s.

809−

810−>>> :kind! TuplePG (Double, Maybe Char)

811−TuplePG (Double, Maybe Char) :: [NullityType]

812−= '['NotNull 'PGfloat8, 'Null ('PGchar 1)]

813−-}

814−type family TuplePG (hask :: Type) :: [NullityType] where

815− TuplePG hask = TupleOf (TupleCodeOf hask (Code hask))

816−

817−type family TupleOf (tuple :: [Type]) :: [NullityType] where

818− TupleOf '[] = '[]

819− TupleOf (hask ': tuple) = NullPG hask ': TupleOf tuple

820−

821−type family TupleCodeOf (hask :: Type) (code :: [[Type]]) :: [Type] where

822− TupleCodeOf hask '[tuple] = tuple

823− TupleCodeOf hask '[] =

824− TypeError

825− ( 'Text "The type `" :<>: 'ShowType hask :<>: 'Text "' is not a tuple type."

826− :$$: 'Text "It is a void type with no constructors."

827− )

828− TupleCodeOf hask (_ ': _ ': _) =

829− TypeError

830− ( 'Text "The type `" :<>: 'ShowType hask :<>: 'Text "' is not a tuple type."

831− :$$: 'Text "It is a sum type with more than one constructor."

832− )

833−

834−-- | Calculates constructors of a datatype.

835−type family ConstructorsOf (datatype :: Type.DatatypeInfo)

836− :: [Type.ConstructorInfo] where

837− ConstructorsOf ('Type.ADT _module _datatype constructors) =

838− constructors

839− ConstructorsOf ('Type.Newtype _module _datatype constructor) =

840− '[constructor]

841−

842−-- | Calculates the name of a nullary constructor, otherwise

843−-- generates a type error.

844−type family ConstructorNameOf (constructors :: Type.ConstructorInfo)

845− :: Type.ConstructorName where

846− ConstructorNameOf ('Type.Constructor name) = name

847− ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

848− ('Text "ConstructorNameOf error: non-nullary constructor "

849− ':<>: 'Text name)

850− ConstructorNameOf ('Type.Record name _fields) = TypeError

851− ('Text "ConstructorNameOf error: non-nullary constructor "

852− ':<>: 'Text name)

853−

854−-- | Calculate the names of nullary constructors.

855−type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

856− :: [Type.ConstructorName] where

857− ConstructorNamesOf '[] = '[]

858− ConstructorNamesOf (constructor ': constructors) =

859− ConstructorNameOf constructor ': ConstructorNamesOf constructors

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)

860578

861579-- | Is a type a valid JSON key?

862580type PGJsonKey = '[ 'PGint2, 'PGint4, 'PGtext ]

@@ -864,17 +582,15 @@ type PGJsonKey = '[ 'PGint2, 'PGint4, 'PGtext ]

864582-- | Is a type a valid JSON type?

865583type PGJsonType = '[ 'PGjson, 'PGjsonb ]

866584

867−-- | An `AlignedList` is a type-aligned list or free category.

868−data AlignedList p x0 x1 where

869− Done :: AlignedList p x x

870− (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2

871−infixr 7 :>>

872−instance Category (AlignedList p) where

873− id = Done

874− (.) list = \case

875− Done -> list

876− step :>> steps -> step :>> (steps >>> list)

877−

878−-- | A `single` step.

879−single :: p x0 x1 -> AlignedList p x0 x1

880−single step = step :>> Done

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+98−73

@@ -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

@@ -20,89 +20,114 @@ module Squeal.PostgreSQL.Transaction

2020 ( -- * Transaction

2121 transactionally

2222 , transactionally_

23+ , transactionallyRetry

24+ , ephemerally

25+ , ephemerally_

2326 , begin

2427 , commit

2528 , rollback

26− , transactionallySchema

27− , transactionallySchema_

2829 -- * Transaction Mode

2930 , TransactionMode (..)

3031 , defaultMode

3132 , longRunningMode

3233 , IsolationLevel (..)

33− , renderIsolationLevel

3434 , AccessMode (..)

35− , renderAccessMode

3635 , DeferrableMode (..)

37− , renderDeferrableMode

3836 ) where

3937

40−import Control.Exception.Lifted

41−import Control.Monad.Base

42−import Control.Monad.Trans.Control

43−import Data.ByteString

44−import Data.Monoid

45−import Generics.SOP

46−

47−import qualified Database.PostgreSQL.LibPQ as LibPQ

38+import UnliftIO

4839

4940import Squeal.PostgreSQL.Manipulation

5041import Squeal.PostgreSQL.Render

5142import Squeal.PostgreSQL.PQ

52−import Squeal.PostgreSQL.Schema

5343

54−-- | 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+-}

5550transactionally

56− :: (MonadBaseControl IO tx, MonadPQ schema tx)

51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

5752 => TransactionMode

5853 -> tx x -- ^ run inside a transaction

5954 -> tx x

6055transactionally mode tx = mask $ \restore -> do

61− _ <- begin mode

62− result <- restore tx `onException` rollback

63− _ <- commit

56+ manipulate_ $ begin mode

57+ result <- restore tx `onException` (manipulate_ rollback)

58+ manipulate_ commit

6459 return result

6560

66−-- | Run a schema invariant computation `transactionally_` in `defaultMode`.

61+-- | Run a computation `transactionally_`, in `defaultMode`.

6762transactionally_

68− :: (MonadBaseControl IO tx, MonadPQ schema tx)

63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

6964 => tx x -- ^ run inside a transaction

7065 -> tx x

7166transactionally_ = transactionally defaultMode

7267

73−-- | @BEGIN@ a transaction.

74−begin :: MonadPQ schema tx => TransactionMode -> tx (K Result ('[] :: RowType))

75−begin mode = manipulate . UnsafeManipulation $

76− "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

77112

78−-- | @COMMIT@ a schema invariant transaction.

79−commit :: MonadPQ schema tx => tx (K Result ('[] :: RowType))

80−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

81123

82−-- | @ROLLBACK@ a schema invariant transaction.

83−rollback :: MonadPQ schema tx => tx (K Result ('[] :: RowType))

84−rollback = manipulate $ UnsafeManipulation "ROLLBACK;"

124+-- | @COMMIT@ a transaction.

125+commit :: Manipulation_ schemas () ()

126+commit = UnsafeManipulation "COMMIT"

85127

86−-- | Run a schema changing computation `transactionallySchema`.

87−transactionallySchema

88− :: MonadBaseControl IO io

89− => TransactionMode

90− -> PQ schema0 schema1 io x

91− -> PQ schema0 schema1 io x

92−transactionallySchema mode u = PQ $ \ conn -> mask $ \ restore -> do

93− _ <- liftBase . LibPQ.exec (unK conn) $

94− "BEGIN" <+> renderTransactionMode mode <> ";"

95− x <- restore (unPQ u conn)

96− `onException` (liftBase (LibPQ.exec (unK conn) "ROLLBACK"))

97− _ <- liftBase $ LibPQ.exec (unK conn) "COMMIT"

98− return x

99−

100−-- | Run a schema changing computation `transactionallySchema_` in `DefaultMode`.

101−transactionallySchema_

102− :: MonadBaseControl IO io

103− => PQ schema0 schema1 io x

104− -> PQ schema0 schema1 io x

105−transactionallySchema_ = transactionallySchema defaultMode

128+-- | @ROLLBACK@ a transaction.

129+rollback :: Manipulation_ schemas () ()

130+rollback = UnsafeManipulation "ROLLBACK"

106131

107132-- | The available transaction characteristics are the transaction `IsolationLevel`,

108133-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

@@ -115,7 +140,7 @@ data TransactionMode = TransactionMode

115140-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

116141-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

117142defaultMode :: TransactionMode

118−defaultMode = TransactionMode Serializable ReadWrite NotDeferrable

143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable

119144

120145-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

121146-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

@@ -124,12 +149,12 @@ longRunningMode :: TransactionMode

124149longRunningMode = TransactionMode Serializable ReadOnly Deferrable

125150

126151-- | Render a `TransactionMode`.

127−renderTransactionMode :: TransactionMode -> ByteString

128−renderTransactionMode mode =

129− "ISOLATION LEVEL"

130− <+> renderIsolationLevel (isolationLevel mode)

131− <+> renderAccessMode (accessMode mode)

132− <+> 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)

133158

134159-- | The SQL standard defines four levels of transaction isolation.

135160-- The most strict is `Serializable`, which is defined by the standard in a paragraph

@@ -180,12 +205,12 @@ data IsolationLevel

180205 deriving (Show, Eq)

181206

182207-- | Render an `IsolationLevel`.

183−renderIsolationLevel :: IsolationLevel -> ByteString

184−renderIsolationLevel = \case

185− Serializable -> "SERIALIZABLE"

186− ReadCommitted -> "READ COMMITTED"

187− ReadUncommitted -> "READ UNCOMMITTED"

188− 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"

189214

190215-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

191216-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

@@ -202,10 +227,10 @@ data AccessMode

202227 deriving (Show, Eq)

203228

204229-- | Render an `AccessMode`.

205−renderAccessMode :: AccessMode -> ByteString

206−renderAccessMode = \case

207− ReadWrite -> "READ WRITE"

208− ReadOnly -> "READ ONLY"

230+instance RenderSQL AccessMode where

231+ renderSQL = \case

232+ ReadWrite -> "READ WRITE"

233+ ReadOnly -> "READ ONLY"

209234

210235-- | The `Deferrable` transaction property has no effect

211236-- unless the transaction is also `Serializable` and `ReadOnly`.

@@ -221,7 +246,7 @@ data DeferrableMode

221246 deriving (Show, Eq)

222247

223248-- | Render a `DeferrableMode`.

224−renderDeferrableMode :: DeferrableMode -> ByteString

225−renderDeferrableMode = \case

226− Deferrable -> "DEFERRABLE"

227− 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-postgresql/test/Specs/ExceptionHandling.hsdeleted−121

@@ -1,121 +0,0 @@

1−{-# LANGUAGE DataKinds #-}

2−{-# LANGUAGE DeriveGeneric #-}

3−{-# LANGUAGE DuplicateRecordFields #-}

4−{-# LANGUAGE FlexibleContexts #-}

5−{-# LANGUAGE OverloadedLabels #-}

6−{-# LANGUAGE OverloadedLists #-}

7−{-# LANGUAGE OverloadedStrings #-}

8−{-# LANGUAGE TypeApplications #-}

9−{-# LANGUAGE TypeFamilies #-}

10−{-# LANGUAGE TypeOperators #-}

11−module ExceptionHandling

12− ( specs

13− , User (..)

14− )

15−where

16−

17−import Control.Monad (void)

18−import Control.Monad.Base (MonadBase)

19−import qualified Data.ByteString.Char8 as Char8

20−import Data.Int (Int16)

21−import Data.Text (Text)

22−import Data.Vector (Vector)

23−import qualified Generics.SOP as SOP

24−import qualified GHC.Generics as GHC

25−import Squeal.PostgreSQL

26−import Squeal.PostgreSQL.Migration

27−import Test.Hspec

28−

29−type Schema =

30− '[ "users" ::: 'Table (

31− '[ "pk_users" ::: 'PrimaryKey '["id"]

32− , "unique_names" ::: 'Unique '["name"]

33− ] :=>

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

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

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

37− ])

38− , "emails" ::: 'Table (

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

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

41− ] :=>

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

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

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

45− ])

46− ]

47−

48−data User =

49− User { userName :: Text

50− , userEmail :: Maybe Text

51− , userVec :: Vector (Maybe Int16) }

52− deriving (Show, GHC.Generic)

53−instance SOP.Generic User

54−instance SOP.HasDatatypeInfo User

55−

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

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

58−insertUser = insertRows #users

59− (Default `as` #id :* Set (param @1) `as` #name :* Set (param @2) `as` #vec) []

60− OnConflictDoRaise (Returning (#id `as` #fromOnly))

61−

62−setup :: Definition '[] Schema

63−setup =

64− createTable #users

65− ( serial `as` #id :*

66− (text & notNullable) `as` #name :*

67− (vararray int2 & notNullable) `as` #vec )

68− ( primaryKey #id `as` #pk_users

69− :* unique #name `as` #unique_names )

70− >>>

71− createTable #emails

72− ( serial `as` #id :*

73− (int & notNullable) `as` #user_id :*

74− (text & nullable) `as` #email )

75− ( primaryKey #id `as` #pk_emails :*

76− foreignKey #user_id #users #id

77− OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

78−

79−teardown :: Definition Schema '[]

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

81−

82−migration :: Migration IO '[] Schema

83−migration = Migration { name = "test"

84− , up = void $ define setup

85− , down = void $ define teardown }

86−

87−setupDB :: IO ()

88−setupDB = void . withConnection connectionString $

89− migrateUp $ single migration

90−

91−dropDB :: IO ()

92−dropDB = void . withConnection connectionString $

93− migrateDown $ single migration

94−

95−connectionString :: Char8.ByteString

96−connectionString = "host=localhost port=5432 dbname=exampledb"

97−

98−testUser :: User

99−testUser = User "TestUser" Nothing []

100−

101−newUser :: (MonadBase IO m, MonadPQ Schema m) => User -> m ()

102−newUser u = void $ manipulateParams insertUser (userName u, userVec u)

103−

104−insertUserTwice :: (MonadBase IO m, MonadPQ Schema m) => m ()

105−insertUserTwice = newUser testUser >> newUser testUser

106−

107−specs :: SpecWith ()

108−specs = before_ setupDB $ after_ dropDB $

109− describe "Exceptions" $ do

110−

111− let

112− dupKeyErr = PQException FatalError (Just "23505")

113− (Just "ERROR: duplicate key value violates unique constraint \"unique_names\"\nDETAIL: Key (name)=(TestUser) already exists.\n")

114−

115− it "should be thrown for unique constraint violation in a manipulation" $

116− withConnection connectionString insertUserTwice

117− `shouldThrow` (== dupKeyErr)

118−

119− it "should be rethrown for unique constraint violation in a manipulation by a transaction" $

120− withConnection connectionString (transactionally_ insertUserTwice)

121− `shouldThrow` (== dupKeyErr)

squeal-postgresql/test/Specs/Specs.hsdeleted−7

@@ -1,7 +0,0 @@

1−module Specs where

2−

3−import Test.Hspec

4−import qualified ExceptionHandling

5−

6−main :: IO ()

7−main = hspec ExceptionHandling.specs

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: nightly-2018-09-03

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