b259049..dev · squeal · git.iko.soy

git.iko.soy/squeal

53 files changed+11120−5131

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+818

@@ -1,5 +1,823 @@

11## RELEASE NOTES

3+### Version 0.5

5+Version 0.5 makes a number of large changes and additions to Squeal.

6+I want to thank folks who contributed issues and pull requests;

7+Raveline, rimmington, ilyakooo0, chshersh, reygoch, and more.

9+**Multi-schema support**

10+

11+Previous versions of Squeal only supported definitions in the "public"

12+schema. Squeal 0.5 adds support for multiple schemas with the new kind

13+

14+```Haskell

15+type SchemasType = [(Symbol,SchemaType)]

16+```

17+

18+In order to upgrade your queries, manipulations and definitions from

19+Squeal 0.4, you will have to apply the `Public` type family, which indicates

20+that your only schema is the "public" schema.

21+

22+```Haskell

23+-- Squeal 0.4

24+setup :: Definition '[] Schema

25+

26+-- Squeal 0.5

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

28+```

29+

30+You can create non-public schemas using `createSchema` and inversely

31+remove them using `dropSchema`. There is also an idempotent

32+`createSchemaIfNotExists`.

33+

34+In order to handle aliases which may refer to non-public schemas, Squeal 0.5

35+introduces `QualifiedAlias`es. A `QualifiedAlias` can be referred to using

36+the `(!)` operator from the `IsQualified` typeclass; but if you want to refer

37+to an alias from the "public" schema, you can continue to use a single

38+overloaded label, no need to write `#public ! #tab`, just write `#tab`.

39+

40+**Top-level statements**

41+

42+As a consequence of multi-schema support, common table expressions that

43+a `Query` or `Manipulation` may refer to had to be broken into a new parameter.

44+Additionally, `Query` gained another new parameter for its outer scope which

45+will be discussed in the next section.

46+

47+To simplify type signatures that you have to write for top-level queries

48+and manipulations, Squeal 0.5 introduces the `Query_` and `Manipulation_`

49+type families.

50+

51+```

52+type family Query_

53+ (schemas :: SchemasType)

54+ (parameters :: Type)

55+ (row :: Type) where

56+ Query_ schemas params row =

57+ Query '[] '[] schemas (TuplePG params) (RowPG row)

58+```

59+

60+As you see, a top-level `Query_` has no outer scope and no common

61+table expressions in scope, they are empty `'[]`. Moreover,

62+its parameters and row parameters are now `Type`s, which are

63+converted to corresponding Postgres types using the `TuplePG`

64+and `RowPG` type families. This means you can write the type signatures

65+for your top-level statements using the Haskell types that you

66+intend to input and retrieve when running the statements. Similar

67+to `Query_`, there is a `Manipulation_` type, the only difference

68+being that a general `Manipulation` doesn't have an outer scope,

69+only a scope for common table expressions.

70+

71+**Subquery expressions**

72+

73+Previous versions of Squeal offered subquery expression support

74+but there were issues. The common use case of using the `IN` operator

75+from SQL was overly complex. There was a proliferation of subquery

76+functions to handle different comparison operators, each with two versions

77+for comparing `ALL` or `ANY` of the query rows. And, most confoundedly,

78+there was no way to support the `EXISTS` subquery because the "outer scope"

79+for a query was not available.

80+

81+Squeal adds an outer scope to the `Query` type.

82+

83+```Haskell

84+newtype Query

85+ (outer :: FromType)

86+ (commons :: FromType)

87+ (schemas :: SchemasType)

88+ (params :: [NullityType])

89+ (row :: RowType)

90+ = UnsafeQuery { renderQuery :: ByteString }

91+```

92+

93+This enables a well-typed `exists` function.

94+

95+```Haskell

96+exists

97+ :: Query (Join outer from) commons schemas params row

98+ -> Condition outer commons grp schemas params from

99+```

100+

101+The `in_` and `notIn` functions were simplified to handle the most

102+common use case of comparing to a list of values.

103+

104+```Haskell

105+in_

106+ :: Expression outer commons grp schemas params from ty -- ^ expression

107+ -> [Expression outer commons grp schemas params from ty]

108+ -> Condition outer commons grp schemas params from

109+```

110+

111+Finally, general subquery comparisons were abstracted to work with

112+any comparison operators, using the `Operator` type which will be discussed in

113+the next section.

114+

115+```Haskell

116+subAll

117+ :: Expression outer commons grp schemas params from ty1

118+ -> Operator ty1 ty2 ('Null 'PGbool)

119+ -> Query (Join outer from) commons schemas params '[col ::: ty2]

120+ -> Condition outer commons grp schemas params from

121+

122+subAny

123+ :: Expression outer commons grp schemas params from ty1

124+ -> Operator ty1 ty2 ('Null 'PGbool)

125+ -> Query (Join outer from) commons schemas params '[col ::: ty2]

126+ -> Condition outer commons grp schemas params from

127+```

128+

129+**Expression RankNTypes**

130+

131+Squeal 0.5 introduces RankNType type synonyms for common expression patterns.

132+The simplest example is the `Expr` type, a type for "closed" expressions

133+that cannot reference any aliases or parameters.

134+

135+```Haskell

136+type Expr x

137+ = forall outer commons grp schemas params from

138+ . Expression outer commons grp schemas params from x

139+```

140+

141+There is also a function type `(-->)`, which is a subtype of the usual Haskell function

142+type `(->)`.

143+

144+```Haskell

145+type (-->) x y

146+ = forall outer commons grp schemas params from

147+ . Expression outer commons grp schemas params from x

148+ -> Expression outer commons grp schemas params from y

149+```

150+

151+We saw in the subquery section that there is an `Operator` type.

152+

153+```Haskell

154+type Operator x1 x2 y

155+ = forall outer commons grp schemas params from

156+ . Expression outer commons grp schemas params from x1

157+ -> Expression outer commons grp schemas params from x2

158+ -> Expression outer commons grp schemas params from y

159+```

160+

161+There are also types `FunctionN` and `FunctionVar` for n-ary functions

162+and variadic functions.

163+

164+```

165+type FunctionN xs y

166+ = forall outer commons grp schemas params from

167+ . NP (Expression outer commons grp schemas params from) xs

168+ -> Expression outer commons grp schemas params from y

169+```

170+

171+An n-ary function takes an `NP` list of `Expression`s as its argument.

172+Squeal 0.5 adds a helpful operator `(*:)`, to help scrap your `Nil`s.

173+You can construct an `NP` list now by using the operator `(:*)`,

174+until your last element, using `(*:)` there. For instance, the function

175+`atan2_` takes two arguments, `atan2_ (pi *: 2)`.

176+

177+**Selections**

178+

179+Previously, Squeal provided a couple versions of `SELECT` depending

180+on whether you wanted to select all columns of a unique table

181+in the from clause, i.e. `*`, all columns of a particular table

182+in the from clause, i.e. `.*`, or a list of columns from the from clause.

183+

184+Squeal 0.5 refactors this pattern into a `Selection` GADT type, allowing

185+for abstraction and combinations that were not possible before.

186+

187+```Haskell

188+data Selection outer commons grp schemas params from row where

189+ Star

190+ :: HasUnique tab from row

191+ => Selection outer commons 'Ungrouped schemas params from row

192+ DotStar

193+ :: Has tab from row

194+ => Alias tab

195+ -> Selection outer commons 'Ungrouped schemas params from row

196+ List

197+ :: SListI row

198+ => NP (Aliased (Expression outer commons grp schemas params from)) row

199+ -> Selection outer commons grp schemas params from row

200+ Over

201+ :: SListI row

202+ => NP (Aliased (WindowFunction outer commons grp schemas params from)) row

203+ -> WindowDefinition outer commons grp schemas params from

204+ -> Selection outer commons grp schemas params from row

205+ Also

206+ :: Selection outer commons grp schemas params from right

207+ -> Selection outer commons grp schemas params from left

208+ -> Selection outer commons grp schemas params from (Join left right)

209+```

210+

211+In addition to the `Star`, `DotStar` and `List` constructors, there is an

212+`Also` constructor combinator, which enables users to combine `Selection`s.

213+Additionally, there is an `Over` constructor that is used to enable

214+window functions, described in the next section.

215+

216+To upgrade from Squeal 0.4, you will replace `selectStar` with `select Star`,

217+replace `selectDotStar #tab` with `select (DotStar #tab)`. The `List`

218+selection is such a common use case that there is a function `select_` which

219+automatically applies it, so to upgrade from Squeal 0.4, replace `select`

220+with `select_`. There are also independent `selectDistinct` and `selectDistinct_`

221+functions to filter out duplicate rows.

222+

223+**Query clauses**

224+

225+Previously, Squeal provided a couple versions of `INSERT` depending

226+on whether you wanted to insert `VALUES` or a query.

227+

228+Squeal 0.5 refactors this pattern into a `QueryClause` GADT.

229+

230+```

231+-- Squeal 0.4

232+insertRow_ #tab (Set 2 `as` #col1 :* Default `as` #col2)

233+insertQuery_ #tab (selectStar (from (table #other_tab)))

234+

235+-- Squeal 0.5

236+insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))

237+insertInto_ #tab (Subquery (select Star (from (table #other_tab))))

238+```

239+

240+**Window functions and aggregation**

241+

242+Previous versions of Squeal provided no support for window functions.

243+Squeal 0.5 adds support for window functions. We saw `Over` in the

244+previous section.

245+

246+```Haskell

247+Over

248+ :: SListI row

249+ => NP (Aliased (WindowFunction outer commons grp schemas params from)) row

250+ -> WindowDefinition outer commons grp schemas params from

251+ -> Selection outer commons grp schemas params from row

252+```

253+

254+`Over` combines window functions with window definitions. A `WindowDefinition`

255+is constructed using the `partitionBy` function, optionally with an `orderBy`

256+clause. For example,

257+

258+```Haskell

259+query :: Query_ (Public Schema) () (Row Int32 Int32)

260+query = select

261+ (#col1 & Also (rank `as` #col2 `Over` (partitionBy #col1 & orderBy [#col2 & Asc])))

262+ (from (table #tab))

263+```

264+

265+Here the `rank` function is a `WindowFunction`

266+

267+```Haskell

268+rank :: WinFun0 ('NotNull 'PGint8)

269+rank = UnsafeWindowFunction "rank()"

270+```

271+

272+`WinFun0` is a RankNType, like `Expr` was, used for no argument window functions.

273+Similarly, there are also `WinFun1` and `WinFunN` types for

274+window functions and n-ary window functions.

275+

276+In order to use the same syntax for certain window functions and aggregate functions,

277+a new typeclass `Aggregate` was introduced. So for instance, `sum_` can be

278+either a `Distinction` `Expression` or a `WindowFunction`, used either with

279+a `groupBy` or with a `partitionBy` in the appropriate way.

280+

281+```

282+data Distinction (expr :: kind -> Type) (ty :: kind)

283+ = All (expr ty)

284+ | Distinct (expr ty)

285+```

286+

287+Aggregate functions can be run over all rows or only over distinct rows,

288+while window functions bear no such distinction.

289+

290+**Migrations**

291+

292+Thanks to [https://github.com/Raveline](Raveline) Squeal 0.5 introduces

293+a function `defaultMain` to easily create a command line program to

294+run or rewind your migrations.

295+

296+Previously, Squeal's migrations were impure, allowing in addition to

297+running `Definition`s to run arbitrary `IO` operations, such as inserting

298+data into the database or printing out status messages. In order to

299+provide compatibility with other migration systems, Squeal 0.5 introduces

300+pure migrations, that is migrations that are only `Definition`s.

301+

302+```Haskell

303+data Migration p schemas0 schemas1 = Migration

304+ { name :: Text -- ^ The `name` of a `Migration`.

305+ -- Each `name` in a `Migration` should be unique.

306+ , up :: p schemas0 schemas1 -- ^ The `up` instruction of a `Migration`.

307+ , down :: p schemas1 schemas0 -- ^ The `down` instruction of a `Migration`.

308+ } deriving (GHC.Generic)

309+```

310+

311+A pure migration is a `Migration Definition`, a pair of inverse

312+`Definition`s with a unique name. To recover impure migrations, Squeal 0.5

313+introduces the `Terminally` type.

314+

315+```Haskell

316+newtype Terminally trans monad x0 x1 = Terminally

317+ { runTerminally :: trans x0 x1 monad () }

318+```

319+

320+`Terminally` applies the indexed monad transformer and the monad it transforms

321+to the unit type `()`, thereby turning an indexed monad into a `Category`. An

322+impure migration is a `Migration (Terminally PQ IO)`. You can always cast

323+a pure migration into an impure migration with the functor, `pureMigration`.

324+

325+```Haskell

326+pureMigration

327+ :: Migration Definition schemas0 schemas1

328+ -> Migration (Terminally PQ IO) schemas0 schemas1

329+```

330+

331+To run either pure or impure migrations, Squeal 0.5 introduces

332+a typeclass, `Migratory`.

333+

334+```

335+class Category p => Migratory p where

336+

337+ migrateUp

338+ :: AlignedList (Migration p) schemas0 schemas1

339+ -> PQ schemas0 schemas1 IO ()

340+

341+ migrateDown

342+ :: AlignedList (Migration p) schemas0 schemas1

343+ -> PQ schemas1 schemas0 IO ()

344+```

345+

346+The signatures of `migrateUp` and `migrateDown` have been changed

347+to make them easier to compose with other `PQ` actions.

348+

349+**Transactions**

350+

351+You can now run transactions `ephemerally`, guaranteed to roll back,

352+but return the result or throw the exception that the transaction

353+would have generated. This is useful for testing. You can also

354+`transactionallyRetry` computations, retrying the transaction if

355+a [serialization failure](https://www.postgresql.org/docs/11/transaction-iso.html#XACT-REPEATABLE-READ) occurs.

356+

357+**Types**

358+

359+Squeal now supports money via a `Money` Haskell `Type` and a `'PGmoney`

360+`PGType`. Squeal 0.5 also adds support for creating domain types

361+with `createDomain`.

362+

363+**Time**

364+

365+Squeal 0.5 adds support for new functions; `now`, `makeDate`, `makeTime`,

366+, `makeTimestamp`, and `makeTimestamptz`, a function `interval_` for

367+constructing time intervals out multiples of `TimeUnit`s, and a new

368+`TimeOp` class, defining affine space operators for time types and their

369+differences.

370+

371+**Literals**

372+

373+Squeal allows you to include Haskell values in your statements using

374+out of line `parameter`s, but often you want to include them inline,

375+as a SQL `literal`. Squeal 0.5 enables this using the `Literal` class.

376+

377+**Set returning functions**

378+

379+Squeal 0.5 adds support for set returning functions such as `unnest`,

380+with the `RankNType` `SetOfFunction`, which can be used as as a `FromClause`.

381+

382+**Text search**

383+

384+Squeal 0.5 adds extensive support for text search types, functions and operators.

385+

386+**Much more**

387+

388+Lots more changes went into and under the hood of the new version.

389+The `Expression` module was split into coherent submodules since it

390+had grown to immense proportions. New modules `Alias`, `PG` and `List`

391+were added to relieve some of the burden that the `Schema` module

392+had been carrying. Rendering has been better unified with a new

393+`RenderSQL` typeclass. Type level list concatenation with the `Additional`

394+typeclass has been added. `Manipulation`s `update` and `delete`

395+were upgraded, so you can leave out fields you don't want to update and

396+use `USING` clauses in deletes. Upserts which were previously broken

397+now work. The `IO` typeclass hierarchy was changed from `MonadBase`

398+and `MonadBaseControl` to `MonadIO` and `MonadUnliftIO`. A new

399+`withRecursive` `Manipulation` was added. `SquealException`s were

400+refactored and a `trySqueal` function added. Arrays were refactored.

401+And there was probably more I've forgotten.

402+

403+### Version 0.4

404+

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

406+support for multidimensional arrays, improves support

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

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

409+adds subquery expressions, and adds table and view type expressions.

410+

411+**Types**

412+

413+Squeal 0.4 renames some kinds to aid intuition:

414+

415+```Haskell

416+type RowType = [(Symbol, NullityType)] -- previously RelationType

417+type FromType = [(Symbol, RowType)] -- previously RelationsType

418+```

419+

420+Null safety for array and composite types is gained by having the base

421+type of an array be a `NullityType` and the base type of a composite

422+a `RowType`.

423+

424+```Haskell

425+data PGType

426+ = ..

427+ | PGvararray NullityType

428+ | PGfixarray Nat NullityType

429+ | PGcomposite RowType

430+```

431+

432+Squeal embeds Postgres types into Haskell using data kinds and type-in-type:

433+

434+```Haskell

435+data PGType = PGbool | ..

436+data NullityType = Null PGType | NotNull PGType

437+type RowType = [(Symbol, NullityType)] -- previously RelationType

438+type FromType = [(Symbol, RowType)] -- previously RelationsType

439+```

440+

441+In another sense, we can embed Haskell types

442+into Postgres types by providing type families:

443+

444+```Haskell

445+type family PG (hask :: Type) :: PGType

446+type family NullPG (hask :: Type) :: NullityType

447+type family TuplePG (hask :: Type) :: [NullityType]

448+type family RowPG (hask :: Type) :: RowType

449+```

450+

451+Let's look at these one by one.

452+

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

454+associates some Haskell types to their obvious corresponding Postgres

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

456+no arrays or composites. Squeal 0.4 extends it to

457+such container types and makes it an open type family so that

458+users can make their own type instances.

459+

460+`NullPG` had a different name before but it does the obvious

461+thing for Haskell with `Maybe`s:

462+

463+```Haskell

464+type family NullPG hask where

465+ NullPG (Maybe hask) = 'Null (PG hask)

466+ NullPG hask = 'NotNull (PG hask)

467+```

468+

469+`TuplePG` uses generics to turn tuple types (including records)

470+into lists of `NullityType`s in the logical way, e.g.

471+`TuplePG (Bool, Day) = '[ 'PGbool, 'PGdate]`.

472+

473+`RowPG` also uses generics to turn record types into a `RowType` in the logical way, e.g.

474+

475+```Haskell

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

477+>>> instance SOP.Generic Person

478+>>> instance SOP.HasDatatypeInfo Person

479+>>> :kind! TuplePG Person

480+TuplePG Person :: [NullityType]

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

482+>>> :kind! RowPG Person

483+RowPG Person :: [(Symbol, NullityType)]

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

485+```

486+

487+We've already seen a hint of why these types are useful in one construction

488+from Squeal 0.3. Creating composite types in Postgres directly from a Haskell

489+record type essentially uses `RowPG`. Another important use is in simplifying

490+the type signatures for a `Query` or `Manipulation`. Very often, you will have

491+a tuple type corresponding to the parameters and a record type corresponding

492+to the returned columns of a `Query` or `Manipulation`. Instead of writing

493+boilerplate signature you can reuse these with the help of `TuplePG` and `RowPG`

494+

495+For instance:

496+

497+```Haskell

498+>>> :{

499+let

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

501+ query = selectStar (from (view #user) & where_ (#age .> param @1))

502+:}

503+```

504+

505+**Arrays**

506+

507+In addition to being able to encode and decode basic Haskell types

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

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

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

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

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

513+

514+```Haskell

515+>>> :{

516+data Row = Row

517+ { col1 :: Vector Int16

518+ , col2 :: (Maybe Int16,Maybe Int16)

519+ , col3 :: ((Int16,Int16),(Int16,Int16),(Int16,Int16))

520+ } deriving (Eq, GHC.Generic)

521+:}

522+

523+>>> instance Generic Row

524+>>> instance HasDatatypeInfo Row

525+```

526+

527+Define a simple round trip query.

528+

529+```Haskell

530+>>> :{

531+let

532+ roundTrip :: Query '[] (TuplePG Row) (RowPG Row)

533+ roundTrip = values_ $

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

535+ parameter @2 (int2 & fixarray @2) `as` #col2 :*

536+ parameter @3 (int2 & fixarray @2 & fixarray @3) `as` #col3

537+:}

538+

539+>>> :set -XOverloadedLists

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

541+>>> :{

542+void . withConnection "host=localhost port=5432 dbname=exampledb" $ do

543+ result <- runQueryParams roundTrip input

544+ Just output <- firstRow result

545+ liftBase . print $ input == output

546+:}

547+True

548+```

549+

550+**Containers**

551+

552+Squeal aims to provide a correspondence between Haskell types and Postgres types.

553+In particular, Haskell ADTs with nullary constructors can correspond to

554+Postgres enum types and Haskell record types can correspond to Postgres

555+composite types. However, it's not always obvious that that's how a user

556+will choose to store values of those types. So Squeal 0.4 introduces newtypes

557+whose purpose is to specify how a user wants to store values of a type.

558+

559+```Haskell

560+newtype Json hask = Json {getJson :: hask}

561+newtype Jsonb hask = Jsonb {getJsonb :: hask}

562+newtype Composite record = Composite {getComposite :: record}

563+newtype Enumerated enum = Enumerated {getEnumerated :: enum}

564+```

565+

566+Let's see an example:

567+

568+```Haskell

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

570+>>> instance SOP.Generic Schwarma

571+>>> instance SOP.HasDatatypeInfo Schwarma

572+>>>

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

574+>>> instance SOP.Generic Person

575+>>> instance SOP.HasDatatypeInfo Person

576+>>> instance Aeson.FromJSON Person

577+>>> instance Aeson.ToJSON Person

578+```

579+

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

581+

582+```Haskell

583+>>> :{

584+type Schema =

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

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

587+ ]

588+:}

589+

590+>>> :{

591+let

592+ setup :: Definition '[] Schema

593+ setup =

594+ createTypeEnumFrom @Schwarma #schwarma >>>

595+ createTypeCompositeFrom @Person #person

596+:}

597+```

598+

599+Let's demonstrate how to associate our Haskell types `Schwarma` and `Person`

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

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

602+

603+```Haskell

604+>>> :{

605+data Row = Row

606+ { schwarma :: Enumerated Schwarma

607+ , person1 :: Composite Person

608+ , person2 :: Json Person

609+ } deriving (Eq, GHC.Generic)

610+:}

611+

612+>>> instance Generic Row

613+>>> instance HasDatatypeInfo Row

614+>>> :{

615+let

616+ input = Row

617+ (Enumerated Chicken)

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

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

620+:}

621+```

622+

623+Once again, define a round trip query.

624+

625+```Haskell

626+>>> :{

627+let

628+ roundTrip :: Query Schema (TuplePG Row) (RowPG Row)

629+ roundTrip = values_ $

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

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

632+ parameter @3 json `as` #person2

633+:}

634+```

635+

636+Finally, we can drop our type definitions.

637+

638+```Haskell

639+>>> :{

640+let

641+ teardown :: Definition Schema '[]

642+ teardown = dropType #schwarma >>> dropType #person

643+:}

644+```

645+

646+Now let's run it.

647+

648+```Haskell

649+>>> :{

650+let

651+ session = do

652+ result <- runQueryParams roundTrip input

653+ Just output <- firstRow result

654+ liftBase . print $ input == output

655+in

656+ void . withConnection "host=localhost port=5432 dbname=exampledb" $

657+ define setup

658+ & pqThen session

659+ & pqThen (define teardown)

660+:}

661+True

662+```

663+

664+**With**

665+

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

667+Here's the type signature for `with` in Squeal 0.3.

668+

669+```Haskell

670+with

671+ :: SOP.SListI commons

672+ => NP (Aliased (Manipulation schema params)) (common ': commons)

673+ -- ^ common table expressions

674+ -> Manipulation (With (common ': commons) schema) params results

675+ -> Manipulation schema params results

676+```

677+

678+The first problem is that `with` only works with `Manipulations`.

679+It can work on `Query`s by using `queryStatement` but it still will

680+return a `Manipulation`. We can fix this issue by making `with` a

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

682+

683+The second problem is that all the common table expressions

684+refer the base schema, whereas in SQL, each subsequent CTE can

685+refer to previous CTEs as well. But this can be fixed! First define a datatype:

686+

687+```Haskell

688+data CommonTableExpression statement params schema0 schema1 where

689+ CommonTableExpression

690+ :: Aliased (statement schema params) (alias ::: cte)

691+ -> CommonTableExpression statement params schema (alias ::: 'View cte ': schema)

692+```

693+

694+It's just a wrapper around an aliased statement, where the statement

695+could be either a `Query` or `Manipulation`, but it augments the schema

696+by adding a view to it. It almost looks like a morphism between schemas

697+but there is no way yet to compose them. Luckily, Squeal already has

698+a datatype for this, which is used for migrations, the `AlignedList`

699+type which is really the "free category". So we can then define a `With` type class:

700+

701+```Haskell

702+class With statement where

703+ with

704+ :: AlignedList (CommonTableExpression statement params) schema0 schema1

705+ -> statement schema1 params row

706+ -> statement schema0 params row

707+```

708+

709+By giving `Aliasable` instances to CTEs and aligned singleton lists of CTEs (i.e. scrap-your-nils), we get a nice syntax for WITH statements in Squeal.

710+

711+Here's an example of using `with` for a `Query` and a `Manipulation`:

712+

713+```Haskell

714+>>> :{

715+let

716+ query :: Query

717+ '[ "t1" ::: 'View

718+ '[ "c1" ::: 'NotNull 'PGtext

719+ , "c2" ::: 'NotNull 'PGtext] ]

720+ '[]

721+ '[ "c1" ::: 'NotNull 'PGtext

722+ , "c2" ::: 'NotNull 'PGtext ]

723+ query = with (

724+ selectStar (from (view #t1)) `as` #t2 :>>

725+ selectStar (from (view #t2)) `as` #t3

726+ ) (selectStar (from (view #t3)))

727+in printSQL query

728+:}

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

730+

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

732+

733+>>> :{

734+let

735+ manipulation :: Manipulation

736+ '[ "products" ::: 'Table ProductsTable

737+ , "products_deleted" ::: 'Table ProductsTable

738+ ] '[ 'NotNull 'PGdate] '[]

739+ manipulation = with

740+ (deleteFrom #products (#date .< param @1) ReturningStar `as` #deleted_rows)

741+ (insertQuery_ #products_deleted (selectStar (from (view (#deleted_rows `as` #t)))))

742+in printSQL manipulation

743+:}

744+WITH "deleted_rows" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "deleted_rows" AS "t"

745+```

746+

747+**Three Valued Logic**

748+

749+In previous versions of Squeal, conditions followed classical two valued logic

750+of `true` and `false`.

751+

752+```Haskell

753+-- Squeal 0.3

754+type Condition schema from grouping params =

755+ Expression schema from grouping params ('NotNull 'PGbool)

756+```

757+

758+I had thought that three valued logic, which is what SQL uses, was confusing.

759+However, multiple users reported being confused at being forced to do `NULL`

760+handling, particularly in their left joins. Since the original motivation

761+of being less confusing evaporated I decided to switch to three valued logic

762+of `true`, `false` and `null_`.

763+

764+```Haskell

765+-- Squeal 0.4

766+type Condition schema from grouping params =

767+ Expression schema from grouping params ('Null 'PGbool)

768+```

769+

770+**Subquery Expressions**

771+

772+Squeal 0.4 adds support for subquery expressions such as `IN` and `op ANY/ALL`.

773+

774+**Row Types**

775+

776+Squeal 0.4 adds functions to define type expressions from tables and views

777+and a type expression for user defined types, `typetable`, `typeview` and

778+`typedef`.

779+

780+**Runtime Exceptions**

781+

782+Squeal now has an exception type which gives details on the sort of error

783+encountered and handler functions.

784+

785+```Haskell

786+data SquealException

787+ = PQException

788+ { sqlExecStatus :: LibPQ.ExecStatus

789+ , sqlStateCode :: Maybe ByteString

790+ -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html

791+ , sqlErrorMessage :: Maybe ByteString

792+ }

793+ | ResultException Text

794+ | ParseException Text

795+ deriving (Eq, Show)

796+instance Exception SquealException

797+

798+catchSqueal

799+ :: MonadBaseControl IO io

800+ => io a

801+ -> (SquealException -> io a) -- ^ handler

802+ -> io a

803+

804+handleSqueal

805+ :: MonadBaseControl IO io

806+ => (SquealException -> io a) -- ^ handler

807+ -> io a -> io a

808+```

809+

810+**Additional Changes**

811+

812+Squeal 0.4 adds `field` and `index` functions to get components of composite

813+and array expressions.

814+

815+Squeal 0.4 adds a dependency on `records-sop` to offload a lot of boilerplate

816+type family logic that was needed for `RowPG`.

817+

818+The above changes required major and minor changes to Squeal DSL functions.

819+Please consult the documentation.

820+

3821### Version 0.3.2 - August 4, 2018

4822

5823Version 0.3.2 features extensive support for `JSON` functionality with

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+59−18

@@ -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

@@ -37,59 +65,73 @@ library

3765 ghc-options: -Wall

3866 build-depends:

3967 aeson >= 1.2.4.0

40− , base >= 4.10.1.0 && < 5.0

68+ , base >= 4.11.1.0 && < 5.0

4169 , binary-parser >= 0.5.5

4270 , bytestring >= 0.10.8.2

4371 , bytestring-strict-builder >= 0.4.5

4472 , deepseq >= 1.4.3.0

45− , generics-sop >= 0.3.2.0

46− , lifted-base >= 0.2.3.12

73+ , free-categories >= 0.1.0.0

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

4775 , mmorph >= 1.1.1

48− , monad-control >= 1.0.2.3

4976 , mtl >= 2.2.2

5077 , network-ip >= 0.3.0.2

5178 , postgresql-binary >= 0.12.1

5279 , postgresql-libpq >= 0.9.4.1

53− , profunctors >= 5.2.2

5480 , records-sop >= 0.1.0.0

5581 , resource-pool >= 0.2.3.2

5682 , scientific >= 0.3.5.3

5783 , text >= 1.2.3.0

5884 , time >= 1.8.0.2

5985 , transformers >= 0.5.2.0

60− , transformers-base >= 0.4.4

86+ , unliftio >= 0.2.10

87+ , unliftio-pool >= 0.2.1.0

6188 , uuid-types >= 1.0.3

6289 , vector >= 0.12.0.1

6390

64−test-suite squeal-postgresql-doctest

91+test-suite doctest

6592 default-language: Haskell2010

6693 type: exitcode-stdio-1.0

6794 hs-source-dirs: test

6895 ghc-options: -Wall

69− main-is: DocTest.hs

96+ main-is: Doc.hs

7097 build-depends:

7198 base >= 4.10.0.0

7299 , doctest >= 0.11.4

100+ , squeal-postgresql

73101

74−test-suite squeal-postgresql-specs

102+test-suite properties

75103 default-language: Haskell2010

76104 type: exitcode-stdio-1.0

77− hs-source-dirs: test/Specs

78− ghc-options: -Wall -main-is Specs

79− main-is: Specs.hs

80− other-modules: ExceptionHandling

105+ hs-source-dirs: test

106+ ghc-options: -Wall

107+ main-is: Property.hs

81108 build-depends:

82109 base >= 4.10.0.0

83110 , 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

84127 , generics-sop >= 0.3.1.0

85128 , hspec >= 2.4.8

129+ , mtl >= 2.2.2

86130 , squeal-postgresql

87131 , text >= 1.2.2.2

88− , transformers >= 0.5.2.0

89− , transformers-base >= 0.4.4

90132 , vector >= 0.12.0.1

91133

92−executable squeal-postgresql-example

134+executable example

93135 default-language: Haskell2010

94136 hs-source-dirs: exe

95137 ghc-options: -Wall

@@ -102,5 +144,4 @@ executable squeal-postgresql-example

102144 , squeal-postgresql

103145 , text >= 1.2.2.2

104146 , transformers >= 0.5.2.0

105− , transformers-base >= 0.4.4

106147 , 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+446−153

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

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

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

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

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

1212to encode Haskell values into statement parameters.

1313

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

15+

1416>>> import Data.Int (Int16)

1517>>> import Data.Text (Text)

18+>>> import Control.Monad (void)

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

20+>>> import Squeal.PostgreSQL

21+

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

23+round trip query.

1624

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

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

1826>>> instance Generic Row

1927>>> instance HasDatatypeInfo Row

28+>>> :{

29+let

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

31+ roundTrip = values_ $

32+ parameter @1 int2 `as` #col1 :*

33+ parameter @2 text `as` #col2 :*

34+ parameter @3 bool `as` #col3

35+:}

2036

21−>>> import Control.Monad (void)

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

23−>>> import Squeal.PostgreSQL

37+So long as we can encode the parameters and then decode the result of the query,

38+the input and output should be equal.

2439

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

2541>>> :{

26−let

27− query :: Query '[]

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

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

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

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

43+ result <- runQueryParams roundTrip input

44+ Just output <- firstRow result

45+ liftIO . print $ input == output

46+:}

47+True

48+

49+In addition to being able to encode and decode basic Haskell types

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

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

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

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

54+create multi-dimensional fixed length arrays.

55+

56+>>> :{

57+data Row = Row

58+ { col1 :: VarArray (Vector Int16)

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

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

61+ } deriving (Eq, GHC.Generic)

3162:}

3263

64+>>> instance Generic Row

65+>>> instance HasDatatypeInfo Row

66+

67+Once again, we define a simple round trip query.

68+

3369>>> :{

3470let

35− roundtrip :: IO ()

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

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

38− Just row <- firstRow result

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

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

72+ roundTrip = values_ $

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

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

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

4076:}

4177

42−>>> roundtrip

78+>>> :set -XOverloadedLists

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

80+>>> :{

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

82+ result <- runQueryParams roundTrip input

83+ Just output <- firstRow result

84+ liftIO . print $ input == output

85+:}

4386True

4487

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

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

47−Postgres enumerated and composite types.

48−

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

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

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

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

5392

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

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

5594>>> instance Generic Schwarma

5695>>> instance HasDatatypeInfo Schwarma

5796

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

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

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

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

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

6299

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

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

64101>>> instance Generic Person

65102>>> instance HasDatatypeInfo Person

103+>>> instance Aeson.FromJSON Person

104+>>> instance Aeson.ToJSON Person

66105

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

68107

69108>>> :{

70109type Schema =

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

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

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

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

73112 ]

74113:}

75114

76115>>> :{

77116let

78− setup :: Definition '[] Schema

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

79118 setup =

80119 createTypeEnumFrom @Schwarma #schwarma >>>

81120 createTypeCompositeFrom @Person #person

82121:}

83122

84−Then we can perform roundtrip queries;

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

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

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

85126

127+>>> :{

128+data Row = Row

129+ { schwarma :: Enumerated Schwarma

130+ , person1 :: Composite Person

131+ , person2 :: Json Person

132+ } deriving (Eq, GHC.Generic)

133+:}

134+

135+>>> instance Generic Row

136+>>> instance HasDatatypeInfo Row

86137>>> :{

87138let

88− querySchwarma :: Query Schema

89− '[ 'NotNull (EnumFrom Schwarma)]

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

91− querySchwarma = values_ (parameter @1 #schwarma `as` #fromOnly)

139+ input = Row

140+ (Enumerated Chicken)

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

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

92143:}

93144

145+Once again, define a round trip query.

146+

94147>>> :{

95148let

96− queryPerson :: Query Schema

97− '[ 'NotNull (CompositeFrom Person)]

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

99− queryPerson = values_ (parameter @1 #person `as` #fromOnly)

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

150+ roundTrip = values_ $

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

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

153+ parameter @3 json `as` #person2

100154:}

101155

102−And finally drop the types.

156+Finally, we can drop our type definitions.

103157

104158>>> :{

105159let

106− teardown :: Definition Schema '[]

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

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

108162:}

109163

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

112166>>> :{

113167let

114168 session = do

115− result1 <- runQueryParams querySchwarma (Only Chicken)

116− Just (Only schwarma) <- firstRow result1

117− liftBase $ print (schwarma :: Schwarma)

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

119− Just (Only person) <- firstRow result2

120− liftBase $ print (person :: Person)

169+ result <- runQueryParams roundTrip input

170+ Just output <- firstRow result

171+ liftIO . print $ input == output

121172in

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

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

123174 define setup

124175 & pqThen session

125176 & pqThen (define teardown)

126177:}

127−Chicken

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

178+True

129179-}

130180

131181{-# LANGUAGE

@@ -134,56 +184,76 @@ Person {name = Just "Faisal", age = Just 24}

134184 , DeriveFunctor

135185 , DeriveGeneric

136186 , DeriveTraversable

187+ , DefaultSignatures

137188 , FlexibleContexts

138189 , FlexibleInstances

190+ , FunctionalDependencies

139191 , GADTs

140192 , LambdaCase

141193 , OverloadedStrings

142194 , MultiParamTypeClasses

143195 , ScopedTypeVariables

144196 , TypeApplications

197+ , TypeFamilies

145198 , TypeInType

146199 , TypeOperators

147200 , UndecidableInstances

201+ , UndecidableSuperClasses

148202#-}

149203

150204module Squeal.PostgreSQL.Binary

151205 ( -- * Encoding

152206 ToParam (..)

153207 , ToParams (..)

208+ , ToNullityParam (..)

209+ , ToField (..)

210+ , ToFixArray (..)

154211 -- * Decoding

155212 , FromValue (..)

156213 , FromRow (..)

214+ , FromField (..)

215+ , FromFixArray (..)

157216 -- * Only

158217 , Only (..)

218+ -- * Oid

219+ , OidOf (..)

220+ , OidOfParam (..)

221+ , OidOfField (..)

159222 ) where

160223

161224import BinaryParser

162−import ByteString.StrictBuilder

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

226+import Control.Arrow (left)

163227import Control.Monad

164−import Data.Aeson hiding (Null)

165228import Data.Int

166229import Data.Kind

167−import Data.Monoid hiding (All)

168230import Data.Scientific

169231import Data.Time

170232import Data.UUID.Types

171233import Data.Vector (Vector)

172234import Data.Word

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

173236import Generics.SOP

174237import Generics.SOP.Record

175238import GHC.TypeLits

176239import Network.IP.Addr

177240

178−import qualified Data.ByteString.Lazy as Lazy

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

180−import qualified Data.Text.Lazy as Lazy

181−import qualified Data.Text as Strict hiding (empty)

241+import qualified Data.Aeson as Aeson

242+import qualified Data.ByteString.Lazy as Lazy (ByteString)

243+import qualified Data.ByteString.Lazy as Lazy.ByteString

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

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

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

247+import qualified Data.Text as Strict.Text

182248import qualified Data.Vector as Vector

249+import qualified Database.PostgreSQL.LibPQ as LibPQ

183250import qualified GHC.Generics as GHC

184251import qualified PostgreSQL.Binary.Decoding as Decoding

185252import qualified PostgreSQL.Binary.Encoding as Encoding

186253

254+import Squeal.PostgreSQL.Alias

255+import Squeal.PostgreSQL.List

256+import Squeal.PostgreSQL.PG

187257import Squeal.PostgreSQL.Schema

188258

189259-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into

@@ -207,19 +277,20 @@ class ToParam (x :: Type) (pg :: PGType) where

207277 toParam :: x -> K Encoding.Encoding pg

208278instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

209279instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

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

211280instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

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

213281instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

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

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

215283instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

216284instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

217285instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric

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

218287instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

219288instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

220289instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

221290instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict

222291instance ToParam Lazy.Text 'PGtext where toParam = K . Encoding.text_lazy

292+instance ToParam String 'PGtext where

293+ toParam = K . Encoding.text_strict . Strict.Text.pack

223294instance ToParam Strict.ByteString 'PGbytea where

224295 toParam = K . Encoding.bytea_strict

225296instance ToParam Lazy.ByteString 'PGbytea where

@@ -233,43 +304,40 @@ instance ToParam LocalTime 'PGtimestamp where

233304instance ToParam UTCTime 'PGtimestamptz where

234305 toParam = K . Encoding.timestamptz_int

235306instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int

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

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

238−instance (HasOid pg, ToParam x pg)

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

240− toParam = K . Encoding.nullableArray_vector

241− (oid @pg) (unK . toParam @x @pg)

242−instance (HasOid pg, ToParam x pg)

243− => ToParam (Vector x) ('PGvararray ('NotNull pg)) where

244− toParam = K . Encoding.array_vector

245− (oid @pg) (unK . toParam @x @pg)

246−toVector :: (All ((~) x) xs) => NP I xs -> Vector x

247−toVector = \case

248− Nil -> Vector.empty

249− I x :* xs -> Vector.singleton x <> toVector xs

250−instance

251− ( HasOid pg

252− , ToParam x pg

253− , IsProductType hask xs

254− , All ((~) x) xs

255− , len ~ Length xs

256− ) => ToParam hask ('PGfixarray len ('NotNull pg)) where

257− toParam = K . Encoding.array_vector

258− (oid @pg) (unK . toParam @x @pg) . toVector . unZ . unSOP . from

259−instance

260− ( HasOid pg

261− , ToParam x pg

262− , IsProductType hask xs

263− , All ((~) (Maybe x)) xs

264− , len ~ Length xs

265− ) => ToParam hask ('PGfixarray len ('Null pg)) where

266− toParam = K . Encoding.nullableArray_vector

267− (oid @pg) (unK . toParam @x @pg) . toVector . unZ . unSOP . from

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

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

309+instance Aeson.ToJSON x => ToParam (Json x) 'PGjson where

310+ toParam = K . Encoding.json_bytes

311+ . Lazy.ByteString.toStrict . Aeson.encode . getJson

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

313+ toParam = K . Encoding.jsonb_bytes

314+ . Lazy.ByteString.toStrict . Aeson.encode . getJsonb

315+instance (ToNullityParam x ty, ty ~ nullity pg, OidOf pg)

316+ => ToParam (VarArray [x]) ('PGvararray ty) where

317+ toParam = K

318+ . Encoding.array_foldable

319+ (getOid (oidOf @pg)) (unK . toNullityParam @x @ty)

320+ . getVarArray

321+instance (ToParam x pg, OidOf pg)

322+ => ToParam (VarArray (Vector x)) ('PGvararray ('NotNull pg)) where

323+ toParam = K

324+ . Encoding.array_vector (getOid (oidOf @pg)) (unK . toParam @x @pg)

325+ . getVarArray

326+instance (ToParam x pg, OidOf pg)

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

328+ toParam = K

329+ . Encoding.nullableArray_vector

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

331+ . getVarArray

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

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

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

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

268336instance

269337 ( IsEnumType x

270338 , HasDatatypeInfo x

271− , LabelsFrom x ~ labels

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

339+ , LabelsPG x ~ labels

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

273341 toParam =

274342 let

275343 gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String

@@ -280,22 +348,23 @@ instance

280348 gshowConstructor constructors (SOP xs)

281349 in

282350 K . Encoding.text_strict

283− . Strict.pack

351+ . Strict.Text.pack

284352 . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))

285353 . from

354+ . getEnumerated

286355instance

287356 ( SListI fields

288357 , IsRecord x xs

289358 , AllZip ToField xs fields

290− , All HasAliasedOid fields

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

359+ , All OidOfField fields

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

292361 toParam =

293362 let

294363

295364 encoders = htrans (Proxy @ToField) toField

296365

297366 composite

298− :: All HasAliasedOid row

367+ :: All OidOfField row

299368 => NP (K (Maybe Encoding.Encoding)) row

300369 -> K Encoding.Encoding ('PGcomposite row)

301370 composite fields = K $

@@ -312,27 +381,142 @@ instance

312381 int32BE (fromIntegral (lengthSList (Proxy @xs))) <>

313382 let

314383 each

315− :: HasAliasedOid field

384+ :: OidOfField field

316385 => K (Maybe Encoding.Encoding) field

317386 -> Encoding.Encoding

318387 each (K field :: K (Maybe Encoding.Encoding) field) =

319− word32BE (aliasedOid @field)

388+ word32BE (getOid (oidOfField @field))

320389 <> case field of

321390 Nothing -> int64BE (-1)

322391 Just value ->

323392 int32BE (fromIntegral (builderLength value))

324393 <> value

325394 in

326− hcfoldMap (Proxy @HasAliasedOid) each fields

395+ hcfoldMap (Proxy @OidOfField) each fields

327396

328397 in

329− composite . encoders . toRecord

330−

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

332− aliasedOid :: Word32

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

334− aliasedOid = oid @ty

398+ composite . encoders . toRecord . getComposite

335399

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`.

336520class ToNullityParam (x :: Type) (ty :: NullityType) where

337521 toNullityParam :: x -> K (Maybe Encoding.Encoding) ty

338522instance ToParam x pg => ToNullityParam x ('NotNull pg) where

@@ -340,14 +524,36 @@ instance ToParam x pg => ToNullityParam x ('NotNull pg) where

340524instance ToParam x pg => ToNullityParam (Maybe x) ('Null pg) where

341525 toNullityParam = K . fmap (unK . toParam @x @pg)

342526

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.

343531class ToField (x :: (Symbol, Type)) (field :: (Symbol, NullityType)) where

344532 toField :: P x -> K (Maybe Encoding.Encoding) field

345533instance ToNullityParam x ty => ToField (alias ::: x) (alias ::: ty) where

346534 toField (P x) = K . unK $ toNullityParam @x @ty x

347535

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

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

538+-- You should not define instances for

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

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

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

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

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

544+ . toNullityParam @x @ty

545+instance

546+ ( IsProductType product xs

547+ , Length xs ~ dim

548+ , All ((~) x) xs

549+ , ToFixArray x dims ty )

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

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

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

553+

348554-- | A `ToParams` constraint generically sequences the encodings of `Type`s

349555-- of the fields of a tuple or record to a row of `ColumnType`s. You should

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

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

351557-- which in turn provide `ToParams` instances.

352558class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

353559 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]

@@ -376,14 +582,18 @@ instance FromValue 'PGbool Bool where fromValue = Decoding.bool

376582instance FromValue 'PGint2 Int16 where fromValue = Decoding.int

377583instance FromValue 'PGint4 Int32 where fromValue = Decoding.int

378584instance FromValue 'PGint8 Int64 where fromValue = Decoding.int

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

379586instance FromValue 'PGfloat4 Float where fromValue = Decoding.float4

380587instance FromValue 'PGfloat8 Double where fromValue = Decoding.float8

381588instance FromValue 'PGnumeric Scientific where fromValue = Decoding.numeric

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

382590instance FromValue 'PGuuid UUID where fromValue = Decoding.uuid

383591instance FromValue 'PGinet (NetAddr IP) where fromValue = Decoding.inet

384592instance FromValue ('PGchar 1) Char where fromValue = Decoding.char

385593instance FromValue 'PGtext Strict.Text where fromValue = Decoding.text_strict

386594instance FromValue 'PGtext Lazy.Text where fromValue = Decoding.text_lazy

595+instance FromValue 'PGtext String where

596+ fromValue = Strict.Text.unpack <$> Decoding.text_strict

387597instance FromValue 'PGbytea Strict.ByteString where

388598 fromValue = Decoding.bytea_strict

389599instance FromValue 'PGbytea Lazy.ByteString where

@@ -398,56 +608,54 @@ instance FromValue 'PGtimestamptz UTCTime where

398608 fromValue = Decoding.timestamptz_int

399609instance FromValue 'PGinterval DiffTime where

400610 fromValue = Decoding.interval_int

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

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

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

612+instance FromValue 'PGjsonb Aeson.Value where fromValue = Decoding.jsonb_ast

613+instance Aeson.FromJSON x => FromValue 'PGjson (Json x) where

614+ fromValue = Json <$>

615+ Decoding.json_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)

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

617+ fromValue = Jsonb <$>

618+ Decoding.jsonb_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)

403619instance FromValue pg y

404− => FromValue ('PGvararray ('Null pg)) (Vector (Maybe y)) where

405− fromValue = Decoding.array

406− (Decoding.dimensionArray Vector.replicateM

407− (Decoding.nullableValueArray (fromValue @pg)))

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))

408627instance FromValue pg y

409− => FromValue ('PGvararray ('NotNull pg)) (Vector y) where

410− fromValue = Decoding.array

411− (Decoding.dimensionArray Vector.replicateM

412− (Decoding.valueArray (fromValue @pg)))

413−fromVector

414− :: forall x xs. (All ((~) x) xs, SListI xs)

415− => Vector x

416− -> Decoding.Value (NP I xs)

417−fromVector vec = case fromList (Vector.toList vec) of

418− Nothing -> failure "fromVector: unexpected length"

419− Just xs -> return $ hcmap (Proxy :: Proxy ((~) x)) (I . unK) xs

420−instance

421− ( IsProductType hask ys

422− , All ((~) y) ys

423− , len ~ Length ys

424− , FromValue pg y

425− ) => FromValue ('PGfixarray len ('NotNull pg)) hask where

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

426629 fromValue =

427630 let

428− vectorValue = Decoding.array

429− (Decoding.dimensionArray Vector.replicateM

430− (Decoding.valueArray (fromValue @pg)))

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

431632 in

432− fmap (to . SOP . Z) (fromVector @y =<< vectorValue)

433−instance

434− ( IsProductType hask ys

435− , All ((~) (Maybe y)) ys

436− , len ~ Length ys

437− , FromValue pg y

438− ) => FromValue ('PGfixarray len ('Null pg)) hask where

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

439645 fromValue =

440646 let

441− vectorValue = Decoding.array

442− (Decoding.dimensionArray Vector.replicateM

443− (Decoding.nullableValueArray (fromValue @pg)))

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

444648 in

445− fmap (to . SOP . Z) (fromVector @(Maybe y) =<< vectorValue)

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)

446654instance

447655 ( IsEnumType y

448656 , HasDatatypeInfo y

449− , LabelsFrom y ~ labels

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

657+ , LabelsPG y ~ labels

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

451659 fromValue =

452660 let

453661 greadConstructor

@@ -461,14 +669,14 @@ instance

461669 then Just (SOP (Z Nil))

462670 else SOP . S . unSOP <$> greadConstructor constructors name

463671 in

464− Decoding.enum

672+ fmap Enumerated

673+ . Decoding.enum

465674 $ fmap to

466675 . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))

467− . Strict.unpack

468−

676+ . Strict.Text.unpack

469677instance

470678 ( FromRow fields y

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

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

472680 fromValue =

473681 let

474682 -- <number of fields: 4 bytes>

@@ -490,7 +698,7 @@ instance

490698 then return (K Nothing)

491699 else K . Just <$> bytesOfSize len

492700 in

493− Decoding.fn (fromRow @fields <=< composite)

701+ fmap Composite (Decoding.fn (fromRow @fields <=< composite))

494702

495703-- | A `FromField` constraint lifts the `FromValue` parser

496704-- to a decoding of a @(Symbol, NullityType)@ to a `Type`,

@@ -513,12 +721,34 @@ instance FromValue pg y

513721 K (Just bytestring) -> P . Just <$>

514722 Decoding.valueParser (fromValue @pg) bytestring

515723

724+-- | A `FromFixArray` constraint gives a decoding to a Haskell `Type`

725+-- from the binary format of a PostgreSQL fixed-length array.

726+-- You should not define instances for

727+-- `FromFixArray`, just use the provided instances.

728+class FromFixArray (dims :: [Nat]) (ty :: NullityType) (y :: Type) where

729+ fromFixArray :: Decoding.Array y

730+instance FromValue pg y => FromFixArray '[] ('NotNull pg) y where

731+ fromFixArray = Decoding.valueArray (fromValue @pg @y)

732+instance FromValue pg y => FromFixArray '[] ('Null pg) (Maybe y) where

733+ fromFixArray = Decoding.nullableValueArray (fromValue @pg @y)

734+instance

735+ ( IsProductType product ys

736+ , Length ys ~ dim

737+ , All ((~) y) ys

738+ , FromFixArray dims ty y )

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

740+ fromFixArray =

741+ let

742+ rep _ = fmap (to . SOP . Z) . replicateMN

743+ in

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

745+

516746-- | A `FromRow` constraint generically sequences the parsings of the columns

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

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

518748-- the same field names. You should not define instances of `FromRow`.

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

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

520750-- provide `FromRow` instances.

521−class SListI result => FromRow (result :: RelationType) y where

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

522752 -- | >>> :set -XOverloadedStrings

523753 -- >>> import Data.Text

524754 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show

@@ -539,6 +769,53 @@ instance

539769 = fmap fromRecord

540770 . hsequence'

541771 . 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)

542819

543820-- | `Only` is a 1-tuple type, useful for encoding a single parameter with

544821-- `toParams` or decoding a single value with `fromRow`.

@@ -553,3 +830,19 @@ newtype Only x = Only { fromOnly :: x }

553830 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)

554831instance Generic (Only x)

555832instance HasDatatypeInfo (Only x)

833+

834+foldlN

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

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

837+foldlN f z = \case

838+ Nil -> z

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

840+

841+replicateMN

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

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

844+replicateMN mx = hsequence' $

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

846+

847+getOid :: LibPQ.Oid -> Word32

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

squeal-postgresql/src/Squeal/PostgreSQL/Definition.hs+23−925

@@ -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 (TableToRelation 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 (TableToRelation 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 '[] relation

811− -- ^ query

812− -> Definition schema (Create view ('View relation) 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 (LabelsFrom hask)

861− , KnownSymbol enum

862− )

863− => Alias enum

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

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

866−createTypeEnumFrom enum = createTypeEnum enum

867− (SOP.hpure label :: NP PGlabel (LabelsFrom 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` field) =

900− renderAlias field <+> 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) (PGFieldsFrom hask)

912− , KnownSymbol ty )

913− => Alias ty

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

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

916−createTypeCompositeFrom ty = createTypeComposite ty

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

918− :: NP (Aliased (TypeExpression schema)) (PGFieldsFrom 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 (EnumFrom 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+340−1579

@@ -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

@@ -31,521 +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− , row

49− -- ** Functions

50− , unsafeBinaryOp

51− , unsafeUnaryOp

35+ Expression (..)

36+ , Expr

37+ , type (-->)

38+ , FunctionDB

5239 , unsafeFunction

53− , unsafeVariadicFunction

54− , atan2_

55− , cast

56− , quot_

57− , rem_

58− , trunc

59− , round_

60− , ceiling_

61− , greatest

62− , least

63− -- ** Conditions

64− , Condition

65− , true

66− , false

67− , not_

68− , (.&&)

69− , (.||)

70− , caseWhenThenElse

71− , ifThenElse

72− , (.==)

73− , (./=)

74− , (.>=)

75− , (.<)

76− , (.<=)

77− , (.>)

78− -- ** Time

79− , currentDate

80− , currentTime

81− , currentTimestamp

82− , localTime

83− , localTimestamp

84− -- ** Text

85− , lower

86− , upper

87− , charLength

88− , like

89− -- ** json or jsonb operators

90− , PGarray

91− , PGarrayOf

92− , PGjsonKey

93− , PGjson_

94− , (.->)

95− , (.->>)

96− , (.#>)

97− , (.#>>)

98− -- *** jsonb only operators

99− , (.@>)

100− , (.<@)

101− , (.?)

102− , (.?|)

103− , (.?&)

104− , (.-.)

105− , (#-.)

106− -- *** Functions

107− , jsonLit

108− , jsonbLit

109− , toJson

110− , toJsonb

111− , arrayToJson

112− , rowToJson

113− , jsonBuildArray

114− , jsonbBuildArray

115− , jsonBuildObject

116− , jsonbBuildObject

117− , jsonObject

118− , jsonbObject

119− , jsonZipObject

120− , jsonbZipObject

121− , jsonArrayLength

122− , jsonbArrayLength

123− , jsonExtractPath

124− , jsonbExtractPath

125− , jsonExtractPathAsText

126− , jsonbExtractPathAsText

127− , jsonObjectKeys

128− , jsonbObjectKeys

129− , jsonTypeof

130− , jsonbTypeof

131− , jsonStripNulls

132− , jsonbStripNulls

133− , jsonbSet

134− , jsonbInsert

135− , jsonbPretty

136− -- ** Aggregation

137− , unsafeAggregate, unsafeAggregateDistinct

138− , sum_, sumDistinct

139− , PGAvg (avg, avgDistinct)

140− , bitAnd, bitOr, boolAnd, boolOr

141− , bitAndDistinct, bitOrDistinct, boolAndDistinct, boolOrDistinct

142− , countStar

143− , count, countDistinct

144− , every, everyDistinct

145− , max_, maxDistinct, min_, minDistinct

146− -- * Types

147− , TypeExpression (UnsafeTypeExpression, renderTypeExpression)

148− , PGTyped (pgtype)

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 Generics.SOP hiding (from)

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

19570import GHC.OverloadedLabels

19671import GHC.TypeLits

72+import Numeric

19773import Prelude hiding (id, (.))

19874

19975import qualified GHC.Generics as GHC

20076

77+import Squeal.PostgreSQL.Alias

78+import Squeal.PostgreSQL.List

20179import Squeal.PostgreSQL.Render

20280import Squeal.PostgreSQL.Schema

20381

82+-- $setup

83+-- >>> import Squeal.PostgreSQL

84+

20485{-----------------------------------------

20586column expressions

20687-----------------------------------------}

20788

20889{- | `Expression`s are used in a variety of contexts,

209−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,

21092as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or

21193`Squeal.PostgreSQL.Manipulation.update`,

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

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

21395

21496The expression syntax allows the calculation of

21597values from primitive expression using arithmetic, logical,

21698and 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`.

217113-}

218114newtype Expression

219− (schema :: SchemaType)

220− (relations :: RelationsType)

221− (grouping :: Grouping)

115+ (outer :: FromType)

116+ (commons :: FromType)

117+ (grp :: Grouping)

118+ (schemas :: SchemasType)

222119 (params :: [NullityType])

120+ (from :: FromType)

223121 (ty :: NullityType)

224122 = UnsafeExpression { renderExpression :: ByteString }

225123 deriving (GHC.Generic,Show,Eq,Ord,NFData)

226−

227−instance RenderSQL (Expression schema relations grouping params ty) where

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

228125 renderSQL = renderExpression

229126

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

231−supplied externally to a SQL statement.

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

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

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

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

236−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)

237181-}

238−class KnownNat n => HasParameter

239− (n :: Nat)

240− (schema :: SchemaType)

241− (params :: [NullityType])

242− (ty :: NullityType)

243− | n params -> ty where

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

245− --

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

247− -- >>> printSQL expr

248− -- ($1 :: int4)

249− parameter

250− :: TypeExpression schema ty

251− -> Expression schema relations grouping params ty

252− parameter ty = UnsafeExpression $ parenthesized $

253− "$" <> renderNat @n <+> "::"

254− <+> renderTypeExpression ty

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

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

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

258−

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

260−-- infers a `TypeExpression`.

261−--

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

263−-- >>> printSQL expr

264−-- ($1 :: int4)

265−param

266− :: forall n schema params relations grouping ty

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

268− => Expression schema relations grouping params ty -- ^ param

269−param = parameter @n pgtype

270−

271−instance (HasUnique relation relations columns, Has column columns ty)

272− => IsLabel column (Expression schema relations 'Ungrouped params ty) where

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

274−instance (HasUnique relation relations columns, Has column columns ty)

275− => IsLabel column

276− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where

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

278−instance (HasUnique relation relations columns, Has column columns ty)

279− => IsLabel column

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

281− fromLabel = fromLabel @column :* Nil

282−

283−instance (Has relation relations columns, Has column columns ty)

284− => IsQualified relation column (Expression schema relations 'Ungrouped params ty) where

285− relation ! column = UnsafeExpression $

286− renderAlias relation <> "." <> renderAlias column

287−instance (Has relation relations columns, Has column columns ty)

288− => IsQualified relation column

289− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where

290− relation ! column = relation ! column `As` column

291−instance (Has relation relations columns, Has column columns ty)

292− => IsQualified relation column

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

294− relation ! column = relation ! column :* Nil

182+type (--->) xs y

183+ = forall outer commons grp schemas params from

184+ . NP (Expression outer commons grp schemas params from) xs

185+ -- ^ inputs

186+ -> Expression outer commons grp schemas params from y

187+ -- ^ output

188+

189+type FunctionNDB schemas xs y

190+ = forall outer commons grp params from

191+ . NP (Expression outer commons grp schemas params from) xs

192+ -- ^ inputs

193+ -> Expression outer commons grp schemas params from y

194+ -- ^ output

195+

196+{- | A @RankNType@ for functions with a variable-length list of

197+homogeneous arguments and at least 1 more argument.

198+-}

199+type FunctionVar x0 x1 y

200+ = forall outer commons grp schemas params from

201+ . [Expression outer commons grp schemas params from x0]

202+ -- ^ inputs

203+ -> Expression outer commons grp schemas params from x1

204+ -- ^ must have at least 1 input

205+ -> Expression outer commons grp schemas params from y

206+ -- ^ output

207+

208+{- | >>> printSQL (unsafeFunctionVar "greatest" [true, null_] false)

209+greatest(TRUE, NULL, FALSE)

210+-}

211+unsafeFunctionVar :: ByteString -> FunctionVar x0 x1 y

212+unsafeFunctionVar fun xs x = UnsafeExpression $ fun <> parenthesized

213+ (commaSeparated (renderSQL <$> xs) <> ", " <> renderSQL x)

214+

215+instance (HasUnique tab (Join outer from) row, Has col row ty)

216+ => IsLabel col (Expression outer commons 'Ungrouped schemas params from ty) where

217+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)

218+instance (HasUnique tab (Join outer from) row, Has col row ty, tys ~ '[ty])

219+ => IsLabel col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where

220+ fromLabel = fromLabel @col :* Nil

221+instance (HasUnique tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))

222+ => IsLabel col

223+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where

224+ fromLabel = fromLabel @col `As` Alias

225+instance (HasUnique tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])

226+ => IsLabel col

227+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where

228+ fromLabel = fromLabel @col :* Nil

229+

230+instance (Has tab (Join outer from) row, Has col row ty)

231+ => IsQualified tab col (Expression outer commons 'Ungrouped schemas params from ty) where

232+ tab ! col = UnsafeExpression $

233+ renderSQL tab <> "." <> renderSQL col

234+instance (Has tab (Join outer from) row, Has col row ty, tys ~ '[ty])

235+ => IsQualified tab col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where

236+ tab ! col = tab ! col :* Nil

237+instance (Has tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))

238+ => IsQualified tab col

239+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where

240+ tab ! col = tab ! col `As` col

241+instance (Has tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])

242+ => IsQualified tab col

243+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where

244+ tab ! col = tab ! col :* Nil

295245

296246instance

297− ( HasUnique relation relations columns

298− , Has column columns ty

299− , GroupedBy relation column bys

300− ) => IsLabel column

301− (Expression schema relations ('Grouped bys) params ty) where

302− 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)

253+instance

254+ ( HasUnique tab (Join outer from) row

255+ , Has col row ty

256+ , GroupedBy tab col bys

257+ , tys ~ '[ty]

258+ ) => IsLabel col

259+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where

260+ fromLabel = fromLabel @col :* Nil

303261instance

304− ( HasUnique relation relations columns

305− , Has column columns ty

306− , GroupedBy relation column bys

307− ) => IsLabel column

308− ( Aliased (Expression schema relations ('Grouped bys) params)

309− (column ::: ty) ) where

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

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

311269instance

312− ( HasUnique relation relations columns

313− , Has column columns ty

314− , GroupedBy relation column bys

315− ) => IsLabel column

316− ( NP (Aliased (Expression schema relations ('Grouped bys) params))

317− '[column ::: ty] ) where

318− fromLabel = fromLabel @column :* Nil

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

319277

320278instance

321− ( Has relation relations columns

322− , Has column columns ty

323− , GroupedBy relation column bys

324− ) => IsQualified relation column

325− (Expression schema relations ('Grouped bys) params ty) where

326− relation ! column = UnsafeExpression $

327− renderAlias relation <> "." <> renderAlias column

279+ ( Has tab (Join outer from) row

280+ , Has col row ty

281+ , GroupedBy tab col bys

282+ ) => IsQualified tab col

283+ (Expression outer commons ('Grouped bys) schemas params from ty) where

284+ tab ! col = UnsafeExpression $

285+ renderSQL tab <> "." <> renderSQL col

328286instance

329− ( Has relation relations columns

330− , Has column columns ty

331− , GroupedBy relation column bys

332− ) => IsQualified relation column

333− (Aliased (Expression schema relations ('Grouped bys) params)

334− (column ::: ty)) where

335− relation ! column = relation ! column `As` column

287+ ( Has tab (Join outer from) row

288+ , Has col row ty

289+ , GroupedBy tab col bys

290+ , tys ~ '[ty]

291+ ) => IsQualified tab col

292+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where

293+ tab ! col = tab ! col :* Nil

336294instance

337− ( Has relation relations columns

338− , Has column columns ty

339− , GroupedBy relation column bys

340− ) => IsQualified relation column

341− ( NP (Aliased (Expression schema relations ('Grouped bys) params))

342− '[column ::: ty]) where

343− relation ! column = relation ! column :* Nil

344−

345−-- | analagous to `Nothing`

346−--

347−-- >>> printSQL null_

348−-- NULL

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

350−null_ = UnsafeExpression "NULL"

351−

352−-- | analagous to `Just`

353−--

354−-- >>> printSQL $ notNull true

355−-- TRUE

356−notNull

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

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

359−notNull = UnsafeExpression . renderExpression

360−

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

362−--

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

364−-- COALESCE(NULL, TRUE, FALSE)

365−coalesce

366− :: [Expression schema relations grouping params ('Null ty)]

367− -- ^ @NULL@s may be present

368− -> Expression schema relations grouping params ('NotNull ty)

369− -- ^ @NULL@ is absent

370− -> Expression schema relations grouping params ('NotNull ty)

371−coalesce nullxs notNullx = UnsafeExpression $

372− "COALESCE" <> parenthesized (commaSeparated

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

374−

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

376−--

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

378−-- COALESCE(NULL, TRUE)

379−fromNull

380− :: Expression schema relations grouping params ('NotNull ty)

381− -- ^ what to convert @NULL@ to

382− -> Expression schema relations grouping params ('Null ty)

383− -> Expression schema relations grouping params ('NotNull ty)

384−fromNull notNullx nullx = coalesce [nullx] notNullx

385−

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

387−-- NULL IS NULL

388−isNull

389− :: Expression schema relations grouping params ('Null ty)

390− -- ^ possibly @NULL@

391− -> Condition schema relations grouping params

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

393−

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

395−-- NULL IS NOT NULL

396−isNotNull

397− :: Expression schema relations grouping params ('Null ty)

398− -- ^ possibly @NULL@

399− -> Condition schema relations grouping params

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

401−

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

403−--

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

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

406−matchNull

407− :: Expression schema relations grouping params (nullty)

408− -- ^ what to convert @NULL@ to

409− -> ( Expression schema relations grouping params ('NotNull ty)

410− -> Expression schema relations grouping params (nullty) )

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

412− -> Expression schema relations grouping params ('Null ty)

413− -> Expression schema relations grouping params (nullty)

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

415− (f (UnsafeExpression (renderExpression x)))

416−

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

418−`nullIf` gives @NULL@.

419−

420−>>> :set -XTypeApplications -XDataKinds

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

422−>>> printSQL expr

423−NULL IF (FALSE, ($1 :: bool))

424−-}

425−nullIf

426− :: Expression schema relations grouping params ('NotNull ty)

427− -- ^ @NULL@ is absent

428− -> Expression schema relations grouping params ('NotNull ty)

429− -- ^ @NULL@ is absent

430− -> Expression schema relations grouping params ('Null ty)

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

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

433−

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

435−-- ARRAY[NULL, FALSE, TRUE]

436−array

437− :: [Expression schema relations grouping params ty]

438− -- ^ array elements

439− -> Expression schema relations grouping params (nullity ('PGvararray ty))

440−array xs = UnsafeExpression $

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

295+ ( Has tab (Join outer from) row

296+ , Has col row ty

297+ , GroupedBy tab col bys

298+ , column ~ (col ::: ty)

299+ ) => IsQualified tab col

300+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where

301+ tab ! col = tab ! col `As` col

302+instance

303+ ( Has tab (Join outer from) row

304+ , Has col row ty

305+ , GroupedBy tab col bys

306+ , columns ~ '[col ::: ty]

307+ ) => IsQualified tab col

308+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where

309+ tab ! col = tab ! col :* Nil

442310

443311instance (KnownSymbol label, label `In` labels) => IsPGlabel label

444− (Expression schema relations grouping params (nullity ('PGenum labels))) where

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

446−

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

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

449−--

450−-- >>> :{

451−-- type Complex = 'PGcomposite

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

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

454−-- :}

455−--

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

457−-- >>> printSQL i

458−-- ROW(0, 1)

459−row

460− :: SListI fields

461− => NP (Aliased (Expression schema relations grouping params)) fields

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

463− -> Expression schema relations grouping params (nullity ('PGcomposite fields))

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

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

466−

467−instance Has field fields ty => IsLabel field

468− ( Expression schema relation grouping params ('NotNull ('PGcomposite fields))

469− -> Expression schema relation grouping params ty ) where

470− fromLabel expr = UnsafeExpression $

471− parenthesized (renderExpression expr) <> "." <>

472− renderSymbol @field

473−

474−instance Semigroup

475− (Expression schema relations grouping params (nullity ('PGvararray ty))) where

476− (<>) = unsafeBinaryOp "||"

477−

478−instance Monoid

479− (Expression schema relations grouping params (nullity ('PGvararray ty))) where

480− mempty = array []

481− mappend = (<>)

482−

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

484−-- >>> printSQL expr

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

486−greatest

487− :: Expression schema relations grouping params (nullty)

488− -- ^ needs at least 1 argument

489− -> [Expression schema relations grouping params (nullty)]

490− -- ^ or more

491− -> Expression schema relations grouping params (nullty)

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

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

494−

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

496−-- LEAST(CURRENT_TIMESTAMP, NULL)

497−least

498− :: Expression schema relations grouping params (nullty)

499− -- ^ needs at least 1 argument

500− -> [Expression schema relations grouping params (nullty)]

501− -- ^ or more

502− -> Expression schema relations grouping params (nullty)

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

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

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

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

505314

506315-- | >>> printSQL $ unsafeBinaryOp "OR" true false

507316-- (TRUE OR FALSE)

508−unsafeBinaryOp

509− :: ByteString

510− -- ^ operator

511− -> Expression schema relations grouping params (ty0)

512− -> Expression schema relations grouping params (ty1)

513− -> Expression schema relations grouping params (ty2)

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

514318unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

515− 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

516327

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

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

518329-- (NOT TRUE)

519−unsafeUnaryOp

520− :: ByteString

521− -- ^ operator

522− -> Expression schema relations grouping params (ty0)

523− -> Expression schema relations grouping params (ty1)

524−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $

525− 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

526351

527352-- | >>> printSQL $ unsafeFunction "f" true

528353-- f(TRUE)

529−unsafeFunction

530− :: ByteString

531− -- ^ function

532− -> Expression schema relations grouping params (xty)

533− -> Expression schema relations grouping params (yty)

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

534355unsafeFunction fun x = UnsafeExpression $

535− fun <> parenthesized (renderExpression x)

536−

537−-- | Helper for defining variadic functions.

538−unsafeVariadicFunction

539− :: SListI elems

540− => ByteString

541− -- ^ function

542− -> NP (Expression schema relations grouping params) elems

543− -> Expression schema relations grouping params ret

544−unsafeVariadicFunction fun x = UnsafeExpression $

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

546−

547−instance PGNum ty

548− => Num (Expression schema relations grouping params (nullity ty)) where

356+ fun <> parenthesized (renderSQL x)

357+

358+function

359+ :: (Has sch schemas schema, Has fun schema ('Function ('[x] :=> 'Returns y)))

360+ => QualifiedAlias sch fun

361+ -> FunctionDB schemas x y

362+function = unsafeFunction . renderSQL

363+

364+-- | >>> printSQL $ unsafeFunctionN "f" (currentTime :* localTimestamp :* false *: literal 'a')

365+-- f(CURRENT_TIME, LOCALTIMESTAMP, FALSE, E'a')

366+unsafeFunctionN :: SListI xs => ByteString -> xs ---> y

367+unsafeFunctionN fun xs = UnsafeExpression $

368+ fun <> parenthesized (renderCommaSeparated renderSQL xs)

369+

370+functionN

371+ :: ( Has sch schemas schema

372+ , Has fun schema ('Function (xs :=> 'Returns y))

373+ , SListI xs )

374+ => QualifiedAlias sch fun

375+ -> FunctionNDB schemas xs y

376+functionN = unsafeFunctionN . renderSQL

377+

378+instance ty `In` PGNum

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

549380 (+) = unsafeBinaryOp "+"

550381 (-) = unsafeBinaryOp "-"

551382 (*) = unsafeBinaryOp "*"

@@ -556,19 +387,24 @@ instance PGNum ty

556387 . fromString

557388 . show

558389

559−instance (PGNum ty, PGFloating ty) => Fractional

560− (Expression schema relations grouping params (nullity ty)) where

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

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

561392 (/) = unsafeBinaryOp "/"

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

393+ fromRational

394+ = UnsafeExpression

395+ . fromString

396+ . ($ "")

397+ . showFFloat Nothing

398+ . fromRat @Double

563399

564−instance (PGNum ty, PGFloating ty) => Floating

565− (Expression schema relations grouping params (nullity ty)) where

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

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

566402 pi = UnsafeExpression "pi()"

567403 exp = unsafeFunction "exp"

568404 log = unsafeFunction "ln"

569405 sqrt = unsafeFunction "sqrt"

570406 b ** x = UnsafeExpression $

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

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

572408 logBase b y = log y / log b

573409 sin = unsafeFunction "sin"

574410 cos = unsafeFunction "cos"

@@ -583,1129 +419,54 @@ instance (PGNum ty, PGFloating ty) => Floating

583419 acosh x = log (x + sqrt (x*x - 1))

584420 atanh x = log ((1 + x) / (1 - x)) / 2

585421

586−-- | >>> :{

587−-- let

588−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

589−-- expression = atan2_ pi 2

590−-- in printSQL expression

591−-- :}

592−-- atan2(pi(), 2)

593−atan2_

594− :: PGFloating float

595− => Expression schema relations grouping params (nullity float)

596− -- ^ numerator

597− -> Expression schema relations grouping params (nullity float)

598− -- ^ denominator

599− -> Expression schema relations grouping params (nullity float)

600−atan2_ y x = UnsafeExpression $

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

602−

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

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

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

606−--

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

608−-- (TRUE :: int4)

609−cast

610− :: TypeExpression schema ty1

611− -- ^ type to cast as

612− -> Expression schema relations grouping params ty0

613− -- ^ value to convert

614− -> Expression schema relations grouping params ty1

615−cast ty x = UnsafeExpression $ parenthesized $

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

617−

618−-- | integer division, truncates the result

619−--

620−-- >>> :{

621−-- let

622−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

623−-- expression = 5 `quot_` 2

624−-- in printSQL expression

625−-- :}

626−-- (5 / 2)

627−quot_

628− :: PGIntegral int

629− => Expression schema relations grouping params (nullity int)

630− -- ^ numerator

631− -> Expression schema relations grouping params (nullity int)

632− -- ^ denominator

633− -> Expression schema relations grouping params (nullity int)

634−quot_ = unsafeBinaryOp "/"

635−

636−-- | remainder upon integer division

637−--

638−-- >>> :{

639−-- let

640−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

641−-- expression = 5 `rem_` 2

642−-- in printSQL expression

643−-- :}

644−-- (5 % 2)

645−rem_

646− :: PGIntegral int

647− => Expression schema relations grouping params (nullity int)

648− -- ^ numerator

649− -> Expression schema relations grouping params (nullity int)

650− -- ^ denominator

651− -> Expression schema relations grouping params (nullity int)

652−rem_ = unsafeBinaryOp "%"

653−

654−-- | >>> :{

655−-- let

656−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

657−-- expression = trunc pi

658−-- in printSQL expression

659−-- :}

660−-- trunc(pi())

661−trunc

662− :: PGFloating frac

663− => Expression schema relations grouping params (nullity frac)

664− -- ^ fractional number

665− -> Expression schema relations grouping params (nullity frac)

666−trunc = unsafeFunction "trunc"

667−

668−-- | >>> :{

669−-- let

670−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

671−-- expression = round_ pi

672−-- in printSQL expression

673−-- :}

674−-- round(pi())

675−round_

676− :: PGFloating frac

677− => Expression schema relations grouping params (nullity frac)

678− -- ^ fractional number

679− -> Expression schema relations grouping params (nullity frac)

680−round_ = unsafeFunction "round"

681−

682−-- | >>> :{

683−-- let

684−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

685−-- expression = ceiling_ pi

686−-- in printSQL expression

687−-- :}

688−-- ceiling(pi())

689−ceiling_

690− :: PGFloating frac

691− => Expression schema relations grouping params (nullity frac)

692− -- ^ fractional number

693− -> Expression schema relations grouping params (nullity frac)

694−ceiling_ = unsafeFunction "ceiling"

695−

696−-- | A `Condition` is a boolean valued `Expression`. While SQL allows

697−-- conditions to have @NULL@, Squeal instead chooses to disallow @NULL@,

698−-- forcing one to handle the case of @NULL@ explicitly to produce

699−-- a `Condition`.

700−type Condition schema relations grouping params =

701− Expression schema relations grouping params ('NotNull 'PGbool)

702−

703−-- | >>> printSQL true

704−-- TRUE

705−true :: Condition schema relations grouping params

706−true = UnsafeExpression "TRUE"

707−

708−-- | >>> printSQL false

709−-- FALSE

710−false :: Condition schema relations grouping params

711−false = UnsafeExpression "FALSE"

712−

713−-- | >>> printSQL $ not_ true

714−-- (NOT TRUE)

715−not_

716− :: Condition schema relations grouping params

717− -> Condition schema relations grouping params

718−not_ = unsafeUnaryOp "NOT"

719−

720−-- | >>> printSQL $ true .&& false

721−-- (TRUE AND FALSE)

722−(.&&)

723− :: Condition schema relations grouping params

724− -> Condition schema relations grouping params

725− -> Condition schema relations grouping params

726−(.&&) = unsafeBinaryOp "AND"

727−

728−-- | >>> printSQL $ true .|| false

729−-- (TRUE OR FALSE)

730−(.||)

731− :: Condition schema relations grouping params

732− -> Condition schema relations grouping params

733− -> Condition schema relations grouping params

734−(.||) = unsafeBinaryOp "OR"

735−

736−-- | >>> :{

737−-- let

738−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

739−-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3

740−-- in printSQL expression

741−-- :}

742−-- CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END

743−caseWhenThenElse

744− :: [ ( Condition schema relations grouping params

745− , Expression schema relations grouping params (ty)

746− ) ]

747− -- ^ whens and thens

748− -> Expression schema relations grouping params (ty)

749− -- ^ else

750− -> Expression schema relations grouping params (ty)

751−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat

752− [ "CASE"

753− , mconcat

754− [ mconcat

755− [ " WHEN ", renderExpression when_

756− , " THEN ", renderExpression then_

757− ]

758− | (when_,then_) <- whenThens

759− ]

760− , " ELSE ", renderExpression else_

761− , " END"

762− ]

763−

764−-- | >>> :{

765−-- let

766−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

767−-- expression = ifThenElse true 1 0

768−-- in printSQL expression

769−-- :}

770−-- CASE WHEN TRUE THEN 1 ELSE 0 END

771−ifThenElse

772− :: Condition schema relations grouping params

773− -> Expression schema relations grouping params (ty) -- ^ then

774− -> Expression schema relations grouping params (ty) -- ^ else

775− -> Expression schema relations grouping params (ty)

776−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_

777−

778−-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`

779−-- will produce @NULL@s if one of their arguments is @NULL@.

780−--

781−-- >>> printSQL $ notNull true .== null_

782−-- (TRUE = NULL)

783−(.==)

784− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

785− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

786− -> Expression schema relations grouping params (nullity 'PGbool)

787−(.==) = unsafeBinaryOp "="

788−infix 4 .==

789−

790−-- | >>> printSQL $ notNull true ./= null_

791−-- (TRUE <> NULL)

792−(./=)

793− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

794− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

795− -> Expression schema relations grouping params (nullity 'PGbool)

796−(./=) = unsafeBinaryOp "<>"

797−infix 4 ./=

798−

799−-- | >>> printSQL $ notNull true .>= null_

800−-- (TRUE >= NULL)

801−(.>=)

802− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

803− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

804− -> Expression schema relations grouping params (nullity 'PGbool)

805−(.>=) = unsafeBinaryOp ">="

806−infix 4 .>=

807−

808−-- | >>> printSQL $ notNull true .< null_

809−-- (TRUE < NULL)

810−(.<)

811− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

812− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

813− -> Expression schema relations grouping params (nullity 'PGbool)

814−(.<) = unsafeBinaryOp "<"

815−infix 4 .<

816−

817−-- | >>> printSQL $ notNull true .<= null_

818−-- (TRUE <= NULL)

819−(.<=)

820− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

821− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

822− -> Expression schema relations grouping params (nullity 'PGbool)

823−(.<=) = unsafeBinaryOp "<="

824−infix 4 .<=

825−

826−-- | >>> printSQL $ notNull true .> null_

827−-- (TRUE > NULL)

828−(.>)

829− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

830− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

831− -> Expression schema relations grouping params (nullity 'PGbool)

832−(.>) = unsafeBinaryOp ">"

833−infix 4 .>

834−

835−-- | >>> printSQL currentDate

836−-- CURRENT_DATE

837−currentDate

838− :: Expression schema relations grouping params (nullity 'PGdate)

839−currentDate = UnsafeExpression "CURRENT_DATE"

840−

841−-- | >>> printSQL currentTime

842−-- CURRENT_TIME

843−currentTime

844− :: Expression schema relations grouping params (nullity 'PGtimetz)

845−currentTime = UnsafeExpression "CURRENT_TIME"

846−

847−-- | >>> printSQL currentTimestamp

848−-- CURRENT_TIMESTAMP

849−currentTimestamp

850− :: Expression schema relations grouping params (nullity 'PGtimestamptz)

851−currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"

852−

853−-- | >>> printSQL localTime

854−-- LOCALTIME

855−localTime

856− :: Expression schema relations grouping params (nullity 'PGtime)

857−localTime = UnsafeExpression "LOCALTIME"

858−

859−-- | >>> printSQL localTimestamp

860−-- LOCALTIMESTAMP

861−localTimestamp

862− :: Expression schema relations grouping params (nullity 'PGtimestamp)

863−localTimestamp = UnsafeExpression "LOCALTIMESTAMP"

864−

865−{-----------------------------------------

866−text

867−-----------------------------------------}

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)

868438

869439instance IsString

870− (Expression schema relations grouping params (nullity 'PGtext)) where

440+ (Expression outer commons grp schemas params from (null 'PGtext)) where

871441 fromString str = UnsafeExpression $

872442 "E\'" <> fromString (escape =<< str) <> "\'"

873− where

874− escape = \case

875− '\NUL' -> "\\0"

876− '\'' -> "''"

877− '"' -> "\\\""

878− '\b' -> "\\b"

879− '\n' -> "\\n"

880− '\r' -> "\\r"

881− '\t' -> "\\t"

882− '\\' -> "\\\\"

883− 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) <> "\'"

884451

885452instance Semigroup

886− (Expression schema relations grouping params (nullity 'PGtext)) where

453+ (Expression outer commons grp schemas params from (null ('PGvararray ty))) where

454+ (<>) = unsafeBinaryOp "||"

455+instance Semigroup

456+ (Expression outer commons grp schemas params from (null 'PGjsonb)) where

457+ (<>) = unsafeBinaryOp "||"

458+instance Semigroup

459+ (Expression outer commons grp schemas params from (null 'PGtext)) where

460+ (<>) = unsafeBinaryOp "||"

461+instance Semigroup

462+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

887463 (<>) = unsafeBinaryOp "||"

888464

889465instance Monoid

890− (Expression schema relations grouping params (nullity 'PGtext)) where

466+ (Expression outer commons grp schemas params from (null 'PGtext)) where

467+ mempty = fromString ""

468+ mappend = (<>)

469+instance Monoid

470+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

891471 mempty = fromString ""

892472 mappend = (<>)

893−

894−-- | >>> printSQL $ lower "ARRRGGG"

895−-- lower(E'ARRRGGG')

896−lower

897− :: Expression schema relations grouping params (nullity 'PGtext)

898− -- ^ string to lower case

899− -> Expression schema relations grouping params (nullity 'PGtext)

900−lower = unsafeFunction "lower"

901−

902−-- | >>> printSQL $ upper "eeee"

903−-- upper(E'eeee')

904−upper

905− :: Expression schema relations grouping params (nullity 'PGtext)

906− -- ^ string to upper case

907− -> Expression schema relations grouping params (nullity 'PGtext)

908−upper = unsafeFunction "upper"

909−

910−-- | >>> printSQL $ charLength "four"

911−-- char_length(E'four')

912−charLength

913− :: Expression schema relations grouping params (nullity 'PGtext)

914− -- ^ string to measure

915− -> Expression schema relations grouping params (nullity 'PGint4)

916−charLength = unsafeFunction "char_length"

917−

918−-- | The `like` expression returns true if the @string@ matches

919−-- the supplied @pattern@. If @pattern@ does not contain percent signs

920−-- or underscores, then the pattern only represents the string itself;

921−-- in that case `like` acts like the equals operator. An underscore (_)

922−-- in pattern stands for (matches) any single character; a percent sign (%)

923−-- matches any sequence of zero or more characters.

924−--

925−-- >>> printSQL $ "abc" `like` "a%"

926−-- (E'abc' LIKE E'a%')

927−like

928− :: Expression schema relations grouping params (nullity 'PGtext)

929− -- ^ string

930− -> Expression schema relations grouping params (nullity 'PGtext)

931− -- ^ pattern

932− -> Expression schema relations grouping params (nullity 'PGbool)

933−like = unsafeBinaryOp "LIKE"

934−

935−{-----------------------------------------

936− -- json and jsonb support

937−

938−See https://www.postgresql.org/docs/10/static/functions-json.html -- most

939−comments lifted directly from this page.

940−

941−Table 9.44: json and jsonb operators

942−-----------------------------------------}

943−

944−-- | Get JSON value (object field or array element) at a key.

945−(.->)

946− :: (PGjson_ json, PGjsonKey key)

947− => Expression schema relations grouping params (nullity json)

948− -> Expression schema relations grouping params (nullity key)

949− -> Expression schema relations grouping params ('Null json)

950−(.->) = unsafeBinaryOp "->"

951−

952−-- | Get JSON value (object field or array element) at a key, as text.

953−(.->>)

954− :: (PGjson_ json, PGjsonKey key)

955− => Expression schema relations grouping params (nullity json)

956− -> Expression schema relations grouping params (nullity key)

957− -> Expression schema relations grouping params ('Null 'PGtext)

958−(.->>) = unsafeBinaryOp "->>"

959−

960−-- | Get JSON value at a specified path.

961−(.#>)

962− :: (PGjson_ json, PGtextArray "(.#>)" path)

963− => Expression schema relations grouping params (nullity json)

964− -> Expression schema relations grouping params (nullity path)

965− -> Expression schema relations grouping params ('Null json)

966−(.#>) = unsafeBinaryOp "#>"

967−

968−-- | Get JSON value at a specified path as text.

969−(.#>>)

970− :: (PGjson_ json, PGtextArray "(.#>>)" path)

971− => Expression schema relations grouping params (nullity json)

972− -> Expression schema relations grouping params (nullity path)

973− -> Expression schema relations grouping params ('Null 'PGtext)

974−(.#>>) = unsafeBinaryOp "#>>"

975−

976−-- Additional jsonb operators

977−

978−-- | Does the left JSON value contain the right JSON path/value entries at the

979−-- top level?

980−(.@>)

981− :: Expression schema relations grouping params (nullity 'PGjsonb)

982− -> Expression schema relations grouping params (nullity 'PGjsonb)

983− -> Condition schema relations grouping params

984−(.@>) = unsafeBinaryOp "@>"

985−

986−-- | Are the left JSON path/value entries contained at the top level within the

987−-- right JSON value?

988−(.<@)

989− :: Expression schema relations grouping params (nullity 'PGjsonb)

990− -> Expression schema relations grouping params (nullity 'PGjsonb)

991− -> Condition schema relations grouping params

992−(.<@) = unsafeBinaryOp "<@"

993−

994−-- | Does the string exist as a top-level key within the JSON value?

995−(.?)

996− :: Expression schema relations grouping params (nullity 'PGjsonb)

997− -> Expression schema relations grouping params (nullity 'PGtext)

998− -> Condition schema relations grouping params

999−(.?) = unsafeBinaryOp "?"

1000−

1001−-- | Do any of these array strings exist as top-level keys?

1002−(.?|)

1003− :: Expression schema relations grouping params (nullity 'PGjsonb)

1004− -> Expression schema relations grouping params (nullity ('PGvararray ('NotNull 'PGtext)))

1005− -> Condition schema relations grouping params

1006−(.?|) = unsafeBinaryOp "?|"

1007−

1008−-- | Do all of these array strings exist as top-level keys?

1009−(.?&)

1010− :: Expression schema relations grouping params (nullity 'PGjsonb)

1011− -> Expression schema relations grouping params (nullity ('PGvararray ('NotNull 'PGtext)))

1012− -> Condition schema relations grouping params

1013−(.?&) = unsafeBinaryOp "?&"

1014−

1015−-- | Concatenate two jsonb values into a new jsonb value.

1016−instance

1017− Semigroup (Expression schema relations grouping param (nullity 'PGjsonb)) where

1018− (<>) = unsafeBinaryOp "||"

1019−

1020−-- | Delete a key or keys from a JSON object, or remove an array element.

1021−--

1022−-- If the right operand is..

1023−--

1024−-- @ text @: Delete key/value pair or string element from left operand. Key/value pairs

1025−-- are matched based on their key value.

1026−--

1027−-- @ text[] @: Delete multiple key/value pairs or string elements

1028−-- from left operand. Key/value pairs are matched based on their key value.

1029−--

1030−-- @ integer @: Delete the array element with specified index (Negative integers

1031−-- count from the end). Throws an error if top level container is not an array.

1032−(.-.)

1033− :: (key `In` '[ 'PGtext, 'PGvararray ('NotNull 'PGtext), 'PGint4, 'PGint2 ]) -- hlint error without parens here

1034− => Expression schema relations grouping params (nullity 'PGjsonb)

1035− -> Expression schema relations grouping params (nullity key)

1036− -> Expression schema relations grouping params (nullity 'PGjsonb)

1037−(.-.) = unsafeBinaryOp "-"

1038−

1039−-- | Delete the field or element with specified path (for JSON arrays, negative

1040−-- integers count from the end)

1041−(#-.)

1042− :: PGtextArray "(#-.)" arrayty

1043− => Expression schema relations grouping params (nullity 'PGjsonb)

1044− -> Expression schema relations grouping params (nullity arrayty)

1045− -> Expression schema relations grouping params (nullity 'PGjsonb)

1046−(#-.) = unsafeBinaryOp "#-"

1047−

1048−{-----------------------------------------

1049−Table 9.45: JSON creation functions

1050−-----------------------------------------}

1051−

1052−-- | Literal binary JSON

1053−jsonbLit :: JSON.Value -> Expression schema relations grouping params (nullity 'PGjsonb)

1054−jsonbLit = cast jsonb . UnsafeExpression . singleQuotedUtf8 . toStrict . JSON.encode

1055−

1056−-- | Literal JSON

1057−jsonLit :: JSON.Value -> Expression schema relations grouping params (nullity 'PGjson)

1058−jsonLit = cast json . UnsafeExpression . singleQuotedUtf8 . toStrict . JSON.encode

1059−

1060−-- | Returns the value as json. Arrays and composites are converted

1061−-- (recursively) to arrays and objects; otherwise, if there is a cast from the

1062−-- type to json, the cast function will be used to perform the conversion;

1063−-- otherwise, a scalar value is produced. For any scalar type other than a

1064−-- number, a Boolean, or a null value, the text representation will be used, in

1065−-- such a fashion that it is a valid json value.

1066−toJson

1067− :: Expression schema relations grouping params (nullity ty)

1068− -> Expression schema relations grouping params (nullity 'PGjson)

1069−toJson = unsafeFunction "to_json"

1070−

1071−-- | Returns the value as jsonb. Arrays and composites are converted

1072−-- (recursively) to arrays and objects; otherwise, if there is a cast from the

1073−-- type to json, the cast function will be used to perform the conversion;

1074−-- otherwise, a scalar value is produced. For any scalar type other than a

1075−-- number, a Boolean, or a null value, the text representation will be used, in

1076−-- such a fashion that it is a valid jsonb value.

1077−toJsonb

1078− :: Expression schema relations grouping params (nullity ty)

1079− -> Expression schema relations grouping params (nullity 'PGjsonb)

1080−toJsonb = unsafeFunction "to_jsonb"

1081−

1082−-- | Returns the array as a JSON array. A PostgreSQL multidimensional array

1083−-- becomes a JSON array of arrays.

1084−arrayToJson

1085− :: PGarray "arrayToJson" arr

1086− => Expression schema relations grouping params (nullity arr)

1087− -> Expression schema relations grouping params (nullity 'PGjson)

1088−arrayToJson = unsafeFunction "array_to_json"

1089−

1090−-- | Returns the row as a JSON object.

1091−rowToJson

1092− :: Expression schema relations grouping params (nullity ('PGcomposite ty))

1093− -> Expression schema relations grouping params (nullity 'PGjson)

1094−rowToJson = unsafeFunction "row_to_json"

1095−

1096−-- | Builds a possibly-heterogeneously-typed JSON array out of a variadic

1097−-- argument list.

1098−jsonBuildArray

1099− :: SListI elems

1100− => NP (Expression schema relations grouping params) elems

1101− -> Expression schema relations grouping params (nullity 'PGjson)

1102−jsonBuildArray = unsafeVariadicFunction "json_build_array"

1103−

1104−-- | Builds a possibly-heterogeneously-typed (binary) JSON array out of a

1105−-- variadic argument list.

1106−jsonbBuildArray

1107− :: SListI elems

1108− => NP (Expression schema relations grouping params) elems

1109− -> Expression schema relations grouping params (nullity 'PGjsonb)

1110−jsonbBuildArray = unsafeVariadicFunction "jsonb_build_array"

1111−

1112−unsafeRowFunction

1113− :: All Top elems

1114− => NP (Aliased (Expression schema relations grouping params)) elems

1115− -> [ByteString]

1116−unsafeRowFunction =

1117− (`appEndo` []) . hcfoldMap (Proxy :: Proxy Top)

1118− (\(col `As` name) -> Endo $ \xs ->

1119− renderAliasString name : renderExpression col : xs)

1120−

1121−-- | Builds a possibly-heterogeneously-typed JSON object out of a variadic

1122−-- argument list. The elements of the argument list must alternate between text

1123−-- and values.

1124−jsonBuildObject

1125− :: All Top elems

1126− => NP (Aliased (Expression schema relations grouping params)) elems

1127− -> Expression schema relations grouping params (nullity 'PGjson)

1128−jsonBuildObject

1129− = unsafeFunction "json_build_object"

1130− . UnsafeExpression

1131− . commaSeparated

1132− . unsafeRowFunction

1133−

1134−-- | Builds a possibly-heterogeneously-typed (binary) JSON object out of a

1135−-- variadic argument list. The elements of the argument list must alternate

1136−-- between text and values.

1137−jsonbBuildObject

1138− :: All Top elems

1139− => NP (Aliased (Expression schema relations grouping params)) elems

1140− -> Expression schema relations grouping params (nullity 'PGjsonb)

1141−jsonbBuildObject

1142− = unsafeFunction "jsonb_build_object"

1143− . UnsafeExpression

1144− . commaSeparated

1145− . unsafeRowFunction

1146−

1147−-- | Builds a JSON object out of a text array. The array must have either

1148−-- exactly one dimension with an even number of members, in which case they are

1149−-- taken as alternating key/value pairs, or two dimensions such that each inner

1150−-- array has exactly two elements, which are taken as a key/value pair.

1151−jsonObject

1152− :: PGarrayOf "jsonObject" arr ('NotNull 'PGtext)

1153− => Expression schema relations grouping params (nullity arr)

1154− -> Expression schema relations grouping params (nullity 'PGjson)

1155−jsonObject = unsafeFunction "json_object"

1156−

1157−-- | Builds a binary JSON object out of a text array. The array must have either

1158−-- exactly one dimension with an even number of members, in which case they are

1159−-- taken as alternating key/value pairs, or two dimensions such that each inner

1160−-- array has exactly two elements, which are taken as a key/value pair.

1161−jsonbObject

1162− :: PGarrayOf "jsonbObject" arr ('NotNull 'PGtext)

1163− => Expression schema relations grouping params (nullity arr)

1164− -> Expression schema relations grouping params (nullity 'PGjsonb)

1165−jsonbObject = unsafeFunction "jsonb_object"

1166−

1167−-- | This is an alternate form of 'jsonObject' that takes two arrays; one for

1168−-- keys and one for values, that are zipped pairwise to create a JSON object.

1169−jsonZipObject

1170− :: ( PGarrayOf "jsonZipObject" keysArray ('NotNull 'PGtext)

1171− , PGarrayOf "jsonZipObject" valuesArray ('NotNull 'PGtext))

1172− => Expression schema relations grouping params (nullity keysArray)

1173− -> Expression schema relations grouping params (nullity valuesArray)

1174− -> Expression schema relations grouping params (nullity 'PGjson)

1175−jsonZipObject ks vs =

1176− unsafeVariadicFunction "json_object" (ks :* vs :* Nil)

1177−

1178−-- | This is an alternate form of 'jsonObject' that takes two arrays; one for

1179−-- keys and one for values, that are zipped pairwise to create a binary JSON

1180−-- object.

1181−jsonbZipObject

1182− :: ( PGarrayOf "jsonbZipObject" keysArray ('NotNull 'PGtext)

1183− , PGarrayOf "jsonbZipObject" valuesArray ('NotNull 'PGtext))

1184− => Expression schema relations grouping params (nullity keysArray)

1185− -> Expression schema relations grouping params (nullity valuesArray)

1186− -> Expression schema relations grouping params (nullity 'PGjsonb)

1187−jsonbZipObject ks vs =

1188− unsafeVariadicFunction "jsonb_object" (ks :* vs :* Nil)

1189−

1190−{-----------------------------------------

1191−Table 9.46: JSON processing functions

1192−-----------------------------------------}

1193−

1194−-- | Returns the number of elements in the outermost JSON array.

1195−jsonArrayLength

1196− :: Expression schema relations grouping params (nullity 'PGjson)

1197− -> Expression schema relations grouping params (nullity 'PGint4)

1198−jsonArrayLength = unsafeFunction "json_array_length"

1199−

1200−-- | Returns the number of elements in the outermost binary JSON array.

1201−jsonbArrayLength

1202− :: Expression schema relations grouping params (nullity 'PGjsonb)

1203− -> Expression schema relations grouping params (nullity 'PGint4)

1204−jsonbArrayLength = unsafeFunction "jsonb_array_length"

1205−

1206−-- | Returns JSON value pointed to by the given path (equivalent to #>

1207−-- operator).

1208−jsonExtractPath

1209− :: SListI elems

1210− => Expression schema relations grouping params (nullity 'PGjson)

1211− -> NP (Expression schema relations grouping params) elems

1212− -> Expression schema relations grouping params (nullity 'PGjsonb)

1213−jsonExtractPath x xs =

1214− unsafeVariadicFunction "json_extract_path" (x :* xs)

1215−

1216−-- | Returns JSON value pointed to by the given path (equivalent to #>

1217−-- operator).

1218−jsonbExtractPath

1219− :: SListI elems

1220− => Expression schema relations grouping params (nullity 'PGjsonb)

1221− -> NP (Expression schema relations grouping params) elems

1222− -> Expression schema relations grouping params (nullity 'PGjsonb)

1223−jsonbExtractPath x xs =

1224− unsafeVariadicFunction "jsonb_extract_path" (x :* xs)

1225−

1226−-- | Returns JSON value pointed to by the given path (equivalent to #>

1227−-- operator), as text.

1228−jsonExtractPathAsText

1229− :: SListI elems

1230− => Expression schema relations grouping params (nullity 'PGjson)

1231− -> NP (Expression schema relations grouping params) elems

1232− -> Expression schema relations grouping params (nullity 'PGjson)

1233−jsonExtractPathAsText x xs =

1234− unsafeVariadicFunction "json_extract_path_text" (x :* xs)

1235−

1236−-- | Returns JSON value pointed to by the given path (equivalent to #>

1237−-- operator), as text.

1238−jsonbExtractPathAsText

1239− :: SListI elems

1240− => Expression schema relations grouping params (nullity 'PGjsonb)

1241− -> NP (Expression schema relations grouping params) elems

1242− -> Expression schema relations grouping params (nullity 'PGjsonb)

1243−jsonbExtractPathAsText x xs =

1244− unsafeVariadicFunction "jsonb_extract_path_text" (x :* xs)

1245−

1246−-- | Returns set of keys in the outermost JSON object.

1247−jsonObjectKeys

1248− :: Expression schema relations grouping params (nullity 'PGjson)

1249− -> Expression schema relations grouping params (nullity 'PGtext)

1250−jsonObjectKeys = unsafeFunction "json_object_keys"

1251−

1252−-- | Returns set of keys in the outermost JSON object.

1253−jsonbObjectKeys

1254− :: Expression schema relations grouping params (nullity 'PGjsonb)

1255− -> Expression schema relations grouping params (nullity 'PGtext)

1256−jsonbObjectKeys = unsafeFunction "jsonb_object_keys"

1257−

1258−-- | Returns the type of the outermost JSON value as a text string. Possible

1259−-- types are object, array, string, number, boolean, and null.

1260−jsonTypeof

1261− :: Expression schema relations grouping params (nullity 'PGjson)

1262− -> Expression schema relations grouping params (nullity 'PGtext)

1263−jsonTypeof = unsafeFunction "json_typeof"

1264−

1265−-- | Returns the type of the outermost binary JSON value as a text string.

1266−-- Possible types are object, array, string, number, boolean, and null.

1267−jsonbTypeof

1268− :: Expression schema relations grouping params (nullity 'PGjsonb)

1269− -> Expression schema relations grouping params (nullity 'PGtext)

1270−jsonbTypeof = unsafeFunction "jsonb_typeof"

1271−

1272−-- | Returns its argument with all object fields that have null values omitted.

1273−-- Other null values are untouched.

1274−jsonStripNulls

1275− :: Expression schema relations grouping params (nullity 'PGjson)

1276− -> Expression schema relations grouping params (nullity 'PGjson)

1277−jsonStripNulls = unsafeFunction "json_strip_nulls"

1278−

1279−-- | Returns its argument with all object fields that have null values omitted.

1280−-- Other null values are untouched.

1281−jsonbStripNulls

1282− :: Expression schema relations grouping params (nullity 'PGjsonb)

1283− -> Expression schema relations grouping params (nullity 'PGjsonb)

1284−jsonbStripNulls = unsafeFunction "jsonb_strip_nulls"

1285−

1286−-- | @ jsonbSet target path new_value create_missing @

1287−--

1288−-- Returns target with the section designated by path replaced by new_value,

1289−-- or with new_value added if create_missing is true ( default is true) and the

1290−-- item designated by path does not exist. As with the path orientated

1291−-- operators, negative integers that appear in path count from the end of JSON

1292−-- arrays.

1293−jsonbSet

1294− :: PGtextArray "jsonbSet" arr

1295− => Expression schema relations grouping params (nullity 'PGjsonb)

1296− -> Expression schema relations grouping params (nullity arr)

1297− -> Expression schema relations grouping params (nullity 'PGjsonb)

1298− -> Maybe (Expression schema relations grouping params (nullity 'PGbool))

1299− -> Expression schema relations grouping params (nullity 'PGjsonb)

1300−jsonbSet tgt path val createMissing = case createMissing of

1301− Just m -> unsafeVariadicFunction "jsonb_set" (tgt :* path :* val :* m :* Nil)

1302− Nothing -> unsafeVariadicFunction "jsonb_set" (tgt :* path :* val :* Nil)

1303−

1304−-- | @ jsonbInsert target path new_value insert_after @

1305−--

1306−-- Returns target with new_value inserted. If target section designated by

1307−-- path is in a JSONB array, new_value will be inserted before target or after

1308−-- if insert_after is true (default is false). If target section designated by

1309−-- path is in JSONB object, new_value will be inserted only if target does not

1310−-- exist. As with the path orientated operators, negative integers that appear

1311−-- in path count from the end of JSON arrays.

1312−jsonbInsert

1313− :: PGtextArray "jsonbInsert" arr

1314− => Expression schema relations grouping params (nullity 'PGjsonb)

1315− -> Expression schema relations grouping params (nullity arr)

1316− -> Expression schema relations grouping params (nullity 'PGjsonb)

1317− -> Maybe (Expression schema relations grouping params (nullity 'PGbool))

1318− -> Expression schema relations grouping params (nullity 'PGjsonb)

1319−jsonbInsert tgt path val insertAfter = case insertAfter of

1320− Just i -> unsafeVariadicFunction "jsonb_insert" (tgt :* path :* val :* i :* Nil)

1321− Nothing -> unsafeVariadicFunction "jsonb_insert" (tgt :* path :* val :* Nil)

1322−

1323−-- | Returns its argument as indented JSON text.

1324−jsonbPretty

1325− :: Expression schema relations grouping params (nullity 'PGjsonb)

1326− -> Expression schema relations grouping params (nullity 'PGtext)

1327−jsonbPretty = unsafeFunction "jsonb_pretty"

1328−

1329−{-----------------------------------------

1330−aggregation

1331−-----------------------------------------}

1332−

1333−-- | escape hatch to define aggregate functions

1334−unsafeAggregate

1335− :: ByteString -- ^ aggregate function

1336− -> Expression schema relations 'Ungrouped params (xty)

1337− -> Expression schema relations ('Grouped bys) params (yty)

1338−unsafeAggregate fun x = UnsafeExpression $ mconcat

1339− [fun, "(", renderExpression x, ")"]

1340−

1341−-- | escape hatch to define aggregate functions over distinct values

1342−unsafeAggregateDistinct

1343− :: ByteString -- ^ aggregate function

1344− -> Expression schema relations 'Ungrouped params (xty)

1345− -> Expression schema relations ('Grouped bys) params (yty)

1346−unsafeAggregateDistinct fun x = UnsafeExpression $ mconcat

1347− [fun, "(DISTINCT ", renderExpression x, ")"]

1348−

1349−-- | >>> :{

1350−-- let

1351−-- expression :: Expression schema '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Grouped bys) params ('Null 'PGnumeric)

1352−-- expression = sum_ #col

1353−-- in printSQL expression

1354−-- :}

1355−-- sum("col")

1356−sum_

1357− :: PGNum ty

1358− => Expression schema relations 'Ungrouped params (nullity ty)

1359− -- ^ what to sum

1360− -> Expression schema relations ('Grouped bys) params (nullity ty)

1361−sum_ = unsafeAggregate "sum"

1362−

1363−-- | >>> :{

1364−-- let

1365−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGnumeric]] ('Grouped bys) params (nullity 'PGnumeric)

1366−-- expression = sumDistinct #col

1367−-- in printSQL expression

1368−-- :}

1369−-- sum(DISTINCT "col")

1370−sumDistinct

1371− :: PGNum ty

1372− => Expression schema relations 'Ungrouped params (nullity ty)

1373− -- ^ what to sum

1374− -> Expression schema relations ('Grouped bys) params (nullity ty)

1375−sumDistinct = unsafeAggregateDistinct "sum"

1376−

1377−-- | A constraint for `PGType`s that you can take averages of and the resulting

1378−-- `PGType`.

1379−class PGAvg ty avg | ty -> avg where

1380− avg, avgDistinct

1381− :: Expression schema relations 'Ungrouped params (nullity ty)

1382− -- ^ what to average

1383− -> Expression schema relations ('Grouped bys) params (nullity avg)

1384− avg = unsafeAggregate "avg"

1385− avgDistinct = unsafeAggregateDistinct "avg"

1386−instance PGAvg 'PGint2 'PGnumeric

1387−instance PGAvg 'PGint4 'PGnumeric

1388−instance PGAvg 'PGint8 'PGnumeric

1389−instance PGAvg 'PGnumeric 'PGnumeric

1390−instance PGAvg 'PGfloat4 'PGfloat8

1391−instance PGAvg 'PGfloat8 'PGfloat8

1392−instance PGAvg 'PGinterval 'PGinterval

1393−

1394−-- | >>> :{

1395−-- let

1396−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1397−-- expression = bitAnd #col

1398−-- in printSQL expression

1399−-- :}

1400−-- bit_and("col")

1401−bitAnd

1402− :: PGIntegral int

1403− => Expression schema relations 'Ungrouped params (nullity int)

1404− -- ^ what to aggregate

1405− -> Expression schema relations ('Grouped bys) params (nullity int)

1406−bitAnd = unsafeAggregate "bit_and"

1407−

1408−-- | >>> :{

1409−-- let

1410−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1411−-- expression = bitOr #col

1412−-- in printSQL expression

1413−-- :}

1414−-- bit_or("col")

1415−bitOr

1416− :: PGIntegral int

1417− => Expression schema relations 'Ungrouped params (nullity int)

1418− -- ^ what to aggregate

1419− -> Expression schema relations ('Grouped bys) params (nullity int)

1420−bitOr = unsafeAggregate "bit_or"

1421−

1422−-- | >>> :{

1423−-- let

1424−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1425−-- expression = bitAndDistinct #col

1426−-- in printSQL expression

1427−-- :}

1428−-- bit_and(DISTINCT "col")

1429−bitAndDistinct

1430− :: PGIntegral int

1431− => Expression schema relations 'Ungrouped params (nullity int)

1432− -- ^ what to aggregate

1433− -> Expression schema relations ('Grouped bys) params (nullity int)

1434−bitAndDistinct = unsafeAggregateDistinct "bit_and"

1435−

1436−-- | >>> :{

1437−-- let

1438−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

1439−-- expression = bitOrDistinct #col

1440−-- in printSQL expression

1441−-- :}

1442−-- bit_or(DISTINCT "col")

1443−bitOrDistinct

1444− :: PGIntegral int

1445− => Expression schema relations 'Ungrouped params (nullity int)

1446− -- ^ what to aggregate

1447− -> Expression schema relations ('Grouped bys) params (nullity int)

1448−bitOrDistinct = unsafeAggregateDistinct "bit_or"

1449−

1450−-- | >>> :{

1451−-- let

1452−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1453−-- expression = boolAnd #col

1454−-- in printSQL expression

1455−-- :}

1456−-- bool_and("col")

1457−boolAnd

1458− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1459− -- ^ what to aggregate

1460− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1461−boolAnd = unsafeAggregate "bool_and"

1462−

1463−-- | >>> :{

1464−-- let

1465−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1466−-- expression = boolOr #col

1467−-- in printSQL expression

1468−-- :}

1469−-- bool_or("col")

1470−boolOr

1471− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1472− -- ^ what to aggregate

1473− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1474−boolOr = unsafeAggregate "bool_or"

1475−

1476−-- | >>> :{

1477−-- let

1478−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1479−-- expression = boolAndDistinct #col

1480−-- in printSQL expression

1481−-- :}

1482−-- bool_and(DISTINCT "col")

1483−boolAndDistinct

1484− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1485− -- ^ what to aggregate

1486− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1487−boolAndDistinct = unsafeAggregateDistinct "bool_and"

1488−

1489−-- | >>> :{

1490−-- let

1491−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1492−-- expression = boolOrDistinct #col

1493−-- in printSQL expression

1494−-- :}

1495−-- bool_or(DISTINCT "col")

1496−boolOrDistinct

1497− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1498− -- ^ what to aggregate

1499− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1500−boolOrDistinct = unsafeAggregateDistinct "bool_or"

1501−

1502−-- | A special aggregation that does not require an input

1503−--

1504−-- >>> printSQL countStar

1505−-- count(*)

1506−countStar

1507− :: Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1508−countStar = UnsafeExpression $ "count(*)"

1509−

1510−-- | >>> :{

1511−-- let

1512−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1513−-- expression = count #col

1514−-- in printSQL expression

1515−-- :}

1516−-- count("col")

1517−count

1518− :: Expression schema relations 'Ungrouped params ty

1519− -- ^ what to count

1520− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1521−count = unsafeAggregate "count"

1522−

1523−-- | >>> :{

1524−-- let

1525−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1526−-- expression = countDistinct #col

1527−-- in printSQL expression

1528−-- :}

1529−-- count(DISTINCT "col")

1530−countDistinct

1531− :: Expression schema relations 'Ungrouped params ty

1532− -- ^ what to count

1533− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1534−countDistinct = unsafeAggregateDistinct "count"

1535−

1536−-- | synonym for `boolAnd`

1537−--

1538−-- >>> :{

1539−-- let

1540−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1541−-- expression = every #col

1542−-- in printSQL expression

1543−-- :}

1544−-- every("col")

1545−every

1546− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1547− -- ^ what to aggregate

1548− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1549−every = unsafeAggregate "every"

1550−

1551−-- | synonym for `boolAndDistinct`

1552−--

1553−-- >>> :{

1554−-- let

1555−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1556−-- expression = everyDistinct #col

1557−-- in printSQL expression

1558−-- :}

1559−-- every(DISTINCT "col")

1560−everyDistinct

1561− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1562− -- ^ what to aggregate

1563− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1564−everyDistinct = unsafeAggregateDistinct "every"

1565−

1566−-- | minimum and maximum aggregation

1567−max_, min_, maxDistinct, minDistinct

1568− :: Expression schema relations 'Ungrouped params (nullity ty)

1569− -- ^ what to aggregate

1570− -> Expression schema relations ('Grouped bys) params (nullity ty)

1571−max_ = unsafeAggregate "max"

1572−min_ = unsafeAggregate "min"

1573−maxDistinct = unsafeAggregateDistinct "max"

1574−minDistinct = unsafeAggregateDistinct "min"

1575−

1576−{-----------------------------------------

1577−type expressions

1578−-----------------------------------------}

1579−

1580−-- | `TypeExpression`s are used in `cast`s and `createTable` commands.

1581−newtype TypeExpression (schema :: SchemaType) (ty :: NullityType)

1582− = UnsafeTypeExpression { renderTypeExpression :: ByteString }

1583− deriving (GHC.Generic,Show,Eq,Ord,NFData)

1584−

1585−instance (Has alias schema ('Typedef ty))

1586− => IsLabel alias (TypeExpression schema (nullity ty)) where

1587− fromLabel = UnsafeTypeExpression (renderAlias (fromLabel @alias))

1588−

1589−-- | logical Boolean (true/false)

1590−bool :: TypeExpression schema (nullity 'PGbool)

1591−bool = UnsafeTypeExpression "bool"

1592−-- | signed two-byte integer

1593−int2, smallint :: TypeExpression schema (nullity 'PGint2)

1594−int2 = UnsafeTypeExpression "int2"

1595−smallint = UnsafeTypeExpression "smallint"

1596−-- | signed four-byte integer

1597−int4, int, integer :: TypeExpression schema (nullity 'PGint4)

1598−int4 = UnsafeTypeExpression "int4"

1599−int = UnsafeTypeExpression "int"

1600−integer = UnsafeTypeExpression "integer"

1601−-- | signed eight-byte integer

1602−int8, bigint :: TypeExpression schema (nullity 'PGint8)

1603−int8 = UnsafeTypeExpression "int8"

1604−bigint = UnsafeTypeExpression "bigint"

1605−-- | arbitrary precision numeric type

1606−numeric :: TypeExpression schema (nullity 'PGnumeric)

1607−numeric = UnsafeTypeExpression "numeric"

1608−-- | single precision floating-point number (4 bytes)

1609−float4, real :: TypeExpression schema (nullity 'PGfloat4)

1610−float4 = UnsafeTypeExpression "float4"

1611−real = UnsafeTypeExpression "real"

1612−-- | double precision floating-point number (8 bytes)

1613−float8, doublePrecision :: TypeExpression schema (nullity 'PGfloat8)

1614−float8 = UnsafeTypeExpression "float8"

1615−doublePrecision = UnsafeTypeExpression "double precision"

1616−-- | variable-length character string

1617−text :: TypeExpression schema (nullity 'PGtext)

1618−text = UnsafeTypeExpression "text"

1619−-- | fixed-length character string

1620−char, character

1621− :: forall n schema nullity. (KnownNat n, 1 <= n)

1622− => TypeExpression schema (nullity ('PGchar n))

1623−char = UnsafeTypeExpression $ "char(" <> renderNat @n <> ")"

1624−character = UnsafeTypeExpression $ "character(" <> renderNat @n <> ")"

1625−-- | variable-length character string

1626−varchar, characterVarying

1627− :: forall n schema nullity. (KnownNat n, 1 <= n)

1628− => TypeExpression schema (nullity ('PGvarchar n))

1629−varchar = UnsafeTypeExpression $ "varchar(" <> renderNat @n <> ")"

1630−characterVarying = UnsafeTypeExpression $

1631− "character varying(" <> renderNat @n <> ")"

1632−-- | binary data ("byte array")

1633−bytea :: TypeExpression schema (nullity 'PGbytea)

1634−bytea = UnsafeTypeExpression "bytea"

1635−-- | date and time (no time zone)

1636−timestamp :: TypeExpression schema (nullity 'PGtimestamp)

1637−timestamp = UnsafeTypeExpression "timestamp"

1638−-- | date and time, including time zone

1639−timestampWithTimeZone :: TypeExpression schema (nullity 'PGtimestamptz)

1640−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"

1641−-- | calendar date (year, month, day)

1642−date :: TypeExpression schema (nullity 'PGdate)

1643−date = UnsafeTypeExpression "date"

1644−-- | time of day (no time zone)

1645−time :: TypeExpression schema (nullity 'PGtime)

1646−time = UnsafeTypeExpression "time"

1647−-- | time of day, including time zone

1648−timeWithTimeZone :: TypeExpression schema (nullity 'PGtimetz)

1649−timeWithTimeZone = UnsafeTypeExpression "time with time zone"

1650−-- | time span

1651−interval :: TypeExpression schema (nullity 'PGinterval)

1652−interval = UnsafeTypeExpression "interval"

1653−-- | universally unique identifier

1654−uuid :: TypeExpression schema (nullity 'PGuuid)

1655−uuid = UnsafeTypeExpression "uuid"

1656−-- | IPv4 or IPv6 host address

1657−inet :: TypeExpression schema (nullity 'PGinet)

1658−inet = UnsafeTypeExpression "inet"

1659−-- | textual JSON data

1660−json :: TypeExpression schema (nullity 'PGjson)

1661−json = UnsafeTypeExpression "json"

1662−-- | binary JSON data, decomposed

1663−jsonb :: TypeExpression schema (nullity 'PGjsonb)

1664−jsonb = UnsafeTypeExpression "jsonb"

1665−-- | variable length array

1666−vararray

1667− :: TypeExpression schema pg

1668− -> TypeExpression schema (nullity ('PGvararray pg))

1669−vararray ty = UnsafeTypeExpression $ renderTypeExpression ty <> "[]"

1670−-- | fixed length array

1671−--

1672−-- >>> renderTypeExpression (fixarray @2 json)

1673−-- "json[2]"

1674−fixarray

1675− :: forall n schema nullity pg. KnownNat n

1676− => TypeExpression schema pg

1677− -> TypeExpression schema (nullity ('PGfixarray n pg))

1678−fixarray ty = UnsafeTypeExpression $

1679− renderTypeExpression ty <> "[" <> renderNat @n <> "]"

1680−

1681−-- | `pgtype` is a demoted version of a `PGType`

1682−class PGTyped schema (ty :: NullityType) where

1683− pgtype :: TypeExpression schema ty

1684−instance PGTyped schema (nullity 'PGbool) where pgtype = bool

1685−instance PGTyped schema (nullity 'PGint2) where pgtype = int2

1686−instance PGTyped schema (nullity 'PGint4) where pgtype = int4

1687−instance PGTyped schema (nullity 'PGint8) where pgtype = int8

1688−instance PGTyped schema (nullity 'PGnumeric) where pgtype = numeric

1689−instance PGTyped schema (nullity 'PGfloat4) where pgtype = float4

1690−instance PGTyped schema (nullity 'PGfloat8) where pgtype = float8

1691−instance PGTyped schema (nullity 'PGtext) where pgtype = text

1692−instance (KnownNat n, 1 <= n)

1693− => PGTyped schema (nullity ('PGchar n)) where pgtype = char @n

1694−instance (KnownNat n, 1 <= n)

1695− => PGTyped schema (nullity ('PGvarchar n)) where pgtype = varchar @n

1696−instance PGTyped schema (nullity 'PGbytea) where pgtype = bytea

1697−instance PGTyped schema (nullity 'PGtimestamp) where pgtype = timestamp

1698−instance PGTyped schema (nullity 'PGtimestamptz) where pgtype = timestampWithTimeZone

1699−instance PGTyped schema (nullity 'PGdate) where pgtype = date

1700−instance PGTyped schema (nullity 'PGtime) where pgtype = time

1701−instance PGTyped schema (nullity 'PGtimetz) where pgtype = timeWithTimeZone

1702−instance PGTyped schema (nullity 'PGinterval) where pgtype = interval

1703−instance PGTyped schema (nullity 'PGuuid) where pgtype = uuid

1704−instance PGTyped schema (nullity 'PGjson) where pgtype = json

1705−instance PGTyped schema (nullity 'PGjsonb) where pgtype = jsonb

1706−instance PGTyped schema ty

1707− => PGTyped schema (nullity ('PGvararray ty)) where

1708− pgtype = vararray (pgtype @schema @ty)

1709−instance (KnownNat n, PGTyped schema ty)

1710− => PGTyped schema (nullity ('PGfixarray n ty)) where

1711− 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+410−339

@@ -11,84 +11,139 @@ Squeal data manipulation language.

1111{-# LANGUAGE

1212 DeriveGeneric

1313 , FlexibleContexts

14+ , FlexibleInstances

1415 , GADTs

1516 , GeneralizedNewtypeDeriving

1617 , LambdaCase

18+ , MultiParamTypeClasses

1719 , OverloadedStrings

20+ , PatternSynonyms

21+ , QuantifiedConstraints

1822 , RankNTypes

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeFamilies

1926 , TypeInType

2027 , TypeOperators

28+ , UndecidableInstances

2129#-}

2230

2331module Squeal.PostgreSQL.Manipulation

2432 ( -- * Manipulation

25− Manipulation (UnsafeManipulation, renderManipulation)

33+ Manipulation_

34+ , Manipulation (..)

2635 , queryStatement

27− , ColumnValue (..)

28− , ReturningClause (ReturningStar, Returning)

29− , ConflictClause (OnConflictDoRaise, OnConflictDoNothing, OnConflictDoUpdate)

3036 -- * Insert

31− , insertRows

32− , insertRow

33− , insertRows_

34− , insertRow_

35− , insertQuery

36− , insertQuery_

37− , renderReturningClause

38− , renderConflictClause

37+ , insertInto

38+ , insertInto_

3939 -- * Update

4040 , update

4141 , update_

4242 -- * Delete

4343 , deleteFrom

4444 , deleteFrom_

45− -- * With

46− , with

45+ -- * Clauses

46+ , Optional (..)

47+ , QueryClause (..)

48+ , pattern Values_

49+ , ReturningClause (..)

50+ , pattern Returning_

51+ , ConflictClause (..)

52+ , ConflictTarget (..)

53+ , ConflictAction (..)

54+ , UsingClause (..)

4755 ) where

4856

4957import Control.DeepSeq

5058import Data.ByteString hiding (foldr)

51−import Data.Monoid

59+import Data.Kind (Type)

5260

5361import qualified Generics.SOP as SOP

5462import qualified GHC.Generics as GHC

5563

64+import Squeal.PostgreSQL.Alias

5665import Squeal.PostgreSQL.Expression

66+import Squeal.PostgreSQL.Expression.Logic

67+import Squeal.PostgreSQL.List

68+import Squeal.PostgreSQL.PG

5769import Squeal.PostgreSQL.Render

5870import Squeal.PostgreSQL.Query

5971import Squeal.PostgreSQL.Schema

6072

73+-- $setup

74+-- >>> import Squeal.PostgreSQL

75+-- >>> import Data.Int

76+-- >>> import Data.Time

77+

6178{- |

6279A `Manipulation` is a statement which may modify data in the database,

63−but does not alter the schema. Examples are inserts, updates and deletes.

80+but does not alter its schemas. Examples are inserts, updates and deletes.

6481A `Query` is also considered a `Manipulation` even though it does not modify data.

6582

83+The general `Manipulation` type is parameterized by

84+

85+* @commons :: FromType@ - scope for all `common` table expressions,

86+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

87+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

88+* @row :: RowType@ - return type of the `Query`.

89+-}

90+newtype Manipulation

91+ (commons :: FromType)

92+ (schemas :: SchemasType)

93+ (params :: [NullityType])

94+ (columns :: RowType)

95+ = UnsafeManipulation { renderManipulation :: ByteString }

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

97+instance RenderSQL (Manipulation commons schemas params columns) where

98+ renderSQL = renderManipulation

99+instance With Manipulation where

100+ with Done manip = manip

101+ with ctes manip = UnsafeManipulation $

102+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL manip

103+

104+{- |

105+The top level `Manipulation_` type is parameterized by a @schemas@ `SchemasType`,

106+against which the query is type-checked, an input @parameters@ Haskell `Type`,

107+and an ouput row Haskell `Type`.

108+

109+A top-level `Manipulation_` can be run

110+using `Squeal.PostgreSQL.PQ.manipulateParams`, or if @parameters = ()@

111+using `Squeal.PostgreSQL.PQ.manipulate`.

112+

113+Generally, @parameters@ will be a Haskell tuple or record whose entries

114+may be referenced using positional

115+`Squeal.PostgreSQL.Expression.Parameter.parameter`s and @row@ will be a

116+Haskell record, whose entries will be targeted using overloaded labels.

117+

118+>>> :set -XDeriveAnyClass -XDerivingStrategies

119+>>> :{

120+data Row a b = Row { col1 :: a, col2 :: b }

121+ deriving stock (GHC.Generic)

122+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

123+:}

124+

66125simple insert:

67126

127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]

128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

68129>>> :{

69130let

70− manipulation :: Manipulation

71− '[ "tab" ::: 'Table ('[] :=>

72− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

73− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[] '[]

131+ manipulation :: Manipulation_ (Public Schema) () ()

74132 manipulation =

75− insertRow_ #tab (Set 2 `as` #col1 :* Default `as` #col2)

133+ insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))

76134in printSQL manipulation

77135:}

78136INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)

79137

80138parameterized insert:

81139

140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

82142>>> :{

83143let

84− manipulation :: Manipulation

85− '[ "tab" ::: 'Table ('[] :=>

86− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

87− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

88− '[ 'NotNull 'PGint4, 'NotNull 'PGint4 ] '[]

144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()

89145 manipulation =

90− insertRow_ #tab

91− (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2)

146+ insertInto_ #tab (Values_ (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2))

92147in printSQL manipulation

93148:}

94149INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))

@@ -97,71 +152,48 @@ returning insert:

97152

98153>>> :{

99154let

100− manipulation :: Manipulation

101− '[ "tab" ::: 'Table ('[] :=>

102− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

103− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[]

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

155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)

105156 manipulation =

106− insertRow #tab (Set 2 `as` #col1 :* Default `as` #col2)

157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))

107158 OnConflictDoRaise (Returning (#col1 `as` #fromOnly))

108159in printSQL manipulation

109160:}

110−INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT) RETURNING "col1" AS "fromOnly"

161+INSERT INTO "tab" ("col1", "col2") VALUES (2, 3) RETURNING "col1" AS "fromOnly"

111162

112163upsert:

113164

165+>>> type CustomersColumns = '["name" ::: 'NoDef :=> 'NotNull 'PGtext, "email" ::: 'NoDef :=> 'NotNull 'PGtext]

166+>>> type CustomersConstraints = '["uq" ::: 'Unique '["name"]]

167+>>> type CustomersSchema = '["customers" ::: 'Table (CustomersConstraints :=> CustomersColumns)]

114168>>> :{

115169let

116− manipulation :: Manipulation

117− '[ "tab" ::: 'Table ('[] :=>

118− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

119− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

120− '[] '[ "sum" ::: 'NotNull 'PGint4]

170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()

121171 manipulation =

122− insertRows #tab

123− (Set 2 `as` #col1 :* Set 4 `as` #col2)

124− [Set 6 `as` #col1 :* Set 8 `as` #col2]

125− (OnConflictDoUpdate

126− (Set 2 `as` #col1 :* Same `as` #col2)

127− [#col1 .== #col2])

128− (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)

129177in printSQL manipulation

130178:}

131−INSERT INTO "tab" ("col1", "col2") VALUES (2, 4), (6, 8) ON CONFLICT DO UPDATE SET "col1" = 2 WHERE ("col1" = "col2") RETURNING ("col1" + "col2") AS "sum"

179+INSERT INTO "customers" ("name", "email") VALUES (E'John Smith', E'john@smith.com') ON CONFLICT ON CONSTRAINT "uq" DO UPDATE SET "email" = ("excluded"."email" || (E'; ' || "customers"."email"))

132180

133181query insert:

134182

135183>>> :{

136184let

137− manipulation :: Manipulation

138− '[ "tab" ::: 'Table ('[] :=>

139− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

140− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

141− ])

142− , "other_tab" ::: 'Table ('[] :=>

143− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

144− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

145− ])

146− ] '[] '[]

147− manipulation =

148− insertQuery_ #tab

149− (selectStar (from (table (#other_tab `as` #t))))

185+ manipulation :: Manipulation_ (Public Schema) () ()

186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))

150187in printSQL manipulation

151188:}

152−INSERT INTO "tab" SELECT * FROM "other_tab" AS "t"

189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"

153190

154191update:

155192

156193>>> :{

157194let

158− manipulation :: Manipulation

159− '[ "tab" ::: 'Table ('[] :=>

160− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

161− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[] '[]

162− manipulation =

163− update_ #tab (Set 2 `as` #col1 :* Same `as` #col2)

164− (#col1 ./= #col2)

195+ manipulation :: Manipulation_ (Public Schema) () ()

196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)

165197in printSQL manipulation

166198:}

167199UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")

@@ -170,154 +202,178 @@ delete:

170202

171203>>> :{

172204let

173− manipulation :: Manipulation

174− '[ "tab" ::: 'Table ('[] :=>

175− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

176− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[]

177− '[ "col1" ::: 'NotNull 'PGint4

178− , "col2" ::: 'NotNull 'PGint4 ]

179− manipulation = deleteFrom #tab (#col1 .== #col2) ReturningStar

205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)

206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)

180207in printSQL manipulation

181208:}

182209DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *

183−-}

184−newtype Manipulation

185− (schema :: SchemaType)

186− (params :: [NullityType])

187− (columns :: RelationType)

188− = UnsafeManipulation { renderManipulation :: ByteString }

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

190210

191−instance RenderSQL (Manipulation schema params columns) where

192− renderSQL = renderManipulation

211+delete and using clause:

212+

213+>>> :{

214+type Schema3 =

215+ '[ "tab" ::: 'Table ('[] :=> Columns)

216+ , "other_tab" ::: 'Table ('[] :=> Columns)

217+ , "third_tab" ::: 'Table ('[] :=> Columns) ]

218+:}

219+

220+>>> :{

221+let

222+ manipulation :: Manipulation_ (Public Schema3) () ()

223+ manipulation =

224+ deleteFrom #tab (Using (table #other_tab & also (table #third_tab)))

225+ ( (#tab ! #col2 .== #other_tab ! #col2)

226+ .&& (#tab ! #col2 .== #third_tab ! #col2) )

227+ (Returning_ Nil)

228+in printSQL manipulation

229+:}

230+DELETE FROM "tab" USING "other_tab" AS "other_tab", "third_tab" AS "third_tab" WHERE (("tab"."col2" = "other_tab"."col2") AND ("tab"."col2" = "third_tab"."col2"))

231+

232+with manipulation:

233+

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

235+>>> type ProductsSchema = '["products" ::: 'Table ('[] :=> ProductsColumns), "products_deleted" ::: 'Table ('[] :=> ProductsColumns)]

236+>>> :{

237+let

238+ manipulation :: Manipulation_ (Public ProductsSchema) (Only Day) ()

239+ manipulation = with

240+ (deleteFrom #products NoUsing (#date .< param @1) (Returning Star) `as` #del)

241+ (insertInto_ #products_deleted (Subquery (select Star (from (common #del)))))

242+in printSQL manipulation

243+:}

244+WITH "del" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "del" AS "del"

245+-}

246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where

247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)

193248

194249-- | Convert a `Query` into a `Manipulation`.

195250queryStatement

196− :: Query schema params columns

197− -> Manipulation schema params columns

198−queryStatement q = UnsafeManipulation $ renderQuery q

251+ :: Query '[] commons schemas params columns

252+ -- ^ `Query` to embed as a `Manipulation`

253+ -> Manipulation commons schemas params columns

254+queryStatement q = UnsafeManipulation $ renderSQL q

199255

200256{-----------------------------------------

201257INSERT statements

202258-----------------------------------------}

203259

204−-- | Insert multiple rows.

205−--

206−-- When a table is created, it contains no data. The first thing to do

207−-- before a database can be of much use is to insert data. Data is

208−-- conceptually inserted one row at a time. Of course you can also insert

209−-- more than one row, but there is no way to insert less than one row.

210−-- Even if you know only some column values, a complete row must be created.

211−insertRows

212− :: ( SOP.SListI columns

213− , SOP.SListI results

214− , Has tab schema ('Table table)

215− , columns ~ TableToColumns table )

216− => Alias tab -- ^ table to insert into

217− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

218− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

219− -> ConflictClause schema columns params

220− -- ^ what to do in case of constraint conflict

221− -> ReturningClause schema columns params results -- ^ results to return

222− -> Manipulation schema params results

223−insertRows tab rw rws conflict returning = UnsafeManipulation $

224− "INSERT" <+> "INTO" <+> renderAlias tab

225− <+> parenthesized (renderCommaSeparated renderAliasPart rw)

226− <+> "VALUES"

227− <+> commaSeparated

228− ( parenthesized

229− . renderCommaSeparated renderColumnValuePart <$> rw:rws )

230− <> renderConflictClause conflict

231− <> renderReturningClause returning

232− where

233− renderAliasPart, renderColumnValuePart

234− :: Aliased (ColumnValue schema '[] params) ty -> ByteString

235− renderAliasPart (_ `As` name) = renderAlias name

236− renderColumnValuePart (value `As` _) = case value of

237− Default -> "DEFAULT"

238− Set expression -> renderExpression expression

239−

240−-- | Insert a single row.

241−insertRow

242− :: ( SOP.SListI columns

243− , SOP.SListI results

244− , Has tab schema ('Table table)

245− , columns ~ TableToColumns table )

246− => Alias tab -- ^ table to insert into

247− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

248− -> ConflictClause schema columns params

249− -- ^ what to do in case of constraint conflict

250− -> ReturningClause schema columns params results -- ^ results to return

251− -> Manipulation schema params results

252−insertRow tab rw = insertRows tab rw []

253−

254−-- | Insert multiple rows returning `Nil` and raising an error on conflicts.

255−insertRows_

256− :: ( SOP.SListI columns

257− , Has tab schema ('Table table)

258− , columns ~ TableToColumns table )

259− => Alias tab -- ^ table to insert into

260− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

261− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

262− -> Manipulation schema params '[]

263−insertRows_ tab rw rws =

264− insertRows tab rw rws OnConflictDoRaise (Returning Nil)

265−

266−-- | Insert a single row returning `Nil` and raising an error on conflicts.

267−insertRow_

268− :: ( SOP.SListI columns

269− , Has tab schema ('Table table)

270− , columns ~ TableToColumns table )

271− => Alias tab -- ^ table to insert into

272− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

273− -> Manipulation schema params '[]

274−insertRow_ tab rw = insertRow tab rw OnConflictDoRaise (Returning Nil)

275−

276−-- | Insert a `Query`.

277−insertQuery

278− :: ( SOP.SListI columns

279− , SOP.SListI results

260+{- |

261+When a table is created, it contains no data. The first thing to do

262+before a database can be of much use is to insert data. Data is

263+conceptually inserted one row at a time. Of course you can also insert

264+more than one row, but there is no way to insert less than one row.

265+Even if you know only some column values, a complete row must be created.

266+-}

267+insertInto

268+ :: ( Has sch schemas schema

280269 , Has tab schema ('Table table)

281− , columns ~ TableToColumns table )

282− => Alias tab -- ^ table to insert into

283− -> Query schema params (ColumnsToRelation columns)

284− -> ConflictClause schema columns params

285− -- ^ what to do in case of constraint conflict

286− -> ReturningClause schema columns params results -- ^ results to return

287− -> Manipulation schema params results

288−insertQuery tab query conflict returning = UnsafeManipulation $

289− "INSERT" <+> "INTO" <+> renderAlias tab

290− <+> renderQuery query

291− <> renderConflictClause conflict

292− <> renderReturningClause returning

293−

294−-- | Insert a `Query` returning `Nil` and raising an error on conflicts.

295−insertQuery_

296− :: ( SOP.SListI columns

270+ , columns ~ TableToColumns table

271+ , row0 ~ TableToRow table

272+ , SOP.SListI columns

273+ , SOP.SListI row1 )

274+ => QualifiedAlias sch tab

275+ -- ^ table

276+ -> QueryClause commons schemas params columns

277+ -- ^ what to insert

278+ -> ConflictClause tab commons schemas params table

279+ -- ^ what to do in case of conflict

280+ -> ReturningClause commons schemas params '[tab ::: row0] row1

281+ -- ^ what to return

282+ -> Manipulation commons schemas params row1

283+insertInto tab qry conflict ret = UnsafeManipulation $

284+ "INSERT" <+> "INTO" <+> renderSQL tab

285+ <+> renderSQL qry

286+ <> renderSQL conflict

287+ <> renderSQL ret

288+

289+-- | Like `insertInto` but with `OnConflictDoRaise` and `no` `ReturningClause`.

290+insertInto_

291+ :: ( Has sch schemas schema

297292 , Has tab schema ('Table table)

298− , columns ~ TableToColumns table )

299− => Alias tab -- ^ table to insert into

300− -> Query schema params (ColumnsToRelation columns)

301− -> Manipulation schema params '[]

302−insertQuery_ tab query =

303− insertQuery tab query OnConflictDoRaise (Returning Nil)

304−

305−-- | `ColumnValue`s are values to insert or update in a row.

306−-- `Same` updates with the same value.

307−-- `Default` inserts or updates with the @DEFAULT@ value.

308−-- `Set` sets a value to be an `Expression`, which can refer to

309−-- existing value in the row for an update.

310−data ColumnValue

311− (schema :: SchemaType)

312− (columns :: RelationType)

313− (params :: [NullityType])

314− (ty :: ColumnType)

315− where

316− Same :: ColumnValue schema (column ': columns) params ty

317− Default :: ColumnValue schema columns params ('Def :=> ty)

318− Set

319− :: (forall table. Expression schema '[table ::: columns] 'Ungrouped params ty)

320− -> ColumnValue schema columns params (constraint :=> ty)

293+ , columns ~ TableToColumns table

294+ , row ~ TableToRow table

295+ , SOP.SListI columns )

296+ => QualifiedAlias sch tab

297+ -- ^ table

298+ -> QueryClause commons schemas params columns

299+ -- ^ what to insert

300+ -> Manipulation commons schemas params '[]

301+insertInto_ tab qry =

302+ insertInto tab qry OnConflictDoRaise (Returning_ Nil)

303+

304+-- | A `QueryClause` describes what to `insertInto` a table.

305+data QueryClause commons schemas params columns where

306+ Values

307+ :: SOP.SListI columns

308+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

309+ -- ^ row of values

310+ -> [NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns]

311+ -- ^ additional rows of values

312+ -> QueryClause commons schemas params columns

313+ Select

314+ :: SOP.SListI columns

315+ => NP (Aliased (Optional (Expression '[] commons grp schemas params from))) columns

316+ -- ^ row of values

317+ -> TableExpression '[] commons grp schemas params from

318+ -- ^ from a table expression

319+ -> QueryClause commons schemas params columns

320+ Subquery

321+ :: ColumnsToRow columns ~ row

322+ => Query '[] commons schemas params row

323+ -- ^ subquery to insert

324+ -> QueryClause commons schemas params columns

325+

326+instance RenderSQL (QueryClause commons schemas params columns) where

327+ renderSQL = \case

328+ Values row0 rows ->

329+ parenthesized (renderCommaSeparated renderSQLPart row0)

330+ <+> "VALUES"

331+ <+> commaSeparated

332+ ( parenthesized

333+ . renderCommaSeparated renderValuePart <$> row0 : rows )

334+ Select row0 tab ->

335+ parenthesized (renderCommaSeparatedMaybe renderSQLPartMaybe row0)

336+ <+> "SELECT"

337+ <+> renderCommaSeparatedMaybe renderValuePartMaybe row0

338+ <+> renderSQL tab

339+ Subquery qry -> renderQuery qry

340+ where

341+ renderSQLPartMaybe, renderValuePartMaybe

342+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

343+ -> Maybe ByteString

344+ renderSQLPartMaybe = \case

345+ Default `As` _ -> Nothing

346+ Set _ `As` name -> Just $ renderSQL name

347+ renderValuePartMaybe = \case

348+ Default `As` _ -> Nothing

349+ Set value `As` _ -> Just $ renderExpression value

350+ renderSQLPart, renderValuePart

351+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

352+ -> ByteString

353+ renderSQLPart (_ `As` name) = renderSQL name

354+ renderValuePart (value `As` _) = renderSQL value

355+

356+-- | `Values_` describes a single `NP` list of `Aliased` `Optional` `Expression`s

357+-- whose `ColumnsType` must match the tables'.

358+pattern Values_

359+ :: SOP.SListI columns

360+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

361+ -- ^ row of values

362+ -> QueryClause commons schemas params columns

363+pattern Values_ vals = Values vals []

364+

365+-- | `Optional` is either `Default` or a value, parameterized by an appropriate

366+-- `ColumnConstraint`.

367+data Optional expr ty where

368+ -- | Use the `Default` value for a column.

369+ Default :: Optional expr ('Def :=> ty)

370+ -- | `Set` a value for a column.

371+ Set :: expr ty -> Optional expr (def :=> ty)

372+

373+instance (forall x. RenderSQL (expr x)) => RenderSQL (Optional expr ty) where

374+ renderSQL = \case

375+ Default -> "DEFAULT"

376+ Set expr -> renderSQL expr

321377

322378-- | A `ReturningClause` computes and return value(s) based

323379-- on each row actually inserted, updated or deleted. This is primarily

@@ -325,72 +381,100 @@ data ColumnValue

325381-- serial sequence number. However, any expression using the table's columns

326382-- is allowed. Only rows that were successfully inserted or updated or

327383-- deleted will be returned. For example, if a row was locked

328−-- but not updated because an `OnConflictDoUpdate` condition was not satisfied,

329−-- the row will not be returned. `ReturningStar` will return all columns

330−-- in the row. Use @Returning Nil@ in the common case where no return

384+-- but not updated because an `OnConflict` `DoUpdate` condition was not satisfied,

385+-- the row will not be returned. `Returning` `Star` will return all columns

386+-- in the row. Use `Returning` `Nil` in the common case where no return

331387-- values are desired.

332−data ReturningClause

333− (schema :: SchemaType)

334− (columns :: ColumnsType)

335− (params :: [NullityType])

336− (results :: RelationType)

337− where

338− ReturningStar

339− :: results ~ ColumnsToRelation columns

340− => ReturningClause schema columns params results

341− Returning

342− :: rel ~ ColumnsToRelation columns

343− => NP (Aliased (Expression schema '[table ::: rel] 'Ungrouped params)) results

344− -> ReturningClause schema columns params results

345−

346−-- | Render a `ReturningClause`.

347−renderReturningClause

348− :: SOP.SListI results

349− => ReturningClause schema params columns results

350− -> ByteString

351−renderReturningClause = \case

352− ReturningStar -> " RETURNING *"

353− Returning Nil -> ""

354− Returning results -> " RETURNING"

355− <+> renderCommaSeparated (renderAliasedAs renderExpression) results

388+newtype ReturningClause commons schemas params from row =

389+ Returning (Selection '[] commons 'Ungrouped schemas params from row)

390+

391+instance RenderSQL (ReturningClause commons schemas params from row) where

392+ renderSQL = \case

393+ Returning (List Nil) -> ""

394+ Returning selection -> " RETURNING" <+> renderSQL selection

395+

396+-- | `Returning` a `List`

397+pattern Returning_

398+ :: SOP.SListI row

399+ => NP (Aliased (Expression '[] commons 'Ungrouped schemas params from)) row

400+ -- ^ row of values

401+ -> ReturningClause commons schemas params from row

402+pattern Returning_ list = Returning (List list)

356403

357404-- | A `ConflictClause` specifies an action to perform upon a constraint

358405-- violation. `OnConflictDoRaise` will raise an error.

359−-- `OnConflictDoNothing` simply avoids inserting a row.

360−-- `OnConflictDoUpdate` updates the existing row that conflicts with the row

406+-- `OnConflict` `DoNothing` simply avoids inserting a row.

407+-- `OnConflict` `DoUpdate` updates the existing row that conflicts with the row

361408-- proposed for insertion.

362−data ConflictClause (schema :: SchemaType) (columns :: ColumnsType) params where

363− OnConflictDoRaise :: ConflictClause schema columns params

364− OnConflictDoNothing :: ConflictClause schema columns params

365− OnConflictDoUpdate

366− :: NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

367− -> [Condition schema '[table ::: ColumnsToRelation columns] 'Ungrouped params]

368− -> ConflictClause schema columns params

409+data ConflictClause tab commons schemas params table where

410+ OnConflictDoRaise :: ConflictClause tab commons schemas params table

411+ OnConflict

412+ :: ConflictTarget constraints

413+ -- ^ conflict target

414+ -> ConflictAction tab commons schemas params columns

415+ -- ^ conflict action

416+ -> ConflictClause tab commons schemas params (constraints :=> columns)

369417

370418-- | Render a `ConflictClause`.

371−renderConflictClause

372− :: SOP.SListI columns

373− => ConflictClause schema columns params

419+instance SOP.SListI (TableToColumns table)

420+ => RenderSQL (ConflictClause tab commons schemas params table) where

421+ renderSQL = \case

422+ OnConflictDoRaise -> ""

423+ OnConflict target action -> " ON CONFLICT"

424+ <+> renderSQL target <+> renderSQL action

425+

426+{- |

427+`ConflictAction` specifies an alternative `OnConflict` action.

428+It can be either `DoNothing`, or a `DoUpdate` clause specifying

429+the exact details of the `update` action to be performed in case of a conflict.

430+The `Set` and WHERE `Condition`s in `OnConflict` `DoUpdate` have access to the

431+existing row using the table's name (or an alias), and to rows proposed

432+for insertion using the special @#excluded@ table.

433+`OnConflict` `DoNothing` simply avoids inserting a row as its alternative action.

434+`OnConflict` `DoUpdate` updates the existing row that conflicts

435+with the row proposed for insertion as its alternative action.

436+-}

437+data ConflictAction tab commons schemas params columns where

438+ DoNothing :: ConflictAction tab commons schemas params columns

439+ DoUpdate

440+ :: ( row ~ ColumnsToRow columns

441+ , SOP.SListI columns

442+ , columns ~ (col0 ': cols)

443+ , SOP.All (HasIn columns) subcolumns

444+ , AllUnique subcolumns )

445+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]))) subcolumns

446+ -> [Condition '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]]

447+ -- ^ WHERE `Condition`s

448+ -> ConflictAction tab commons schemas params columns

449+

450+instance RenderSQL (ConflictAction tab commons schemas params columns) where

451+ renderSQL = \case

452+ DoNothing -> "DO NOTHING"

453+ DoUpdate updates whs'

454+ -> "DO UPDATE SET"

455+ <+> renderCommaSeparated renderUpdate updates

456+ <> case whs' of

457+ [] -> ""

458+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

459+

460+renderUpdate

461+ :: (forall x. RenderSQL (expr x))

462+ => Aliased (Optional expr) ty

374463 -> ByteString

375−renderConflictClause = \case

376− OnConflictDoRaise -> ""

377− OnConflictDoNothing -> " ON CONFLICT DO NOTHING"

378− OnConflictDoUpdate updates whs'

379− -> " ON CONFLICT DO UPDATE SET"

380− <+> renderCommaSeparatedMaybe renderUpdate updates

381− <> case whs' of

382− [] -> ""

383− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

384− where

385− renderUpdate

386− :: Aliased (ColumnValue schema columns params) column

387− -> Maybe ByteString

388− renderUpdate = \case

389− Same `As` _ -> Nothing

390− Default `As` column -> Just $

391− renderAlias column <+> "=" <+> "DEFAULT"

392− Set expression `As` column -> Just $

393− renderAlias column <+> "=" <+> renderExpression expression

464+renderUpdate (expr `As` col) = renderSQL col <+> "=" <+> renderSQL expr

465+

466+-- | A `ConflictTarget` specifies the constraint violation that triggers a

467+-- `ConflictAction`.

468+data ConflictTarget constraints where

469+ OnConstraint

470+ :: Has con constraints constraint

471+ => Alias con

472+ -> ConflictTarget constraints

473+

474+-- | Render a `ConflictTarget`

475+instance RenderSQL (ConflictTarget constraints) where

476+ renderSQL (OnConstraint con) =

477+ "ON" <+> "CONSTRAINT" <+> renderSQL con

394478

395479{-----------------------------------------

396480UPDATE statements

@@ -400,108 +484,95 @@ UPDATE statements

400484-- in all rows that satisfy the condition.

401485update

402486 :: ( SOP.SListI columns

403− , SOP.SListI results

487+ , SOP.SListI row1

488+ , Has sch schemas schema

404489 , Has tab schema ('Table table)

405− , columns ~ TableToColumns table )

406− => Alias tab -- ^ table to update

407− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

490+ , row0 ~ TableToRow table

491+ , columns ~ TableToColumns table

492+ , SOP.All (HasIn columns) subcolumns

493+ , AllUnique subcolumns )

494+ => QualifiedAlias sch tab -- ^ table to update

495+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row0]))) subcolumns

408496 -- ^ modified values to replace old values

409− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

497+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row0]

410498 -- ^ condition under which to perform update on a row

411− -> ReturningClause schema columns params results -- ^ results to return

412− -> Manipulation schema params results

499+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

500+ -> Manipulation commons schemas params row1

413501update tab columns wh returning = UnsafeManipulation $

414502 "UPDATE"

415− <+> renderAlias tab

503+ <+> renderSQL tab

416504 <+> "SET"

417− <+> renderCommaSeparatedMaybe renderUpdate columns

418− <+> "WHERE" <+> renderExpression wh

419− <> renderReturningClause returning

420− where

421− renderUpdate

422− :: Aliased (ColumnValue schema columns params) column

423− -> Maybe ByteString

424− renderUpdate = \case

425− Same `As` _ -> Nothing

426− Default `As` column -> Just $

427− renderAlias column <+> "=" <+> "DEFAULT"

428− Set expression `As` column -> Just $

429− renderAlias column <+> "=" <+> renderExpression expression

505+ <+> renderCommaSeparated renderUpdate columns

506+ <+> "WHERE" <+> renderSQL wh

507+ <> renderSQL returning

430508

431509-- | Update a row returning `Nil`.

432510update_

433511 :: ( SOP.SListI columns

512+ , Has sch schemas schema

434513 , Has tab schema ('Table table)

435− , columns ~ TableToColumns table )

436− => Alias tab -- ^ table to update

437− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

514+ , row ~ TableToRow table

515+ , columns ~ TableToColumns table

516+ , SOP.All (HasIn columns) subcolumns

517+ , AllUnique subcolumns )

518+ => QualifiedAlias sch tab -- ^ table to update

519+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row]))) subcolumns

438520 -- ^ modified values to replace old values

439− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

521+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

440522 -- ^ condition under which to perform update on a row

441− -> Manipulation schema params '[]

442−update_ tab columns wh = update tab columns wh (Returning Nil)

523+ -> Manipulation commons schemas params '[]

524+update_ tab columns wh = update tab columns wh (Returning_ Nil)

443525

444526{-----------------------------------------

445527DELETE statements

446528-----------------------------------------}

447529

448−-- | Delete rows of a table.

530+-- | Specify additional tables with `Using`

531+-- an `also` list of table expressions, allowing columns

532+-- from other tables to appear in the WHERE condition.

533+-- This is similar to the list of tables that can be specified

534+-- in the FROM Clause of a SELECT statement;

535+-- for example, an alias for the table name can be specified.

536+-- Do not repeat the target table in the `Using` list,

537+-- unless you wish to set up a self-join.

538+-- `NoUsing` if no additional tables are to be used.

539+data UsingClause commons schemas params from where

540+ NoUsing :: UsingClause commons schemas params '[]

541+ Using

542+ :: FromClause '[] commons schemas params from

543+ -- ^ what to use

544+ -> UsingClause commons schemas params from

545+

546+-- | Delete rows from a table.

449547deleteFrom

450− :: ( SOP.SListI results

548+ :: ( SOP.SListI row1

549+ , Has sch schemas schema

451550 , Has tab schema ('Table table)

551+ , row0 ~ TableToRow table

452552 , columns ~ TableToColumns table )

453− => Alias tab -- ^ table to delete from

454− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

553+ => QualifiedAlias sch tab -- ^ table to delete from

554+ -> UsingClause commons schemas params from

555+ -> Condition '[] commons 'Ungrouped schemas params (tab ::: row0 ': from)

455556 -- ^ condition under which to delete a row

456− -> ReturningClause schema columns params results -- ^ results to return

457− -> Manipulation schema params results

458−deleteFrom tab wh returning = UnsafeManipulation $

459− "DELETE FROM" <+> renderAlias tab

460− <+> "WHERE" <+> renderExpression wh

461− <> renderReturningClause returning

557+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

558+ -> Manipulation commons schemas params row1

559+deleteFrom tab using wh returning = UnsafeManipulation $

560+ "DELETE FROM"

561+ <+> renderSQL tab

562+ <> case using of

563+ NoUsing -> ""

564+ Using tables -> " USING" <+> renderSQL tables

565+ <+> "WHERE" <+> renderSQL wh

566+ <> renderSQL returning

462567

463568-- | Delete rows returning `Nil`.

464569deleteFrom_

465− :: ( Has tab schema ('Table table)

570+ :: ( Has sch schemas schema

571+ , Has tab schema ('Table table)

572+ , row ~ TableToRow table

466573 , columns ~ TableToColumns table )

467− => Alias tab -- ^ table to delete from

468− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

574+ => QualifiedAlias sch tab -- ^ table to delete from

575+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

469576 -- ^ condition under which to delete a row

470− -> Manipulation schema params '[]

471−deleteFrom_ tab wh = deleteFrom tab wh (Returning Nil)

472−

473−{-----------------------------------------

474−WITH statements

475−-----------------------------------------}

476−

477−-- | `with` provides a way to write auxiliary statements for use in a larger statement.

478−-- These statements, which are often referred to as Common Table Expressions or CTEs,

479−-- can be thought of as defining temporary tables that exist just for one statement.

480−--

481−-- >>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

482−--

483−-- >>> :{

484−-- let

485−-- manipulation :: Manipulation '["products" ::: 'Table ProductsTable, "products_deleted" ::: 'Table ProductsTable] '[ 'NotNull 'PGdate] '[]

486−-- manipulation = with

487−-- (deleteFrom #products (#date .< param @1) ReturningStar `as` #deleted_rows)

488−-- (insertQuery_ #products_deleted (selectStar (from (view (#deleted_rows `as` #t)))))

489−-- in printSQL manipulation

490−-- :}

491−-- WITH "deleted_rows" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "deleted_rows" AS "t"

492−with

493− :: SOP.SListI commons

494− => NP (Aliased (Manipulation schema params)) (common ': commons)

495− -- ^ common table expressions

496− -> Manipulation (With (common ': commons) schema) params results

497− -> Manipulation schema params results

498−with commons manipulation = UnsafeManipulation $

499− "WITH" <+> renderCommaSeparated renderCommon commons

500− <+> renderManipulation manipulation

501− where

502− renderCommon

503− :: Aliased (Manipulation schema params) common

504− -> ByteString

505− renderCommon (common `As` alias) =

506− renderAlias alias <+> "AS" <+>

507− parenthesized (renderManipulation common)

577+ -> Manipulation commons schemas params '[]

578+deleteFrom_ tab wh = deleteFrom tab NoUsing wh (Returning_ Nil)

squeal-postgresql/src/Squeal/PostgreSQL/Migration.hs+338−206

@@ -8,8 +8,13 @@ Stability: experimental

88This module defines a `Migration` type to safely

99change the schema of your database over time. Let's see an example!

1010

11+First turn on some extensions.

12+

1113>>> :set -XDataKinds -XOverloadedLabels

1214>>> :set -XOverloadedStrings -XFlexibleContexts -XTypeOperators

15+

16+Next, let's define our `TableType`s.

17+

1318>>> :{

1419type UsersTable =

1520 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

@@ -20,7 +25,7 @@ type UsersTable =

2025

2126>>> :{

2227type EmailsTable =

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

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

2429 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

2530 ] :=>

2631 '[ "id" ::: 'Def :=> 'NotNull 'PGint4

@@ -29,248 +34,293 @@ type EmailsTable =

2934 ]

3035:}

3136

37+Now we can define some `Migration`s to make our tables.

38+

3239>>> :{

3340let

34− makeUsers :: Migration IO '[] '["users" ::: 'Table UsersTable]

41+ makeUsers :: Migration Definition (Public '[]) '["public" ::: '["users" ::: 'Table UsersTable]]

3542 makeUsers = Migration

3643 { name = "make users table"

37− , up = void . define $

38− createTable #users

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− -- * Aligned lists

109− , AlignedList (..)

110− , single

111− -- * Migration table

143+ , Migratory (..)

144+ , Terminally (..)

145+ , terminally

146+ , pureMigration

112147 , MigrationsTable

113− , createMigrations

114− , insertMigration

115− , deleteMigration

116− , selectMigration

148+ , defaultMain

117149 ) where

118150

119151import Control.Category

120152import Control.Monad

121−import Control.Monad.Base

122−import Control.Monad.Trans.Control

123−import Data.Monoid

124−import Generics.SOP (K(..))

153+import Data.ByteString (ByteString)

154+import Data.Foldable (traverse_)

125155import Data.Function ((&))

156+import Data.List ((\\))

126157import Data.Text (Text)

127−import Prelude hiding (id, (.))

158+import Data.Time (UTCTime)

159+import Prelude hiding ((.), id)

160+import System.Environment

161+import UnliftIO (MonadIO (..))

162+

163+import qualified Data.Text.IO as Text (putStrLn)

164+import qualified Generics.SOP as SOP

165+import qualified GHC.Generics as GHC

128166

129−import Squeal.PostgreSQL

167+import Squeal.PostgreSQL.Alias

168+import Squeal.PostgreSQL.Binary

169+import Squeal.PostgreSQL.Definition

170+import Squeal.PostgreSQL.Definition.Table

171+import Squeal.PostgreSQL.Definition.Table.Constraint

172+import Squeal.PostgreSQL.Expression.Comparison

173+import Squeal.PostgreSQL.Expression.Parameter

174+import Squeal.PostgreSQL.Expression.Time

175+import Squeal.PostgreSQL.Expression.Type

176+import Squeal.PostgreSQL.List

177+import Squeal.PostgreSQL.Manipulation

178+import Squeal.PostgreSQL.PQ

179+import Squeal.PostgreSQL.Query

180+import Squeal.PostgreSQL.Schema

181+import Squeal.PostgreSQL.Transaction

130182

131−-- | A `Migration` should contain an inverse pair of

132−-- `up` and `down` instructions and a unique `name`.

133−data Migration io schema0 schema1 = Migration

183+-- | A `Migration` is a named "isomorphism" over a given category.

184+-- It should contain an inverse pair of `up` and `down`

185+-- instructions and a unique `name`.

186+data Migration p schemas0 schemas1 = Migration

134187 { name :: Text -- ^ The `name` of a `Migration`.

135188 -- Each `name` in a `Migration` should be unique.

136− , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.

137− , down :: PQ schema1 schema0 io () -- ^ The `down` instruction of a `Migration`.

189+ , up :: p schemas0 schemas1 -- ^ The `up` instruction of a `Migration`.

190+ , down :: p schemas1 schemas0 -- ^ The `down` instruction of a `Migration`.

191+ } deriving (GHC.Generic)

192+

193+{- |

194+A `Migratory` @p@ is a `Category` for which one can execute or rewind

195+a `Path` of `Migration`s over @p@. This includes the category of pure

196+SQL `Definition`s and the category of impure `Terminally` `PQ` `IO` actions.

197+-}

198+class Category p => Migratory p where

199+

200+ {- |

201+ Run a `Path` of `Migration`s.

202+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

203+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

204+ if not, `up` the `Migration` and insert its `name` in the `MigrationsTable`.

205+ -}

206+ migrateUp

207+ :: Path (Migration p) schemas0 schemas1

208+ -> PQ schemas0 schemas1 IO ()

209+

210+ {- |

211+ Rewind a `Path` of `Migration`s.

212+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

213+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

214+ if so, `down` the `Migration` and delete its `name` in the `MigrationsTable`.

215+ -}

216+ migrateDown

217+ :: Path (Migration p) schemas0 schemas1

218+ -> PQ schemas1 schemas0 IO ()

219+

220+instance Migratory Definition where

221+ migrateUp = migrateUp . cmap pureMigration

222+ migrateDown = migrateDown . cmap pureMigration

223+

224+{- | `Terminally` turns an indexed monad transformer and the monad it transforms

225+into a category by restricting the return type to @()@ and permuting the type variables.

226+This is similar to how applying a monad to @()@ yields a monoid.

227+Since a `Terminally` action has a trivial return value, the only reason

228+to run one is for the side effects, in particular database and other IO effects.

229+-}

230+newtype Terminally trans monad x0 x1 = Terminally

231+ { runTerminally :: trans x0 x1 monad () }

232+ deriving GHC.Generic

233+

234+instance

235+ ( IndexedMonadTransPQ trans

236+ , Monad monad

237+ , forall x0 x1. x0 ~ x1 => Monad (trans x0 x1 monad) )

238+ => Category (Terminally trans monad) where

239+ id = Terminally (return ())

240+ Terminally g . Terminally f = Terminally $ pqThen g f

241+

242+-- | `terminally` ignores the output of a computation, returning @()@ and

243+-- wrapping it up into a `Terminally`. You can lift an action in the base monad

244+-- by using @terminally . lift@.

245+terminally

246+ :: Functor (trans x0 x1 monad)

247+ => trans x0 x1 monad ignore

248+ -> Terminally trans monad x0 x1

249+terminally = Terminally . void

250+

251+-- | A `pureMigration` turns a `Migration` involving only pure SQL

252+-- `Definition`s into a `Migration` that may be combined with arbitrary `IO`.

253+pureMigration

254+ :: Migration Definition schemas0 schemas1

255+ -> Migration (Terminally PQ IO) schemas0 schemas1

256+pureMigration migration = Migration

257+ { name = name migration

258+ , up = terminally . define $ up migration

259+ , down = terminally . define $ down migration

138260 }

139261

140−-- | An `AlignedList` is a type-aligned list or free category.

141−data AlignedList p x0 x1 where

142− Done :: AlignedList p x x

143− (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2

144−infixr 7 :>>

145−instance Category (AlignedList p) where

146− id = Done

147− (.) list = \case

148− Done -> list

149− step :>> steps -> step :>> (steps >>> list)

150−

151−-- | A `single` step.

152−single :: p x0 x1 -> AlignedList p x0 x1

153−single step = step :>> Done

154−

155−-- | Run `Migration`s by creating the `MigrationsTable`

156−-- if it does not exist and then in a transaction, for each each `Migration`

157−-- query to see if the `Migration` is executed. If not, then

158−-- execute the `Migration` and insert its row in the `MigrationsTable`.

159−migrateUp

160− :: MonadBaseControl IO io

161− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run

162− -> PQ

163− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

164− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

165− io ()

166−migrateUp migration =

167− define createMigrations

168− & pqBind okResult

169− & pqThen (transactionallySchema_ (upMigrations migration))

170− where

262+instance Migratory (Terminally PQ IO) where

171263

172− upMigrations

173− :: MonadBaseControl IO io

174− => AlignedList (Migration io) schema0 schema1

175− -> PQ

176− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

177− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

178− io ()

179− upMigrations = \case

180− Done -> return ()

181− step :>> steps -> upMigration step & pqThen (upMigrations steps)

182−

183− upMigration

184− :: MonadBase IO io

185− => Migration io schema0 schema1 -> PQ

186− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

187− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

188− io ()

189− upMigration step =

190− queryExecuted step

191− & pqBind (\ executed ->

192− if executed == 1 -- up step has already been executed

193− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

194− else

195− pqEmbed (up step) -- safely switch schemas

196− & pqThen (manipulateParams insertMigration (Only (name step)))

197− -- insert execution record

198− & pqBind okResult)

199−

200− queryExecuted

201− :: MonadBase IO io

202− => Migration io schema0 schema1 -> PQ

203− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

204− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

205− io Row

206− queryExecuted step = do

207− result <- runQueryParams selectMigration (Only (name step))

208− okResult result

209− ntuples result

210−

211−-- | Rewind `Migration`s by creating the `MigrationsTable`

212−-- if it does not exist and then in a transaction, for each each `Migration`

213−-- query to see if the `Migration` is executed. If it is, then

214−-- rewind the `Migration` and delete its row in the `MigrationsTable`.

215−migrateDown

216− :: MonadBaseControl IO io

217− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind

218− -> PQ

219− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

220− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

221− io ()

222−migrateDown migrations =

223− define createMigrations

224− & pqBind okResult

225− & pqThen (transactionallySchema_ (downMigrations migrations))

226− where

264+ migrateUp migration = unsafePQ . transactionally_ $ do

265+ define createMigrations

266+ upMigrations migration

267+

268+ where

269+

270+ upMigrations

271+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

272+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

273+ upMigrations = \case

274+ Done -> return ()

275+ step :>> steps -> upMigration step >> upMigrations steps

276+

277+ upMigration

278+ :: Migration (Terminally PQ IO) schemas0 schemas1

279+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

280+ upMigration step = do

281+ executed <- queryExecuted step

282+ unless (executed == 1) $ do

283+ unsafePQ . runTerminally $ up step

284+ manipulateParams_ insertMigration (Only (name step))

285+

286+ queryExecuted

287+ :: Migration (Terminally PQ IO) schemas0 schemas1

288+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

289+ queryExecuted step = do

290+ result <- runQueryParams selectMigration (Only (name step))

291+ ntuples result

292+

293+ migrateDown migrations = unsafePQ . transactionally_ $ do

294+ define createMigrations

295+ downMigrations migrations

296+

297+ where

227298

228− downMigrations

229− :: MonadBaseControl IO io

230− => AlignedList (Migration io) schema0 schema1 -> PQ

231− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

232− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

233− io ()

234− downMigrations = \case

235− Done -> return ()

236− step :>> steps -> downMigrations steps & pqThen (downMigration step)

237−

238− downMigration

239− :: MonadBase IO io

240− => Migration io schema0 schema1 -> PQ

241− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

242− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

243− io ()

244− downMigration step =

245− queryExecuted step

246− & pqBind (\ executed ->

247− if executed == 0 -- up step has not been executed

248− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

249− else

250− pqEmbed (down step) -- safely switch schemas

251− & pqThen (manipulateParams deleteMigration (Only (name step)))

252− -- delete execution record

253− & pqBind okResult)

254−

255− queryExecuted

256− :: MonadBase IO io

257− => Migration io schema0 schema1 -> PQ

258− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

259− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

260− io Row

261− queryExecuted step = do

262− result <- runQueryParams selectMigration (Only (name step))

263− okResult result

264− ntuples result

265−

266−okResult :: MonadBase IO io => K Result results -> PQ schema schema io ()

267−okResult result = do

268− status <- resultStatus result

269− when (not (status `elem` [CommandOk, TuplesOk])) $ do

270− errorMessageMaybe <- resultErrorMessage result

271− case errorMessageMaybe of

272− Nothing -> error "migrateDown: unknown error"

273− Just msg -> error ("migrationDown: " <> show msg)

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

274324

275325-- | The `TableType` for a Squeal migration.

276326type MigrationsTable =

@@ -279,10 +329,19 @@ type MigrationsTable =

279329 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

280330 ]

281331

332+data MigrationRow =

333+ MigrationRow { migrationName :: Text

334+ , migrationTime :: UTCTime }

335+ deriving (GHC.Generic, Show)

336+

337+instance SOP.Generic MigrationRow

338+instance SOP.HasDatatypeInfo MigrationRow

339+

340+type MigrationsSchema = '["schema_migrations" ::: 'Table MigrationsTable]

341+type MigrationsSchemas = Public MigrationsSchema

342+

282343-- | Creates a `MigrationsTable` if it does not already exist.

283−createMigrations

284− :: Has "schema_migrations" schema ('Table MigrationsTable)

285− => Definition schema schema

344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas

286345createMigrations =

287346 createTableIfNotExists #schema_migrations

288347 ( (text & notNullable) `as` #name :*

@@ -290,27 +349,100 @@ createMigrations =

290349 `as` #executed_at )

291350 ( unique #name `as` #migrations_unique_name )

292351

293−-- | Inserts a `Migration` into the `MigrationsTable`

294−insertMigration

295− :: Has "schema_migrations" schema ('Table MigrationsTable)

296− => Manipulation schema '[ 'NotNull 'PGtext] '[]

297−insertMigration = insertRow_ #schema_migrations

298− ( Set (param @1) `as` #name :*

299− Default `as` #executed_at )

300−

301−-- | Deletes a `Migration` from the `MigrationsTable`

302−deleteMigration

303− :: Has "schema_migrations" schema ('Table MigrationsTable)

304− => 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) ()

305361deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

306362

307363-- | Selects a `Migration` from the `MigrationsTable`, returning

308−-- the time at which it was executed.

364+-- the time at which it was inserted.

309365selectMigration

310− :: Has "schema_migrations" schema ('Table MigrationsTable)

311− => Query schema '[ 'NotNull 'PGtext ]

312− '[ "executed_at" ::: 'NotNull 'PGtimestamptz ]

313−selectMigration = select

314− (#executed_at `as` #executed_at)

315− ( from (table (#schema_migrations `as` #m))

316− & where_ (#name .== param @1))

366+ :: Query_ MigrationsSchemas (Only Text) (Only UTCTime)

367+selectMigration = select_ (#executed_at `as` #fromOnly)

368+ $ from (table (#schema_migrations))

369+ & where_ (#name .== param @1)

370+

371+selectMigrations :: Query_ MigrationsSchemas () MigrationRow

372+selectMigrations = select_

373+ (#name `as` #migrationName :* #executed_at `as` #migrationTime)

374+ (from (table #schema_migrations))

375+

376+data MigrateCommand

377+ = MigrateStatus

378+ | MigrateUp

379+ | MigrateDown deriving (GHC.Generic, Show)

380+

381+{- | `defaultMain` creates a simple executable

382+from a connection string and a list of `Migration`s. -}

383+defaultMain

384+ :: Migratory p

385+ => ByteString

386+ -- ^ connection string

387+ -> Path (Migration p) db0 db1

388+ -- ^ migrations

389+ -> IO ()

390+defaultMain connectTo migrations = do

391+ command <- readCommandFromArgs

392+ maybe (pure ()) performCommand command

393+

394+ where

395+

396+ performCommand :: MigrateCommand -> IO ()

397+ performCommand = \case

398+ MigrateStatus -> withConnection connectTo $

399+ suppressNotices >> migrateStatus

400+ MigrateUp -> withConnection connectTo $

401+ suppressNotices & pqThen (migrateUp migrations) & pqThen migrateStatus

402+ MigrateDown -> withConnection connectTo $

403+ suppressNotices & pqThen (migrateDown migrations) & pqThen migrateStatus

404+

405+ migrateStatus :: PQ schema schema IO ()

406+ migrateStatus = unsafePQ $ do

407+ runNames <- getRunMigrationNames

408+ let names = ctoList name migrations

409+ unrunNames = names \\ runNames

410+ liftIO $ displayRunned runNames >> displayUnrunned unrunNames

411+

412+ suppressNotices :: PQ schema schema IO ()

413+ suppressNotices = manipulate_ $

414+ UnsafeManipulation "SET client_min_messages TO WARNING;"

415+

416+ readCommandFromArgs :: IO (Maybe MigrateCommand)

417+ readCommandFromArgs = getArgs >>= \case

418+ ["migrate"] -> pure . Just $ MigrateUp

419+ ["rollback"] -> pure . Just $ MigrateDown

420+ ["status"] -> pure . Just $ MigrateStatus

421+ args -> displayUsage args >> pure Nothing

422+

423+ displayUsage :: [String] -> IO ()

424+ displayUsage args = do

425+ putStrLn $ "Invalid command: \"" <> unwords args <> "\". Use:"

426+ putStrLn "migrate to run all available migrations"

427+ putStrLn "rollback to rollback all available migrations"

428+ putStrLn "status to display migrations run and migrations left to run"

429+

430+ getRunMigrationNames :: (MonadIO m) => PQ db0 db0 m [Text]

431+ getRunMigrationNames =

432+ fmap migrationName <$> (unsafePQ (define createMigrations & pqThen (runQuery selectMigrations)) >>= getRows)

433+

434+ displayListOfNames :: [Text] -> IO ()

435+ displayListOfNames [] = Text.putStrLn " None"

436+ displayListOfNames xs =

437+ let singleName n = Text.putStrLn $ " - " <> n

438+ in traverse_ singleName xs

439+

440+ displayUnrunned :: [Text] -> IO ()

441+ displayUnrunned unrunned =

442+ Text.putStrLn "Migrations left to run:"

443+ >> displayListOfNames unrunned

444+

445+ displayRunned :: [Text] -> IO ()

446+ displayRunned runned =

447+ Text.putStrLn "Migrations already run:"

448+ >> displayListOfNames runned

squeal-postgresql/src/Squeal/PostgreSQL/PG.hsnew file+388

@@ -0,0 +1,388 @@

1+{-|

2+Module: Squeal.PostgreSQL.PG

3+Description: Embedding of Haskell types into Postgres's type system

4+Copyright: (c) Eitan Chatav, 2010

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+`Squeal.PostgreSQL.PG` provides type families for turning Haskell

9+`Type`s into corresponding Postgres types.

10+-}

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DeriveAnyClass

14+ , DeriveFoldable

15+ , DeriveFunctor

16+ , DeriveGeneric

17+ , DeriveTraversable

18+ , DerivingStrategies

19+ , DefaultSignatures

20+ , FlexibleContexts

21+ , FlexibleInstances

22+ , FunctionalDependencies

23+ , GADTs

24+ , LambdaCase

25+ , MultiParamTypeClasses

26+ , OverloadedStrings

27+ , ScopedTypeVariables

28+ , TypeApplications

29+ , TypeFamilies

30+ , TypeInType

31+ , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

34+#-}

35+

36+module Squeal.PostgreSQL.PG

37+ ( -- * PG embeddings

38+ PG

39+ , NullPG

40+ , TuplePG

41+ , RowPG

42+ -- * Storage newtypes

43+ , Money (..)

44+ , Json (..)

45+ , Jsonb (..)

46+ , Composite (..)

47+ , Enumerated (..)

48+ , VarArray (..)

49+ , FixArray (..)

50+ , LibPQ.Oid (..)

51+ -- * Type families

52+ , LabelsPG

53+ , DimPG

54+ , FixPG

55+ , TupleOf

56+ , TupleCodeOf

57+ , RowOf

58+ , ConstructorsOf

59+ , ConstructorNameOf

60+ , ConstructorNamesOf

61+ ) where

62+

63+import Data.Aeson (Value)

64+import Data.Kind (Type)

65+import Data.Int (Int16, Int32, Int64)

66+import Data.Scientific (Scientific)

67+import Data.Time (Day, DiffTime, LocalTime, TimeOfDay, TimeZone, UTCTime)

68+import Data.Vector (Vector)

69+import Data.UUID.Types (UUID)

70+import GHC.TypeLits

71+import Network.IP.Addr (NetAddr, IP)

72+

73+import qualified Data.ByteString.Lazy as Lazy (ByteString)

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

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

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

77+import qualified Database.PostgreSQL.LibPQ as LibPQ

78+import qualified GHC.Generics as GHC

79+import qualified Generics.SOP as SOP

80+import qualified Generics.SOP.Record as SOP

81+import qualified Generics.SOP.Type.Metadata as Type

82+

83+import Squeal.PostgreSQL.Alias

84+import Squeal.PostgreSQL.Schema

85+

86+-- $setup

87+-- >>> import Squeal.PostgreSQL

88+-- >>> import Data.Text (Text)

89+

90+{- | The `PG` type family embeds a subset of Haskell types

91+as Postgres types. As an open type family, `PG` is extensible.

92+

93+>>> :kind! PG LocalTime

94+PG LocalTime :: PGType

95+= 'PGtimestamp

96+

97+>>> newtype MyDouble = My Double

98+>>> :set -XTypeFamilies

99+>>> type instance PG MyDouble = 'PGfloat8

100+-}

101+type family PG (hask :: Type) :: PGType

102+-- | `PGbool`

103+type instance PG Bool = 'PGbool

104+-- | `PGint2`

105+type instance PG Int16 = 'PGint2

106+-- | `PGint4`

107+type instance PG Int32 = 'PGint4

108+-- | `PGint8`

109+type instance PG Int64 = 'PGint8

110+-- | `PGint2`

111+type instance PG LibPQ.Oid = 'PGoid

112+-- | `PGnumeric`

113+type instance PG Scientific = 'PGnumeric

114+-- | `PGfloat4`

115+type instance PG Float = 'PGfloat4

116+-- | `PGfloat8`

117+type instance PG Double = 'PGfloat8

118+-- | `PGchar` @1@

119+type instance PG Char = 'PGchar 1

120+-- | `PGtext`

121+type instance PG Strict.Text = 'PGtext

122+-- | `PGtext`

123+type instance PG Lazy.Text = 'PGtext

124+-- | `PGtext`

125+type instance PG String = 'PGtext

126+-- | `PGbytea`

127+type instance PG Strict.ByteString = 'PGbytea

128+-- | `PGbytea`

129+type instance PG Lazy.ByteString = 'PGbytea

130+-- | `PGtimestamp`

131+type instance PG LocalTime = 'PGtimestamp

132+-- | `PGtimestamptz`

133+type instance PG UTCTime = 'PGtimestamptz

134+-- | `PGdate`

135+type instance PG Day = 'PGdate

136+-- | `PGtime`

137+type instance PG TimeOfDay = 'PGtime

138+-- | `PGtimetz`

139+type instance PG (TimeOfDay, TimeZone) = 'PGtimetz

140+-- | `PGinterval`

141+type instance PG DiffTime = 'PGinterval

142+-- | `PGuuid`

143+type instance PG UUID = 'PGuuid

144+-- | `PGinet`

145+type instance PG (NetAddr IP) = 'PGinet

146+-- | `PGjson`

147+type instance PG Value = 'PGjson

148+

149+{-| The `LabelsPG` type family calculates the constructors of a

150+Haskell enum type.

151+

152+>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

153+>>> instance SOP.Generic Schwarma

154+>>> instance SOP.HasDatatypeInfo Schwarma

155+>>> :kind! LabelsPG Schwarma

156+LabelsPG Schwarma :: [Type.ConstructorName]

157+= '["Beef", "Lamb", "Chicken"]

158+-}

159+type family LabelsPG (hask :: Type) :: [Type.ConstructorName] where

160+ LabelsPG hask =

161+ ConstructorNamesOf (ConstructorsOf (SOP.DatatypeInfoOf hask))

162+

163+{- |

164+`RowPG` turns a Haskell `Type` into a `RowType`.

165+

166+`RowPG` may be applied to normal Haskell record types provided they

167+have `SOP.Generic` and `SOP.HasDatatypeInfo` instances;

168+

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

170+>>> instance SOP.Generic Person

171+>>> instance SOP.HasDatatypeInfo Person

172+>>> :kind! RowPG Person

173+RowPG Person :: [(Symbol, NullityType)]

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

175+-}

176+type family RowPG (hask :: Type) :: RowType where

177+ RowPG hask = RowOf (SOP.RecordCodeOf hask)

178+

179+-- | `RowOf` applies `NullPG` to the fields of a list.

180+type family RowOf (record :: [(Symbol, Type)]) :: RowType where

181+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': col4 ::: ty4 ': record) =

182+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': col4 ::: NullPG ty4 ': RowOf record

183+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': record) =

184+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': RowOf record

185+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': record) =

186+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': RowOf record

187+ RowOf (col ::: ty ': col1 ::: ty1 ': record) =

188+ col ::: NullPG ty ': col1::: NullPG ty1 ': RowOf record

189+ RowOf (col ::: ty ': record) = col ::: NullPG ty ': RowOf record

190+ RowOf '[] = '[]

191+

192+{- | `NullPG` turns a Haskell type into a `NullityType`.

193+

194+>>> :kind! NullPG Double

195+NullPG Double :: NullityType

196+= 'NotNull 'PGfloat8

197+>>> :kind! NullPG (Maybe Double)

198+NullPG (Maybe Double) :: NullityType

199+= 'Null 'PGfloat8

200+-}

201+type family NullPG (hask :: Type) :: NullityType where

202+ NullPG (Maybe hask) = 'Null (PG hask)

203+ NullPG hask = 'NotNull (PG hask)

204+

205+{- | `TuplePG` turns a Haskell tuple type (including record types) into

206+the corresponding list of `NullityType`s.

207+

208+>>> :kind! TuplePG (Double, Maybe Char)

209+TuplePG (Double, Maybe Char) :: [NullityType]

210+= '[ 'NotNull 'PGfloat8, 'Null ('PGchar 1)]

211+-}

212+type family TuplePG (hask :: Type) :: [NullityType] where

213+ TuplePG hask = TupleOf (TupleCodeOf hask (SOP.Code hask))

214+

215+-- | `TupleOf` turns a list of Haskell `Type`s into a list of `NullityType`s.

216+type family TupleOf (tuple :: [Type]) :: [NullityType] where

217+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': hask5 ': tuple) =

218+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': NullPG hask5 ': TupleOf tuple

219+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': tuple) =

220+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': TupleOf tuple

221+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': tuple) =

222+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': TupleOf tuple

223+ TupleOf (hask ': hask1 ': hask2 ': tuple) =

224+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': TupleOf tuple

225+ TupleOf (hask ': hask1 ': tuple) = NullPG hask ': NullPG hask1 ': TupleOf tuple

226+ TupleOf (hask ': tuple) = NullPG hask ': TupleOf tuple

227+ TupleOf '[] = '[]

228+

229+-- | `TupleCodeOf` takes the `SOP.Code` of a haskell `Type`

230+-- and if it's a simple product returns it, otherwise giving a `TypeError`.

231+type family TupleCodeOf (hask :: Type) (code :: [[Type]]) :: [Type] where

232+ TupleCodeOf hask '[tuple] = tuple

233+ TupleCodeOf hask '[] =

234+ TypeError

235+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

236+ ':$$: 'Text "It is a void type with no constructors."

237+ )

238+ TupleCodeOf hask (_ ': _ ': _) =

239+ TypeError

240+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

241+ ':$$: 'Text "It is a sum type with more than one constructor."

242+ )

243+

244+-- | Calculates constructors of a datatype.

245+type family ConstructorsOf (datatype :: Type.DatatypeInfo)

246+ :: [Type.ConstructorInfo] where

247+ ConstructorsOf ('Type.ADT _module _datatype constructors) =

248+ constructors

249+ ConstructorsOf ('Type.Newtype _module _datatype constructor) =

250+ '[constructor]

251+

252+-- | Calculates the name of a nullary constructor, otherwise

253+-- generates a type error.

254+type family ConstructorNameOf (constructor :: Type.ConstructorInfo)

255+ :: Type.ConstructorName where

256+ ConstructorNameOf ('Type.Constructor name) = name

257+ ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

258+ ('Text "ConstructorNameOf error: non-nullary constructor "

259+ ':<>: 'Text name)

260+ ConstructorNameOf ('Type.Record name _fields) = TypeError

261+ ('Text "ConstructorNameOf error: non-nullary constructor "

262+ ':<>: 'Text name)

263+

264+-- | Calculate the names of nullary constructors.

265+type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

266+ :: [Type.ConstructorName] where

267+ ConstructorNamesOf '[] = '[]

268+ ConstructorNamesOf (constructor ': constructors) =

269+ ConstructorNameOf constructor ': ConstructorNamesOf constructors

270+

271+-- | `DimPG` turns Haskell nested homogeneous tuples into a list of lengths.

272+type family DimPG (hask :: Type) :: [Nat] where

273+ DimPG (x,x) = 2 ': DimPG x

274+ DimPG (x,x,x) = 3 ': DimPG x

275+ DimPG (x,x,x,x) = 4 ': DimPG x

276+ DimPG (x,x,x,x,x) = 5 ': DimPG x

277+ DimPG (x,x,x,x,x,x) = 6 ': DimPG x

278+ DimPG (x,x,x,x,x,x,x) = 7 ': DimPG x

279+ DimPG (x,x,x,x,x,x,x,x) = 8 ': DimPG x

280+ DimPG (x,x,x,x,x,x,x,x,x) = 9 ': DimPG x

281+ DimPG (x,x,x,x,x,x,x,x,x,x) = 10 ': DimPG x

282+ DimPG x = '[]

283+

284+-- | `FixPG` extracts `NullPG` of the base type of nested homogeneous tuples.

285+type family FixPG (hask :: Type) :: NullityType where

286+ FixPG (x,x) = FixPG x

287+ FixPG (x,x,x) = FixPG x

288+ FixPG (x,x,x,x) = FixPG x

289+ FixPG (x,x,x,x,x) = FixPG x

290+ FixPG (x,x,x,x,x,x) = FixPG x

291+ FixPG (x,x,x,x,x,x,x) = FixPG x

292+ FixPG (x,x,x,x,x,x,x,x) = FixPG x

293+ FixPG (x,x,x,x,x,x,x,x,x) = FixPG x

294+ FixPG (x,x,x,x,x,x,x,x,x,x) = FixPG x

295+ FixPG (x,x,x,x,x,x,x,x,x,x,x) = FixPG x

296+ FixPG x = NullPG x

297+

298+{- | The `Money` newtype stores a monetary value in terms

299+of the number of cents, i.e. @$2,000.20@ would be expressed as

300+@Money { cents = 200020 }@.

301+

302+>>> import Control.Monad (void)

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

304+>>> import Squeal.PostgreSQL

305+>>> :{

306+let

307+ roundTrip :: Query_ (Public '[]) (Only Money) (Only Money)

308+ roundTrip = values_ $ parameter @1 money `as` #fromOnly

309+:}

310+

311+>>> let input = Only (Money 20020)

312+

313+>>> :{

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

315+ result <- runQueryParams roundTrip input

316+ Just output <- firstRow result

317+ liftIO . print $ input == output

318+:}

319+True

320+-}

321+newtype Money = Money { cents :: Int64 }

322+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

323+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

324+-- | `PGmoney`

325+type instance PG Money = 'PGmoney

326+

327+{- | The `Json` newtype is an indication that the Haskell

328+type it's applied to should be stored as a `PGjson`.

329+-}

330+newtype Json hask = Json {getJson :: hask}

331+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

332+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

333+-- | `PGjson`

334+type instance PG (Json hask) = 'PGjson

335+

336+{- | The `Jsonb` newtype is an indication that the Haskell

337+type it's applied to should be stored as a `PGjsonb`.

338+-}

339+newtype Jsonb hask = Jsonb {getJsonb :: hask}

340+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

341+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

342+-- | `PGjsonb`

343+type instance PG (Jsonb hask) = 'PGjsonb

344+

345+{- | The `Composite` newtype is an indication that the Haskell

346+type it's applied to should be stored as a `PGcomposite`.

347+-}

348+newtype Composite record = Composite {getComposite :: record}

349+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

350+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

351+-- | `PGcomposite` @(@`RowPG` @hask)@

352+type instance PG (Composite hask) = 'PGcomposite (RowPG hask)

353+

354+{- | The `Enumerated` newtype is an indication that the Haskell

355+type it's applied to should be stored as a `PGenum`.

356+-}

357+newtype Enumerated enum = Enumerated {getEnumerated :: enum}

358+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

359+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

360+-- | `PGenum` @(@`LabelsPG` @hask)@

361+type instance PG (Enumerated hask) = 'PGenum (LabelsPG hask)

362+

363+{- | The `VarArray` newtype is an indication that the Haskell

364+type it's applied to should be stored as a `PGvararray`.

365+

366+>>> :kind! PG (VarArray (Vector Double))

367+PG (VarArray (Vector Double)) :: PGType

368+= 'PGvararray ('NotNull 'PGfloat8)

369+-}

370+newtype VarArray arr = VarArray {getVarArray :: arr}

371+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

372+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

373+-- | `PGvararray` @(@`NullPG` @hask)@

374+type instance PG (VarArray (Vector hask)) = 'PGvararray (NullPG hask)

375+type instance PG (VarArray [hask]) = 'PGvararray (NullPG hask)

376+

377+{- | The `FixArray` newtype is an indication that the Haskell

378+type it's applied to should be stored as a `PGfixarray`.

379+

380+>>> :kind! PG (FixArray ((Double, Double), (Double, Double)))

381+PG (FixArray ((Double, Double), (Double, Double))) :: PGType

382+= 'PGfixarray '[2, 2] ('NotNull 'PGfloat8)

383+-}

384+newtype FixArray arr = FixArray {getFixArray :: arr}

385+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

386+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

387+-- | `PGfixarray` @(@`DimPG` @hask) (@`FixPG` @hask)@

388+type instance PG (FixArray hask) = 'PGfixarray (DimPG hask) (FixPG hask)

squeal-postgresql/src/Squeal/PostgreSQL/PQ.hs+272−209

@@ -6,12 +6,12 @@ Maintainer: eitan@morphism.tech

66Stability: experimental

88This module is where Squeal commands actually get executed by

9−`LibPQ`. It containts two typeclasses, `IndexedMonadTransPQ` for executing

9+`Database.PostgreSQL.LibPQ`. It containts two typeclasses, `IndexedMonadTransPQ` for executing

1010a `Definition` and `MonadPQ` for executing a `Manipulation` or `Query`,

1111and a `PQ` type with instances for them.

1212

1313Using Squeal in your application will come down to defining

14−the @schema@ of your database and including @PQ schema schema@ in your

14+the @schemas@ of your database and including @PQ schemas schemas@ in your

1515application's monad transformer stack, giving it an instance of `MonadPQ`.

1616

1717This module also provides functions for retrieving rows from the `LibPQ.Result`

@@ -24,6 +24,7 @@ of executing Squeal commands.

2424 , FunctionalDependencies

2525 , FlexibleContexts

2626 , FlexibleInstances

27+ , InstanceSigs

2728 , OverloadedStrings

2829 , RankNTypes

2930 , ScopedTypeVariables

@@ -48,9 +49,7 @@ module Squeal.PostgreSQL.PQ

4849 , evalPQ

4950 , IndexedMonadTransPQ (..)

5051 , MonadPQ (..)

51− , PQRun

52− , pqliftWith

53− -- * Result

52+ -- * Results

5453 , LibPQ.Result

5554 , LibPQ.Row

5655 , ntuples

@@ -63,25 +62,32 @@ module Squeal.PostgreSQL.PQ

6362 , resultStatus

6463 , resultErrorMessage

6564 , resultErrorCode

65+ -- * Exceptions

6666 , SquealException (..)

67+ , PQState (..)

68+ , okResult

69+ , catchSqueal

70+ , handleSqueal

71+ , trySqueal

6772 ) where

6873

69−import Control.Exception.Lifted

70−import Control.Monad.Base

74+import Control.Exception (Exception, throw)

7175import Control.Monad.Except

7276import Control.Monad.Morph

73−import Control.Monad.Trans.Control

77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)

7478import Data.ByteString (ByteString)

7579import Data.Foldable

7680import Data.Function ((&))

81+import Data.Functor ((<&>))

7782import Data.Kind

78−import Data.Monoid

79−import Data.Text (unpack)

83+import Data.Text (pack, Text)

8084import Data.Traversable

8185import Generics.SOP

8286import PostgreSQL.Binary.Encoding (encodingBytes)

8387

88+import qualified Control.Monad.Fail as Fail

8489import qualified Database.PostgreSQL.LibPQ as LibPQ

90+import qualified PostgreSQL.Binary.Encoding as Encoding

8591

8692import Squeal.PostgreSQL.Binary

8793import Squeal.PostgreSQL.Definition

@@ -94,7 +100,6 @@ import Control.Monad.Trans.Identity

94100import Control.Monad.Trans.Reader

95101import Control.Monad.Trans.Maybe

96102import Control.Monad.Trans.Cont

97−import Control.Monad.Trans.List

98103

99104import qualified Control.Monad.Trans.State.Lazy as Lazy

100105import qualified Control.Monad.Trans.State.Strict as Strict

@@ -103,6 +108,9 @@ import qualified Control.Monad.Trans.Writer.Strict as Strict

103108import qualified Control.Monad.Trans.RWS.Lazy as Lazy

104109import qualified Control.Monad.Trans.RWS.Strict as Strict

105110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

106114{- | Makes a new connection to the database server.

107115

108116This function opens a new database connection using the parameters taken

@@ -129,22 +137,22 @@ Note that, for now, squeal doesn't offer any protection from connecting

129137with the wrong schema!

130138-}

131139connectdb

132− :: forall schema io

133− . MonadBase IO io

140+ :: forall schemas io

141+ . MonadIO io

134142 => ByteString -- ^ conninfo

135− -> io (K LibPQ.Connection schema)

136−connectdb = fmap K . liftBase . LibPQ.connectdb

143+ -> io (K LibPQ.Connection schemas)

144+connectdb = fmap K . liftIO . LibPQ.connectdb

137145

138146-- | Closes the connection to the server.

139−finish :: MonadBase IO io => K LibPQ.Connection schema -> io ()

140−finish = liftBase . LibPQ.finish . unK

147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()

148+finish = liftIO . LibPQ.finish . unK

141149

142150-- | Do `connectdb` and `finish` before and after a computation.

143151withConnection

144− :: forall schema0 schema1 io x

145− . MonadBaseControl IO io

152+ :: forall schemas0 schemas1 io x

153+ . MonadUnliftIO io

146154 => ByteString

147− -> PQ schema0 schema1 io x

155+ -> PQ schemas0 schemas1 io x

148156 -> io x

149157withConnection connString action = do

150158 K x <- bracket (connectdb connString) finish (unPQ action)

@@ -152,47 +160,47 @@ withConnection connString action = do

152160

153161-- | Safely `lowerConnection` to a smaller schema.

154162lowerConnection

155− :: K LibPQ.Connection (table ': schema)

156− -> K LibPQ.Connection schema

163+ :: K LibPQ.Connection (schema ': schemas)

164+ -> K LibPQ.Connection schemas

157165lowerConnection (K conn) = K conn

158166

159167-- | We keep track of the schema via an Atkey indexed state monad transformer,

160168-- `PQ`.

161169newtype PQ

162− (schema0 :: SchemaType)

163− (schema1 :: SchemaType)

170+ (schemas0 :: SchemasType)

171+ (schemas1 :: SchemasType)

164172 (m :: Type -> Type)

165173 (x :: Type) =

166− PQ { unPQ :: K LibPQ.Connection schema0 -> m (K x schema1) }

174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }

167175

168−instance Monad m => Functor (PQ schema0 schema1 m) where

176+instance Monad m => Functor (PQ schemas0 schemas1 m) where

169177 fmap f (PQ pq) = PQ $ \ conn -> do

170178 K x <- pq conn

171179 return $ K (f x)

172180

173−-- | Run a `PQ` and keep the result and the `Connection`.

181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.

174182runPQ

175183 :: Functor m

176− => PQ schema0 schema1 m x

177− -> K LibPQ.Connection schema0

178− -> m (x, K LibPQ.Connection schema1)

184+ => PQ schemas0 schemas1 m x

185+ -> K LibPQ.Connection schemas0

186+ -> m (x, K LibPQ.Connection schemas1)

179187runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

180188 -- K x <- pq conn

181189 -- return (x, K (unK conn))

182190

183−-- | Execute a `PQ` and discard the result but keep the `Connection`.

191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.

184192execPQ

185193 :: Functor m

186− => PQ schema0 schema1 m x

187− -> K LibPQ.Connection schema0

188− -> m (K LibPQ.Connection schema1)

194+ => PQ schemas0 schemas1 m x

195+ -> K LibPQ.Connection schemas0

196+ -> m (K LibPQ.Connection schemas1)

189197execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

190198

191−-- | Evaluate a `PQ` and discard the `Connection` but keep the result.

199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.

192200evalPQ

193201 :: Functor m

194− => PQ schema0 schema1 m x

195− -> K LibPQ.Connection schema0

202+ => PQ schemas0 schemas1 m x

203+ -> K LibPQ.Connection schemas0

196204 -> m x

197205evalPQ (PQ pq) conn = unK <$> pq conn

198206

@@ -200,60 +208,56 @@ evalPQ (PQ pq) conn = unK <$> pq conn

200208-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

201209-- An indexed monad transformer transforms a `Monad` into an indexed monad.

202210-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

203−-- support running `Definition`s using `define` and embedding a computation

204−-- in a larger schema using `pqEmbed`.

211+-- support running `Definition`s using `define`.

205212class IndexedMonadTransPQ pq where

206213

207214 -- | indexed analog of `<*>`

208215 pqAp

209216 :: Monad m

210− => pq schema0 schema1 m (x -> y)

211− -> pq schema1 schema2 m x

212− -> pq schema0 schema2 m y

217+ => pq schemas0 schemas1 m (x -> y)

218+ -> pq schemas1 schemas2 m x

219+ -> pq schemas0 schemas2 m y

213220

214221 -- | indexed analog of `join`

215222 pqJoin

216223 :: Monad m

217− => pq schema0 schema1 m (pq schema1 schema2 m y)

218− -> pq schema0 schema2 m y

224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)

225+ -> pq schemas0 schemas2 m y

219226 pqJoin pq = pq & pqBind id

220227

221228 -- | indexed analog of `=<<`

222229 pqBind

223230 :: Monad m

224− => (x -> pq schema1 schema2 m y)

225− -> pq schema0 schema1 m x

226− -> pq schema0 schema2 m y

231+ => (x -> pq schemas1 schemas2 m y)

232+ -> pq schemas0 schemas1 m x

233+ -> pq schemas0 schemas2 m y

227234

228235 -- | indexed analog of flipped `>>`

229236 pqThen

230237 :: Monad m

231− => pq schema1 schema2 m y

232− -> pq schema0 schema1 m x

233− -> pq schema0 schema2 m y

238+ => pq schemas1 schemas2 m y

239+ -> pq schemas0 schemas1 m x

240+ -> pq schemas0 schemas2 m y

234241 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

235242

236243 -- | indexed analog of `<=<`

237244 pqAndThen

238245 :: Monad m

239− => (y -> pq schema1 schema2 m z)

240− -> (x -> pq schema0 schema1 m y)

241− -> 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

242249 pqAndThen g f x = pqBind g (f x)

243250

244− -- | Safely embed a computation in a larger schema.

245− pqEmbed

246− :: Monad m

247− => pq schema0 schema1 m x

248− -> pq (table ': schema0) (table : schema1) m x

249−

250− -- | Run a `Definition` with `LibPQ.exec`, we expect that libpq obeys the law

251+ -- | Run a `Definition` with `LibPQ.exec`.

251252 --

252− -- @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)@

253257 define

254− :: MonadBase IO io

255− => Definition schema0 schema1

256− -> pq schema0 schema1 io (K LibPQ.Result '[])

258+ :: MonadIO io

259+ => Definition schemas0 schemas1

260+ -> pq schemas0 schemas1 io ()

257261

258262instance IndexedMonadTransPQ PQ where

259263

@@ -266,26 +270,26 @@ instance IndexedMonadTransPQ PQ where

266270 K x' <- x conn

267271 unPQ (f x') (K (unK conn))

268272

269− pqEmbed (PQ pq) = PQ $ \ (K conn) -> do

270− K x <- pq (K conn)

271− return $ K x

272−

273273 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

274− resultMaybe <- liftBase $ LibPQ.exec conn q

274+ resultMaybe <- liftIO $ LibPQ.exec conn q

275275 case resultMaybe of

276− Nothing -> error

276+ Nothing -> throw $ ResultException

277277 "define: LibPQ.exec returned no results"

278− Just result -> return $ K (K result)

278+ Just result -> K <$> okResult_ result

279279

280−{- | `MonadPQ` is an `mtl` style constraint, similar to

281−`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

282282

283283* `manipulateParams` runs a `Manipulation` with params from a type

284284 with a `ToParams` constraint. It calls `LibPQ.execParams` and

285285 doesn't afraid of anything.

286286

287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.

288+

287289* `manipulate` is like `manipulateParams` for a parameter-free statement.

288290

291+* `manipulate_` is like `manipulate` for a returning-free statement.

292+

289293* `runQueryParams` is like `manipulateParams` for query statements.

290294

291295* `runQuery` is like `runQueryParams` for a parameter-free statement.

@@ -299,11 +303,11 @@ instance IndexedMonadTransPQ PQ where

299303* `forPrepared` is a flipped `traversePrepared`

300304

301305* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

302− containers and returns unit.

306+ containers for a returning-free statement.

303307

304308* `forPrepared_` is a flipped `traversePrepared_`.

305309

306−* `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

307311 into your monad.

308312

309313To define an instance, you can minimally define only `manipulateParams`,

@@ -311,235 +315,263 @@ To define an instance, you can minimally define only `manipulateParams`,

311315a default instance.

312316

313317-}

314−class Monad pq => MonadPQ schema pq | pq -> schema where

318+class Monad pq => MonadPQ schemas pq | pq -> schemas where

315319 manipulateParams

316− :: ToParams x params

317− => Manipulation schema params ys

318− -- ^ `insertRows`, `update` or `deleteFrom`

320+ :: (ToParams x params, All OidOfParam params)

321+ => Manipulation '[] schemas params ys

322+ -- ^ `insertInto`, `update` or `deleteFrom`

319323 -> x -> pq (K LibPQ.Result ys)

320324 default manipulateParams

321− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

322− => ToParams x params

323− => Manipulation schema params ys

324− -- ^ `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`

325329 -> x -> pq (K LibPQ.Result ys)

326330 manipulateParams manipulation params = lift $

327331 manipulateParams manipulation params

328332

329− 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)

330341 manipulate statement = manipulateParams statement ()

331342

343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()

344+ manipulate_ = void . manipulate

345+

332346 runQueryParams

333− :: ToParams x params

334− => Query schema params ys

347+ :: (ToParams x params, All OidOfParam params)

348+ => Query '[] '[] schemas params ys

335349 -- ^ `select` and friends

336350 -> x -> pq (K LibPQ.Result ys)

337351 runQueryParams = manipulateParams . queryStatement

338352

339353 runQuery

340− :: Query schema '[] ys

354+ :: Query '[] '[] schemas '[] ys

341355 -- ^ `select` and friends

342356 -> pq (K LibPQ.Result ys)

343357 runQuery q = runQueryParams q ()

344358

345359 traversePrepared

346− :: (ToParams x params, Traversable list)

347− => Manipulation schema params ys

348− -- ^ `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

349363 -> list x -> pq (list (K LibPQ.Result ys))

350364 default traversePrepared

351− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

352− => (ToParams x params, Traversable list)

353− => 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))

354368 traversePrepared manipulation params = lift $

355369 traversePrepared manipulation params

356370

357371 forPrepared

358− :: (ToParams x params, Traversable list)

372+ :: (ToParams x params, Traversable list, All OidOfParam params)

359373 => list x

360− -> Manipulation schema params ys

361− -- ^ `insertRows`, `update` or `deleteFrom`

374+ -> Manipulation '[] schemas params ys

375+ -- ^ `insertInto`, `update` or `deleteFrom`

362376 -> pq (list (K LibPQ.Result ys))

363377 forPrepared = flip traversePrepared

364378

365379 traversePrepared_

366− :: (ToParams x params, Foldable list)

367− => Manipulation schema params '[]

368− -- ^ `insertRows`, `update` or `deleteFrom`

380+ :: (ToParams x params, Foldable list, All OidOfParam params)

381+ => Manipulation '[] schemas params '[]

382+ -- ^ `insertInto`, `update` or `deleteFrom`

369383 -> list x -> pq ()

370384 default traversePrepared_

371− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

372− => (ToParams x params, Foldable list)

373− => Manipulation schema params '[]

374− -- ^ `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`

375389 -> list x -> pq ()

376390 traversePrepared_ manipulation params = lift $

377391 traversePrepared_ manipulation params

378392

379393 forPrepared_

380− :: (ToParams x params, Foldable list)

394+ :: (ToParams x params, Foldable list, All OidOfParam params)

381395 => list x

382− -> Manipulation schema params '[]

383− -- ^ `insertRows`, `update` or `deleteFrom`

396+ -> Manipulation '[] schemas params '[]

397+ -- ^ `insertInto`, `update` or `deleteFrom`

384398 -> pq ()

385399 forPrepared_ = flip traversePrepared_

386400

387401 liftPQ :: (LibPQ.Connection -> IO a) -> pq a

388402 default liftPQ

389− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

390404 => (LibPQ.Connection -> IO a) -> pq a

391405 liftPQ = lift . liftPQ

392406

393−instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)

394− => MonadPQ schema (PQ schema0 schema1 io) where

407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)

408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where

395409

396410 manipulateParams

397− (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =

411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =

398412 PQ $ \ (K conn) -> do

399413 let

400− toParam' encoding =

401− (LibPQ.invalidOid, encodingBytes encoding, LibPQ.Binary)

402− 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

403425 q' = q <> ";"

404− resultMaybe <- liftBase $ LibPQ.execParams conn q' params' LibPQ.Binary

426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary

405427 case resultMaybe of

406− Nothing -> error

428+ Nothing -> throw $ ResultException

407429 "manipulateParams: LibPQ.execParams returned no results"

408430 Just result -> do

409− tryResult result

431+ okResult_ result

410432 return $ K (K result)

411433

412434 traversePrepared

413− (UnsafeManipulation q :: Manipulation schema xs ys) (list :: list x) =

414− PQ $ \ (K conn) -> liftBase $ do

415− let temp = "temporary_statement"

416− 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')

417446 case prepResultMaybe of

418− Nothing -> error

447+ Nothing -> throw $ ResultException

419448 "traversePrepared: LibPQ.prepare returned no results"

420− Just prepResult -> tryResult prepResult

449+ Just prepResult -> okResult_ prepResult

421450 results <- for list $ \ params -> do

422451 let

423− toParam' encoding = (encodingBytes encoding,LibPQ.Binary)

452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

424453 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

425454 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

426455 case resultMaybe of

427− Nothing -> error

456+ Nothing -> throw $ ResultException

428457 "traversePrepared: LibPQ.execParams returned no results"

429458 Just result -> do

430− tryResult result

459+ okResult_ result

431460 return $ K result

432461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

433462 case deallocResultMaybe of

434− Nothing -> error

463+ Nothing -> throw $ ResultException

435464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

436− Just deallocResult -> tryResult deallocResult

465+ Just deallocResult -> okResult_ deallocResult

437466 return (K results)

438467

439468 traversePrepared_

440− (UnsafeManipulation q :: Manipulation schema xs '[]) (list :: list x) =

441− PQ $ \ (K conn) -> liftBase $ do

442− let temp = "temporary_statement"

443− 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')

444480 case prepResultMaybe of

445− Nothing -> error

481+ Nothing -> throw $ ResultException

446482 "traversePrepared_: LibPQ.prepare returned no results"

447− Just prepResult -> tryResult prepResult

483+ Just prepResult -> okResult_ prepResult

448484 for_ list $ \ params -> do

449485 let

450486 toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

451487 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

452488 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

453489 case resultMaybe of

454− Nothing -> error

490+ Nothing -> throw $ ResultException

455491 "traversePrepared_: LibPQ.execParams returned no results"

456− Just result -> tryResult result

492+ Just result -> okResult_ result

457493 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

458494 case deallocResultMaybe of

459− Nothing -> error

495+ Nothing -> throw $ ResultException

460496 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

461− Just deallocResult -> tryResult deallocResult

497+ Just deallocResult -> okResult_ deallocResult

462498 return (K ())

463499

464500 liftPQ pq = PQ $ \ (K conn) -> do

465− y <- liftBase $ pq conn

501+ y <- liftIO $ pq conn

466502 return (K y)

467503

468−instance MonadPQ schema m => MonadPQ schema (IdentityT m)

469−instance MonadPQ schema m => MonadPQ schema (ReaderT r m)

470−instance MonadPQ schema m => MonadPQ schema (Strict.StateT s m)

471−instance MonadPQ schema m => MonadPQ schema (Lazy.StateT s m)

472−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.WriterT w m)

473−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.WriterT w m)

474−instance MonadPQ schema m => MonadPQ schema (MaybeT m)

475−instance MonadPQ schema m => MonadPQ schema (ExceptT e m)

476−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.RWST r w s m)

477−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.RWST r w s m)

478−instance MonadPQ schema m => MonadPQ schema (ContT r m)

479−instance MonadPQ schema m => MonadPQ schema (ListT m)

480−

481−instance (Monad m, schema0 ~ schema1)

482− => 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

483518 pure x = PQ $ \ _conn -> pure (K x)

484519 (<*>) = pqAp

485520

486−instance (Monad m, schema0 ~ schema1)

487− => Monad (PQ schema0 schema1 m) where

521+instance (Monad m, schemas0 ~ schemas1)

522+ => Monad (PQ schemas0 schemas1 m) where

488523 return = pure

489524 (>>=) = flip pqBind

490525

491−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

492531 hoist f (PQ pq) = PQ (f . pq)

493532

494−instance schema0 ~ schema1 => MonadTrans (PQ schema0 schema1) where

533+instance schemas0 ~ schemas1 => MonadTrans (PQ schemas0 schemas1) where

495534 lift m = PQ $ \ _conn -> do

496535 x <- m

497536 return (K x)

498537

499−instance schema0 ~ schema1 => MMonad (PQ schema0 schema1) where

538+instance schemas0 ~ schemas1 => MMonad (PQ schemas0 schemas1) where

500539 embed f (PQ pq) = PQ $ \ conn -> do

501540 evalPQ (f (pq conn)) conn

502541

503−instance (MonadBase b m, schema0 ~ schema1)

504− => MonadBase b (PQ schema0 schema1 m) where

505− liftBase = lift . liftBase

506−

507−-- | A snapshot of the state of a `PQ` computation.

508−type PQRun schema =

509− forall m x. Monad m => PQ schema schema m x -> m (K x schema)

542+instance (MonadIO m, schema0 ~ schema1)

543+ => MonadIO (PQ schema0 schema1 m) where

544+ liftIO = lift . liftIO

510545

511−-- | Helper function in defining `MonadBaseControl` instance for `PQ`.

512−pqliftWith :: Functor m => (PQRun schema -> m a) -> PQ schema schema m a

513−pqliftWith f = PQ $ \ conn ->

514− fmap K (f $ \ pq -> unPQ pq conn)

515−

516−instance (MonadBaseControl b m, schema0 ~ schema1)

517− => MonadBaseControl b (PQ schema0 schema1 m) where

518− type StM (PQ schema0 schema1 m) x = StM m (K x schema0)

519− liftBaseWith f =

520− pqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

521− 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)

522554

523555-- | Get a row corresponding to a given row number from a `LibPQ.Result`,

524556-- throwing an exception if the row number is out of bounds.

525557getRow

526− :: (FromRow columns y, MonadBase IO io)

558+ :: (FromRow columns y, MonadIO io)

527559 => LibPQ.Row

528560 -- ^ row number

529561 -> K LibPQ.Result columns

530562 -- ^ result

531563 -> io y

532−getRow r (K result :: K LibPQ.Result columns) = liftBase $ do

564+getRow r (K result :: K LibPQ.Result columns) = liftIO $ do

533565 numRows <- LibPQ.ntuples result

534− when (numRows < r) $ error $

535− "getRow: expected at least " <> show r <> "rows but only saw "

536− <> show numRows

566+ when (numRows < r) $ throw $ ResultException $

567+ "getRow: expected at least " <> pack (show r) <> "rows but only saw "

568+ <> pack (show numRows)

537569 let len = fromIntegral (lengthSList (Proxy @columns))

538570 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

539571 case fromList row' of

540− Nothing -> error "getRow: found unexpected length"

572+ Nothing -> throw $ ResultException "getRow: found unexpected length"

541573 Just row -> case fromRow @columns row of

542− Left parseError -> error $ "fromRow: " <> unpack parseError

574+ Left parseError -> throw $ ParseException $ "getRow: " <> parseError

543575 Right y -> return y

544576

545577-- | Intended to be used for unfolding in streaming libraries, `nextRow`

@@ -547,72 +579,72 @@ getRow r (K result :: K LibPQ.Result columns) = liftBase $ do

547579-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,

548580-- otherwise returning the row along with the next row number.

549581nextRow

550− :: (FromRow columns y, MonadBase IO io)

582+ :: (FromRow columns y, MonadIO io)

551583 => LibPQ.Row -- ^ total number of rows

552584 -> K LibPQ.Result columns -- ^ result

553585 -> LibPQ.Row -- ^ row number

554586 -> io (Maybe (LibPQ.Row,y))

555587nextRow total (K result :: K LibPQ.Result columns) r

556− = liftBase $ if r >= total then return Nothing else do

588+ = liftIO $ if r >= total then return Nothing else do

557589 let len = fromIntegral (lengthSList (Proxy @columns))

558590 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

559591 case fromList row' of

560− Nothing -> error "nextRow: found unexpected length"

592+ Nothing -> throw $ ResultException "nextRow: found unexpected length"

561593 Just row -> case fromRow @columns row of

562− Left parseError -> error $ "nextRow: " <> unpack parseError

594+ Left parseError -> throw $ ParseException $ "nextRow: " <> parseError

563595 Right y -> return $ Just (r+1, y)

564596

565597-- | Get all rows from a `LibPQ.Result`.

566598getRows

567− :: (FromRow columns y, MonadBase IO io)

599+ :: (FromRow columns y, MonadIO io)

568600 => K LibPQ.Result columns -- ^ result

569601 -> io [y]

570−getRows (K result :: K LibPQ.Result columns) = liftBase $ do

602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do

571603 let len = fromIntegral (lengthSList (Proxy @columns))

572604 numRows <- LibPQ.ntuples result

573605 for [0 .. numRows - 1] $ \ r -> do

574606 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

575607 case fromList row' of

576− Nothing -> error "getRows: found unexpected length"

608+ Nothing -> throw $ ResultException "getRows: found unexpected length"

577609 Just row -> case fromRow @columns row of

578− Left parseError -> error $ "getRows: " <> unpack parseError

610+ Left parseError -> throw $ ParseException $ "getRows: " <> parseError

579611 Right y -> return y

580612

581613-- | Get the first row if possible from a `LibPQ.Result`.

582614firstRow

583− :: (FromRow columns y, MonadBase IO io)

615+ :: (FromRow columns y, MonadIO io)

584616 => K LibPQ.Result columns -- ^ result

585617 -> io (Maybe y)

586−firstRow (K result :: K LibPQ.Result columns) = liftBase $ do

618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do

587619 numRows <- LibPQ.ntuples result

588620 if numRows <= 0 then return Nothing else do

589621 let len = fromIntegral (lengthSList (Proxy @columns))

590622 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]

591623 case fromList row' of

592− Nothing -> error "firstRow: found unexpected length"

624+ Nothing -> throw $ ResultException "firstRow: found unexpected length"

593625 Just row -> case fromRow @columns row of

594− Left parseError -> error $ "firstRow: " <> unpack parseError

626+ Left parseError -> throw $ ParseException $ "firstRow: " <> parseError

595627 Right y -> return $ Just y

596628

597629-- | Lifts actions on results from @LibPQ@.

598630liftResult

599− :: MonadBase IO io

631+ :: MonadIO io

600632 => (LibPQ.Result -> IO x)

601633 -> K LibPQ.Result results -> io x

602−liftResult f (K result) = liftBase $ f result

634+liftResult f (K result) = liftIO $ f result

603635

604636-- | Returns the number of rows (tuples) in the query result.

605−ntuples :: MonadBase IO io => K LibPQ.Result columns -> io LibPQ.Row

637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row

606638ntuples = liftResult LibPQ.ntuples

607639

608640-- | Returns the result status of the command.

609−resultStatus :: MonadBase IO io => K LibPQ.Result results -> io LibPQ.ExecStatus

641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus

610642resultStatus = liftResult LibPQ.resultStatus

611643

612644-- | Returns the error message most recently generated by an operation

613645-- on the connection.

614646resultErrorMessage

615− :: MonadBase IO io => K LibPQ.Result results -> io (Maybe ByteString)

647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)

616648resultErrorMessage = liftResult LibPQ.resultErrorMessage

617649

618650-- | Returns the error code most recently generated by an operation

@@ -620,25 +652,29 @@ resultErrorMessage = liftResult LibPQ.resultErrorMessage

620652--

621653-- https://www.postgresql.org/docs/current/static/errcodes-appendix.html

622654resultErrorCode

623− :: MonadBase IO io

655+ :: MonadIO io

624656 => K LibPQ.Result results

625657 -> io (Maybe ByteString)

626658resultErrorCode = liftResult (flip LibPQ.resultErrorField LibPQ.DiagSqlstate)

627659

628−data SquealException

629− = SquealException

660+-- | the state of LibPQ

661+data PQState = PQState

630662 { sqlExecStatus :: LibPQ.ExecStatus

631663 , sqlStateCode :: Maybe ByteString

632664 -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html

633665 , sqlErrorMessage :: Maybe ByteString

634666 } deriving (Eq, Show)

667+

668+-- | `Exception`s that can be thrown by Squeal.

669+data SquealException

670+ = PQException PQState

671+ | ResultException Text

672+ | ParseException Text

673+ deriving (Eq, Show)

635674instance Exception SquealException

636675

637−tryResult

638− :: MonadBase IO io

639− => LibPQ.Result

640− -> io ()

641−tryResult result = liftBase $ do

676+okResult_ :: MonadIO io => LibPQ.Result -> io ()

677+okResult_ result = liftIO $ do

642678 status <- LibPQ.resultStatus result

643679 case status of

644680 LibPQ.CommandOk -> return ()

@@ -646,4 +682,31 @@ tryResult result = liftBase $ do

646682 _ -> do

647683 stateCode <- LibPQ.resultErrorField result LibPQ.DiagSqlstate

648684 msg <- LibPQ.resultErrorMessage result

649− throw $ SquealException 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

691+

692+-- | Catch `SquealException`s.

693+catchSqueal

694+ :: MonadUnliftIO io

695+ => io a

696+ -> (SquealException -> io a) -- ^ handler

697+ -> io a

698+catchSqueal = catch

699+

700+-- | Handle `SquealException`s.

701+handleSqueal

702+ :: MonadUnliftIO io

703+ => (SquealException -> io a) -- ^ handler

704+ -> io a -> io a

705+handleSqueal = handle

706+

707+-- | `Either` return a `SquealException` or a result.

708+trySqueal

709+ :: MonadUnliftIO io

710+ => io a

711+ -> io (Either SquealException a)

712+trySqueal = try

squeal-postgresql/src/Squeal/PostgreSQL/Pool.hs+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+648−624

@@ -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

@@ -28,72 +32,58 @@ Squeal queries.

2832

2933module Squeal.PostgreSQL.Query

3034 ( -- * Queries

31− Query (UnsafeQuery, renderQuery)

35+ Query_

36+ , Query (..)

37+ -- ** Select

38+ , select

39+ , select_

40+ , selectDistinct

41+ , selectDistinct_

42+ , selectDistinctOn

43+ , selectDistinctOn_

44+ , Selection (..)

45+ -- ** Values

46+ , values

47+ , values_

48+ -- ** Set Operations

3249 , union

3350 , unionAll

3451 , intersect

3552 , intersectAll

3653 , except

3754 , exceptAll

38− -- * Select

39− , select

40− , selectDistinct

41− , selectStar

42− , selectDistinctStar

43− , selectDotStar

44− , selectDistinctDotStar

45− , values

46− , values_

55+ -- ** With

56+ , With (..)

57+ , CommonTableExpression (..)

58+ , withRecursive

4759 -- * Table Expressions

4860 , TableExpression (..)

49− , renderTableExpression

5061 , from

5162 , where_

5263 , groupBy

5364 , having

54− , orderBy

5565 , limit

5666 , offset

57− -- ** JSON table expressions

58− , PGjson_each

59− , PGjsonb_each

60− , jsonEach

61− , jsonbEach

62− , jsonEachAsText

63− , jsonbEachAsText

64− , jsonPopulateRecordAs

65− , jsonbPopulateRecordAs

66− , jsonPopulateRecordSetAs

67− , jsonbPopulateRecordSetAs

68− , jsonToRecordAs

69− , jsonbToRecordAs

70− , jsonToRecordSetAs

71− , jsonbToRecordSetAs

72− -- * From

67+ -- * From Clauses

7368 , FromClause (..)

7469 , table

7570 , subquery

7671 , view

72+ , common

7773 , crossJoin

7874 , innerJoin

7975 , leftOuterJoin

8076 , rightOuterJoin

8177 , fullOuterJoin

8278 -- * Grouping

83− , By (By1, By2)

84− , renderBy

85− , GroupByClause (NoGroups, Group)

86− , renderGroupByClause

87− , HavingClause (NoHaving, Having)

88− , renderHavingClause

89− -- * Sorting

90− , SortExpression (..)

91− , renderSortExpression

79+ , By (..)

80+ , GroupByClause (..)

81+ , HavingClause (..)

9282 ) where

9383

9484import Control.DeepSeq

9585import Data.ByteString (ByteString)

96−import Data.Monoid hiding (All)

86+import Data.Kind (Type)

9787import Data.String

9888import Data.Word

9989import Generics.SOP hiding (from)

@@ -101,25 +91,76 @@ import GHC.TypeLits

10191

10292import qualified GHC.Generics as GHC

10393

94+import Squeal.PostgreSQL.Alias

10495import 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

105101import Squeal.PostgreSQL.Render

106102import Squeal.PostgreSQL.Schema

107103

104+-- $setup

105+-- >>> import Squeal.PostgreSQL

106+-- >>> import Data.Int (Int32, Int64)

107+-- >>> import Data.Monoid (Sum (..))

108+-- >>> import Data.Text (Text)

109+-- >>> import qualified Generics.SOP as SOP

110+

111+{- |

112+The process of retrieving or the command to retrieve data from

113+a database is called a `Query`.

114+

115+The general `Query` type is parameterized by

116+

117+* @outer :: FromType@ - outer scope for a correlated subquery,

118+* @commons :: FromType@ - scope for all `common` table expressions,

119+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

120+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

121+* @row :: RowType@ - return type of the `Query`.

122+-}

123+newtype Query

124+ (outer :: FromType)

125+ (commons :: FromType)

126+ (schemas :: SchemasType)

127+ (params :: [NullityType])

128+ (row :: RowType)

129+ = UnsafeQuery { renderQuery :: ByteString }

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

131+instance RenderSQL (Query outer commons schemas params row) where renderSQL = renderQuery

132+

108133{- |

109−The process of retrieving or the command to retrieve data from a database

110−is called a `Query`. The `select`, `selectStar`, `selectDotStar`,

111−`selectDistinct`, `selectDistinctStar` and `selectDistinctDotStar` commands

112−are used to specify queries.

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+:}

113155

114156simple query:

115157

158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

116160>>> :{

117161let

118− query :: Query

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

120− '[]

121− '["col" ::: 'Null 'PGint4]

122− query = selectStar (from (table #tab))

162+ query :: Query_ (Public Schema) () (Row Int32 Int32)

163+ query = select Star (from (table #tab))

123164in printSQL query

124165:}

125166SELECT * FROM "tab" AS "tab"

@@ -128,34 +169,22 @@ restricted query:

128169

129170>>> :{

130171let

131− query :: Query

132− '[ "tab" ::: 'Table ('[] :=>

133− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

134− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

135− '[]

136− '[ "sum" ::: 'NotNull 'PGint4

137− , "col1" ::: 'NotNull 'PGint4 ]

172+ query :: Query_ (Public Schema) () (Row Int32 Int32)

138173 query =

139− select

140− ((#col1 + #col2) `as` #sum :* #col1)

174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)

141175 ( from (table #tab)

142176 & where_ (#col1 .> #col2)

143177 & where_ (#col2 .> 0) )

144178in printSQL query

145179:}

146−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))

147181

148182subquery:

149183

150184>>> :{

151185let

152− query :: Query

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

154− '[]

155− '["col" ::: 'Null 'PGint4]

156− query =

157− selectStar

158− (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)))

159188in printSQL query

160189:}

161190SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"

@@ -164,12 +193,8 @@ limits and offsets:

164193

165194>>> :{

166195let

167− query :: Query

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

169− '[]

170− '["col" ::: 'Null 'PGint4]

171− query = selectStar

172− (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)

173198in printSQL query

174199:}

175200SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4

@@ -178,85 +203,80 @@ parameterized query:

178203

179204>>> :{

180205let

181− query :: Query

182− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8])]

183− '[ 'NotNull 'PGfloat8]

184− '["col" ::: 'NotNull 'PGfloat8]

185− query = selectStar

186− (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))

187208in printSQL query

188209:}

189−SELECT * FROM "tab" AS "tab" WHERE ("col" > ($1 :: float8))

210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))

190211

191212aggregation query:

192213

193214>>> :{

194215let

195− query :: Query

196− '[ "tab" ::: 'Table ('[] :=>

197− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

198− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

199− '[]

200− '[ "sum" ::: 'NotNull 'PGint4

201− , "col1" ::: 'NotNull 'PGint4 ]

216+ query :: Query_ (Public Schema) () (Row Int64 Int32)

202217 query =

203− select (sum_ #col2 `as` #sum :* #col1)

218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)

204219 ( from (table (#tab `as` #table1))

205220 & groupBy #col1

206− & having (#col1 + sum_ #col2 .> 1) )

221+ & having (sum_ (Distinct #col2) .> 1) )

207222in printSQL query

208223:}

209−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)

210225

211226sorted query:

212227

213228>>> :{

214229let

215− query :: Query

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

217− '[]

218− '["col" ::: 'Null 'PGint4]

219− query = selectStar

220− (from (table #tab) & orderBy [#col & AscNullsFirst])

230+ query :: Query_ (Public Schema) () (Row Int32 Int32)

231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])

221232in printSQL query

222233:}

223−SELECT * FROM "tab" AS "tab" ORDER BY "col" ASC NULLS FIRST

234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC

224235

225236joins:

226237

227−>>> :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+

228273>>> :{

229274let

230− query :: Query

231− '[ "orders" ::: 'Table (

232− '["pk_orders" ::: PrimaryKey '["id"]

233− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]

234− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>

235− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

236− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4

237− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4

238− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4

239− ])

240− , "customers" ::: 'Table (

241− '["pk_customers" ::: PrimaryKey '["id"]] :=>

242− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

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

244− ])

245− , "shippers" ::: 'Table (

246− '["pk_shippers" ::: PrimaryKey '["id"]] :=>

247− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

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

249− ])

250− ]

251− '[]

252− '[ "order_price" ::: 'NotNull 'PGfloat4

253− , "customer_name" ::: 'NotNull 'PGtext

254− , "shipper_name" ::: 'NotNull 'PGtext

255− ]

256− query = select

257− ( #o ! #price `as` #order_price :*

258− #c ! #name `as` #customer_name :*

259− #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 )

260280 ( from (table (#orders `as` #o)

261281 & innerJoin (table (#customers `as` #c))

262282 (#o ! #customer_id .== #c ! #id)

@@ -264,190 +284,345 @@ let

264284 (#o ! #shipper_id .== #s ! #id)) )

265285in printSQL query

266286:}

267−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")

268288

269289self-join:

270290

271291>>> :{

272292let

273− query :: Query

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

275− '[]

276− '["col" ::: 'Null 'PGint4]

277− query = selectDotStar #t1

293+ query :: Query_ (Public Schema) () (Row Int32 Int32)

294+ query = select

295+ (#t1 & DotStar)

278296 (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))

279297in printSQL query

280298:}

281299SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"

282300

301+value queries:

302+

303+>>> :{

304+let

305+ query :: Query_ schemas () (Row String Bool)

306+ query = values

307+ ("true" `as` #col1 :* true `as` #col2)

308+ ["false" `as` #col1 :* false `as` #col2]

309+in printSQL query

310+:}

311+SELECT * FROM (VALUES (E'true', TRUE), (E'false', FALSE)) AS t ("col1", "col2")

312+

283313set operations:

284314

285315>>> :{

286316let

287− query :: Query

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

289− '[]

290− '["col" ::: 'Null 'PGint4]

291− query =

292− selectStar (from (table #tab))

293− `unionAll`

294− 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))

295319in printSQL query

296320:}

297321(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")

322+

323+with queries:

324+

325+>>> :{

326+let

327+ query :: Query_ (Public Schema) () (Row Int32 Int32)

328+ query = with (

329+ select Star (from (table #tab)) `as` #cte1 :>>

330+ select Star (from (common #cte1)) `as` #cte2

331+ ) (select Star (from (common #cte2)))

332+in printSQL query

333+:}

334+WITH "cte1" AS (SELECT * FROM "tab" AS "tab"), "cte2" AS (SELECT * FROM "cte1" AS "cte1") SELECT * FROM "cte2" AS "cte2"

335+

336+window function queries

337+

338+>>> :{

339+let

340+ query :: Query_ (Public Schema) () (Row Int32 Int64)

341+ query = select

342+ (#col1 & Also (rank `as` #col2 `Over` (partitionBy #col1 & orderBy [#col2 & Asc])))

343+ (from (table #tab))

344+in printSQL query

345+:}

346+SELECT "col1" AS "col1", rank() OVER (PARTITION BY "col1" ORDER BY "col2" ASC) AS "col2" FROM "tab" AS "tab"

347+

348+correlated subqueries

349+

350+>>> :{

351+let

352+ query :: Query_ (Public Schema) () (Only Int32)

353+ query =

354+ select (#col1 `as` #fromOnly) (from (table (#tab `as` #t1))

355+ & where_ (exists (

356+ select Star (from (table (#tab `as` #t2))

357+ & where_ (#t2 ! #col2 .== #t1 ! #col1)))))

358+in printSQL query

359+:}

360+SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))

361+

298362-}

299−newtype Query

300− (schema :: SchemaType)

301− (params :: [NullityType])

302− (columns :: RelationType)

303− = UnsafeQuery { renderQuery :: ByteString }

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

305−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)

306369

307370-- | The results of two queries can be combined using the set operation

308371-- `union`. Duplicate rows are eliminated.

309372union

310− :: Query schema params columns

311− -> Query schema params columns

312− -> 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

313376q1 `union` q2 = UnsafeQuery $

314− parenthesized (renderQuery q1)

377+ parenthesized (renderSQL q1)

315378 <+> "UNION"

316− <+> parenthesized (renderQuery q2)

379+ <+> parenthesized (renderSQL q2)

317380

318381-- | The results of two queries can be combined using the set operation

319382-- `unionAll`, the disjoint union. Duplicate rows are retained.

320383unionAll

321− :: Query schema params columns

322− -> Query schema params columns

323− -> 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

324387q1 `unionAll` q2 = UnsafeQuery $

325− parenthesized (renderQuery q1)

388+ parenthesized (renderSQL q1)

326389 <+> "UNION" <+> "ALL"

327− <+> parenthesized (renderQuery q2)

390+ <+> parenthesized (renderSQL q2)

328391

329392-- | The results of two queries can be combined using the set operation

330393-- `intersect`, the intersection. Duplicate rows are eliminated.

331394intersect

332− :: Query schema params columns

333− -> Query schema params columns

334− -> 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

335398q1 `intersect` q2 = UnsafeQuery $

336− parenthesized (renderQuery q1)

399+ parenthesized (renderSQL q1)

337400 <+> "INTERSECT"

338− <+> parenthesized (renderQuery q2)

401+ <+> parenthesized (renderSQL q2)

339402

340403-- | The results of two queries can be combined using the set operation

341404-- `intersectAll`, the intersection. Duplicate rows are retained.

342405intersectAll

343− :: Query schema params columns

344− -> Query schema params columns

345− -> 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

346409q1 `intersectAll` q2 = UnsafeQuery $

347− parenthesized (renderQuery q1)

410+ parenthesized (renderSQL q1)

348411 <+> "INTERSECT" <+> "ALL"

349− <+> parenthesized (renderQuery q2)

412+ <+> parenthesized (renderSQL q2)

350413

351414-- | The results of two queries can be combined using the set operation

352415-- `except`, the set difference. Duplicate rows are eliminated.

353416except

354− :: Query schema params columns

355− -> Query schema params columns

356− -> 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

357420q1 `except` q2 = UnsafeQuery $

358− parenthesized (renderQuery q1)

421+ parenthesized (renderSQL q1)

359422 <+> "EXCEPT"

360− <+> parenthesized (renderQuery q2)

423+ <+> parenthesized (renderSQL q2)

361424

362425-- | The results of two queries can be combined using the set operation

363426-- `exceptAll`, the set difference. Duplicate rows are retained.

364427exceptAll

365− :: Query schema params columns

366− -> Query schema params columns

367− -> 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

368431q1 `exceptAll` q2 = UnsafeQuery $

369− parenthesized (renderQuery q1)

432+ parenthesized (renderSQL q1)

370433 <+> "EXCEPT" <+> "ALL"

371− <+> parenthesized (renderQuery q2)

434+ <+> parenthesized (renderSQL q2)

372435

373436{-----------------------------------------

374437SELECT queries

375438-----------------------------------------}

376439

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+

377525-- | the `TableExpression` in the `select` command constructs an intermediate

378526-- virtual table by possibly combining tables, views, eliminating rows,

379527-- grouping, etc. This table is finally passed on to processing by

380−-- the select list. The select list determines which columns of

528+-- the select list. The `Selection` determines which columns of

381529-- the intermediate table are actually output.

382530select

383− :: SListI columns

384− => NP (Aliased (Expression schema relations grouping params)) (column ': columns)

385− -- ^ select list

386− -> TableExpression schema params relations grouping

531+ :: (SListI row, row ~ (x ': xs))

532+ => Selection outer commons grp schemas params from row

533+ -- ^ selection

534+ -> TableExpression outer commons grp schemas params from

387535 -- ^ intermediate virtual table

388− -> Query schema params (column ': columns)

389−select list rels = UnsafeQuery $

536+ -> Query outer commons schemas params row

537+select selection tabexpr = UnsafeQuery $

390538 "SELECT"

391− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

392− <+> 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

393552

394553-- | After the select list has been processed, the result table can

395554-- be subject to the elimination of duplicate rows using `selectDistinct`.

396555selectDistinct

397− :: SListI columns

398− => NP (Aliased (Expression schema relations 'Ungrouped params)) (column ': columns)

399− -- ^ select list

400− -> TableExpression schema params relations 'Ungrouped

556+ :: (SListI columns, columns ~ (col ': cols))

557+ => Selection outer commons grp schemas params from columns

558+ -- ^ selection

559+ -> TableExpression outer commons grp schemas params from

401560 -- ^ intermediate virtual table

402− -> Query schema params (column ': columns)

403−selectDistinct list rels = UnsafeQuery $

561+ -> Query outer commons schemas params columns

562+selectDistinct selection tabexpr = UnsafeQuery $

404563 "SELECT DISTINCT"

405− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

406− <+> renderTableExpression rels

407−

408−-- | The simplest kind of query is `selectStar` which emits all columns

409−-- that the table expression produces.

410−selectStar

411− :: HasUnique relation relations columns

412− => TableExpression schema params relations 'Ungrouped

413− -- ^ intermediate virtual table

414− -> Query schema params columns

415−selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels

416−

417−-- | A `selectDistinctStar` emits all columns that the table expression

418−-- produces and eliminates duplicate rows.

419−selectDistinctStar

420− :: HasUnique relation relations columns

421− => TableExpression schema params relations 'Ungrouped

564+ <+> renderSQL selection

565+ <+> renderSQL tabexpr

566+

567+-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead

568+-- of a general `Selection`.

569+selectDistinct_

570+ :: (SListI columns, columns ~ (col ': cols))

571+ => NP (Aliased (Expression outer commons grp schemas params from)) columns

572+ -- ^ select list

573+ -> TableExpression outer commons grp schemas params from

422574 -- ^ intermediate virtual table

423− -> Query schema params columns

424−selectDistinctStar rels = UnsafeQuery $

425− "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels

426−

427−-- | When working with multiple tables, it can also be useful to ask

428−-- for all the columns of a particular table, using `selectDotStar`.

429−selectDotStar

430− :: Has relation relations columns

431− => Alias relation

432− -- ^ particular virtual subtable

433− -> TableExpression schema params relations 'Ungrouped

575+ -> Query outer commons schemas params columns

576+selectDistinct_ = selectDistinct . List

577+

578+{-|

579+`selectDistinctOn` keeps only the first row of each set of rows where

580+the given expressions evaluate to equal. The DISTINCT ON expressions are

581+interpreted using the same rules as for ORDER BY. ORDER BY is used to

582+ensure that the desired row appears first.

583+

584+The DISTINCT ON expression(s) must match the leftmost ORDER BY expression(s).

585+The ORDER BY clause will normally contain additional expression(s) that

586+determine the desired precedence of rows within each DISTINCT ON group.

587+

588+In order to guarantee they match and reduce redundancy, this function

589+will prepend the The DISTINCT ON expressions to the ORDER BY clause.

590+-}

591+selectDistinctOn

592+ :: (SListI columns, columns ~ (col ': cols))

593+ => [SortExpression outer commons grp schemas params from]

594+ -- ^ DISTINCT ON expression(s) and prepended to ORDER BY clause

595+ -> Selection outer commons grp schemas params from columns

596+ -- ^ selection

597+ -> TableExpression outer commons grp schemas params from

434598 -- ^ intermediate virtual table

435− -> Query schema params columns

436−selectDotStar rel relations = UnsafeQuery $

437− "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression relations

438−

439−-- | A `selectDistinctDotStar` asks for all the columns of a particular table,

440−-- and eliminates duplicate rows.

441−selectDistinctDotStar

442− :: Has relation relations columns

443− => Alias relation

444− -- ^ particular virtual table

445− -> TableExpression schema params relations 'Ungrouped

599+ -> Query outer commons schemas params columns

600+selectDistinctOn distincts selection tab = UnsafeQuery $

601+ "SELECT DISTINCT ON"

602+ <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))

603+ <+> renderSQL selection

604+ <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})

605+ where

606+ renderDistinctOn = \case

607+ Asc expression -> renderSQL expression

608+ Desc expression -> renderSQL expression

609+ AscNullsFirst expression -> renderSQL expression

610+ DescNullsFirst expression -> renderSQL expression

611+ AscNullsLast expression -> renderSQL expression

612+ DescNullsLast expression -> renderSQL expression

613+

614+-- | Like `selectDistinctOn` but takes an `NP` list of `Expression`s instead

615+-- of a general `Selection`.

616+selectDistinctOn_

617+ :: (SListI columns, columns ~ (col ': cols))

618+ => [SortExpression outer commons grp schemas params from]

619+ -- ^ distinct on and return the first row in ordering

620+ -> NP (Aliased (Expression outer commons grp schemas params from)) columns

621+ -- ^ selection

622+ -> TableExpression outer commons grp schemas params from

446623 -- ^ intermediate virtual table

447− -> Query schema params columns

448−selectDistinctDotStar rel relations = UnsafeQuery $

449− "SELECT DISTINCT" <+> renderAlias rel <> ".*"

450− <+> renderTableExpression relations

624+ -> Query outer commons schemas params columns

625+selectDistinctOn_ distincts = selectDistinctOn distincts . List

451626

452627-- | `values` computes a row value or set of row values

453628-- specified by value expressions. It is most commonly used

@@ -455,16 +630,16 @@ selectDistinctDotStar rel relations = UnsafeQuery $

455630-- but it can be used on its own.

456631--

457632-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]

458−-- >>> 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

459634-- >>> printSQL query

460635-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")

461636values

462637 :: SListI cols

463− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

464− -> [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]

465640 -- ^ When more than one row is specified, all the rows must

466641 -- must have the same number of elements

467− -> Query schema params cols

642+ -> Query outer commons schemas params cols

468643values rw rws = UnsafeQuery $ "SELECT * FROM"

469644 <+> parenthesized (

470645 "VALUES"

@@ -475,17 +650,17 @@ values rw rws = UnsafeQuery $ "SELECT * FROM"

475650 <+> parenthesized (renderCommaSeparated renderAliasPart rw)

476651 where

477652 renderAliasPart, renderValuePart

478− :: Aliased (Expression schema '[] 'Ungrouped params) ty -> ByteString

479− renderAliasPart (_ `As` name) = renderAlias name

480− 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

481656

482657-- | `values_` computes a row value or set of row values

483658-- specified by value expressions.

484659values_

485660 :: SListI cols

486− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

661+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

487662 -- ^ one row of values

488− -> Query schema params cols

663+ -> Query outer commons schemas params cols

489664values_ rw = values rw []

490665

491666{-----------------------------------------

@@ -499,15 +674,17 @@ Table Expressions

499674-- to a table on disk, a so-called base table, but more complex expressions

500675-- can be used to modify or combine base tables in various ways.

501676data TableExpression

502− (schema :: SchemaType)

677+ (outer :: FromType)

678+ (commons :: FromType)

679+ (grp :: Grouping)

680+ (schemas :: SchemasType)

503681 (params :: [NullityType])

504− (relations :: RelationsType)

505− (grouping :: Grouping)

682+ (from :: FromType)

506683 = TableExpression

507− { fromClause :: FromClause schema params relations

684+ { fromClause :: FromClause outer commons schemas params from

508685 -- ^ A table reference that can be a table name, or a derived table such

509686 -- as a subquery, a @JOIN@ construct, or complex combinations of these.

510− , whereClause :: [Condition schema relations 'Ungrouped params]

687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]

511688 -- ^ optional search coditions, combined with `.&&`. After the processing

512689 -- of the `fromClause` is done, each row of the derived virtual table

513690 -- is checked against the search condition. If the result of the

@@ -516,20 +693,20 @@ data TableExpression

516693 -- at least one column of the table generated in the `fromClause`;

517694 -- this is not required, but otherwise the WHERE clause will

518695 -- be fairly useless.

519− , groupByClause :: GroupByClause relations grouping

696+ , groupByClause :: GroupByClause grp from

520697 -- ^ The `groupByClause` is used to group together those rows in a table

521698 -- that have the same values in all the columns listed. The order in which

522699 -- the columns are listed does not matter. The effect is to combine each

523700 -- set of rows having common values into one group row that represents all

524701 -- rows in the group. This is done to eliminate redundancy in the output

525702 -- and/or compute aggregates that apply to these groups.

526− , havingClause :: HavingClause schema relations grouping params

703+ , havingClause :: HavingClause outer commons grp schemas params from

527704 -- ^ If a table has been grouped using `groupBy`, but only certain groups

528705 -- are of interest, the `havingClause` can be used, much like a

529706 -- `whereClause`, to eliminate groups from the result. Expressions in the

530707 -- `havingClause` can refer both to grouped expressions and to ungrouped

531708 -- expressions (which necessarily involve an aggregate function).

532− , orderByClause :: [SortExpression schema relations grouping params]

709+ , orderByClause :: [SortExpression outer commons grp schemas params from]

533710 -- ^ The `orderByClause` is for optional sorting. When more than one

534711 -- `SortExpression` is specified, the later (right) values are used to sort

535712 -- rows that are equal according to the earlier (left) values.

@@ -539,72 +716,69 @@ data TableExpression

539716 -- will be returned (but possibly fewer, if the query itself yields

540717 -- fewer rows).

541718 , offsetClause :: [Word64]

542− -- ^ The `offsetClause` is combined with `+` to give an offset count

719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count

543720 -- if nonempty. The offset count says to skip that many rows before

544721 -- beginning to return rows. The rows are skipped before the limit count

545722 -- is applied.

546− }

723+ } deriving (GHC.Generic)

547724

548725-- | Render a `TableExpression`

549−renderTableExpression

550− :: TableExpression schema params relations grouping

551− -> ByteString

552−renderTableExpression

553− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

554− [ "FROM ", renderFromClause frm'

555− , renderWheres whs'

556− , renderGroupByClause grps'

557− , renderHavingClause hvs'

558− , renderOrderByClause srts'

559− , renderLimits lims'

560− , renderOffsets offs'

561− ]

562− where

563− renderWheres = \case

564− [] -> ""

565− wh:[] -> " WHERE" <+> renderExpression wh

566− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

567− renderOrderByClause = \case

568− [] -> ""

569− srts -> " ORDER BY"

570− <+> commaSeparated (renderSortExpression <$> srts)

571− renderLimits = \case

572− [] -> ""

573− lims -> " LIMIT" <+> fromString (show (minimum lims))

574− renderOffsets = \case

575− [] -> ""

576− 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))

577751

578752-- | A `from` generates a `TableExpression` from a table reference that can be

579753-- a table name, or a derived table such as a subquery, a JOIN construct,

580754-- or complex combinations of these. A `from` may be transformed by `where_`,

581−-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

582756-- to match the left-to-right sequencing of their placement in SQL.

583757from

584− :: FromClause schema params relations -- ^ table reference

585− -> TableExpression schema params relations 'Ungrouped

586−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 [] [] []

587761

588762-- | A `where_` is an endomorphism of `TableExpression`s which adds a

589763-- search condition to the `whereClause`.

590764where_

591− :: Condition schema relations 'Ungrouped params -- ^ filtering condition

592− -> TableExpression schema params relations grouping

593− -> TableExpression schema params relations grouping

765+ :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition

766+ -> TableExpression outer commons grp schemas params from

767+ -> TableExpression outer commons grp schemas params from

594768where_ wh rels = rels {whereClause = wh : whereClause rels}

595769

596770-- | A `groupBy` is a transformation of `TableExpression`s which switches

597−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform

771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform

598772-- a "grand total" aggregation query.

599773groupBy

600774 :: SListI bys

601− => NP (By relations) bys -- ^ grouped columns

602− -> TableExpression schema params relations 'Ungrouped

603− -> TableExpression schema params relations ('Grouped bys)

775+ => NP (By from) bys -- ^ grouped columns

776+ -> TableExpression outer commons 'Ungrouped schemas params from

777+ -> TableExpression outer commons ('Grouped bys) schemas params from

604778groupBy bys rels = TableExpression

605779 { fromClause = fromClause rels

606780 , whereClause = whereClause rels

607− , groupByClause = Group bys

781+ , groupByClause = group bys

608782 , havingClause = Having []

609783 , orderByClause = []

610784 , limitClause = limitClause rels

@@ -614,219 +788,31 @@ groupBy bys rels = TableExpression

614788-- | A `having` is an endomorphism of `TableExpression`s which adds a

615789-- search condition to the `havingClause`.

616790having

617− :: Condition schema relations ('Grouped bys) params -- ^ having condition

618− -> TableExpression schema params relations ('Grouped bys)

619− -> TableExpression schema params relations ('Grouped bys)

791+ :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition

792+ -> TableExpression outer commons ('Grouped bys) schemas params from

793+ -> TableExpression outer commons ('Grouped bys) schemas params from

620794having hv rels = rels

621795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

622796

623−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an

624−-- ordering to the right of the `orderByClause`.

625−orderBy

626− :: [SortExpression schema relations grouping params] -- ^ sort expressions

627− -> TableExpression schema params relations grouping

628− -> TableExpression schema params relations grouping

629−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

797+instance OrderBy TableExpression where

798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

630799

631800-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

632801-- `limitClause`.

633802limit

634803 :: Word64 -- ^ limit parameter

635− -> TableExpression schema params relations grouping

636− -> TableExpression schema params relations grouping

804+ -> TableExpression outer commons grp schemas params from

805+ -> TableExpression outer commons grp schemas params from

637806limit lim rels = rels {limitClause = lim : limitClause rels}

638807

639808-- | An `offset` is an endomorphism of `TableExpression`s which adds to the

640809-- `offsetClause`.

641810offset

642811 :: Word64 -- ^ offset parameter

643− -> TableExpression schema params relations grouping

644− -> TableExpression schema params relations grouping

812+ -> TableExpression outer commons grp schemas params from

813+ -> TableExpression outer commons grp schemas params from

645814offset off rels = rels {offsetClause = off : offsetClause rels}

646815

647−{-----------------------------------------

648−JSON stuff

649−-----------------------------------------}

650−

651−type PGjson_each_variant val tab =

652− '[ tab ::: '[ "key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull val ] ]

653−

654−-- | The type of a `json_each` `FromClause`.

655−type PGjson_each tab = PGjson_each_variant 'PGjson tab

656−-- | The type of a `jsonb_each` `FromClause`.

657−type PGjsonb_each tab = PGjson_each_variant 'PGjsonb tab

658−-- | The type of a `json_each_text` `FromClause`.

659−type PGjson_each_text tab = PGjson_each_variant 'PGtext tab

660−-- | The type of a `jsonb_each_text` `FromClause`.

661−type PGjsonb_each_text tab = PGjson_each_variant 'PGtext tab

662−

663−unsafeAliasedFromClauseExpression

664− :: Aliased (Expression schema' relations' grouping' params') ty'

665− -> FromClause schema params relations

666−unsafeAliasedFromClauseExpression aliasedExpr = UnsafeFromClause

667− (renderAliasedAs renderExpression aliasedExpr)

668−

669−-- | Expands the outermost JSON object into a set of key/value pairs.

670−jsonEach

671− :: Aliased (Expression schema '[] 'Ungrouped params) '(tab, nullity 'PGjson)

672− -> FromClause schema params (PGjson_each tab)

673−jsonEach (As jexpr jname) = unsafeAliasedFromClauseExpression

674− (As (unsafeFunction "json_each" jexpr) jname)

675−

676−-- | Expands the outermost binary JSON object into a set of key/value pairs.

677−jsonbEach

678− :: Aliased (Expression schema '[] 'Ungrouped params) '(tab, nullity 'PGjsonb)

679− -> FromClause schema params (PGjsonb_each tab)

680−jsonbEach (As jexpr jname) = unsafeAliasedFromClauseExpression

681− (As (unsafeFunction "jsonb_each" jexpr) jname)

682−

683−-- | Expands the outermost JSON object into a set of key/value pairs.

684−jsonEachAsText

685− :: Aliased (Expression schema '[] 'Ungrouped params) '(tab, nullity 'PGjson)

686− -> FromClause schema params (PGjson_each_text tab)

687−jsonEachAsText (As jexpr jname) = unsafeAliasedFromClauseExpression

688− (As (unsafeFunction "json_each" jexpr) jname)

689−

690−-- | Expands the outermost binary JSON object into a set of key/value pairs.

691−jsonbEachAsText

692− :: Aliased (Expression schema '[] 'Ungrouped params) '(tab, nullity 'PGjsonb)

693− -> FromClause schema params (PGjsonb_each_text tab)

694−jsonbEachAsText (As jexpr jname) = unsafeAliasedFromClauseExpression

695− (As (unsafeFunction "jsonb_each" jexpr) jname)

696−

697−nullRow

698− :: Has tab schema ('Table table)

699− => Alias tab

700− -> Expression schema relations grouping params

701− (nullity ('PGcomposite (TableToRelation table)))

702−nullRow tab = UnsafeExpression ("null::"<+>renderAlias tab)

703−

704−-- | Expands the JSON expression to a row whose columns match the record

705−-- type defined by the given table.

706−jsonPopulateRecordAs

707− :: (KnownSymbol alias, Has tab schema ('Table table))

708− => Alias tab

709− -> Expression schema '[] 'Ungrouped params (nullity 'PGjson)

710− -> Alias alias

711− -> FromClause schema params '[alias ::: TableToRelation table]

712−jsonPopulateRecordAs tableName expr alias = unsafeAliasedFromClauseExpression

713− (unsafeVariadicFunction "json_populate_record"

714− (nullRow tableName :* expr :* Nil) `As` alias)

715−

716−-- | Expands the binary JSON expression to a row whose columns match the record

717−-- type defined by the given table.

718−jsonbPopulateRecordAs

719− :: (KnownSymbol alias, Has tab schema ('Table table))

720− => Alias tab

721− -> Expression schema '[] 'Ungrouped params (nullity 'PGjsonb)

722− -> Alias alias

723− -> FromClause schema params '[alias ::: TableToRelation table]

724−jsonbPopulateRecordAs tableName expr alias = unsafeAliasedFromClauseExpression

725− (unsafeVariadicFunction "jsonb_populate_record"

726− (nullRow tableName :* expr :* Nil) `As` alias)

727−

728−-- | Expands the outermost array of objects in the given JSON expression to a

729−-- set of rows whose columns match the record type defined by the given table.

730−jsonPopulateRecordSetAs

731− :: (KnownSymbol alias, Has tab schema ('Table table))

732− => Alias tab

733− -> Expression schema '[] 'Ungrouped params (nullity 'PGjson)

734− -> Alias alias

735− -> FromClause schema params '[alias ::: TableToRelation table]

736−jsonPopulateRecordSetAs tableName expr alias = unsafeAliasedFromClauseExpression

737− (unsafeVariadicFunction "json_populate_record_set"

738− (nullRow tableName :* expr :* Nil) `As` alias)

739−

740−-- | Expands the outermost array of objects in the given binary JSON expression

741−-- to a set of rows whose columns match the record type defined by the given

742−-- table.

743−jsonbPopulateRecordSetAs

744− :: (KnownSymbol alias, Has tab schema ('Table table))

745− => Alias tab

746− -> Expression schema '[] 'Ungrouped params (nullity 'PGjsonb)

747− -> Alias alias

748− -> FromClause schema params '[alias ::: TableToRelation table]

749−jsonbPopulateRecordSetAs tableName expr alias = unsafeAliasedFromClauseExpression

750− (unsafeVariadicFunction "jsonb_populate_record_set"

751− (nullRow tableName :* expr :* Nil) `As` alias)

752−

753−renderTableTypeExpression

754− :: All Top types

755− => Aliased (NP (Aliased (TypeExpression schema))) (tab ::: types)

756− -> ByteString

757−renderTableTypeExpression (hc `As` tab)

758− = (renderAlias tab <>)

759− . parenthesized

760− . commaSeparated

761− . flip appEndo []

762− . hcfoldMap

763− (Proxy :: Proxy Top)

764− (\(ty `As` name) -> Endo

765− ((renderAlias name <+> renderTypeExpression ty):))

766− $ hc

767−

768−unsafeTableAliasedFromClauseExpression

769− :: All Top types

770− => Expression schema' relations' grouping' params' ty'

771− -> Aliased (NP (Aliased (TypeExpression schema))) (tab ::: types)

772− -> FromClause schema params '[alias ::: types]

773−unsafeTableAliasedFromClauseExpression expr types = UnsafeFromClause

774− (renderExpression expr

775− <+> "AS"

776− <+> renderTableTypeExpression types)

777−

778−-- | Builds an arbitrary record from a JSON object. As with all functions

779−-- returning record, the caller must explicitly define the structure of the

780−-- record with an AS clause.

781−jsonToRecordAs

782− :: All Top types

783− => Expression schema '[] 'Ungrouped params (nullity 'PGjson)

784− -> Aliased (NP (Aliased (TypeExpression schema))) (tab ::: types)

785− -> FromClause schema params '[tab ::: types]

786−jsonToRecordAs expr types =

787− unsafeTableAliasedFromClauseExpression

788− (unsafeFunction "json_to_record" expr)

789− types

790−

791−-- | Builds an arbitrary record from a binary JSON object. As with all functions

792−-- returning record, the caller must explicitly define the structure of the

793−-- record with an AS clause.

794−jsonbToRecordAs

795− :: All Top types

796− => Expression schema '[] 'Ungrouped params (nullity 'PGjsonb)

797− -> Aliased (NP (Aliased (TypeExpression schema))) (tab ::: types)

798− -> FromClause schema params '[tab ::: types]

799−jsonbToRecordAs expr types =

800− unsafeTableAliasedFromClauseExpression

801− (unsafeFunction "jsonb_to_record" expr)

802− types

803−

804−-- | Builds an arbitrary set of records from a JSON array of objects (see note

805−-- below). As with all functions returning record, the caller must explicitly

806−-- define the structure of the record with an AS clause.

807−jsonToRecordSetAs

808− :: All Top types

809− => Expression schema '[] 'Ungrouped params (nullity 'PGjson)

810− -> Aliased (NP (Aliased (TypeExpression schema))) (tab ::: types)

811− -> FromClause schema params '[tab ::: types]

812−jsonToRecordSetAs expr types =

813− unsafeTableAliasedFromClauseExpression

814− (unsafeFunction "json_to_recordset" expr)

815− types

816−

817−-- | Builds an arbitrary set of records from a binary JSON array of objects (see

818−-- note below). As with all functions returning record, the caller must

819−-- explicitly define the structure of the record with an AS clause.

820−jsonbToRecordSetAs

821− :: All Top types

822− => Expression schema '[] 'Ungrouped params (nullity 'PGjsonb)

823− -> Aliased (NP (Aliased (TypeExpression schema))) (tab ::: types)

824− -> FromClause schema params '[tab ::: types]

825−jsonbToRecordSetAs expr types =

826− unsafeTableAliasedFromClauseExpression

827− (unsafeFunction "jsonb_to_recordset" expr)

828− types

829−

830816{-----------------------------------------

831817FROM clauses

832818-----------------------------------------}

@@ -835,61 +821,76 @@ FROM clauses

835821A `FromClause` can be a table name, or a derived table such

836822as a subquery, a @JOIN@ construct, or complex combinations of these.

837823-}

838−newtype FromClause schema params relations

824+newtype FromClause outer commons schemas params from

839825 = UnsafeFromClause { renderFromClause :: ByteString }

840826 deriving (GHC.Generic,Show,Eq,Ord,NFData)

827+instance RenderSQL (FromClause outer commons schemas params from) where

828+ renderSQL = renderFromClause

841829

842−-- | A real `table` is a table from the schema.

830+-- | A real `table` is a table from the database.

843831table

844− :: Has tab schema ('Table table)

845− => Aliased Alias (alias ::: tab)

846− -> FromClause schema params '[alias ::: TableToRelation table]

832+ :: (Has sch schemas schema, Has tab schema ('Table table))

833+ => Aliased (QualifiedAlias sch) (alias ::: tab)

834+ -> FromClause outer commons schemas params '[alias ::: TableToRow table]

847835table (tab `As` alias) = UnsafeFromClause $

848− renderAlias tab <+> "AS" <+> renderAlias alias

836+ renderSQL tab <+> "AS" <+> renderSQL alias

849837

850838-- | `subquery` derives a table from a `Query`.

851839subquery

852− :: Aliased (Query schema params) rel

853− -> FromClause schema params '[rel]

854−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)

855843

856844-- | `view` derives a table from a `View`.

857845view

858− :: Has view schema ('View rel)

859− => Aliased Alias (alias ::: view)

860− -> FromClause schema params '[alias ::: rel]

846+ :: (Has sch schemas schema, Has vw schema ('View view))

847+ => Aliased (QualifiedAlias sch) (alias ::: vw)

848+ -> FromClause outer commons schemas params '[alias ::: view]

861849view (vw `As` alias) = UnsafeFromClause $

862− 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

863863

864−{- | @left & crossJoin right@. For every possible combination of rows from

865− @left@ and @right@ (i.e., a Cartesian product), the joined table will contain

866− a row consisting of all columns in @left@ followed by all columns in @right@.

867− If the tables have @n@ and @m@ rows respectively, the joined table will

868− 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.

869870-}

870871crossJoin

871− :: FromClause schema params right

872+ :: FromClause outer commons schemas params right

872873 -- ^ right

873− -> FromClause schema params left

874+ -> FromClause outer commons schemas params left

874875 -- ^ left

875− -> FromClause schema params (Join left right)

876+ -> FromClause outer commons schemas params (Join left right)

876877crossJoin right left = UnsafeFromClause $

877− renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right

878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right

878879

879880{- | @left & innerJoin right on@. The joined table is filtered by

880881the @on@ condition.

881882-}

882883innerJoin

883− :: FromClause schema params right

884+ :: FromClause outer commons schemas params right

884885 -- ^ right

885− -> Condition schema (Join left right) 'Ungrouped params

886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

886887 -- ^ @on@ condition

887− -> FromClause schema params left

888+ -> FromClause outer commons schemas params left

888889 -- ^ left

889− -> FromClause schema params (Join left right)

890+ -> FromClause outer commons schemas params (Join left right)

890891innerJoin right on left = UnsafeFromClause $

891− renderFromClause left <+> "INNER JOIN" <+> renderFromClause right

892− <+> "ON" <+> renderExpression on

892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right

893+ <+> "ON" <+> renderSQL on

893894

894895{- | @left & leftOuterJoin right on@. First, an inner join is performed.

895896 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -897,16 +898,16 @@ innerJoin right on left = UnsafeFromClause $

897898 Thus, the joined table always has at least one row for each row in @left@.

898899-}

899900leftOuterJoin

900− :: FromClause schema params right

901+ :: FromClause outer commons schemas params right

901902 -- ^ right

902− -> Condition schema (Join left right) 'Ungrouped params

903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

903904 -- ^ @on@ condition

904− -> FromClause schema params left

905+ -> FromClause outer commons schemas params left

905906 -- ^ left

906− -> FromClause schema params (Join left (NullifyRelations right))

907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))

907908leftOuterJoin right on left = UnsafeFromClause $

908− renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right

909− <+> "ON" <+> renderExpression on

909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right

910+ <+> "ON" <+> renderSQL on

910911

911912{- | @left & rightOuterJoin right on@. First, an inner join is performed.

912913 Then, for each row in @right@ that does not satisfy the @on@ condition with

@@ -915,16 +916,16 @@ leftOuterJoin right on left = UnsafeFromClause $

915916 have a row for each row in @right@.

916917-}

917918rightOuterJoin

918− :: FromClause schema params right

919+ :: FromClause outer commons schemas params right

919920 -- ^ right

920− -> Condition schema (Join left right) 'Ungrouped params

921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

921922 -- ^ @on@ condition

922− -> FromClause schema params left

923+ -> FromClause outer commons schemas params left

923924 -- ^ left

924− -> FromClause schema params (Join (NullifyRelations left) right)

925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)

925926rightOuterJoin right on left = UnsafeFromClause $

926− renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right

927− <+> "ON" <+> renderExpression on

927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right

928+ <+> "ON" <+> renderSQL on

928929

929930{- | @left & fullOuterJoin right on@. First, an inner join is performed.

930931 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -934,42 +935,46 @@ rightOuterJoin right on left = UnsafeFromClause $

934935 is added.

935936-}

936937fullOuterJoin

937− :: FromClause schema params right

938+ :: FromClause outer commons schemas params right

938939 -- ^ right

939− -> Condition schema (Join left right) 'Ungrouped params

940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

940941 -- ^ @on@ condition

941− -> FromClause schema params left

942+ -> FromClause outer commons schemas params left

942943 -- ^ left

943− -> FromClause schema params

944− (Join (NullifyRelations left) (NullifyRelations right))

944+ -> FromClause outer commons schemas params

945+ (Join (NullifyFrom left) (NullifyFrom right))

945946fullOuterJoin right on left = UnsafeFromClause $

946− renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right

947− <+> "ON" <+> renderExpression on

947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right

948+ <+> "ON" <+> renderSQL on

948949

949950{-----------------------------------------

950951Grouping

951952-----------------------------------------}

952953

953−-- | `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

954955-- used to group together those rows in a table that have the same values

955956-- in all the columns listed. @By \#col@ will reference an unambiguous

956957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

957958-- qualified column @tab.col@.

958959data By

959− (relations :: RelationsType)

960+ (from :: FromType)

960961 (by :: (Symbol,Symbol)) where

961962 By1

962− :: (HasUnique relation relations columns, Has column columns ty)

963+ :: (HasUnique table from columns, Has column columns ty)

963964 => Alias column

964− -> By relations '(relation, column)

965+ -> By from '(table, column)

965966 By2

966− :: (Has relation relations columns, Has column columns ty)

967− => Alias relation

967+ :: (Has table from columns, Has column columns ty)

968+ => Alias table

968969 -> Alias column

969− -> By relations '(relation, column)

970−deriving instance Show (By relations by)

971−deriving instance Eq (By relations by)

972−deriving instance Ord (By relations by)

970+ -> By from '(table, column)

971+deriving instance Show (By from by)

972+deriving instance Eq (By from by)

973+deriving instance Ord (By from by)

974+instance RenderSQL (By from by) where

975+ renderSQL = \case

976+ By1 column -> renderSQL column

977+ By2 rel column -> renderSQL rel <> "." <> renderSQL column

973978

974979instance (HasUnique rel rels cols, Has col cols ty, by ~ '(rel, col))

975980 => IsLabel col (By rels by) where fromLabel = By1 fromLabel

@@ -981,94 +986,113 @@ instance (Has rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

981986 => IsQualified rel col (NP (By rels) bys) where

982987 rel ! col = By2 rel col :* Nil

983988

984−-- | Renders a `By`.

985−renderBy :: By relations by -> ByteString

986−renderBy = \case

987− By1 column -> renderAlias column

988− By2 rel column -> renderAlias rel <> "." <> renderAlias column

989−

990989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

991990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

992991-- @NoGroups@ is distinguised from @Group Nil@ since no aggregation can be

993992-- done on @NoGroups@ while all output `Expression`s must be aggregated

994993-- in @Group Nil@. In general, all output `Expression`s in the

995994-- complement of @bys@ must be aggregated in @Group bys@.

996−data GroupByClause relations grouping where

997− NoGroups :: GroupByClause relations 'Ungrouped

998− Group

999− :: SListI bys

1000− => NP (By relations) bys

1001− -> GroupByClause relations ('Grouped bys)

1002−

1003−-- | Renders a `GroupByClause`.

1004−renderGroupByClause :: GroupByClause relations grouping -> ByteString

1005−renderGroupByClause = \case

1006− NoGroups -> ""

1007− Group Nil -> ""

1008− 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'

10091009

10101010-- | A `HavingClause` is used to eliminate groups that are not of interest.

10111011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

10121012-- `TableExpression` must use `Having` whose conditions are combined with

10131013-- `.&&`.

1014−data HavingClause schema relations grouping params where

1015− NoHaving :: HavingClause schema relations 'Ungrouped params

1014+data HavingClause outer commons grp schemas params from where

1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from

10161016 Having

1017− :: [Condition schema relations ('Grouped bys) params]

1018− -> HavingClause schema relations ('Grouped bys) params

1019−deriving instance Show (HavingClause schema relations grouping params)

1020−deriving instance Eq (HavingClause schema relations grouping params)

1021−deriving instance Ord (HavingClause schema relations grouping params)

1017+ :: [Condition outer commons ('Grouped bys) schemas params from]

1018+ -> HavingClause outer commons ('Grouped bys) schemas params from

1019+deriving instance Show (HavingClause outer commons grp schemas params from)

1020+deriving instance Eq (HavingClause outer commons grp schemas params from)

1021+deriving instance Ord (HavingClause outer commons grp schemas params from)

10221022

10231023-- | Render a `HavingClause`.

1024−renderHavingClause :: HavingClause schema relations grouping params -> ByteString

1025−renderHavingClause = \case

1026− NoHaving -> ""

1027− Having [] -> ""

1028− Having conditions ->

1029− " HAVING" <+> commaSeparated (renderExpression <$> conditions)

1030−

1031−{-----------------------------------------

1032−Sorting

1033−-----------------------------------------}

1024+instance RenderSQL (HavingClause outer commons grp schemas params from) where

1025+ renderSQL = \case

1026+ NoHaving -> ""

1027+ Having [] -> ""

1028+ Having conditions ->

1029+ " HAVING" <+> commaSeparated (renderSQL <$> conditions)

1030+

1031+-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.

1032+data CommonTableExpression statement

1033+ (schemas :: SchemasType)

1034+ (params :: [NullityType])

1035+ (commons0 :: FromType)

1036+ (commons1 :: FromType) where

1037+ CommonTableExpression

1038+ :: Aliased (statement commons schemas params) (cte ::: common)

1039+ -> CommonTableExpression statement schemas params commons (cte ::: common ': commons)

1040+instance

1041+ ( KnownSymbol cte

1042+ , commons1 ~ (cte ::: common ': commons)

1043+ ) => Aliasable cte

1044+ (statement commons schemas params common)

1045+ (CommonTableExpression statement schemas params commons commons1) where

1046+ statement `as` cte = CommonTableExpression (statement `as` cte)

1047+instance

1048+ ( KnownSymbol cte

1049+ , commons1 ~ (cte ::: common ': commons)

1050+ ) => Aliasable cte

1051+ (statement commons schemas params common)

1052+ (Path (CommonTableExpression statement schemas params) commons commons1) where

1053+ statement `as` cte = csingleton (statement `as` cte)

1054+

1055+instance (forall c s p r. RenderSQL (statement c s p r)) => RenderSQL

1056+ (CommonTableExpression statement schemas params commons0 commons1) where

1057+ renderSQL (CommonTableExpression (statement `As` cte)) =

1058+ renderSQL cte <+> "AS" <+> parenthesized (renderSQL statement)

1059+

1060+-- | `with` provides a way to write auxiliary statements for use in a larger query.

1061+-- These statements, referred to as `CommonTableExpression`s, can be thought of as

1062+-- defining temporary tables that exist just for one query.

1063+class With statement where

1064+ with

1065+ :: Path (CommonTableExpression statement schemas params) commons0 commons1

1066+ -- ^ common table expressions

1067+ -> statement commons1 schemas params row

1068+ -- ^ larger query

1069+ -> statement commons0 schemas params row

1070+instance With (Query outer) where

1071+ with Done query = query

1072+ with ctes query = UnsafeQuery $

1073+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL query

10341074

1035−-- | `SortExpression`s are used by `sortBy` to optionally sort the results

1036−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result

1037−-- column to ascending or descending. Ascending order puts smaller values

1038−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,

1039−-- descending order is determined with the `.>` operator. `AscNullsFirst`,

1040−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

1041−-- determine whether nulls appear before or after non-null values in the sort

1042−-- ordering of a `Null` result column.

1043−data SortExpression schema relations grouping params where

1044− Asc

1045− :: Expression schema relations grouping params ('NotNull ty)

1046− -> SortExpression schema relations grouping params

1047− Desc

1048− :: Expression schema relations grouping params ('NotNull ty)

1049− -> SortExpression schema relations grouping params

1050− AscNullsFirst

1051− :: Expression schema relations grouping params ('Null ty)

1052− -> SortExpression schema relations grouping params

1053− AscNullsLast

1054− :: Expression schema relations grouping params ('Null ty)

1055− -> SortExpression schema relations grouping params

1056− DescNullsFirst

1057− :: Expression schema relations grouping params ('Null ty)

1058− -> SortExpression schema relations grouping params

1059− DescNullsLast

1060− :: Expression schema relations grouping params ('Null ty)

1061− -> SortExpression schema relations grouping params

1062−deriving instance Show (SortExpression schema relations grouping params)

1063−

1064−-- | Render a `SortExpression`.

1065−renderSortExpression :: SortExpression schema relations grouping params -> ByteString

1066−renderSortExpression = \case

1067− Asc expression -> renderExpression expression <+> "ASC"

1068− Desc expression -> renderExpression expression <+> "DESC"

1069− AscNullsFirst expression -> renderExpression expression

1070− <+> "ASC NULLS FIRST"

1071− DescNullsFirst expression -> renderExpression expression

1072− <+> "DESC NULLS FIRST"

1073− AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"

1074− DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"

1075+{- |

1076+>>> import Data.Monoid (Sum (..))

1077+>>> import Data.Int (Int64)

1078+>>> :{

1079+ let

1080+ query :: Query_ schema () (Sum Int64)

1081+ query = withRecursive

1082+ ( values_ ((1 & astype int) `as` #n)

1083+ `unionAll`

1084+ select_ ((#n + 1) `as` #n)

1085+ (from (common #t) & where_ (#n .< 100)) `as` #t )

1086+ ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))

1087+ in printSQL query

1088+:}

1089+WITH RECURSIVE "t" AS ((SELECT * FROM (VALUES ((1 :: int))) AS t ("n")) UNION ALL (SELECT ("n" + 1) AS "n" FROM "t" AS "t" WHERE ("n" < 100))) SELECT COALESCE(sum(ALL "n"), 0) AS "getSum" FROM "t" AS "t"

1090+-}

1091+withRecursive

1092+ :: Aliased (Query outer (recursive ': commons) schemas params) recursive

1093+ -> Query outer (recursive ': commons) schemas params row

1094+ -> Query outer commons schemas params row

1095+withRecursive (recursive `As` cte) query = UnsafeQuery $

1096+ "WITH RECURSIVE" <+> renderSQL cte

1097+ <+> "AS" <+> parenthesized (renderSQL recursive)

1098+ <+> renderSQL query

squeal-postgresql/src/Squeal/PostgreSQL/Render.hs+48−14

@@ -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

@@ -52,8 +58,13 @@ 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

67+infixr 7 <+>

5768str1 <+> str2 = str1 <> " " <> str2

5869

5970-- | Comma separate a list of `ByteString`s.

@@ -66,11 +77,12 @@ doubleQuoted str = "\"" <> str <> "\""

6677

6778-- | Add single quotes around a `Text` and escape single quotes within it.

6879singleQuotedText :: Text -> ByteString

69−singleQuotedText str = "'" <> T.encodeUtf8 (T.replace "'" "''" str) <> "'"

80+singleQuotedText str =

81+ "'" <> Text.encodeUtf8 (Text.replace "'" "''" str) <> "'"

7082

7183-- | Add single quotes around a `ByteString` and escape single quotes within it.

7284singleQuotedUtf8 :: ByteString -> ByteString

73−singleQuotedUtf8 = singleQuotedText . T.decodeUtf8

85+singleQuotedUtf8 = singleQuotedText . Text.decodeUtf8

7486

7587-- | Comma separate the renderings of a heterogeneous list.

7688renderCommaSeparated

@@ -82,6 +94,16 @@ renderCommaSeparated render

8294 . hcollapse

8395 . hmap (K . render)

8496

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+

85107-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

86108-- `Nothing`s.

87109renderCommaSeparatedMaybe

@@ -103,9 +125,21 @@ renderSymbol :: forall s. KnownSymbol s => ByteString

103125renderSymbol = fromString (symbolVal' (proxy# :: Proxy# s))

104126

105127-- | A class for rendering SQL

106−class RenderSQL sql where

107− renderSQL :: sql -> ByteString

128+class RenderSQL sql where renderSQL :: sql -> ByteString

108129

109130-- | Print SQL.

110−printSQL :: (RenderSQL sql, MonadBase IO io) => sql -> io ()

111−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+310−520

@@ -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

@@ -20,7 +19,9 @@ it defines an embedding of Haskell types into Postgres types.

2019 , FlexibleInstances

2120 , FunctionalDependencies

2221 , GADTs

22+ , LambdaCase

2323 , OverloadedStrings

24+ , QuantifiedConstraints

2425 , RankNTypes

2526 , ScopedTypeVariables

2627 , StandaloneDeriving

@@ -33,125 +34,85 @@ it defines an embedding of Haskell types into Postgres types.

3334#-}

3435

3536module Squeal.PostgreSQL.Schema

36− ( -- * Types

37+ ( -- * Postgres Types

3738 PGType (..)

38− , HasOid (..)

3939 , NullityType (..)

40+ , RowType

41+ , FromType

42+ -- * Schema Types

4043 , ColumnType

41− -- * Tables

4244 , ColumnsType

43− , RelationType

44− , NilRelation

45− , RelationsType

4645 , TableType

47− -- * Schema

4846 , SchemumType (..)

47+ , IndexType (..)

48+ , FunctionType

49+ , OperatorType (..)

50+ , ReturnsType (..)

4951 , SchemaType

52+ , SchemasType

53+ , Public

5054 -- * Constraints

5155 , (:=>)

5256 , ColumnConstraint (..)

5357 , TableConstraint (..)

5458 , TableConstraints

55− , NilTableConstraints

5659 , Uniquely

57− -- * Aliases

58− , (:::)

59− , Alias (Alias)

60− , renderAlias

61− , renderAliases

62− , Aliased (As)

63− , Aliasable (as)

64− , renderAliasedAs

65− , AliasesOf

66− , Has

67− , HasUnique

68− , HasAll

69− , IsLabel (..)

70− , IsQualified (..)

71− , renderAliasString

7260 -- * Enumerated Labels

7361 , IsPGlabel (..)

7462 , PGlabel (..)

75− , renderLabel

76− , renderLabels

77− -- * Grouping

78− , Grouping (..)

79− , GroupedBy

80− -- * Type Families

81− , Join

82− , With

63+ -- * Data Definitions

8364 , Create

65+ , CreateIfNotExists

66+ , CreateOrReplace

8467 , Drop

68+ , DropSchemum

69+ , DropIfExists

70+ , DropSchemumIfExists

8571 , Alter

72+ , AlterIfExists

8673 , Rename

87− , Elem

88− , In

89− , Length

74+ , RenameIfExists

75+ , ConstraintInvolves

76+ , DropIfConstraintsInvolve

77+ , IsNotElem

78+ , AllUnique

79+ -- * Type Classifications

9080 , PGNum

9181 , PGIntegral

9282 , PGFloating

9383 , PGTypeOf

94− , PGarrayOf

95− , PGarray

96− , PGtextArray

97− , SameTypes

84+ , PGJsonType

85+ , PGJsonKey

9886 , SamePGType

9987 , AllNotNull

10088 , NotAllNull

89+ -- * Nullifications

10190 , NullifyType

102− , NullifyRelation

103− , NullifyRelations

104− , ColumnsToRelation

91+ , NullifyRow

92+ , NullifyFrom

93+ -- * Table Conversions

10594 , TableToColumns

106− , TableToRelation

107− , RelationToNullityTypes

108− , ConstraintInvolves

109− , DropIfConstraintsInvolve

110− -- ** JSON support

111− , PGjson_

112− , PGjsonKey

113− -- * Embedding

114− , PG

115− , EnumFrom

116− , LabelsFrom

117− , CompositeFrom

118− , PGFieldsFrom

119− , PGFieldsOf

120− , PGFieldOf

121− , ConstructorsOf

122− , ConstructorNameOf

123− , ConstructorNamesOf

95+ , ColumnsToRow

96+ , TableToRow

12497 ) where

12598

126−import Control.DeepSeq

127−import Data.Aeson (Value)

128−import Data.ByteString (ByteString)

129−import Data.Int (Int16, Int32, Int64)

99+import Control.Category

130100import Data.Kind

131101import Data.Monoid hiding (All)

132−import Data.Scientific (Scientific)

133−import Data.String

134−import Data.Text (Text)

135−import Data.Time

136−import Data.Word (Word16, Word32, Word64)

137102import Data.Type.Bool

138−import Data.UUID.Types (UUID)

139103import Generics.SOP

140−import Generics.SOP.Record

141−import GHC.OverloadedLabels

142104import GHC.TypeLits

143−import Network.IP.Addr

144−

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

105+import Prelude hiding (id, (.))

149106

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.

182− | PGcomposite [(Symbol, NullityType)] -- ^ a composite type represents the structure of a row or record; it is essentially just a list of field names and their data types.

144+ | PGcomposite RowType -- ^ a composite type represents the structure of a row or record; it is essentially just a list of field names and their data types.

145+ | PGtsvector -- ^ A tsvector value is a sorted list of distinct lexemes, which are words that have been normalized to merge different variants of the same word.

146+ | PGtsquery -- ^ A tsquery value stores lexemes that are to be searched for.

147+ | PGoid -- Object identifiers (OIDs) are used internally by PostgreSQL as primary keys for various system tables.

148+ | PGrange PGType -- ^ Range types are data types representing a range of values of some element type (called the range's subtype).

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

@@ -274,11 +207,14 @@ 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)]

279−-- | A monokinded empty `TableConstraints`.

280−type family NilTableConstraints :: TableConstraints where

281− NilTableConstraints = '[]

282218

283219-- | A `ForeignKey` must reference columns that either are

284220-- a `PrimaryKey` or form a `Unique` constraint.

@@ -302,248 +238,64 @@ type family Uniquely

302238-- :}

303239type TableType = (TableConstraints,ColumnsType)

304240

305−-- | `RelationType` is a row of `NullityType`

306−--

307−-- >>> :{

308−-- type family PersonRelation :: RelationType where

309−-- PersonRelation =

310−-- '[ "name" ::: 'NotNull 'PGtext

311−-- , "age" ::: 'NotNull 'PGint4

312−-- , "dateOfBirth" ::: 'Null 'PGdate

313−-- ]

314−-- :}

315−type RelationType = [(Symbol,NullityType)]

316−-- | A monokinded empty `RelationType`.

317−type family NilRelation :: RelationType where NilRelation = '[]

318−

319−-- | `RelationsType` is a row of `RelationType`s, thought of as a product.

320−type RelationsType = [(Symbol,RelationType)]

241+{- | A `RowType` is a row of `NullityType`. They correspond to Haskell

242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.

243+

244+>>> :{

245+type family PersonRow :: RowType where

246+ PersonRow =

247+ '[ "name" ::: 'NotNull 'PGtext

248+ , "age" ::: 'NotNull 'PGint4

249+ , "dateOfBirth" ::: 'Null 'PGdate

250+ ]

251+:}

252+-}

253+type RowType = [(Symbol,NullityType)]

321254

322−-- | `ColumnsToRelation` removes column constraints.

323−type family ColumnsToRelation (columns :: ColumnsType) :: RelationType where

324− ColumnsToRelation '[] = '[]

325− ColumnsToRelation (column ::: constraint :=> ty ': columns) =

326− column ::: ty ': ColumnsToRelation columns

255+{- | `FromType` is a row of `RowType`s. It can be thought of as

256+a product, or horizontal gluing and is used in `Squeal.PostgreSQL.Query.FromClause`s

257+and `Squeal.PostgreSQL.Query.TableExpression`s.

258+-}

259+type FromType = [(Symbol,RowType)]

260+

261+-- | `ColumnsToRow` removes column constraints.

262+type family ColumnsToRow (columns :: ColumnsType) :: RowType where

263+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': column5 ::: _ :=> ty5 ': columns) =

264+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': ColumnsToRow columns

265+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': columns) =

266+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': ColumnsToRow columns

267+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': columns) =

268+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': ColumnsToRow columns

269+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': columns) =

270+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': ColumnsToRow columns

271+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': columns) =

272+ column ::: ty ': column1 ::: ty1 ': ColumnsToRow columns

273+ ColumnsToRow (column ::: _ :=> ty ': columns) =

274+ column ::: ty ': ColumnsToRow columns

275+ ColumnsToRow '[] = '[]

327276

328277-- | `TableToColumns` removes table constraints.

329278type family TableToColumns (table :: TableType) :: ColumnsType where

330279 TableToColumns (constraints :=> columns) = columns

331280

332−-- | Convert a table to a relation.

333−type family TableToRelation (table :: TableType) :: RelationType where

334− TableToRelation tab = ColumnsToRelation (TableToColumns tab)

281+-- | Convert a table to a row type.

282+type family TableToRow (table :: TableType) :: RowType where

283+ TableToRow tab = ColumnsToRow (TableToColumns tab)

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

285+-- | Numeric Postgres types.

286+type PGNum =

287+ '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

342288

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 relation, KnownSymbol column)

348− => GroupedBy relation column bys where

349−instance {-# OVERLAPPING #-} (KnownSymbol relation, KnownSymbol column)

350− => GroupedBy relation column ('(table,column) ': bys)

351−instance {-# OVERLAPPABLE #-}

352− ( KnownSymbol relation

353− , KnownSymbol column

354− , GroupedBy relation column bys

355− ) => GroupedBy relation 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 (alias ~ alias1, KnownSymbol alias) => 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−-- | `AliasesOf` retains the AliasesOf in a row.

438−type family AliasesOf aliaseds where

439− AliasesOf '[] = '[]

440− AliasesOf (alias ::: ty ': tys) = alias ': AliasesOf tys

441−

442−-- | @HasUnique alias fields field@ is a constraint that proves that

443−-- @fields@ is a singleton of @alias ::: field@.

444−type HasUnique alias fields field = fields ~ '[alias ::: field]

445−

446−-- | @Has alias fields field@ is a constraint that proves that

447−-- @fields@ has a field of @alias ::: field@, inferring @field@

448−-- from @alias@ and @fields@.

449−class KnownSymbol alias =>

450− Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)

451− | alias fields -> field where

452−instance {-# OVERLAPPING #-} KnownSymbol alias

453− => Has alias (alias ::: field ': fields) field

454−instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)

455− => Has alias (field' ': fields) field

456−

457−-- | `HasAll` extends `Has` to take lists of @aliases@ and @fields@ and infer

458−-- a list of @subfields@.

459−class

460− ( All KnownSymbol aliases

461− ) => HasAll

462− (aliases :: [Symbol])

463− (fields :: [(Symbol,kind)])

464− (subfields :: [(Symbol,kind)])

465− | aliases fields -> subfields where

466−instance {-# OVERLAPPING #-} HasAll '[] fields '[]

467−instance {-# OVERLAPPABLE #-}

468− (Has alias fields field, HasAll aliases fields subfields)

469− => HasAll (alias ': aliases) fields (alias ::: field ': subfields)

470−

471−-- | Analagous to `IsLabel`, the constraint

472−-- `IsQualified` defines `!` for a column alias qualified

473−-- by a table alias.

474−class IsQualified table column expression where

475− (!) :: Alias table -> Alias column -> expression

476− infixl 9 !

477−instance IsQualified table column (Alias table, Alias column) where (!) = (,)

478−

479−-- | @Elem@ is a promoted `Data.List.elem`.

480−type family Elem x xs where

481− Elem x '[] = 'False

482− Elem x (x ': xs) = 'True

483− Elem x (_ ': xs) = Elem x xs

484−

485−-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.

486−type family In x xs :: Constraint where In x xs = Elem x xs ~ 'True

487−

488−-- | `PGNum` is a constraint on `PGType` whose

489−-- `Squeal.PostgreSQL.Expression.Expression`s have a `Num` constraint.

490−type PGNum ty =

491− In ty '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

492−

493−-- | `PGFloating` is a constraint on `PGType` whose

494−-- `Squeal.PostgreSQL.Expression.Expression`s

495−-- have `Fractional` and `Floating` constraints.

496−type PGFloating ty = In ty '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

497−

498−-- | `PGIntegral` is a constraint on `PGType` whose

499−-- `Squeal.PostgreSQL.Expression.Expression`s

500−-- have `Squeal.PostgreSQL.Expression.div_` and

501−-- `Squeal.PostgreSQL.Expression.mod_` functions.

502−type PGIntegral ty = In ty '[ 'PGint2, 'PGint4, 'PGint8]

503−

504−-- | Error message helper for displaying unavailable\/unknown\/placeholder type

505−-- variables whose kind is known.

506−type Placeholder k = 'Text "(_::" :<>: 'ShowType k :<>: 'Text ")"

507−

508−type ErrArrayOf arr ty = arr :<>: 'Text " " :<>: ty

509−type ErrPGfixarrayOf t = ErrArrayOf ('ShowType 'PGfixarray :<>: 'Text " " :<>: Placeholder Nat) t

510−type ErrPGvararrayOf t = ErrArrayOf ('ShowType 'PGvararray) t

511−

512−-- | Ensure a type is a valid array type.

513−type family PGarray name arr :: Constraint where

514− PGarray name ('PGvararray x) = ()

515− PGarray name ('PGfixarray n x) = ()

516− PGarray name val = TypeError

517− ('Text name :<>: 'Text ": Unsatisfied PGarray constraint. Expected either: "

518− :$$: 'Text " • " :<>: ErrPGvararrayOf (Placeholder PGType)

519− :$$: 'Text " • " :<>: ErrPGfixarrayOf (Placeholder PGType)

520− :$$: 'Text "But got: " :<>: 'ShowType val)

521−

522−-- | Ensure a type is a valid array type with a specific element type.

523−type family PGarrayOf name arr ty :: Constraint where

524− PGarrayOf name ('PGvararray x) ty = x ~ ty

525− PGarrayOf name ('PGfixarray n x) ty = x ~ ty

526− PGarrayOf name val ty = TypeError

527− ( 'Text name :<>: 'Text "Unsatisfied PGarrayOf constraint. Expected either: "

528− :$$: 'Text " • " :<>: ErrPGvararrayOf ( 'ShowType ty )

529− :$$: 'Text " • " :<>: ErrPGfixarrayOf ( 'ShowType ty )

530− :$$: 'Text "But got: " :<>: 'ShowType val)

531−

532−-- | Ensure a type is a valid array type whose elements are text.

533−type PGtextArray name arr = PGarrayOf name arr ('NotNull 'PGtext)

289+-- | Floating Postgres types.

290+type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

291+

292+-- | Integral Postgres types.

293+type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]

534294

535295-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

536296type family PGTypeOf (ty :: NullityType) :: PGType where

537297 PGTypeOf (nullity pg) = pg

538298

539−-- | `SameTypes` is a constraint that proves two `ColumnsType`s have the same

540−-- length and the same `ColumnType`s.

541−type family SameTypes (columns0 :: ColumnsType) (columns1 :: ColumnsType)

542− :: Constraint where

543− SameTypes '[] '[] = ()

544− SameTypes (column0 ::: def0 :=> ty0 ': columns0) (column1 ::: def1 :=> ty1 ': columns1)

545− = (ty0 ~ ty1, SameTypes columns0 columns1)

546−

547299-- | Equality constraint on the underlying `PGType` of two columns.

548300class SamePGType

549301 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where

@@ -553,44 +305,63 @@ instance ty0 ~ ty1 => SamePGType

553305

554306-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.

555307type 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

556314 AllNotNull '[] = ()

557− AllNotNull (column ::: def :=> 'NotNull ty ': columns) = AllNotNull columns

558315

559316-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

560317-- @NOT NULL@.

561318type family NotAllNull (columns :: ColumnsType) :: Constraint where

562− NotAllNull (column ::: def :=> 'NotNull ty ': columns) = ()

563− NotAllNull (column ::: def :=> 'Null ty ': columns) = NotAllNull columns

564−

565−-- | `NullifyType` is an idempotent that nullifies a `ColumnType`.

319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

322+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

323+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

324+ NotAllNull (_ ::: _ :=> 'NotNull _ ': _) = ()

325+ NotAllNull (_ ::: _ :=> 'Null _ ': columns) = NotAllNull columns

326+

327+-- | `NullifyType` is an idempotent that nullifies a `NullityType`.

566328type family NullifyType (ty :: NullityType) :: NullityType where

567329 NullifyType ('Null ty) = 'Null ty

568330 NullifyType ('NotNull ty) = 'Null ty

569331

570−-- | `NullifyRelation` is an idempotent that nullifies a `ColumnsType`.

571−type family NullifyRelation (columns :: RelationType) :: RelationType where

572− NullifyRelation '[] = '[]

573− NullifyRelation (column ::: ty ': columns) =

574− column ::: NullifyType ty ': NullifyRelation columns

575−

576−-- | `NullifyRelations` is an idempotent that nullifies a `RelationsType`

332+-- | `NullifyRow` is an idempotent that nullifies a `RowType`.

333+type family NullifyRow (columns :: RowType) :: RowType where

334+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': columns) =

335+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': column5 ::: NullifyType ty5 ': NullifyRow columns

336+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': columns) =

337+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': NullifyRow columns

338+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': columns) =

339+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': NullifyRow columns

340+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': columns) =

341+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': NullifyRow columns

342+ NullifyRow (column ::: ty ': column1 ::: ty1 ': columns) =

343+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': NullifyRow columns

344+ NullifyRow (column ::: ty ': columns) =

345+ column ::: NullifyType ty ': NullifyRow columns

346+ NullifyRow '[] = '[]

347+

348+-- | `NullifyFrom` is an idempotent that nullifies a `FromType`

577349-- used to nullify the left or right hand side of an outer join

578350-- in a `Squeal.PostgreSQL.Query.FromClause`.

579−type family NullifyRelations (tables :: RelationsType) :: RelationsType where

580− NullifyRelations '[] = '[]

581− NullifyRelations (table ::: columns ': tables) =

582− table ::: NullifyRelation columns ': NullifyRelations tables

583−

584−-- | `RelationToNullityTypes` drops the column constraints.

585−type family RelationToNullityTypes (rel :: RelationType) :: [NullityType] where

586− RelationToNullityTypes ('(k, x) : xs) = x : RelationToNullityTypes xs

587− RelationToNullityTypes '[] = '[]

588−

589−-- | `Join` is simply promoted `++` and is used in @JOIN@s in

590−-- `Squeal.PostgreSQL.Query.FromClause`s.

591−type family Join xs ys where

592− Join '[] ys = ys

593− Join (x ': xs) ys = x ': Join xs ys

351+type family NullifyFrom (tables :: FromType) :: FromType where

352+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': table5 ::: columns5 ': tables) =

353+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns5 ': table5 ::: NullifyRow columns4 ': NullifyFrom tables

354+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': tables) =

355+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns4 ': NullifyFrom tables

356+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': tables) =

357+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': NullifyFrom tables

358+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': tables) =

359+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': NullifyFrom tables

360+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': tables) =

361+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': NullifyFrom tables

362+ NullifyFrom (table ::: columns ': tables) =

363+ table ::: NullifyRow columns ': NullifyFrom tables

364+ NullifyFrom '[] = '[]

594365

595366-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in

596367-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

@@ -600,30 +371,101 @@ type family Create alias x xs where

600371 Create alias x (alias ::: y ': xs) = TypeError

601372 ('Text "Create: alias "

602373 ':<>: 'ShowType alias

603− ':<>: 'Text "already in use")

374+ ':<>: 'Text "already exists")

604375 Create alias y (x ': xs) = x ': Create alias y xs

605376

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+

606394-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

607395-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

608396-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

609397type family Drop alias xs where

610− 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

611403 Drop alias (x ': xs) = x ': Drop alias xs

612404

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+

613437-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@

614−-- 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`

615439-- and `Squeal.PostgreSQL.Definition.alterColumn`.

616440type family Alter alias x xs where

441+ Alter alias x '[] = TypeError

442+ ('Text "Alter: alias "

443+ ':<>: 'ShowType alias

444+ ':<>: 'Text " does not exist" )

617445 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

618446 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

619447

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+

620453-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@

621454-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

622455-- `Squeal.PostgreSQL.Definition.renameColumn`.

623456type family Rename alias0 alias1 xs where

457+ Rename alias0 alias1 '[] = TypeError

458+ ('Text "Rename: alias "

459+ ':<>: 'ShowType alias0

460+ ':<>: 'Text " does not exist" )

624461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

625462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

626463

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+

627469-- | Check if a `TableConstraint` involves a column

628470type family ConstraintInvolves column constraint where

629471 ConstraintInvolves column ('Check columns) = column `Elem` columns

@@ -640,29 +482,80 @@ type family DropIfConstraintsInvolve column constraints where

640482 (DropIfConstraintsInvolve column constraints)

641483 (alias ::: constraint ': DropIfConstraintsInvolve column constraints)

642484

643−type family Length (xs :: [k]) :: Nat where

644− Length (x : xs) = 1 + Length xs

645− Length '[] = 0

646−

647485-- | A `SchemumType` is a user-defined type, either a `Table`,

648486-- `View` or `Typedef`.

649487data SchemumType

650488 = Table TableType

651− | View RelationType

489+ | View RowType

652490 | Typedef PGType

653−

654−-- | The schema of a database consists of a list of aliased,

655−-- user-defined `SchemumType`s.

491+ | Index IndexType

492+ | Function FunctionType

493+ | Operator OperatorType

494+ | UnsafeSchemum Symbol

495+

496+type FunctionType = ([NullityType], ReturnsType)

497+

498+data IndexType

499+ = Btree

500+ | Hash

501+ | Gist

502+ | Spgist

503+ | Gin

504+ | Brin

505+

506+data ReturnsType

507+ = Returns NullityType

508+ | ReturnsTable RowType

509+

510+data OperatorType

511+ = BinaryOp NullityType NullityType NullityType

512+ | LeftOp NullityType NullityType

513+ | RightOp NullityType NullityType

514+

515+{- | The schema of a database consists of a list of aliased,

516+user-defined `SchemumType`s.

517+

518+>>> :{

519+type family Schema :: SchemaType where

520+ Schema =

521+ '[ "users" ::: 'Table (

522+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

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

524+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

525+ ])

526+ , "emails" ::: 'Table (

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

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

529+ ] :=>

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

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

532+ , "email" ::: 'NoDef :=> 'Null 'PGtext

533+ ])

534+ ]

535+:}

536+-}

656537type SchemaType = [(Symbol,SchemumType)]

657538

658−-- | Used in `Squeal.Postgresql.Manipulation.with`.

659−type family With

660− (relations :: RelationsType)

661− (schema :: SchemaType)

662− :: SchemaType where

663− With '[] schema = schema

664− With (alias ::: rel ': rels) schema =

665− alias ::: 'View rel ': With rels schema

539+{- |

540+A database contains one or more named schemas, which in turn contain tables.

541+The same object name can be used in different schemas without conflict;

542+for example, both schema1 and myschema can contain tables named mytable.

543+Unlike databases, schemas are not rigidly separated:

544+a user can access objects in any of the schemas in the database they are connected to,

545+if they have privileges to do so.

546+

547+There are several reasons why one might want to use schemas:

548+

549+ * To allow many users to use one database without interfering with each other.

550+ * To organize database objects into logical groups to make them more manageable.

551+ * Third-party applications can be put into separate schemas

552+ so they do not collide with the names of other objects.

553+-}

554+type SchemasType = [(Symbol,SchemaType)]

555+

556+-- | A type family to use for a single schema database.

557+type family Public (schema :: SchemaType) :: SchemasType

558+ where Public schema = '["public" ::: schema]

666559

667560-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas

668561-- the overloaded label, `fromLabel` is used for column references,

@@ -675,132 +568,29 @@ instance labels ~ '[label]

675568 => IsPGlabel label (NP PGlabel labels) where label = PGlabel :* Nil

676569-- | A `PGlabel` unit type with an `IsPGlabel` instance

677570data PGlabel (label :: Symbol) = PGlabel

678−-- | Renders a label

679−renderLabel :: KnownSymbol label => proxy label -> ByteString

680−renderLabel (_ :: proxy label) =

681− "\'" <> renderSymbol @label <> "\'"

682−-- | Renders a list of labels

683−renderLabels

684− :: All KnownSymbol labels => NP PGlabel labels -> [ByteString]

685−renderLabels = hcollapse

686− . hcmap (Proxy @KnownSymbol) (K . renderLabel)

687−

688−-- | The `PG` type family embeds a subset of Haskell types

689−-- as Postgres basic types.

690−--

691−-- >>> :kind! PG LocalTime

692−-- PG LocalTime :: PGType

693−-- = 'PGtimestamp

694−type family PG (hask :: Type) :: PGType where

695− PG Bool = 'PGbool

696− PG Int16 = 'PGint2

697− PG Int32 = 'PGint4

698− PG Int64 = 'PGint8

699− PG Word16 = 'PGint2

700− PG Word32 = 'PGint4

701− PG Word64 = 'PGint8

702− PG Scientific = 'PGnumeric

703− PG Float = 'PGfloat4

704− PG Double = 'PGfloat8

705− PG Char = 'PGchar 1

706− PG Text = 'PGtext

707− PG Lazy.Text = 'PGtext

708− PG ByteString = 'PGbytea

709− PG Lazy.ByteString = 'PGbytea

710− PG LocalTime = 'PGtimestamp

711− PG UTCTime = 'PGtimestamptz

712− PG Day = 'PGdate

713− PG TimeOfDay = 'PGtime

714− PG (TimeOfDay, TimeZone) = 'PGtimetz

715− PG DiffTime = 'PGinterval

716− PG UUID = 'PGuuid

717− PG (NetAddr IP) = 'PGinet

718− PG Value = 'PGjson

719− PG ty = TypeError

720− ('Text "There is no Postgres basic type for " ':<>: 'ShowType ty)

721−

722−-- | The `EnumFrom` type family embeds Haskell enum types, ADTs with

723−-- nullary constructors, as Postgres enum types

724−--

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

726−-- >>> instance Generic Schwarma

727−-- >>> instance HasDatatypeInfo Schwarma

728−-- >>> :kind! EnumFrom Schwarma

729−-- EnumFrom Schwarma :: PGType

730−-- = 'PGenum '["Beef", "Lamb", "Chicken"]

731−type family EnumFrom (hask :: Type) :: PGType where

732− EnumFrom hask = 'PGenum (LabelsFrom hask)

733−

734−-- | The `LabelsFrom` type family calculates the constructors of a

735−-- Haskell enum type.

736−--

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

738−-- >>> instance Generic Schwarma

739−-- >>> instance HasDatatypeInfo Schwarma

740−-- >>> :kind! LabelsFrom Schwarma

741−-- LabelsFrom Schwarma :: [Type.ConstructorName]

742−-- = '["Beef", "Lamb", "Chicken"]

743−type family LabelsFrom (hask :: Type) :: [Type.ConstructorName] where

744− LabelsFrom hask =

745− ConstructorNamesOf (ConstructorsOf (DatatypeInfoOf hask))

746−

747−-- | The `CompositeFrom` type family embeds Haskell record types as

748−-- Postgres composite types, as long as the record fields

749−-- are `Maybe`s of Haskell types that can be embedded as basic types

750−-- with the `PG` type family.

751−--

752−-- >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic

753−-- >>> instance Generic Row

754−-- >>> instance HasDatatypeInfo Row

755−-- >>> :kind! CompositeFrom Row

756−-- CompositeFrom Row :: PGType

757−-- = 'PGcomposite '["a" ::: 'Null 'PGint2, "b" ::: 'Null 'PGtimestamp]

758−type family CompositeFrom (hask :: Type) :: PGType where

759− CompositeFrom hask = 'PGcomposite (PGFieldsFrom hask)

760−

761−type family PGFieldsFrom (hask :: Type) :: RelationType where

762− PGFieldsFrom hask = PGFieldsOf (RecordCodeOf hask)

763−

764−type family PGFieldsOf (fields :: [(Symbol, Type)]) :: RelationType where

765− PGFieldsOf '[] = '[]

766− PGFieldsOf (field ': fields) = PGFieldOf field ': PGFieldsOf fields

767−

768−type family PGFieldOf (field :: (Symbol, Type)) :: (Symbol, NullityType) where

769− PGFieldOf (field ::: hask) = field ::: NullityTypeOf hask

770−

771−type family NullityTypeOf (hask :: Type) :: NullityType where

772− NullityTypeOf (Maybe hask) = 'Null (PG hask)

773− NullityTypeOf hask = 'NotNull (PG hask)

774−

775−-- | Calculates constructors of a datatype.

776−type family ConstructorsOf (datatype :: Type.DatatypeInfo)

777− :: [Type.ConstructorInfo] where

778− ConstructorsOf ('Type.ADT _module _datatype constructors) =

779− constructors

780− ConstructorsOf ('Type.Newtype _module _datatype constructor) =

781− '[constructor]

782−

783−-- | Calculates the name of a nullary constructor, otherwise

784−-- generates a type error.

785−type family ConstructorNameOf (constructors :: Type.ConstructorInfo)

786− :: Type.ConstructorName where

787− ConstructorNameOf ('Type.Constructor name) = name

788− ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

789− ('Text "ConstructorNameOf error: non-nullary constructor "

790− ':<>: 'Text name)

791− ConstructorNameOf ('Type.Record name _fields) = TypeError

792− ('Text "ConstructorNameOf error: non-nullary constructor "

793− ':<>: 'Text name)

794−

795−-- | Calculate the names of nullary constructors.

796−type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

797− :: [Type.ConstructorName] where

798− ConstructorNamesOf '[] = '[]

799− ConstructorNamesOf (constructor ': constructors) =

800− 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)

801578

802579-- | Is a type a valid JSON key?

803−type PGjsonKey key = key `In` '[ 'PGint2, 'PGint4, 'PGtext ]

580+type PGJsonKey = '[ 'PGint2, 'PGint4, 'PGtext ]

804581

805582-- | Is a type a valid JSON type?

806−type PGjson_ json = json `In` '[ 'PGjson, 'PGjsonb ]

583+type PGJsonType = '[ 'PGjson, 'PGjsonb ]

584+

585+-- | Utility class for `AllUnique` to provide nicer error messages.

586+class IsNotElem x isElem where

587+instance IsNotElem x 'False where

588+instance (TypeError ( 'Text "Cannot assign to "

589+ ':<>: 'ShowType alias

590+ ':<>: 'Text " more than once"))

591+ => IsNotElem '(alias, a) 'True where

592+

593+-- | No elem of @xs@ appears more than once, in the context of assignment.

594+class AllUnique (xs :: [(Symbol, a)]) where

595+instance AllUnique '[] where

596+instance (IsNotElem x (Elem x xs), AllUnique xs) => AllUnique (x ': xs) where

squeal-postgresql/src/Squeal/PostgreSQL/Transaction.hs+101−74

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

11{-|

22Module: Squeal.PostgreSQL.Transaction

33Description: Squeal transaction control language

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

55Maintainer: eitan@morphism.tech

66Stability: experimental

@@ -9,98 +9,125 @@ Squeal transaction control language.

99-}

1010

1111{-# LANGUAGE

12− FlexibleContexts

12+ DataKinds

13+ , FlexibleContexts

1314 , LambdaCase

1415 , OverloadedStrings

16+ , TypeInType

1517#-}

1618

1719module Squeal.PostgreSQL.Transaction

1820 ( -- * Transaction

1921 transactionally

2022 , transactionally_

23+ , transactionallyRetry

24+ , ephemerally

25+ , ephemerally_

2126 , begin

2227 , commit

2328 , rollback

24− , transactionallySchema

25− , transactionallySchema_

2629 -- * Transaction Mode

2730 , TransactionMode (..)

2831 , defaultMode

2932 , longRunningMode

3033 , IsolationLevel (..)

31− , renderIsolationLevel

3234 , AccessMode (..)

33− , renderAccessMode

3435 , DeferrableMode (..)

35− , renderDeferrableMode

3636 ) where

3737

38−import Control.Exception.Lifted

39−import Control.Monad.Base

40−import Control.Monad.Trans.Control

41−import Data.ByteString

42−import Data.Monoid

43−import Generics.SOP

44−

45−import qualified Database.PostgreSQL.LibPQ as LibPQ

38+import UnliftIO

4639

4740import Squeal.PostgreSQL.Manipulation

4841import Squeal.PostgreSQL.Render

4942import Squeal.PostgreSQL.PQ

50−import Squeal.PostgreSQL.Schema

5143

52−-- | Run a schema invariant computation `transactionally`.

44+{- | Run a computation `transactionally`;

45+first `begin`,

46+then run the computation,

47+`onException` `rollback` and rethrow the exception,

48+otherwise `commit` and `return` the result.

49+-}

5350transactionally

54− :: (MonadBaseControl IO tx, MonadPQ schema tx)

51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

5552 => TransactionMode

5653 -> tx x -- ^ run inside a transaction

5754 -> tx x

5855transactionally mode tx = mask $ \restore -> do

59− _ <- begin mode

60− result <- restore tx `onException` rollback

61− _ <- commit

56+ manipulate_ $ begin mode

57+ result <- restore tx `onException` (manipulate_ rollback)

58+ manipulate_ commit

6259 return result

6360

64−-- | Run a schema invariant computation `transactionally_` in `defaultMode`.

61+-- | Run a computation `transactionally_`, in `defaultMode`.

6562transactionally_

66− :: (MonadBaseControl IO tx, MonadPQ schema tx)

63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

6764 => tx x -- ^ run inside a transaction

6865 -> tx x

6966transactionally_ = transactionally defaultMode

7067

71−-- | @BEGIN@ a transaction.

72−begin :: MonadPQ schema tx => TransactionMode -> tx (K Result NilRelation)

73−begin mode = manipulate . UnsafeManipulation $

74− "BEGIN" <+> renderTransactionMode mode <> ";"

68+{- |

69+`transactionallyRetry` a computation;

70+

71+* first `begin`,

72+* then `try` the computation,

73+ - if it raises a serialization failure then `rollback` and restart the transaction,

74+ - if it raises any other exception then `rollback` and rethrow the exception,

75+ - otherwise `commit` and `return` the result.

76+-}

77+transactionallyRetry

78+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

79+ => TransactionMode

80+ -> tx x -- ^ run inside a transaction

81+ -> tx x

82+transactionallyRetry mode tx = mask $ \restore ->

83+ loop . try $ do

84+ x <- restore tx

85+ manipulate_ commit

86+ return x

87+ where

88+ loop attempt = do

89+ manipulate_ $ begin mode

90+ attempt >>= \case

91+ Left (PQException (PQState _ (Just "40001") _)) -> do

92+ manipulate_ rollback

93+ loop attempt

94+ Left err -> do

95+ manipulate_ rollback

96+ throwIO err

97+ Right x -> return x

98+

99+{- | Run a computation `ephemerally`;

100+Like `transactionally` but always `rollback`, useful in testing.

101+-}

102+ephemerally

103+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

104+ => TransactionMode

105+ -> tx x -- ^ run inside an ephemeral transaction

106+ -> tx x

107+ephemerally mode tx = mask $ \restore -> do

108+ manipulate_ $ begin mode

109+ result <- restore tx `onException` (manipulate_ rollback)

110+ manipulate_ rollback

111+ return result

75112

76−-- | @COMMIT@ a schema invariant transaction.

77−commit :: MonadPQ schema tx => tx (K Result NilRelation)

78−commit = manipulate $ UnsafeManipulation "COMMIT;"

113+{- | Run a computation `ephemerally` in `defaultMode`. -}

114+ephemerally_

115+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

116+ => tx x -- ^ run inside an ephemeral transaction

117+ -> tx x

118+ephemerally_ = ephemerally defaultMode

119+

120+-- | @BEGIN@ a transaction.

121+begin :: TransactionMode -> Manipulation_ schemas () ()

122+begin mode = UnsafeManipulation $ "BEGIN" <+> renderSQL mode

79123

80−-- | @ROLLBACK@ a schema invariant transaction.

81−rollback :: MonadPQ schema tx => tx (K Result NilRelation)

82−rollback = manipulate $ UnsafeManipulation "ROLLBACK;"

124+-- | @COMMIT@ a transaction.

125+commit :: Manipulation_ schemas () ()

126+commit = UnsafeManipulation "COMMIT"

83127

84−-- | Run a schema changing computation `transactionallySchema`.

85−transactionallySchema

86− :: MonadBaseControl IO io

87− => TransactionMode

88− -> PQ schema0 schema1 io x

89− -> PQ schema0 schema1 io x

90−transactionallySchema mode u = PQ $ \ conn -> mask $ \ restore -> do

91− _ <- liftBase . LibPQ.exec (unK conn) $

92− "BEGIN" <+> renderTransactionMode mode <> ";"

93− x <- restore (unPQ u conn)

94− `onException` (liftBase (LibPQ.exec (unK conn) "ROLLBACK"))

95− _ <- liftBase $ LibPQ.exec (unK conn) "COMMIT"

96− return x

97−

98−-- | Run a schema changing computation `transactionallySchema_` in `DefaultMode`.

99−transactionallySchema_

100− :: MonadBaseControl IO io

101− => PQ schema0 schema1 io x

102− -> PQ schema0 schema1 io x

103−transactionallySchema_ = transactionallySchema defaultMode

128+-- | @ROLLBACK@ a transaction.

129+rollback :: Manipulation_ schemas () ()

130+rollback = UnsafeManipulation "ROLLBACK"

104131

105132-- | The available transaction characteristics are the transaction `IsolationLevel`,

106133-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

@@ -113,7 +140,7 @@ data TransactionMode = TransactionMode

113140-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

114141-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

115142defaultMode :: TransactionMode

116−defaultMode = TransactionMode Serializable ReadWrite NotDeferrable

143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable

117144

118145-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

119146-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

@@ -122,12 +149,12 @@ longRunningMode :: TransactionMode

122149longRunningMode = TransactionMode Serializable ReadOnly Deferrable

123150

124151-- | Render a `TransactionMode`.

125−renderTransactionMode :: TransactionMode -> ByteString

126−renderTransactionMode mode =

127− "ISOLATION LEVEL"

128− <+> renderIsolationLevel (isolationLevel mode)

129− <+> renderAccessMode (accessMode mode)

130− <+> renderDeferrableMode (deferrableMode mode)

152+instance RenderSQL TransactionMode where

153+ renderSQL mode =

154+ "ISOLATION LEVEL"

155+ <+> renderSQL (isolationLevel mode)

156+ <+> renderSQL (accessMode mode)

157+ <+> renderSQL (deferrableMode mode)

131158

132159-- | The SQL standard defines four levels of transaction isolation.

133160-- The most strict is `Serializable`, which is defined by the standard in a paragraph

@@ -178,12 +205,12 @@ data IsolationLevel

178205 deriving (Show, Eq)

179206

180207-- | Render an `IsolationLevel`.

181−renderIsolationLevel :: IsolationLevel -> ByteString

182−renderIsolationLevel = \case

183− Serializable -> "SERIALIZABLE"

184− ReadCommitted -> "READ COMMITTED"

185− ReadUncommitted -> "READ UNCOMMITTED"

186− RepeatableRead -> "REPEATABLE READ"

208+instance RenderSQL IsolationLevel where

209+ renderSQL = \case

210+ Serializable -> "SERIALIZABLE"

211+ ReadCommitted -> "READ COMMITTED"

212+ ReadUncommitted -> "READ UNCOMMITTED"

213+ RepeatableRead -> "REPEATABLE READ"

187214

188215-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

189216-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

@@ -200,10 +227,10 @@ data AccessMode

200227 deriving (Show, Eq)

201228

202229-- | Render an `AccessMode`.

203−renderAccessMode :: AccessMode -> ByteString

204−renderAccessMode = \case

205− ReadWrite -> "READ WRITE"

206− ReadOnly -> "READ ONLY"

230+instance RenderSQL AccessMode where

231+ renderSQL = \case

232+ ReadWrite -> "READ WRITE"

233+ ReadOnly -> "READ ONLY"

207234

208235-- | The `Deferrable` transaction property has no effect

209236-- unless the transaction is also `Serializable` and `ReadOnly`.

@@ -219,7 +246,7 @@ data DeferrableMode

219246 deriving (Show, Eq)

220247

221248-- | Render a `DeferrableMode`.

222−renderDeferrableMode :: DeferrableMode -> ByteString

223−renderDeferrableMode = \case

224− Deferrable -> "DEFERRABLE"

225− NotDeferrable -> "NOT DEFERRABLE"

249+instance RenderSQL DeferrableMode where

250+ renderSQL = \case

251+ Deferrable -> "DEFERRABLE"

252+ NotDeferrable -> "NOT DEFERRABLE"

squeal-postgresql/test/Doc.hsnew file+6

@@ -0,0 +1,6 @@

1+module Main (main) where

3+import Test.DocTest

5+main :: IO ()

6+main = doctest [ "-isrc", "src" ]

squeal-postgresql/test/DocTest.hsdeleted−18

@@ -1,18 +0,0 @@

1−module Main (main) where

2−

3−import Test.DocTest

4−

5−main :: IO ()

6−main = doctest

7− [ "-isrc"

8− , "src/Squeal/PostgreSQL.hs"

9− , "src/Squeal/PostgreSQL/Binary.hs"

10− , "src/Squeal/PostgreSQL/Definition.hs"

11− , "src/Squeal/PostgreSQL/Manipulation.hs"

12− , "src/Squeal/PostgreSQL/Query.hs"

13− , "src/Squeal/PostgreSQL/Expression.hs"

14− , "src/Squeal/PostgreSQL/PQ.hs"

15− , "src/Squeal/PostgreSQL/Migration.hs"

16− , "src/Squeal/PostgreSQL/Transaction.hs"

17− , "src/Squeal/PostgreSQL/Pool.hs"

18− ]

squeal-postgresql/test/Property.hsnew file+166

@@ -0,0 +1,166 @@

1+{-# LANGUAGE

2+ DataKinds

3+ , GADTs

4+ , LambdaCase

5+ , OverloadedLabels

6+ , OverloadedStrings

7+ , TypeApplications

8+ , TypeOperators

9+#-}

10+

11+module Main (main) where

12+

13+import Control.Monad.Trans

14+import Data.ByteString (ByteString)

15+import Data.ByteString.Char8 (unpack)

16+import Data.Scientific (fromFloatDigits)

17+import Data.Fixed (Fixed(MkFixed), Micro, Pico)

18+import Data.String (IsString(fromString))

19+import Data.Time

20+import Squeal.PostgreSQL hiding (check, defaultMain, Group)

21+import Hedgehog hiding (Range)

22+import qualified Hedgehog.Gen as Gen

23+import qualified Hedgehog.Main as Main

24+import qualified Hedgehog.Range as Range

25+

26+main :: IO ()

27+main = Main.defaultMain [checkSequential roundtrips]

28+

29+roundtrips :: Group

30+roundtrips = Group "roundtrips"

31+ [ roundtrip int2 genInt16

32+ , roundtrip int4 genInt32

33+ , roundtrip int8 genInt64

34+ , roundtrip bool Gen.bool

35+ , roundtrip numeric genScientific

36+ , roundtrip float4 genFloat

37+ , roundtrip float8 genDouble

38+ , roundtripOn normalizeTimeOfDay time genTimeOfDay

39+ -- , roundtrip timetz genTimeWithZone normalizeTimeWithZone

40+ , roundtripOn normalizeLocalTime timestamp genLocalTime

41+ , roundtrip timestamptz genUTCTime

42+ , roundtrip date genDay

43+ , roundtrip interval genDiffTime

44+ , roundtripOn normalizeIntRange int4range (genRange genInt32)

45+ , roundtripOn normalizeIntRange int8range (genRange genInt64)

46+ , roundtrip numrange (genRange genScientific)

47+ , roundtripOn (fmap normalizeLocalTime) tsrange (genRange genLocalTime)

48+ , roundtrip tstzrange (genRange genUTCTime)

49+ , roundtripOn normalizeIntRange daterange (genRange genDay)

50+ ]

51+ where

52+ genInt16 = Gen.int16 Range.exponentialBounded

53+ genInt32 = Gen.int32 Range.exponentialBounded

54+ genInt64 = Gen.int64 Range.exponentialBounded

55+ genScientific = fromFloatDigits <$> genFloat

56+ genPosFloat = Gen.float

57+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)

58+ genFloat = Gen.prune $ Gen.choice

59+ [ genPosFloat

60+ , negate <$> genPosFloat

61+ , Gen.element [0,1/0] ]

62+ genPosDouble = Gen.double

63+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)

64+ genDouble = Gen.prune $ Gen.choice

65+ [ genPosDouble

66+ , negate <$> genPosDouble

67+ , Gen.element [0,1/0] ]

68+ genRange gen = do

69+ lb <- gen

70+ ub <- Gen.filter (lb <) gen

71+ Gen.element

72+ [ Empty, singleton lb, whole

73+ , lb <=..<= ub , lb <=..< ub, lb <..<= ub, lb <..< ub

74+ , atLeast lb, moreThan lb, atMost ub, lessThan ub ]

75+ genDay = do

76+ y <- toInteger <$> Gen.int (Range.constant 2000 2019)

77+ m <- Gen.int (Range.constant 1 12)

78+ d <- Gen.int (Range.constant 1 28)

79+ return $ fromGregorian y m d

80+ genDiffTime = secondsToDiffTime . toInteger <$>

81+ Gen.int (Range.constant 0 86401)

82+ genUTCTime = UTCTime <$> genDay <*> genDiffTime

83+ genTimeOfDay = do

84+ h <- Gen.int (Range.constant 0 23)

85+ m <- Gen.int (Range.constant 0 59)

86+ s <- MkFixed . toInteger <$> Gen.int (Range.constant 0 59)

87+ return $ TimeOfDay h m s

88+ genLocalTime = LocalTime <$> genDay <*> genTimeOfDay

89+ -- genTimeZone = Gen.element $ map (read @TimeZone)

90+ -- [ "UTC", "UT", "GMT", "EST", "EDT", "CST"

91+ -- , "CDT", "MST", "MDT", "PST", "PDT" ]

92+ -- genTimeWithZone = (,) <$> genTimeOfDay <*> genTimeZone

93+

94+roundtrip

95+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)

96+ => TypeExpression schemas ('NotNull ty)

97+ -> Gen x

98+ -> (PropertyName, Property)

99+roundtrip = roundtripOn id

100+

101+roundtripOn

102+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)

103+ => (x -> x)

104+ -> TypeExpression schemas ('NotNull ty)

105+ -> Gen x

106+ -> (PropertyName, Property)

107+roundtripOn norm ty gen = propertyWithName $ do

108+ x <- forAll gen

109+ Just (Only y) <- lift . withConnection connectionString $

110+ firstRow =<< runQueryParams

111+ (values_ (parameter @1 ty `as` #fromOnly)) (Only x)

112+ norm x === y

113+ where

114+ propertyWithName prop =

115+ (fromString (unpack (renderSQL ty)), property prop)

116+

117+maxPosFloat :: RealFloat a => a

118+maxPosFloat = x

119+ where

120+ n = floatDigits x

121+ b = floatRadix x

122+ (_, u) = floatRange x

123+ x = encodeFloat (b^n - 1) (u - n)

124+

125+minPosFloat :: RealFloat a => a

126+minPosFloat = x

127+ where

128+ n = floatDigits x

129+ b = floatRadix x

130+ (l, _) = floatRange x

131+ x = encodeFloat (b^n - 1) (l - n - 1)

132+

133+connectionString :: ByteString

134+connectionString = "host=localhost port=5432 dbname=exampledb"

135+

136+normalizeIntRange :: (Enum int, Ord int) => Range int -> Range int

137+normalizeIntRange = \case

138+ Empty -> Empty

139+ NonEmpty l u ->

140+ let

141+ l' = normalizeL l

142+ u' = normalizeU u

143+ in if emptyNormalized l' u' then Empty else NonEmpty l' u'

144+ where

145+ normalizeL = \case

146+ Open l -> Closed (succ l)

147+ normalized -> normalized

148+ normalizeU = \case

149+ Closed u -> Open (succ u)

150+ normalized -> normalized

151+ emptyNormalized (Closed l) (Open u) = l >= u

152+ emptyNormalized _ _ = False

153+

154+normalizeTimeOfDay :: TimeOfDay -> TimeOfDay

155+normalizeTimeOfDay (TimeOfDay h m s) = TimeOfDay h m

156+ . fromRational @Pico

157+ . toRational @Micro

158+ . fromRational @Micro

159+ . toRational @Pico

160+ $ s

161+

162+normalizeLocalTime :: LocalTime -> LocalTime

163+normalizeLocalTime (LocalTime d t) = LocalTime d (normalizeTimeOfDay t)

164+

165+-- normalizeTimeWithZone :: (TimeOfDay, TimeZone) -> (TimeOfDay, TimeZone)

166+-- normalizeTimeWithZone (t, z) = (normalizeTimeOfDay t, z)

squeal-postgresql/test/Spec.hsnew file+136

@@ -0,0 +1,136 @@

1+{-# LANGUAGE

2+ DataKinds

3+ , DeriveAnyClass

4+ , DeriveGeneric

5+ , DerivingStrategies

6+ , DuplicateRecordFields

7+ , FlexibleContexts

8+ , OverloadedLabels

9+ , OverloadedLists

10+ , OverloadedStrings

11+ , TypeApplications

12+ , TypeFamilies

13+ , TypeInType

14+ , TypeOperators

15+#-}

16+

17+module Main (main) where

18+

19+import Control.Concurrent.Async (replicateConcurrently)

20+import Data.ByteString (ByteString)

21+import Data.Int (Int32)

22+import Data.Text (Text)

23+import Test.Hspec

24+

25+import qualified Generics.SOP as SOP

26+import qualified GHC.Generics as GHC

27+

28+import Squeal.PostgreSQL

29+

30+main :: IO ()

31+main = hspec spec

32+

33+type Schemas = Public

34+ '[ "users" ::: 'Table (

35+ '[ "pk_users" ::: 'PrimaryKey '["id"]

36+ , "unique_names" ::: 'Unique '["name"]

37+ ] :=>

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

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

40+

41+data User = User

42+ { userName :: Text

43+ } deriving stock (Eq, Show, GHC.Generic)

44+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

45+

46+insertUser :: Manipulation_ Schemas User ()

47+insertUser = insertInto_ #users

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

49+

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

51+setup =

52+ createTable #users

53+ ( serial `as` #id :*

54+ notNullable text `as` #name )

55+ ( primaryKey #id `as` #pk_users :*

56+ unique #name `as` #unique_names )

57+

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

59+teardown = dropTable #users

60+

61+silence :: MonadPQ schemas pq => pq ()

62+silence = manipulate_ $

63+ UnsafeManipulation "SET client_min_messages TO WARNING;"

64+

65+setupDB :: IO ()

66+setupDB = withConnection connectionString $

67+ silence & pqThen (define setup)

68+

69+dropDB :: IO ()

70+dropDB = withConnection connectionString $

71+ silence & pqThen (define teardown)

72+

73+connectionString :: ByteString

74+connectionString = "host=localhost port=5432 dbname=exampledb"

75+

76+spec :: Spec

77+spec = before_ setupDB . after_ dropDB $ do

78+

79+ describe "Exceptions" $ do

80+

81+ let

82+ testUser = User "TestUser"

83+ newUser = manipulateParams_ insertUser

84+ insertUserTwice = newUser testUser >> newUser testUser

85+ err23505 = PQException $ PQState FatalError (Just "23505")

86+ (Just "ERROR: duplicate key value violates unique constraint \"unique_names\"\nDETAIL: Key (name)=(TestUser) already exists.\n")

87+

88+ it "should be thrown for constraint violation" $

89+ withConnection connectionString insertUserTwice

90+ `shouldThrow` (== err23505)

91+

92+ it "should be rethrown for constraint violation in a transaction" $

93+ withConnection connectionString (transactionally_ insertUserTwice)

94+ `shouldThrow` (== err23505)

95+

96+ describe "Pools" $

97+

98+ it "should manage concurrent transactions" $ do

99+ pool <- createConnectionPool

100+ "host=localhost port=5432 dbname=exampledb" 1 0.5 10

101+ let

102+ query :: Query_ (Public '[]) () (Only Char)

103+ query = values_ (literal 'a' `as` #fromOnly)

104+ session = usingConnectionPool pool . transactionally_ $ do

105+ result <- runQuery query

106+ Just (Only chr) <- firstRow result

107+ return chr

108+ chrs <- replicateConcurrently 10 session

109+ chrs `shouldSatisfy` all (== 'a')

110+

111+ describe "Ranges" $

112+

113+ it "should correctly decode ranges" $ do

114+

115+ rangesOut <- withConnection connectionString $ do

116+ let

117+ query :: Query_ (Public '[]) () (Only (Range Int32))

118+ query = values

119+ ( range int4range (atLeast 3) `as` #fromOnly )

120+ [ range int4range (3 <=..< 5) `as` #fromOnly

121+ , range int4range Empty `as` #fromOnly

122+ , range int4range whole `as` #fromOnly ]

123+ getRows =<< runQuery query

124+ (fromOnly <$> rangesOut :: [Range Int32]) `shouldBe`

125+ [ atLeast 3, 3 <=..< 5, Empty, whole ]

126+

127+ describe "Parameters" $ do

128+

129+ it "should run queries that don't reference all their parameters" $ do

130+

131+ out <- withConnection connectionString $ do

132+ let

133+ query :: Query_ (Public '[]) (Char,Int32) (Only Int32)

134+ query = values_ (param @2 `as` #fromOnly)

135+ firstRow =<< runQueryParams query ('a', 3 :: Int32)

136+ (fromOnly <$> out :: Maybe Int32) `shouldBe` Just 3

squeal-postgresql/test/Specs/ExceptionHandling.hsdeleted−118

@@ -1,118 +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− (

13− specs

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− manipulate (UnsafeManipulation "SET client_min_messages = warning;")

90− & pqThen $ migrateUp $ single migration

91−

92−dropDB :: IO ()

93−dropDB = void . withConnection connectionString $

94− manipulate (UnsafeManipulation "SET client_min_messages = warning;")

95− & pqThen $ migrateDown $ single migration

96−

97−connectionString :: Char8.ByteString

98−connectionString = "host=localhost port=5432 dbname=exampledb"

99−

100−testUser :: User

101−testUser = User "TestUser" Nothing []

102−

103−newUser :: (MonadBase IO m, MonadPQ Schema m) => User -> m ()

104−newUser u = void $ manipulateParams insertUser (userName u, userVec u)

105−

106−insertUserTwice :: (MonadBase IO m, MonadPQ Schema m) => m ()

107−insertUserTwice = newUser testUser >> newUser testUser

108−

109−specs :: SpecWith ()

110−specs = before_ setupDB $ after_ dropDB $

111− describe "Exceptions" $ do

112− it "Should be raised in transactions and cause rollback" $

113− withConnection connectionString insertUserTwice

114− `shouldThrow` (const True :: Selector SquealException)

115−

116− it "Should be raised outside of transactions" $

117− withConnection connectionString (transactionally_ insertUserTwice)

118− `shouldThrow` (const True :: Selector SquealException)

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+5−2

@@ -1,5 +1,8 @@

1−resolver: lts-11.15

1+resolver: nightly-2019-07-14

22packages:

33- squeal-postgresql

45extra-deps:

5−- records-sop-0.1.0.0

6+- unliftio-pool-0.2.1.0

7+- github: morphismtech/free-categories

8+ commit: c0e555fbefb5c21619e532264c4dfeac556d0630