b3f6651..dev · squeal · git.iko.soy

git.iko.soy/squeal

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.circleci/config.yml+3−2

since splitsnapshots

unifiedsplit

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

2jobs:

3 build:

4 docker:

5− - image: haskell:8.2.2

5+ - image: haskell:8.6.5

6 - image: circleci/postgres:latest

7 environment:

8+ POSTGRES_USER: root

8 POSTGRES_DB: exampledb

9 POSTGRES_DB: exampledb

9 steps:

10 steps:

10 - checkout

11 - checkout

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

13 - dependency-cache

14 - dependency-cache

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

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

15 - run: stack upgrade && stack update

16 - run: stack upgrade && stack update

16− - run: stack build

17+ - run: stack build --fast

17 - run: stack test

18 - run: stack test

18 - run: stack haddock

19 - run: stack haddock

19 - save_cache:

20 - save_cache:

README.md+83−87

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

45* connection pools

46* transactions

47* views

48−* composite and enumerated types

48+* array, composite and enumerated types

49+* json functions and operations

50+* multischema support

51+* correlated subqueries

52+* window functions

53+* text search

50## installation

55## installation

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

54## testing

59## testing

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`.

58`stack test`

63`stack test`

65+## contributing

66+

67+We welcome contributors.

68+Please make pull requests on the `dev` branch instead of `master`.

69+The `Issues` page is a good place to communicate.

70+

60## usage

71## usage

62Let's see an example!

73Let's see an example!

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

65features.

76features.

67```Haskell

78```Haskell

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

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

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

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

70```

81```

72We'll need some imports.

83We'll need some imports.

74```Haskell

85```Haskell

75−>>> import Control.Monad (void)

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

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

77>>> import Data.Int (Int32)

87>>> import Data.Int (Int32)

78>>> import Data.Text (Text)

88>>> import Data.Text (Text)

79>>> import Squeal.PostgreSQL

89>>> import Squeal.PostgreSQL

80−>>> import Squeal.PostgreSQL.Render

81```

90```

83We'll use generics to easily convert between Haskell and PostgreSQL values.

92We'll use generics to easily convert between Haskell and PostgreSQL values.

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

101

93```Haskell

102```Haskell

94>>> :{

103>>> :{

104+type UsersColumns =

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

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

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

108+type EmailsColumns =

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

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

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

112+type EmailsConstraints =

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

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

95type Schema =

115type Schema =

96− '[ "users" ::: 'Table (

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

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

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

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

100− ])

101− , "emails" ::: 'Table (

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

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

118+type Schemas = Public Schema

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

104− ] :=>

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

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

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

108− ])

109− ]

110:}

119:}

111```

120```

112

121

113Notice the use of type operators.

122Notice the use of type operators.

114

123

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

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

116a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's `::`

125a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's `::`

117operator.

126operator.

118

127

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

121yielding a `ColumnType`. It is intended to connote Haskell's `=>` operator

130yielding a `ColumnType`. It is intended to connote Haskell's `=>` operator

122

131

123Next, we'll write `Definition`s to set up and tear down the schema. In

132Next, we'll write `Definition`s to set up and tear down the schema. In

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

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

125has two type parameters, corresponding to the schema

134has two type parameters, corresponding to the schema

126before being run and the schema after. We can compose definitions using `>>>`.

135before being run and the schema after. We can compose definitions using `>>>`.

127Here and in the rest of our commands we make use of overloaded

136Here and in the rest of our commands we make use of overloaded

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

130```Haskell

139```Haskell

131>>> :{

140>>> :{

132let

141let

133− setup :: Definition '[] Schema

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

134− setup =

143+ setup =

135 createTable #users

144 createTable #users

136− ( serial `As` #id :*

145+ ( serial `as` #id :*

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

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

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

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

139 createTable #emails

148 createTable #emails

140− ( serial `As` #id :*

149+ ( serial `as` #id :*

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

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

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

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

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

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

144 foreignKey #user_id #users #id

153 foreignKey #user_id #users #id

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

154+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

146:}

155:}

147```

156```

148

157

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

162```Haskell

171```Haskell

163>>> :{

172>>> :{

164let

173let

165− teardown :: Definition Schema '[]

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

166 teardown = dropTable #emails >>> dropTable #users

175 teardown = dropTable #emails >>> dropTable #users

167:}

176:}

168

177

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

171DROP TABLE "users";

180DROP TABLE "users";

172```

181```

173

182

183+We'll need a Haskell type for `User`s. We give the type `SOP.Generic` and

184+`SOP.HasDatatypeInfo` instances so that we can encode and decode `User`s.

185+

186+```Haskell

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

188+>>> instance SOP.Generic User

189+>>> instance SOP.HasDatatypeInfo User

190+```

191+

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

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

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

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

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

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

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

195+and an output row. When

178we insert into the users table, we will need a parameter for the `name`

196we insert into the users table, we will need a parameter for the `name`

179field but not for the `id` field. Since it's serial, we can use a default

197field but not for the `id` field. Since it's serial, we can use a default

180value. However, since the emails table refers to the users table, we will

198value. However, since the emails table refers to the users table, we will

181need to retrieve the user id that the insert generates and insert it into

199need to retrieve the user id that the insert generates and insert it into

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

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

183−of our inserts.

201+`with` statement.

184

202

185```Haskell

203```Haskell

186>>> :{

204>>> :{

187let

205let

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

206+ insertUser :: Manipulation_ Schemas User ()

189− insertUser = insertRow #users

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

208+ where

209+ u = insertInto #users

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

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

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

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

192−:}

212+ e = insertInto_ #emails $ Select

193−

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

194−>>> :{

214+ (from (common #u))

195−let

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

197− insertEmail = insertRow #emails

198− ( Default `As` #id :*

199− Set (param @1) `As` #user_id :*

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

201− OnConflictDoNothing (Returning Nil)

202:}

215:}

203

216

204>>> printSQL insertUser

217>>> printSQL insertUser

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

218+WITH "u" AS (INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) RETURNING "id" AS "id", ($2 :: text) AS "email") INSERT INTO "emails" ("user_id", "email") SELECT "u"."id", "u"."email" FROM "u" AS "u"

206−>>> printSQL insertEmail

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

208```

219```

209

220

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

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

211interested in the ids here, just the usernames and email addresses. We

222interested in the ids here, just the usernames and email addresses. We

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

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

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

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

214

225

215```Haskell

226```Haskell

216>>> :{

227>>> :{

217let

228let

218− getUsers :: Query Schema '[]

229+ getUsers :: Query_ Schemas () User

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

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

221− getUsers = select

230+ getUsers = select_

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

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

223− ( from (table (#users `As` #u)

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

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

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

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

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

226:}

235:}

227

236

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

229SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

238SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

230```

239```

231

240

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

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

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

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

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

237−

238−```Haskell

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

240−>>> instance SOP.Generic User

241−>>> instance SOP.HasDatatypeInfo User

242−```

243−

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

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

245

242

246```Haskell

243```Haskell

247>>> :{

244>>> :{

248let

245let

249 users :: [User]

246 users :: [User]

250− users =

247+ users =

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

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

252 , User "Bob" Nothing

249 , User "Bob" Nothing

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

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

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

266```Haskell

263```Haskell

267>>> :{

264>>> :{

268let

265let

269− session :: PQ Schema Schema IO ()

266+ session :: PQ Schemas Schemas IO ()

270 session = do

267 session = do

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

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

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

268+ _ <- traversePrepared_ insertUser users

274 usersResult <- runQuery getUsers

269 usersResult <- runQuery getUsers

275 usersRows <- getRows usersResult

270 usersRows <- getRows usersResult

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

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

277in

272in

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

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

279 define setup

274 define setup

280 & pqThen session

275 & pqThen session

281 & pqThen (define teardown)

276 & pqThen (define teardown)

282:}

277:}

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

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

279+-}

284```

280```

RELEASE NOTES.md+838−1

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

1## RELEASE NOTES

3+### Version 0.5

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

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

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

9+**Multi-schema support**

10+

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

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

13+

14+```Haskell

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

16+```

17+

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

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

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

21+

22+```Haskell

23+-- Squeal 0.4

24+setup :: Definition '[] Schema

25+

26+-- Squeal 0.5

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

28+```

29+

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

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

32+`createSchemaIfNotExists`.

33+

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

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

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

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

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

39+

40+**Top-level statements**

41+

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

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

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

45+will be discussed in the next section.

46+

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

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

49+type families.

50+

51+```

52+type family Query_

53+ (schemas :: SchemasType)

54+ (parameters :: Type)

55+ (row :: Type) where

56+ Query_ schemas params row =

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

58+```

59+

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

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

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

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

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

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

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

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

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

69+only a scope for common table expressions.

70+

71+**Subquery expressions**

72+

73+Previous versions of Squeal offered subquery expression support

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

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

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

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

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

79+for a query was not available.

80+

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

82+

83+```Haskell

84+newtype Query

85+ (outer :: FromType)

86+ (commons :: FromType)

87+ (schemas :: SchemasType)

88+ (params :: [NullityType])

89+ (row :: RowType)

90+ = UnsafeQuery { renderQuery :: ByteString }

91+```

92+

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

94+

95+```Haskell

96+exists

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

98+ -> Condition outer commons grp schemas params from

99+```

100+

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

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

103+

104+```Haskell

105+in_

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

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

108+ -> Condition outer commons grp schemas params from

109+```

110+

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

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

113+the next section.

114+

115+```Haskell

116+subAll

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

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

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

120+ -> Condition outer commons grp schemas params from

121+

122+subAny

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

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

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

126+ -> Condition outer commons grp schemas params from

127+```

128+

129+**Expression RankNTypes**

130+

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

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

133+that cannot reference any aliases or parameters.

134+

135+```Haskell

136+type Expr x

137+ = forall outer commons grp schemas params from

138+ . Expression outer commons grp schemas params from x

139+```

140+

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

142+type `(->)`.

143+

144+```Haskell

145+type (-->) x y

146+ = forall outer commons grp schemas params from

147+ . Expression outer commons grp schemas params from x

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

149+```

150+

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

152+

153+```Haskell

154+type Operator x1 x2 y

155+ = forall outer commons grp schemas params from

156+ . Expression outer commons grp schemas params from x1

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

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

159+```

160+

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

162+and variadic functions.

163+

164+```

165+type FunctionN xs y

166+ = forall outer commons grp schemas params from

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

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

169+```

170+

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

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

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

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

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

176+

177+**Selections**

178+

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

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

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

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

183+

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

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

186+

187+```Haskell

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

189+ Star

190+ :: HasUnique tab from row

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

192+ DotStar

193+ :: Has tab from row

194+ => Alias tab

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

196+ List

197+ :: SListI row

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

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

200+ Over

201+ :: SListI row

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

203+ -> WindowDefinition outer commons grp schemas params from

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

205+ Also

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

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

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

209+```

210+

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

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

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

214+window functions, described in the next section.

215+

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

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

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

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

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

221+functions to filter out duplicate rows.

222+

223+**Query clauses**

224+

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

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

227+

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

229+

230+```

231+-- Squeal 0.4

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

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

234+

235+-- Squeal 0.5

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

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

238+```

239+

240+**Window functions and aggregation**

241+

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

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

244+previous section.

245+

246+```Haskell

247+Over

248+ :: SListI row

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

250+ -> WindowDefinition outer commons grp schemas params from

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

252+```

253+

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

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

256+clause. For example,

257+

258+```Haskell

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

260+query = select

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

262+ (from (table #tab))

263+```

264+

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

266+

267+```Haskell

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

269+rank = UnsafeWindowFunction "rank()"

270+```

271+

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

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

274+window functions and n-ary window functions.

275+

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

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

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

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

280+

281+```

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

283+ = All (expr ty)

284+ | Distinct (expr ty)

285+```

286+

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

288+while window functions bear no such distinction.

289+

290+**Migrations**

291+

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

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

294+run or rewind your migrations.

295+

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

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

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

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

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

301+

302+```Haskell

303+data Migration p schemas0 schemas1 = Migration

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

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

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

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

308+ } deriving (GHC.Generic)

309+```

310+

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

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

313+introduces the `Terminally` type.

314+

315+```Haskell

316+newtype Terminally trans monad x0 x1 = Terminally

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

318+```

319+

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

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

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

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

324+

325+```Haskell

326+pureMigration

327+ :: Migration Definition schemas0 schemas1

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

329+```

330+

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

332+a typeclass, `Migratory`.

333+

334+```

335+class Category p => Migratory p where

336+

337+ migrateUp

338+ :: AlignedList (Migration p) schemas0 schemas1

339+ -> PQ schemas0 schemas1 IO ()

340+

341+ migrateDown

342+ :: AlignedList (Migration p) schemas0 schemas1

343+ -> PQ schemas1 schemas0 IO ()

344+```

345+

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

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

348+

349+**Transactions**

350+

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

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

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

354+`transactionallyRetry` computations, retrying the transaction if

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

356+

357+**Types**

358+

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

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

361+with `createDomain`.

362+

363+**Time**

364+

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

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

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

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

369+differences.

370+

371+**Literals**

372+

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

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

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

376+

377+**Set returning functions**

378+

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

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

381+

382+**Text search**

383+

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

385+

386+**Much more**

387+

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

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

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

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

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

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

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

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

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

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

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

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

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

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

402+

403+### Version 0.4

404+

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

406+support for multidimensional arrays, improves support

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

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

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

410+

411+**Types**

412+

413+Squeal 0.4 renames some kinds to aid intuition:

414+

415+```Haskell

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

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

418+```

419+

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

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

422+a `RowType`.

423+

424+```Haskell

425+data PGType

426+ = ..

427+ | PGvararray NullityType

428+ | PGfixarray Nat NullityType

429+ | PGcomposite RowType

430+```

431+

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

433+

434+```Haskell

435+data PGType = PGbool | ..

436+data NullityType = Null PGType | NotNull PGType

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

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

439+```

440+

441+In another sense, we can embed Haskell types

442+into Postgres types by providing type families:

443+

444+```Haskell

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

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

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

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

449+```

450+

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

452+

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

454+associates some Haskell types to their obvious corresponding Postgres

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

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

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

458+users can make their own type instances.

459+

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

461+thing for Haskell with `Maybe`s:

462+

463+```Haskell

464+type family NullPG hask where

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

466+ NullPG hask = 'NotNull (PG hask)

467+```

468+

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

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

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

472+

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

474+

475+```Haskell

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

477+>>> instance SOP.Generic Person

478+>>> instance SOP.HasDatatypeInfo Person

479+>>> :kind! TuplePG Person

480+TuplePG Person :: [NullityType]

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

482+>>> :kind! RowPG Person

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

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

485+```

486+

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

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

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

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

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

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

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

494+

495+For instance:

496+

497+```Haskell

498+>>> :{

499+let

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

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

502+:}

503+```

504+

505+**Arrays**

506+

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

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

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

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

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

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

513+

514+```Haskell

515+>>> :{

516+data Row = Row

517+ { col1 :: Vector Int16

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

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

520+ } deriving (Eq, GHC.Generic)

521+:}

522+

523+>>> instance Generic Row

524+>>> instance HasDatatypeInfo Row

525+```

526+

527+Define a simple round trip query.

528+

529+```Haskell

530+>>> :{

531+let

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

533+ roundTrip = values_ $

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

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

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

537+:}

538+

539+>>> :set -XOverloadedLists

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

541+>>> :{

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

543+ result <- runQueryParams roundTrip input

544+ Just output <- firstRow result

545+ liftBase . print $ input == output

546+:}

547+True

548+```

549+

550+**Containers**

551+

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

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

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

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

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

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

558+

559+```Haskell

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

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

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

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

564+```

565+

566+Let's see an example:

567+

568+```Haskell

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

570+>>> instance SOP.Generic Schwarma

571+>>> instance SOP.HasDatatypeInfo Schwarma

572+>>>

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

574+>>> instance SOP.Generic Person

575+>>> instance SOP.HasDatatypeInfo Person

576+>>> instance Aeson.FromJSON Person

577+>>> instance Aeson.ToJSON Person

578+```

579+

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

581+

582+```Haskell

583+>>> :{

584+type Schema =

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

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

587+ ]

588+:}

589+

590+>>> :{

591+let

592+ setup :: Definition '[] Schema

593+ setup =

594+ createTypeEnumFrom @Schwarma #schwarma >>>

595+ createTypeCompositeFrom @Person #person

596+:}

597+```

598+

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

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

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

602+

603+```Haskell

604+>>> :{

605+data Row = Row

606+ { schwarma :: Enumerated Schwarma

607+ , person1 :: Composite Person

608+ , person2 :: Json Person

609+ } deriving (Eq, GHC.Generic)

610+:}

611+

612+>>> instance Generic Row

613+>>> instance HasDatatypeInfo Row

614+>>> :{

615+let

616+ input = Row

617+ (Enumerated Chicken)

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

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

620+:}

621+```

622+

623+Once again, define a round trip query.

624+

625+```Haskell

626+>>> :{

627+let

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

629+ roundTrip = values_ $

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

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

632+ parameter @3 json `as` #person2

633+:}

634+```

635+

636+Finally, we can drop our type definitions.

637+

638+```Haskell

639+>>> :{

640+let

641+ teardown :: Definition Schema '[]

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

643+:}

644+```

645+

646+Now let's run it.

647+

648+```Haskell

649+>>> :{

650+let

651+ session = do

652+ result <- runQueryParams roundTrip input

653+ Just output <- firstRow result

654+ liftBase . print $ input == output

655+in

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

657+ define setup

658+ & pqThen session

659+ & pqThen (define teardown)

660+:}

661+True

662+```

663+

664+**With**

665+

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

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

668+

669+```Haskell

670+with

671+ :: SOP.SListI commons

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

673+ -- ^ common table expressions

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

675+ -> Manipulation schema params results

676+```

677+

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

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

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

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

682+

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

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

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

686+

687+```Haskell

688+data CommonTableExpression statement params schema0 schema1 where

689+ CommonTableExpression

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

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

692+```

693+

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

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

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

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

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

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

700+

701+```Haskell

702+class With statement where

703+ with

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

705+ -> statement schema1 params row

706+ -> statement schema0 params row

707+```

708+

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

710+

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

712+

713+```Haskell

714+>>> :{

715+let

716+ query :: Query

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

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

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

720+ '[]

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

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

723+ query = with (

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

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

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

727+in printSQL query

728+:}

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

730+

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

732+

733+>>> :{

734+let

735+ manipulation :: Manipulation

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

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

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

739+ manipulation = with

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

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

742+in printSQL manipulation

743+:}

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

745+```

746+

747+**Three Valued Logic**

748+

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

750+of `true` and `false`.

751+

752+```Haskell

753+-- Squeal 0.3

754+type Condition schema from grouping params =

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

756+```

757+

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

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

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

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

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

763+

764+```Haskell

765+-- Squeal 0.4

766+type Condition schema from grouping params =

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

768+```

769+

770+**Subquery Expressions**

771+

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

773+

774+**Row Types**

775+

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

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

778+`typedef`.

779+

780+**Runtime Exceptions**

781+

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

783+encountered and handler functions.

784+

785+```Haskell

786+data SquealException

787+ = PQException

788+ { sqlExecStatus :: LibPQ.ExecStatus

789+ , sqlStateCode :: Maybe ByteString

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

791+ , sqlErrorMessage :: Maybe ByteString

792+ }

793+ | ResultException Text

794+ | ParseException Text

795+ deriving (Eq, Show)

796+instance Exception SquealException

797+

798+catchSqueal

799+ :: MonadBaseControl IO io

800+ => io a

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

802+ -> io a

803+

804+handleSqueal

805+ :: MonadBaseControl IO io

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

807+ -> io a -> io a

808+```

809+

810+**Additional Changes**

811+

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

813+and array expressions.

814+

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

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

817+

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

819+Please consult the documentation.

820+

821+### Version 0.3.2 - August 4, 2018

822+

823+Version 0.3.2 features extensive support for `JSON` functionality with

824+more than 50 new functions.

825+This work is entirely due to [Mike Ledger](https://github.com/mikeplus64)

826+who has been making terrific contributions to Squeal. Thanks!

827+We also got some examples in the documentation for pools submitted by

828+[Raveline](https://github.com/Raveline). I'm so pleased to be

829+getting pull requests and issue submissions from you all!

830+

831+### Version 0.3.1 - July 7, 2018

832+

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

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

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

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

837+There were a couple minor name changes, i.e. the function `group` was renamed to `groupBy`.

838+Please consult the documentation.

839+

3### Version 0.3 - June 26, 2018

840### Version 0.3 - June 26, 2018

841

5Version 0.3 of Squeal adds views as well as composite and enumerated types to Squeal.

842Version 0.3 of Squeal adds views as well as composite and enumerated types to Squeal.

@@ -97,7 +934,7 @@ let

97CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');

934CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');

98```

935```

936

100−Enumerated types can also be generated from a Haskell algbraic data type with nullary constructors, for example:

937+Enumerated types can also be generated from a Haskell algebraic data type with nullary constructors, for example:

101

938

102```Haskell

939```Haskell

103>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

940>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

scrap-your-nils.mdnew file+60

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

1+## Scrap your Nils

3+One of the most useful types I've come across in Haskell is the type of

4+"heterogeneous lists". This is the same as the [Rec](http://hackage.haskell.org/package/vinyl-0.8.1.1/docs/Data-Vinyl-Core.html)

5+datatype from the [vinyl](http://hackage.haskell.org/package/vinyl) library.

6+It's also the same as the [NP](http://hackage.haskell.org/package/generics-sop-0.3.2.0/docs/Generics-SOP-NP.html)

7+datatype from the [generics-sop](http://hackage.haskell.org/package/generics-sop) library.

8+Squeal makes heavy use of this type.

10+```Haskell

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

12+>>> :i NP

13+type role NP representational nominal

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

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

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

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

18+ -- Defined in ‘Generics.SOP.NP’

19+```

20+

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

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

23+

24+```Haskell

25+>>> :set -XDataKinds

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

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

28+>>> example

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

30+```

31+

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

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

34+of the aliases themselves at the type level.

35+

36+```Haskell

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

38+>>> import GHC.TypeLits

39+>>> import GHC.OverloadedLabels

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

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

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

43+```

44+

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

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

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

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

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

50+the last label as a list.

51+

52+```Haskell

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

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

55+```

56+

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

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

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

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

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

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

12module Main (main, main2) where

14−import Control.Monad (void)

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

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

16import Data.Int (Int16, Int32)

15import Data.Int (Int16, Int32)

17import Data.Monoid ((<>))

16import Data.Monoid ((<>))

18import Data.Text (Text)

17import Data.Text (Text)

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

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

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

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

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

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

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

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

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

33 ])

32 ])

34 , "emails" ::: 'Table (

33 , "emails" ::: 'Table (

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

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

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

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

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

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

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

41 ])

40 ])

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

42 ]

44+type Schemas = Public Schema

45+

44−setup :: Definition '[] Schema

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

45−setup =

47+setup =

46 createTable #users

48 createTable #users

47− ( serial `As` #id :*

49+ ( serial `as` #id :*

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

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

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

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

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

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

51 >>>

53 >>>

52 createTable #emails

54 createTable #emails

53− ( serial `As` #id :*

55+ ( serial `as` #id :*

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

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

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

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

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

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

57 foreignKey #user_id #users #id

59 foreignKey #user_id #users #id

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

60+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

59−

61+ >>>

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

63+

60−teardown :: Definition Schema '[]

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

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

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

62−

66+

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

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

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

65−insertUser = insertRows #users

68+insertUser = insertInto #users

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

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

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

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

68−

71+

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

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

70−insertEmail = insertRows #emails

73+insertEmail = insertInto_ #emails

71− ( Default `As` #id :*

72− Set (param @1) `As` #user_id :*

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

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

75+

74− OnConflictDoNothing (Returning Nil)

76+getUsers :: Query_ Schemas () User

75−

76−getUsers :: Query Schema '[]

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

78− , "userEmail" ::: 'Null 'PGtext

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

80−getUsers = select

77+getUsers = select_

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

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

82− ( from (table (#users `As` #u)

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

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

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

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

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

86−data User = User { userName :: Text, userEmail :: Maybe Text, userVec :: Vector (Maybe Int16) }

83+data User = User { userName :: Text, userEmail :: Maybe Text, userVec :: VarArray (Vector (Maybe Int16)) }

87 deriving (Show, GHC.Generic)

84 deriving (Show, GHC.Generic)

88instance SOP.Generic User

85instance SOP.Generic User

89instance SOP.HasDatatypeInfo User

86instance SOP.HasDatatypeInfo User

91users :: [User]

88users :: [User]

92−users =

89+users =

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

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

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

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

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

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

96 ]

93 ]

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

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

99session = do

96session = do

100− liftBase $ Char8.putStrLn "manipulating"

97+ liftIO $ Char8.putStrLn "manipulating"

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

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

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

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

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

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

104− liftBase $ Char8.putStrLn "querying"

101+ liftIO $ Char8.putStrLn "querying"

105 usersResult <- runQuery getUsers

102 usersResult <- runQuery getUsers

106 usersRows <- getRows usersResult

103 usersRows <- getRows usersResult

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

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

108

105

109main :: IO ()

106main :: IO ()

110main = do

107main = do

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

122

119

123main2 :: IO ()

120main2 :: IO ()

124main2 =

121main2 =

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

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

126 define setup

123 define setup

127 & pqThen session

124 & pqThen session

128 & pqThen (define teardown)

125 & pqThen (define teardown)

squeal-postgresql/squeal-postgresql.cabal+71−11

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

1name: squeal-postgresql

2−version: 0.3.0.0

2+version: 0.5.1.0

3synopsis: Squeal PostgreSQL Library

4description: Squeal is a type-safe embedding of PostgreSQL in Haskell

5homepage: https://github.com/morphismtech/squeal

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

22 hs-source-dirs: src

23 exposed-modules:

24 Squeal.PostgreSQL

25+ Squeal.PostgreSQL.Alias

25 Squeal.PostgreSQL.Binary

26 Squeal.PostgreSQL.Binary

26 Squeal.PostgreSQL.Definition

27 Squeal.PostgreSQL.Definition

28+ Squeal.PostgreSQL.Definition.Function

29+ Squeal.PostgreSQL.Definition.Index

30+ Squeal.PostgreSQL.Definition.Table

31+ Squeal.PostgreSQL.Definition.Table.Constraint

32+ Squeal.PostgreSQL.Definition.Type

33+ Squeal.PostgreSQL.Definition.Schema

34+ Squeal.PostgreSQL.Definition.View

27 Squeal.PostgreSQL.Expression

35 Squeal.PostgreSQL.Expression

36+ Squeal.PostgreSQL.Expression.Aggregate

37+ Squeal.PostgreSQL.Expression.Collection

38+ Squeal.PostgreSQL.Expression.Comparison

39+ Squeal.PostgreSQL.Expression.Json

40+ Squeal.PostgreSQL.Expression.Literal

41+ Squeal.PostgreSQL.Expression.Logic

42+ Squeal.PostgreSQL.Expression.Math

43+ Squeal.PostgreSQL.Expression.Null

44+ Squeal.PostgreSQL.Expression.Parameter

45+ Squeal.PostgreSQL.Expression.Range

46+ Squeal.PostgreSQL.Expression.Set

47+ Squeal.PostgreSQL.Expression.Sort

48+ Squeal.PostgreSQL.Expression.Subquery

49+ Squeal.PostgreSQL.Expression.Text

50+ Squeal.PostgreSQL.Expression.TextSearch

51+ Squeal.PostgreSQL.Expression.Time

52+ Squeal.PostgreSQL.Expression.Type

53+ Squeal.PostgreSQL.Expression.Window

54+ Squeal.PostgreSQL.List

28 Squeal.PostgreSQL.Manipulation

55 Squeal.PostgreSQL.Manipulation

29 Squeal.PostgreSQL.Migration

56 Squeal.PostgreSQL.Migration

30 Squeal.PostgreSQL.Pool

57 Squeal.PostgreSQL.Pool

58+ Squeal.PostgreSQL.PG

31 Squeal.PostgreSQL.PQ

59 Squeal.PostgreSQL.PQ

32 Squeal.PostgreSQL.Render

60 Squeal.PostgreSQL.Render

33 Squeal.PostgreSQL.Query

61 Squeal.PostgreSQL.Query

@@ -37,40 +65,73 @@ library

37 ghc-options: -Wall

65 ghc-options: -Wall

38 build-depends:

66 build-depends:

39 aeson >= 1.2.4.0

67 aeson >= 1.2.4.0

40− , base >= 4.10.1.0 && < 5.0

68+ , base >= 4.11.1.0 && < 5.0

41 , binary-parser >= 0.5.5

69 , binary-parser >= 0.5.5

42 , bytestring >= 0.10.8.2

70 , bytestring >= 0.10.8.2

43 , bytestring-strict-builder >= 0.4.5

71 , bytestring-strict-builder >= 0.4.5

44 , deepseq >= 1.4.3.0

72 , deepseq >= 1.4.3.0

73+ , free-categories >= 0.1.0.0

45− , generics-sop >= 0.3.2.0

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

46− , lifted-base >= 0.2.3.12

47 , mmorph >= 1.1.1

75 , mmorph >= 1.1.1

48− , monad-control >= 1.0.2.3

49 , mtl >= 2.2.2

76 , mtl >= 2.2.2

50 , network-ip >= 0.3.0.2

77 , network-ip >= 0.3.0.2

51 , postgresql-binary >= 0.12.1

78 , postgresql-binary >= 0.12.1

52 , postgresql-libpq >= 0.9.4.1

79 , postgresql-libpq >= 0.9.4.1

53− , profunctors >= 5.2.2

80+ , records-sop >= 0.1.0.0

54 , resource-pool >= 0.2.3.2

81 , resource-pool >= 0.2.3.2

55 , scientific >= 0.3.5.3

82 , scientific >= 0.3.5.3

56 , text >= 1.2.3.0

83 , text >= 1.2.3.0

57 , time >= 1.8.0.2

84 , time >= 1.8.0.2

58 , transformers >= 0.5.2.0

85 , transformers >= 0.5.2.0

59− , transformers-base >= 0.4.4

86+ , unliftio >= 0.2.10

87+ , unliftio-pool >= 0.2.1.0

60 , uuid-types >= 1.0.3

88 , uuid-types >= 1.0.3

61 , vector >= 0.12.0.1

89 , vector >= 0.12.0.1

63−test-suite squeal-postgresql-doctest

91+test-suite doctest

64 default-language: Haskell2010

92 default-language: Haskell2010

65 type: exitcode-stdio-1.0

93 type: exitcode-stdio-1.0

66 hs-source-dirs: test

94 hs-source-dirs: test

67 ghc-options: -Wall

95 ghc-options: -Wall

68− main-is: DocTest.hs

96+ main-is: Doc.hs

69 build-depends:

97 build-depends:

70 base >= 4.10.0.0

98 base >= 4.10.0.0

71 , doctest >= 0.11.4

99 , doctest >= 0.11.4

100+ , squeal-postgresql

101+

102+test-suite properties

103+ default-language: Haskell2010

104+ type: exitcode-stdio-1.0

105+ hs-source-dirs: test

106+ ghc-options: -Wall

107+ main-is: Property.hs

108+ build-depends:

109+ base >= 4.10.0.0

110+ , bytestring >= 0.10.8.2

111+ , hedgehog >= 1.0

112+ , mtl >= 2.2.2

113+ , scientific >= 0.3.5.3

114+ , squeal-postgresql

115+ , time >= 1.8.0.2

116+

117+test-suite spec

118+ default-language: Haskell2010

119+ type: exitcode-stdio-1.0

120+ hs-source-dirs: test

121+ ghc-options: -Wall

122+ main-is: Spec.hs

123+ build-depends:

124+ base >= 4.10.0.0

125+ , async >= 2.2.2

126+ , bytestring >= 0.10.8.2

127+ , generics-sop >= 0.3.1.0

128+ , hspec >= 2.4.8

129+ , mtl >= 2.2.2

130+ , squeal-postgresql

131+ , text >= 1.2.2.2

132+ , vector >= 0.12.0.1

133

73−executable squeal-postgresql-example

134+executable example

74 default-language: Haskell2010

135 default-language: Haskell2010

75 hs-source-dirs: exe

136 hs-source-dirs: exe

76 ghc-options: -Wall

137 ghc-options: -Wall

@@ -83,5 +144,4 @@ executable squeal-postgresql-example

83 , squeal-postgresql

144 , squeal-postgresql

84 , text >= 1.2.2.2

145 , text >= 1.2.2.2

85 , transformers >= 0.5.2.0

146 , transformers >= 0.5.2.0

86− , transformers-base >= 0.4.4

87 , vector >= 0.12.0.1

147 , vector >= 0.12.0.1

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

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

1{-|

2Module: Squeal.PostgreSQL

3−Description: Squeel export module

3+Description: Squeal export module

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

5Maintainer: eitan@morphism.tech

6Stability: experimental

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

11First, we need some language extensions because Squeal uses modern GHC

12features.

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

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

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

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

16−

16+

17We'll need some imports.

19−>>> import Control.Monad (void)

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

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

21>>> import Data.Int (Int32)

20>>> import Data.Int (Int32)

22>>> import Data.Text (Text)

21>>> import Data.Text (Text)

23>>> import Squeal.PostgreSQL

22>>> import Squeal.PostgreSQL

24−>>> import Squeal.PostgreSQL.Render

26We'll use generics to easily convert between Haskell and PostgreSQL values.

24We'll use generics to easily convert between Haskell and PostgreSQL values.

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

32we use @DataKinds@ and @TypeOperators@.

30we use @DataKinds@ and @TypeOperators@.

34>>> :{

32>>> :{

33+type UsersColumns =

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

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

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

37+type EmailsColumns =

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

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

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

41+type EmailsConstraints =

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

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

35type Schema =

44type Schema =

36− '[ "users" ::: 'Table (

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

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

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

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

40− ])

41− , "emails" ::: 'Table (

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

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

47+type Schemas = Public Schema

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

44− ] :=>

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

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

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

48− ])

49− ]

50:}

48:}

52Notice the use of type operators.

50Notice the use of type operators.

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

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

55a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's @::@

53a `TableConstraint` or a `ColumnType`. It is intended to connote Haskell's @::@

56operator.

54operator.

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

60yielding a `ColumnType`. It is intended to connote Haskell's @=>@ operator

58yielding a `ColumnType`. It is intended to connote Haskell's @=>@ operator

62Next, we'll write `Definition`s to set up and tear down the schema. In

60Next, we'll write `Definition`s to set up and tear down the schema. In

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

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

64has two type parameters, corresponding to the schema

62has two type parameters, corresponding to the schema

65before being run and the schema after. We can compose definitions using `>>>`.

63before being run and the schema after. We can compose definitions using `>>>`.

66Here and in the rest of our commands we make use of overloaded

64Here and in the rest of our commands we make use of overloaded

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

69>>> :{

67>>> :{

70let

68let

71− setup :: Definition '[] Schema

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

72− setup =

70+ setup =

73 createTable #users

71 createTable #users

74− ( serial `As` #id :*

72+ ( serial `as` #id :*

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

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

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

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

77 createTable #emails

75 createTable #emails

78− ( serial `As` #id :*

76+ ( serial `as` #id :*

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

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

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

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

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

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

82 foreignKey #user_id #users #id

80 foreignKey #user_id #users #id

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

81+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

84:}

82:}

86We can easily see the generated SQL is unsurprising looking.

84We can easily see the generated SQL is unsurprising looking.

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

89CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));

87CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));

90CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

88CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

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

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

93In our `createTable` commands we included `TableConstraint`s to define

91In our `createTable` commands we included `TableConstraint`s to define

94primary and foreign keys, making them somewhat complex. Our @teardown@

92primary and foreign keys, making them somewhat complex. Our @teardown@

95`Definition` is simpler.

93`Definition` is simpler.

97>>> :{

95>>> :{

98let

96let

99− teardown :: Definition Schema '[]

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

100 teardown = dropTable #emails >>> dropTable #users

98 teardown = dropTable #emails >>> dropTable #users

101:}

99:}

102

100

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

104DROP TABLE "emails";

102DROP TABLE "emails";

105DROP TABLE "users";

103DROP TABLE "users";

106

104

105+We'll need a Haskell type for @User@s. We give the type `Generics.SOP.Generic` and

106+`Generics.SOP.HasDatatypeInfo` instances so that we can encode and decode @User@s.

107+

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

109+>>> instance SOP.Generic User

110+>>> instance SOP.HasDatatypeInfo User

111+

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

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

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

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

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

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

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

115+and an output row. When

111we insert into the users table, we will need a parameter for the @name@

116we insert into the users table, we will need a parameter for the @name@

112field but not for the @id@ field. Since it's serial, we can use a default

117field but not for the @id@ field. Since it's serial, we can use a default

113value. However, since the emails table refers to the users table, we will

118value. However, since the emails table refers to the users table, we will

114need to retrieve the user id that the insert generates and insert it into

119need to retrieve the user id that the insert generates and insert it into

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

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

116−of our inserts.

121+`with` statement.

117−

118−>>> :{

119−let

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

121− insertUser = insertRow #users

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

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

124−:}

125

122

126>>> :{

123>>> :{

127let

124let

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

125+ insertUser :: Manipulation_ Schemas User ()

129− insertEmail = insertRow #emails

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

127+ where

128+ u = insertInto #users

130− ( Default `As` #id :*

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

131− Set (param @1) `As` #user_id :*

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

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

131+ e = insertInto_ #emails $ Select

133− OnConflictDoNothing (Returning Nil)

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

133+ (from (common #u))

134:}

135

136>>> printSQL insertUser

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

137+WITH "u" AS (INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) RETURNING "id" AS "id", ($2 :: text) AS "email") INSERT INTO "emails" ("user_id", "email") SELECT "u"."id", "u"."email" FROM "u" AS "u"

138−>>> printSQL insertEmail

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

140

138

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

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

142interested in the ids here, just the usernames and email addresses. We

140interested in the ids here, just the usernames and email addresses. We

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

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

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

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

145

143

146>>> :{

144>>> :{

147let

145let

148− getUsers :: Query Schema '[]

146+ getUsers :: Query_ Schemas () User

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

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

151− getUsers = select

147+ getUsers = select_

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

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

153− ( from (table (#users `As` #u)

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

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

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

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

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

156:}

152:}

157

153

158>>> printSQL getUsers

154>>> printSQL getUsers

159SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

155SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

160

156

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

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

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

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

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

166−

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

168−>>> instance SOP.Generic User

169−>>> instance SOP.HasDatatypeInfo User

170−

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

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

172

158

173>>> :{

159>>> :{

174let

160let

175 users :: [User]

161 users :: [User]

176− users =

162+ users =

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

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

178 , User "Bob" Nothing

164 , User "Bob" Nothing

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

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

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

190

176

191>>> :{

177>>> :{

192let

178let

193− session :: PQ Schema Schema IO ()

179+ session :: PQ Schemas Schemas IO ()

194 session = do

180 session = do

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

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

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

181+ _ <- traversePrepared_ insertUser users

198 usersResult <- runQuery getUsers

182 usersResult <- runQuery getUsers

199 usersRows <- getRows usersResult

183 usersRows <- getRows usersResult

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

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

201in

185in

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

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

203 define setup

187 define setup

204 & pqThen session

188 & pqThen session

205 & pqThen (define teardown)

189 & pqThen (define teardown)

206:}

190:}

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

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

208-}

192-}

209−module Squeal.PostgreSQL

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

210− ( module Squeal.PostgreSQL.Binary

194+

211− , module Squeal.PostgreSQL.Definition

212− , module Squeal.PostgreSQL.Expression

213− , module Squeal.PostgreSQL.Manipulation

214− , module Squeal.PostgreSQL.PQ

215− , module Squeal.PostgreSQL.Query

216− , module Squeal.PostgreSQL.Schema

217− , module Squeal.PostgreSQL.Transaction

218− ) where

219−

220−import Squeal.PostgreSQL.Binary

195+import Squeal.PostgreSQL.Alias as X

196+import Squeal.PostgreSQL.Binary as X

221−import Squeal.PostgreSQL.Definition

197+import Squeal.PostgreSQL.Definition as X

198+import Squeal.PostgreSQL.Definition.Function as X

199+import Squeal.PostgreSQL.Definition.Index as X

200+import Squeal.PostgreSQL.Definition.Schema as X

201+import Squeal.PostgreSQL.Definition.Table as X

202+import Squeal.PostgreSQL.Definition.Table.Constraint as X

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

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

222−import Squeal.PostgreSQL.Expression

205+import Squeal.PostgreSQL.Expression as X

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

224+import Squeal.PostgreSQL.List as X

223−import Squeal.PostgreSQL.Manipulation

225+import Squeal.PostgreSQL.Manipulation as X

226+import Squeal.PostgreSQL.Migration as X

227+import Squeal.PostgreSQL.PG as X

228+import Squeal.PostgreSQL.Pool as X

224−import Squeal.PostgreSQL.PQ

229+import Squeal.PostgreSQL.PQ as X

225−import Squeal.PostgreSQL.Query

230+import Squeal.PostgreSQL.Query as X

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

226−import Squeal.PostgreSQL.Schema

232+import Squeal.PostgreSQL.Schema as X

227−import Squeal.PostgreSQL.Transaction

233+import Squeal.PostgreSQL.Transaction as X

squeal-postgresql/src/Squeal/PostgreSQL/Alias.hsnew file+249

@@ -0,0 +1,249 @@

1+{-|

2+Module: Squeal.PostgreSQL.Alias

3+Description: Aliases

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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

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

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

11+-}

12+

13+{-# LANGUAGE

14+ AllowAmbiguousTypes

15+ , ConstraintKinds

16+ , DeriveAnyClass

17+ , DeriveGeneric

18+ , FlexibleContexts

19+ , FlexibleInstances

20+ , FunctionalDependencies

21+ , GADTs

22+ , LambdaCase

23+ , OverloadedStrings

24+ , QuantifiedConstraints

25+ , RankNTypes

26+ , ScopedTypeVariables

27+ , StandaloneDeriving

28+ , TypeApplications

29+ , TypeFamilyDependencies

30+ , TypeInType

31+ , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

34+#-}

35+

36+module Squeal.PostgreSQL.Alias

37+ ( (:::)

38+ , Alias (..)

39+ , IsLabel (..)

40+ , Aliased (As)

41+ , Aliasable (as)

42+ , renderAliased

43+ , Has

44+ , HasUnique

45+ , HasAll

46+ , HasIn

47+ , QualifiedAlias (..)

48+ , IsQualified (..)

49+ -- * Grouping

50+ , Grouping (..)

51+ , GroupedBy

52+ ) where

53+

54+import Control.DeepSeq

55+import Data.ByteString (ByteString)

56+import Data.String (fromString)

57+import GHC.OverloadedLabels

58+import GHC.TypeLits

59+

60+import qualified Generics.SOP as SOP

61+import qualified GHC.Generics as GHC

62+

63+import Squeal.PostgreSQL.List

64+import Squeal.PostgreSQL.Render

65+

66+-- $setup

67+-- >>> import Squeal.PostgreSQL

68+

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

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

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

72+infixr 6 :::

73+

74+

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

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

77+-- for typesafe aggregation

78+data Grouping

79+ = Ungrouped -- ^ no aggregation permitted

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

81+

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

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

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

85+-}

86+class (KnownSymbol table, KnownSymbol column)

87+ => GroupedBy table column bys where

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

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

90+instance {-# OVERLAPPABLE #-}

91+ ( KnownSymbol table

92+ , KnownSymbol column

93+ , GroupedBy table column bys

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

95+

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

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

98+--

99+-- >>> :set -XOverloadedLabels

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

101+-- Alias

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

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

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

105+ fromLabel = Alias

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

107+ fromLabel = fromLabel SOP.:* Nil

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

109+-- "jimbob"

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

111+ renderSQL = doubleQuoted . fromString . symbolVal

112+

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

114+-- "jimbob", "kandi"

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

116+ renderSQL

117+ = commaSeparated

118+ . SOP.hcollapse

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

120+

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

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

123+--

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

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

126+data Aliased expression aliased where

127+ As

128+ :: KnownSymbol alias

129+ => expression ty

130+ -> Alias alias

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

132+deriving instance Show (expression ty)

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

134+deriving instance Eq (expression ty)

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

136+deriving instance Ord (expression ty)

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

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

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

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

141+

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

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

144+class KnownSymbol alias => Aliasable alias expression aliased

145+ | aliased -> expression

146+ , aliased -> alias

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

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

149+ (expression ty)

150+ (Aliased expression aliased)

151+ where

152+ as = As

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

154+ (expression ty)

155+ (NP (Aliased expression) tys)

156+ where

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

158+

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

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

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

162+renderAliased

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

164+ -> Aliased expression aliased

165+ -> ByteString

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

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

168+

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

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

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

172+

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

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

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

176+class KnownSymbol alias =>

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

178+ | alias fields -> field where

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

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

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

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

183+

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

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

186+choose which subfields to update.

187+-}

188+class HasIn fields field where

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

190+

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

192+-- a list of @subfields@.

193+class

194+ ( SOP.All KnownSymbol aliases

195+ ) => HasAll

196+ (aliases :: [Symbol])

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

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

199+ | aliases fields -> subfields where

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

201+instance {-# OVERLAPPABLE #-}

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

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

204+

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

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

207+-- by a table alias.

208+class IsQualified table column expression where

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

210+ infixl 9 !

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

212+

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

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

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

216+a qualifier of @public@ is provided.

217+

218+>>> :{

219+let

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

221+ alias1 = #sch ! #tab

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

223+ alias2 = #vw

224+in printSQL alias1 >> printSQL alias2

225+:}

226+"sch"."tab"

227+"vw"

228+-}

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

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

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

232+ _!_ = QualifiedAlias

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

234+ fromLabel = QualifiedAlias

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

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

237+ _!_ = QualifiedAlias `As` Alias

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

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

240+ fromLabel = QualifiedAlias `As` Alias

241+

242+instance (KnownSymbol q, KnownSymbol a)

243+ => RenderSQL (QualifiedAlias q a) where

244+ renderSQL _ =

245+ let

246+ qualifier = renderSQL (Alias @q)

247+ alias = renderSQL (Alias @a)

248+ in

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

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

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

8This 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

11do not need to define your own instances to decode retrieved rows into Haskell values or

12to encode Haskell values into statement parameters.

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

15+

14>>> import Data.Int (Int16)

16>>> import Data.Int (Int16)

15>>> import Data.Text (Text)

17>>> import Data.Text (Text)

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

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

20+>>> import Squeal.PostgreSQL

21+

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

23+round trip query.

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

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

18>>> instance Generic Row

26>>> instance Generic Row

19>>> instance HasDatatypeInfo Row

27>>> instance HasDatatypeInfo Row

28+>>> :{

29+let

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

31+ roundTrip = values_ $

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

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

34+ parameter @3 bool `as` #col3

35+:}

21−>>> import Control.Monad (void)

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

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

38+the input and output should be equal.

23−>>> import Squeal.PostgreSQL

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

25>>> :{

41>>> :{

26−let

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

27− query :: Query '[]

43+ result <- runQueryParams roundTrip input

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

44+ Just output <- firstRow result

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

45+ liftIO . print $ input == output

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

31:}

46:}

47+True

48+

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

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

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

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

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

54+create multi-dimensional fixed length arrays.

55+

56+>>> :{

57+data Row = Row

58+ { col1 :: VarArray (Vector Int16)

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

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

61+ } deriving (Eq, GHC.Generic)

62+:}

63+

64+>>> instance Generic Row

65+>>> instance HasDatatypeInfo Row

66+

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

33>>> :{

69>>> :{

34let

70let

35− roundtrip :: IO ()

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

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

72+ roundTrip = values_ $

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

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

38− Just row <- firstRow result

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

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

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

40:}

76:}

42−>>> roundtrip

78+>>> :set -XOverloadedLists

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

80+>>> :{

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

82+ result <- runQueryParams roundTrip input

83+ Just output <- firstRow result

84+ liftIO . print $ input == output

85+:}

43True

86True

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

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

47−Postgres enumerated and composite types.

48−

49Enumerated (enum) types are data types that comprise a static, ordered set of values.

88Enumerated (enum) types are data types that comprise a static, ordered set of values.

50They are equivalent to Haskell algebraic data types whose constructors are nullary.

89They are equivalent to Haskell algebraic data types whose constructors are nullary.

51An example of an enum type might be the days of the week,

90An example of an enum type might be the days of the week,

52or a set of status values for a piece of data.

91or a set of status values for a piece of data.

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

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

55>>> instance Generic Schwarma

94>>> instance Generic Schwarma

56>>> instance HasDatatypeInfo Schwarma

95>>> instance HasDatatypeInfo Schwarma

58A composite type represents the structure of a row or record;

97A composite type represents the structure of a row or record;

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

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

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

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

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

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

64>>> instance Generic Person

101>>> instance Generic Person

65>>> instance HasDatatypeInfo Person

102>>> instance HasDatatypeInfo Person

103+>>> instance Aeson.FromJSON Person

104+>>> instance Aeson.ToJSON Person

105

67We can create the equivalent Postgres types directly from their Haskell types.

106We can create the equivalent Postgres types directly from their Haskell types.

107

69>>> :{

108>>> :{

70type Schema =

109type Schema =

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

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

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

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

73 ]

112 ]

74:}

113:}

114

76>>> :{

115>>> :{

77let

116let

78− setup :: Definition '[] Schema

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

79 setup =

118 setup =

80 createTypeEnumFrom @Schwarma #schwarma >>>

119 createTypeEnumFrom @Schwarma #schwarma >>>

81 createTypeCompositeFrom @Person #person

120 createTypeCompositeFrom @Person #person

82:}

121:}

122

84−Then we can perform roundtrip queries;

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

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

125+@Row@ type using the `Enumerated`, `Composite` and `Json` newtypes as fields.

126

127+>>> :{

128+data Row = Row

129+ { schwarma :: Enumerated Schwarma

130+ , person1 :: Composite Person

131+ , person2 :: Json Person

132+ } deriving (Eq, GHC.Generic)

133+:}

134+

135+>>> instance Generic Row

136+>>> instance HasDatatypeInfo Row

86>>> :{

137>>> :{

87let

138let

88− querySchwarma :: Query Schema

139+ input = Row

89− '[ 'NotNull (EnumFrom Schwarma)]

140+ (Enumerated Chicken)

90− '["fromOnly" ::: 'NotNull (EnumFrom Schwarma)]

141+ (Composite (Person "Faisal" 24))

91− querySchwarma = values_ (parameter @1 #schwarma `As` #fromOnly)

142+ (Json (Person "Ahmad" 48))

92:}

143:}

144

145+Once again, define a round trip query.

146+

94>>> :{

147>>> :{

95let

148let

96− queryPerson :: Query Schema

149+ roundTrip :: Query_ (Public Schema) Row Row

97− '[ 'NotNull (CompositeFrom Person)]

150+ roundTrip = values_ $

98− '["fromOnly" ::: 'NotNull (CompositeFrom Person)]

151+ parameter @1 (typedef #schwarma) `as` #schwarma :*

99− queryPerson = values_ (parameter @1 #person `As` #fromOnly :* Nil)

152+ parameter @2 (typedef #person) `as` #person1 :*

153+ parameter @3 json `as` #person2

100:}

154:}

101

155

102−And finally drop the types.

156+Finally, we can drop our type definitions.

103

157

104>>> :{

158>>> :{

105let

159let

106− teardown :: Definition Schema '[]

160+ teardown :: Definition (Public Schema) (Public '[])

107 teardown = dropType #schwarma >>> dropType #person

161 teardown = dropType #schwarma >>> dropType #person

108:}

162:}

109

163

@@ -112,20 +166,16 @@ Now let's run it.

112>>> :{

166>>> :{

113let

167let

114 session = do

168 session = do

115− result1 <- runQueryParams querySchwarma (Only Chicken)

169+ result <- runQueryParams roundTrip input

116− Just (Only schwarma) <- firstRow result1

170+ Just output <- firstRow result

117− liftBase $ print (schwarma :: Schwarma)

171+ liftIO . print $ input == output

118− result2 <- runQueryParams queryPerson (Only (Person (Just "Faisal") (Just 24)))

119− Just (Only person) <- firstRow result2

120− liftBase $ print (person :: Person)

121in

172in

122− void . withConnection "host=localhost port=5432 dbname=exampledb" $

173+ withConnection "host=localhost port=5432 dbname=exampledb" $

123 define setup

174 define setup

124 & pqThen session

175 & pqThen session

125 & pqThen (define teardown)

176 & pqThen (define teardown)

126:}

177:}

127−Chicken

178+True

128−Person {name = Just "Faisal", age = Just 24}

129-}

179-}

130

180

131{-# LANGUAGE

181{-# LANGUAGE

@@ -134,55 +184,76 @@ Person {name = Just "Faisal", age = Just 24}

134 , DeriveFunctor

184 , DeriveFunctor

135 , DeriveGeneric

185 , DeriveGeneric

136 , DeriveTraversable

186 , DeriveTraversable

187+ , DefaultSignatures

137 , FlexibleContexts

188 , FlexibleContexts

138 , FlexibleInstances

189 , FlexibleInstances

190+ , FunctionalDependencies

139 , GADTs

191 , GADTs

140 , LambdaCase

192 , LambdaCase

193+ , OverloadedStrings

141 , MultiParamTypeClasses

194 , MultiParamTypeClasses

142 , ScopedTypeVariables

195 , ScopedTypeVariables

143 , TypeApplications

196 , TypeApplications

197+ , TypeFamilies

144 , TypeInType

198 , TypeInType

145 , TypeOperators

199 , TypeOperators

146 , UndecidableInstances

200 , UndecidableInstances

201+ , UndecidableSuperClasses

147#-}

202#-}

148

203

149module Squeal.PostgreSQL.Binary

204module Squeal.PostgreSQL.Binary

150 ( -- * Encoding

205 ( -- * Encoding

151 ToParam (..)

206 ToParam (..)

152− , ToColumnParam (..)

153 , ToParams (..)

207 , ToParams (..)

208+ , ToNullityParam (..)

209+ , ToField (..)

210+ , ToFixArray (..)

154 -- * Decoding

211 -- * Decoding

155 , FromValue (..)

212 , FromValue (..)

156− , FromColumnValue (..)

157 , FromRow (..)

213 , FromRow (..)

214+ , FromField (..)

215+ , FromFixArray (..)

158 -- * Only

216 -- * Only

159 , Only (..)

217 , Only (..)

218+ -- * Oid

219+ , OidOf (..)

220+ , OidOfParam (..)

221+ , OidOfField (..)

160 ) where

222 ) where

161

223

162import BinaryParser

224import BinaryParser

163−import ByteString.StrictBuilder

225+import ByteString.StrictBuilder (builderLength, int32BE, int64BE, word32BE)

164−import Data.Aeson hiding (Null)

226+import Control.Arrow (left)

227+import Control.Monad

165import Data.Int

228import Data.Int

166import Data.Kind

229import Data.Kind

167−import Data.Monoid hiding (All)

168import Data.Scientific

230import Data.Scientific

169import Data.Time

231import Data.Time

170import Data.UUID.Types

232import Data.UUID.Types

171import Data.Vector (Vector)

233import Data.Vector (Vector)

172import Data.Word

234import Data.Word

235+import Foreign.C.Types (CUInt(CUInt))

173import Generics.SOP

236import Generics.SOP

237+import Generics.SOP.Record

174import GHC.TypeLits

238import GHC.TypeLits

175import Network.IP.Addr

239import Network.IP.Addr

176

240

177−import qualified Data.ByteString.Lazy as Lazy

241+import qualified Data.Aeson as Aeson

242+import qualified Data.ByteString.Lazy as Lazy (ByteString)

178−import qualified Data.ByteString as Strict hiding (pack, unpack)

243+import qualified Data.ByteString.Lazy as Lazy.ByteString

244+import qualified Data.ByteString as Strict (ByteString)

179−import qualified Data.Text.Lazy as Lazy

245+import qualified Data.Text.Lazy as Lazy (Text)

246+import qualified Data.Text as Strict (Text)

180−import qualified Data.Text as Strict

247+import qualified Data.Text as Strict.Text

181import qualified Data.Vector as Vector

248import qualified Data.Vector as Vector

249+import qualified Database.PostgreSQL.LibPQ as LibPQ

182import qualified GHC.Generics as GHC

250import qualified GHC.Generics as GHC

183import qualified PostgreSQL.Binary.Decoding as Decoding

251import qualified PostgreSQL.Binary.Decoding as Decoding

184import qualified PostgreSQL.Binary.Encoding as Encoding

252import qualified PostgreSQL.Binary.Encoding as Encoding

185

253

254+import Squeal.PostgreSQL.Alias

255+import Squeal.PostgreSQL.List

256+import Squeal.PostgreSQL.PG

186import Squeal.PostgreSQL.Schema

257import Squeal.PostgreSQL.Schema

187

258

188-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into

259-- | A `ToParam` constraint gives an encoding of a Haskell `Type` into

@@ -206,19 +277,20 @@ class ToParam (x :: Type) (pg :: PGType) where

206 toParam :: x -> K Encoding.Encoding pg

277 toParam :: x -> K Encoding.Encoding pg

207instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

278instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

208instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

279instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

209−instance ToParam Word16 'PGint2 where toParam = K . Encoding.int2_word16

210instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

280instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

211−instance ToParam Word32 'PGint4 where toParam = K . Encoding.int4_word32

212instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

281instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

213−instance ToParam Word64 'PGint8 where toParam = K . Encoding.int8_word64

282+instance ToParam Oid 'PGoid where toParam = K . Encoding.int4_word32 . getOid

214instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

283instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

215instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

284instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

216instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric

285instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric

286+instance ToParam Money 'PGmoney where toParam = K . Encoding.int8_int64 . cents

217instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

287instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

218instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

288instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

219instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

289instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

220instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict

290instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict

221instance ToParam Lazy.Text 'PGtext where toParam = K . Encoding.text_lazy

291instance ToParam Lazy.Text 'PGtext where toParam = K . Encoding.text_lazy

292+instance ToParam String 'PGtext where

293+ toParam = K . Encoding.text_strict . Strict.Text.pack

222instance ToParam Strict.ByteString 'PGbytea where

294instance ToParam Strict.ByteString 'PGbytea where

223 toParam = K . Encoding.bytea_strict

295 toParam = K . Encoding.bytea_strict

224instance ToParam Lazy.ByteString 'PGbytea where

296instance ToParam Lazy.ByteString 'PGbytea where

@@ -232,17 +304,40 @@ instance ToParam LocalTime 'PGtimestamp where

232instance ToParam UTCTime 'PGtimestamptz where

304instance ToParam UTCTime 'PGtimestamptz where

233 toParam = K . Encoding.timestamptz_int

305 toParam = K . Encoding.timestamptz_int

234instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int

306instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int

235−instance ToParam Value 'PGjson where toParam = K . Encoding.json_ast

307+instance ToParam Aeson.Value 'PGjson where toParam = K . Encoding.json_ast

236−instance ToParam Value 'PGjsonb where toParam = K . Encoding.jsonb_ast

308+instance ToParam Aeson.Value 'PGjsonb where toParam = K . Encoding.jsonb_ast

237−instance (HasOid pg, ToParam x pg)

309+instance Aeson.ToJSON x => ToParam (Json x) 'PGjson where

310+ toParam = K . Encoding.json_bytes

311+ . Lazy.ByteString.toStrict . Aeson.encode . getJson

312+instance Aeson.ToJSON x => ToParam (Jsonb x) 'PGjsonb where

313+ toParam = K . Encoding.jsonb_bytes

314+ . Lazy.ByteString.toStrict . Aeson.encode . getJsonb

315+instance (ToNullityParam x ty, ty ~ nullity pg, OidOf pg)

316+ => ToParam (VarArray [x]) ('PGvararray ty) where

317+ toParam = K

318+ . Encoding.array_foldable

319+ (getOid (oidOf @pg)) (unK . toNullityParam @x @ty)

320+ . getVarArray

321+instance (ToParam x pg, OidOf pg)

322+ => ToParam (VarArray (Vector x)) ('PGvararray ('NotNull pg)) where

323+ toParam = K

324+ . Encoding.array_vector (getOid (oidOf @pg)) (unK . toParam @x @pg)

325+ . getVarArray

326+instance (ToParam x pg, OidOf pg)

238− => ToParam (Vector (Maybe x)) ('PGvararray pg) where

327+ => ToParam (VarArray (Vector (Maybe x))) ('PGvararray ('Null pg)) where

328+ toParam = K

239− toParam = K . Encoding.nullableArray_vector

329+ . Encoding.nullableArray_vector

240− (oid @pg) (unK . toParam @x @pg)

330+ (getOid (oidOf @pg)) (unK . toParam @x @pg)

331+ . getVarArray

332+instance (ToFixArray x dims ty, ty ~ nullity pg, OidOf pg)

333+ => ToParam (FixArray x) ('PGfixarray dims ty) where

334+ toParam = K . Encoding.array (getOid (oidOf @pg))

335+ . unK . unK . toFixArray @x @dims @ty . getFixArray

241instance

336instance

242 ( IsEnumType x

337 ( IsEnumType x

243 , HasDatatypeInfo x

338 , HasDatatypeInfo x

244− , LabelsFrom x ~ labels

339+ , LabelsPG x ~ labels

245− ) => ToParam x ('PGenum labels) where

340+ ) => ToParam (Enumerated x) ('PGenum labels) where

246 toParam =

341 toParam =

247 let

342 let

248 gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String

343 gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String

@@ -253,24 +348,23 @@ instance

253 gshowConstructor constructors (SOP xs)

348 gshowConstructor constructors (SOP xs)

254 in

349 in

255 K . Encoding.text_strict

350 K . Encoding.text_strict

256− . Strict.pack

351+ . Strict.Text.pack

257 . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))

352 . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))

258 . from

353 . from

354+ . getEnumerated

259instance

355instance

260 ( SListI fields

356 ( SListI fields

261− , MapMaybes xs

357+ , IsRecord x xs

262− , IsProductType x (Maybes xs)

358+ , AllZip ToField xs fields

263− , AllZip ToAliasedParam xs fields

264− , FieldNamesFrom x ~ AliasesOf fields

265− , All HasAliasedOid fields

359+ , All OidOfField fields

266− ) => ToParam x ('PGcomposite fields) where

360+ ) => ToParam (Composite x) ('PGcomposite fields) where

267 toParam =

361 toParam =

268 let

362 let

269

363

270− encoders = htrans (Proxy @ToAliasedParam) toAliasedParam

364+ encoders = htrans (Proxy @ToField) toField

271

365

272 composite

366 composite

273− :: All HasAliasedOid row

367+ :: All OidOfField row

274 => NP (K (Maybe Encoding.Encoding)) row

368 => NP (K (Maybe Encoding.Encoding)) row

275 -> K Encoding.Encoding ('PGcomposite row)

369 -> K Encoding.Encoding ('PGcomposite row)

276 composite fields = K $

370 composite fields = K $

@@ -287,53 +381,179 @@ instance

287 int32BE (fromIntegral (lengthSList (Proxy @xs))) <>

381 int32BE (fromIntegral (lengthSList (Proxy @xs))) <>

288 let

382 let

289 each

383 each

290− :: HasAliasedOid field

384+ :: OidOfField field

291 => K (Maybe Encoding.Encoding) field

385 => K (Maybe Encoding.Encoding) field

292 -> Encoding.Encoding

386 -> Encoding.Encoding

293 each (K field :: K (Maybe Encoding.Encoding) field) =

387 each (K field :: K (Maybe Encoding.Encoding) field) =

294− word32BE (aliasedOid @field)

388+ word32BE (getOid (oidOfField @field))

295 <> case field of

389 <> case field of

296 Nothing -> int64BE (-1)

390 Nothing -> int64BE (-1)

297 Just value ->

391 Just value ->

298 int32BE (fromIntegral (builderLength value))

392 int32BE (fromIntegral (builderLength value))

299 <> value

393 <> value

300 in

394 in

301− hcfoldMap (Proxy @HasAliasedOid) each fields

395+ hcfoldMap (Proxy @OidOfField) each fields

302

396

303 in

397 in

304− composite . encoders . unMaybes . unZ . unSOP . from

398+ composite . encoders . toRecord . getComposite

305−

399+

306−class HasAliasedOid (field :: (Symbol, PGType)) where aliasedOid :: Word32

400+-- | The object identifier of a `PGType`.

307−instance HasOid ty => HasAliasedOid (alias ::: ty) where aliasedOid = oid @ty

401+--

308−

402+-- >>> :set -XTypeApplications

309−class ToAliasedParam (x :: Type) (field :: (Symbol, PGType)) where

403+-- >>> oidOf @'PGbool

310− toAliasedParam :: Maybe x -> K (Maybe Encoding.Encoding) field

404+-- Oid 16

311−instance ToParam x ty => ToAliasedParam x (alias ::: ty) where

405+class OidOf (ty :: PGType) where oidOf :: LibPQ.Oid

312− toAliasedParam = \case

406+instance OidOf 'PGbool where oidOf = LibPQ.Oid 16

313− Nothing -> K Nothing

407+instance OidOf ('PGfixarray ns (null 'PGbool)) where oidOf = LibPQ.Oid 1000

314− Just x -> K . Just . unK $ toParam @x @ty x

408+instance OidOf ('PGvararray (null 'PGbool)) where oidOf = LibPQ.Oid 1000

315−

409+instance OidOf 'PGint2 where oidOf = LibPQ.Oid 21

316−-- | A `ToColumnParam` constraint lifts the `ToParam` encoding

410+instance OidOf ('PGfixarray ns (null 'PGint2)) where oidOf = LibPQ.Oid 1005

317−-- of a `Type` to a `NullityType`, encoding `Maybe`s to `Null`s. You should

411+instance OidOf ('PGvararray (null 'PGint2)) where oidOf = LibPQ.Oid 1005

318−-- not define instances of `ToColumnParam`, just use the provided instances.

412+instance OidOf 'PGint4 where oidOf = LibPQ.Oid 23

319−class ToColumnParam (x :: Type) (ty :: NullityType) where

413+instance OidOf ('PGfixarray ns (null 'PGint4)) where oidOf = LibPQ.Oid 1007

320− -- | >>> toColumnParam @Int16 @('NotNull 'PGint2) 0

414+instance OidOf ('PGvararray (null 'PGint4)) where oidOf = LibPQ.Oid 1007

321− -- K (Just "\NUL\NUL")

415+instance OidOf 'PGint8 where oidOf = LibPQ.Oid 20

322− --

416+instance OidOf ('PGfixarray ns (null 'PGint8)) where oidOf = LibPQ.Oid 1016

323− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) (Just 0)

417+instance OidOf ('PGvararray (null 'PGint8)) where oidOf = LibPQ.Oid 1016

324− -- K (Just "\NUL\NUL")

418+instance OidOf 'PGnumeric where oidOf = LibPQ.Oid 1700

325− --

419+instance OidOf ('PGfixarray ns (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231

326− -- >>> toColumnParam @(Maybe Int16) @('Null 'PGint2) Nothing

420+instance OidOf ('PGvararray (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231

327− -- K Nothing

421+instance OidOf 'PGfloat4 where oidOf = LibPQ.Oid 700

328− toColumnParam :: x -> K (Maybe Strict.ByteString) ty

422+instance OidOf ('PGfixarray ns (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021

329−instance ToParam x pg => ToColumnParam x ('NotNull pg) where

423+instance OidOf ('PGvararray (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021

330− toColumnParam = K . Just . Encoding.encodingBytes . unK . toParam @x @pg

424+instance OidOf 'PGfloat8 where oidOf = LibPQ.Oid 701

331−instance ToParam x pg => ToColumnParam (Maybe x) ('Null pg) where

425+instance OidOf ('PGfixarray ns (null 'PGfloat8)) where oidOf = LibPQ.Oid 1022

332− toColumnParam = K . fmap (Encoding.encodingBytes . unK . toParam @x @pg)

426+instance OidOf ('PGvararray (null 'PGfloat8)) where oidOf = LibPQ.Oid 1022

427+instance OidOf 'PGmoney where oidOf = LibPQ.Oid 790

428+instance OidOf ('PGfixarray ns (null 'PGmoney)) where oidOf = LibPQ.Oid 791

429+instance OidOf ('PGvararray (null 'PGmoney)) where oidOf = LibPQ.Oid 791

430+instance OidOf ('PGchar n) where oidOf = LibPQ.Oid 18

431+instance OidOf ('PGfixarray ns (null ('PGchar n))) where oidOf = LibPQ.Oid 1002

432+instance OidOf ('PGvararray (null ('PGchar n))) where oidOf = LibPQ.Oid 1002

433+instance OidOf ('PGvarchar n) where oidOf = LibPQ.Oid 1043

434+instance OidOf ('PGfixarray ns (null ('PGvarchar n))) where oidOf = LibPQ.Oid 1015

435+instance OidOf ('PGvararray (null ('PGvarchar n))) where oidOf = LibPQ.Oid 1015

436+instance OidOf 'PGtext where oidOf = LibPQ.Oid 25

437+instance OidOf ('PGfixarray ns (null 'PGtext)) where oidOf = LibPQ.Oid 1009

438+instance OidOf ('PGvararray (null 'PGtext)) where oidOf = LibPQ.Oid 1009

439+instance OidOf 'PGbytea where oidOf = LibPQ.Oid 17

440+instance OidOf ('PGfixarray ns (null 'PGbytea)) where oidOf = LibPQ.Oid 1001

441+instance OidOf ('PGvararray (null 'PGbytea)) where oidOf = LibPQ.Oid 1001

442+instance OidOf 'PGtimestamp where oidOf = LibPQ.Oid 1114

443+instance OidOf ('PGfixarray ns (null 'PGtimestamp)) where oidOf = LibPQ.Oid 1115

444+instance OidOf ('PGvararray (null 'PGtimestamp)) where oidOf = LibPQ.Oid 1115

445+instance OidOf 'PGtimestamptz where oidOf = LibPQ.Oid 1184

446+instance OidOf ('PGfixarray ns (null 'PGtimestamptz)) where oidOf = LibPQ.Oid 1185

447+instance OidOf ('PGvararray (null 'PGtimestamptz)) where oidOf = LibPQ.Oid 1185

448+instance OidOf 'PGdate where oidOf = LibPQ.Oid 1082

449+instance OidOf ('PGfixarray ns (null 'PGdate)) where oidOf = LibPQ.Oid 1182

450+instance OidOf ('PGvararray (null 'PGdate)) where oidOf = LibPQ.Oid 1182

451+instance OidOf 'PGtime where oidOf = LibPQ.Oid 1083

452+instance OidOf ('PGfixarray ns (null 'PGtime)) where oidOf = LibPQ.Oid 1183

453+instance OidOf ('PGvararray (null 'PGtime)) where oidOf = LibPQ.Oid 1183

454+instance OidOf 'PGtimetz where oidOf = LibPQ.Oid 1266

455+instance OidOf ('PGfixarray ns (null 'PGtimetz)) where oidOf = LibPQ.Oid 1270

456+instance OidOf ('PGvararray (null 'PGtimetz)) where oidOf = LibPQ.Oid 1270

457+instance OidOf 'PGinterval where oidOf = LibPQ.Oid 1186

458+instance OidOf ('PGfixarray ns (null 'PGinterval)) where oidOf = LibPQ.Oid 1187

459+instance OidOf ('PGvararray (null 'PGinterval)) where oidOf = LibPQ.Oid 1187

460+instance OidOf 'PGuuid where oidOf = LibPQ.Oid 2950

461+instance OidOf ('PGfixarray ns (null 'PGuuid)) where oidOf = LibPQ.Oid 2951

462+instance OidOf ('PGvararray (null 'PGuuid)) where oidOf = LibPQ.Oid 2951

463+instance OidOf 'PGinet where oidOf = LibPQ.Oid 869

464+instance OidOf ('PGfixarray ns (null 'PGinet)) where oidOf = LibPQ.Oid 1041

465+instance OidOf ('PGvararray (null 'PGinet)) where oidOf = LibPQ.Oid 1041

466+instance OidOf 'PGjson where oidOf = LibPQ.Oid 114

467+instance OidOf ('PGfixarray ns (null 'PGjson)) where oidOf = LibPQ.Oid 199

468+instance OidOf ('PGvararray (null 'PGjson)) where oidOf = LibPQ.Oid 199

469+instance OidOf 'PGjsonb where oidOf = LibPQ.Oid 3802

470+instance OidOf ('PGfixarray ns (null 'PGjsonb)) where oidOf = LibPQ.Oid 3807

471+instance OidOf ('PGvararray (null 'PGjsonb)) where oidOf = LibPQ.Oid 3807

472+instance OidOf 'PGtsvector where oidOf = LibPQ.Oid 3614

473+instance OidOf ('PGfixarray ns (null 'PGtsvector)) where oidOf = LibPQ.Oid 3643

474+instance OidOf ('PGvararray (null 'PGtsvector)) where oidOf = LibPQ.Oid 3643

475+instance OidOf 'PGtsquery where oidOf = LibPQ.Oid 3615

476+instance OidOf ('PGfixarray ns (null 'PGtsquery)) where oidOf = LibPQ.Oid 3645

477+instance OidOf ('PGvararray (null 'PGtsquery)) where oidOf = LibPQ.Oid 3645

478+instance OidOf 'PGoid where oidOf = LibPQ.Oid 26

479+instance OidOf ('PGfixarray ns (null 'PGoid)) where oidOf = LibPQ.Oid 1028

480+instance OidOf ('PGvararray (null 'PGoid)) where oidOf = LibPQ.Oid 1028

481+instance OidOf ('PGrange 'PGint4) where oidOf = LibPQ.Oid 3904

482+instance OidOf ('PGfixarray ns (null ('PGrange 'PGint4))) where oidOf = LibPQ.Oid 3905

483+instance OidOf ('PGvararray (null ('PGrange 'PGint4))) where oidOf = LibPQ.Oid 3905

484+instance OidOf ('PGrange 'PGint8) where oidOf = LibPQ.Oid 3926

485+instance OidOf ('PGfixarray ns (null ('PGrange 'PGint8))) where oidOf = LibPQ.Oid 3927

486+instance OidOf ('PGvararray (null ('PGrange 'PGint8))) where oidOf = LibPQ.Oid 3927

487+instance OidOf ('PGrange 'PGnumeric) where oidOf = LibPQ.Oid 3906

488+instance OidOf ('PGfixarray ns (null ('PGrange 'PGnumeric))) where oidOf = LibPQ.Oid 3907

489+instance OidOf ('PGvararray (null ('PGrange 'PGnumeric))) where oidOf = LibPQ.Oid 3907

490+instance OidOf ('PGrange 'PGtimestamp) where oidOf = LibPQ.Oid 3908

491+instance OidOf ('PGfixarray ns (null ('PGrange 'PGtimestamp))) where oidOf = LibPQ.Oid 3909

492+instance OidOf ('PGvararray (null ('PGrange 'PGtimestamp))) where oidOf = LibPQ.Oid 3909

493+instance OidOf ('PGrange 'PGtimestamptz) where oidOf = LibPQ.Oid 3910

494+instance OidOf ('PGfixarray ns (null ('PGrange 'PGtimestamptz))) where oidOf = LibPQ.Oid 3911

495+instance OidOf ('PGvararray (null ('PGrange 'PGtimestamptz))) where oidOf = LibPQ.Oid 3911

496+instance OidOf ('PGrange 'PGdate) where oidOf = LibPQ.Oid 3912

497+instance OidOf ('PGfixarray ns (null ('PGrange 'PGdate))) where oidOf = LibPQ.Oid 3913

498+instance OidOf ('PGvararray (null ('PGrange 'PGdate))) where oidOf = LibPQ.Oid 3913

499+instance {-# OVERLAPPABLE #-} OidOf ('PGrange ty) where oidOf = LibPQ.invalidOid

500+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGrange ty))) where oidOf = LibPQ.invalidOid

501+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGrange ty))) where oidOf = LibPQ.invalidOid

502+instance {-# OVERLAPPABLE #-} OidOf ('PGcomposite row) where oidOf = LibPQ.invalidOid

503+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGcomposite row))) where oidOf = LibPQ.invalidOid

504+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGcomposite row))) where oidOf = LibPQ.invalidOid

505+instance {-# OVERLAPPABLE #-} OidOf ('PGenum labels) where oidOf = LibPQ.invalidOid

506+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGenum labels))) where oidOf = LibPQ.invalidOid

507+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGenum labels))) where oidOf = LibPQ.invalidOid

508+

509+class OidOfParam (ty :: NullityType) where oidOfParam :: Oid

510+instance OidOf ty => OidOfParam (null ty) where oidOfParam = oidOf @ty

511+

512+-- | Lifts a `OidOf` constraint to a field.

513+class OidOfField (field :: (Symbol, NullityType)) where

514+ oidOfField :: Oid

515+instance OidOf ty => OidOfField (alias ::: nullity ty) where

516+ oidOfField = oidOf @ty

517+

518+-- | A `ToNullityParam` constraint gives an encoding of a Haskell `Type` into

519+-- into the binary format of a PostgreSQL `NullityType`.

520+class ToNullityParam (x :: Type) (ty :: NullityType) where

521+ toNullityParam :: x -> K (Maybe Encoding.Encoding) ty

522+instance ToParam x pg => ToNullityParam x ('NotNull pg) where

523+ toNullityParam = K . Just . unK . toParam @x @pg

524+instance ToParam x pg => ToNullityParam (Maybe x) ('Null pg) where

525+ toNullityParam = K . fmap (unK . toParam @x @pg)

526+

527+-- | A `ToField` constraint lifts the `ToParam` parser

528+-- to an encoding of a @(Symbol, Type)@ to a @(Symbol, NullityType)@,

529+-- encoding `Null`s to `Maybe`s. You should not define instances for

530+-- `FromField`, just use the provided instances.

531+class ToField (x :: (Symbol, Type)) (field :: (Symbol, NullityType)) where

532+ toField :: P x -> K (Maybe Encoding.Encoding) field

533+instance ToNullityParam x ty => ToField (alias ::: x) (alias ::: ty) where

534+ toField (P x) = K . unK $ toNullityParam @x @ty x

535+

536+-- | A `ToFixArray` constraint gives an encoding of a Haskell `Type`

537+-- into the binary format of a PostgreSQL fixed-length array.

538+-- You should not define instances for

539+-- `ToFixArray`, just use the provided instances.

540+class ToFixArray (x :: Type) (dims :: [Nat]) (array :: NullityType) where

541+ toFixArray :: x -> K (K Encoding.Array dims) array

542+instance ToNullityParam x ty => ToFixArray x '[] ty where

543+ toFixArray = K . K . maybe Encoding.nullArray Encoding.encodingArray . unK

544+ . toNullityParam @x @ty

545+instance

546+ ( IsProductType product xs

547+ , Length xs ~ dim

548+ , All ((~) x) xs

549+ , ToFixArray x dims ty )

550+ => ToFixArray product (dim ': dims) ty where

551+ toFixArray = K . K . Encoding.dimensionArray foldlN

552+ (unK . unK . toFixArray @x @dims @ty) . unZ . unSOP . from

333

553

334-- | A `ToParams` constraint generically sequences the encodings of `Type`s

554-- | A `ToParams` constraint generically sequences the encodings of `Type`s

335-- of the fields of a tuple or record to a row of `ColumnType`s. You should

555-- of the fields of a tuple or record to a row of `ColumnType`s. You should

336−-- not define instances of `ToParams`. Instead define `Generic` instances

556+-- not define instances of `ToParams`. Instead define `SOP.Generic` instances

337-- which in turn provide `ToParams` instances.

557-- which in turn provide `ToParams` instances.

338class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

558class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

339 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]

559 -- | >>> type Params = '[ 'NotNull 'PGbool, 'Null 'PGint2]

@@ -345,61 +565,98 @@ class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

345 -- >>> instance Generic Tuple

565 -- >>> instance Generic Tuple

346 -- >>> toParams @Tuple @Params (Tuple False (Just 0))

566 -- >>> toParams @Tuple @Params (Tuple False (Just 0))

347 -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil

567 -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil

348− toParams :: x -> NP (K (Maybe Strict.ByteString)) tys

568+ toParams :: x -> NP (K (Maybe Encoding.Encoding)) tys

349−instance (SListI tys, IsProductType x xs, AllZip ToColumnParam xs tys)

569+instance (SListI tys, IsProductType x xs, AllZip ToNullityParam xs tys)

350 => ToParams x tys where

570 => ToParams x tys where

351 toParams

571 toParams

352− = htrans (Proxy @ToColumnParam) (toColumnParam . unI)

572+ = htrans (Proxy @ToNullityParam) (toNullityParam . unI)

353 . unZ . unSOP . from

573 . unZ . unSOP . from

354

574

355-- | A `FromValue` constraint gives a parser from the binary format of

575-- | A `FromValue` constraint gives a parser from the binary format of

356-- a PostgreSQL `PGType` into a Haskell `Type`.

576-- a PostgreSQL `PGType` into a Haskell `Type`.

357class FromValue (pg :: PGType) (y :: Type) where

577class FromValue (pg :: PGType) (y :: Type) where

358 -- | >>> newtype Id = Id { getId :: Int16 } deriving Show

578 -- | >>> newtype Id = Id { getId :: Int16 } deriving Show

359− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue

579+ -- >>> instance FromValue 'PGint2 Id where fromValue = Id <$> fromValue @'PGint2

360− fromValue :: proxy pg -> Decoding.Value y

580+ fromValue :: Decoding.Value y

361−instance FromValue 'PGbool Bool where fromValue _ = Decoding.bool

581+instance FromValue 'PGbool Bool where fromValue = Decoding.bool

362−instance FromValue 'PGint2 Int16 where fromValue _ = Decoding.int

582+instance FromValue 'PGint2 Int16 where fromValue = Decoding.int

363−instance FromValue 'PGint4 Int32 where fromValue _ = Decoding.int

583+instance FromValue 'PGint4 Int32 where fromValue = Decoding.int

364−instance FromValue 'PGint8 Int64 where fromValue _ = Decoding.int

584+instance FromValue 'PGint8 Int64 where fromValue = Decoding.int

585+instance FromValue 'PGoid Word32 where fromValue = Decoding.int

365−instance FromValue 'PGfloat4 Float where fromValue _ = Decoding.float4

586+instance FromValue 'PGfloat4 Float where fromValue = Decoding.float4

366−instance FromValue 'PGfloat8 Double where fromValue _ = Decoding.float8

587+instance FromValue 'PGfloat8 Double where fromValue = Decoding.float8

367−instance FromValue 'PGnumeric Scientific where fromValue _ = Decoding.numeric

588+instance FromValue 'PGnumeric Scientific where fromValue = Decoding.numeric

589+instance FromValue 'PGmoney Money where fromValue = Money <$> Decoding.int

368−instance FromValue 'PGuuid UUID where fromValue _ = Decoding.uuid

590+instance FromValue 'PGuuid UUID where fromValue = Decoding.uuid

369−instance FromValue 'PGinet (NetAddr IP) where fromValue _ = Decoding.inet

591+instance FromValue 'PGinet (NetAddr IP) where fromValue = Decoding.inet

370−instance FromValue ('PGchar 1) Char where fromValue _ = Decoding.char

592+instance FromValue ('PGchar 1) Char where fromValue = Decoding.char

371−instance FromValue 'PGtext Strict.Text where fromValue _ = Decoding.text_strict

593+instance FromValue 'PGtext Strict.Text where fromValue = Decoding.text_strict

372−instance FromValue 'PGtext Lazy.Text where fromValue _ = Decoding.text_lazy

594+instance FromValue 'PGtext Lazy.Text where fromValue = Decoding.text_lazy

595+instance FromValue 'PGtext String where

596+ fromValue = Strict.Text.unpack <$> Decoding.text_strict

373instance FromValue 'PGbytea Strict.ByteString where

597instance FromValue 'PGbytea Strict.ByteString where

374− fromValue _ = Decoding.bytea_strict

598+ fromValue = Decoding.bytea_strict

375instance FromValue 'PGbytea Lazy.ByteString where

599instance FromValue 'PGbytea Lazy.ByteString where

376− fromValue _ = Decoding.bytea_lazy

600+ fromValue = Decoding.bytea_lazy

377−instance FromValue 'PGdate Day where fromValue _ = Decoding.date

601+instance FromValue 'PGdate Day where fromValue = Decoding.date

378−instance FromValue 'PGtime TimeOfDay where fromValue _ = Decoding.time_int

602+instance FromValue 'PGtime TimeOfDay where fromValue = Decoding.time_int

379instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where

603instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where

380− fromValue _ = Decoding.timetz_int

604+ fromValue = Decoding.timetz_int

381instance FromValue 'PGtimestamp LocalTime where

605instance FromValue 'PGtimestamp LocalTime where

382− fromValue _ = Decoding.timestamp_int

606+ fromValue = Decoding.timestamp_int

383instance FromValue 'PGtimestamptz UTCTime where

607instance FromValue 'PGtimestamptz UTCTime where

384− fromValue _ = Decoding.timestamptz_int

608+ fromValue = Decoding.timestamptz_int

385instance FromValue 'PGinterval DiffTime where

609instance FromValue 'PGinterval DiffTime where

386− fromValue _ = Decoding.interval_int

610+ fromValue = Decoding.interval_int

387−instance FromValue 'PGjson Value where fromValue _ = Decoding.json_ast

611+instance FromValue 'PGjson Aeson.Value where fromValue = Decoding.json_ast

388−instance FromValue 'PGjsonb Value where fromValue _ = Decoding.jsonb_ast

612+instance FromValue 'PGjsonb Aeson.Value where fromValue = Decoding.jsonb_ast

613+instance Aeson.FromJSON x => FromValue 'PGjson (Json x) where

614+ fromValue = Json <$>

615+ Decoding.json_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)

616+instance Aeson.FromJSON x => FromValue 'PGjsonb (Jsonb x) where

617+ fromValue = Jsonb <$>

618+ Decoding.jsonb_bytes (left Strict.Text.pack . Aeson.eitherDecodeStrict)

619+instance FromValue pg y

389−instance FromValue pg y => FromValue ('PGvararray pg) (Vector (Maybe y)) where

620+ => FromValue ('PGvararray ('NotNull pg)) (VarArray (Vector y)) where

390− fromValue _ = Decoding.array

621+ fromValue =

622+ let

623+ rep n x = VarArray <$> Vector.replicateM n x

624+ in

391− (Decoding.dimensionArray Vector.replicateM

625+ Decoding.array $ Decoding.dimensionArray rep

392− (Decoding.nullableValueArray (fromValue (Proxy @pg))))

626+ (fromFixArray @'[] @('NotNull pg))

627+instance FromValue pg y

628+ => FromValue ('PGvararray ('Null pg)) (VarArray (Vector (Maybe y))) where

629+ fromValue =

630+ let

631+ rep n x = VarArray <$> Vector.replicateM n x

632+ in

633+ Decoding.array $ Decoding.dimensionArray rep

634+ (fromFixArray @'[] @('Null pg))

635+instance FromValue pg y

636+ => FromValue ('PGvararray ('NotNull pg)) (VarArray [y]) where

637+ fromValue =

638+ let

639+ rep n x = VarArray <$> replicateM n x

640+ in

641+ Decoding.array $ Decoding.dimensionArray rep

642+ (fromFixArray @'[] @('NotNull pg))

643+instance FromValue pg y

644+ => FromValue ('PGvararray ('Null pg)) (VarArray [Maybe y]) where

645+ fromValue =

646+ let

647+ rep n x = VarArray <$> replicateM n x

648+ in

649+ Decoding.array $ Decoding.dimensionArray rep

650+ (fromFixArray @'[] @('Null pg))

651+instance FromFixArray dims ty y

393−instance FromValue pg y => FromValue ('PGfixarray n pg) (Vector (Maybe y)) where

652+ => FromValue ('PGfixarray dims ty) (FixArray y) where

394− fromValue _ = Decoding.array

653+ fromValue = FixArray <$> Decoding.array (fromFixArray @dims @ty @y)

395− (Decoding.dimensionArray Vector.replicateM

396− (Decoding.nullableValueArray (fromValue (Proxy @pg))))

397instance

654instance

398 ( IsEnumType y

655 ( IsEnumType y

399 , HasDatatypeInfo y

656 , HasDatatypeInfo y

400− , LabelsFrom y ~ labels

657+ , LabelsPG y ~ labels

401− ) => FromValue ('PGenum labels) y where

658+ ) => FromValue ('PGenum labels) (Enumerated y) where

402− fromValue _ =

659+ fromValue =

403 let

660 let

404 greadConstructor

661 greadConstructor

405 :: All ((~) '[]) xss

662 :: All ((~) '[]) xss

@@ -412,29 +669,16 @@ instance

412 then Just (SOP (Z Nil))

669 then Just (SOP (Z Nil))

413 else SOP . S . unSOP <$> greadConstructor constructors name

670 else SOP . S . unSOP <$> greadConstructor constructors name

414 in

671 in

672+ fmap Enumerated

415− Decoding.enum

673+ . Decoding.enum

416 $ fmap to

674 $ fmap to

417 . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))

675 . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))

418− . Strict.unpack

676+ . Strict.Text.unpack

419−

420instance

677instance

421− ( SListI fields

678+ ( FromRow fields y

422− , MapMaybes ys

423− , IsProductType y (Maybes ys)

424− , AllZip FromAliasedValue fields ys

425− , FieldNamesFrom y ~ AliasesOf fields

426− ) => FromValue ('PGcomposite fields) y where

679+ ) => FromValue ('PGcomposite fields) (Composite y) where

427 fromValue =

680 fromValue =

428 let

681 let

429− decoders

430− :: forall pgs zs proxy

431− . AllZip FromAliasedValue pgs zs

432− => proxy ('PGcomposite pgs)

433− -> NP Decoding.Value zs

434− decoders _ = htrans (Proxy @FromAliasedValue) fromAliasedValue

435− (hpure Proxy :: NP Proxy pgs)

436−

437− composite fields = do

438 -- <number of fields: 4 bytes>

682 -- <number of fields: 4 bytes>

439 -- [for each field]

683 -- [for each field]

440 -- <OID of field's type: sizeof(Oid) bytes>

684 -- <OID of field's type: sizeof(Oid) bytes>

@@ -445,80 +689,133 @@ instance

445 -- <value: <length> bytes>

689 -- <value: <length> bytes>

446 -- [end if]

690 -- [end if]

447 -- [end for]

691 -- [end for]

692+ composite = Decoding.valueParser $ do

448 unitOfSize 4

693 unitOfSize 4

449− let

694+ hsequence' $ hpure $ Comp $ do

450− each field = do

451− unitOfSize 4

695+ unitOfSize 4

452− len <- sized 4 Decoding.int

696+ len <- sized 4 Decoding.int

697+ if len == -1

453− if len == -1 then return Nothing else Just <$> sized len field

698+ then return (K Nothing)

454− htraverse' each fields

699+ else K . Just <$> bytesOfSize len

455−

700+ in

456− in fmap (to . SOP . Z . maybes) . composite . decoders

701+ fmap Composite (Decoding.fn (fromRow @fields <=< composite))

457−

458−class FromAliasedValue (pg :: (Symbol,PGType)) (y :: Type) where

459− fromAliasedValue :: proxy pg -> Decoding.Value y

460−instance FromValue pg y => FromAliasedValue (alias ::: pg) y where

461− fromAliasedValue _ = fromValue (Proxy @pg)

462

702

463−-- | A `FromColumnValue` constraint lifts the `FromValue` parser

703+-- | A `FromField` constraint lifts the `FromValue` parser

464-- to a decoding of a @(Symbol, NullityType)@ to a `Type`,

704-- to a decoding of a @(Symbol, NullityType)@ to a `Type`,

465-- decoding `Null`s to `Maybe`s. You should not define instances for

705-- decoding `Null`s to `Maybe`s. You should not define instances for

466−-- `FromColumnValue`, just use the provided instances.

706+-- `FromField`, just use the provided instances.

467−class FromColumnValue (colty :: (Symbol,NullityType)) (y :: Type) where

707+class FromField (pg :: (Symbol, NullityType)) (y :: (Symbol, Type)) where

468− -- | >>> :set -XTypeOperators -XOverloadedStrings

708+ fromField

469− -- >>> newtype Id = Id { getId :: Int16 } deriving Show

470− -- >>> instance FromValue 'PGint2 Id where fromValue = fmap Id . fromValue

471− -- >>> fromColumnValue @("col" ::: 'NotNull 'PGint2) @Id (K (Just "\NUL\SOH"))

472− -- Id {getId = 1}

473− --

474− -- >>> fromColumnValue @("col" ::: 'Null 'PGint2) @(Maybe Id) (K (Just "\NUL\SOH"))

475− -- Just (Id {getId = 1})

476− fromColumnValue :: K (Maybe Strict.ByteString) colty -> y

709+ :: K (Maybe Strict.ByteString) pg

710+ -> (Either Strict.Text :.: P) y

477instance FromValue pg y

711instance FromValue pg y

478− => FromColumnValue (column ::: ('NotNull pg)) y where

712+ => FromField (column ::: ('NotNull pg)) (column ::: y) where

479− fromColumnValue = \case

713+ fromField = Comp . \case

480− K Nothing -> error "fromColumnValue: saw NULL when expecting NOT NULL"

714+ K Nothing -> Left "fromField: saw NULL when expecting NOT NULL"

481− K (Just bs) ->

715+ K (Just bytestring) -> P <$>

482− let

483− errOrValue =

484− Decoding.valueParser (fromValue @pg @y Proxy) bs

716+ Decoding.valueParser (fromValue @pg) bytestring

485− err str = error $ "fromColumnValue: " ++ Strict.unpack str

486− in

487− either err id errOrValue

488instance FromValue pg y

717instance FromValue pg y

489− => FromColumnValue (column ::: ('Null pg)) (Maybe y) where

718+ => FromField (column ::: 'Null pg) (column ::: Maybe y) where

490− fromColumnValue (K nullOrBytes)

719+ fromField = Comp . \case

491− = either err id

720+ K Nothing -> Right $ P Nothing

492− . Decoding.valueParser (fromValue @pg @y Proxy)

721+ K (Just bytestring) -> P . Just <$>

493− <$> nullOrBytes

722+ Decoding.valueParser (fromValue @pg) bytestring

494− where

723+

495− err str = error $ "fromColumnValue: " ++ Strict.unpack str

724+-- | A `FromFixArray` constraint gives a decoding to a Haskell `Type`

725+-- from the binary format of a PostgreSQL fixed-length array.

726+-- You should not define instances for

727+-- `FromFixArray`, just use the provided instances.

728+class FromFixArray (dims :: [Nat]) (ty :: NullityType) (y :: Type) where

729+ fromFixArray :: Decoding.Array y

730+instance FromValue pg y => FromFixArray '[] ('NotNull pg) y where

731+ fromFixArray = Decoding.valueArray (fromValue @pg @y)

732+instance FromValue pg y => FromFixArray '[] ('Null pg) (Maybe y) where

733+ fromFixArray = Decoding.nullableValueArray (fromValue @pg @y)

734+instance

735+ ( IsProductType product ys

736+ , Length ys ~ dim

737+ , All ((~) y) ys

738+ , FromFixArray dims ty y )

739+ => FromFixArray (dim ': dims) ty product where

740+ fromFixArray =

741+ let

742+ rep _ = fmap (to . SOP . Z) . replicateMN

743+ in

744+ Decoding.dimensionArray rep (fromFixArray @dims @ty @y)

496

745

497-- | A `FromRow` constraint generically sequences the parsings of the columns

746-- | A `FromRow` constraint generically sequences the parsings of the columns

498−-- of a `RelationType` into the fields of a record `Type` provided they have

747+-- of a `RowType` into the fields of a record `Type` provided they have

499-- the same field names. You should not define instances of `FromRow`.

748-- the same field names. You should not define instances of `FromRow`.

500−-- Instead define `Generic` and `HasDatatypeInfo` instances which in turn

749+-- Instead define `SOP.Generic` and `SOP.HasDatatypeInfo` instances which in turn

501-- provide `FromRow` instances.

750-- provide `FromRow` instances.

502−class SListI results => FromRow (results :: RelationType) y where

751+class SListI result => FromRow (result :: RowType) y where

503 -- | >>> :set -XOverloadedStrings

752 -- | >>> :set -XOverloadedStrings

504 -- >>> import Data.Text

753 -- >>> import Data.Text

505 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show

754 -- >>> newtype UserId = UserId { getUserId :: Int16 } deriving Show

506− -- >>> instance FromValue 'PGint2 UserId where fromValue = fmap UserId . fromValue

755+ -- >>> instance FromValue 'PGint2 UserId where fromValue = UserId <$> fromValue @'PGint2

507 -- >>> data UserRow = UserRow { userId :: UserId, userName :: Maybe Text } deriving (Show, GHC.Generic)

756 -- >>> data UserRow = UserRow { userId :: UserId, userName :: Maybe Text } deriving (Show, GHC.Generic)

508 -- >>> instance Generic UserRow

757 -- >>> instance Generic UserRow

509 -- >>> instance HasDatatypeInfo UserRow

758 -- >>> instance HasDatatypeInfo UserRow

510 -- >>> type User = '["userId" ::: 'NotNull 'PGint2, "userName" ::: 'Null 'PGtext]

759 -- >>> type User = '["userId" ::: 'NotNull 'PGint2, "userName" ::: 'Null 'PGtext]

511 -- >>> fromRow @User @UserRow (K (Just "\NUL\SOH") :* K (Just "bloodninja") :* Nil)

760 -- >>> fromRow @User @UserRow (K (Just "\NUL\SOH") :* K (Just "bloodninja") :* Nil)

512− -- UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"}

761+ -- Right (UserRow {userId = UserId {getUserId = 1}, userName = Just "bloodninja"})

513− fromRow :: NP (K (Maybe Strict.ByteString)) results -> y

762+ fromRow :: NP (K (Maybe Strict.ByteString)) result -> Either Strict.Text y

514instance

763instance

515− ( SListI results

764+ ( SListI result

516− , IsProductType y ys

765+ , IsRecord y ys

517− , AllZip FromColumnValue results ys

766+ , AllZip FromField result ys

518− , FieldNamesFrom y ~ AliasesOf results

519− ) => FromRow results y where

767+ ) => FromRow result y where

520 fromRow

768 fromRow

521− = to . SOP . Z . htrans (Proxy @FromColumnValue) (I . fromColumnValue)

769+ = fmap fromRecord

770+ . hsequence'

771+ . htrans (Proxy @FromField) fromField

772+------------------------------------------------------

773+-- P records

774+------------------------------------------------------

775+-- instance (FromField (col ::: pg) (col ::: hask))

776+-- => FromRow '[col ::: pg] (P (col ::: hask)) where

777+-- fromRow (pg :* Nil) = (unComp . fromField) pg

778+-- instance

779+-- ( row ~ Join row1 row2

780+-- , FromRow row1 hask1

781+-- , FromRow row2 hask2

782+-- , SListI row

783+-- ) => FromRow row (hask1, hask2) where

784+-- fromRow row = case disjoin @row1 @row2 row of

785+-- (row1, row2) -> (,) <$> fromRow row1 <*> fromRow row2

786+-- instance

787+-- ( row ~ Join row1 row23

788+-- , FromRow row1 hask1

789+-- , FromRow row23 (hask2, hask3)

790+-- , SListI row

791+-- ) => FromRow row (hask1, hask2, hask3) where

792+-- fromRow row = case disjoin @row1 @row23 row of

793+-- (row1, row23) -> do

794+-- hask1 <- fromRow row1

795+-- (hask2, hask3) <- fromRow row23

796+-- return (hask1, hask2, hask3)

797+-- instance

798+-- ( row ~ Join row1 row234

799+-- , FromRow row1 hask1

800+-- , FromRow row234 (hask2, hask3, hask4)

801+-- , SListI row

802+-- ) => FromRow row (hask1, hask2, hask3, hask4) where

803+-- fromRow row = case disjoin @row1 @row234 row of

804+-- (row1, row234) -> do

805+-- hask1 <- fromRow row1

806+-- (hask2, hask3, hask4) <- fromRow row234

807+-- return (hask1, hask2, hask3, hask4)

808+-- instance

809+-- ( row ~ Join row1 row2345

810+-- , FromRow row1 hask1

811+-- , FromRow row2345 (hask2, hask3, hask4, hask5)

812+-- , SListI row

813+-- ) => FromRow row (hask1, hask2, hask3, hask4, hask5) where

814+-- fromRow row = case disjoin @row1 @row2345 row of

815+-- (row1, row2345) -> do

816+-- hask1 <- fromRow row1

817+-- (hask2, hask3, hask4, hask5) <- fromRow row2345

818+-- return (hask1, hask2, hask3, hask4, hask5)

522

819

523-- | `Only` is a 1-tuple type, useful for encoding a single parameter with

820-- | `Only` is a 1-tuple type, useful for encoding a single parameter with

524-- `toParams` or decoding a single value with `fromRow`.

821-- `toParams` or decoding a single value with `fromRow`.

@@ -528,8 +825,24 @@ instance

528-- K (Just "foo") :* Nil

825-- K (Just "foo") :* Nil

529--

826--

530-- >>> fromRow @'["fromOnly" ::: 'Null 'PGtext] @(Only (Maybe Text)) (K (Just "bar") :* Nil)

827-- >>> fromRow @'["fromOnly" ::: 'Null 'PGtext] @(Only (Maybe Text)) (K (Just "bar") :* Nil)

531−-- Only {fromOnly = Just "bar"}

828+-- Right (Only {fromOnly = Just "bar"})

532newtype Only x = Only { fromOnly :: x }

829newtype Only x = Only { fromOnly :: x }

533 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)

830 deriving (Functor,Foldable,Traversable,Eq,Ord,Read,Show,GHC.Generic)

534instance Generic (Only x)

831instance Generic (Only x)

535instance HasDatatypeInfo (Only x)

832instance HasDatatypeInfo (Only x)

833+

834+foldlN

835+ :: All ((~) x) xs

836+ => (z -> x -> z) -> z -> NP I xs -> z

837+foldlN f z = \case

838+ Nil -> z

839+ I x :* xs -> let z' = f z x in seq z' $ foldlN f z' xs

840+

841+replicateMN

842+ :: forall x xs m. (All ((~) x) xs, Monad m, SListI xs)

843+ => m x -> m (NP I xs)

844+replicateMN mx = hsequence' $

845+ hcpure (Proxy :: Proxy ((~) x)) (Comp (I <$> mx))

846+

847+getOid :: LibPQ.Oid -> Word32

848+getOid (LibPQ.Oid (CUInt oid)) = oid

squeal-postgresql/src/Squeal/PostgreSQL/Definition.hs+23−893

@@ -11,13 +11,15 @@ Squeal data definition language.

11{-# LANGUAGE

12 AllowAmbiguousTypes

13 , ConstraintKinds

14+ , DeriveAnyClass

14 , DeriveGeneric

15 , DeriveGeneric

16+ , DerivingStrategies

15 , FlexibleContexts

17 , FlexibleContexts

16 , FlexibleInstances

18 , FlexibleInstances

17 , GADTs

19 , GADTs

18− , GeneralizedNewtypeDeriving

19 , LambdaCase

20 , LambdaCase

20 , MultiParamTypeClasses

21 , MultiParamTypeClasses

22+ , OverloadedLabels

21 , OverloadedStrings

23 , OverloadedStrings

22 , RankNTypes

24 , RankNTypes

23 , ScopedTypeVariables

25 , ScopedTypeVariables

@@ -25,928 +27,56 @@ Squeal data definition language.

25 , TypeInType

27 , TypeInType

26 , TypeOperators

28 , TypeOperators

27 , UndecidableSuperClasses

29 , UndecidableSuperClasses

30+ , UndecidableInstances

28#-}

31#-}

30module Squeal.PostgreSQL.Definition

33module Squeal.PostgreSQL.Definition

31 ( -- * Definition

34 ( -- * Definition

32− Definition (UnsafeDefinition, renderDefinition)

35+ Definition (..)

33 , (>>>)

36 , (>>>)

34− -- * Tables

37+ , manipDefinition

35− -- ** Create

36− , createTable

37− , createTableIfNotExists

38− , TableConstraintExpression (..)

39− , check

40− , unique

41− , primaryKey

42− , foreignKey

43− , ForeignKeyed

44− , OnDeleteClause (OnDeleteNoAction, OnDeleteRestrict, OnDeleteCascade)

45− , renderOnDeleteClause

46− , OnUpdateClause (OnUpdateNoAction, OnUpdateRestrict, OnUpdateCascade)

47− , renderOnUpdateClause

48− -- ** Drop

49− , dropTable

50− -- ** Alter

51− , alterTable

52− , alterTableRename

53− , AlterTable (UnsafeAlterTable, renderAlterTable)

54− , addConstraint

55− , dropConstraint

56− , AddColumn (addColumn)

57− , dropColumn

58− , renameColumn

59− , alterColumn

60− , AlterColumn (UnsafeAlterColumn, renderAlterColumn)

61− , setDefault

62− , dropDefault

63− , setNotNull

64− , dropNotNull

65− , alterType

66− -- * Views

67− , createView

68− , dropView

69− -- * Types

70− , createTypeEnum

71− , createTypeEnumFrom

72− , createTypeComposite

73− , createTypeCompositeFrom

74− , dropType

75− -- * Columns

76− , ColumnTypeExpression (..)

77− , nullable

78− , notNullable

79− , default_

80− , serial2

81− , smallserial

82− , serial4

83− , serial

84− , serial8

85− , bigserial

86 ) where

38 ) where

88import Control.Category

40import Control.Category

89import Control.DeepSeq

41import Control.DeepSeq

90import Data.ByteString

42import Data.ByteString

91import Data.Monoid

43import Data.Monoid

92−import GHC.TypeLits

93import Prelude hiding ((.), id)

44import Prelude hiding ((.), id)

95−import qualified Generics.SOP as SOP

96import qualified GHC.Generics as GHC

46import qualified GHC.Generics as GHC

98−import Squeal.PostgreSQL.Expression

48+import Squeal.PostgreSQL.Manipulation

99−import Squeal.PostgreSQL.Query

100import Squeal.PostgreSQL.Render

49import Squeal.PostgreSQL.Render

101import Squeal.PostgreSQL.Schema

50import Squeal.PostgreSQL.Schema

102

52+-- $setup

53+-- >>> import Squeal.PostgreSQL

54+

103{-----------------------------------------

55{-----------------------------------------

104statements

56statements

105-----------------------------------------}

57-----------------------------------------}

106

107−-- | A `Definition` is a statement that changes the schema of the

59+-- | A `Definition` is a statement that changes the schemas of the

108-- database, like a `createTable`, `dropTable`, or `alterTable` command.

60-- database, like a `createTable`, `dropTable`, or `alterTable` command.

109-- `Definition`s may be composed using the `>>>` operator.

61-- `Definition`s may be composed using the `>>>` operator.

110newtype Definition

62newtype Definition

111− (schema0 :: SchemaType)

63+ (schemas0 :: SchemasType)

112− (schema1 :: SchemaType)

64+ (schemas1 :: SchemasType)

113 = UnsafeDefinition { renderDefinition :: ByteString }

65 = UnsafeDefinition { renderDefinition :: ByteString }

114 deriving (GHC.Generic,Show,Eq,Ord,NFData)

66 deriving (GHC.Generic,Show,Eq,Ord,NFData)

115

116−instance RenderSQL (Definition schema0 schema1) where

68+instance RenderSQL (Definition schemas0 schemas1) where

117 renderSQL = renderDefinition

69 renderSQL = renderDefinition

118

119instance Category Definition where

71instance Category Definition where

120 id = UnsafeDefinition ";"

72 id = UnsafeDefinition ";"

121 ddl1 . ddl0 = UnsafeDefinition $

73 ddl1 . ddl0 = UnsafeDefinition $

122− renderDefinition ddl0 <> "\n" <> renderDefinition ddl1

74+ renderSQL ddl0 <> "\n" <> renderSQL ddl1

123−

75+

124−{-----------------------------------------

76+-- | A `Manipulation` without input or output can be run as a statement

125−CREATE statements

77+-- along with other `Definition`s, by embedding it using `manipDefinition`.

126−-----------------------------------------}

78+manipDefinition

127−

79+ :: Manipulation '[] schemas '[] '[]

128−{- | `createTable` adds a table to the schema.

80+ -- ^ no input or output

129−

81+ -> Definition schemas schemas

130−>>> :set -XOverloadedLabels

82+manipDefinition = UnsafeDefinition . (<> ";") . renderSQL

131−>>> :{

132−printSQL $

133− createTable #tab ((int & nullable) `As` #a :* (real & nullable) `As` #b :* Nil) Nil

134−:}

135−CREATE TABLE "tab" ("a" int NULL, "b" real NULL);

136−-}

137−createTable

138− :: ( KnownSymbol table

139− , columns ~ (col ': cols)

140− , SOP.SListI columns

141− , SOP.SListI constraints

142− , schema1 ~ Create table ('Table (constraints :=> columns)) schema0 )

143− => Alias table -- ^ the name of the table to add

144− -> NP (Aliased (ColumnTypeExpression schema0)) columns

145− -- ^ the names and datatype of each column

146− -> NP (Aliased (TableConstraintExpression schema1 table)) constraints

147− -- ^ constraints that must hold for the table

148− -> Definition schema0 schema1

149−createTable tab columns constraints = UnsafeDefinition $

150− "CREATE TABLE" <+> renderCreation tab columns constraints

151−

152−{-| `createTableIfNotExists` creates a table if it doesn't exist, but does not add it to the schema.

153−Instead, the schema already has the table so if the table did not yet exist, the schema was wrong.

154−`createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in

155−the `Category` of `Definition`s.

156−

157−>>> :set -XOverloadedLabels -XTypeApplications

158−>>> type Table = '[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGfloat4]

159−>>> type Schema = '["tab" ::: 'Table Table]

160−>>> :{

161−let

162− setup :: Definition Schema Schema

163− setup = createTableIfNotExists #tab ((int & nullable) `As` #a :* (real & nullable) `As` #b :* Nil) Nil

164−in printSQL setup

165−:}

166−CREATE TABLE IF NOT EXISTS "tab" ("a" int NULL, "b" real NULL);

167−-}

168−createTableIfNotExists

169− :: ( Has table schema ('Table (constraints :=> columns))

170− , SOP.SListI columns

171− , SOP.SListI constraints )

172− => Alias table -- ^ the name of the table to add

173− -> NP (Aliased (ColumnTypeExpression schema)) columns

174− -- ^ the names and datatype of each column

175− -> NP (Aliased (TableConstraintExpression schema table)) constraints

176− -- ^ constraints that must hold for the table

177− -> Definition schema schema

178−createTableIfNotExists tab columns constraints = UnsafeDefinition $

179− "CREATE TABLE IF NOT EXISTS"

180− <+> renderCreation tab columns constraints

181−

182−-- helper function for `createTable` and `createTableIfNotExists`

183−renderCreation

184− :: ( KnownSymbol table

185− , SOP.SListI columns

186− , SOP.SListI constraints )

187− => Alias table -- ^ the name of the table to add

188− -> NP (Aliased (ColumnTypeExpression schema0)) columns

189− -- ^ the names and datatype of each column

190− -> NP (Aliased (TableConstraintExpression schema1 table)) constraints

191− -- ^ constraints that must hold for the table

192− -> ByteString

193−renderCreation tab columns constraints = renderAlias tab

194− <+> parenthesized

195− ( renderCommaSeparated renderColumnDef columns

196− <> ( case constraints of

197− Nil -> ""

198− _ -> ", " <>

199− renderCommaSeparated renderConstraint constraints ) )

200− <> ";"

201− where

202− renderColumnDef :: Aliased (ColumnTypeExpression schema) x -> ByteString

203− renderColumnDef (ty `As` column) =

204− renderAlias column <+> renderColumnTypeExpression ty

205− renderConstraint

206− :: Aliased (TableConstraintExpression schema columns) constraint

207− -> ByteString

208− renderConstraint (constraint `As` alias) =

209− "CONSTRAINT" <+> renderAlias alias <+> renderTableConstraintExpression constraint

210−

211−-- | Data types are a way to limit the kind of data that can be stored in a

212−-- table. For many applications, however, the constraint they provide is

213−-- too coarse. For example, a column containing a product price should

214−-- probably only accept positive values. But there is no standard data type

215−-- that accepts only positive numbers. Another issue is that you might want

216−-- to constrain column data with respect to other columns or rows.

217−-- For example, in a table containing product information,

218−-- there should be only one row for each product number.

219−-- `TableConstraint`s give you as much control over the data in your tables

220−-- as you wish. If a user attempts to store data in a column that would

221−-- violate a constraint, an error is raised. This applies

222−-- even if the value came from the default value definition.

223−newtype TableConstraintExpression

224− (schema :: SchemaType)

225− (table :: Symbol)

226− (tableConstraint :: TableConstraint)

227− = UnsafeTableConstraintExpression

228− { renderTableConstraintExpression :: ByteString }

229− deriving (GHC.Generic,Show,Eq,Ord,NFData)

230−

231−{-| A `check` constraint is the most generic `TableConstraint` type.

232−It allows you to specify that the value in a certain column must satisfy

233−a Boolean (truth-value) expression.

234−

235−>>> :{

236−type Schema = '[

237− "tab" ::: 'Table ('[ "inequality" ::: 'Check '["a","b"]] :=> '[

238− "a" ::: 'NoDef :=> 'NotNull 'PGint4,

239− "b" ::: 'NoDef :=> 'NotNull 'PGint4

240− ])]

241−:}

242−

243−>>> :{

244−let

245− definition :: Definition '[] Schema

246− definition = createTable #tab

247− ( (int & notNullable) `As` #a :*

248− (int & notNullable) `As` #b :* Nil )

249− ( check (#a :* #b :* Nil) (#a .> #b) `As` #inequality :* Nil )

250−:}

251−

252−>>> printSQL definition

253−CREATE TABLE "tab" ("a" int NOT NULL, "b" int NOT NULL, CONSTRAINT "inequality" CHECK (("a" > "b")));

254−-}

255−check

256− :: ( Has alias schema ('Table table)

257− , HasAll aliases (TableToRelation table) subcolumns )

258− => NP Alias aliases

259− -- ^ specify the subcolumns which are getting checked

260− -> (forall tab. Condition schema '[tab ::: subcolumns] 'Ungrouped '[])

261− -- ^ a closed `Condition` on those subcolumns

262− -> TableConstraintExpression schema alias ('Check aliases)

263−check _cols condition = UnsafeTableConstraintExpression $

264− "CHECK" <+> parenthesized (renderExpression condition)

265−

266−{-| A `unique` constraint ensure that the data contained in a column,

267−or a group of columns, is unique among all the rows in the table.

268−

269−>>> :{

270−type Schema = '[

271− "tab" ::: 'Table( '[ "uq_a_b" ::: 'Unique '["a","b"]] :=> '[

272− "a" ::: 'NoDef :=> 'Null 'PGint4,

273− "b" ::: 'NoDef :=> 'Null 'PGint4

274− ])]

275−:}

276−

277−>>> :{

278−let

279− definition :: Definition '[] Schema

280− definition = createTable #tab

281− ( (int & nullable) `As` #a :*

282− (int & nullable) `As` #b :* Nil )

283− ( unique (#a :* #b :* Nil) `As` #uq_a_b :* Nil )

284−:}

285−

286−>>> printSQL definition

287−CREATE TABLE "tab" ("a" int NULL, "b" int NULL, CONSTRAINT "uq_a_b" UNIQUE ("a", "b"));

288−-}

289−unique

290− :: ( Has alias schema ('Table table)

291− , HasAll aliases (TableToRelation table) subcolumns )

292− => NP Alias aliases

293− -- ^ specify subcolumns which together are unique for each row

294− -> TableConstraintExpression schema alias ('Unique aliases)

295−unique columns = UnsafeTableConstraintExpression $

296− "UNIQUE" <+> parenthesized (commaSeparated (renderAliases columns))

297−

298−{-| A `primaryKey` constraint indicates that a column, or group of columns,

299−can be used as a unique identifier for rows in the table.

300−This requires that the values be both unique and not null.

301−

302−>>> :{

303−type Schema = '[

304− "tab" ::: 'Table ('[ "pk_id" ::: 'PrimaryKey '["id"]] :=> '[

305− "id" ::: 'Def :=> 'NotNull 'PGint4,

306− "name" ::: 'NoDef :=> 'NotNull 'PGtext

307− ])]

308−:}

309−

310−>>> :{

311−let

312− definition :: Definition '[] Schema

313− definition = createTable #tab

314− ( serial `As` #id :*

315− (text & notNullable) `As` #name :* Nil )

316− ( primaryKey #id `As` #pk_id :* Nil )

317−:}

318−

319−>>> printSQL definition

320−CREATE TABLE "tab" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_id" PRIMARY KEY ("id"));

321−-}

322−primaryKey

323− :: ( Has alias schema ('Table table)

324− , HasAll aliases (TableToColumns table) subcolumns

325− , AllNotNull subcolumns )

326− => NP Alias aliases

327− -- ^ specify the subcolumns which together form a primary key.

328− -> TableConstraintExpression schema alias ('PrimaryKey aliases)

329−primaryKey columns = UnsafeTableConstraintExpression $

330− "PRIMARY KEY" <+> parenthesized (commaSeparated (renderAliases columns))

331−

332−{-| A `foreignKey` specifies that the values in a column

333−(or a group of columns) must match the values appearing in some row of

334−another table. We say this maintains the referential integrity

335−between two related tables.

336−

337−>>> :{

338−type Schema =

339− '[ "users" ::: 'Table (

340− '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

341− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

342− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

343− ])

344− , "emails" ::: 'Table (

345− '[ "pk_emails" ::: 'PrimaryKey '["id"]

346− , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

347− ] :=>

348− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

349− , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

350− , "email" ::: 'NoDef :=> 'Null 'PGtext

351− ])

352− ]

353−:}

354−

355−>>> :{

356−let

357− setup :: Definition '[] Schema

358− setup =

359− createTable #users

360− ( serial `As` #id :*

361− (text & notNullable) `As` #name :* Nil )

362− ( primaryKey #id `As` #pk_users :* Nil ) >>>

363− createTable #emails

364− ( serial `As` #id :*

365− (int & notNullable) `As` #user_id :*

366− (text & nullable) `As` #email :* Nil )

367− ( primaryKey #id `As` #pk_emails :*

368− foreignKey #user_id #users #id

369− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

370−in printSQL setup

371−:}

372−CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));

373−CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

374−

375−A `foreignKey` can even be a table self-reference.

376−

377−>>> :{

378−type Schema =

379− '[ "employees" ::: 'Table (

380− '[ "employees_pk" ::: 'PrimaryKey '["id"]

381− , "employees_employer_fk" ::: 'ForeignKey '["employer_id"] "employees" '["id"]

382− ] :=>

383− '[ "id" ::: 'Def :=> 'NotNull 'PGint4

384− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

385− , "employer_id" ::: 'NoDef :=> 'Null 'PGint4

386− ])

387− ]

388−:}

389−

390−>>> :{

391−let

392− setup :: Definition '[] Schema

393− setup =

394− createTable #employees

395− ( serial `As` #id :*

396− (text & notNullable) `As` #name :*

397− (integer & nullable) `As` #employer_id :* Nil )

398− ( primaryKey #id `As` #employees_pk :*

399− foreignKey #employer_id #employees #id

400− OnDeleteCascade OnUpdateCascade `As` #employees_employer_fk :* Nil )

401−in printSQL setup

402−:}

403−CREATE TABLE "employees" ("id" serial, "name" text NOT NULL, "employer_id" integer NULL, CONSTRAINT "employees_pk" PRIMARY KEY ("id"), CONSTRAINT "employees_employer_fk" FOREIGN KEY ("employer_id") REFERENCES "employees" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

404−-}

405−foreignKey

406− :: (ForeignKeyed schema child parent

407− table reftable

408− columns refcolumns

409− constraints cols

410− reftys tys )

411− => NP Alias columns

412− -- ^ column or columns in the table

413− -> Alias parent

414− -- ^ reference table

415− -> NP Alias refcolumns

416− -- ^ reference column or columns in the reference table

417− -> OnDeleteClause

418− -- ^ what to do when reference is deleted

419− -> OnUpdateClause

420− -- ^ what to do when reference is updated

421− -> TableConstraintExpression schema child

422− ('ForeignKey columns parent refcolumns)

423−foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $

424− "FOREIGN KEY" <+> parenthesized (commaSeparated (renderAliases keys))

425− <+> "REFERENCES" <+> renderAlias parent

426− <+> parenthesized (commaSeparated (renderAliases refs))

427− <+> renderOnDeleteClause ondel

428− <+> renderOnUpdateClause onupd

429−

430−-- | A constraint synonym between types involved in a foreign key constraint.

431−type ForeignKeyed schema

432− child parent

433− table reftable

434− columns refcolumns

435− constraints cols

436− reftys tys =

437− ( Has child schema ('Table table)

438− , Has parent schema ('Table reftable)

439− , HasAll columns (TableToColumns table) tys

440− , reftable ~ (constraints :=> cols)

441− , HasAll refcolumns cols reftys

442− , SOP.AllZip SamePGType tys reftys

443− , Uniquely refcolumns constraints )

444−

445−-- | `OnDeleteClause` indicates what to do with rows that reference a deleted row.

446−data OnDeleteClause

447− = OnDeleteNoAction

448− -- ^ if any referencing rows still exist when the constraint is checked,

449− -- an error is raised

450− | OnDeleteRestrict -- ^ prevents deletion of a referenced row

451− | OnDeleteCascade

452− -- ^ specifies that when a referenced row is deleted,

453− -- row(s) referencing it should be automatically deleted as well

454− deriving (GHC.Generic,Show,Eq,Ord)

455−instance NFData OnDeleteClause

456−

457−-- | Render `OnDeleteClause`.

458−renderOnDeleteClause :: OnDeleteClause -> ByteString

459−renderOnDeleteClause = \case

460− OnDeleteNoAction -> "ON DELETE NO ACTION"

461− OnDeleteRestrict -> "ON DELETE RESTRICT"

462− OnDeleteCascade -> "ON DELETE CASCADE"

463−

464−-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked

465−-- when a referenced column is changed (updated).

466−data OnUpdateClause

467− = OnUpdateNoAction

468− -- ^ if any referencing rows has not changed when the constraint is checked,

469− -- an error is raised

470− | OnUpdateRestrict -- ^ prevents update of a referenced row

471− | OnUpdateCascade

472− -- ^ the updated values of the referenced column(s) should be copied

473− -- into the referencing row(s)

474− deriving (GHC.Generic,Show,Eq,Ord)

475−instance NFData OnUpdateClause

476−

477−-- | Render `OnUpdateClause`.

478−renderOnUpdateClause :: OnUpdateClause -> ByteString

479−renderOnUpdateClause = \case

480− OnUpdateNoAction -> "ON UPDATE NO ACTION"

481− OnUpdateRestrict -> "ON UPDATE RESTRICT"

482− OnUpdateCascade -> "ON UPDATE CASCADE"

483−

484−{-----------------------------------------

485−DROP statements

486−-----------------------------------------}

487−

488−-- | `dropTable` removes a table from the schema.

489−--

490−-- >>> :{

491−-- let

492−-- definition :: Definition '["muh_table" ::: 'Table t] '[]

493−-- definition = dropTable #muh_table

494−-- :}

495−--

496−-- >>> printSQL definition

497−-- DROP TABLE "muh_table";

498−dropTable

499− :: Has table schema ('Table t)

500− => Alias table -- ^ table to remove

501− -> Definition schema (Drop table schema)

502−dropTable tab = UnsafeDefinition $ "DROP TABLE" <+> renderAlias tab <> ";"

503−

504−{-----------------------------------------

505−ALTER statements

506−-----------------------------------------}

507−

508−-- | `alterTable` changes the definition of a table from the schema.

509−alterTable

510− :: KnownSymbol alias

511− => Alias alias -- ^ table to alter

512− -> AlterTable alias table schema -- ^ alteration to perform

513− -> Definition schema (Alter alias ('Table table) schema)

514−alterTable tab alteration = UnsafeDefinition $

515− "ALTER TABLE"

516− <+> renderAlias tab

517− <+> renderAlterTable alteration

518− <> ";"

519−

520−-- | `alterTableRename` changes the name of a table from the schema.

521−--

522−-- >>> printSQL $ alterTableRename #foo #bar

523−-- ALTER TABLE "foo" RENAME TO "bar";

524−alterTableRename

525− :: (KnownSymbol table0, KnownSymbol table1)

526− => Alias table0 -- ^ table to rename

527− -> Alias table1 -- ^ what to rename it

528− -> Definition schema (Rename table0 table1 schema)

529−alterTableRename table0 table1 = UnsafeDefinition $

530− "ALTER TABLE" <+> renderAlias table0

531− <+> "RENAME TO" <+> renderAlias table1 <> ";"

532−

533−-- | An `AlterTable` describes the alteration to perform on the columns

534−-- of a table.

535−newtype AlterTable

536− (alias :: Symbol)

537− (table :: TableType)

538− (schema :: SchemaType) =

539− UnsafeAlterTable {renderAlterTable :: ByteString}

540− deriving (GHC.Generic,Show,Eq,Ord,NFData)

541−

542−-- | An `addConstraint` adds a table constraint.

543−--

544−-- >>> :{

545−-- let

546−-- definition :: Definition

547−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

548−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

549−-- definition = alterTable #tab (addConstraint #positive (check (#col :* Nil) (#col .> 0)))

550−-- in printSQL definition

551−-- :}

552−-- ALTER TABLE "tab" ADD CONSTRAINT "positive" CHECK (("col" > 0));

553−addConstraint

554− :: ( KnownSymbol alias

555− , Has tab schema ('Table table0)

556− , table0 ~ (constraints :=> columns)

557− , table1 ~ (Create alias constraint constraints :=> columns) )

558− => Alias alias

559− -> TableConstraintExpression schema tab constraint

560− -- ^ constraint to add

561− -> AlterTable tab table1 schema

562−addConstraint alias constraint = UnsafeAlterTable $

563− "ADD" <+> "CONSTRAINT" <+> renderAlias alias

564− <+> renderTableConstraintExpression constraint

565−

566−-- | A `dropConstraint` drops a table constraint.

567−--

568−-- >>> :{

569−-- let

570−-- definition :: Definition

571−-- '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

572−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

573−-- definition = alterTable #tab (dropConstraint #positive)

574−-- in printSQL definition

575−-- :}

576−-- ALTER TABLE "tab" DROP CONSTRAINT "positive";

577−dropConstraint

578− :: ( KnownSymbol constraint

579− , Has tab schema ('Table table0)

580− , table0 ~ (constraints :=> columns)

581− , table1 ~ (Drop constraint constraints :=> columns) )

582− => Alias constraint

583− -- ^ constraint to drop

584− -> AlterTable tab table1 schema

585−dropConstraint constraint = UnsafeAlterTable $

586− "DROP" <+> "CONSTRAINT" <+> renderAlias constraint

587−

588−-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.

589−class AddColumn ty where

590− -- | `addColumn` adds a new column, initially filled with whatever

591− -- default value is given or with @NULL@.

592− --

593− -- >>> :{

594− -- let

595− -- definition :: Definition

596− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

597− -- '["tab" ::: 'Table ('[] :=>

598− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

599− -- , "col2" ::: 'Def :=> 'Null 'PGtext ])]

600− -- definition = alterTable #tab (addColumn #col2 (text & nullable & default_ "foo"))

601− -- in printSQL definition

602− -- :}

603− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL DEFAULT E'foo';

604− --

605− -- >>> :{

606− -- let

607− -- definition :: Definition

608− -- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

609− -- '["tab" ::: 'Table ('[] :=>

610− -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

611− -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]

612− -- definition = alterTable #tab (addColumn #col2 (text & nullable))

613− -- in printSQL definition

614− -- :}

615− -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL;

616− addColumn

617− :: ( KnownSymbol column

618− , Has tab schema ('Table table0)

619− , table0 ~ (constraints :=> columns)

620− , table1 ~ (constraints :=> Create column ty columns) )

621− => Alias column -- ^ column to add

622− -> ColumnTypeExpression schema ty -- ^ type of the new column

623− -> AlterTable tab table1 schema

624− addColumn column ty = UnsafeAlterTable $

625− "ADD COLUMN" <+> renderAlias column <+> renderColumnTypeExpression ty

626−instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)

627−instance {-# OVERLAPPABLE #-} AddColumn ('NoDef :=> 'Null ty)

628−

629−-- | A `dropColumn` removes a column. Whatever data was in the column

630−-- disappears. Table constraints involving the column are dropped, too.

631−-- However, if the column is referenced by a foreign key constraint of

632−-- another table, PostgreSQL will not silently drop that constraint.

633−--

634−-- >>> :{

635−-- let

636−-- definition :: Definition

637−-- '["tab" ::: 'Table ('[] :=>

638−-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

639−-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]

640−-- '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]

641−-- definition = alterTable #tab (dropColumn #col2)

642−-- in printSQL definition

643−-- :}

644−-- ALTER TABLE "tab" DROP COLUMN "col2";

645−dropColumn

646− :: ( KnownSymbol column

647− , Has tab schema ('Table table0)

648− , table0 ~ (constraints :=> columns)

649− , table1 ~ (constraints :=> Drop column columns) )

650− => Alias column -- ^ column to remove

651− -> AlterTable tab table1 schema

652−dropColumn column = UnsafeAlterTable $

653− "DROP COLUMN" <+> renderAlias column

654−

655−-- | A `renameColumn` renames a column.

656−--

657−-- >>> :{

658−-- let

659−-- definition :: Definition

660−-- '["tab" ::: 'Table ('[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4])]

661−-- '["tab" ::: 'Table ('[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4])]

662−-- definition = alterTable #tab (renameColumn #foo #bar)

663−-- in printSQL definition

664−-- :}

665−-- ALTER TABLE "tab" RENAME COLUMN "foo" TO "bar";

666−renameColumn

667− :: ( KnownSymbol column0

668− , KnownSymbol column1

669− , Has tab schema ('Table table0)

670− , table0 ~ (constraints :=> columns)

671− , table1 ~ (constraints :=> Rename column0 column1 columns) )

672− => Alias column0 -- ^ column to rename

673− -> Alias column1 -- ^ what to rename the column

674− -> AlterTable tab table1 schema

675−renameColumn column0 column1 = UnsafeAlterTable $

676− "RENAME COLUMN" <+> renderAlias column0 <+> "TO" <+> renderAlias column1

677−

678−-- | An `alterColumn` alters a single column.

679−alterColumn

680− :: ( KnownSymbol column

681− , Has tab schema ('Table table0)

682− , table0 ~ (constraints :=> columns)

683− , Has column columns ty0

684− , tables1 ~ (constraints :=> Alter column ty1 columns))

685− => Alias column -- ^ column to alter

686− -> AlterColumn schema ty0 ty1 -- ^ alteration to perform

687− -> AlterTable tab table1 schema

688−alterColumn column alteration = UnsafeAlterTable $

689− "ALTER COLUMN" <+> renderAlias column <+> renderAlterColumn alteration

690−

691−-- | An `AlterColumn` describes the alteration to perform on a single column.

692−newtype AlterColumn (schema :: SchemaType) (ty0 :: ColumnType) (ty1 :: ColumnType) =

693− UnsafeAlterColumn {renderAlterColumn :: ByteString}

694− deriving (GHC.Generic,Show,Eq,Ord,NFData)

695−

696−-- | A `setDefault` sets a new default for a column. Note that this doesn't

697−-- affect any existing rows in the table, it just changes the default for

698−-- future insert and update commands.

699−--

700−-- >>> :{

701−-- let

702−-- definition :: Definition

703−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

704−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

705−-- definition = alterTable #tab (alterColumn #col (setDefault 5))

706−-- in printSQL definition

707−-- :}

708−-- ALTER TABLE "tab" ALTER COLUMN "col" SET DEFAULT 5;

709−setDefault

710− :: Expression schema '[] 'Ungrouped '[] ty -- ^ default value to set

711− -> AlterColumn schema (constraint :=> ty) ('Def :=> ty)

712−setDefault expression = UnsafeAlterColumn $

713− "SET DEFAULT" <+> renderExpression expression

714−

715−-- | A `dropDefault` removes any default value for a column.

716−--

717−-- >>> :{

718−-- let

719−-- definition :: Definition

720−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

721−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

722−-- definition = alterTable #tab (alterColumn #col dropDefault)

723−-- in printSQL definition

724−-- :}

725−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP DEFAULT;

726−dropDefault :: AlterColumn schema ('Def :=> ty) ('NoDef :=> ty)

727−dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"

728−

729−-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.

730−-- The constraint will be checked immediately, so the table data must satisfy

731−-- the constraint before it can be added.

732−--

733−-- >>> :{

734−-- let

735−-- definition :: Definition

736−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

737−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

738−-- definition = alterTable #tab (alterColumn #col setNotNull)

739−-- in printSQL definition

740−-- :}

741−-- ALTER TABLE "tab" ALTER COLUMN "col" SET NOT NULL;

742−setNotNull

743− :: AlterColumn schema (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)

744−setNotNull = UnsafeAlterColumn $ "SET NOT NULL"

745−

746−-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.

747−--

748−-- >>> :{

749−-- let

750−-- definition :: Definition

751−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

752−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

753−-- definition = alterTable #tab (alterColumn #col dropNotNull)

754−-- in printSQL definition

755−-- :}

756−-- ALTER TABLE "tab" ALTER COLUMN "col" DROP NOT NULL;

757−dropNotNull

758− :: AlterColumn schema (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)

759−dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"

760−

761−-- | An `alterType` converts a column to a different data type.

762−-- This will succeed only if each existing entry in the column can be

763−-- converted to the new type by an implicit cast.

764−--

765−-- >>> :{

766−-- let

767−-- definition :: Definition

768−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

769−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]

770−-- definition =

771−-- alterTable #tab (alterColumn #col (alterType (numeric & notNullable)))

772−-- in printSQL definition

773−-- :}

774−-- ALTER TABLE "tab" ALTER COLUMN "col" TYPE numeric NOT NULL;

775−alterType :: ColumnTypeExpression schema ty -> AlterColumn schema ty0 ty

776−alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty

777−

778−-- | Create a view.

779−--

780−-- >>> :{

781−-- let

782−-- definition :: Definition

783−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]

784−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

785−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]

786−-- definition =

787−-- createView #bc (select (#b :* #c :* Nil) (from (table #abc)))

788−-- in printSQL definition

789−-- :}

790−-- CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";

791−createView

792− :: KnownSymbol view

793− => Alias view -- ^ the name of the view to add

794− -> Query schema '[] relation

795− -- ^ query

796− -> Definition schema (Create view ('View relation) schema)

797−createView alias query = UnsafeDefinition $

798− "CREATE" <+> "VIEW" <+> renderAlias alias <+> "AS"

799− <+> renderQuery query <> ";"

800−

801−-- | Drop a view.

802−--

803−-- >>> :{

804−-- let

805−-- definition :: Definition

806−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

807−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]

808−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]

809−-- definition = dropView #bc

810−-- in printSQL definition

811−-- :}

812−-- DROP VIEW "bc";

813−dropView

814− :: Has view schema ('View v)

815− => Alias view -- ^ view to remove

816− -> Definition schema (Drop view schema)

817−dropView v = UnsafeDefinition $ "DROP VIEW" <+> renderAlias v <> ";"

818−

819−-- | Enumerated types are created using the `createTypeEnum` command, for example

820−--

821−-- >>> printSQL $ createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy" :* Nil)

822−-- CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');

823−createTypeEnum

824− :: (KnownSymbol enum, SOP.All KnownSymbol labels)

825− => Alias enum

826− -- ^ name of the user defined enumerated type

827− -> NP PGlabel labels

828− -- ^ labels of the enumerated type

829− -> Definition schema (Create enum ('Typedef ('PGenum labels)) schema)

830−createTypeEnum enum labels = UnsafeDefinition $

831− "CREATE" <+> "TYPE" <+> renderAlias enum <+> "AS" <+> "ENUM" <+>

832− parenthesized (commaSeparated (renderLabels labels)) <> ";"

833−

834−-- | Enumerated types can also be generated from a Haskell type, for example

835−--

836−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

837−-- >>> instance SOP.Generic Schwarma

838−-- >>> instance SOP.HasDatatypeInfo Schwarma

839−-- >>> printSQL $ createTypeEnumFrom @Schwarma #schwarma

840−-- CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');

841−createTypeEnumFrom

842− :: forall hask enum schema.

843− ( SOP.Generic hask

844− , SOP.All KnownSymbol (LabelsFrom hask)

845− , KnownSymbol enum

846− )

847− => Alias enum

848− -- ^ name of the user defined enumerated type

849− -> Definition schema (Create enum ('Typedef (EnumFrom hask)) schema)

850−createTypeEnumFrom enum = createTypeEnum enum

851− (SOP.hpure label :: NP PGlabel (LabelsFrom hask))

852−

853−-- | `createTypeComposite` creates a composite type. The composite type is

854−-- specified by a list of attribute names and data types.

855−--

856−-- >>> printSQL $ createTypeComposite #complex (float8 `As` #real :* float8 `As` #imaginary :* Nil)

857−-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

858−createTypeComposite

859− :: (KnownSymbol ty, SOP.SListI fields)

860− => Alias ty

861− -- ^ name of the user defined composite type

862− -> NP (Aliased (TypeExpression schema)) fields

863− -- ^ list of attribute names and data types

864− -> Definition schema (Create ty ('Typedef ('PGcomposite fields)) schema)

865−createTypeComposite ty fields = UnsafeDefinition $

866− "CREATE" <+> "TYPE" <+> renderAlias ty <+> "AS" <+> parenthesized

867− (renderCommaSeparated renderField fields) <> ";"

868− where

869− renderField :: Aliased (TypeExpression schema) x -> ByteString

870− renderField (typ `As` field) =

871− renderAlias field <+> renderTypeExpression typ

872−

873−-- | Composite types can also be generated from a Haskell type, for example

874−--

875−-- >>> data Complex = Complex {real :: Maybe Double, imaginary :: Maybe Double} deriving GHC.Generic

876−-- >>> instance SOP.Generic Complex

877−-- >>> instance SOP.HasDatatypeInfo Complex

878−-- >>> printSQL $ createTypeCompositeFrom @Complex #complex

879−-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

880−createTypeCompositeFrom

881− :: forall hask ty schema.

882− ( ZipAliased (FieldNamesFrom hask) (FieldTypesFrom hask)

883− , SOP.All (PGTyped schema) (FieldTypesFrom hask)

884− , KnownSymbol ty

885− )

886− => Alias ty

887− -- ^ name of the user defined composite type

888− -> Definition schema (Create ty ( 'Typedef (CompositeFrom hask)) schema)

889−createTypeCompositeFrom ty = createTypeComposite ty $ zipAs

890− (SOP.hpure Alias :: NP Alias (FieldNamesFrom hask))

891− (SOP.hcpure (SOP.Proxy :: SOP.Proxy (PGTyped schema)) pgtype

892− :: NP (TypeExpression schema) (FieldTypesFrom hask))

893−

894−-- | Drop a type.

895−--

896−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

897−-- >>> instance SOP.Generic Schwarma

898−-- >>> instance SOP.HasDatatypeInfo Schwarma

899−-- >>> printSQL (dropType #schwarma :: Definition '["schwarma" ::: 'Typedef (EnumFrom Schwarma)] '[])

900−-- DROP TYPE "schwarma";

901−dropType

902− :: Has tydef schema ('Typedef ty)

903− => Alias tydef

904− -- ^ name of the user defined type

905− -> Definition schema (Drop tydef schema)

906−dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderAlias tydef <> ";"

907−

908−-- | `ColumnTypeExpression`s are used in `createTable` commands.

909−newtype ColumnTypeExpression (schema :: SchemaType) (ty :: ColumnType)

910− = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }

911− deriving (GHC.Generic,Show,Eq,Ord,NFData)

912−

913−-- | used in `createTable` commands as a column constraint to note that

914−-- @NULL@ may be present in a column

915−nullable

916− :: TypeExpression schema ty

917− -> ColumnTypeExpression schema ('NoDef :=> 'Null ty)

918−nullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NULL"

919−

920−-- | used in `createTable` commands as a column constraint to ensure

921−-- @NULL@ is not present in a column

922−notNullable

923− :: TypeExpression schema ty

924− -> ColumnTypeExpression schema (def :=> 'NotNull ty)

925−notNullable ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NOT NULL"

926−

927−-- | used in `createTable` commands as a column constraint to give a default

928−default_

929− :: Expression schema '[] 'Ungrouped '[] ty

930− -> ColumnTypeExpression schema ('NoDef :=> ty)

931− -> ColumnTypeExpression schema ('Def :=> ty)

932−default_ x ty = UnsafeColumnTypeExpression $

933− renderColumnTypeExpression ty <+> "DEFAULT" <+> renderExpression x

934−

935−-- | not a true type, but merely a notational convenience for creating

936−-- unique identifier columns with type `PGint2`

937−serial2, smallserial

938− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint2)

939−serial2 = UnsafeColumnTypeExpression "serial2"

940−smallserial = UnsafeColumnTypeExpression "smallserial"

941−-- | not a true type, but merely a notational convenience for creating

942−-- unique identifier columns with type `PGint4`

943−serial4, serial

944− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint4)

945−serial4 = UnsafeColumnTypeExpression "serial4"

946−serial = UnsafeColumnTypeExpression "serial"

947−-- | not a true type, but merely a notational convenience for creating

948−-- unique identifier columns with type `PGint8`

949−serial8, bigserial

950− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint8)

951−serial8 = UnsafeColumnTypeExpression "serial8"

952−bigserial = UnsafeColumnTypeExpression "bigserial"

squeal-postgresql/src/Squeal/PostgreSQL/Definition/Function.hsnew file+238

@@ -0,0 +1,238 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.Function

3+Description: Create and drop function and operator definitions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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+343−1121

@@ -1,484 +1,382 @@

1{-|

2−Module: Squeal.PostgreSQL.Query

2+Module: Squeal.PostgreSQL.Expression

3Description: Squeal expressions

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

5Maintainer: eitan@morphism.tech

6Stability: experimental

8Squeal expressions are the atoms used to build statements.

9-}

11−{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}

12{-# LANGUAGE

11{-# LANGUAGE

13 AllowAmbiguousTypes

12 AllowAmbiguousTypes

13+ , ConstraintKinds

14 , DeriveGeneric

15 , FlexibleContexts

16 , FlexibleInstances

17 , FunctionalDependencies

18+ , GADTs

18 , GeneralizedNewtypeDeriving

19 , GeneralizedNewtypeDeriving

19 , LambdaCase

20 , LambdaCase

20 , MagicHash

21 , MagicHash

21 , OverloadedStrings

22 , OverloadedStrings

22 , ScopedTypeVariables

23 , ScopedTypeVariables

24+ , StandaloneDeriving

23 , TypeApplications

25 , TypeApplications

24 , TypeFamilies

26 , TypeFamilies

25 , TypeInType

27 , TypeInType

26 , TypeOperators

28 , TypeOperators

27 , UndecidableInstances

29 , UndecidableInstances

30+ , RankNTypes

28#-}

31#-}

30module Squeal.PostgreSQL.Expression

33module Squeal.PostgreSQL.Expression

31 ( -- * Expression

34 ( -- * Expression

32− Expression (UnsafeExpression, renderExpression)

35+ Expression (..)

33− , HasParameter (parameter)

36+ , Expr

34− , param

37+ , type (-->)

35− -- ** Null

38+ , FunctionDB

36− , null_

37− , notNull

38− , coalesce

39− , fromNull

40− , isNull

41− , isNotNull

42− , matchNull

43− , nullIf

44− -- ** Collections

45− , array

46− , row

47− -- ** Functions

48− , unsafeBinaryOp

49− , unsafeUnaryOp

50 , unsafeFunction

39 , unsafeFunction

51− , atan2_

40+ , function

52− , cast

41+ , unsafeLeftOp

53− , quot_

42+ , leftOp

54− , rem_

43+ , unsafeRightOp

55− , trunc

44+ , rightOp

56− , round_

45+ , Operator

57− , ceiling_

46+ , OperatorDB

58− , greatest

47+ , unsafeBinaryOp

59− , least

48+ , binaryOp

60− -- ** Conditions

49+ , FunctionVar

61− , Condition

50+ , unsafeFunctionVar

62− , true

51+ , type (--->)

63− , false

52+ , FunctionNDB

64− , not_

53+ , unsafeFunctionN

65− , (.&&)

54+ , functionN

66− , (.||)

55+ , PGSubset (..)

67− , caseWhenThenElse

56+ , PGIntersect (..)

68− , ifThenElse

69− , (.==)

70− , (./=)

71− , (.>=)

72− , (.<)

73− , (.<=)

74− , (.>)

75− -- ** Time

76− , currentDate

77− , currentTime

78− , currentTimestamp

79− , localTime

80− , localTimestamp

81− -- ** Text

82− , lower

83− , upper

84− , charLength

85− , like

86− -- ** Aggregation

87− , unsafeAggregate, unsafeAggregateDistinct

88− , sum_, sumDistinct

89− , PGAvg (avg, avgDistinct)

90− , bitAnd, bitOr, boolAnd, boolOr

91− , bitAndDistinct, bitOrDistinct, boolAndDistinct, boolOrDistinct

92− , countStar

93− , count, countDistinct

94− , every, everyDistinct

95− , max_, maxDistinct, min_, minDistinct

96− -- * Types

97− , TypeExpression (UnsafeTypeExpression, renderTypeExpression)

98− , PGTyped (pgtype)

99− , bool

100− , int2

101− , smallint

102− , int4

103− , int

104− , integer

105− , int8

106− , bigint

107− , numeric

108− , float4

109− , real

110− , float8

111− , doublePrecision

112− , text

113− , char

114− , character

115− , varchar

116− , characterVarying

117− , bytea

118− , timestamp

119− , timestampWithTimeZone

120− , date

121− , time

122− , timeWithTimeZone

123− , interval

124− , uuid

125− , inet

126− , json

127− , jsonb

128− , vararray

129− , fixarray

130 -- * Re-export

57 -- * Re-export

131 , (&)

58 , (&)

132− , NP ((:*), Nil)

59+ , K (..)

60+ , unK

133 ) where

61 ) where

134

135import Control.Category

63import Control.Category

136import Control.DeepSeq

64import Control.DeepSeq

137import Data.ByteString (ByteString)

65import Data.ByteString (ByteString)

138import Data.Function ((&))

66import Data.Function ((&))

139−import Data.Semigroup

67+import Data.Semigroup hiding (All)

140−import Data.Ratio

141import Data.String

68import Data.String

142−import Generics.SOP hiding (from)

69+import Generics.SOP hiding (All, from)

143import GHC.OverloadedLabels

70import GHC.OverloadedLabels

144import GHC.TypeLits

71import GHC.TypeLits

72+import Numeric

145import Prelude hiding (id, (.))

73import Prelude hiding (id, (.))

146

147import qualified GHC.Generics as GHC

75import qualified GHC.Generics as GHC

148

77+import Squeal.PostgreSQL.Alias

78+import Squeal.PostgreSQL.List

149import Squeal.PostgreSQL.Render

79import Squeal.PostgreSQL.Render

150import Squeal.PostgreSQL.Schema

80import Squeal.PostgreSQL.Schema

151

82+-- $setup

83+-- >>> import Squeal.PostgreSQL

84+

152{-----------------------------------------

85{-----------------------------------------

153column expressions

86column expressions

154-----------------------------------------}

87-----------------------------------------}

155

156{- | `Expression`s are used in a variety of contexts,

89{- | `Expression`s are used in a variety of contexts,

90+such as in the target `Squeal.PostgreSQL.Query.List` of the

157−such as in the target list of the `Squeal.PostgreSQL.Query.select` command,

91+`Squeal.PostgreSQL.Query.select` command,

158as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or

92as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or

159`Squeal.PostgreSQL.Manipulation.update`,

93`Squeal.PostgreSQL.Manipulation.update`,

160−or in search `Condition`s in a number of commands.

94+or in search `Squeal.PostgreSQL.Logic.Condition`s in a number of commands.

161

162The expression syntax allows the calculation of

96The expression syntax allows the calculation of

163values from primitive expression using arithmetic, logical,

97values from primitive expression using arithmetic, logical,

164and other operations.

98and other operations.

99+

100+The type parameters of `Expression` are

101+

102+* @outer :: @ `FromType`, the @from@ clauses of any outer queries in which

103+ the `Expression` is a correlated subquery expression;

104+* @commons :: @ `FromType`, the `Squeal.PostgreSQL.Query.CommonTableExpression`s

105+ that are in scope for the `Expression`;

106+* @grp :: @ `Grouping`, the `Grouping` of the @from@ clause which may limit

107+ which columns may be referenced by alias;

108+* @schemas :: @ `SchemasType`, the schemas of your database that are in

109+ scope for the `Expression`;

110+* @from :: @ `FromType`, the @from@ clause which the `Expression` may use

111+ to reference columns by alias;

112+* @ty :: @ `NullityType`, the type of the `Expression`.

165-}

113-}

166newtype Expression

114newtype Expression

167− (schema :: SchemaType)

115+ (outer :: FromType)

168− (relations :: RelationsType)

116+ (commons :: FromType)

169− (grouping :: Grouping)

117+ (grp :: Grouping)

118+ (schemas :: SchemasType)

170 (params :: [NullityType])

119 (params :: [NullityType])

120+ (from :: FromType)

171 (ty :: NullityType)

121 (ty :: NullityType)

172 = UnsafeExpression { renderExpression :: ByteString }

122 = UnsafeExpression { renderExpression :: ByteString }

173 deriving (GHC.Generic,Show,Eq,Ord,NFData)

123 deriving (GHC.Generic,Show,Eq,Ord,NFData)

174−

175−instance RenderSQL (Expression schema relations grouping params ty) where

124+instance RenderSQL (Expression outer commons grp schemas params from ty) where

176 renderSQL = renderExpression

125 renderSQL = renderExpression

177

126

178−{- | A `HasParameter` constraint is used to indicate a value that is

127+-- | An `Expr` is a closed `Expression`.

179−supplied externally to a SQL statement.

128+-- It is a F@RankNType@ but don't be scared.

180−`Squeal.PostgreSQL.PQ.manipulateParams`,

129+-- Think of it as an expression which sees no

181−`Squeal.PostgreSQL.PQ.queryParams` and

130+-- namespaces, so you can't use parameters

182−`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values

131+-- or alias references. It can be used as

183−separately from the SQL command string, in which case `param`s are used to

132+-- a simple piece of more complex `Expression`s.

184−refer to the out-of-line data values.

133+type Expr x

134+ = forall outer commons grp schemas params from

135+ . Expression outer commons grp schemas params from x

136+ -- ^ cannot reference aliases

137+

138+-- | A @RankNType@ for binary operators.

139+type Operator x1 x2 y

140+ = forall outer commons grp schemas params from

141+ . Expression outer commons grp schemas params from x1

142+ -- ^ left input

143+ -> Expression outer commons grp schemas params from x2

144+ -- ^ right input

145+ -> Expression outer commons grp schemas params from y

146+ -- ^ output

147+

148+type OperatorDB schemas x1 x2 y

149+ = forall outer commons grp params from

150+ . Expression outer commons grp schemas params from x1

151+ -- ^ left input

152+ -> Expression outer commons grp schemas params from x2

153+ -- ^ right input

154+ -> Expression outer commons grp schemas params from y

155+ -- ^ output

156+

157+-- | A @RankNType@ for functions with a single argument.

158+-- These could be either function calls or unary operators.

159+-- This is a subtype of the usual Haskell function type `Prelude.->`,

160+-- indeed a subcategory as it is closed under the usual

161+-- `Prelude..` and `Prelude.id`.

162+type (-->) x y

163+ = forall outer commons grp schemas params from

164+ . Expression outer commons grp schemas params from x

165+ -- ^ input

166+ -> Expression outer commons grp schemas params from y

167+ -- ^ output

168+

169+type FunctionDB schemas x y

170+ = forall outer commons grp params from

171+ . Expression outer commons grp schemas params from x

172+ -- ^ input

173+ -> Expression outer commons grp schemas params from y

174+ -- ^ output

175+

176+{- | A @RankNType@ for functions with a fixed-length list of heterogeneous arguments.

177+Use the `*:` operator to end your argument lists, like so.

178+

179+>>> printSQL (unsafeFunctionN "fun" (true :* false :* localTime *: true))

180+fun(TRUE, FALSE, LOCALTIME, TRUE)

185-}

181-}

186−class KnownNat n => HasParameter

182+type (--->) xs y

187− (n :: Nat)

183+ = forall outer commons grp schemas params from

188− (schema :: SchemaType)

184+ . NP (Expression outer commons grp schemas params from) xs

189− (params :: [NullityType])

185+ -- ^ inputs

190− (ty :: NullityType)

186+ -> Expression outer commons grp schemas params from y

191− | n params -> ty where

187+ -- ^ output

192− -- | `parameter` takes a `Nat` using type application and a `TypeExpression`.

188+

193− --

189+type FunctionNDB schemas xs y

194− -- >>> let expr = parameter @1 int4 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)

190+ = forall outer commons grp params from

195− -- >>> printSQL expr

191+ . NP (Expression outer commons grp schemas params from) xs

196− -- ($1 :: int4)

192+ -- ^ inputs

197− parameter

193+ -> Expression outer commons grp schemas params from y

198− :: TypeExpression schema (PGTypeOf ty)

194+ -- ^ output

199− -> Expression schema relations grouping params ty

195+

196+{- | A @RankNType@ for functions with a variable-length list of

197+homogeneous arguments and at least 1 more argument.

198+-}

199+type FunctionVar x0 x1 y

200+ = forall outer commons grp schemas params from

201+ . [Expression outer commons grp schemas params from x0]

202+ -- ^ inputs

203+ -> Expression outer commons grp schemas params from x1

204+ -- ^ must have at least 1 input

205+ -> Expression outer commons grp schemas params from y

206+ -- ^ output

207+

208+{- | >>> printSQL (unsafeFunctionVar "greatest" [true, null_] false)

209+greatest(TRUE, NULL, FALSE)

210+-}

211+unsafeFunctionVar :: ByteString -> FunctionVar x0 x1 y

200− parameter ty = UnsafeExpression $ parenthesized $

212+unsafeFunctionVar fun xs x = UnsafeExpression $ fun <> parenthesized

201− "$" <> renderNat (Proxy @n) <+> "::"

213+ (commaSeparated (renderSQL <$> xs) <> ", " <> renderSQL x)

202− <+> renderTypeExpression ty

214+

203−instance {-# OVERLAPPING #-} HasParameter 1 schema (ty1:tys) ty1

215+instance (HasUnique tab (Join outer from) row, Has col row ty)

204−instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) schema params ty)

216+ => IsLabel col (Expression outer commons 'Ungrouped schemas params from ty) where

205− => HasParameter n schema (ty' : params) ty

217+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)

206−

218+instance (HasUnique tab (Join outer from) row, Has col row ty, tys ~ '[ty])

207−-- | `param` takes a `Nat` using type application and for basic types,

219+ => IsLabel col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where

208−-- infers a `TypeExpression`.

220+ fromLabel = fromLabel @col :* Nil

209−--

210−-- >>> let expr = param @1 :: Expression sch rels grp '[ 'Null 'PGint4] ('Null 'PGint4)

211−-- >>> printSQL expr

212−-- ($1 :: int4)

213−param

214− :: forall n schema params relations grouping ty

215− . (PGTyped schema (PGTypeOf ty), HasParameter n schema params ty)

216− => Expression schema relations grouping params ty -- ^ param

217−param = parameter @n pgtype

218−

219−instance (HasUnique relation relations columns, Has column columns ty)

221+instance (HasUnique tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))

222+ => IsLabel col

220− => IsLabel column (Expression schema relations 'Ungrouped params ty) where

223+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where

221− fromLabel = UnsafeExpression $ renderAlias (Alias @column)

224+ fromLabel = fromLabel @col `As` Alias

222−instance (HasUnique relation relations columns, Has column columns ty)

225+instance (HasUnique tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])

223− => IsLabel column

226+ => IsLabel col

224− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where

227+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where

225− fromLabel = fromLabel @column `As` Alias @column

228+ fromLabel = fromLabel @col :* Nil

226−instance (HasUnique relation relations columns, Has column columns ty)

229+

227− => IsLabel column

230+instance (Has tab (Join outer from) row, Has col row ty)

228− (NP (Aliased (Expression schema relations 'Ungrouped params)) '[column ::: ty]) where

231+ => IsQualified tab col (Expression outer commons 'Ungrouped schemas params from ty) where

229− fromLabel = fromLabel @column :* Nil

232+ tab ! col = UnsafeExpression $

230−

233+ renderSQL tab <> "." <> renderSQL col

231−instance (Has relation relations columns, Has column columns ty)

234+instance (Has tab (Join outer from) row, Has col row ty, tys ~ '[ty])

232− => IsQualified relation column (Expression schema relations 'Ungrouped params ty) where

235+ => IsQualified tab col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where

233− relation ! column = UnsafeExpression $

236+ tab ! col = tab ! col :* Nil

234− renderAlias relation <> "." <> renderAlias column

235−instance (Has relation relations columns, Has column columns ty)

237+instance (Has tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))

236− => IsQualified relation column

238+ => IsQualified tab col

237− (Aliased (Expression schema relations 'Ungrouped params) (column ::: ty)) where

239+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where

238− relation ! column = relation ! column `As` column

240+ tab ! col = tab ! col `As` col

239−instance (Has relation relations columns, Has column columns ty)

241+instance (Has tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])

240− => IsQualified relation column

242+ => IsQualified tab col

241− (NP (Aliased (Expression schema relations 'Ungrouped params)) '[column ::: ty]) where

243+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where

242− relation ! column = relation ! column :* Nil

244+ tab ! col = tab ! col :* Nil

243

245

244instance

246instance

245− ( HasUnique relation relations columns

247+ ( HasUnique tab (Join outer from) row

246− , Has column columns ty

248+ , Has col row ty

247− , GroupedBy relation column bys

249+ , GroupedBy tab col bys

248− ) => IsLabel column

250+ ) => IsLabel col

249− (Expression schema relations ('Grouped bys) params ty) where

251+ (Expression outer commons ('Grouped bys) schemas params from ty) where

250− fromLabel = UnsafeExpression $ renderAlias (Alias @column)

252+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)

251instance

253instance

252− ( HasUnique relation relations columns

254+ ( HasUnique tab (Join outer from) row

253− , Has column columns ty

255+ , Has col row ty

254− , GroupedBy relation column bys

256+ , GroupedBy tab col bys

257+ , tys ~ '[ty]

255− ) => IsLabel column

258+ ) => IsLabel col

256− ( Aliased (Expression schema relations ('Grouped bys) params)

259+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where

257− (column ::: ty) ) where

258− fromLabel = fromLabel @column `As` Alias @column

260+ fromLabel = fromLabel @col :* Nil

259instance

261instance

260− ( HasUnique relation relations columns

262+ ( HasUnique tab (Join outer from) row

261− , Has column columns ty

263+ , Has col row ty

262− , GroupedBy relation column bys

264+ , GroupedBy tab col bys

265+ , column ~ (col ::: ty)

263− ) => IsLabel column

266+ ) => IsLabel col

264− ( NP (Aliased (Expression schema relations ('Grouped bys) params))

267+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where

265− '[column ::: ty] ) where

268+ fromLabel = fromLabel @col `As` Alias

269+instance

270+ ( HasUnique tab (Join outer from) row

271+ , Has col row ty

272+ , GroupedBy tab col bys

273+ , columns ~ '[col ::: ty]

274+ ) => IsLabel col

275+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where

266− fromLabel = fromLabel @column :* Nil

276+ fromLabel = fromLabel @col :* Nil

267

277

268instance

278instance

269− ( Has relation relations columns

279+ ( Has tab (Join outer from) row

270− , Has column columns ty

280+ , Has col row ty

271− , GroupedBy relation column bys

281+ , GroupedBy tab col bys

272− ) => IsQualified relation column

282+ ) => IsQualified tab col

273− (Expression schema relations ('Grouped bys) params ty) where

283+ (Expression outer commons ('Grouped bys) schemas params from ty) where

274− relation ! column = UnsafeExpression $

284+ tab ! col = UnsafeExpression $

275− renderAlias relation <> "." <> renderAlias column

285+ renderSQL tab <> "." <> renderSQL col

276instance

286instance

277− ( Has relation relations columns

287+ ( Has tab (Join outer from) row

278− , Has column columns ty

288+ , Has col row ty

279− , GroupedBy relation column bys

289+ , GroupedBy tab col bys

290+ , tys ~ '[ty]

280− ) => IsQualified relation column

291+ ) => IsQualified tab col

281− (Aliased (Expression schema relations ('Grouped bys) params)

292+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where

282− (column ::: ty)) where

293+ tab ! col = tab ! col :* Nil

283− relation ! column = relation ! column `As` column

284instance

294instance

285− ( Has relation relations columns

295+ ( Has tab (Join outer from) row

286− , Has column columns ty

296+ , Has col row ty

287− , GroupedBy relation column bys

297+ , GroupedBy tab col bys

298+ , column ~ (col ::: ty)

288− ) => IsQualified relation column

299+ ) => IsQualified tab col

300+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where

301+ tab ! col = tab ! col `As` col

302+instance

303+ ( Has tab (Join outer from) row

304+ , Has col row ty

305+ , GroupedBy tab col bys

306+ , columns ~ '[col ::: ty]

307+ ) => IsQualified tab col

289− ( NP (Aliased (Expression schema relations ('Grouped bys) params))

308+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where

290− '[column ::: ty]) where

309+ tab ! col = tab ! col :* Nil

291− relation ! column = relation ! column :* Nil

292−

293−-- | analagous to `Nothing`

294−--

295−-- >>> printSQL null_

296−-- NULL

297−null_ :: Expression schema rels grouping params ('Null ty)

298−null_ = UnsafeExpression "NULL"

299−

300−-- | analagous to `Just`

301−--

302−-- >>> printSQL $ notNull true

303−-- TRUE

304−notNull

305− :: Expression schema rels grouping params ('NotNull ty)

306− -> Expression schema rels grouping params ('Null ty)

307−notNull = UnsafeExpression . renderExpression

308−

309−-- | return the leftmost value which is not NULL

310−--

311−-- >>> printSQL $ coalesce [null_, notNull true] false

312−-- COALESCE(NULL, TRUE, FALSE)

313−coalesce

314− :: [Expression schema relations grouping params ('Null ty)]

315− -- ^ @NULL@s may be present

316− -> Expression schema relations grouping params ('NotNull ty)

317− -- ^ @NULL@ is absent

318− -> Expression schema relations grouping params ('NotNull ty)

319−coalesce nullxs notNullx = UnsafeExpression $

320− "COALESCE" <> parenthesized (commaSeparated

321− ((renderExpression <$> nullxs) <> [renderExpression notNullx]))

322−

323−-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@

324−--

325−-- >>> printSQL $ fromNull true null_

326−-- COALESCE(NULL, TRUE)

327−fromNull

328− :: Expression schema relations grouping params ('NotNull ty)

329− -- ^ what to convert @NULL@ to

330− -> Expression schema relations grouping params ('Null ty)

331− -> Expression schema relations grouping params ('NotNull ty)

332−fromNull notNullx nullx = coalesce [nullx] notNullx

333−

334−-- | >>> printSQL $ null_ & isNull

335−-- NULL IS NULL

336−isNull

337− :: Expression schema relations grouping params ('Null ty)

338− -- ^ possibly @NULL@

339− -> Condition schema relations grouping params

340−isNull x = UnsafeExpression $ renderExpression x <+> "IS NULL"

341−

342−-- | >>> printSQL $ null_ & isNotNull

343−-- NULL IS NOT NULL

344−isNotNull

345− :: Expression schema relations grouping params ('Null ty)

346− -- ^ possibly @NULL@

347− -> Condition schema relations grouping params

348−isNotNull x = UnsafeExpression $ renderExpression x <+> "IS NOT NULL"

349−

350−-- | analagous to `maybe` using @IS NULL@

351−--

352−-- >>> printSQL $ matchNull true not_ null_

353−-- CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END

354−matchNull

355− :: Expression schema relations grouping params (nullty)

356− -- ^ what to convert @NULL@ to

357− -> ( Expression schema relations grouping params ('NotNull ty)

358− -> Expression schema relations grouping params (nullty) )

359− -- ^ function to perform when @NULL@ is absent

360− -> Expression schema relations grouping params ('Null ty)

361− -> Expression schema relations grouping params (nullty)

362−matchNull y f x = ifThenElse (isNull x) y

363− (f (UnsafeExpression (renderExpression x)))

364−

365−{-| right inverse to `fromNull`, if its arguments are equal then

366−`nullIf` gives @NULL@.

367−

368−>>> :set -XTypeApplications -XDataKinds

369−>>> let expr = nullIf false (param @1) :: Expression schema rels grp '[ 'NotNull 'PGbool] ('Null 'PGbool)

370−>>> printSQL expr

371−NULL IF (FALSE, ($1 :: bool))

372−-}

373−nullIf

374− :: Expression schema relations grouping params ('NotNull ty)

375− -- ^ @NULL@ is absent

376− -> Expression schema relations grouping params ('NotNull ty)

377− -- ^ @NULL@ is absent

378− -> Expression schema relations grouping params ('Null ty)

379−nullIf x y = UnsafeExpression $ "NULL IF" <+> parenthesized

380− (renderExpression x <> ", " <> renderExpression y)

381−

382−-- | >>> printSQL $ array [null_, notNull false, notNull true]

383−-- ARRAY[NULL, FALSE, TRUE]

384−array

385− :: [Expression schema relations grouping params ('Null ty)]

386− -- ^ array elements

387− -> Expression schema relations grouping params (nullity ('PGvararray ty))

388−array xs = UnsafeExpression $

389− "ARRAY[" <> commaSeparated (renderExpression <$> xs) <> "]"

390

310

391instance (KnownSymbol label, label `In` labels) => IsPGlabel label

311instance (KnownSymbol label, label `In` labels) => IsPGlabel label

392− (Expression schema relations grouping params (nullity ('PGenum labels))) where

312+ (Expression outer commons grp schemas params from (null ('PGenum labels))) where

393− label = UnsafeExpression $ renderLabel (PGlabel @label)

313+ label = UnsafeExpression $ renderSQL (PGlabel @label)

394−

395−-- | A row constructor is an expression that builds a row value

396−-- (also called a composite value) using values for its member fields.

397−--

398−-- >>> type Complex = PGcomposite '["real" ::: 'PGfloat8, "imaginary" ::: 'PGfloat8]

399−-- >>> let i = row (0 `As` #real :* 1 `As` #imaginary :* Nil) :: Expression '[] '[] 'Ungrouped '[] ('NotNull Complex)

400−-- >>> printSQL i

401−-- ROW(0, 1)

402−row

403− :: SListI (Nulls fields)

404− => NP (Aliased (Expression schema relations grouping params)) (Nulls fields)

405− -- ^ zero or more expressions for the row field values

406− -> Expression schema relations grouping params (nullity ('PGcomposite fields))

407−row exprs = UnsafeExpression $ "ROW" <> parenthesized

408− (renderCommaSeparated (\ (expr `As` _) -> renderExpression expr) exprs)

409−

410−instance Has field fields ty => IsLabel field

411− ( Expression schema relation grouping params (nullity ('PGcomposite fields))

412− -> Expression schema relation grouping params ('Null ty) ) where

413− fromLabel expr = UnsafeExpression $

414− parenthesized (renderExpression expr) <> "." <>

415− fromString (symbolVal (Proxy @field))

416−

417−instance Semigroup

418− (Expression schema relations grouping params (nullity ('PGvararray ty))) where

419− (<>) = unsafeBinaryOp "||"

420−

421−instance Monoid

422− (Expression schema relations grouping params (nullity ('PGvararray ty))) where

423− mempty = array []

424− mappend = (<>)

425−

426−-- | >>> let expr = greatest currentTimestamp [param @1] :: Expression sch rels grp '[ 'NotNull 'PGtimestamptz] ('NotNull 'PGtimestamptz)

427−-- >>> printSQL expr

428−-- GREATEST(CURRENT_TIMESTAMP, ($1 :: timestamp with time zone))

429−greatest

430− :: Expression schema relations grouping params (nullty)

431− -- ^ needs at least 1 argument

432− -> [Expression schema relations grouping params (nullty)]

433− -- ^ or more

434− -> Expression schema relations grouping params (nullty)

435−greatest x xs = UnsafeExpression $ "GREATEST("

436− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

437−

438−-- | >>> printSQL $ least currentTimestamp [null_]

439−-- LEAST(CURRENT_TIMESTAMP, NULL)

440−least

441− :: Expression schema relations grouping params (nullty)

442− -- ^ needs at least 1 argument

443− -> [Expression schema relations grouping params (nullty)]

444− -- ^ or more

445− -> Expression schema relations grouping params (nullty)

446−least x xs = UnsafeExpression $ "LEAST("

447− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

448

314

449-- | >>> printSQL $ unsafeBinaryOp "OR" true false

315-- | >>> printSQL $ unsafeBinaryOp "OR" true false

450-- (TRUE OR FALSE)

316-- (TRUE OR FALSE)

451−unsafeBinaryOp

317+unsafeBinaryOp :: ByteString -> Operator ty0 ty1 ty2

452− :: ByteString

453− -- ^ operator

454− -> Expression schema relations grouping params (ty0)

455− -> Expression schema relations grouping params (ty1)

456− -> Expression schema relations grouping params (ty2)

457unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

318unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

458− renderExpression x <+> op <+> renderExpression y

319+ renderSQL x <+> op <+> renderSQL y

459

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

327+

460−-- | >>> printSQL $ unsafeUnaryOp "NOT" true

328+-- | >>> printSQL $ unsafeLeftOp "NOT" true

461-- (NOT TRUE)

329-- (NOT TRUE)

462−unsafeUnaryOp

463− :: ByteString

330+unsafeLeftOp :: ByteString -> x --> y

464− -- ^ operator

331+unsafeLeftOp op x = UnsafeExpression $ parenthesized $ op <+> renderSQL x

465− -> Expression schema relations grouping params (ty0)

332+

466− -> Expression schema relations grouping params (ty1)

333+leftOp

334+ :: forall op sch schemas schema x y.

335+ ( Has sch schemas schema

336+ , Has op schema ('Operator ('LeftOp x y)) )

337+ => FunctionDB schemas x y

338+leftOp = unsafeLeftOp $ renderSymbol @op

339+

340+-- | >>> printSQL $ true & unsafeRightOp "IS NOT TRUE"

341+-- (TRUE IS NOT TRUE)

342+unsafeRightOp :: ByteString -> x --> y

467−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $

343+unsafeRightOp op x = UnsafeExpression $ parenthesized $ renderSQL x <+> op

468− op <+> renderExpression x

344+

345+rightOp

346+ :: forall op sch schemas schema x y.

347+ ( Has sch schemas schema

348+ , Has op schema ('Operator ('RightOp x y)) )

349+ => FunctionDB schemas x y

350+rightOp = unsafeRightOp $ renderSymbol @op

469

351

470-- | >>> printSQL $ unsafeFunction "f" true

352-- | >>> printSQL $ unsafeFunction "f" true

471-- f(TRUE)

353-- f(TRUE)

472−unsafeFunction

354+unsafeFunction :: ByteString -> x --> y

473− :: ByteString

474− -- ^ function

475− -> Expression schema relations grouping params (xty)

476− -> Expression schema relations grouping params (yty)

477unsafeFunction fun x = UnsafeExpression $

355unsafeFunction fun x = UnsafeExpression $

478− fun <> parenthesized (renderExpression x)

356+ fun <> parenthesized (renderSQL x)

479−

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+

480−instance PGNum ty

378+instance ty `In` PGNum

481− => Num (Expression schema relations grouping params (nullity ty)) where

379+ => Num (Expression outer commons grp schemas params from (null ty)) where

482 (+) = unsafeBinaryOp "+"

380 (+) = unsafeBinaryOp "+"

483 (-) = unsafeBinaryOp "-"

381 (-) = unsafeBinaryOp "-"

484 (*) = unsafeBinaryOp "*"

382 (*) = unsafeBinaryOp "*"

@@ -489,19 +387,24 @@ instance PGNum ty

489 . fromString

387 . fromString

490 . show

388 . show

491

389

492−instance (PGNum ty, PGFloating ty) => Fractional

390+instance (ty `In` PGNum, ty `In` PGFloating) => Fractional

493− (Expression schema relations grouping params (nullity ty)) where

391+ (Expression outer commons grp schemas params from (null ty)) where

494 (/) = unsafeBinaryOp "/"

392 (/) = unsafeBinaryOp "/"

495− fromRational x = fromInteger (numerator x) / fromInteger (denominator x)

393+ fromRational

394+ = UnsafeExpression

395+ . fromString

396+ . ($ "")

397+ . showFFloat Nothing

398+ . fromRat @Double

496

399

497−instance (PGNum ty, PGFloating ty) => Floating

400+instance (ty `In` PGNum, ty `In` PGFloating) => Floating

498− (Expression schema relations grouping params (nullity ty)) where

401+ (Expression outer commons grp schemas params from (null ty)) where

499 pi = UnsafeExpression "pi()"

402 pi = UnsafeExpression "pi()"

500 exp = unsafeFunction "exp"

403 exp = unsafeFunction "exp"

501 log = unsafeFunction "ln"

404 log = unsafeFunction "ln"

502 sqrt = unsafeFunction "sqrt"

405 sqrt = unsafeFunction "sqrt"

503 b ** x = UnsafeExpression $

406 b ** x = UnsafeExpression $

504− "power(" <> renderExpression b <> ", " <> renderExpression x <> ")"

407+ "power(" <> renderSQL b <> ", " <> renderSQL x <> ")"

505 logBase b y = log y / log b

408 logBase b y = log y / log b

506 sin = unsafeFunction "sin"

409 sin = unsafeFunction "sin"

507 cos = unsafeFunction "cos"

410 cos = unsafeFunction "cos"

@@ -516,735 +419,54 @@ instance (PGNum ty, PGFloating ty) => Floating

516 acosh x = log (x + sqrt (x*x - 1))

419 acosh x = log (x + sqrt (x*x - 1))

517 atanh x = log ((1 + x) / (1 - x)) / 2

420 atanh x = log ((1 + x) / (1 - x)) / 2

518

421

519−-- | >>> :{

422+-- | Contained by operators

520−-- let

423+class PGSubset ty where

521−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

424+ (@>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

522−-- expression = atan2_ pi 2

425+ (@>) = unsafeBinaryOp "@>"

523−-- in printSQL expression

426+ (<@) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

524−-- :}

427+ (<@) = unsafeBinaryOp "<@"

525−-- atan2(pi(), 2)

428+instance PGSubset 'PGjsonb

526−atan2_

429+instance PGSubset 'PGtsquery

527− :: PGFloating float

430+instance PGSubset ('PGvararray ty)

528− => Expression schema relations grouping params (nullity float)

431+instance PGSubset ('PGrange ty)

529− -- ^ numerator

432+

530− -> Expression schema relations grouping params (nullity float)

433+class PGIntersect ty where

531− -- ^ denominator

434+ (@&&) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

532− -> Expression schema relations grouping params (nullity float)

435+ (@&&) = unsafeBinaryOp "&&"

533−atan2_ y x = UnsafeExpression $

436+instance PGIntersect ('PGvararray ty)

534− "atan2(" <> renderExpression y <> ", " <> renderExpression x <> ")"

437+instance PGIntersect ('PGrange ty)

535−

536−-- When a `cast` is applied to an `Expression` of a known type, it

537−-- represents a run-time type conversion. The cast will succeed only if a

538−-- suitable type conversion operation has been defined.

539−--

540−-- | >>> printSQL $ true & cast int4

541−-- (TRUE :: int4)

542−cast

543− :: TypeExpression schema ty1

544− -- ^ type to cast as

545− -> Expression schema relations grouping params (nullity ty0)

546− -- ^ value to convert

547− -> Expression schema relations grouping params (nullity ty1)

548−cast ty x = UnsafeExpression $ parenthesized $

549− renderExpression x <+> "::" <+> renderTypeExpression ty

550−

551−-- | integer division, truncates the result

552−--

553−-- >>> :{

554−-- let

555−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

556−-- expression = 5 `quot_` 2

557−-- in printSQL expression

558−-- :}

559−-- (5 / 2)

560−quot_

561− :: PGIntegral int

562− => Expression schema relations grouping params (nullity int)

563− -- ^ numerator

564− -> Expression schema relations grouping params (nullity int)

565− -- ^ denominator

566− -> Expression schema relations grouping params (nullity int)

567−quot_ = unsafeBinaryOp "/"

568−

569−-- | remainder upon integer division

570−--

571−-- >>> :{

572−-- let

573−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

574−-- expression = 5 `rem_` 2

575−-- in printSQL expression

576−-- :}

577−-- (5 % 2)

578−rem_

579− :: PGIntegral int

580− => Expression schema relations grouping params (nullity int)

581− -- ^ numerator

582− -> Expression schema relations grouping params (nullity int)

583− -- ^ denominator

584− -> Expression schema relations grouping params (nullity int)

585−rem_ = unsafeBinaryOp "%"

586−

587−-- | >>> :{

588−-- let

589−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

590−-- expression = trunc pi

591−-- in printSQL expression

592−-- :}

593−-- trunc(pi())

594−trunc

595− :: PGFloating frac

596− => Expression schema relations grouping params (nullity frac)

597− -- ^ fractional number

598− -> Expression schema relations grouping params (nullity frac)

599−trunc = unsafeFunction "trunc"

600−

601−-- | >>> :{

602−-- let

603−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

604−-- expression = round_ pi

605−-- in printSQL expression

606−-- :}

607−-- round(pi())

608−round_

609− :: PGFloating frac

610− => Expression schema relations grouping params (nullity frac)

611− -- ^ fractional number

612− -> Expression schema relations grouping params (nullity frac)

613−round_ = unsafeFunction "round"

614−

615−-- | >>> :{

616−-- let

617−-- expression :: Expression schema relations grouping params (nullity 'PGfloat4)

618−-- expression = ceiling_ pi

619−-- in printSQL expression

620−-- :}

621−-- ceiling(pi())

622−ceiling_

623− :: PGFloating frac

624− => Expression schema relations grouping params (nullity frac)

625− -- ^ fractional number

626− -> Expression schema relations grouping params (nullity frac)

627−ceiling_ = unsafeFunction "ceiling"

628−

629−-- | A `Condition` is a boolean valued `Expression`. While SQL allows

630−-- conditions to have @NULL@, Squeal instead chooses to disallow @NULL@,

631−-- forcing one to handle the case of @NULL@ explicitly to produce

632−-- a `Condition`.

633−type Condition schema relations grouping params =

634− Expression schema relations grouping params ('NotNull 'PGbool)

635−

636−-- | >>> printSQL true

637−-- TRUE

638−true :: Condition schema relations grouping params

639−true = UnsafeExpression "TRUE"

640−

641−-- | >>> printSQL false

642−-- FALSE

643−false :: Condition schema relations grouping params

644−false = UnsafeExpression "FALSE"

645−

646−-- | >>> printSQL $ not_ true

647−-- (NOT TRUE)

648−not_

649− :: Condition schema relations grouping params

650− -> Condition schema relations grouping params

651−not_ = unsafeUnaryOp "NOT"

652−

653−-- | >>> printSQL $ true .&& false

654−-- (TRUE AND FALSE)

655−(.&&)

656− :: Condition schema relations grouping params

657− -> Condition schema relations grouping params

658− -> Condition schema relations grouping params

659−(.&&) = unsafeBinaryOp "AND"

660−

661−-- | >>> printSQL $ true .|| false

662−-- (TRUE OR FALSE)

663−(.||)

664− :: Condition schema relations grouping params

665− -> Condition schema relations grouping params

666− -> Condition schema relations grouping params

667−(.||) = unsafeBinaryOp "OR"

668−

669−-- | >>> :{

670−-- let

671−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

672−-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3

673−-- in printSQL expression

674−-- :}

675−-- CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END

676−caseWhenThenElse

677− :: [ ( Condition schema relations grouping params

678− , Expression schema relations grouping params (ty)

679− ) ]

680− -- ^ whens and thens

681− -> Expression schema relations grouping params (ty)

682− -- ^ else

683− -> Expression schema relations grouping params (ty)

684−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat

685− [ "CASE"

686− , mconcat

687− [ mconcat

688− [ " WHEN ", renderExpression when_

689− , " THEN ", renderExpression then_

690− ]

691− | (when_,then_) <- whenThens

692− ]

693− , " ELSE ", renderExpression else_

694− , " END"

695− ]

696−

697−-- | >>> :{

698−-- let

699−-- expression :: Expression schema relations grouping params (nullity 'PGint2)

700−-- expression = ifThenElse true 1 0

701−-- in printSQL expression

702−-- :}

703−-- CASE WHEN TRUE THEN 1 ELSE 0 END

704−ifThenElse

705− :: Condition schema relations grouping params

706− -> Expression schema relations grouping params (ty) -- ^ then

707− -> Expression schema relations grouping params (ty) -- ^ else

708− -> Expression schema relations grouping params (ty)

709−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_

710−

711−-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`

712−-- will produce @NULL@s if one of their arguments is @NULL@.

713−--

714−-- >>> printSQL $ notNull true .== null_

715−-- (TRUE = NULL)

716−(.==)

717− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

718− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

719− -> Expression schema relations grouping params (nullity 'PGbool)

720−(.==) = unsafeBinaryOp "="

721−infix 4 .==

722−

723−-- | >>> printSQL $ notNull true ./= null_

724−-- (TRUE <> NULL)

725−(./=)

726− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

727− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

728− -> Expression schema relations grouping params (nullity 'PGbool)

729−(./=) = unsafeBinaryOp "<>"

730−infix 4 ./=

731−

732−-- | >>> printSQL $ notNull true .>= null_

733−-- (TRUE >= NULL)

734−(.>=)

735− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

736− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

737− -> Expression schema relations grouping params (nullity 'PGbool)

738−(.>=) = unsafeBinaryOp ">="

739−infix 4 .>=

740−

741−-- | >>> printSQL $ notNull true .< null_

742−-- (TRUE < NULL)

743−(.<)

744− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

745− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

746− -> Expression schema relations grouping params (nullity 'PGbool)

747−(.<) = unsafeBinaryOp "<"

748−infix 4 .<

749−

750−-- | >>> printSQL $ notNull true .<= null_

751−-- (TRUE <= NULL)

752−(.<=)

753− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

754− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

755− -> Expression schema relations grouping params (nullity 'PGbool)

756−(.<=) = unsafeBinaryOp "<="

757−infix 4 .<=

758−

759−-- | >>> printSQL $ notNull true .> null_

760−-- (TRUE > NULL)

761−(.>)

762− :: Expression schema relations grouping params (nullity ty) -- ^ lhs

763− -> Expression schema relations grouping params (nullity ty) -- ^ rhs

764− -> Expression schema relations grouping params (nullity 'PGbool)

765−(.>) = unsafeBinaryOp ">"

766−infix 4 .>

767−

768−-- | >>> printSQL currentDate

769−-- CURRENT_DATE

770−currentDate

771− :: Expression schema relations grouping params (nullity 'PGdate)

772−currentDate = UnsafeExpression "CURRENT_DATE"

773−

774−-- | >>> printSQL currentTime

775−-- CURRENT_TIME

776−currentTime

777− :: Expression schema relations grouping params (nullity 'PGtimetz)

778−currentTime = UnsafeExpression "CURRENT_TIME"

779−

780−-- | >>> printSQL currentTimestamp

781−-- CURRENT_TIMESTAMP

782−currentTimestamp

783− :: Expression schema relations grouping params (nullity 'PGtimestamptz)

784−currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"

785−

786−-- | >>> printSQL localTime

787−-- LOCALTIME

788−localTime

789− :: Expression schema relations grouping params (nullity 'PGtime)

790−localTime = UnsafeExpression "LOCALTIME"

791−

792−-- | >>> printSQL localTimestamp

793−-- LOCALTIMESTAMP

794−localTimestamp

795− :: Expression schema relations grouping params (nullity 'PGtimestamp)

796−localTimestamp = UnsafeExpression "LOCALTIMESTAMP"

797−

798−{-----------------------------------------

799−text

800−-----------------------------------------}

801

438

802instance IsString

439instance IsString

803− (Expression schema relations grouping params (nullity 'PGtext)) where

440+ (Expression outer commons grp schemas params from (null 'PGtext)) where

804 fromString str = UnsafeExpression $

441 fromString str = UnsafeExpression $

805 "E\'" <> fromString (escape =<< str) <> "\'"

442 "E\'" <> fromString (escape =<< str) <> "\'"

806− where

443+instance IsString

807− escape = \case

444+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

808− '\NUL' -> "\\0"

445+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsvector") $

809− '\'' -> "''"

446+ "E\'" <> fromString (escape =<< str) <> "\'"

810− '"' -> "\\\""

447+instance IsString

811− '\b' -> "\\b"

448+ (Expression outer commons grp schemas params from (null 'PGtsquery)) where

812− '\n' -> "\\n"

449+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsquery") $

813− '\r' -> "\\r"

450+ "E\'" <> fromString (escape =<< str) <> "\'"

814− '\t' -> "\\t"

815− '\\' -> "\\\\"

816− c -> [c]

817

451

818instance Semigroup

452instance Semigroup

819− (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

820 (<>) = unsafeBinaryOp "||"

463 (<>) = unsafeBinaryOp "||"

821

464

822instance Monoid

465instance Monoid

823− (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

824 mempty = fromString ""

471 mempty = fromString ""

825 mappend = (<>)

472 mappend = (<>)

826−

827−-- | >>> printSQL $ lower "ARRRGGG"

828−-- lower(E'ARRRGGG')

829−lower

830− :: Expression schema relations grouping params (nullity 'PGtext)

831− -- ^ string to lower case

832− -> Expression schema relations grouping params (nullity 'PGtext)

833−lower = unsafeFunction "lower"

834−

835−-- | >>> printSQL $ upper "eeee"

836−-- upper(E'eeee')

837−upper

838− :: Expression schema relations grouping params (nullity 'PGtext)

839− -- ^ string to upper case

840− -> Expression schema relations grouping params (nullity 'PGtext)

841−upper = unsafeFunction "upper"

842−

843−-- | >>> printSQL $ charLength "four"

844−-- char_length(E'four')

845−charLength

846− :: Expression schema relations grouping params (nullity 'PGtext)

847− -- ^ string to measure

848− -> Expression schema relations grouping params (nullity 'PGint4)

849−charLength = unsafeFunction "char_length"

850−

851−-- | The `like` expression returns true if the @string@ matches

852−-- the supplied @pattern@. If @pattern@ does not contain percent signs

853−-- or underscores, then the pattern only represents the string itself;

854−-- in that case `like` acts like the equals operator. An underscore (_)

855−-- in pattern stands for (matches) any single character; a percent sign (%)

856−-- matches any sequence of zero or more characters.

857−--

858−-- >>> printSQL $ "abc" `like` "a%"

859−-- (E'abc' LIKE E'a%')

860−like

861− :: Expression schema relations grouping params (nullity 'PGtext)

862− -- ^ string

863− -> Expression schema relations grouping params (nullity 'PGtext)

864− -- ^ pattern

865− -> Expression schema relations grouping params (nullity 'PGbool)

866−like = unsafeBinaryOp "LIKE"

867−

868−{-----------------------------------------

869−aggregation

870−-----------------------------------------}

871−

872−-- | escape hatch to define aggregate functions

873−unsafeAggregate

874− :: ByteString -- ^ aggregate function

875− -> Expression schema relations 'Ungrouped params (xty)

876− -> Expression schema relations ('Grouped bys) params (yty)

877−unsafeAggregate fun x = UnsafeExpression $ mconcat

878− [fun, "(", renderExpression x, ")"]

879−

880−-- | escape hatch to define aggregate functions over distinct values

881−unsafeAggregateDistinct

882− :: ByteString -- ^ aggregate function

883− -> Expression schema relations 'Ungrouped params (xty)

884− -> Expression schema relations ('Grouped bys) params (yty)

885−unsafeAggregateDistinct fun x = UnsafeExpression $ mconcat

886− [fun, "(DISTINCT ", renderExpression x, ")"]

887−

888−-- | >>> :{

889−-- let

890−-- expression :: Expression schema '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Grouped bys) params ('Null 'PGnumeric)

891−-- expression = sum_ #col

892−-- in printSQL expression

893−-- :}

894−-- sum("col")

895−sum_

896− :: PGNum ty

897− => Expression schema relations 'Ungrouped params (nullity ty)

898− -- ^ what to sum

899− -> Expression schema relations ('Grouped bys) params (nullity ty)

900−sum_ = unsafeAggregate "sum"

901−

902−-- | >>> :{

903−-- let

904−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGnumeric]] ('Grouped bys) params (nullity 'PGnumeric)

905−-- expression = sumDistinct #col

906−-- in printSQL expression

907−-- :}

908−-- sum(DISTINCT "col")

909−sumDistinct

910− :: PGNum ty

911− => Expression schema relations 'Ungrouped params (nullity ty)

912− -- ^ what to sum

913− -> Expression schema relations ('Grouped bys) params (nullity ty)

914−sumDistinct = unsafeAggregateDistinct "sum"

915−

916−-- | A constraint for `PGType`s that you can take averages of and the resulting

917−-- `PGType`.

918−class PGAvg ty avg | ty -> avg where

919− avg, avgDistinct

920− :: Expression schema relations 'Ungrouped params (nullity ty)

921− -- ^ what to average

922− -> Expression schema relations ('Grouped bys) params (nullity avg)

923− avg = unsafeAggregate "avg"

924− avgDistinct = unsafeAggregateDistinct "avg"

925−instance PGAvg 'PGint2 'PGnumeric

926−instance PGAvg 'PGint4 'PGnumeric

927−instance PGAvg 'PGint8 'PGnumeric

928−instance PGAvg 'PGnumeric 'PGnumeric

929−instance PGAvg 'PGfloat4 'PGfloat8

930−instance PGAvg 'PGfloat8 'PGfloat8

931−instance PGAvg 'PGinterval 'PGinterval

932−

933−-- | >>> :{

934−-- let

935−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

936−-- expression = bitAnd #col

937−-- in printSQL expression

938−-- :}

939−-- bit_and("col")

940−bitAnd

941− :: PGIntegral int

942− => Expression schema relations 'Ungrouped params (nullity int)

943− -- ^ what to aggregate

944− -> Expression schema relations ('Grouped bys) params (nullity int)

945−bitAnd = unsafeAggregate "bit_and"

946−

947−-- | >>> :{

948−-- let

949−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

950−-- expression = bitOr #col

951−-- in printSQL expression

952−-- :}

953−-- bit_or("col")

954−bitOr

955− :: PGIntegral int

956− => Expression schema relations 'Ungrouped params (nullity int)

957− -- ^ what to aggregate

958− -> Expression schema relations ('Grouped bys) params (nullity int)

959−bitOr = unsafeAggregate "bit_or"

960−

961−-- | >>> :{

962−-- let

963−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

964−-- expression = bitAndDistinct #col

965−-- in printSQL expression

966−-- :}

967−-- bit_and(DISTINCT "col")

968−bitAndDistinct

969− :: PGIntegral int

970− => Expression schema relations 'Ungrouped params (nullity int)

971− -- ^ what to aggregate

972− -> Expression schema relations ('Grouped bys) params (nullity int)

973−bitAndDistinct = unsafeAggregateDistinct "bit_and"

974−

975−-- | >>> :{

976−-- let

977−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

978−-- expression = bitOrDistinct #col

979−-- in printSQL expression

980−-- :}

981−-- bit_or(DISTINCT "col")

982−bitOrDistinct

983− :: PGIntegral int

984− => Expression schema relations 'Ungrouped params (nullity int)

985− -- ^ what to aggregate

986− -> Expression schema relations ('Grouped bys) params (nullity int)

987−bitOrDistinct = unsafeAggregateDistinct "bit_or"

988−

989−-- | >>> :{

990−-- let

991−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

992−-- expression = boolAnd #col

993−-- in printSQL expression

994−-- :}

995−-- bool_and("col")

996−boolAnd

997− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

998− -- ^ what to aggregate

999− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1000−boolAnd = unsafeAggregate "bool_and"

1001−

1002−-- | >>> :{

1003−-- let

1004−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1005−-- expression = boolOr #col

1006−-- in printSQL expression

1007−-- :}

1008−-- bool_or("col")

1009−boolOr

1010− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1011− -- ^ what to aggregate

1012− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1013−boolOr = unsafeAggregate "bool_or"

1014−

1015−-- | >>> :{

1016−-- let

1017−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1018−-- expression = boolAndDistinct #col

1019−-- in printSQL expression

1020−-- :}

1021−-- bool_and(DISTINCT "col")

1022−boolAndDistinct

1023− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1024− -- ^ what to aggregate

1025− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1026−boolAndDistinct = unsafeAggregateDistinct "bool_and"

1027−

1028−-- | >>> :{

1029−-- let

1030−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1031−-- expression = boolOrDistinct #col

1032−-- in printSQL expression

1033−-- :}

1034−-- bool_or(DISTINCT "col")

1035−boolOrDistinct

1036− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1037− -- ^ what to aggregate

1038− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1039−boolOrDistinct = unsafeAggregateDistinct "bool_or"

1040−

1041−-- | A special aggregation that does not require an input

1042−--

1043−-- >>> printSQL countStar

1044−-- count(*)

1045−countStar

1046− :: Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1047−countStar = UnsafeExpression $ "count(*)"

1048−

1049−-- | >>> :{

1050−-- let

1051−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1052−-- expression = count #col

1053−-- in printSQL expression

1054−-- :}

1055−-- count("col")

1056−count

1057− :: Expression schema relations 'Ungrouped params ty

1058− -- ^ what to count

1059− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1060−count = unsafeAggregate "count"

1061−

1062−-- | >>> :{

1063−-- let

1064−-- expression :: Expression schema '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

1065−-- expression = countDistinct #col

1066−-- in printSQL expression

1067−-- :}

1068−-- count(DISTINCT "col")

1069−countDistinct

1070− :: Expression schema relations 'Ungrouped params ty

1071− -- ^ what to count

1072− -> Expression schema relations ('Grouped bys) params ('NotNull 'PGint8)

1073−countDistinct = unsafeAggregateDistinct "count"

1074−

1075−-- | synonym for `boolAnd`

1076−--

1077−-- >>> :{

1078−-- let

1079−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1080−-- expression = every #col

1081−-- in printSQL expression

1082−-- :}

1083−-- every("col")

1084−every

1085− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1086− -- ^ what to aggregate

1087− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1088−every = unsafeAggregate "every"

1089−

1090−-- | synonym for `boolAndDistinct`

1091−--

1092−-- >>> :{

1093−-- let

1094−-- expression :: Expression schema '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

1095−-- expression = everyDistinct #col

1096−-- in printSQL expression

1097−-- :}

1098−-- every(DISTINCT "col")

1099−everyDistinct

1100− :: Expression schema relations 'Ungrouped params (nullity 'PGbool)

1101− -- ^ what to aggregate

1102− -> Expression schema relations ('Grouped bys) params (nullity 'PGbool)

1103−everyDistinct = unsafeAggregateDistinct "every"

1104−

1105−-- | minimum and maximum aggregation

1106−max_, min_, maxDistinct, minDistinct

1107− :: Expression schema relations 'Ungrouped params (nullity ty)

1108− -- ^ what to aggregate

1109− -> Expression schema relations ('Grouped bys) params (nullity ty)

1110−max_ = unsafeAggregate "max"

1111−min_ = unsafeAggregate "min"

1112−maxDistinct = unsafeAggregateDistinct "max"

1113−minDistinct = unsafeAggregateDistinct "min"

1114−

1115−{-----------------------------------------

1116−type expressions

1117−-----------------------------------------}

1118−

1119−-- | `TypeExpression`s are used in `cast`s and `createTable` commands.

1120−newtype TypeExpression (schema :: SchemaType) (ty :: PGType)

1121− = UnsafeTypeExpression { renderTypeExpression :: ByteString }

1122− deriving (GHC.Generic,Show,Eq,Ord,NFData)

1123−

1124−instance (Has alias schema ('Typedef ty))

1125− => IsLabel alias (TypeExpression schema ty) where

1126− fromLabel = UnsafeTypeExpression (renderAlias (fromLabel @alias))

1127−

1128−-- | logical Boolean (true/false)

1129−bool :: TypeExpression schema 'PGbool

1130−bool = UnsafeTypeExpression "bool"

1131−-- | signed two-byte integer

1132−int2, smallint :: TypeExpression schema 'PGint2

1133−int2 = UnsafeTypeExpression "int2"

1134−smallint = UnsafeTypeExpression "smallint"

1135−-- | signed four-byte integer

1136−int4, int, integer :: TypeExpression schema 'PGint4

1137−int4 = UnsafeTypeExpression "int4"

1138−int = UnsafeTypeExpression "int"

1139−integer = UnsafeTypeExpression "integer"

1140−-- | signed eight-byte integer

1141−int8, bigint :: TypeExpression schema 'PGint8

1142−int8 = UnsafeTypeExpression "int8"

1143−bigint = UnsafeTypeExpression "bigint"

1144−-- | arbitrary precision numeric type

1145−numeric :: TypeExpression schema 'PGnumeric

1146−numeric = UnsafeTypeExpression "numeric"

1147−-- | single precision floating-point number (4 bytes)

1148−float4, real :: TypeExpression schema 'PGfloat4

1149−float4 = UnsafeTypeExpression "float4"

1150−real = UnsafeTypeExpression "real"

1151−-- | double precision floating-point number (8 bytes)

1152−float8, doublePrecision :: TypeExpression schema 'PGfloat8

1153−float8 = UnsafeTypeExpression "float8"

1154−doublePrecision = UnsafeTypeExpression "double precision"

1155−-- | variable-length character string

1156−text :: TypeExpression schema 'PGtext

1157−text = UnsafeTypeExpression "text"

1158−-- | fixed-length character string

1159−char, character

1160− :: (KnownNat n, 1 <= n)

1161− => proxy n

1162− -> TypeExpression schema ('PGchar n)

1163−char p = UnsafeTypeExpression $ "char(" <> renderNat p <> ")"

1164−character p = UnsafeTypeExpression $ "character(" <> renderNat p <> ")"

1165−-- | variable-length character string

1166−varchar, characterVarying

1167− :: (KnownNat n, 1 <= n)

1168− => proxy n

1169− -> TypeExpression schema ('PGvarchar n)

1170−varchar p = UnsafeTypeExpression $ "varchar(" <> renderNat p <> ")"

1171−characterVarying p = UnsafeTypeExpression $

1172− "character varying(" <> renderNat p <> ")"

1173−-- | binary data ("byte array")

1174−bytea :: TypeExpression schema 'PGbytea

1175−bytea = UnsafeTypeExpression "bytea"

1176−-- | date and time (no time zone)

1177−timestamp :: TypeExpression schema 'PGtimestamp

1178−timestamp = UnsafeTypeExpression "timestamp"

1179−-- | date and time, including time zone

1180−timestampWithTimeZone :: TypeExpression schema 'PGtimestamptz

1181−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"

1182−-- | calendar date (year, month, day)

1183−date :: TypeExpression schema 'PGdate

1184−date = UnsafeTypeExpression "date"

1185−-- | time of day (no time zone)

1186−time :: TypeExpression schema 'PGtime

1187−time = UnsafeTypeExpression "time"

1188−-- | time of day, including time zone

1189−timeWithTimeZone :: TypeExpression schema 'PGtimetz

1190−timeWithTimeZone = UnsafeTypeExpression "time with time zone"

1191−-- | time span

1192−interval :: TypeExpression schema 'PGinterval

1193−interval = UnsafeTypeExpression "interval"

1194−-- | universally unique identifier

1195−uuid :: TypeExpression schema 'PGuuid

1196−uuid = UnsafeTypeExpression "uuid"

1197−-- | IPv4 or IPv6 host address

1198−inet :: TypeExpression schema 'PGinet

1199−inet = UnsafeTypeExpression "inet"

1200−-- | textual JSON data

1201−json :: TypeExpression schema 'PGjson

1202−json = UnsafeTypeExpression "json"

1203−-- | binary JSON data, decomposed

1204−jsonb :: TypeExpression schema 'PGjsonb

1205−jsonb = UnsafeTypeExpression "jsonb"

1206−-- | variable length array

1207−vararray

1208− :: TypeExpression schema pg

1209− -> TypeExpression schema ('PGvararray pg)

1210−vararray ty = UnsafeTypeExpression $ renderTypeExpression ty <> "[]"

1211−-- | fixed length array

1212−--

1213−-- >>> renderTypeExpression (fixarray (Proxy @2) json)

1214−-- "json[2]"

1215−fixarray

1216− :: KnownNat n

1217− => proxy n

1218− -> TypeExpression schema pg

1219− -> TypeExpression schema ('PGfixarray n pg)

1220−fixarray p ty = UnsafeTypeExpression $

1221− renderTypeExpression ty <> "[" <> renderNat p <> "]"

1222−

1223−-- | `pgtype` is a demoted version of a `PGType`

1224−class PGTyped schema (ty :: PGType) where pgtype :: TypeExpression schema ty

1225−instance PGTyped schema 'PGbool where pgtype = bool

1226−instance PGTyped schema 'PGint2 where pgtype = int2

1227−instance PGTyped schema 'PGint4 where pgtype = int4

1228−instance PGTyped schema 'PGint8 where pgtype = int8

1229−instance PGTyped schema 'PGnumeric where pgtype = numeric

1230−instance PGTyped schema 'PGfloat4 where pgtype = float4

1231−instance PGTyped schema 'PGfloat8 where pgtype = float8

1232−instance PGTyped schema 'PGtext where pgtype = text

1233−instance (KnownNat n, 1 <= n)

1234− => PGTyped schema ('PGchar n) where pgtype = char (Proxy @n)

1235−instance (KnownNat n, 1 <= n)

1236− => PGTyped schema ('PGvarchar n) where pgtype = varchar (Proxy @n)

1237−instance PGTyped schema 'PGbytea where pgtype = bytea

1238−instance PGTyped schema 'PGtimestamp where pgtype = timestamp

1239−instance PGTyped schema 'PGtimestamptz where pgtype = timestampWithTimeZone

1240−instance PGTyped schema 'PGdate where pgtype = date

1241−instance PGTyped schema 'PGtime where pgtype = time

1242−instance PGTyped schema 'PGtimetz where pgtype = timeWithTimeZone

1243−instance PGTyped schema 'PGinterval where pgtype = interval

1244−instance PGTyped schema 'PGuuid where pgtype = uuid

1245−instance PGTyped schema 'PGjson where pgtype = json

1246−instance PGTyped schema 'PGjsonb where pgtype = jsonb

1247−instance PGTyped schema ty => PGTyped schema ('PGvararray ty) where

1248− pgtype = vararray (pgtype @schema @ty)

1249−instance (KnownNat n, PGTyped schema ty) => PGTyped schema ('PGfixarray n ty) where

1250− pgtype = fixarray (Proxy @n) (pgtype @schema @ty)

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Aggregate.hsnew file+462

@@ -0,0 +1,462 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Aggregate

3+Description: Aggregate functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Aggregate functions

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , DeriveGeneric

14+ , FlexibleContexts

15+ , FlexibleInstances

16+ , FunctionalDependencies

17+ , LambdaCase

18+ , MultiParamTypeClasses

19+ , OverloadedStrings

20+ , PolyKinds

21+ , TypeFamilies

22+ , TypeOperators

23+ , UndecidableInstances

24+#-}

25+

26+module Squeal.PostgreSQL.Expression.Aggregate

27+ ( Aggregate (..)

28+ , Distinction (..)

29+ , PGSum

30+ , PGAvg

31+ ) where

32+

33+import Control.DeepSeq

34+import Data.ByteString (ByteString)

35+import Data.Kind

36+import GHC.TypeLits

37+

38+import qualified GHC.Generics as GHC

39+import qualified Generics.SOP as SOP

40+

41+import Squeal.PostgreSQL.Alias

42+import Squeal.PostgreSQL.Expression

43+import Squeal.PostgreSQL.List

44+import Squeal.PostgreSQL.Render

45+import Squeal.PostgreSQL.Schema

46+

47+-- $setup

48+-- >>> import Squeal.PostgreSQL

49+

50+{- |

51+`Aggregate` functions compute a single result from a set of input values.

52+`Aggregate` functions can be used as `GroupedBy` `Expression`s as well

53+as `Squeal.PostgreSQL.Expression.Window.WindowFunction`s.

54+-}

55+class Aggregate expr1 exprN aggr

56+ | aggr -> expr1, aggr -> exprN where

57+

58+ -- | A special aggregation that does not require an input

59+ --

60+ -- >>> :{

61+ -- let

62+ -- expression :: Expression '[] commons ('Grouped bys) schemas params from ('NotNull 'PGint8)

63+ -- expression = countStar

64+ -- in printSQL expression

65+ -- :}

66+ -- count(*)

67+ countStar :: aggr ('NotNull 'PGint8)

68+

69+ -- | >>> :{

70+ -- let

71+ -- expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null ty]] ('NotNull 'PGint8)

72+ -- expression = count (All #col)

73+ -- in printSQL expression

74+ -- :}

75+ -- count(ALL "col")

76+ count

77+ :: expr1 ty

78+ -- ^ what to count

79+ -> aggr ('NotNull 'PGint8)

80+

81+ -- | >>> :{

82+ -- let

83+ -- expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Null 'PGnumeric)

84+ -- expression = sum_ (Distinct #col)

85+ -- in printSQL expression

86+ -- :}

87+ -- sum(DISTINCT "col")

88+ sum_

89+ :: expr1 (null ty)

90+ -> aggr ('Null (PGSum ty))

91+

92+ -- | input values, including nulls, concatenated into an array

93+ arrayAgg

94+ :: expr1 ty

95+ -> aggr ('Null ('PGvararray ty))

96+

97+ -- | aggregates values as a JSON array

98+ jsonAgg

99+ :: expr1 ty

100+ -> aggr ('Null 'PGjson)

101+

102+ -- | aggregates values as a JSON array

103+ jsonbAgg

104+ :: expr1 ty

105+ -> aggr ('Null 'PGjsonb)

106+

107+ {- |

108+ the bitwise AND of all non-null input values, or null if none

109+

110+ >>> :{

111+ let

112+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGint4]] ('Null 'PGint4)

113+ expression = bitAnd (Distinct #col)

114+ in printSQL expression

115+ :}

116+ bit_and(DISTINCT "col")

117+ -}

118+ bitAnd

119+ :: int `In` PGIntegral

120+ => expr1 (null int)

121+ -- ^ what to aggregate

122+ -> aggr ('Null int)

123+

124+ {- |

125+ the bitwise OR of all non-null input values, or null if none

126+

127+ >>> :{

128+ let

129+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGint4]] ('Null 'PGint4)

130+ expression = bitOr (All #col)

131+ in printSQL expression

132+ :}

133+ bit_or(ALL "col")

134+ -}

135+ bitOr

136+ :: int `In` PGIntegral

137+ => expr1 (null int)

138+ -- ^ what to aggregate

139+ -> aggr ('Null int)

140+

141+ {- |

142+ true if all input values are true, otherwise false

143+

144+ >>> :{

145+ let

146+ winFun :: WindowFunction '[] commons 'Ungrouped schemas params '[tab ::: '["col" ::: null 'PGbool]] ('Null 'PGbool)

147+ winFun = boolAnd #col

148+ in printSQL winFun

149+ :}

150+ bool_and("col")

151+ -}

152+ boolAnd

153+ :: expr1 (null 'PGbool)

154+ -- ^ what to aggregate

155+ -> aggr ('Null 'PGbool)

156+

157+ {- |

158+ true if at least one input value is true, otherwise false

159+

160+ >>> :{

161+ let

162+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGbool]] ('Null 'PGbool)

163+ expression = boolOr (All #col)

164+ in printSQL expression

165+ :}

166+ bool_or(ALL "col")

167+ -}

168+ boolOr

169+ :: expr1 (null 'PGbool)

170+ -- ^ what to aggregate

171+ -> aggr ('Null 'PGbool)

172+

173+ {- |

174+ equivalent to `boolAnd`

175+

176+ >>> :{

177+ let

178+ expression :: Expression '[] commons ('Grouped bys) schemas params '[tab ::: '["col" ::: null 'PGbool]] ('Null 'PGbool)

179+ expression = every (Distinct #col)

180+ in printSQL expression

181+ :}

182+ every(DISTINCT "col")

183+ -}

184+ every

185+ :: expr1 (null 'PGbool)

186+ -- ^ what to aggregate

187+ -> aggr ('Null 'PGbool)

188+

189+ {- |maximum value of expression across all input values-}

190+ max_

191+ :: expr1 (null ty)

192+ -- ^ what to maximize

193+ -> aggr ('Null ty)

194+

195+ -- | minimum value of expression across all input values

196+ min_

197+ :: expr1 (null ty)

198+ -- ^ what to minimize

199+ -> aggr ('Null ty)

200+

201+ -- | the average (arithmetic mean) of all input values

202+ avg

203+ :: expr1 (null ty)

204+ -- ^ what to average

205+ -> aggr ('Null (PGAvg ty))

206+

207+ {- | correlation coefficient

208+

209+ >>> :{

210+ let

211+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)

212+ expression = corr (All (#y *: #x))

213+ in printSQL expression

214+ :}

215+ corr(ALL "y", "x")

216+ -}

217+ corr

218+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

219+ -> aggr ('Null 'PGfloat8)

220+

221+ {- | population covariance

222+

223+ >>> :{

224+ let

225+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)

226+ expression = covarPop (All (#y *: #x))

227+ in printSQL expression

228+ :}

229+ covar_pop(ALL "y", "x")

230+ -}

231+ covarPop

232+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

233+ -> aggr ('Null 'PGfloat8)

234+

235+ {- | sample covariance

236+

237+ >>> :{

238+ let

239+ winFun :: WindowFunction '[] c 'Ungrouped s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)

240+ winFun = covarSamp (#y *: #x)

241+ in printSQL winFun

242+ :}

243+ covar_samp("y", "x")

244+ -}

245+ covarSamp

246+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

247+ -> aggr ('Null 'PGfloat8)

248+

249+ {- | average of the independent variable (sum(X)/N)

250+

251+ >>> :{

252+ let

253+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)

254+ expression = regrAvgX (All (#y *: #x))

255+ in printSQL expression

256+ :}

257+ regr_avgx(ALL "y", "x")

258+ -}

259+ regrAvgX

260+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

261+ -> aggr ('Null 'PGfloat8)

262+

263+ {- | average of the dependent variable (sum(Y)/N)

264+

265+ >>> :{

266+ let

267+ winFun :: WindowFunction '[] c 'Ungrouped s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)

268+ winFun = regrAvgY (#y *: #x)

269+ in printSQL winFun

270+ :}

271+ regr_avgy("y", "x")

272+ -}

273+ regrAvgY

274+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

275+ -> aggr ('Null 'PGfloat8)

276+

277+ {- | number of input rows in which both expressions are nonnull

278+

279+ >>> :{

280+ let

281+ winFun :: WindowFunction '[] c 'Ungrouped s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGint8)

282+ winFun = regrCount (#y *: #x)

283+ in printSQL winFun

284+ :}

285+ regr_count("y", "x")

286+ -}

287+ regrCount

288+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

289+ -> aggr ('Null 'PGint8)

290+

291+ {- | y-intercept of the least-squares-fit linear equation determined by the (X, Y) pairs

292+ >>> :{

293+ let

294+ expression :: Expression '[] c ('Grouped g) s p '[t ::: '["x" ::: 'NotNull 'PGfloat8, "y" ::: 'NotNull 'PGfloat8]] ('Null 'PGfloat8)

295+ expression = regrIntercept (All (#y *: #x))

296+ in printSQL expression

297+ :}

298+ regr_intercept(ALL "y", "x")

299+ -}

300+ regrIntercept

301+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

302+ -> aggr ('Null 'PGfloat8)

303+

304+ -- | @regr_r2(Y, X)@, square of the correlation coefficient

305+ regrR2

306+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

307+ -> aggr ('Null 'PGfloat8)

308+

309+ -- | @regr_slope(Y, X)@, slope of the least-squares-fit linear equation

310+ -- determined by the (X, Y) pairs

311+ regrSlope

312+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

313+ -> aggr ('Null 'PGfloat8)

314+

315+ -- | @regr_sxx(Y, X)@, sum(X^2) - sum(X)^2/N

316+ -- (“sum of squares” of the independent variable)

317+ regrSxx

318+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

319+ -> aggr ('Null 'PGfloat8)

320+

321+ -- | @regr_sxy(Y, X)@, sum(X*Y) - sum(X) * sum(Y)/N

322+ -- (“sum of products” of independent times dependent variable)

323+ regrSxy

324+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

325+ -> aggr ('Null 'PGfloat8)

326+

327+ -- | @regr_syy(Y, X)@, sum(Y^2) - sum(Y)^2/N

328+ -- (“sum of squares” of the dependent variable)

329+ regrSyy

330+ :: exprN '[null 'PGfloat8, null 'PGfloat8]

331+ -> aggr ('Null 'PGfloat8)

332+

333+ -- | historical alias for `stddevSamp`

334+ stddev

335+ :: expr1 (null ty)

336+ -> aggr ('Null (PGAvg ty))

337+

338+ -- | population standard deviation of the input values

339+ stddevPop

340+ :: expr1 (null ty)

341+ -> aggr ('Null (PGAvg ty))

342+

343+ -- | sample standard deviation of the input values

344+ stddevSamp

345+ :: expr1 (null ty)

346+ -> aggr ('Null (PGAvg ty))

347+

348+ -- | historical alias for `varSamp`

349+ variance

350+ :: expr1 (null ty)

351+ -> aggr ('Null (PGAvg ty))

352+

353+ -- | population variance of the input values

354+ -- (square of the population standard deviation)

355+ varPop

356+ :: expr1 (null ty)

357+ -> aggr ('Null (PGAvg ty))

358+

359+ -- | sample variance of the input values

360+ -- (square of the sample standard deviation)

361+ varSamp

362+ :: expr1 (null ty)

363+ -> aggr ('Null (PGAvg ty))

364+

365+{- |

366+`Distinction`s are used for the input of `Aggregate` `Expression`s.

367+`All` invokes the aggregate once for each input row.

368+`Distinct` invokes the aggregate once for each distinct value of the expression

369+(or distinct set of values, for multiple expressions) found in the input

370+-}

371+data Distinction (expr :: kind -> Type) (ty :: kind)

372+ = All (expr ty)

373+ | Distinct (expr ty)

374+ deriving (GHC.Generic,Show,Eq,Ord)

375+instance NFData (Distinction (Expression outer commons grp schemas params from) ty)

376+instance RenderSQL (Distinction (Expression outer commons grp schemas params from) ty) where

377+ renderSQL = \case

378+ All x -> "ALL" <+> renderSQL x

379+ Distinct x -> "DISTINCT" <+> renderSQL x

380+instance SOP.SListI tys => RenderSQL

381+ (Distinction (NP (Expression outer commons grp schemas params from)) tys) where

382+ renderSQL = \case

383+ All xs -> "ALL" <+> renderCommaSeparated renderSQL xs

384+ Distinct xs -> "DISTINCT" <+> renderCommaSeparated renderSQL xs

385+

386+instance Aggregate

387+ (Distinction (Expression outer commons 'Ungrouped schemas params from))

388+ (Distinction (NP (Expression outer commons 'Ungrouped schemas params from)))

389+ (Expression outer commons ('Grouped bys) schemas params from) where

390+ countStar = UnsafeExpression "count(*)"

391+ count = unsafeAggregate1 "count"

392+ sum_ = unsafeAggregate1 "sum"

393+ arrayAgg = unsafeAggregate1 "array_agg"

394+ jsonAgg = unsafeAggregate1 "json_agg"

395+ jsonbAgg = unsafeAggregate1 "jsonb_agg"

396+ bitAnd = unsafeAggregate1 "bit_and"

397+ bitOr = unsafeAggregate1 "bit_or"

398+ boolAnd = unsafeAggregate1 "bool_and"

399+ boolOr = unsafeAggregate1 "bool_or"

400+ every = unsafeAggregate1 "every"

401+ max_ = unsafeAggregate1 "max"

402+ min_ = unsafeAggregate1 "min"

403+ avg = unsafeAggregate1 "avg"

404+ corr = unsafeAggregateN "corr"

405+ covarPop = unsafeAggregateN "covar_pop"

406+ covarSamp = unsafeAggregateN "covar_samp"

407+ regrAvgX = unsafeAggregateN "regr_avgx"

408+ regrAvgY = unsafeAggregateN "regr_avgy"

409+ regrCount = unsafeAggregateN "regr_count"

410+ regrIntercept = unsafeAggregateN "regr_intercept"

411+ regrR2 = unsafeAggregateN "regr_r2"

412+ regrSlope = unsafeAggregateN "regr_slope"

413+ regrSxx = unsafeAggregateN "regr_sxx"

414+ regrSxy = unsafeAggregateN "regr_sxy"

415+ regrSyy = unsafeAggregateN "regr_syy"

416+ stddev = unsafeAggregate1 "stddev"

417+ stddevPop = unsafeAggregate1 "stddev_pop"

418+ stddevSamp = unsafeAggregate1 "stddev_samp"

419+ variance = unsafeAggregate1 "variance"

420+ varPop = unsafeAggregate1 "var_pop"

421+ varSamp = unsafeAggregate1 "var_samp"

422+

423+-- | escape hatch to define aggregate functions

424+unsafeAggregate1

425+ :: ByteString -- ^ aggregate function

426+ -> Distinction (Expression outer commons 'Ungrouped schemas params from) x

427+ -> Expression outer commons ('Grouped bys) schemas params from y

428+unsafeAggregate1 fun x = UnsafeExpression $ fun <> parenthesized (renderSQL x)

429+

430+unsafeAggregateN

431+ :: SOP.SListI xs

432+ => ByteString -- ^ function

433+ -> Distinction (NP (Expression outer commons 'Ungrouped schemas params from)) xs

434+ -> Expression outer commons ('Grouped bys) schemas params from y

435+unsafeAggregateN fun xs = UnsafeExpression $ fun <> parenthesized (renderSQL xs)

436+

437+-- | A type family that calculates `PGSum``PGType` of

438+-- a given argument `PGType`.

439+type family PGSum ty where

440+ PGSum 'PGint2 = 'PGint8

441+ PGSum 'PGint4 = 'PGint8

442+ PGSum 'PGint8 = 'PGnumeric

443+ PGSum 'PGfloat4 = 'PGfloat4

444+ PGSum 'PGfloat8 = 'PGfloat8

445+ PGSum 'PGnumeric = 'PGnumeric

446+ PGSum 'PGinterval = 'PGinterval

447+ PGSum 'PGmoney = 'PGmoney

448+ PGSum pg = TypeError

449+ ( 'Text "Squeal type error: Cannot sum with argument type "

450+ ':<>: 'ShowType pg )

451+

452+-- | A type family that calculates `PGAvg` type of a `PGType`.

453+type family PGAvg ty where

454+ PGAvg 'PGint2 = 'PGnumeric

455+ PGAvg 'PGint4 = 'PGnumeric

456+ PGAvg 'PGint8 = 'PGnumeric

457+ PGAvg 'PGnumeric = 'PGnumeric

458+ PGAvg 'PGfloat4 = 'PGfloat8

459+ PGAvg 'PGfloat8 = 'PGfloat8

460+ PGAvg 'PGinterval = 'PGinterval

461+ PGAvg pg = TypeError

462+ ('Text "Squeal type error: No average for " ':<>: 'ShowType pg)

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Collection.hsnew file+169

@@ -0,0 +1,169 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Collection

3+Description: Array and composite functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Array and composite functions

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DataKinds

14+ , FlexibleContexts

15+ , FlexibleInstances

16+ , MultiParamTypeClasses

17+ , OverloadedLabels

18+ , OverloadedStrings

19+ , RankNTypes

20+ , ScopedTypeVariables

21+ , TypeApplications

22+ , TypeFamilies

23+ , TypeOperators

24+ , UndecidableInstances

25+#-}

26+

27+module Squeal.PostgreSQL.Expression.Collection

28+ ( array

29+ , array1

30+ , array2

31+ , cardinality

32+ , index

33+ , unnest

34+ , row

35+ , field

36+ ) where

37+

38+import Data.String

39+import Data.Word (Word64)

40+

41+import qualified Generics.SOP as SOP

42+

43+import Squeal.PostgreSQL.Alias

44+import Squeal.PostgreSQL.Expression

45+import Squeal.PostgreSQL.Expression.Set

46+import Squeal.PostgreSQL.List

47+import Squeal.PostgreSQL.Render

48+import Squeal.PostgreSQL.Schema

49+

50+-- $setup

51+-- >>> import Squeal.PostgreSQL

52+

53+-- | >>> printSQL $ array [null_, false, true]

54+-- ARRAY[NULL, FALSE, TRUE]

55+array

56+ :: [Expression outer commons grp schemas params from ty]

57+ -- ^ array elements

58+ -> Expression outer commons grp schemas params from (null ('PGvararray ty))

59+array xs = UnsafeExpression $ "ARRAY" <>

60+ bracketed (commaSeparated (renderSQL <$> xs))

61+

62+{- | construct a 1-dimensional fixed length array

63+

64+>>> printSQL $ array1 (null_ :* false *: true)

65+ARRAY[NULL, FALSE, TRUE]

66+

67+>>> :type array1 (null_ :* false *: true)

68+array1 (null_ :* false *: true)

69+ :: Expression

70+ outer

71+ commons

72+ grp

73+ schemas

74+ params

75+ from

76+ (null ('PGfixarray '[3] ('Null 'PGbool)))

77+-}

78+array1

79+ :: (n ~ Length tys, SOP.All ((~) ty) tys)

80+ => NP (Expression outer commons grp schemas params from) tys

81+ -> Expression outer commons grp schemas params from (null ('PGfixarray '[n] ty))

82+array1 xs = UnsafeExpression $ "ARRAY" <>

83+ bracketed (renderCommaSeparated renderSQL xs)

84+

85+{- | construct a 2-dimensional fixed length array

86+

87+>>> printSQL $ array2 ((null_ :* false *: true) *: (false :* null_ *: true))

88+ARRAY[[NULL, FALSE, TRUE], [FALSE, NULL, TRUE]]

89+

90+>>> :type array2 ((null_ :* false *: true) *: (false :* null_ *: true))

91+array2 ((null_ :* false *: true) *: (false :* null_ *: true))

92+ :: Expression

93+ outer

94+ commons

95+ grp

96+ schemas

97+ params

98+ from

99+ (null ('PGfixarray '[2, 3] ('Null 'PGbool)))

100+-}

101+array2

102+ :: ( SOP.All ((~) tys) tyss

103+ , SOP.All SOP.SListI tyss

104+ , Length tyss ~ n1

105+ , SOP.All ((~) ty) tys

106+ , Length tys ~ n2 )

107+ => NP (NP (Expression outer commons grp schemas params from)) tyss

108+ -> Expression outer commons grp schemas params from (null ('PGfixarray '[n1,n2] ty))

109+array2 xss = UnsafeExpression $ "ARRAY" <>

110+ bracketed (renderCommaSeparatedConstraint @SOP.SListI (bracketed . renderCommaSeparated renderSQL) xss)

111+

112+-- | >>> printSQL $ cardinality (array [null_, false, true])

113+-- cardinality(ARRAY[NULL, FALSE, TRUE])

114+cardinality :: null ('PGvararray ty) --> null 'PGint8

115+cardinality = unsafeFunction "cardinality"

116+

117+-- | >>> printSQL $ array [null_, false, true] & index 2

118+-- (ARRAY[NULL, FALSE, TRUE])[2]

119+index

120+ :: Word64 -- ^ index

121+ -> null ('PGvararray ty) --> NullifyType ty

122+index n expr = UnsafeExpression $

123+ parenthesized (renderSQL expr) <> "[" <> fromString (show n) <> "]"

124+

125+-- | Expand an array to a set of rows

126+unnest :: SetFunction "unnest" (null ('PGvararray ty)) '["unnest" ::: ty]

127+unnest = unsafeSetFunction

128+

129+-- | A row constructor is an expression that builds a row value

130+-- (also called a composite value) using values for its member fields.

131+--

132+-- >>> :{

133+-- type Complex = 'PGcomposite

134+-- '[ "real" ::: 'NotNull 'PGfloat8

135+-- , "imaginary" ::: 'NotNull 'PGfloat8 ]

136+-- :}

137+--

138+-- >>> let i = row (0 `as` #real :* 1 `as` #imaginary) :: Expression outer commons grp schemas params from ('NotNull Complex)

139+-- >>> printSQL i

140+-- ROW(0, 1)

141+row

142+ :: SOP.SListI row

143+ => NP (Aliased (Expression outer commons grp schemas params from)) row

144+ -- ^ zero or more expressions for the row field values

145+ -> Expression outer commons grp schemas params from (null ('PGcomposite row))

146+row exprs = UnsafeExpression $ "ROW" <> parenthesized

147+ (renderCommaSeparated (\ (expr `As` _) -> renderSQL expr) exprs)

148+

149+-- | >>> :{

150+-- type Complex = 'PGcomposite

151+-- '[ "real" ::: 'NotNull 'PGfloat8

152+-- , "imaginary" ::: 'NotNull 'PGfloat8 ]

153+-- type Schema = '["complex" ::: 'Typedef Complex]

154+-- :}

155+--

156+-- >>> let i = row (0 `as` #real :* 1 `as` #imaginary) :: Expression outer '[] grp (Public Schema) from params ('NotNull Complex)

157+-- >>> printSQL $ i & field #complex #imaginary

158+-- (ROW(0, 1)::"complex")."imaginary"

159+field

160+ :: ( Has sch schemas schema

161+ , Has tydef schema ('Typedef ('PGcomposite row))

162+ , Has field row ty)

163+ => QualifiedAlias sch tydef -- ^ row type

164+ -> Alias field -- ^ field name

165+ -> Expression outer commons grp schemas params from ('NotNull ('PGcomposite row))

166+ -> Expression outer commons grp schemas params from ty

167+field td fld expr = UnsafeExpression $

168+ parenthesized (renderSQL expr <> "::" <> renderSQL td)

169+ <> "." <> renderSQL fld

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Comparison.hsnew file+206

@@ -0,0 +1,206 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Comparison

3+Description: Comparison expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Comparison functions and operators

9+-}

10+

11+{-# LANGUAGE

12+ OverloadedStrings

13+ , RankNTypes

14+ , TypeInType

15+ , TypeOperators

16+#-}

17+

18+module Squeal.PostgreSQL.Expression.Comparison

19+ ( (.==)

20+ , (./=)

21+ , (.>=)

22+ , (.<)

23+ , (.<=)

24+ , (.>)

25+ , greatest

26+ , least

27+ , BetweenExpr

28+ , between

29+ , notBetween

30+ , betweenSymmetric

31+ , notBetweenSymmetric

32+ , isDistinctFrom

33+ , isNotDistinctFrom

34+ , isTrue

35+ , isNotTrue

36+ , isFalse

37+ , isNotFalse

38+ , isUnknown

39+ , isNotUnknown

40+ ) where

41+

42+import Data.ByteString

43+

44+import Squeal.PostgreSQL.Expression

45+import Squeal.PostgreSQL.Expression.Logic

46+import Squeal.PostgreSQL.Render

47+import Squeal.PostgreSQL.Schema

48+

49+-- $setup

50+-- >>> import Squeal.PostgreSQL

51+

52+-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`

53+-- will produce @NULL@s if one of their arguments is @NULL@.

54+--

55+-- >>> printSQL $ true .== null_

56+-- (TRUE = NULL)

57+(.==) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

58+(.==) = unsafeBinaryOp "="

59+infix 4 .==

60+

61+-- | >>> printSQL $ true ./= null_

62+-- (TRUE <> NULL)

63+(./=) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

64+(./=) = unsafeBinaryOp "<>"

65+infix 4 ./=

66+

67+-- | >>> printSQL $ true .>= null_

68+-- (TRUE >= NULL)

69+(.>=) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

70+(.>=) = unsafeBinaryOp ">="

71+infix 4 .>=

72+

73+-- | >>> printSQL $ true .< null_

74+-- (TRUE < NULL)

75+(.<) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

76+(.<) = unsafeBinaryOp "<"

77+infix 4 .<

78+

79+-- | >>> printSQL $ true .<= null_

80+-- (TRUE <= NULL)

81+(.<=) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

82+(.<=) = unsafeBinaryOp "<="

83+infix 4 .<=

84+

85+-- | >>> printSQL $ true .> null_

86+-- (TRUE > NULL)

87+(.>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

88+(.>) = unsafeBinaryOp ">"

89+infix 4 .>

90+

91+-- | >>> let expr = greatest [param @1] currentTimestamp :: Expression outer commons grp schemas '[ 'NotNull 'PGtimestamptz] from ('NotNull 'PGtimestamptz)

92+-- >>> printSQL expr

93+-- GREATEST(($1 :: timestamp with time zone), CURRENT_TIMESTAMP)

94+greatest :: FunctionVar ty ty ty

95+greatest = unsafeFunctionVar "GREATEST"

96+

97+-- | >>> printSQL $ least [null_] currentTimestamp

98+-- LEAST(NULL, CURRENT_TIMESTAMP)

99+least :: FunctionVar ty ty ty

100+least = unsafeFunctionVar "LEAST"

101+

102+{- |

103+A @RankNType@ for comparison expressions like `between`.

104+-}

105+type BetweenExpr

106+ = forall outer commons grp schemas params from ty

107+ . Expression outer commons grp schemas params from ty

108+ -> ( Expression outer commons grp schemas params from ty

109+ , Expression outer commons grp schemas params from ty ) -- ^ bounds

110+ -> Condition outer commons grp schemas params from

111+

112+unsafeBetweenExpr :: ByteString -> BetweenExpr

113+unsafeBetweenExpr fun a (x,y) = UnsafeExpression $

114+ renderSQL a <+> fun <+> renderSQL x <+> "AND" <+> renderSQL y

115+

116+{- | >>> printSQL $ true `between` (null_, false)

117+TRUE BETWEEN NULL AND FALSE

118+-}

119+between :: BetweenExpr

120+between = unsafeBetweenExpr "BETWEEN"

121+

122+{- | >>> printSQL $ true `notBetween` (null_, false)

123+TRUE NOT BETWEEN NULL AND FALSE

124+-}

125+notBetween :: BetweenExpr

126+notBetween = unsafeBetweenExpr "NOT BETWEEN"

127+

128+{- | between, after sorting the comparison values

129+

130+>>> printSQL $ true `betweenSymmetric` (null_, false)

131+TRUE BETWEEN SYMMETRIC NULL AND FALSE

132+-}

133+betweenSymmetric :: BetweenExpr

134+betweenSymmetric = unsafeBetweenExpr "BETWEEN SYMMETRIC"

135+

136+{- | not between, after sorting the comparison values

137+

138+>>> printSQL $ true `notBetweenSymmetric` (null_, false)

139+TRUE NOT BETWEEN SYMMETRIC NULL AND FALSE

140+-}

141+notBetweenSymmetric :: BetweenExpr

142+notBetweenSymmetric = unsafeBetweenExpr "NOT BETWEEN SYMMETRIC"

143+

144+{- | not equal, treating null like an ordinary value

145+

146+>>> printSQL $ true `isDistinctFrom` null_

147+(TRUE IS DISTINCT FROM NULL)

148+-}

149+isDistinctFrom :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

150+isDistinctFrom = unsafeBinaryOp "IS DISTINCT FROM"

151+

152+{- | equal, treating null like an ordinary value

153+

154+>>> printSQL $ true `isNotDistinctFrom` null_

155+(TRUE IS NOT DISTINCT FROM NULL)

156+-}

157+isNotDistinctFrom :: Operator (null0 ty) (null1 ty) ('NotNull 'PGbool)

158+isNotDistinctFrom = unsafeBinaryOp "IS NOT DISTINCT FROM"

159+

160+{- | is true

161+

162+>>> printSQL $ true & isTrue

163+(TRUE IS TRUE)

164+-}

165+isTrue :: null0 'PGbool --> null1 'PGbool

166+isTrue = unsafeRightOp "IS TRUE"

167+

168+{- | is false or unknown

169+

170+>>> printSQL $ true & isNotTrue

171+(TRUE IS NOT TRUE)

172+-}

173+isNotTrue :: null0 'PGbool --> null1 'PGbool

174+isNotTrue = unsafeRightOp "IS NOT TRUE"

175+

176+{- | is false

177+

178+>>> printSQL $ true & isFalse

179+(TRUE IS FALSE)

180+-}

181+isFalse :: null0 'PGbool --> null1 'PGbool

182+isFalse = unsafeRightOp "IS FALSE"

183+

184+{- | is true or unknown

185+

186+>>> printSQL $ true & isNotFalse

187+(TRUE IS NOT FALSE)

188+-}

189+isNotFalse :: null0 'PGbool --> null1 'PGbool

190+isNotFalse = unsafeRightOp "IS NOT FALSE"

191+

192+{- | is unknown

193+

194+>>> printSQL $ true & isUnknown

195+(TRUE IS UNKNOWN)

196+-}

197+isUnknown :: null0 'PGbool --> null1 'PGbool

198+isUnknown = unsafeRightOp "IS UNKNOWN"

199+

200+{- | is true or false

201+

202+>>> printSQL $ true & isNotUnknown

203+(TRUE IS NOT UNKNOWN)

204+-}

205+isNotUnknown :: null0 'PGbool --> null1 'PGbool

206+isNotUnknown = unsafeRightOp "IS NOT UNKNOWN"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Json.hsnew file+462

@@ -0,0 +1,462 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Json

3+Description: Json and Jsonb functions and operators

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Json and Jsonb functions and operators

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , FlexibleContexts

14+ , FlexibleInstances

15+ , GADTs

16+ , OverloadedLabels

17+ , OverloadedStrings

18+ , PolyKinds

19+ , RankNTypes

20+ , ScopedTypeVariables

21+ , TypeApplications

22+ , TypeOperators

23+ , UndecidableInstances

24+ , UndecidableSuperClasses

25+#-}

26+

27+module Squeal.PostgreSQL.Expression.Json

28+ ( -- * Json and Jsonb operators

29+ (.->)

30+ , (.->>)

31+ , (.#>)

32+ , (.#>>)

33+ -- * Jsonb operators

34+ , (.?)

35+ , (.?|)

36+ , (.?&)

37+ , (.-.)

38+ , (#-.)

39+ -- * Json and Jsonb functions

40+ , toJson

41+ , toJsonb

42+ , arrayToJson

43+ , rowToJson

44+ , jsonBuildArray

45+ , jsonbBuildArray

46+ , JsonBuildObject (..)

47+ , jsonObject

48+ , jsonbObject

49+ , jsonZipObject

50+ , jsonbZipObject

51+ , jsonArrayLength

52+ , jsonbArrayLength

53+ , jsonTypeof

54+ , jsonbTypeof

55+ , jsonStripNulls

56+ , jsonbStripNulls

57+ , jsonbSet

58+ , jsonbInsert

59+ , jsonbPretty

60+ -- * Json and Jsonb set returning functions

61+ , jsonEach

62+ , jsonbEach

63+ , jsonEachText

64+ , jsonbEachText

65+ , jsonObjectKeys

66+ , jsonbObjectKeys

67+ , JsonPopulateFunction

68+ , jsonPopulateRecord

69+ , jsonbPopulateRecord

70+ , jsonPopulateRecordSet

71+ , jsonbPopulateRecordSet

72+ , JsonToRecordFunction

73+ , jsonToRecord

74+ , jsonbToRecord

75+ , jsonToRecordSet

76+ , jsonbToRecordSet

77+ ) where

78+

79+import Data.ByteString (ByteString)

80+import GHC.TypeLits

81+

82+import Squeal.PostgreSQL.Alias

83+import Squeal.PostgreSQL.Expression

84+import Squeal.PostgreSQL.Expression.Set

85+import Squeal.PostgreSQL.Expression.Type

86+import Squeal.PostgreSQL.List

87+import Squeal.PostgreSQL.Query

88+import Squeal.PostgreSQL.Render

89+import Squeal.PostgreSQL.Schema

90+

91+import qualified Generics.SOP as SOP

92+

93+-- $setup

94+-- >>> import Squeal.PostgreSQL

95+-- >>> import Data.Aeson

96+

97+{-----------------------------------------

98+ -- json and jsonb support

99+

100+See https://www.postgresql.org/docs/10/static/functions-json.html -- most

101+comments lifted directly from this page.

102+

103+Table 9.44: json and jsonb operators

104+-----------------------------------------}

105+

106+-- | Get JSON value (object field or array element) at a key.

107+(.->)

108+ :: (json `In` PGJsonType, key `In` PGJsonKey)

109+ => Operator (null json) (null key) ('Null json)

110+infixl 8 .->

111+(.->) = unsafeBinaryOp "->"

112+

113+-- | Get JSON value (object field or array element) at a key, as text.

114+(.->>)

115+ :: (json `In` PGJsonType, key `In` PGJsonKey)

116+ => Operator (null json) (null key) ('Null 'PGtext)

117+infixl 8 .->>

118+(.->>) = unsafeBinaryOp "->>"

119+

120+-- | Get JSON value at a specified path.

121+(.#>)

122+ :: json `In` PGJsonType

123+ => Operator (null json) (null ('PGvararray ('NotNull 'PGtext))) ('Null json)

124+infixl 8 .#>

125+(.#>) = unsafeBinaryOp "#>"

126+

127+-- | Get JSON value at a specified path as text.

128+(.#>>)

129+ :: json `In` PGJsonType

130+ => Operator (null json) (null ('PGvararray ('NotNull 'PGtext))) ('Null 'PGtext)

131+infixl 8 .#>>

132+(.#>>) = unsafeBinaryOp "#>>"

133+

134+-- Additional jsonb operators

135+

136+-- | Does the string exist as a top-level key within the JSON value?

137+(.?) :: Operator (null 'PGjsonb) (null 'PGtext) ('Null 'PGbool)

138+infixl 9 .?

139+(.?) = unsafeBinaryOp "?"

140+

141+-- | Do any of these array strings exist as top-level keys?

142+(.?|) :: Operator

143+ (null 'PGjsonb)

144+ (null ('PGvararray ('NotNull 'PGtext)))

145+ ('Null 'PGbool)

146+infixl 9 .?|

147+(.?|) = unsafeBinaryOp "?|"

148+

149+-- | Do all of these array strings exist as top-level keys?

150+(.?&) :: Operator

151+ (null 'PGjsonb)

152+ (null ('PGvararray ('NotNull 'PGtext)))

153+ ('Null 'PGbool)

154+infixl 9 .?&

155+(.?&) = unsafeBinaryOp "?&"

156+

157+-- | Delete a key or keys from a JSON object, or remove an array element.

158+--

159+-- If the right operand is

160+--

161+-- @ text @: Delete key / value pair or string element from left operand.

162+-- Key / value pairs are matched based on their key value,

163+--

164+-- @ text[] @: Delete multiple key / value pairs or string elements

165+-- from left operand. Key / value pairs are matched based on their key value,

166+--

167+-- @ integer @: Delete the array element with specified index (Negative integers

168+-- count from the end). Throws an error if top level container is not an array.

169+(.-.)

170+ :: key `In` '[ 'PGtext, 'PGvararray ('NotNull 'PGtext), 'PGint4, 'PGint2 ]

171+ => Operator (null 'PGjsonb) (null key) (null 'PGjsonb)

172+infixl 6 .-.

173+(.-.) = unsafeBinaryOp "-"

174+

175+-- | Delete the field or element with specified path (for JSON arrays, negative

176+-- integers count from the end)

177+(#-.) :: Operator (null 'PGjsonb) (null ('PGvararray ('NotNull 'PGtext))) (null 'PGjsonb)

178+infixl 6 #-.

179+(#-.) = unsafeBinaryOp "#-"

180+

181+{-----------------------------------------

182+Table 9.45: JSON creation functions

183+-----------------------------------------}

184+

185+-- | Returns the value as json. Arrays and composites are converted

186+-- (recursively) to arrays and objects; otherwise, if there is a cast from the

187+-- type to json, the cast function will be used to perform the conversion;

188+-- otherwise, a scalar value is produced. For any scalar type other than a

189+-- number, a Boolean, or a null value, the text representation will be used, in

190+-- such a fashion that it is a valid json value.

191+toJson :: null ty --> null 'PGjson

192+toJson = unsafeFunction "to_json"

193+

194+-- | Returns the value as jsonb. Arrays and composites are converted

195+-- (recursively) to arrays and objects; otherwise, if there is a cast from the

196+-- type to json, the cast function will be used to perform the conversion;

197+-- otherwise, a scalar value is produced. For any scalar type other than a

198+-- number, a Boolean, or a null value, the text representation will be used, in

199+-- such a fashion that it is a valid jsonb value.

200+toJsonb :: null ty --> null 'PGjsonb

201+toJsonb = unsafeFunction "to_jsonb"

202+

203+-- | Returns the array as a JSON array. A PostgreSQL multidimensional array

204+-- becomes a JSON array of arrays.

205+arrayToJson :: null ('PGvararray ty) --> null 'PGjson

206+arrayToJson = unsafeFunction "array_to_json"

207+

208+-- | Returns the row as a JSON object.

209+rowToJson :: null ('PGcomposite ty) --> null 'PGjson

210+rowToJson = unsafeFunction "row_to_json"

211+

212+-- | Builds a possibly-heterogeneously-typed JSON array out of a variadic

213+-- argument list.

214+jsonBuildArray :: SOP.SListI tuple => tuple ---> null 'PGjson

215+jsonBuildArray = unsafeFunctionN "json_build_array"

216+

217+-- | Builds a possibly-heterogeneously-typed (binary) JSON array out of a

218+-- variadic argument list.

219+jsonbBuildArray :: SOP.SListI tuple => tuple ---> null 'PGjsonb

220+jsonbBuildArray = unsafeFunctionN "jsonb_build_array"

221+

222+-- | Builds a possibly-heterogeneously-typed JSON object out of a variadic

223+-- argument list. The elements of the argument list must alternate between text

224+-- and values.

225+class SOP.SListI tys => JsonBuildObject tys where

226+

227+ jsonBuildObject :: tys ---> null 'PGjson

228+ jsonBuildObject = unsafeFunctionN "json_build_object"

229+

230+ jsonbBuildObject :: tys ---> null 'PGjsonb

231+ jsonbBuildObject = unsafeFunctionN "jsonb_build_object"

232+

233+instance JsonBuildObject '[]

234+instance (JsonBuildObject tys, key `In` PGJsonKey)

235+ => JsonBuildObject ('NotNull key ': value ': tys)

236+

237+-- | Builds a JSON object out of a text array.

238+-- The array must have two dimensions

239+-- such that each inner array has exactly two elements,

240+-- which are taken as a key/value pair.

241+jsonObject

242+ :: null ('PGfixarray '[n,2] ('NotNull 'PGtext))

243+ --> null 'PGjson

244+jsonObject = unsafeFunction "json_object"

245+

246+-- | Builds a binary JSON object out of a text array.

247+-- The array must have two dimensions

248+-- such that each inner array has exactly two elements,

249+-- which are taken as a key/value pair.

250+jsonbObject

251+ :: null ('PGfixarray '[n,2] ('NotNull 'PGtext))

252+ --> null 'PGjsonb

253+jsonbObject = unsafeFunction "jsonb_object"

254+

255+-- | This is an alternate form of 'jsonObject' that takes two arrays; one for

256+-- keys and one for values, that are zipped pairwise to create a JSON object.

257+jsonZipObject ::

258+ '[ null ('PGvararray ('NotNull 'PGtext))

259+ , null ('PGvararray ('NotNull 'PGtext)) ]

260+ ---> null 'PGjson

261+jsonZipObject = unsafeFunctionN "json_object"

262+

263+-- | This is an alternate form of 'jsonbObject' that takes two arrays; one for

264+-- keys and one for values, that are zipped pairwise to create a binary JSON

265+-- object.

266+jsonbZipObject ::

267+ '[ null ('PGvararray ('NotNull 'PGtext))

268+ , null ('PGvararray ('NotNull 'PGtext)) ]

269+ ---> null 'PGjsonb

270+jsonbZipObject = unsafeFunctionN "jsonb_object"

271+

272+{-----------------------------------------

273+Table 9.46: JSON processing functions

274+-----------------------------------------}

275+

276+-- | Returns the number of elements in the outermost JSON array.

277+jsonArrayLength :: null 'PGjson --> null 'PGint4

278+jsonArrayLength = unsafeFunction "json_array_length"

279+

280+-- | Returns the number of elements in the outermost binary JSON array.

281+jsonbArrayLength :: null 'PGjsonb --> null 'PGint4

282+jsonbArrayLength = unsafeFunction "jsonb_array_length"

283+

284+-- | Returns the type of the outermost JSON value as a text string. Possible

285+-- types are object, array, string, number, boolean, and null.

286+jsonTypeof :: null 'PGjson --> null 'PGtext

287+jsonTypeof = unsafeFunction "json_typeof"

288+

289+-- | Returns the type of the outermost binary JSON value as a text string.

290+-- Possible types are object, array, string, number, boolean, and null.

291+jsonbTypeof :: null 'PGjsonb --> null 'PGtext

292+jsonbTypeof = unsafeFunction "jsonb_typeof"

293+

294+-- | Returns its argument with all object fields that have null values omitted.

295+-- Other null values are untouched.

296+jsonStripNulls :: null 'PGjson --> null 'PGjson

297+jsonStripNulls = unsafeFunction "json_strip_nulls"

298+

299+-- | Returns its argument with all object fields that have null values omitted.

300+-- Other null values are untouched.

301+jsonbStripNulls :: null 'PGjsonb --> null 'PGjsonb

302+jsonbStripNulls = unsafeFunction "jsonb_strip_nulls"

303+

304+-- | @ jsonbSet target path new_value create_missing @

305+--

306+-- Returns target with the section designated by path replaced by @new_value@,

307+-- or with @new_value@ added if create_missing is

308+-- `Squeal.PostgreSQL.Expression.Logic.true` and the

309+-- item designated by path does not exist. As with the path orientated

310+-- operators, negative integers that appear in path count from the end of JSON

311+-- arrays.

312+jsonbSet ::

313+ '[ null 'PGjsonb, null ('PGvararray ('NotNull 'PGtext))

314+ , null 'PGjsonb, null 'PGbool ] ---> null 'PGjsonb

315+jsonbSet = unsafeFunctionN "jsonbSet"

316+

317+-- | @ jsonbInsert target path new_value insert_after @

318+--

319+-- Returns target with @new_value@ inserted. If target section designated by

320+-- path is in a JSONB array, @new_value@ will be inserted before target or after

321+-- if @insert_after@ is `Squeal.PostgreSQL.Expression.Logic.true`.

322+-- If target section designated by

323+-- path is in JSONB object, @new_value@ will be inserted only if target does not

324+-- exist. As with the path orientated operators, negative integers that appear

325+-- in path count from the end of JSON arrays.

326+jsonbInsert ::

327+ '[ null 'PGjsonb, null ('PGvararray ('NotNull 'PGtext))

328+ , null 'PGjsonb, null 'PGbool ] ---> null 'PGjsonb

329+jsonbInsert = unsafeFunctionN "jsonb_insert"

330+

331+-- | Returns its argument as indented JSON text.

332+jsonbPretty :: null 'PGjsonb --> null 'PGtext

333+jsonbPretty = unsafeFunction "jsonb_pretty"

334+

335+{- | Expands the outermost JSON object into a set of key/value pairs.

336+

337+>>> printSQL (select Star (from (jsonEach (literal (Json (object ["a" .= "foo", "b" .= "bar"]))))))

338+SELECT * FROM json_each(('{"a":"foo","b":"bar"}' :: json))

339+-}

340+jsonEach :: SetFunction "json_each" (null 'PGjson)

341+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGjson]

342+jsonEach = unsafeSetFunction

343+

344+{- | Expands the outermost binary JSON object into a set of key/value pairs.

345+

346+>>> printSQL (select Star (from (jsonbEach (literal (Jsonb (object ["a" .= "foo", "b" .= "bar"]))))))

347+SELECT * FROM jsonb_each(('{"a":"foo","b":"bar"}' :: jsonb))

348+-}

349+jsonbEach

350+ :: SetFunction "jsonb_each" (nullity 'PGjsonb)

351+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGjson]

352+jsonbEach = unsafeSetFunction

353+

354+{- | Expands the outermost JSON object into a set of key/value pairs.

355+

356+>>> printSQL (select Star (from (jsonEachText (literal (Json (object ["a" .= "foo", "b" .= "bar"]))))))

357+SELECT * FROM json_each_text(('{"a":"foo","b":"bar"}' :: json))

358+-}

359+jsonEachText

360+ :: SetFunction "json_each_text" (null 'PGjson)

361+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGtext]

362+jsonEachText = unsafeSetFunction

363+

364+{- | Expands the outermost binary JSON object into a set of key/value pairs.

365+

366+>>> printSQL (select Star (from (jsonbEachText (literal (Jsonb (object ["a" .= "foo", "b" .= "bar"]))))))

367+SELECT * FROM jsonb_each_text(('{"a":"foo","b":"bar"}' :: jsonb))

368+-}

369+jsonbEachText

370+ :: SetFunction "jsonb_each_text" (null 'PGjsonb)

371+ '["key" ::: 'NotNull 'PGtext, "value" ::: 'NotNull 'PGtext]

372+jsonbEachText = unsafeSetFunction

373+

374+{- | Returns set of keys in the outermost JSON object.

375+

376+>>> printSQL (jsonObjectKeys (literal (Json (object ["a" .= "foo", "b" .= "bar"]))))

377+json_object_keys(('{"a":"foo","b":"bar"}' :: json))

378+-}

379+jsonObjectKeys

380+ :: SetFunction "json_object_keys" (nullity 'PGjson)

381+ '["json_object_keys" ::: 'NotNull 'PGtext]

382+jsonObjectKeys = unsafeSetFunction

383+

384+{- | Returns set of keys in the outermost JSON object.

385+

386+>>> printSQL (jsonbObjectKeys (literal (Jsonb (object ["a" .= "foo", "b" .= "bar"]))))

387+jsonb_object_keys(('{"a":"foo","b":"bar"}' :: jsonb))

388+-}

389+jsonbObjectKeys

390+ :: SetFunction "jsonb_object_keys" (null 'PGjsonb)

391+ '["jsonb_object_keys" ::: 'NotNull 'PGtext]

392+jsonbObjectKeys = unsafeSetFunction

393+

394+-- | Build rows from Json types.

395+type JsonPopulateFunction fun json

396+ = forall schemas row outer commons params

397+ . json `In` PGJsonType

398+ => TypeExpression schemas ('NotNull ('PGcomposite row)) -- ^ row type

399+ -> Expression outer commons 'Ungrouped schemas params '[] ('NotNull json)

400+ -- ^ json type

401+ -> FromClause outer commons schemas params '[fun ::: row]

402+

403+unsafePopulateFunction

404+ :: forall fun ty

405+ . KnownSymbol fun => Alias fun -> JsonPopulateFunction fun ty

406+unsafePopulateFunction _fun ty expr = UnsafeFromClause $ renderSymbol @fun

407+ <> parenthesized ("null::" <> renderSQL ty <> ", " <> renderSQL expr)

408+

409+-- | Expands the JSON expression to a row whose columns match the record

410+-- type defined by the given table.

411+jsonPopulateRecord :: JsonPopulateFunction "json_populate_record" 'PGjson

412+jsonPopulateRecord = unsafePopulateFunction #json_populate_record

413+

414+-- | Expands the binary JSON expression to a row whose columns match the record

415+-- type defined by the given table.

416+jsonbPopulateRecord :: JsonPopulateFunction "jsonb_populate_record" 'PGjsonb

417+jsonbPopulateRecord = unsafePopulateFunction #jsonb_populate_record

418+

419+-- | Expands the outermost array of objects in the given JSON expression to a

420+-- set of rows whose columns match the record type defined by the given table.

421+jsonPopulateRecordSet :: JsonPopulateFunction "json_populate_record_set" 'PGjson

422+jsonPopulateRecordSet = unsafePopulateFunction #json_populate_record_set

423+

424+-- | Expands the outermost array of objects in the given binary JSON expression

425+-- to a set of rows whose columns match the record type defined by the given

426+-- table.

427+jsonbPopulateRecordSet :: JsonPopulateFunction "jsonb_populate_record_set" 'PGjsonb

428+jsonbPopulateRecordSet = unsafePopulateFunction #jsonb_populate_record_set

429+

430+-- | Build rows from Json types.

431+type JsonToRecordFunction json

432+ = forall outer commons schemas params tab row

433+ . (SOP.SListI row, json `In` PGJsonType)

434+ => Expression outer commons 'Ungrouped schemas params '[] ('NotNull json)

435+ -- ^ json type

436+ -> Aliased (NP (Aliased (TypeExpression schemas))) (tab ::: row)

437+ -- ^ row type

438+ -> FromClause outer commons schemas params '[tab ::: row]

439+

440+unsafeRecordFunction :: ByteString -> JsonToRecordFunction json

441+unsafeRecordFunction fun expr (types `As` tab) = UnsafeFromClause $

442+ fun <> parenthesized (renderSQL expr) <+> "AS" <+> renderSQL tab

443+ <> parenthesized (renderCommaSeparated renderTy types)

444+ where

445+ renderTy :: Aliased (TypeExpression schemas) ty -> ByteString

446+ renderTy (ty `As` alias) = renderSQL alias <+> renderSQL ty

447+

448+-- | Builds an arbitrary record from a JSON object.

449+jsonToRecord :: JsonToRecordFunction 'PGjson

450+jsonToRecord = unsafeRecordFunction "json_to_record"

451+

452+-- | Builds an arbitrary record from a binary JSON object.

453+jsonbToRecord :: JsonToRecordFunction 'PGjsonb

454+jsonbToRecord = unsafeRecordFunction "jsonb_to_record"

455+

456+-- | Builds an arbitrary set of records from a JSON array of objects.

457+jsonToRecordSet :: JsonToRecordFunction 'PGjson

458+jsonToRecordSet = unsafeRecordFunction "json_to_record_set"

459+

460+-- | Builds an arbitrary set of records from a binary JSON array of objects.

461+jsonbToRecordSet :: JsonToRecordFunction 'PGjsonb

462+jsonbToRecordSet = unsafeRecordFunction "jsonb_to_record_set"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Literal.hsnew file+87

@@ -0,0 +1,87 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Literal

3+Description: Literal expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Literal expressions

9+-}

10+

11+{-# LANGUAGE

12+ FlexibleContexts

13+ , FlexibleInstances

14+ , LambdaCase

15+ , OverloadedStrings

16+ , RankNTypes

17+ , ScopedTypeVariables

18+ , TypeApplications

19+ , TypeSynonymInstances

20+ , UndecidableInstances

21+#-}

22+

23+module Squeal.PostgreSQL.Expression.Literal (Literal (..)) where

24+

25+import ByteString.StrictBuilder (builderBytes)

26+import Data.ByteString.Lazy (toStrict)

27+import Data.Int

28+import Data.String

29+import Data.Text (Text)

30+

31+import qualified Data.Aeson as JSON

32+import qualified Data.Text as Text

33+import qualified Data.Text.Lazy as Lazy (Text)

34+import qualified Data.Text.Lazy as Lazy.Text

35+

36+import Squeal.PostgreSQL.Binary

37+import Squeal.PostgreSQL.Expression

38+import Squeal.PostgreSQL.Expression.Logic

39+import Squeal.PostgreSQL.PG

40+import Squeal.PostgreSQL.Render

41+

42+{- |

43+The `Literal` class allows embedding a Haskell value directly

44+as an `Expression` using `literal`.

45+

46+>>> printSQL (literal 'a')

47+E'a'

48+

49+>>> printSQL (literal (1 :: Double))

50+1.0

51+

52+>>> printSQL (literal (Json [1 :: Double, 2]))

53+('[1.0,2.0]' :: json)

54+

55+>>> printSQL (literal (Enumerated GT))

56+'GT'

57+-}

58+class Literal hask where literal :: hask -> Expr (null (PG hask))

59+instance Literal Bool where

60+ literal = \case

61+ True -> true

62+ False -> false

63+instance JSON.ToJSON hask => Literal (Json hask) where

64+ literal = UnsafeExpression . parenthesized . (<> " :: json")

65+ . singleQuotedUtf8 . toStrict . JSON.encode . getJson

66+instance JSON.ToJSON hask => Literal (Jsonb hask) where

67+ literal = UnsafeExpression . parenthesized . (<> " :: jsonb")

68+ . singleQuotedUtf8 . toStrict . JSON.encode . getJsonb

69+instance Literal Char where

70+ literal chr = UnsafeExpression $

71+ "E\'" <> fromString (escape chr) <> "\'"

72+instance Literal String where literal = fromString

73+instance Literal Int16 where literal = fromIntegral

74+instance Literal Int32 where literal = fromIntegral

75+instance Literal Int64 where literal = fromIntegral

76+instance Literal Float where literal = fromRational . toRational

77+instance Literal Double where literal = fromRational . toRational

78+instance Literal Text where literal = fromString . Text.unpack

79+instance Literal Lazy.Text where literal = fromString . Lazy.Text.unpack

80+instance ToParam (Enumerated enum) (PG (Enumerated enum))

81+ => Literal (Enumerated enum) where

82+ literal

83+ = UnsafeExpression

84+ . singleQuotedUtf8

85+ . builderBytes

86+ . unK

87+ . toParam @(Enumerated enum) @(PG (Enumerated enum))

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Logic.hsnew file+105

@@ -0,0 +1,105 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Logic

3+Description: Logical expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Logical expressions and operators

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , OverloadedStrings

14+ , TypeOperators

15+#-}

16+

17+module Squeal.PostgreSQL.Expression.Logic

18+ ( Condition

19+ , true

20+ , false

21+ , not_

22+ , (.&&)

23+ , (.||)

24+ , caseWhenThenElse

25+ , ifThenElse

26+ ) where

27+

28+import Squeal.PostgreSQL.Expression

29+import Squeal.PostgreSQL.Render

30+import Squeal.PostgreSQL.Schema

31+

32+-- | A `Condition` is an `Expression`, which can evaluate

33+-- to `true`, `false` or `Squeal.PostgreSQL.Null.null_`. This is because SQL uses

34+-- a three valued logic.

35+type Condition outer commons grp schemas params from =

36+ Expression outer commons grp schemas params from ('Null 'PGbool)

37+

38+-- | >>> printSQL true

39+-- TRUE

40+true :: Expr (null 'PGbool)

41+true = UnsafeExpression "TRUE"

42+

43+-- | >>> printSQL false

44+-- FALSE

45+false :: Expr (null 'PGbool)

46+false = UnsafeExpression "FALSE"

47+

48+-- | >>> printSQL $ not_ true

49+-- (NOT TRUE)

50+not_ :: null 'PGbool --> null 'PGbool

51+not_ = unsafeLeftOp "NOT"

52+

53+-- | >>> printSQL $ true .&& false

54+-- (TRUE AND FALSE)

55+(.&&) :: Operator (null 'PGbool) (null 'PGbool) (null 'PGbool)

56+infixr 3 .&&

57+(.&&) = unsafeBinaryOp "AND"

58+

59+-- | >>> printSQL $ true .|| false

60+-- (TRUE OR FALSE)

61+(.||) :: Operator (null 'PGbool) (null 'PGbool) (null 'PGbool)

62+infixr 2 .||

63+(.||) = unsafeBinaryOp "OR"

64+

65+-- | >>> :{

66+-- let

67+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)

68+-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3

69+-- in printSQL expression

70+-- :}

71+-- CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END

72+caseWhenThenElse

73+ :: [ ( Condition outer commons grp schemas params from

74+ , Expression outer commons grp schemas params from ty

75+ ) ]

76+ -- ^ whens and thens

77+ -> Expression outer commons grp schemas params from ty

78+ -- ^ else

79+ -> Expression outer commons grp schemas params from ty

80+caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat

81+ [ "CASE"

82+ , mconcat

83+ [ mconcat

84+ [ " WHEN ", renderSQL when_

85+ , " THEN ", renderSQL then_

86+ ]

87+ | (when_,then_) <- whenThens

88+ ]

89+ , " ELSE ", renderSQL else_

90+ , " END"

91+ ]

92+

93+-- | >>> :{

94+-- let

95+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)

96+-- expression = ifThenElse true 1 0

97+-- in printSQL expression

98+-- :}

99+-- CASE WHEN TRUE THEN 1 ELSE 0 END

100+ifThenElse

101+ :: Condition outer commons grp schemas params from

102+ -> Expression outer commons grp schemas params from ty -- ^ then

103+ -> Expression outer commons grp schemas params from ty -- ^ else

104+ -> Expression outer commons grp schemas params from ty

105+ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Math.hsnew file+100

@@ -0,0 +1,100 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Math

3+Description: Math expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Mathematical functions and operators

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , OverloadedStrings

14+ , TypeOperators

15+#-}

16+

17+module Squeal.PostgreSQL.Expression.Math

18+ ( atan2_

19+ , quot_

20+ , rem_

21+ , trunc

22+ , round_

23+ , ceiling_

24+ ) where

25+

26+import Squeal.PostgreSQL.Expression

27+import Squeal.PostgreSQL.List

28+import Squeal.PostgreSQL.Schema

29+

30+-- $setup

31+-- >>> import Squeal.PostgreSQL

32+

33+-- | >>> :{

34+-- let

35+-- expression :: Expr (null 'PGfloat4)

36+-- expression = atan2_ (pi *: 2)

37+-- in printSQL expression

38+-- :}

39+-- atan2(pi(), 2)

40+atan2_ :: float `In` PGFloating => '[ null float, null float] ---> null float

41+atan2_ = unsafeFunctionN "atan2"

42+

43+

44+-- | integer division, truncates the result

45+--

46+-- >>> :{

47+-- let

48+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)

49+-- expression = 5 `quot_` 2

50+-- in printSQL expression

51+-- :}

52+-- (5 / 2)

53+quot_

54+ :: int `In` PGIntegral

55+ => Operator (null int) (null int) (null int)

56+quot_ = unsafeBinaryOp "/"

57+

58+-- | remainder upon integer division

59+--

60+-- >>> :{

61+-- let

62+-- expression :: Expression outer commons grp schemas params from (null 'PGint2)

63+-- expression = 5 `rem_` 2

64+-- in printSQL expression

65+-- :}

66+-- (5 % 2)

67+rem_

68+ :: int `In` PGIntegral

69+ => Operator (null int) (null int) (null int)

70+rem_ = unsafeBinaryOp "%"

71+

72+-- | >>> :{

73+-- let

74+-- expression :: Expression outer commons grp schemas params from (null 'PGfloat4)

75+-- expression = trunc pi

76+-- in printSQL expression

77+-- :}

78+-- trunc(pi())

79+trunc :: frac `In` PGFloating => null frac --> null frac

80+trunc = unsafeFunction "trunc"

81+

82+-- | >>> :{

83+-- let

84+-- expression :: Expression outer commons grp schemas params from (null 'PGfloat4)

85+-- expression = round_ pi

86+-- in printSQL expression

87+-- :}

88+-- round(pi())

89+round_ :: frac `In` PGFloating => null frac --> null frac

90+round_ = unsafeFunction "round"

91+

92+-- | >>> :{

93+-- let

94+-- expression :: Expression outer commons grp schemas params from (null 'PGfloat4)

95+-- expression = ceiling_ pi

96+-- in printSQL expression

97+-- :}

98+-- ceiling(pi())

99+ceiling_ :: frac `In` PGFloating => null frac --> null frac

100+ceiling_ = unsafeFunction "ceiling"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Null.hsnew file+104

@@ -0,0 +1,104 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Null

3+Description: Null

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Null values and null handling functions

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , OverloadedStrings

14+ , TypeOperators

15+#-}

16+

17+module Squeal.PostgreSQL.Expression.Null

18+ ( null_

19+ , notNull

20+ , coalesce

21+ , fromNull

22+ , isNull

23+ , isNotNull

24+ , matchNull

25+ , nullIf

26+ ) where

27+

28+import Squeal.PostgreSQL.Expression

29+import Squeal.PostgreSQL.Expression.Logic

30+import Squeal.PostgreSQL.Render

31+import Squeal.PostgreSQL.Schema

32+

33+-- $setup

34+-- >>> import Squeal.PostgreSQL

35+

36+-- | analagous to `Nothing`

37+--

38+-- >>> printSQL null_

39+-- NULL

40+null_ :: Expr ('Null ty)

41+null_ = UnsafeExpression "NULL"

42+

43+-- | analagous to `Just`

44+--

45+-- >>> printSQL $ notNull true

46+-- TRUE

47+notNull :: 'NotNull ty --> 'Null ty

48+notNull = UnsafeExpression . renderSQL

49+

50+-- | return the leftmost value which is not NULL

51+--

52+-- >>> printSQL $ coalesce [null_, true] false

53+-- COALESCE(NULL, TRUE, FALSE)

54+coalesce :: FunctionVar ('Null ty) ('NotNull ty) ('NotNull ty)

55+coalesce nullxs notNullx = UnsafeExpression $

56+ "COALESCE" <> parenthesized (commaSeparated

57+ ((renderSQL <$> nullxs) <> [renderSQL notNullx]))

58+

59+-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@

60+--

61+-- >>> printSQL $ fromNull true null_

62+-- COALESCE(NULL, TRUE)

63+fromNull

64+ :: Expression outer commons grp schemas params from ('NotNull ty)

65+ -- ^ what to convert @NULL@ to

66+ -> Expression outer commons grp schemas params from ('Null ty)

67+ -> Expression outer commons grp schemas params from ('NotNull ty)

68+fromNull notNullx nullx = coalesce [nullx] notNullx

69+

70+-- | >>> printSQL $ null_ & isNull

71+-- NULL IS NULL

72+isNull :: 'Null ty --> null 'PGbool

73+isNull x = UnsafeExpression $ renderSQL x <+> "IS NULL"

74+

75+-- | >>> printSQL $ null_ & isNotNull

76+-- NULL IS NOT NULL

77+isNotNull :: 'Null ty --> null 'PGbool

78+isNotNull x = UnsafeExpression $ renderSQL x <+> "IS NOT NULL"

79+

80+-- | analagous to `maybe` using @IS NULL@

81+--

82+-- >>> printSQL $ matchNull true not_ null_

83+-- CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END

84+matchNull

85+ :: Expression outer commons grp schemas params from (nullty)

86+ -- ^ what to convert @NULL@ to

87+ -> ( Expression outer commons grp schemas params from ('NotNull ty)

88+ -> Expression outer commons grp schemas params from (nullty) )

89+ -- ^ function to perform when @NULL@ is absent

90+ -> Expression outer commons grp schemas params from ('Null ty)

91+ -> Expression outer commons grp schemas params from (nullty)

92+matchNull y f x = ifThenElse (isNull x) y

93+ (f (UnsafeExpression (renderSQL x)))

94+

95+{-| right inverse to `fromNull`, if its arguments are equal then

96+`nullIf` gives @NULL@.

97+

98+>>> :set -XTypeApplications -XDataKinds

99+>>> let expr = nullIf (false *: param @1) :: Expression outer commons grp schemas '[ 'NotNull 'PGbool] from ('Null 'PGbool)

100+>>> printSQL expr

101+NULLIF(FALSE, ($1 :: bool))

102+-}

103+nullIf :: '[ 'NotNull ty, 'NotNull ty] ---> 'Null ty

104+nullIf = unsafeFunctionN "NULLIF"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Parameter.hsnew file+80

@@ -0,0 +1,80 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Parameter

3+Description: Parameters

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Parameters, out-of-line data values

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DataKinds

14+ , FlexibleContexts

15+ , FlexibleInstances

16+ , FunctionalDependencies

17+ , KindSignatures

18+ , MultiParamTypeClasses

19+ , OverloadedStrings

20+ , RankNTypes

21+ , ScopedTypeVariables

22+ , TypeApplications

23+ , TypeOperators

24+ , UndecidableInstances

25+#-}

26+

27+module Squeal.PostgreSQL.Expression.Parameter

28+ ( HasParameter (parameter)

29+ , param

30+ ) where

31+

32+import GHC.TypeLits

33+

34+import Squeal.PostgreSQL.Expression

35+import Squeal.PostgreSQL.Expression.Type

36+import Squeal.PostgreSQL.Render

37+import Squeal.PostgreSQL.Schema

38+

39+-- $setup

40+-- >>> import Squeal.PostgreSQL

41+

42+{- | A `HasParameter` constraint is used to indicate a value that is

43+supplied externally to a SQL statement.

44+`Squeal.PostgreSQL.PQ.manipulateParams`,

45+`Squeal.PostgreSQL.PQ.queryParams` and

46+`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values

47+separately from the SQL command string, in which case `param`s are used to

48+refer to the out-of-line data values.

49+-}

50+class KnownNat n => HasParameter

51+ (n :: Nat)

52+ (params :: [NullityType])

53+ (ty :: NullityType)

54+ | n params -> ty where

55+ -- | `parameter` takes a `Nat` using type application and a `TypeExpression`.

56+ --

57+ -- >>> let expr = parameter @1 int4 :: Expression outer '[] grp schemas '[ 'Null 'PGint4] from ('Null 'PGint4)

58+ -- >>> printSQL expr

59+ -- ($1 :: int4)

60+ parameter

61+ :: TypeExpression schemas ty

62+ -> Expression outer commons grp schemas params from ty

63+ parameter ty = UnsafeExpression $ parenthesized $

64+ "$" <> renderNat @n <+> "::"

65+ <+> renderSQL ty

66+instance {-# OVERLAPPING #-} HasParameter 1 (ty1:tys) ty1

67+instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) params ty)

68+ => HasParameter n (ty' : params) ty

69+

70+-- | `param` takes a `Nat` using type application and for basic types,

71+-- infers a `TypeExpression`.

72+--

73+-- >>> let expr = param @1 :: Expression outer commons grp schemas '[ 'Null 'PGint4] from ('Null 'PGint4)

74+-- >>> printSQL expr

75+-- ($1 :: int4)

76+param

77+ :: forall n outer commons schemas params from grp ty

78+ . (PGTyped schemas ty, HasParameter n params ty)

79+ => Expression outer commons grp schemas params from ty -- ^ param

80+param = parameter @n (pgtype @schemas)

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Range.hsnew file+230

@@ -0,0 +1,230 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Range

3+Description: range types and functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Range types and functions

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DataKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DeriveFoldable

17+ , DerivingStrategies

18+ , DeriveTraversable

19+ , FlexibleContexts

20+ , FlexibleInstances

21+ , LambdaCase

22+ , MultiParamTypeClasses

23+ , OverloadedLabels

24+ , OverloadedStrings

25+ , PatternSynonyms

26+ , RankNTypes

27+ , ScopedTypeVariables

28+ , TypeApplications

29+ , TypeFamilies

30+ , TypeOperators

31+ , UndecidableInstances

32+#-}

33+

34+module Squeal.PostgreSQL.Expression.Range

35+ ( range

36+ , Range (..)

37+ , (<=..<=), (<..<), (<=..<), (<..<=)

38+ , moreThan, atLeast, lessThan, atMost

39+ , singleton, whole

40+ , Bound (..)

41+ , (.<@)

42+ , (@>.)

43+ , (<<@)

44+ , (@>>)

45+ , (&<)

46+ , (&>)

47+ , (-|-)

48+ , (@+)

49+ , (@*)

50+ , (@-)

51+ , lowerBound

52+ , upperBound

53+ , isEmpty

54+ , lowerInc

55+ , lowerInf

56+ , upperInc

57+ , upperInf

58+ , rangeMerge

59+ ) where

60+

61+import BinaryParser

62+import ByteString.StrictBuilder

63+import Data.Bits

64+import qualified GHC.Generics as GHC

65+import qualified Generics.SOP as SOP

66+import qualified PostgreSQL.Binary.Decoding as Decoding

67+

68+import Squeal.PostgreSQL.Binary

69+import Squeal.PostgreSQL.Expression

70+import Squeal.PostgreSQL.Expression.Type hiding (bool)

71+import Squeal.PostgreSQL.PG

72+import Squeal.PostgreSQL.Render

73+import Squeal.PostgreSQL.Schema

74+

75+-- $setup

76+-- >>> import Squeal.PostgreSQL

77+

78+-- | Construct a `range`

79+--

80+-- >>> printSQL $ range tstzrange (atLeast now)

81+-- tstzrange(now(), NULL, '[)')

82+-- >>> printSQL $ range numrange (0 <=..< 2*pi)

83+-- numrange(0, (2 * pi()), '[)')

84+-- >>> printSQL $ range int4range Empty

85+-- ('empty' :: int4range)

86+range

87+ :: TypeExpression schemas (null ('PGrange ty))

88+ -> Range (Expression outer commons grp schemas params from ('NotNull ty))

89+ -> Expression outer commons grp schemas params from (null ('PGrange ty))

90+range ty = \case

91+ Empty -> UnsafeExpression $ parenthesized

92+ (emp <+> "::" <+> renderSQL ty)

93+ NonEmpty l u -> UnsafeExpression $ renderSQL ty <> parenthesized

94+ (commaSeparated (args l u))

95+ where

96+ emp = singleQuote <> "empty" <> singleQuote

97+ args l u = [arg l, arg u, singleQuote <> bra l <> ket u <> singleQuote]

98+ singleQuote = "\'"

99+ arg = \case

100+ Infinite -> "NULL"; Closed x -> renderSQL x; Open x -> renderSQL x

101+ bra = \case Infinite -> "("; Closed _ -> "["; Open _ -> "("

102+ ket = \case Infinite -> ")"; Closed _ -> "]"; Open _ -> ")"

103+

104+data Bound x = Infinite | Closed x | Open x

105+ deriving

106+ ( Eq, Ord, Show, Read, GHC.Generic

107+ , Functor, Foldable, Traversable )

108+

109+data Range x = Empty | NonEmpty (Bound x) (Bound x)

110+ deriving

111+ ( Eq, Ord, Show, Read, GHC.Generic

112+ , Functor, Foldable, Traversable )

113+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

114+type instance PG (Range x) = 'PGrange (PG x)

115+instance ToParam x pg => ToParam (Range x) ('PGrange pg) where

116+ toParam rng = K $

117+ word8 (setFlags rng 0) <>

118+ case rng of

119+ Empty -> mempty

120+ NonEmpty lower upper -> putBound lower <> putBound upper

121+ where

122+ putBound = \case

123+ Infinite -> mempty

124+ Closed value -> putValue (unK (toParam @x @pg value))

125+ Open value -> putValue (unK (toParam @x @pg value))

126+ putValue value = int32BE (fromIntegral (builderLength value)) <> value

127+ setFlags = \case

128+ Empty -> (`setBit` 0)

129+ NonEmpty lower upper ->

130+ setLowerFlags lower . setUpperFlags upper

131+ setLowerFlags = \case

132+ Infinite -> (`setBit` 3)

133+ Closed _ -> (`setBit` 1)

134+ Open _ -> id

135+ setUpperFlags = \case

136+ Infinite -> (`setBit` 4)

137+ Closed _ -> (`setBit` 2)

138+ Open _ -> id

139+instance FromValue pg y => FromValue ('PGrange pg) (Range y) where

140+ fromValue = do

141+ flag <- byte

142+ if testBit flag 0 then return Empty else do

143+ lower <-

144+ if testBit flag 3

145+ then return Infinite

146+ else do

147+ len <- sized 4 Decoding.int

148+ l <- sized len (fromValue @pg)

149+ return $ if testBit flag 1 then Closed l else Open l

150+ upper <-

151+ if testBit flag 4

152+ then return Infinite

153+ else do

154+ len <- sized 4 Decoding.int

155+ l <- sized len (fromValue @pg)

156+ return $ if testBit flag 2 then Closed l else Open l

157+ return $ NonEmpty lower upper

158+

159+(<=..<=), (<..<), (<=..<), (<..<=) :: x -> x -> Range x

160+infix 4 <=..<=, <..<, <=..<, <..<=

161+x <=..<= y = NonEmpty (Closed x) (Closed y)

162+x <..< y = NonEmpty (Open x) (Open y)

163+x <=..< y = NonEmpty (Closed x) (Open y)

164+x <..<= y = NonEmpty (Open x) (Closed y)

165+

166+moreThan, atLeast, lessThan, atMost :: x -> Range x

167+moreThan x = NonEmpty (Open x) Infinite

168+atLeast x = NonEmpty (Closed x) Infinite

169+lessThan x = NonEmpty Infinite (Open x)

170+atMost x = NonEmpty Infinite (Closed x)

171+

172+singleton :: x -> Range x

173+singleton x = x <=..<= x

174+

175+whole :: Range x

176+whole = NonEmpty Infinite Infinite

177+

178+(.<@) :: Operator ('NotNull ty) (null ('PGrange ty)) ('Null 'PGbool)

179+(.<@) = unsafeBinaryOp "<@"

180+

181+(@>.) :: Operator (null ('PGrange ty)) ('NotNull ty) ('Null 'PGbool)

182+(@>.) = unsafeBinaryOp "<@"

183+

184+(<<@) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)

185+(<<@) = unsafeBinaryOp "<<"

186+

187+(@>>) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)

188+(@>>) = unsafeBinaryOp ">>"

189+

190+(&<) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)

191+(&<) = unsafeBinaryOp "&<"

192+

193+(&>) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)

194+(&>) = unsafeBinaryOp "&>"

195+

196+(-|-) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) ('Null 'PGbool)

197+(-|-) = unsafeBinaryOp "-|-"

198+

199+(@+) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) (null ('PGrange ty))

200+(@+) = unsafeBinaryOp "+"

201+

202+(@*) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) (null ('PGrange ty))

203+(@*) = unsafeBinaryOp "*"

204+

205+(@-) :: Operator (null ('PGrange ty)) (null ('PGrange ty)) (null ('PGrange ty))

206+(@-) = unsafeBinaryOp "-"

207+

208+lowerBound :: null ('PGrange ty) --> 'Null ty

209+lowerBound = unsafeFunction "lower"

210+

211+upperBound :: null ('PGrange ty) --> 'Null ty

212+upperBound = unsafeFunction "upper"

213+

214+isEmpty :: null ('PGrange ty) --> 'Null 'PGbool

215+isEmpty = unsafeFunction "isempty"

216+

217+lowerInc :: null ('PGrange ty) --> 'Null 'PGbool

218+lowerInc = unsafeFunction "lower_inc"

219+

220+lowerInf :: null ('PGrange ty) --> 'Null 'PGbool

221+lowerInf = unsafeFunction "lower_inf"

222+

223+upperInc :: null ('PGrange ty) --> 'Null 'PGbool

224+upperInc = unsafeFunction "upper_inc"

225+

226+upperInf :: null ('PGrange ty) --> 'Null 'PGbool

227+upperInf = unsafeFunction "upper_inf"

228+

229+rangeMerge :: '[null ('PGrange ty), null ('PGrange ty)] ---> null ('PGrange ty)

230+rangeMerge = unsafeFunctionN "range_merge"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Set.hsnew file+139

@@ -0,0 +1,139 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Set

3+Description: Set returning functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Set returning functions

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DataKinds

14+ , FlexibleContexts

15+ , OverloadedStrings

16+ , PolyKinds

17+ , RankNTypes

18+ , ScopedTypeVariables

19+ , TypeApplications

20+ , TypeOperators

21+#-}

22+

23+module Squeal.PostgreSQL.Expression.Set

24+ ( generateSeries

25+ , generateSeriesStep

26+ , generateSeriesTimestamp

27+ , SetFunction

28+ , unsafeSetFunction

29+ , SetFunctionDB

30+ , setFunction

31+ , SetFunctionN

32+ , unsafeSetFunctionN

33+ , SetFunctionNDB

34+ , setFunctionN

35+ ) where

36+

37+import GHC.TypeLits

38+

39+import qualified Generics.SOP as SOP

40+

41+import Squeal.PostgreSQL.Alias

42+import Squeal.PostgreSQL.Expression

43+import Squeal.PostgreSQL.List

44+import Squeal.PostgreSQL.Render

45+import Squeal.PostgreSQL.Query

46+import Squeal.PostgreSQL.Schema

47+

48+{- |

49+A @RankNType@ for set returning functions with 1 argument.

50+-}

51+type SetFunction fun ty row

52+ = forall outer commons schemas params

53+ . Expression outer commons 'Ungrouped schemas params '[] ty

54+ -- ^ input

55+ -> FromClause outer commons schemas params '[fun ::: row]

56+ -- ^ output

57+

58+type SetFunctionDB fun schemas ty row

59+ = forall outer commons params

60+ . Expression outer commons 'Ungrouped schemas params '[] ty

61+ -- ^ input

62+ -> FromClause outer commons schemas params '[fun ::: row]

63+ -- ^ output

64+

65+-- | Escape hatch for a set returning function with 1 argument.

66+unsafeSetFunction

67+ :: forall fun ty row. KnownSymbol fun

68+ => SetFunction fun ty row -- ^ set returning function

69+unsafeSetFunction x = UnsafeFromClause $

70+ renderSymbol @fun <> parenthesized (renderSQL x)

71+

72+setFunction

73+ :: ( Has sch schemas schema

74+ , Has fun schema ('Function ('[ty] :=> 'ReturnsTable row)) )

75+ => QualifiedAlias sch fun

76+ -> SetFunctionDB fun schemas ty row

77+setFunction _ = unsafeSetFunction

78+

79+{- |

80+A @RankNType@ for set returning functions with multiple argument.

81+-}

82+type SetFunctionN fun tys row

83+ = forall outer commons schemas params

84+ . NP (Expression outer commons 'Ungrouped schemas params '[]) tys

85+ -- ^ inputs

86+ -> FromClause outer commons schemas params '[fun ::: row]

87+ -- ^ output

88+

89+-- | Escape hatch for a set returning function with multiple argument.

90+unsafeSetFunctionN

91+ :: forall fun tys row. (SOP.SListI tys, KnownSymbol fun)

92+ => SetFunctionN fun tys row -- ^ set returning function

93+unsafeSetFunctionN xs = UnsafeFromClause $

94+ renderSymbol @fun <> parenthesized (renderCommaSeparated renderSQL xs)

95+

96+type SetFunctionNDB fun schemas tys row

97+ = forall outer commons params

98+ . NP (Expression outer commons 'Ungrouped schemas params '[]) tys

99+ -- ^ inputs

100+ -> FromClause outer commons schemas params '[fun ::: row]

101+ -- ^ output

102+

103+setFunctionN

104+ :: ( Has sch schemas schema

105+ , Has fun schema ('Function (tys :=> 'ReturnsTable row))

106+ , SOP.SListI tys )

107+ => QualifiedAlias sch fun

108+ -> SetFunctionNDB fun schemas tys row

109+setFunctionN _ = unsafeSetFunctionN

110+

111+{- | @generateSeries (start *: stop)@

112+

113+Generate a series of values, from @start@ to @stop@ with a step size of one

114+-}

115+generateSeries

116+ :: ty `In` '[ 'PGint4, 'PGint8, 'PGnumeric]

117+ => SetFunctionN "generate_series" '[ null ty, null ty]

118+ '["generate_series" ::: null ty] -- ^ set returning function

119+generateSeries = unsafeSetFunctionN

120+

121+{- | @generateSeries (start :* stop *: step)@

122+

123+Generate a series of values, from @start@ to @stop@ with a step size of @step@

124+-}

125+generateSeriesStep

126+ :: ty `In` '[ 'PGint4, 'PGint8, 'PGnumeric]

127+ => SetFunctionN "generate_series" '[null ty, null ty, null ty]

128+ '["generate_series" ::: null ty] -- ^ set returning function

129+generateSeriesStep = unsafeSetFunctionN

130+

131+{- | @generateSeries (start :* stop *: step)@

132+

133+Generate a series of values, from @start@ to @stop@ with a step size of @step@

134+-}

135+generateSeriesTimestamp

136+ :: ty `In` '[ 'PGtimestamp, 'PGtimestamptz]

137+ => SetFunctionN "generate_series" '[null ty, null ty, null 'PGinterval]

138+ '["generate_series" ::: null ty] -- ^ set returning function

139+generateSeriesTimestamp = unsafeSetFunctionN

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Sort.hsnew file+85

@@ -0,0 +1,85 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Sort

3+Description: Sort expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Sort expressions

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , GADTs

14+ , LambdaCase

15+ , OverloadedStrings

16+ , StandaloneDeriving

17+#-}

18+

19+module Squeal.PostgreSQL.Expression.Sort

20+ ( SortExpression (..)

21+ , OrderBy (..)

22+ ) where

23+

24+import Squeal.PostgreSQL.Expression

25+import Squeal.PostgreSQL.Render

26+import Squeal.PostgreSQL.Schema

27+

28+-- | `SortExpression`s are used by `orderBy` to optionally sort the results

29+-- of a `Squeal.PostgreSQL.Query.Query`. `Asc` or `Desc`

30+-- set the sort direction of a `NotNull` result

31+-- column to ascending or descending. Ascending order puts smaller values

32+-- first, where "smaller" is defined in terms of the

33+-- `Squeal.PostgreSQL.Expression.Comparison..<` operator. Similarly,

34+-- descending order is determined with the

35+-- `Squeal.PostgreSQL.Expression.Comparison..>` operator. `AscNullsFirst`,

36+-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

37+-- determine whether nulls appear before or after non-null values in the sort

38+-- ordering of a `Null` result column.

39+data SortExpression outer commons grp schemas params from where

40+ Asc

41+ :: Expression outer commons grp schemas params from ('NotNull ty)

42+ -> SortExpression outer commons grp schemas params from

43+ Desc

44+ :: Expression outer commons grp schemas params from ('NotNull ty)

45+ -> SortExpression outer commons grp schemas params from

46+ AscNullsFirst

47+ :: Expression outer commons grp schemas params from ('Null ty)

48+ -> SortExpression outer commons grp schemas params from

49+ AscNullsLast

50+ :: Expression outer commons grp schemas params from ('Null ty)

51+ -> SortExpression outer commons grp schemas params from

52+ DescNullsFirst

53+ :: Expression outer commons grp schemas params from ('Null ty)

54+ -> SortExpression outer commons grp schemas params from

55+ DescNullsLast

56+ :: Expression outer commons grp schemas params from ('Null ty)

57+ -> SortExpression outer commons grp schemas params from

58+deriving instance Show (SortExpression outer commons grp schemas params from)

59+instance RenderSQL (SortExpression outer commons grp schemas params from) where

60+ renderSQL = \case

61+ Asc expression -> renderSQL expression <+> "ASC"

62+ Desc expression -> renderSQL expression <+> "DESC"

63+ AscNullsFirst expression -> renderSQL expression

64+ <+> "ASC NULLS FIRST"

65+ DescNullsFirst expression -> renderSQL expression

66+ <+> "DESC NULLS FIRST"

67+ AscNullsLast expression -> renderSQL expression <+> "ASC NULLS LAST"

68+ DescNullsLast expression -> renderSQL expression <+> "DESC NULLS LAST"

69+

70+{- |

71+The `orderBy` clause causes the result rows of a `Squeal.PostgreSQL.Query.TableExpression`

72+to be sorted according to the specified `SortExpression`(s).

73+If two rows are equal according to the leftmost expression,

74+they are compared according to the next expression and so on.

75+If they are equal according to all specified expressions,

76+they are returned in an implementation-dependent order.

77+

78+You can also control the order in which rows are processed by window functions

79+using `orderBy` within `Squeal.PostgreSQL.Query.Over`.

80+-}

81+class OrderBy expr where

82+ orderBy

83+ :: [SortExpression outer commons grp schemas params from]

84+ -> expr outer commons grp schemas params from

85+ -> expr outer commons grp schemas params from

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Subquery.hsnew file+120

@@ -0,0 +1,120 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Subquery

3+Description: Subquery expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Subquery expressions

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , OverloadedStrings

14+ , RankNTypes

15+ , TypeOperators

16+#-}

17+

18+module Squeal.PostgreSQL.Expression.Subquery

19+ ( exists

20+ , in_

21+ , notIn

22+ , subAll

23+ , subAny

24+ ) where

25+

26+import Squeal.PostgreSQL.Alias

27+import Squeal.PostgreSQL.Expression

28+import Squeal.PostgreSQL.Expression.Logic

29+import Squeal.PostgreSQL.List

30+import Squeal.PostgreSQL.Query

31+import Squeal.PostgreSQL.Render

32+import Squeal.PostgreSQL.Schema

33+

34+-- $setup

35+-- >>> import Squeal.PostgreSQL

36+

37+{- |

38+The argument of `exists` is an arbitrary subquery. The subquery is evaluated

39+to determine whether it returns any rows. If it returns at least one row,

40+the result of `exists` is `true`; if the subquery returns no rows,

41+the result of `exists` is `false`.

42+

43+The subquery can refer to variables from the surrounding query,

44+which will act as constants during any one evaluation of the subquery.

45+

46+The subquery will generally only be executed long enough to determine whether

47+at least one row is returned, not all the way to completion.

48+-}

49+exists

50+ :: Query (Join outer from) commons schemas params row

51+ -> Condition outer commons grp schemas params from

52+exists query = UnsafeExpression $ "EXISTS" <+> parenthesized (renderSQL query)

53+

54+{- |

55+The right-hand side is a parenthesized subquery, which must return

56+exactly one column. The left-hand expression is evaluated and compared to each

57+row of the subquery result using the given `Operator`,

58+which must yield a Boolean result. The result of `subAll` is `true`

59+if all rows yield true (including the case where the subquery returns no rows).

60+The result is `false` if any `false` result is found.

61+The result is `Squeal.PostgreSQL.Expression.Null.null_` if

62+ no comparison with a subquery row returns `false`,

63+and at least one comparison returns `Squeal.PostgreSQL.Expression.Null.null_`.

64+

65+>>> printSQL $ subAll true (.==) (values_ (true `as` #foo))

66+(TRUE = ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo")))

67+-}

68+subAll

69+ :: Expression outer commons grp schemas params from ty1 -- ^ expression

70+ -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator

71+ -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery

72+ -> Condition outer commons grp schemas params from

73+subAll expr (?) qry = expr ?

74+ (UnsafeExpression $ "ALL" <+> parenthesized (renderSQL qry))

75+

76+{- |

77+The right-hand side is a parenthesized subquery, which must return exactly one column.

78+The left-hand expression is evaluated and compared to each row of the subquery result

79+using the given `Operator`, which must yield a Boolean result. The result of `subAny` is `true`

80+if any `true` result is obtained. The result is `false` if no true result is found

81+(including the case where the subquery returns no rows).

82+

83+>>> printSQL $ subAny "foo" like (values_ ("foobar" `as` #foo))

84+(E'foo' LIKE ANY (SELECT * FROM (VALUES (E'foobar')) AS t ("foo")))

85+-}

86+subAny

87+ :: Expression outer commons grp schemas params from ty1 -- ^ expression

88+ -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator

89+ -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery

90+ -> Condition outer commons grp schemas params from

91+subAny expr (?) qry = expr ?

92+ (UnsafeExpression $ "ANY" <+> parenthesized (renderSQL qry))

93+

94+{- |

95+The result is `true` if the left-hand expression's result is equal

96+to any of the right-hand expressions.

97+

98+>>> printSQL $ true `in_` [true, false, null_]

99+TRUE IN (TRUE, FALSE, NULL)

100+-}

101+in_

102+ :: Expression outer commons grp schemas params from ty -- ^ expression

103+ -> [Expression outer commons grp schemas params from ty]

104+ -> Condition outer commons grp schemas params from

105+expr `in_` exprs = UnsafeExpression $ renderSQL expr <+> "IN"

106+ <+> parenthesized (commaSeparated (renderSQL <$> exprs))

107+

108+{- |

109+The result is `true` if the left-hand expression's result is not equal

110+to any of the right-hand expressions.

111+

112+>>> printSQL $ true `notIn` [false, null_]

113+TRUE NOT IN (FALSE, NULL)

114+-}

115+notIn

116+ :: Expression outer commons grp schemas params from ty -- ^ expression

117+ -> [Expression outer commons grp schemas params from ty]

118+ -> Condition outer commons grp schemas params from

119+expr `notIn` exprs = UnsafeExpression $ renderSQL expr <+> "NOT IN"

120+ <+> parenthesized (commaSeparated (renderSQL <$> exprs))

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Text.hsnew file+64

@@ -0,0 +1,64 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Text

3+Description: Text expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+String functions and operators

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , OverloadedStrings

14+ , TypeOperators

15+#-}

16+

17+module Squeal.PostgreSQL.Expression.Text

18+ ( lower

19+ , upper

20+ , charLength

21+ , like

22+ , ilike

23+ ) where

24+

25+import Squeal.PostgreSQL.Expression

26+import Squeal.PostgreSQL.Schema

27+

28+-- $setup

29+-- >>> import Squeal.PostgreSQL

30+

31+-- | >>> printSQL $ lower "ARRRGGG"

32+-- lower(E'ARRRGGG')

33+lower :: null 'PGtext --> null 'PGtext

34+lower = unsafeFunction "lower"

35+

36+-- | >>> printSQL $ upper "eeee"

37+-- upper(E'eeee')

38+upper :: null 'PGtext --> null 'PGtext

39+upper = unsafeFunction "upper"

40+

41+-- | >>> printSQL $ charLength "four"

42+-- char_length(E'four')

43+charLength :: null 'PGtext --> null 'PGint4

44+charLength = unsafeFunction "char_length"

45+

46+-- | The `like` expression returns true if the @string@ matches

47+-- the supplied @pattern@. If @pattern@ does not contain percent signs

48+-- or underscores, then the pattern only represents the string itself;

49+-- in that case `like` acts like the equals operator. An underscore (_)

50+-- in pattern stands for (matches) any single character; a percent sign (%)

51+-- matches any sequence of zero or more characters.

52+--

53+-- >>> printSQL $ "abc" `like` "a%"

54+-- (E'abc' LIKE E'a%')

55+like :: Operator (null 'PGtext) (null 'PGtext) ('Null 'PGbool)

56+like = unsafeBinaryOp "LIKE"

57+

58+-- | The key word ILIKE can be used instead of LIKE to make the

59+-- match case-insensitive according to the active locale.

60+--

61+-- >>> printSQL $ "abc" `ilike` "a%"

62+-- (E'abc' ILIKE E'a%')

63+ilike :: Operator (null 'PGtext) (null 'PGtext) ('Null 'PGbool)

64+ilike = unsafeBinaryOp "ILIKE"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/TextSearch.hsnew file+157

@@ -0,0 +1,157 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.TextSearch

3+Description: Text search expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Text search functions and operators

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , OverloadedStrings

14+ , TypeOperators

15+#-}

16+

17+module Squeal.PostgreSQL.Expression.TextSearch

18+ ( (@@)

19+ , (.&)

20+ , (.|)

21+ , (.!)

22+ , (<->)

23+ , arrayToTSvector

24+ , tsvectorLength

25+ , numnode

26+ , plainToTSquery

27+ , phraseToTSquery

28+ , websearchToTSquery

29+ , queryTree

30+ , toTSquery

31+ , toTSvector

32+ , setWeight

33+ , strip

34+ , jsonToTSvector

35+ , jsonbToTSvector

36+ , tsDelete

37+ , tsFilter

38+ , tsHeadline

39+ ) where

40+

41+import Squeal.PostgreSQL.Expression

42+import Squeal.PostgreSQL.List

43+import Squeal.PostgreSQL.Schema

44+

45+-- | `Squeal.PostgreSQL.Expression.Type.tsvector` matches tsquery ?

46+(@@) :: Operator (null 'PGtsvector) (null 'PGtsquery) ('Null 'PGbool)

47+(@@) = unsafeBinaryOp "@@"

48+

49+-- | AND `Squeal.PostgreSQL.Expression.Type.tsquery`s together

50+(.&) :: Operator (null 'PGtsquery) (null 'PGtsquery) (null 'PGtsquery)

51+(.&) = unsafeBinaryOp "&&"

52+

53+-- | OR `Squeal.PostgreSQL.Expression.Type.tsquery`s together

54+(.|) :: Operator (null 'PGtsquery) (null 'PGtsquery) (null 'PGtsquery)

55+(.|) = unsafeBinaryOp "||"

56+

57+-- | negate a `Squeal.PostgreSQL.Expression.Type.tsquery`

58+(.!) :: null 'PGtsquery --> null 'PGtsquery

59+(.!) = unsafeLeftOp "!!"

60+

61+-- | `Squeal.PostgreSQL.Expression.Type.tsquery` followed by

62+-- `Squeal.PostgreSQL.Expression.Type.tsquery`

63+(<->) :: Operator (null 'PGtsquery) (null 'PGtsquery) (null 'PGtsquery)

64+(<->) = unsafeBinaryOp "<->"

65+

66+-- | convert array of lexemes to `Squeal.PostgreSQL.Expression.Type.tsvector`

67+arrayToTSvector

68+ :: null ('PGvararray ('NotNull 'PGtext))

69+ --> null 'PGtsvector

70+arrayToTSvector = unsafeFunction "array_to_tsvector"

71+

72+-- | number of lexemes in `Squeal.PostgreSQL.Expression.Type.tsvector`

73+tsvectorLength :: null 'PGtsvector --> null 'PGint4

74+tsvectorLength = unsafeFunction "length"

75+

76+-- | number of lexemes plus operators in `Squeal.PostgreSQL.Expression.Type.tsquery`

77+numnode :: null 'PGtsquery --> null 'PGint4

78+numnode = unsafeFunction "numnode"

79+

80+-- | produce `Squeal.PostgreSQL.Expression.Type.tsquery` ignoring punctuation

81+plainToTSquery :: null 'PGtext --> null 'PGtsquery

82+plainToTSquery = unsafeFunction "plainto_tsquery"

83+

84+-- | produce `Squeal.PostgreSQL.Expression.Type.tsquery` that searches for a phrase,

85+-- ignoring punctuation

86+phraseToTSquery :: null 'PGtext --> null 'PGtsquery

87+phraseToTSquery = unsafeFunction "phraseto_tsquery"

88+

89+-- | produce `Squeal.PostgreSQL.Expression.Type.tsquery` from a web search style query

90+websearchToTSquery :: null 'PGtext --> null 'PGtsquery

91+websearchToTSquery = unsafeFunction "websearch_to_tsquery"

92+

93+-- | get indexable part of a `Squeal.PostgreSQL.Expression.Type.tsquery`

94+queryTree :: null 'PGtsquery --> null 'PGtext

95+queryTree = unsafeFunction "query_tree"

96+

97+-- | normalize words and convert to `Squeal.PostgreSQL.Expression.Type.tsquery`

98+toTSquery :: null 'PGtext --> null 'PGtsquery

99+toTSquery = unsafeFunction "to_tsquery"

100+

101+-- | reduce document text to `Squeal.PostgreSQL.Expression.Type.tsvector`

102+toTSvector

103+ :: ty `In` '[ 'PGtext, 'PGjson, 'PGjsonb]

104+ => null ty --> null 'PGtsvector

105+toTSvector = unsafeFunction "to_tsvector"

106+

107+-- | assign weight to each element of `Squeal.PostgreSQL.Expression.Type.tsvector`

108+setWeight :: '[null 'PGtsvector, null ('PGchar 1)] ---> null 'PGtsvector

109+setWeight = unsafeFunctionN "set_weight"

110+

111+-- | remove positions and weights from `Squeal.PostgreSQL.Expression.Type.tsvector`

112+strip :: null 'PGtsvector --> null 'PGtsvector

113+strip = unsafeFunction "strip"

114+

115+-- | @jsonToTSvector (document *: filter)@

116+-- reduce each value in the document, specified by filter to a `Squeal.PostgreSQL.Expression.Type.tsvector`,

117+-- and then concatenate those in document order to produce a single `Squeal.PostgreSQL.Expression.Type.tsvector`.

118+-- filter is a `Squeal.PostgreSQL.Expression.Type.json` array, that enumerates what kind of elements

119+-- need to be included into the resulting `Squeal.PostgreSQL.Expression.Type.tsvector`.

120+-- Possible values for filter are "string" (to include all string values),

121+-- "numeric" (to include all numeric values in the string format),

122+-- "boolean" (to include all Boolean values in the string format "true"/"false"),

123+-- "key" (to include all keys) or "all" (to include all above).

124+-- These values can be combined together to include, e.g. all string and numeric values.

125+jsonToTSvector :: '[null 'PGjson, null 'PGjson] ---> null 'PGtsvector

126+jsonToTSvector = unsafeFunctionN "json_to_tsvector"

127+

128+-- | @jsonbToTSvector (document *: filter)@

129+-- reduce each value in the document, specified by filter to a `Squeal.PostgreSQL.Expression.Type.tsvector`,

130+-- and then concatenate those in document order to produce a single `Squeal.PostgreSQL.Expression.Type.tsvector`.

131+-- filter is a `Squeal.PostgreSQL.Expression.Type.jsonb` array, that enumerates what kind of elements

132+-- need to be included into the resulting `Squeal.PostgreSQL.Expression.Type.tsvector`.

133+-- Possible values for filter are "string" (to include all string values),

134+-- "numeric" (to include all numeric values in the string format),

135+-- "boolean" (to include all Boolean values in the string format "true"/"false"),

136+-- "key" (to include all keys) or "all" (to include all above).

137+-- These values can be combined together to include, e.g. all string and numeric values.

138+jsonbToTSvector :: '[null 'PGjsonb, null 'PGjsonb] ---> null 'PGtsvector

139+jsonbToTSvector = unsafeFunctionN "jsonb_to_tsvector"

140+

141+-- | remove given lexeme from `Squeal.PostgreSQL.Expression.Type.tsvector`

142+tsDelete ::

143+ '[null 'PGtsvector, null ('PGvararray ('NotNull 'PGtext))]

144+ ---> null 'PGtsvector

145+tsDelete = unsafeFunctionN "ts_delete"

146+

147+-- | select only elements with given weights from `Squeal.PostgreSQL.Expression.Type.tsvector`

148+tsFilter ::

149+ '[null 'PGtsvector, null ('PGvararray ('NotNull ('PGchar 1)))]

150+ ---> null 'PGtsvector

151+tsFilter = unsafeFunctionN "ts_filter"

152+

153+-- | display a `Squeal.PostgreSQL.Expression.Type.tsquery` match

154+tsHeadline

155+ :: document `In` '[ 'PGtext, 'PGjson, 'PGjsonb]

156+ => '[null document, null 'PGtsquery] ---> null 'PGtext

157+tsHeadline = unsafeFunctionN "ts_headline"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Time.hsnew file+192

@@ -0,0 +1,192 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Time

3+Description: Date/Time expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Date/Time functions and operators

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , DeriveGeneric

14+ , FunctionalDependencies

15+ , LambdaCase

16+ , MultiParamTypeClasses

17+ , OverloadedStrings

18+ , PolyKinds

19+ , RankNTypes

20+ , TypeOperators

21+#-}

22+

23+module Squeal.PostgreSQL.Expression.Time

24+ ( TimeOp (..)

25+ , currentDate

26+ , currentTime

27+ , currentTimestamp

28+ , localTime

29+ , localTimestamp

30+ , now

31+ , makeDate

32+ , makeTime

33+ , makeTimestamp

34+ , makeTimestamptz

35+ , interval_

36+ , TimeUnit (..)

37+ ) where

38+

39+import Data.String

40+

41+import qualified GHC.Generics as GHC

42+import qualified Generics.SOP as SOP

43+

44+import Squeal.PostgreSQL.Expression

45+import Squeal.PostgreSQL.Render

46+import Squeal.PostgreSQL.Schema

47+

48+-- $setup

49+-- >>> import Squeal.PostgreSQL

50+

51+-- | >>> printSQL currentDate

52+-- CURRENT_DATE

53+currentDate :: Expr (null 'PGdate)

54+currentDate = UnsafeExpression "CURRENT_DATE"

55+

56+-- | >>> printSQL currentTime

57+-- CURRENT_TIME

58+currentTime :: Expr (null 'PGtimetz)

59+currentTime = UnsafeExpression "CURRENT_TIME"

60+

61+-- | >>> printSQL currentTimestamp

62+-- CURRENT_TIMESTAMP

63+currentTimestamp :: Expr (null 'PGtimestamptz)

64+currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"

65+

66+-- | >>> printSQL localTime

67+-- LOCALTIME

68+localTime :: Expr (null 'PGtime)

69+localTime = UnsafeExpression "LOCALTIME"

70+

71+-- | >>> printSQL localTimestamp

72+-- LOCALTIMESTAMP

73+localTimestamp :: Expr (null 'PGtimestamp)

74+localTimestamp = UnsafeExpression "LOCALTIMESTAMP"

75+

76+-- | Current date and time (equivalent to `currentTimestamp`)

77+--

78+-- >>> printSQL now

79+-- now()

80+now :: Expr (null 'PGtimestamptz)

81+now = UnsafeExpression "now()"

82+

83+{-|

84+Create date from year, month and day fields

85+

86+>>> printSQL (makeDate (1984 :* 7 *: 3))

87+make_date(1984, 7, 3)

88+-}

89+makeDate :: '[ null 'PGint4, null 'PGint4, null 'PGint4 ] ---> null 'PGdate

90+makeDate = unsafeFunctionN "make_date"

91+

92+{-|

93+Create time from hour, minute and seconds fields

94+

95+>>> printSQL (makeTime (8 :* 15 *: 23.5))

96+make_time(8, 15, 23.5)

97+-}

98+makeTime :: '[ null 'PGint4, null 'PGint4, null 'PGfloat8 ] ---> null 'PGtime

99+makeTime = unsafeFunctionN "make_time"

100+

101+{-|

102+Create timestamp from year, month, day, hour, minute and seconds fields

103+

104+>>> printSQL (makeTimestamp (2013 :* 7 :* 15 :* 8 :* 15 *: 23.5))

105+make_timestamp(2013, 7, 15, 8, 15, 23.5)

106+-}

107+makeTimestamp ::

108+ '[ null 'PGint4, null 'PGint4, null 'PGint4

109+ , null 'PGint4, null 'PGint4, null 'PGfloat8 ] ---> null 'PGtimestamp

110+makeTimestamp = unsafeFunctionN "make_timestamp"

111+

112+{-|

113+Create timestamp with time zone from

114+year, month, day, hour, minute and seconds fields;

115+the current time zone is used

116+

117+>>> printSQL (makeTimestamptz (2013 :* 7 :* 15 :* 8 :* 15 *: 23.5))

118+make_timestamptz(2013, 7, 15, 8, 15, 23.5)

119+-}

120+makeTimestamptz ::

121+ '[ null 'PGint4, null 'PGint4, null 'PGint4

122+ , null 'PGint4, null 'PGint4, null 'PGfloat8 ] ---> null 'PGtimestamptz

123+makeTimestamptz = unsafeFunctionN "make_timestamptz"

124+

125+{-|

126+Affine space operations on time types.

127+-}

128+class TimeOp time diff | time -> diff where

129+ {-|

130+ >>> printSQL (makeDate (1984 :* 7 *: 3) !+ 365)

131+ (make_date(1984, 7, 3) + 365)

132+ -}

133+ (!+) :: Operator (null time) (null diff) (null time)

134+ (!+) = unsafeBinaryOp "+"

135+ {-|

136+ >>> printSQL (365 +! makeDate (1984 :* 7 *: 3))

137+ (365 + make_date(1984, 7, 3))

138+ -}

139+ (+!) :: Operator (null diff) (null time) (null time)

140+ (+!) = unsafeBinaryOp "+"

141+ {-|

142+ >>> printSQL (makeDate (1984 :* 7 *: 3) !- 365)

143+ (make_date(1984, 7, 3) - 365)

144+ -}

145+ (!-) :: Operator (null time) (null diff) (null time)

146+ (!-) = unsafeBinaryOp "-"

147+ {-|

148+ >>> printSQL (makeDate (1984 :* 7 *: 3) !-! currentDate)

149+ (make_date(1984, 7, 3) - CURRENT_DATE)

150+ -}

151+ (!-!) :: Operator (null time) (null time) (null diff)

152+ (!-!) = unsafeBinaryOp "-"

153+instance TimeOp 'PGtimestamp 'PGinterval

154+instance TimeOp 'PGtimestamptz 'PGinterval

155+instance TimeOp 'PGtime 'PGinterval

156+instance TimeOp 'PGtimetz 'PGinterval

157+instance TimeOp 'PGinterval 'PGinterval

158+instance TimeOp 'PGdate 'PGint4

159+infixl 6 !+

160+infixl 6 +!

161+infixl 6 !-

162+infixl 6 !-!

163+

164+-- | A `TimeUnit` to use in `interval_` construction.

165+data TimeUnit

166+ = Years | Months | Weeks | Days

167+ | Hours | Minutes | Seconds

168+ | Microseconds | Milliseconds

169+ | Decades | Centuries | Millennia

170+ deriving (Eq, Ord, Show, Read, Enum, GHC.Generic)

171+instance SOP.Generic TimeUnit

172+instance SOP.HasDatatypeInfo TimeUnit

173+instance RenderSQL TimeUnit where

174+ renderSQL = \case

175+ Years -> "years"

176+ Months -> "months"

177+ Weeks -> "weeks"

178+ Days -> "days"

179+ Hours -> "hours"

180+ Minutes -> "minutes"

181+ Seconds -> "seconds"

182+ Microseconds -> "microseconds"

183+ Milliseconds -> "milliseconds"

184+ Decades -> "decades"

185+ Centuries -> "centuries"

186+ Millennia -> "millennia"

187+

188+-- | >>> printSQL $ interval_ 7 Days

189+-- (INTERVAL '7.0 days')

190+interval_ :: Double -> TimeUnit -> Expr (null 'PGinterval)

191+interval_ num unit = UnsafeExpression . parenthesized $ "INTERVAL" <+>

192+ "'" <> fromString (show num) <+> renderSQL unit <> "'"

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Type.hsnew file+446

@@ -0,0 +1,446 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression

3+Description: Type expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Type expressions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DataKinds

14+ , DeriveGeneric

15+ , FlexibleContexts

16+ , FlexibleInstances

17+ , GADTs

18+ , GeneralizedNewtypeDeriving

19+ , KindSignatures

20+ , MultiParamTypeClasses

21+ , OverloadedStrings

22+ , RankNTypes

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeOperators

26+ , UndecidableInstances

27+#-}

28+

29+module Squeal.PostgreSQL.Expression.Type

30+ ( -- * type casting

31+ cast

32+ , astype

33+ , inferredtype

34+ -- * type expressions

35+ , TypeExpression (..)

36+ , typedef

37+ , typetable

38+ , typeview

39+ , bool

40+ , int2

41+ , smallint

42+ , int4

43+ , int

44+ , integer

45+ , int8

46+ , bigint

47+ , numeric

48+ , float4

49+ , real

50+ , float8

51+ , doublePrecision

52+ , money

53+ , text

54+ , char

55+ , character

56+ , varchar

57+ , characterVarying

58+ , bytea

59+ , timestamp

60+ , timestampWithTimeZone

61+ , timestamptz

62+ , date

63+ , time

64+ , timeWithTimeZone

65+ , timetz

66+ , interval

67+ , uuid

68+ , inet

69+ , json

70+ , jsonb

71+ , vararray

72+ , fixarray

73+ , tsvector

74+ , tsquery

75+ , oid

76+ , int4range

77+ , int8range

78+ , numrange

79+ , tsrange

80+ , tstzrange

81+ , daterange

82+ -- * column type definitions

83+ , ColumnTypeExpression (..)

84+ , nullable

85+ , notNullable

86+ , default_

87+ , serial2

88+ , smallserial

89+ , serial4

90+ , serial

91+ , serial8

92+ , bigserial

93+ , hask

94+ -- * type inference

95+ , PGTyped (..)

96+ , PGNullityTyped (..)

97+ , FieldTyped (..)

98+ ) where

99+

100+import Control.DeepSeq

101+import Data.ByteString

102+import Data.String

103+import GHC.TypeLits

104+

105+import qualified Data.ByteString as ByteString

106+import qualified GHC.Generics as GHC

107+import qualified Generics.SOP as SOP

108+

109+import Squeal.PostgreSQL.Alias

110+import Squeal.PostgreSQL.Expression

111+import Squeal.PostgreSQL.PG

112+import Squeal.PostgreSQL.Render

113+import Squeal.PostgreSQL.Schema

114+

115+-- $setup

116+-- >>> import Squeal.PostgreSQL

117+

118+-- When a `cast` is applied to an `Expression` of a known type, it

119+-- represents a run-time type conversion. The cast will succeed only if a

120+-- suitable type conversion operation has been defined.

121+--

122+-- | >>> printSQL $ true & cast int4

123+-- (TRUE :: int4)

124+cast

125+ :: TypeExpression schemas ty1

126+ -- ^ type to cast as

127+ -> Expression outer commons grp schemas params from ty0

128+ -- ^ value to convert

129+ -> Expression outer commons grp schemas params from ty1

130+cast ty x = UnsafeExpression $ parenthesized $

131+ renderSQL x <+> "::" <+> renderSQL ty

132+

133+-- | A safe version of `cast` which just matches a value with its type.

134+--

135+-- >>> printSQL (1 & astype int)

136+-- (1 :: int)

137+astype

138+ :: TypeExpression schemas ty

139+ -- ^ type to specify as

140+ -> Expression outer commons grp schemas params from ty

141+ -- ^ value

142+ -> Expression outer commons grp schemas params from ty

143+astype = cast

144+

145+-- | `inferredtype` will add a type annotation to an `Expression`

146+-- which can be useful for fixing the storage type of a value.

147+--

148+-- >>> printSQL (inferredtype true)

149+-- (TRUE :: bool)

150+inferredtype

151+ :: PGTyped schemas ty

152+ => Expression outer common grp schemas params from ty

153+ -- ^ value

154+ -> Expression outer common grp schemas params from ty

155+inferredtype = astype pgtype

156+

157+{-----------------------------------------

158+type expressions

159+-----------------------------------------}

160+

161+-- | `TypeExpression`s are used in `cast`s and

162+-- `Squeal.PostgreSQL.Definition.createTable` commands.

163+newtype TypeExpression (schemas :: SchemasType) (ty :: NullityType)

164+ = UnsafeTypeExpression { renderTypeExpression :: ByteString }

165+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

166+instance RenderSQL (TypeExpression schemas ty) where

167+ renderSQL = renderTypeExpression

168+

169+-- | The enum or composite type in a `Typedef` can be expressed by its alias.

170+typedef

171+ :: (Has sch schemas schema, Has td schema ('Typedef ty))

172+ => QualifiedAlias sch td

173+ -- ^ type alias

174+ -> TypeExpression schemas (null ty)

175+typedef = UnsafeTypeExpression . renderSQL

176+

177+-- | The composite type corresponding to a `Table` definition can be expressed

178+-- by its alias.

179+typetable

180+ :: (Has sch schemas schema, Has tab schema ('Table table))

181+ => QualifiedAlias sch tab

182+ -- ^ table alias

183+ -> TypeExpression schemas (null ('PGcomposite (TableToRow table)))

184+typetable = UnsafeTypeExpression . renderSQL

185+

186+-- | The composite type corresponding to a `View` definition can be expressed

187+-- by its alias.

188+typeview

189+ :: (Has sch schemas schema, Has vw schema ('View view))

190+ => QualifiedAlias sch vw

191+ -- ^ view alias

192+ -> TypeExpression schemas (null ('PGcomposite view))

193+typeview = UnsafeTypeExpression . renderSQL

194+

195+-- | logical Boolean (true/false)

196+bool :: TypeExpression schemas (null 'PGbool)

197+bool = UnsafeTypeExpression "bool"

198+-- | signed two-byte integer

199+int2, smallint :: TypeExpression schemas (null 'PGint2)

200+int2 = UnsafeTypeExpression "int2"

201+smallint = UnsafeTypeExpression "smallint"

202+-- | signed four-byte integer

203+int4, int, integer :: TypeExpression schemas (null 'PGint4)

204+int4 = UnsafeTypeExpression "int4"

205+int = UnsafeTypeExpression "int"

206+integer = UnsafeTypeExpression "integer"

207+-- | signed eight-byte integer

208+int8, bigint :: TypeExpression schemas (null 'PGint8)

209+int8 = UnsafeTypeExpression "int8"

210+bigint = UnsafeTypeExpression "bigint"

211+-- | arbitrary precision numeric type

212+numeric :: TypeExpression schemas (null 'PGnumeric)

213+numeric = UnsafeTypeExpression "numeric"

214+-- | single precision floating-point number (4 bytes)

215+float4, real :: TypeExpression schemas (null 'PGfloat4)

216+float4 = UnsafeTypeExpression "float4"

217+real = UnsafeTypeExpression "real"

218+-- | double precision floating-point number (8 bytes)

219+float8, doublePrecision :: TypeExpression schemas (null 'PGfloat8)

220+float8 = UnsafeTypeExpression "float8"

221+doublePrecision = UnsafeTypeExpression "double precision"

222+-- | currency amount

223+money :: TypeExpression schema (null 'PGmoney)

224+money = UnsafeTypeExpression "money"

225+-- | variable-length character string

226+text :: TypeExpression schemas (null 'PGtext)

227+text = UnsafeTypeExpression "text"

228+-- | fixed-length character string

229+char, character

230+ :: forall n schemas null. (KnownNat n, 1 <= n)

231+ => TypeExpression schemas (null ('PGchar n))

232+char = UnsafeTypeExpression $ "char(" <> renderNat @n <> ")"

233+character = UnsafeTypeExpression $ "character(" <> renderNat @n <> ")"

234+-- | variable-length character string

235+varchar, characterVarying

236+ :: forall n schemas null. (KnownNat n, 1 <= n)

237+ => TypeExpression schemas (null ('PGvarchar n))

238+varchar = UnsafeTypeExpression $ "varchar(" <> renderNat @n <> ")"

239+characterVarying = UnsafeTypeExpression $

240+ "character varying(" <> renderNat @n <> ")"

241+-- | binary data ("byte array")

242+bytea :: TypeExpression schemas (null 'PGbytea)

243+bytea = UnsafeTypeExpression "bytea"

244+-- | date and time (no time zone)

245+timestamp :: TypeExpression schemas (null 'PGtimestamp)

246+timestamp = UnsafeTypeExpression "timestamp"

247+-- | date and time, including time zone

248+timestampWithTimeZone, timestamptz :: TypeExpression schemas (null 'PGtimestamptz)

249+timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"

250+timestamptz = UnsafeTypeExpression "timestamptz"

251+-- | calendar date (year, month, day)

252+date :: TypeExpression schemas (null 'PGdate)

253+date = UnsafeTypeExpression "date"

254+-- | time of day (no time zone)

255+time :: TypeExpression schemas (null 'PGtime)

256+time = UnsafeTypeExpression "time"

257+-- | time of day, including time zone

258+timeWithTimeZone, timetz :: TypeExpression schemas (null 'PGtimetz)

259+timeWithTimeZone = UnsafeTypeExpression "time with time zone"

260+timetz = UnsafeTypeExpression "timetz"

261+-- | time span

262+interval :: TypeExpression schemas (null 'PGinterval)

263+interval = UnsafeTypeExpression "interval"

264+-- | universally unique identifier

265+uuid :: TypeExpression schemas (null 'PGuuid)

266+uuid = UnsafeTypeExpression "uuid"

267+-- | IPv4 or IPv6 host address

268+inet :: TypeExpression schemas (null 'PGinet)

269+inet = UnsafeTypeExpression "inet"

270+-- | textual JSON data

271+json :: TypeExpression schemas (null 'PGjson)

272+json = UnsafeTypeExpression "json"

273+-- | binary JSON data, decomposed

274+jsonb :: TypeExpression schemas (null 'PGjsonb)

275+jsonb = UnsafeTypeExpression "jsonb"

276+-- | variable length array

277+vararray

278+ :: TypeExpression schemas pg

279+ -> TypeExpression schemas (null ('PGvararray pg))

280+vararray ty = UnsafeTypeExpression $ renderSQL ty <> "[]"

281+-- | fixed length array

282+--

283+-- >>> renderSQL (fixarray @'[2] json)

284+-- "json[2]"

285+fixarray

286+ :: forall dims schemas null pg. SOP.All KnownNat dims

287+ => TypeExpression schemas pg

288+ -> TypeExpression schemas (null ('PGfixarray dims pg))

289+fixarray ty = UnsafeTypeExpression $

290+ renderSQL ty <> renderDims @dims

291+ where

292+ renderDims :: forall ns. SOP.All KnownNat ns => ByteString

293+ renderDims =

294+ ("[" <>)

295+ . (<> "]")

296+ . ByteString.intercalate "]["

297+ . SOP.hcollapse

298+ $ SOP.hcmap (SOP.Proxy @KnownNat)

299+ (K . fromString . show . natVal)

300+ (SOP.hpure SOP.Proxy :: SOP.NP SOP.Proxy ns)

301+-- | text search query

302+tsvector :: TypeExpression schemas (null 'PGtsvector)

303+tsvector = UnsafeTypeExpression "tsvector"

304+-- | text search document

305+tsquery :: TypeExpression schemas (null 'PGtsquery)

306+tsquery = UnsafeTypeExpression "tsquery"

307+-- | Object identifiers (OIDs) are used internally by PostgreSQL

308+-- as primary keys for various system tables.

309+oid :: TypeExpression schemas (null 'PGoid)

310+oid = UnsafeTypeExpression "oid"

311+-- | Range of integer

312+int4range :: TypeExpression schemas (null ('PGrange 'PGint4))

313+int4range = UnsafeTypeExpression "int4range"

314+-- | Range of bigint

315+int8range :: TypeExpression schemas (null ('PGrange 'PGint8))

316+int8range = UnsafeTypeExpression "int8range"

317+-- | Range of numeric

318+numrange :: TypeExpression schemas (null ('PGrange 'PGnumeric))

319+numrange = UnsafeTypeExpression "numrange"

320+-- | Range of timestamp without time zone

321+tsrange :: TypeExpression schemas (null ('PGrange 'PGtimestamp))

322+tsrange = UnsafeTypeExpression "tsrange"

323+-- | Range of timestamp with time zone

324+tstzrange :: TypeExpression schemas (null ('PGrange 'PGtimestamptz))

325+tstzrange = UnsafeTypeExpression "tstzrange"

326+-- | Range of date

327+daterange :: TypeExpression schemas (null ('PGrange 'PGdate))

328+daterange = UnsafeTypeExpression "daterange"

329+

330+-- | `pgtype` is a demoted version of a `PGType`

331+class PGTyped schemas (ty :: NullityType) where

332+ pgtype :: TypeExpression schemas ty

333+instance PGTyped schemas (null 'PGbool) where pgtype = bool

334+instance PGTyped schemas (null 'PGint2) where pgtype = int2

335+instance PGTyped schemas (null 'PGint4) where pgtype = int4

336+instance PGTyped schemas (null 'PGint8) where pgtype = int8

337+instance PGTyped schemas (null 'PGnumeric) where pgtype = numeric

338+instance PGTyped schemas (null 'PGfloat4) where pgtype = float4

339+instance PGTyped schemas (null 'PGfloat8) where pgtype = float8

340+instance PGTyped schemas (null 'PGmoney) where pgtype = money

341+instance PGTyped schemas (null 'PGtext) where pgtype = text

342+instance (KnownNat n, 1 <= n)

343+ => PGTyped schemas (null ('PGchar n)) where pgtype = char @n

344+instance (KnownNat n, 1 <= n)

345+ => PGTyped schemas (null ('PGvarchar n)) where pgtype = varchar @n

346+instance PGTyped schemas (null 'PGbytea) where pgtype = bytea

347+instance PGTyped schemas (null 'PGtimestamp) where pgtype = timestamp

348+instance PGTyped schemas (null 'PGtimestamptz) where pgtype = timestampWithTimeZone

349+instance PGTyped schemas (null 'PGdate) where pgtype = date

350+instance PGTyped schemas (null 'PGtime) where pgtype = time

351+instance PGTyped schemas (null 'PGtimetz) where pgtype = timeWithTimeZone

352+instance PGTyped schemas (null 'PGinterval) where pgtype = interval

353+instance PGTyped schemas (null 'PGuuid) where pgtype = uuid

354+instance PGTyped schemas (null 'PGjson) where pgtype = json

355+instance PGTyped schemas (null 'PGjsonb) where pgtype = jsonb

356+instance PGTyped schemas ty

357+ => PGTyped schemas (null ('PGvararray ty)) where

358+ pgtype = vararray (pgtype @schemas @ty)

359+instance (SOP.All KnownNat dims, PGTyped schemas ty)

360+ => PGTyped schemas (null ('PGfixarray dims ty)) where

361+ pgtype = fixarray @dims (pgtype @schemas @ty)

362+instance PGTyped schemas (null 'PGtsvector) where pgtype = tsvector

363+instance PGTyped schemas (null 'PGtsquery) where pgtype = tsquery

364+instance PGTyped schemas (null 'PGoid) where pgtype = oid

365+instance PGTyped schemas (null ('PGrange 'PGint4)) where pgtype = int4range

366+instance PGTyped schemas (null ('PGrange 'PGint8)) where pgtype = int8range

367+instance PGTyped schemas (null ('PGrange 'PGnumeric)) where pgtype = numrange

368+instance PGTyped schemas (null ('PGrange 'PGtimestamp)) where pgtype = tsrange

369+instance PGTyped schemas (null ('PGrange 'PGtimestamptz)) where pgtype = tstzrange

370+instance PGTyped schemas (null ('PGrange 'PGdate)) where pgtype = daterange

371+

372+-- | Lift `PGTyped` to a field

373+class FieldTyped schemas ty where

374+ fieldtype :: Aliased (TypeExpression schemas) ty

375+instance (KnownSymbol alias, PGTyped schemas ty)

376+ => FieldTyped schemas (alias ::: ty) where

377+ fieldtype = pgtype `As` Alias

378+

379+-- | `ColumnTypeExpression`s are used in `createTable` commands.

380+newtype ColumnTypeExpression (schemas :: SchemasType) (ty :: ColumnType)

381+ = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }

382+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

383+instance RenderSQL (ColumnTypeExpression schemas ty) where

384+ renderSQL = renderColumnTypeExpression

385+

386+-- | used in `createTable` commands as a column constraint to note that

387+-- @NULL@ may be present in a column

388+nullable

389+ :: TypeExpression schemas (nullity ty)

390+ -> ColumnTypeExpression schemas ('NoDef :=> 'Null ty)

391+nullable ty = UnsafeColumnTypeExpression $ renderSQL ty <+> "NULL"

392+

393+-- | used in `createTable` commands as a column constraint to ensure

394+-- @NULL@ is not present in a column

395+notNullable

396+ :: TypeExpression schemas (nullity ty)

397+ -> ColumnTypeExpression schemas ('NoDef :=> 'NotNull ty)

398+notNullable ty = UnsafeColumnTypeExpression $ renderSQL ty <+> "NOT NULL"

399+

400+-- | used in `createTable` commands as a column constraint to give a default

401+default_

402+ :: Expression '[] '[] 'Ungrouped schemas '[] '[] ty

403+ -> ColumnTypeExpression schemas ('NoDef :=> ty)

404+ -> ColumnTypeExpression schemas ('Def :=> ty)

405+default_ x ty = UnsafeColumnTypeExpression $

406+ renderSQL ty <+> "DEFAULT" <+> renderExpression x

407+

408+-- | not a true type, but merely a notational convenience for creating

409+-- unique identifier columns with type `PGint2`

410+serial2, smallserial

411+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint2)

412+serial2 = UnsafeColumnTypeExpression "serial2"

413+smallserial = UnsafeColumnTypeExpression "smallserial"

414+-- | not a true type, but merely a notational convenience for creating

415+-- unique identifier columns with type `PGint4`

416+serial4, serial

417+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint4)

418+serial4 = UnsafeColumnTypeExpression "serial4"

419+serial = UnsafeColumnTypeExpression "serial"

420+-- | not a true type, but merely a notational convenience for creating

421+-- unique identifier columns with type `PGint8`

422+serial8, bigserial

423+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint8)

424+serial8 = UnsafeColumnTypeExpression "serial8"

425+bigserial = UnsafeColumnTypeExpression "bigserial"

426+

427+-- | Like @PGTyped@ but also accounts for nullity.

428+class PGNullityTyped schemas (nullty :: NullityType) where

429+ pgNullityType :: ColumnTypeExpression schemas ('NoDef :=> nullty)

430+

431+instance PGTyped schemas ('Null ty) => PGNullityTyped schemas ('Null ty) where

432+ pgNullityType = nullable (pgtype @_ @('Null ty))

433+

434+instance PGTyped schemas ('NotNull ty) => PGNullityTyped schemas ('NotNull ty) where

435+ pgNullityType = notNullable (pgtype @_ @('NotNull ty))

436+

437+-- | Allow you to specify pg column types in relation to haskell types.

438+-- >>> printSQL $ hask @(Maybe String)

439+-- text NULL

440+--

441+-- >>> printSQL $ hask @Double

442+-- float8 NOT NULL

443+hask

444+ :: forall hask schemas. PGNullityTyped schemas (NullPG hask)

445+ => ColumnTypeExpression schemas ('NoDef :=> NullPG hask)

446+hask = pgNullityType

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Window.hsnew file+284

@@ -0,0 +1,284 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Window

3+Description: Window functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Window functions and definitions

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , DeriveGeneric

14+ , FlexibleContexts

15+ , FlexibleInstances

16+ , GADTs

17+ , GeneralizedNewtypeDeriving

18+ , LambdaCase

19+ , MultiParamTypeClasses

20+ , OverloadedStrings

21+ , RankNTypes

22+ , KindSignatures

23+#-}

24+

25+module Squeal.PostgreSQL.Expression.Window

26+ ( -- * functions

27+ partitionBy

28+ , rank

29+ , rowNumber

30+ , denseRank

31+ , percentRank

32+ , cumeDist

33+ , ntile

34+ , lag

35+ , lead

36+ , firstValue

37+ , lastValue

38+ , nthValue

39+ , unsafeWindowFunction1

40+ , unsafeWindowFunctionN

41+ -- * types

42+ , WindowFunction (..)

43+ , WindowDefinition (..)

44+ , WinFun0

45+ , WinFun1

46+ , WinFunN

47+ ) where

48+

49+import Control.DeepSeq

50+import Data.ByteString

51+

52+import qualified GHC.Generics as GHC

53+import qualified Generics.SOP as SOP

54+

55+import Squeal.PostgreSQL.Alias

56+import Squeal.PostgreSQL.Expression

57+import Squeal.PostgreSQL.Expression.Aggregate

58+import Squeal.PostgreSQL.Expression.Sort

59+import Squeal.PostgreSQL.List

60+import Squeal.PostgreSQL.Render

61+import Squeal.PostgreSQL.Schema

62+

63+instance Aggregate

64+ (Expression outer commons grp schemas params from)

65+ (NP (Expression outer commons grp schemas params from))

66+ (WindowFunction outer commons grp schemas params from) where

67+ countStar = UnsafeWindowFunction "count(*)"

68+ count = unsafeWindowFunction1 "count"

69+ sum_ = unsafeWindowFunction1 "sum"

70+ arrayAgg = unsafeWindowFunction1 "array_agg"

71+ jsonAgg = unsafeWindowFunction1 "json_agg"

72+ jsonbAgg = unsafeWindowFunction1 "jsonb_agg"

73+ bitAnd = unsafeWindowFunction1 "bit_and"

74+ bitOr = unsafeWindowFunction1 "bit_or"

75+ boolAnd = unsafeWindowFunction1 "bool_and"

76+ boolOr = unsafeWindowFunction1 "bool_or"

77+ every = unsafeWindowFunction1 "every"

78+ max_ = unsafeWindowFunction1 "max"

79+ min_ = unsafeWindowFunction1 "min"

80+ avg = unsafeWindowFunction1 "avg"

81+ corr = unsafeWindowFunctionN "corr"

82+ covarPop = unsafeWindowFunctionN "covar_pop"

83+ covarSamp = unsafeWindowFunctionN "covar_samp"

84+ regrAvgX = unsafeWindowFunctionN "regr_avgx"

85+ regrAvgY = unsafeWindowFunctionN "regr_avgy"

86+ regrCount = unsafeWindowFunctionN "regr_count"

87+ regrIntercept = unsafeWindowFunctionN "regr_intercept"

88+ regrR2 = unsafeWindowFunctionN "regr_r2"

89+ regrSlope = unsafeWindowFunctionN "regr_slope"

90+ regrSxx = unsafeWindowFunctionN "regr_sxx"

91+ regrSxy = unsafeWindowFunctionN "regr_sxy"

92+ regrSyy = unsafeWindowFunctionN "regr_syy"

93+ stddev = unsafeWindowFunction1 "stddev"

94+ stddevPop = unsafeWindowFunction1 "stddev_pop"

95+ stddevSamp = unsafeWindowFunction1 "stddev_samp"

96+ variance = unsafeWindowFunction1 "variance"

97+ varPop = unsafeWindowFunction1 "var_pop"

98+ varSamp = unsafeWindowFunction1 "var_samp"

99+

100+-- | A `WindowDefinition` is a set of table rows that are somehow related

101+-- to the current row

102+data WindowDefinition outer commons grp schemas params from where

103+ WindowDefinition

104+ :: SOP.SListI bys

105+ => NP (Expression outer commons grp schemas params from) bys

106+ -- ^ `partitionBy` clause

107+ -> [SortExpression outer commons grp schemas params from]

108+ -- ^ `Squeal.PostgreSQL.Expression.Sort.orderBy` clause

109+ -> WindowDefinition outer commons grp schemas params from

110+

111+instance OrderBy WindowDefinition where

112+ orderBy sortsR (WindowDefinition parts sortsL)

113+ = WindowDefinition parts (sortsL ++ sortsR)

114+

115+instance RenderSQL (WindowDefinition outer commons schemas from grp params) where

116+ renderSQL (WindowDefinition part ord) =

117+ renderPartitionByClause part <> renderOrderByClause ord

118+ where

119+ renderPartitionByClause = \case

120+ Nil -> ""

121+ parts -> "PARTITION" <+> "BY" <+> renderCommaSeparated renderExpression parts

122+ renderOrderByClause = \case

123+ [] -> ""

124+ srts -> " ORDER" <+> "BY"

125+ <+> commaSeparated (renderSQL <$> srts)

126+

127+{- |

128+The `partitionBy` clause within `Squeal.PostgreSQL.Query.Over` divides the rows into groups,

129+or partitions, that share the same values of the `partitionBy` `Expression`(s).

130+For each row, the window function is computed across the rows that fall into

131+the same partition as the current row.

132+-}

133+partitionBy

134+ :: SOP.SListI bys

135+ => NP (Expression outer commons grp schemas params from) bys -- ^ partitions

136+ -> WindowDefinition outer commons grp schemas params from

137+partitionBy bys = WindowDefinition bys []

138+

139+{- |

140+A window function performs a calculation across a set of table rows

141+that are somehow related to the current row. This is comparable to the type

142+of calculation that can be done with an aggregate function.

143+However, window functions do not cause rows to become grouped into a single

144+output row like non-window aggregate calls would.

145+Instead, the rows retain their separate identities.

146+Behind the scenes, the window function is able to access more than

147+just the current row of the query result.

148+-}

149+newtype WindowFunction

150+ (outer :: FromType)

151+ (commons :: FromType)

152+ (grp :: Grouping)

153+ (schemas :: SchemasType)

154+ (params :: [NullityType])

155+ (from :: FromType)

156+ (ty :: NullityType)

157+ = UnsafeWindowFunction { renderWindowFunction :: ByteString }

158+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

159+

160+instance RenderSQL (WindowFunction outer commons grp schemas params from ty) where

161+ renderSQL = renderWindowFunction

162+

163+{- |

164+A @RankNType@ for window functions with no arguments.

165+-}

166+type WinFun0 x

167+ = forall outer commons grp schemas params from

168+ . WindowFunction outer commons grp schemas params from x

169+ -- ^ cannot reference aliases

170+

171+{- |

172+A @RankNType@ for window functions with 1 argument.

173+-}

174+type WinFun1 x y

175+ = forall outer commons grp schemas params from

176+ . Expression outer commons grp schemas params from x

177+ -- ^ input

178+ -> WindowFunction outer commons grp schemas params from y

179+ -- ^ output

180+

181+{- | A @RankNType@ for window functions with a fixed-length

182+list of heterogeneous arguments.

183+Use the `*:` operator to end your argument lists.

184+-}

185+type WinFunN xs y

186+ = forall outer commons grp schemas params from

187+ . NP (Expression outer commons grp schemas params from) xs

188+ -- ^ inputs

189+ -> WindowFunction outer commons grp schemas params from y

190+ -- ^ output

191+

192+-- | escape hatch for defining window functions

193+unsafeWindowFunction1 :: ByteString -> WinFun1 x y

194+unsafeWindowFunction1 fun x

195+ = UnsafeWindowFunction $ fun <> parenthesized (renderSQL x)

196+

197+-- | escape hatch for defining multi-argument window functions

198+unsafeWindowFunctionN :: SOP.SListI xs => ByteString -> WinFunN xs y

199+unsafeWindowFunctionN fun xs = UnsafeWindowFunction $ fun <>

200+ parenthesized (renderCommaSeparated renderSQL xs)

201+

202+{- | rank of the current row with gaps; same as `rowNumber` of its first peer

203+

204+>>> printSQL rank

205+rank()

206+-}

207+rank :: WinFun0 ('NotNull 'PGint8)

208+rank = UnsafeWindowFunction "rank()"

209+

210+{- | number of the current row within its partition, counting from 1

211+

212+>>> printSQL rowNumber

213+row_number()

214+-}

215+rowNumber :: WinFun0 ('NotNull 'PGint8)

216+rowNumber = UnsafeWindowFunction "row_number()"

217+

218+{- | rank of the current row without gaps; this function counts peer groups

219+

220+>>> printSQL denseRank

221+dense_rank()

222+-}

223+denseRank :: WinFun0 ('NotNull 'PGint8)

224+denseRank = UnsafeWindowFunction "dense_rank()"

225+

226+{- | relative rank of the current row: (rank - 1) / (total partition rows - 1)

227+

228+>>> printSQL percentRank

229+percent_rank()

230+-}

231+percentRank :: WinFun0 ('NotNull 'PGfloat8)

232+percentRank = UnsafeWindowFunction "percent_rank()"

233+

234+{- | cumulative distribution: (number of partition rows

235+preceding or peer with current row) / total partition rows

236+

237+>>> printSQL cumeDist

238+cume_dist()

239+-}

240+cumeDist :: WinFun0 ('NotNull 'PGfloat8)

241+cumeDist = UnsafeWindowFunction "cume_dist()"

242+

243+{- | integer ranging from 1 to the argument value,

244+dividing the partition as equally as possible

245+

246+>>> printSQL $ ntile 5

247+ntile(5)

248+-}

249+ntile :: WinFun1 ('NotNull 'PGint4) ('NotNull 'PGint4)

250+ntile = unsafeWindowFunction1 "ntile"

251+

252+{- | returns value evaluated at the row that is offset rows before the current

253+row within the partition; if there is no such row, instead return default

254+(which must be of the same type as value). Both offset and default are

255+evaluated with respect to the current row.

256+-}

257+lag :: WinFunN '[ty, 'NotNull 'PGint4, ty] ty

258+lag = unsafeWindowFunctionN "lag"

259+

260+{- | returns value evaluated at the row that is offset rows after the current

261+row within the partition; if there is no such row, instead return default

262+(which must be of the same type as value). Both offset and default are

263+evaluated with respect to the current row.

264+-}

265+lead :: WinFunN '[ty, 'NotNull 'PGint4, ty] ty

266+lead = unsafeWindowFunctionN "lead"

267+

268+{- | returns value evaluated at the row that is the

269+first row of the window frame

270+-}

271+firstValue :: WinFun1 ty ty

272+firstValue = unsafeWindowFunction1 "first_value"

273+

274+{- | returns value evaluated at the row that is the

275+last row of the window frame

276+-}

277+lastValue :: WinFun1 ty ty

278+lastValue = unsafeWindowFunction1 "last_value"

279+

280+{- | returns value evaluated at the row that is the nth

281+row of the window frame (counting from 1); null if no such row

282+-}

283+nthValue :: WinFunN '[null ty, 'NotNull 'PGint4] ('Null ty)

284+nthValue = unsafeWindowFunctionN "nth_value"

squeal-postgresql/src/Squeal/PostgreSQL/List.hsnew file+112

@@ -0,0 +1,112 @@

1+{-|

2+Module: Squeal.PostgreSQL.List

3+Description: List related types and functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Haskell singly-linked lists are very powerful. This module

9+provides functionality for type-level lists, heterogeneous

10+lists and type aligned lists.

11+-}

12+

13+{-# LANGUAGE

14+ DataKinds

15+ , FlexibleContexts

16+ , GADTs

17+ , LambdaCase

18+ , MultiParamTypeClasses

19+ , OverloadedStrings

20+ , PolyKinds

21+ , QuantifiedConstraints

22+ , RankNTypes

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeFamilies

26+ , TypeOperators

27+ , UndecidableInstances

28+#-}

29+

30+module Squeal.PostgreSQL.List

31+ ( SOP.NP (..)

32+ , (*:)

33+ , Join

34+ , disjoin

35+ , Additional (..)

36+ , Path (..)

37+ , CFunctor (..)

38+ , CFoldable (..)

39+ , CFree (..)

40+ , Elem

41+ , In

42+ , Length

43+ ) where

44+

45+import Control.Category.Free

46+import Data.Function ((&))

47+import Data.Kind

48+import Data.Type.Bool

49+import GHC.TypeLits

50+

51+import Generics.SOP as SOP

52+

53+-- | `Join` is simply promoted `++` and is used in @JOIN@s in

54+-- `Squeal.PostgreSQL.Query.FromClause`s.

55+type family Join xs ys where

56+ Join '[] ys = ys

57+ Join (x ': xs) ys = x ': Join xs ys

58+

59+-- | `disjoin` is a utility function for splitting an `NP` list into pieces.

60+disjoin

61+ :: forall xs ys expr. SListI xs

62+ => NP expr (Join xs ys)

63+ -> (NP expr xs, NP expr ys)

64+disjoin = case sList @xs of

65+ SNil -> \ys -> (Nil, ys)

66+ SCons -> \(x :* xsys) ->

67+ case disjoin xsys of (xs,ys) -> (x :* xs, ys)

68+

69+-- | The `Additional` class is for appending

70+-- type-level list parameterized constructors such as `NP`,

71+-- `Squeal.PostgreSQL.Query.Selection`, and `Squeal.PostgreSQL.Query.FromClause`.

72+class Additional expr where

73+ also :: expr ys -> expr xs -> expr (Join xs ys)

74+instance Additional (NP expr) where

75+ also ys = \case

76+ Nil -> ys

77+ x :* xs -> x :* (xs & also ys)

78+

79+-- | A useful operator for ending an `NP` list of length at least 2 without `Nil`.

80+(*:) :: f x -> f y -> NP f '[x,y]

81+x *: y = x :* y :* Nil

82+infixl 9 *:

83+

84+-- | @Elem@ is a promoted `Data.List.elem`.

85+type family Elem x xs where

86+ Elem x '[] = 'False

87+ Elem x (x ': _) = 'True

88+ Elem x (_ ': x ': _) = 'True

89+ Elem x (_ ': _ ': x ': _) = 'True

90+ Elem x (_ ': _ ': _ ': x ': _) = 'True

91+ Elem x (_ ': _ ': _ ': _ ': x ': _) = 'True

92+ Elem x (_ ': _ ': _ ': _ ': _ ': x ': _) = 'True

93+ Elem x (_ ': xs) = Elem x xs

94+

95+-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.

96+type family In x xs :: Constraint where

97+ In x xs = If (Elem x xs) (() :: Constraint)

98+ (TypeError ('ShowType x ':<>: 'Text " is not in " ':<>: 'ShowType xs))

99+

100+{- | Calculate the `Length` of a type level list

101+

102+>>> :kind! Length '[Char,String,Bool,Double]

103+Length '[Char,String,Bool,Double] :: Nat

104+= 4

105+-}

106+type family Length (xs :: [k]) :: Nat where

107+ Length (_ ': _ ': _ ': _ ': _ : xs) = 5 + Length xs

108+ Length (_ ': _ ': _ ': _ : xs) = 4 + Length xs

109+ Length (_ ': _ ': _ : xs) = 3 + Length xs

110+ Length (_ ': _ : xs) = 2 + Length xs

111+ Length (_ : xs) = 1 + Length xs

112+ Length '[] = 0

squeal-postgresql/src/Squeal/PostgreSQL/Manipulation.hs+411−340

@@ -11,84 +11,139 @@ Squeal data manipulation language.

11{-# LANGUAGE

12 DeriveGeneric

13 , FlexibleContexts

14+ , FlexibleInstances

14 , GADTs

15 , GADTs

15 , GeneralizedNewtypeDeriving

16 , GeneralizedNewtypeDeriving

16 , LambdaCase

17 , LambdaCase

18+ , MultiParamTypeClasses

17 , OverloadedStrings

19 , OverloadedStrings

20+ , PatternSynonyms

21+ , QuantifiedConstraints

18 , RankNTypes

22 , RankNTypes

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeFamilies

19 , TypeInType

26 , TypeInType

20 , TypeOperators

27 , TypeOperators

28+ , UndecidableInstances

21#-}

29#-}

23module Squeal.PostgreSQL.Manipulation

31module Squeal.PostgreSQL.Manipulation

24 ( -- * Manipulation

32 ( -- * Manipulation

33+ Manipulation_

25− Manipulation (UnsafeManipulation, renderManipulation)

34+ , Manipulation (..)

26 , queryStatement

35 , queryStatement

27− , ColumnValue (..)

28− , ReturningClause (ReturningStar, Returning)

29− , ConflictClause (OnConflictDoRaise, OnConflictDoNothing, OnConflictDoUpdate)

30 -- * Insert

36 -- * Insert

31− , insertRows

37+ , insertInto

32− , insertRow

38+ , insertInto_

33− , insertRows_

34− , insertRow_

35− , insertQuery

36− , insertQuery_

37− , renderReturningClause

38− , renderConflictClause

39 -- * Update

40 , update

41 , update_

42 -- * Delete

43 , deleteFrom

44 , deleteFrom_

45− -- * With

45+ -- * Clauses

46− , with

46+ , Optional (..)

47+ , QueryClause (..)

48+ , pattern Values_

49+ , ReturningClause (..)

50+ , pattern Returning_

51+ , ConflictClause (..)

52+ , ConflictTarget (..)

53+ , ConflictAction (..)

54+ , UsingClause (..)

47 ) where

55 ) where

49import Control.DeepSeq

57import Control.DeepSeq

50import Data.ByteString hiding (foldr)

58import Data.ByteString hiding (foldr)

51−import Data.Monoid

59+import Data.Kind (Type)

53import qualified Generics.SOP as SOP

61import qualified Generics.SOP as SOP

54import qualified GHC.Generics as GHC

62import qualified GHC.Generics as GHC

64+import Squeal.PostgreSQL.Alias

56import Squeal.PostgreSQL.Expression

65import Squeal.PostgreSQL.Expression

66+import Squeal.PostgreSQL.Expression.Logic

67+import Squeal.PostgreSQL.List

68+import Squeal.PostgreSQL.PG

57import Squeal.PostgreSQL.Render

69import Squeal.PostgreSQL.Render

58import Squeal.PostgreSQL.Query

70import Squeal.PostgreSQL.Query

59import Squeal.PostgreSQL.Schema

71import Squeal.PostgreSQL.Schema

73+-- $setup

74+-- >>> import Squeal.PostgreSQL

75+-- >>> import Data.Int

76+-- >>> import Data.Time

77+

61{- |

78{- |

62A `Manipulation` is a statement which may modify data in the database,

79A `Manipulation` is a statement which may modify data in the database,

63−but does not alter the schema. Examples are inserts, updates and deletes.

80+but does not alter its schemas. Examples are inserts, updates and deletes.

64A `Query` is also considered a `Manipulation` even though it does not modify data.

81A `Query` is also considered a `Manipulation` even though it does not modify data.

83+The general `Manipulation` type is parameterized by

84+

85+* @commons :: FromType@ - scope for all `common` table expressions,

86+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

87+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

88+* @row :: RowType@ - return type of the `Query`.

89+-}

90+newtype Manipulation

91+ (commons :: FromType)

92+ (schemas :: SchemasType)

93+ (params :: [NullityType])

94+ (columns :: RowType)

95+ = UnsafeManipulation { renderManipulation :: ByteString }

96+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

97+instance RenderSQL (Manipulation commons schemas params columns) where

98+ renderSQL = renderManipulation

99+instance With Manipulation where

100+ with Done manip = manip

101+ with ctes manip = UnsafeManipulation $

102+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL manip

103+

104+{- |

105+The top level `Manipulation_` type is parameterized by a @schemas@ `SchemasType`,

106+against which the query is type-checked, an input @parameters@ Haskell `Type`,

107+and an ouput row Haskell `Type`.

108+

109+A top-level `Manipulation_` can be run

110+using `Squeal.PostgreSQL.PQ.manipulateParams`, or if @parameters = ()@

111+using `Squeal.PostgreSQL.PQ.manipulate`.

112+

113+Generally, @parameters@ will be a Haskell tuple or record whose entries

114+may be referenced using positional

115+`Squeal.PostgreSQL.Expression.Parameter.parameter`s and @row@ will be a

116+Haskell record, whose entries will be targeted using overloaded labels.

117+

118+>>> :set -XDeriveAnyClass -XDerivingStrategies

119+>>> :{

120+data Row a b = Row { col1 :: a, col2 :: b }

121+ deriving stock (GHC.Generic)

122+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

123+:}

124+

66simple insert:

125simple insert:

126

127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]

128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

68>>> :{

129>>> :{

69let

130let

70− manipulation :: Manipulation

131+ manipulation :: Manipulation_ (Public Schema) () ()

71− '[ "tab" ::: 'Table ('[] :=>

72− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

73− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[] '[]

74 manipulation =

132 manipulation =

75− insertRow_ #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)

133+ insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))

76in printSQL manipulation

134in printSQL manipulation

77:}

135:}

78INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)

136INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)

137

80parameterized insert:

138parameterized insert:

139

140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

82>>> :{

142>>> :{

83let

143let

84− manipulation :: Manipulation

144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()

85− '[ "tab" ::: 'Table ('[] :=>

86− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

87− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

88− '[ 'NotNull 'PGint4, 'NotNull 'PGint4 ] '[]

89 manipulation =

145 manipulation =

90− insertRow_ #tab

91− (Set (param @1) `As` #col1 :* Set (param @2) `As` #col2 :* Nil)

146+ insertInto_ #tab (Values_ (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2))

92in printSQL manipulation

147in printSQL manipulation

93:}

148:}

94INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))

149INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))

@@ -97,71 +152,48 @@ returning insert:

152

98>>> :{

153>>> :{

99let

154let

100− manipulation :: Manipulation

155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)

101− '[ "tab" ::: 'Table ('[] :=>

102− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

103− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[]

104− '["fromOnly" ::: 'NotNull 'PGint4]

105 manipulation =

156 manipulation =

106− insertRow #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)

157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))

107− OnConflictDoRaise (Returning (#col1 `As` #fromOnly :* Nil))

158+ OnConflictDoRaise (Returning (#col1 `as` #fromOnly))

108in printSQL manipulation

159in printSQL manipulation

109:}

160:}

110−INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT) RETURNING "col1" AS "fromOnly"

161+INSERT INTO "tab" ("col1", "col2") VALUES (2, 3) RETURNING "col1" AS "fromOnly"

111

162

112upsert:

163upsert:

113

164

165+>>> type CustomersColumns = '["name" ::: 'NoDef :=> 'NotNull 'PGtext, "email" ::: 'NoDef :=> 'NotNull 'PGtext]

166+>>> type CustomersConstraints = '["uq" ::: 'Unique '["name"]]

167+>>> type CustomersSchema = '["customers" ::: 'Table (CustomersConstraints :=> CustomersColumns)]

114>>> :{

168>>> :{

115let

169let

116− manipulation :: Manipulation

170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()

117− '[ "tab" ::: 'Table ('[] :=>

118− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

119− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

120− '[] '[ "sum" ::: 'NotNull 'PGint4]

121 manipulation =

171 manipulation =

122− insertRows #tab

172+ insertInto #customers

123− (Set 2 `As` #col1 :* Set 4 `As` #col2 :* Nil)

173+ (Values_ (Set "John Smith" `as` #name :* Set "john@smith.com" `as` #email))

124− [Set 6 `As` #col1 :* Set 8 `As` #col2 :* Nil]

174+ (OnConflict (OnConstraint #uq)

125− (OnConflictDoUpdate

175+ (DoUpdate (Set (#excluded ! #email <> "; " <> #customers ! #email) `as` #email) []))

126− (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

176+ (Returning_ Nil)

127− [#col1 .== #col2])

128− (Returning $ (#col1 + #col2) `As` #sum :* Nil)

129in printSQL manipulation

177in printSQL manipulation

130:}

178:}

131−INSERT INTO "tab" ("col1", "col2") VALUES (2, 4), (6, 8) ON CONFLICT DO UPDATE SET "col1" = 2 WHERE ("col1" = "col2") RETURNING ("col1" + "col2") AS "sum"

179+INSERT INTO "customers" ("name", "email") VALUES (E'John Smith', E'john@smith.com') ON CONFLICT ON CONSTRAINT "uq" DO UPDATE SET "email" = ("excluded"."email" || (E'; ' || "customers"."email"))

132

180

133query insert:

181query insert:

134

182

135>>> :{

183>>> :{

136let

184let

137− manipulation :: Manipulation

185+ manipulation :: Manipulation_ (Public Schema) () ()

138− '[ "tab" ::: 'Table ('[] :=>

186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))

139− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

140− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

141− ])

142− , "other_tab" ::: 'Table ('[] :=>

143− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

144− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

145− ])

146− ] '[] '[]

147− manipulation =

148− insertQuery_ #tab

149− (selectStar (from (table (#other_tab `As` #t))))

150in printSQL manipulation

187in printSQL manipulation

151:}

188:}

152−INSERT INTO "tab" SELECT * FROM "other_tab" AS "t"

189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"

153

190

154update:

191update:

155

192

156>>> :{

193>>> :{

157let

194let

158− manipulation :: Manipulation

195+ manipulation :: Manipulation_ (Public Schema) () ()

159− '[ "tab" ::: 'Table ('[] :=>

160− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

161− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[] '[]

162− manipulation =

163− update_ #tab (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)

164− (#col1 ./= #col2)

165in printSQL manipulation

197in printSQL manipulation

166:}

198:}

167UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")

199UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")

@@ -170,154 +202,178 @@ delete:

170

202

171>>> :{

203>>> :{

172let

204let

173− manipulation :: Manipulation

205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)

174− '[ "tab" ::: 'Table ('[] :=>

175− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

176− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[]

177− '[ "col1" ::: 'NotNull 'PGint4

178− , "col2" ::: 'NotNull 'PGint4 ]

179− manipulation = deleteFrom #tab (#col1 .== #col2) ReturningStar

206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)

180in printSQL manipulation

207in printSQL manipulation

181:}

208:}

182DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *

209DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *

183−-}

184−newtype Manipulation

185− (schema :: SchemaType)

186− (params :: [NullityType])

187− (columns :: RelationType)

188− = UnsafeManipulation { renderManipulation :: ByteString }

189− deriving (GHC.Generic,Show,Eq,Ord,NFData)

190

210

191−instance RenderSQL (Manipulation schema params columns) where

211+delete and using clause:

192− renderSQL = renderManipulation

212+

213+>>> :{

214+type Schema3 =

215+ '[ "tab" ::: 'Table ('[] :=> Columns)

216+ , "other_tab" ::: 'Table ('[] :=> Columns)

217+ , "third_tab" ::: 'Table ('[] :=> Columns) ]

218+:}

219+

220+>>> :{

221+let

222+ manipulation :: Manipulation_ (Public Schema3) () ()

223+ manipulation =

224+ deleteFrom #tab (Using (table #other_tab & also (table #third_tab)))

225+ ( (#tab ! #col2 .== #other_tab ! #col2)

226+ .&& (#tab ! #col2 .== #third_tab ! #col2) )

227+ (Returning_ Nil)

228+in printSQL manipulation

229+:}

230+DELETE FROM "tab" USING "other_tab" AS "other_tab", "third_tab" AS "third_tab" WHERE (("tab"."col2" = "other_tab"."col2") AND ("tab"."col2" = "third_tab"."col2"))

231+

232+with manipulation:

233+

234+>>> type ProductsColumns = '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

235+>>> type ProductsSchema = '["products" ::: 'Table ('[] :=> ProductsColumns), "products_deleted" ::: 'Table ('[] :=> ProductsColumns)]

236+>>> :{

237+let

238+ manipulation :: Manipulation_ (Public ProductsSchema) (Only Day) ()

239+ manipulation = with

240+ (deleteFrom #products NoUsing (#date .< param @1) (Returning Star) `as` #del)

241+ (insertInto_ #products_deleted (Subquery (select Star (from (common #del)))))

242+in printSQL manipulation

243+:}

244+WITH "del" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "del" AS "del"

245+-}

246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where

247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)

193

248

194-- | Convert a `Query` into a `Manipulation`.

249-- | Convert a `Query` into a `Manipulation`.

195queryStatement

250queryStatement

196− :: Query schema params columns

251+ :: Query '[] commons schemas params columns

252+ -- ^ `Query` to embed as a `Manipulation`

197− -> Manipulation schema params columns

253+ -> Manipulation commons schemas params columns

198−queryStatement q = UnsafeManipulation $ renderQuery q

254+queryStatement q = UnsafeManipulation $ renderSQL q

199

255

200{-----------------------------------------

256{-----------------------------------------

201INSERT statements

257INSERT statements

202-----------------------------------------}

258-----------------------------------------}

203

259

204−-- | Insert multiple rows.

260+{- |

205−--

206−-- When a table is created, it contains no data. The first thing to do

261+When a table is created, it contains no data. The first thing to do

207−-- before a database can be of much use is to insert data. Data is

262+before a database can be of much use is to insert data. Data is

208−-- conceptually inserted one row at a time. Of course you can also insert

263+conceptually inserted one row at a time. Of course you can also insert

209−-- more than one row, but there is no way to insert less than one row.

264+more than one row, but there is no way to insert less than one row.

210−-- Even if you know only some column values, a complete row must be created.

265+Even if you know only some column values, a complete row must be created.

211−insertRows

266+-}

212− :: ( SOP.SListI columns

267+insertInto

213− , SOP.SListI results

268+ :: ( Has sch schemas schema

214− , Has tab schema ('Table table)

215− , columns ~ TableToColumns table )

216− => Alias tab -- ^ table to insert into

217− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

218− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

219− -> ConflictClause schema columns params

220− -- ^ what to do in case of constraint conflict

221− -> ReturningClause schema columns params results -- ^ results to return

222− -> Manipulation schema params results

223−insertRows tab rw rws conflict returning = UnsafeManipulation $

224− "INSERT" <+> "INTO" <+> renderAlias tab

225− <+> parenthesized (renderCommaSeparated renderAliasPart rw)

226− <+> "VALUES"

227− <+> commaSeparated

228− ( parenthesized

229− . renderCommaSeparated renderColumnValuePart <$> rw:rws )

230− <> renderConflictClause conflict

231− <> renderReturningClause returning

232− where

233− renderAliasPart, renderColumnValuePart

234− :: Aliased (ColumnValue schema '[] params) ty -> ByteString

235− renderAliasPart (_ `As` name) = renderAlias name

236− renderColumnValuePart (value `As` _) = case value of

237− Default -> "DEFAULT"

238− Set expression -> renderExpression expression

239−

240−-- | Insert a single row.

241−insertRow

242− :: ( SOP.SListI columns

243− , SOP.SListI results

244− , Has tab schema ('Table table)

245− , columns ~ TableToColumns table )

246− => Alias tab -- ^ table to insert into

247− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

248− -> ConflictClause schema columns params

249− -- ^ what to do in case of constraint conflict

250− -> ReturningClause schema columns params results -- ^ results to return

251− -> Manipulation schema params results

252−insertRow tab rw = insertRows tab rw []

253−

254−-- | Insert multiple rows returning `Nil` and raising an error on conflicts.

255−insertRows_

256− :: ( SOP.SListI columns

257− , Has tab schema ('Table table)

258− , columns ~ TableToColumns table )

259− => Alias tab -- ^ table to insert into

260− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

261− -> [NP (Aliased (ColumnValue schema '[] params)) columns] -- ^ more rows to insert

262− -> Manipulation schema params '[]

263−insertRows_ tab rw rws =

264− insertRows tab rw rws OnConflictDoRaise (Returning Nil)

265−

266−-- | Insert a single row returning `Nil` and raising an error on conflicts.

267−insertRow_

268− :: ( SOP.SListI columns

269− , Has tab schema ('Table table)

270− , columns ~ TableToColumns table )

271− => Alias tab -- ^ table to insert into

272− -> NP (Aliased (ColumnValue schema '[] params)) columns -- ^ row to insert

273− -> Manipulation schema params '[]

274−insertRow_ tab rw = insertRow tab rw OnConflictDoRaise (Returning Nil)

275−

276−-- | Insert a `Query`.

277−insertQuery

278− :: ( SOP.SListI columns

279− , SOP.SListI results

280 , Has tab schema ('Table table)

269 , Has tab schema ('Table table)

281− , columns ~ TableToColumns table )

270+ , columns ~ TableToColumns table

271+ , row0 ~ TableToRow table

272+ , SOP.SListI columns

273+ , SOP.SListI row1 )

274+ => QualifiedAlias sch tab

275+ -- ^ table

276+ -> QueryClause commons schemas params columns

282− => Alias tab -- ^ table to insert into

277+ -- ^ what to insert

283− -> Query schema params (ColumnsToRelation columns)

284− -> ConflictClause schema columns params

278+ -> ConflictClause tab commons schemas params table

285− -- ^ what to do in case of constraint conflict

279+ -- ^ what to do in case of conflict

286− -> ReturningClause schema columns params results -- ^ results to return

280+ -> ReturningClause commons schemas params '[tab ::: row0] row1

281+ -- ^ what to return

287− -> Manipulation schema params results

282+ -> Manipulation commons schemas params row1

288−insertQuery tab query conflict returning = UnsafeManipulation $

283+insertInto tab qry conflict ret = UnsafeManipulation $

289− "INSERT" <+> "INTO" <+> renderAlias tab

284+ "INSERT" <+> "INTO" <+> renderSQL tab

290− <+> renderQuery query

285+ <+> renderSQL qry

291− <> renderConflictClause conflict

286+ <> renderSQL conflict

292− <> renderReturningClause returning

287+ <> renderSQL ret

293−

288+

294−-- | Insert a `Query` returning `Nil` and raising an error on conflicts.

289+-- | Like `insertInto` but with `OnConflictDoRaise` and `no` `ReturningClause`.

295−insertQuery_

290+insertInto_

296− :: ( SOP.SListI columns

291+ :: ( Has sch schemas schema

297 , Has tab schema ('Table table)

292 , Has tab schema ('Table table)

298− , columns ~ TableToColumns table )

293+ , columns ~ TableToColumns table

299− => Alias tab -- ^ table to insert into

294+ , row ~ TableToRow table

300− -> Query schema params (ColumnsToRelation columns)

295+ , SOP.SListI columns )

296+ => QualifiedAlias sch tab

297+ -- ^ table

298+ -> QueryClause commons schemas params columns

299+ -- ^ what to insert

301− -> Manipulation schema params '[]

300+ -> Manipulation commons schemas params '[]

302−insertQuery_ tab query =

301+insertInto_ tab qry =

303− insertQuery tab query OnConflictDoRaise (Returning Nil)

302+ insertInto tab qry OnConflictDoRaise (Returning_ Nil)

304−

303+

305−-- | `ColumnValue`s are values to insert or update in a row.

304+-- | A `QueryClause` describes what to `insertInto` a table.

306−-- `Same` updates with the same value.

305+data QueryClause commons schemas params columns where

307−-- `Default` inserts or updates with the @DEFAULT@ value.

306+ Values

308−-- `Set` sets a value to be an `Expression`, which can refer to

307+ :: SOP.SListI columns

309−-- existing value in the row for an update.

308+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

310−data ColumnValue

309+ -- ^ row of values

311− (schema :: SchemaType)

310+ -> [NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns]

312− (columns :: RelationType)

311+ -- ^ additional rows of values

313− (params :: [NullityType])

312+ -> QueryClause commons schemas params columns

314− (ty :: ColumnType)

313+ Select

315− where

314+ :: SOP.SListI columns

316− Same :: ColumnValue schema (column ': columns) params ty

315+ => NP (Aliased (Optional (Expression '[] commons grp schemas params from))) columns

317− Default :: ColumnValue schema columns params ('Def :=> ty)

316+ -- ^ row of values

318− Set

317+ -> TableExpression '[] commons grp schemas params from

319− :: (forall table. Expression schema '[table ::: columns] 'Ungrouped params ty)

318+ -- ^ from a table expression

320− -> ColumnValue schema columns params (constraint :=> ty)

319+ -> QueryClause commons schemas params columns

320+ Subquery

321+ :: ColumnsToRow columns ~ row

322+ => Query '[] commons schemas params row

323+ -- ^ subquery to insert

324+ -> QueryClause commons schemas params columns

325+

326+instance RenderSQL (QueryClause commons schemas params columns) where

327+ renderSQL = \case

328+ Values row0 rows ->

329+ parenthesized (renderCommaSeparated renderSQLPart row0)

330+ <+> "VALUES"

331+ <+> commaSeparated

332+ ( parenthesized

333+ . renderCommaSeparated renderValuePart <$> row0 : rows )

334+ Select row0 tab ->

335+ parenthesized (renderCommaSeparatedMaybe renderSQLPartMaybe row0)

336+ <+> "SELECT"

337+ <+> renderCommaSeparatedMaybe renderValuePartMaybe row0

338+ <+> renderSQL tab

339+ Subquery qry -> renderQuery qry

340+ where

341+ renderSQLPartMaybe, renderValuePartMaybe

342+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

343+ -> Maybe ByteString

344+ renderSQLPartMaybe = \case

345+ Default `As` _ -> Nothing

346+ Set _ `As` name -> Just $ renderSQL name

347+ renderValuePartMaybe = \case

348+ Default `As` _ -> Nothing

349+ Set value `As` _ -> Just $ renderExpression value

350+ renderSQLPart, renderValuePart

351+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

352+ -> ByteString

353+ renderSQLPart (_ `As` name) = renderSQL name

354+ renderValuePart (value `As` _) = renderSQL value

355+

356+-- | `Values_` describes a single `NP` list of `Aliased` `Optional` `Expression`s

357+-- whose `ColumnsType` must match the tables'.

358+pattern Values_

359+ :: SOP.SListI columns

360+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

361+ -- ^ row of values

362+ -> QueryClause commons schemas params columns

363+pattern Values_ vals = Values vals []

364+

365+-- | `Optional` is either `Default` or a value, parameterized by an appropriate

366+-- `ColumnConstraint`.

367+data Optional expr ty where

368+ -- | Use the `Default` value for a column.

369+ Default :: Optional expr ('Def :=> ty)

370+ -- | `Set` a value for a column.

371+ Set :: expr ty -> Optional expr (def :=> ty)

372+

373+instance (forall x. RenderSQL (expr x)) => RenderSQL (Optional expr ty) where

374+ renderSQL = \case

375+ Default -> "DEFAULT"

376+ Set expr -> renderSQL expr

321

377

322-- | A `ReturningClause` computes and return value(s) based

378-- | A `ReturningClause` computes and return value(s) based

323-- on each row actually inserted, updated or deleted. This is primarily

379-- on each row actually inserted, updated or deleted. This is primarily

@@ -325,72 +381,100 @@ data ColumnValue

325-- serial sequence number. However, any expression using the table's columns

381-- serial sequence number. However, any expression using the table's columns

326-- is allowed. Only rows that were successfully inserted or updated or

382-- is allowed. Only rows that were successfully inserted or updated or

327-- deleted will be returned. For example, if a row was locked

383-- deleted will be returned. For example, if a row was locked

328−-- but not updated because an `OnConflictDoUpdate` condition was not satisfied,

384+-- but not updated because an `OnConflict` `DoUpdate` condition was not satisfied,

329−-- the row will not be returned. `ReturningStar` will return all columns

385+-- the row will not be returned. `Returning` `Star` will return all columns

330−-- in the row. Use @Returning Nil@ in the common case where no return

386+-- in the row. Use `Returning` `Nil` in the common case where no return

331-- values are desired.

387-- values are desired.

332−data ReturningClause

388+newtype ReturningClause commons schemas params from row =

333− (schema :: SchemaType)

389+ Returning (Selection '[] commons 'Ungrouped schemas params from row)

334− (columns :: ColumnsType)

390+

335− (params :: [NullityType])

391+instance RenderSQL (ReturningClause commons schemas params from row) where

336− (results :: RelationType)

392+ renderSQL = \case

337− where

338− ReturningStar

339− :: results ~ ColumnsToRelation columns

340− => ReturningClause schema columns params results

341− Returning

342− :: rel ~ ColumnsToRelation columns

343− => NP (Aliased (Expression schema '[table ::: rel] 'Ungrouped params)) results

344− -> ReturningClause schema columns params results

345−

346−-- | Render a `ReturningClause`.

347−renderReturningClause

348− :: SOP.SListI results

349− => ReturningClause schema params columns results

350− -> ByteString

351−renderReturningClause = \case

352− ReturningStar -> " RETURNING *"

353− Returning Nil -> ""

393+ Returning (List Nil) -> ""

354− Returning results -> " RETURNING"

394+ Returning selection -> " RETURNING" <+> renderSQL selection

355− <+> renderCommaSeparated (renderAliasedAs renderExpression) results

395+

396+-- | `Returning` a `List`

397+pattern Returning_

398+ :: SOP.SListI row

399+ => NP (Aliased (Expression '[] commons 'Ungrouped schemas params from)) row

400+ -- ^ row of values

401+ -> ReturningClause commons schemas params from row

402+pattern Returning_ list = Returning (List list)

356

403

357-- | A `ConflictClause` specifies an action to perform upon a constraint

404-- | A `ConflictClause` specifies an action to perform upon a constraint

358-- violation. `OnConflictDoRaise` will raise an error.

405-- violation. `OnConflictDoRaise` will raise an error.

359−-- `OnConflictDoNothing` simply avoids inserting a row.

406+-- `OnConflict` `DoNothing` simply avoids inserting a row.

360−-- `OnConflictDoUpdate` updates the existing row that conflicts with the row

407+-- `OnConflict` `DoUpdate` updates the existing row that conflicts with the row

361-- proposed for insertion.

408-- proposed for insertion.

362−data ConflictClause (schema :: SchemaType) (columns :: ColumnsType) params where

409+data ConflictClause tab commons schemas params table where

363− OnConflictDoRaise :: ConflictClause schema columns params

410+ OnConflictDoRaise :: ConflictClause tab commons schemas params table

364− OnConflictDoNothing :: ConflictClause schema columns params

411+ OnConflict

365− OnConflictDoUpdate

412+ :: ConflictTarget constraints

366− :: NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

413+ -- ^ conflict target

367− -> [Condition schema '[table ::: ColumnsToRelation columns] 'Ungrouped params]

414+ -> ConflictAction tab commons schemas params columns

415+ -- ^ conflict action

368− -> ConflictClause schema columns params

416+ -> ConflictClause tab commons schemas params (constraints :=> columns)

369

417

370-- | Render a `ConflictClause`.

418-- | Render a `ConflictClause`.

371−renderConflictClause

419+instance SOP.SListI (TableToColumns table)

372− :: SOP.SListI columns

420+ => RenderSQL (ConflictClause tab commons schemas params table) where

373− => ConflictClause schema columns params

421+ renderSQL = \case

422+ OnConflictDoRaise -> ""

423+ OnConflict target action -> " ON CONFLICT"

424+ <+> renderSQL target <+> renderSQL action

425+

426+{- |

427+`ConflictAction` specifies an alternative `OnConflict` action.

428+It can be either `DoNothing`, or a `DoUpdate` clause specifying

429+the exact details of the `update` action to be performed in case of a conflict.

430+The `Set` and WHERE `Condition`s in `OnConflict` `DoUpdate` have access to the

431+existing row using the table's name (or an alias), and to rows proposed

432+for insertion using the special @#excluded@ table.

433+`OnConflict` `DoNothing` simply avoids inserting a row as its alternative action.

434+`OnConflict` `DoUpdate` updates the existing row that conflicts

435+with the row proposed for insertion as its alternative action.

436+-}

437+data ConflictAction tab commons schemas params columns where

438+ DoNothing :: ConflictAction tab commons schemas params columns

439+ DoUpdate

440+ :: ( row ~ ColumnsToRow columns

441+ , SOP.SListI columns

442+ , columns ~ (col0 ': cols)

443+ , SOP.All (HasIn columns) subcolumns

444+ , AllUnique subcolumns )

445+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]))) subcolumns

446+ -> [Condition '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]]

447+ -- ^ WHERE `Condition`s

448+ -> ConflictAction tab commons schemas params columns

449+

450+instance RenderSQL (ConflictAction tab commons schemas params columns) where

451+ renderSQL = \case

452+ DoNothing -> "DO NOTHING"

453+ DoUpdate updates whs'

454+ -> "DO UPDATE SET"

455+ <+> renderCommaSeparated renderUpdate updates

456+ <> case whs' of

457+ [] -> ""

458+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

459+

460+renderUpdate

461+ :: (forall x. RenderSQL (expr x))

462+ => Aliased (Optional expr) ty

374 -> ByteString

463 -> ByteString

375−renderConflictClause = \case

464+renderUpdate (expr `As` col) = renderSQL col <+> "=" <+> renderSQL expr

376− OnConflictDoRaise -> ""

465+

377− OnConflictDoNothing -> " ON CONFLICT DO NOTHING"

466+-- | A `ConflictTarget` specifies the constraint violation that triggers a

378− OnConflictDoUpdate updates whs'

467+-- `ConflictAction`.

379− -> " ON CONFLICT DO UPDATE SET"

468+data ConflictTarget constraints where

380− <+> renderCommaSeparatedMaybe renderUpdate updates

469+ OnConstraint

381− <> case whs' of

470+ :: Has con constraints constraint

382− [] -> ""

471+ => Alias con

383− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

472+ -> ConflictTarget constraints

384− where

473+

385− renderUpdate

474+-- | Render a `ConflictTarget`

386− :: Aliased (ColumnValue schema columns params) column

475+instance RenderSQL (ConflictTarget constraints) where

387− -> Maybe ByteString

476+ renderSQL (OnConstraint con) =

388− renderUpdate = \case

477+ "ON" <+> "CONSTRAINT" <+> renderSQL con

389− Same `As` _ -> Nothing

390− Default `As` column -> Just $

391− renderAlias column <+> "=" <+> "DEFAULT"

392− Set expression `As` column -> Just $

393− renderAlias column <+> "=" <+> renderExpression expression

394

478

395{-----------------------------------------

479{-----------------------------------------

396UPDATE statements

480UPDATE statements

@@ -400,108 +484,95 @@ UPDATE statements

400-- in all rows that satisfy the condition.

484-- in all rows that satisfy the condition.

401update

485update

402 :: ( SOP.SListI columns

486 :: ( SOP.SListI columns

403− , SOP.SListI results

487+ , SOP.SListI row1

488+ , Has sch schemas schema

404 , Has tab schema ('Table table)

489 , Has tab schema ('Table table)

490+ , row0 ~ TableToRow table

405− , columns ~ TableToColumns table )

491+ , columns ~ TableToColumns table

492+ , SOP.All (HasIn columns) subcolumns

493+ , AllUnique subcolumns )

406− => Alias tab -- ^ table to update

494+ => QualifiedAlias sch tab -- ^ table to update

407− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

495+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row0]))) subcolumns

408 -- ^ modified values to replace old values

496 -- ^ modified values to replace old values

409− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

497+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row0]

410 -- ^ condition under which to perform update on a row

498 -- ^ condition under which to perform update on a row

411− -> ReturningClause schema columns params results -- ^ results to return

499+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

412− -> Manipulation schema params results

500+ -> Manipulation commons schemas params row1

413update tab columns wh returning = UnsafeManipulation $

501update tab columns wh returning = UnsafeManipulation $

414 "UPDATE"

502 "UPDATE"

415− <+> renderAlias tab

503+ <+> renderSQL tab

416 <+> "SET"

504 <+> "SET"

417− <+> renderCommaSeparatedMaybe renderUpdate columns

505+ <+> renderCommaSeparated renderUpdate columns

418− <+> "WHERE" <+> renderExpression wh

506+ <+> "WHERE" <+> renderSQL wh

419− <> renderReturningClause returning

507+ <> renderSQL returning

420− where

421− renderUpdate

422− :: Aliased (ColumnValue schema columns params) column

423− -> Maybe ByteString

424− renderUpdate = \case

425− Same `As` _ -> Nothing

426− Default `As` column -> Just $

427− renderAlias column <+> "=" <+> "DEFAULT"

428− Set expression `As` column -> Just $

429− renderAlias column <+> "=" <+> renderExpression expression

430

508

431-- | Update a row returning `Nil`.

509-- | Update a row returning `Nil`.

432update_

510update_

433 :: ( SOP.SListI columns

511 :: ( SOP.SListI columns

512+ , Has sch schemas schema

434 , Has tab schema ('Table table)

513 , Has tab schema ('Table table)

514+ , row ~ TableToRow table

435− , columns ~ TableToColumns table )

515+ , columns ~ TableToColumns table

516+ , SOP.All (HasIn columns) subcolumns

517+ , AllUnique subcolumns )

436− => Alias tab -- ^ table to update

518+ => QualifiedAlias sch tab -- ^ table to update

437− -> NP (Aliased (ColumnValue schema (ColumnsToRelation columns) params)) columns

519+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row]))) subcolumns

438 -- ^ modified values to replace old values

520 -- ^ modified values to replace old values

439− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

521+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

440 -- ^ condition under which to perform update on a row

522 -- ^ condition under which to perform update on a row

441− -> Manipulation schema params '[]

523+ -> Manipulation commons schemas params '[]

442−update_ tab columns wh = update tab columns wh (Returning Nil)

524+update_ tab columns wh = update tab columns wh (Returning_ Nil)

443

525

444{-----------------------------------------

526{-----------------------------------------

445DELETE statements

527DELETE statements

446-----------------------------------------}

528-----------------------------------------}

447

529

530+-- | Specify additional tables with `Using`

531+-- an `also` list of table expressions, allowing columns

532+-- from other tables to appear in the WHERE condition.

533+-- This is similar to the list of tables that can be specified

534+-- in the FROM Clause of a SELECT statement;

535+-- for example, an alias for the table name can be specified.

536+-- Do not repeat the target table in the `Using` list,

537+-- unless you wish to set up a self-join.

538+-- `NoUsing` if no additional tables are to be used.

539+data UsingClause commons schemas params from where

540+ NoUsing :: UsingClause commons schemas params '[]

541+ Using

542+ :: FromClause '[] commons schemas params from

543+ -- ^ what to use

544+ -> UsingClause commons schemas params from

545+

448−-- | Delete rows of a table.

546+-- | Delete rows from a table.

449deleteFrom

547deleteFrom

450− :: ( SOP.SListI results

548+ :: ( SOP.SListI row1

549+ , Has sch schemas schema

451 , Has tab schema ('Table table)

550 , Has tab schema ('Table table)

551+ , row0 ~ TableToRow table

452 , columns ~ TableToColumns table )

552 , columns ~ TableToColumns table )

453− => Alias tab -- ^ table to delete from

553+ => QualifiedAlias sch tab -- ^ table to delete from

554+ -> UsingClause commons schemas params from

454− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

555+ -> Condition '[] commons 'Ungrouped schemas params (tab ::: row0 ': from)

455 -- ^ condition under which to delete a row

556 -- ^ condition under which to delete a row

456− -> ReturningClause schema columns params results -- ^ results to return

557+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

457− -> Manipulation schema params results

558+ -> Manipulation commons schemas params row1

458−deleteFrom tab wh returning = UnsafeManipulation $

559+deleteFrom tab using wh returning = UnsafeManipulation $

459− "DELETE FROM" <+> renderAlias tab

560+ "DELETE FROM"

460− <+> "WHERE" <+> renderExpression wh

561+ <+> renderSQL tab

461− <> renderReturningClause returning

562+ <> case using of

563+ NoUsing -> ""

564+ Using tables -> " USING" <+> renderSQL tables

565+ <+> "WHERE" <+> renderSQL wh

566+ <> renderSQL returning

462

567

463-- | Delete rows returning `Nil`.

568-- | Delete rows returning `Nil`.

464deleteFrom_

569deleteFrom_

570+ :: ( Has sch schemas schema

465− :: ( Has tab schema ('Table table)

571+ , Has tab schema ('Table table)

572+ , row ~ TableToRow table

466 , columns ~ TableToColumns table )

573 , columns ~ TableToColumns table )

467− => Alias tab -- ^ table to delete from

574+ => QualifiedAlias sch tab -- ^ table to delete from

468− -> Condition schema '[tab ::: ColumnsToRelation columns] 'Ungrouped params

575+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

469 -- ^ condition under which to delete a row

576 -- ^ condition under which to delete a row

470− -> Manipulation schema params '[]

577+ -> Manipulation commons schemas params '[]

471−deleteFrom_ tab wh = deleteFrom tab wh (Returning Nil)

578+deleteFrom_ tab wh = deleteFrom tab NoUsing wh (Returning_ Nil)

472−

473−{-----------------------------------------

474−WITH statements

475−-----------------------------------------}

476−

477−-- | `with` provides a way to write auxiliary statements for use in a larger statement.

478−-- These statements, which are often referred to as Common Table Expressions or CTEs,

479−-- can be thought of as defining temporary tables that exist just for one statement.

480−--

481−-- >>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

482−--

483−-- >>> :{

484−-- let

485−-- manipulation :: Manipulation '["products" ::: 'Table ProductsTable, "products_deleted" ::: 'Table ProductsTable] '[ 'NotNull 'PGdate] '[]

486−-- manipulation = with

487−-- (deleteFrom #products (#date .< param @1) ReturningStar `As` #deleted_rows :* Nil)

488−-- (insertQuery_ #products_deleted (selectStar (from (view (#deleted_rows `As` #t)))))

489−-- in printSQL manipulation

490−-- :}

491−-- WITH "deleted_rows" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "deleted_rows" AS "t"

492−with

493− :: SOP.SListI commons

494− => NP (Aliased (Manipulation schema params)) commons

495− -- ^ common table expressions

496− -> Manipulation (With commons schema) params results

497− -> Manipulation schema params results

498−with commons manipulation = UnsafeManipulation $

499− "WITH" <+> renderCommaSeparated renderCommon commons

500− <+> renderManipulation manipulation

501− where

502− renderCommon

503− :: Aliased (Manipulation schema params) common

504− -> ByteString

505− renderCommon (common `As` alias) =

506− renderAlias alias <+> "AS" <+>

507− parenthesized (renderManipulation common)

squeal-postgresql/src/Squeal/PostgreSQL/Migration.hs+347−215

@@ -8,8 +8,13 @@ Stability: experimental

8This module defines a `Migration` type to safely

9change the schema of your database over time. Let's see an example!

11+First turn on some extensions.

12+

11>>> :set -XDataKinds -XOverloadedLabels

13>>> :set -XDataKinds -XOverloadedLabels

12>>> :set -XOverloadedStrings -XFlexibleContexts -XTypeOperators

14>>> :set -XOverloadedStrings -XFlexibleContexts -XTypeOperators

15+

16+Next, let's define our `TableType`s.

17+

13>>> :{

18>>> :{

14type UsersTable =

19type UsersTable =

15 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

20 '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

@@ -20,7 +25,7 @@ type UsersTable =

21>>> :{

26>>> :{

22type EmailsTable =

27type EmailsTable =

23− '[ "pk_emails" ::: 'PrimaryKey '["id"]

28+ '[ "pk_emails" ::: 'PrimaryKey '["id"]

24 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

29 , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

25 ] :=>

30 ] :=>

26 '[ "id" ::: 'Def :=> 'NotNull 'PGint4

31 '[ "id" ::: 'Def :=> 'NotNull 'PGint4

@@ -29,248 +34,293 @@ type EmailsTable =

29 ]

34 ]

30:}

35:}

37+Now we can define some `Migration`s to make our tables.

38+

32>>> :{

39>>> :{

33let

40let

34− makeUsers :: Migration IO '[] '["users" ::: 'Table UsersTable]

41+ makeUsers :: Migration Definition (Public '[]) '["public" ::: '["users" ::: 'Table UsersTable]]

35 makeUsers = Migration

42 makeUsers = Migration

36 { name = "make users table"

43 { name = "make users table"

37− , up = void . define $

38− createTable #users

44+ , up = createTable #users

39− ( serial `As` #id :*

45+ ( serial `as` #id :*

40− (text & notNullable) `As` #name :* Nil )

46+ notNullable text `as` #name )

41− ( primaryKey #id `As` #pk_users :* Nil )

47+ ( primaryKey #id `as` #pk_users )

42− , down = void . define $ dropTable #users

48+ , down = dropTable #users

43 }

49 }

44:}

50:}

46>>> :{

52>>> :{

47let

53let

48− makeEmails :: Migration IO '["users" ::: 'Table UsersTable]

54+ makeEmails :: Migration Definition '["public" ::: '["users" ::: 'Table UsersTable]]

49− '["users" ::: 'Table UsersTable, "emails" ::: 'Table EmailsTable]

55+ '["public" ::: '["users" ::: 'Table UsersTable, "emails" ::: 'Table EmailsTable]]

50 makeEmails = Migration

56 makeEmails = Migration

51 { name = "make emails table"

57 { name = "make emails table"

52− , up = void . define $

53− createTable #emails

58+ , up = createTable #emails

54− ( serial `As` #id :*

59+ ( serial `as` #id :*

55− (int & notNullable) `As` #user_id :*

60+ notNullable int `as` #user_id :*

56− (text & nullable) `As` #email :* Nil )

61+ nullable text `as` #email )

57− ( primaryKey #id `As` #pk_emails :*

62+ ( primaryKey #id `as` #pk_emails :*

58 foreignKey #user_id #users #id

63 foreignKey #user_id #users #id

59− OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

64+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

60− , down = void . define $ dropTable #emails

65+ , down = dropTable #emails

61 }

66 }

62:}

67:}

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`.

66>>> let migrations = makeUsers :>> makeEmails :>> Done

71>>> let migrations = makeUsers :>> makeEmails :>> Done

68−>>> :{

73+Now run the migrations.

69−let

70− numMigrations

71− :: Has "schema_migrations" schema ('Table MigrationsTable)

72− => PQ schema schema IO ()

73− numMigrations = do

74− result <- runQuery (selectStar (from (table (#schema_migrations `As` #m))))

75− num <- ntuples result

76− liftBase $ print num

77−:}

75+>>> import Control.Monad.IO.Class

79>>> :{

76>>> :{

80withConnection "host=localhost port=5432 dbname=exampledb" $

77withConnection "host=localhost port=5432 dbname=exampledb" $

81 manipulate (UnsafeManipulation "SET client_min_messages TO WARNING;")

78 manipulate (UnsafeManipulation "SET client_min_messages TO WARNING;")

82 -- suppress notices

79 -- suppress notices

80+ & pqThen (liftIO (putStrLn "Migrate"))

83 & pqThen (migrateUp migrations)

81 & pqThen (migrateUp migrations)

84− & pqThen numMigrations

82+ & pqThen (liftIO (putStrLn "Rollback"))

85 & pqThen (migrateDown migrations)

83 & pqThen (migrateDown migrations)

86− & pqThen numMigrations

87:}

84:}

88−Row 2

85+Migrate

89−Row 0

86+Rollback

87+

88+We can also create a simple executable using `defaultMain`.

89+

90+>>> let main = defaultMain "host=localhost port=5432 dbname=exampledb" migrations

91+

92+>>> withArgs [] main

93+Invalid command: "". Use:

94+migrate to run all available migrations

95+rollback to rollback all available migrations

96+status to display migrations run and migrations left to run

97+

98+>>> withArgs ["status"] main

99+Migrations already run:

100+ None

101+Migrations left to run:

102+ - make users table

103+ - make emails table

104+

105+>>> withArgs ["migrate"] main

106+Migrations already run:

107+ - make users table

108+ - make emails table

109+Migrations left to run:

110+ None

111+

112+>>> withArgs ["rollback"] main

113+Migrations already run:

114+ None

115+Migrations left to run:

116+ - make users table

117+ - make emails table

118+

119+In addition to enabling `Migration`s using pure SQL `Definition`s for

120+the `up` and `down` instructions, you can also perform impure `IO` actions

121+by using a `Migration`s over the `Terminally` `PQ` `IO` category.

90-}

122-}

123

92{-# LANGUAGE

124{-# LANGUAGE

93 DataKinds

125 DataKinds

126+ , DeriveGeneric

127+ , FlexibleContexts

128+ , FlexibleInstances

94 , GADTs

129 , GADTs

95 , LambdaCase

130 , LambdaCase

96− , PolyKinds

97 , OverloadedLabels

131 , OverloadedLabels

132+ , OverloadedStrings

133+ , PolyKinds

134+ , QuantifiedConstraints

135+ , RankNTypes

98 , TypeApplications

136 , TypeApplications

99− , FlexibleContexts

100 , TypeOperators

137 , TypeOperators

101#-}

138#-}

102

139

103module Squeal.PostgreSQL.Migration

140module Squeal.PostgreSQL.Migration

104 ( -- * Migration

141 ( -- * Migration

105 Migration (..)

142 Migration (..)

106− , migrateUp

143+ , Migratory (..)

107− , migrateDown

144+ , Terminally (..)

108− -- * Aligned lists

145+ , terminally

109− , AlignedList (..)

146+ , pureMigration

110− , single

111− -- * Migration table

112 , MigrationsTable

147 , MigrationsTable

113− , createMigrations

148+ , defaultMain

114− , insertMigration

115− , deleteMigration

116− , selectMigration

117 ) where

149 ) where

118

150

119import Control.Category

151import Control.Category

120import Control.Monad

152import Control.Monad

121−import Control.Monad.Base

153+import Data.ByteString (ByteString)

122−import Control.Monad.Trans.Control

123−import Data.Monoid

154+import Data.Foldable (traverse_)

124−import Generics.SOP (K(..))

125import Data.Function ((&))

155import Data.Function ((&))

156+import Data.List ((\\))

126import Data.Text (Text)

157import Data.Text (Text)

158+import Data.Time (UTCTime)

127−import Prelude hiding (id, (.))

159+import Prelude hiding ((.), id)

160+import System.Environment

161+import UnliftIO (MonadIO (..))

162+

163+import qualified Data.Text.IO as Text (putStrLn)

164+import qualified Generics.SOP as SOP

165+import qualified GHC.Generics as GHC

128

166

129−import Squeal.PostgreSQL

167+import Squeal.PostgreSQL.Alias

168+import Squeal.PostgreSQL.Binary

169+import Squeal.PostgreSQL.Definition

170+import Squeal.PostgreSQL.Definition.Table

171+import Squeal.PostgreSQL.Definition.Table.Constraint

172+import Squeal.PostgreSQL.Expression.Comparison

173+import Squeal.PostgreSQL.Expression.Parameter

174+import Squeal.PostgreSQL.Expression.Time

175+import Squeal.PostgreSQL.Expression.Type

176+import Squeal.PostgreSQL.List

177+import Squeal.PostgreSQL.Manipulation

178+import Squeal.PostgreSQL.PQ

179+import Squeal.PostgreSQL.Query

180+import Squeal.PostgreSQL.Schema

181+import Squeal.PostgreSQL.Transaction

130

182

183+-- | A `Migration` is a named "isomorphism" over a given category.

131−-- | A `Migration` should contain an inverse pair of

184+-- It should contain an inverse pair of `up` and `down`

132−-- `up` and `down` instructions and a unique `name`.

185+-- instructions and a unique `name`.

133−data Migration io schema0 schema1 = Migration

186+data Migration p schemas0 schemas1 = Migration

134 { name :: Text -- ^ The `name` of a `Migration`.

187 { name :: Text -- ^ The `name` of a `Migration`.

135 -- Each `name` in a `Migration` should be unique.

188 -- Each `name` in a `Migration` should be unique.

136− , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.

189+ , up :: p schemas0 schemas1 -- ^ The `up` instruction of a `Migration`.

137− , down :: PQ schema1 schema0 io () -- ^ The `down` instruction of a `Migration`.

190+ , down :: p schemas1 schemas0 -- ^ The `down` instruction of a `Migration`.

191+ } deriving (GHC.Generic)

192+

193+{- |

194+A `Migratory` @p@ is a `Category` for which one can execute or rewind

195+a `Path` of `Migration`s over @p@. This includes the category of pure

196+SQL `Definition`s and the category of impure `Terminally` `PQ` `IO` actions.

197+-}

198+class Category p => Migratory p where

199+

200+ {- |

201+ Run a `Path` of `Migration`s.

202+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

203+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

204+ if not, `up` the `Migration` and insert its `name` in the `MigrationsTable`.

205+ -}

206+ migrateUp

207+ :: Path (Migration p) schemas0 schemas1

208+ -> PQ schemas0 schemas1 IO ()

209+

210+ {- |

211+ Rewind a `Path` of `Migration`s.

212+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

213+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

214+ if so, `down` the `Migration` and delete its `name` in the `MigrationsTable`.

215+ -}

216+ migrateDown

217+ :: Path (Migration p) schemas0 schemas1

218+ -> PQ schemas1 schemas0 IO ()

219+

220+instance Migratory Definition where

221+ migrateUp = migrateUp . cmap pureMigration

222+ migrateDown = migrateDown . cmap pureMigration

223+

224+{- | `Terminally` turns an indexed monad transformer and the monad it transforms

225+into a category by restricting the return type to @()@ and permuting the type variables.

226+This is similar to how applying a monad to @()@ yields a monoid.

227+Since a `Terminally` action has a trivial return value, the only reason

228+to run one is for the side effects, in particular database and other IO effects.

229+-}

230+newtype Terminally trans monad x0 x1 = Terminally

231+ { runTerminally :: trans x0 x1 monad () }

232+ deriving GHC.Generic

233+

234+instance

235+ ( IndexedMonadTransPQ trans

236+ , Monad monad

237+ , forall x0 x1. x0 ~ x1 => Monad (trans x0 x1 monad) )

238+ => Category (Terminally trans monad) where

239+ id = Terminally (return ())

240+ Terminally g . Terminally f = Terminally $ pqThen g f

241+

242+-- | `terminally` ignores the output of a computation, returning @()@ and

243+-- wrapping it up into a `Terminally`. You can lift an action in the base monad

244+-- by using @terminally . lift@.

245+terminally

246+ :: Functor (trans x0 x1 monad)

247+ => trans x0 x1 monad ignore

248+ -> Terminally trans monad x0 x1

249+terminally = Terminally . void

250+

251+-- | A `pureMigration` turns a `Migration` involving only pure SQL

252+-- `Definition`s into a `Migration` that may be combined with arbitrary `IO`.

253+pureMigration

254+ :: Migration Definition schemas0 schemas1

255+ -> Migration (Terminally PQ IO) schemas0 schemas1

256+pureMigration migration = Migration

257+ { name = name migration

258+ , up = terminally . define $ up migration

259+ , down = terminally . define $ down migration

138 }

260 }

139

261

140−-- | An `AlignedList` is a type-aligned list or free category.

262+instance Migratory (Terminally PQ IO) where

141−data AlignedList p x0 x1 where

142− Done :: AlignedList p x x

143− (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2

144−infixr 7 :>>

145−instance Category (AlignedList p) where

146− id = Done

147− (.) list = \case

148− Done -> list

149− step :>> steps -> step :>> (steps >>> list)

150−

151−-- | A `single` step.

152−single :: p x0 x1 -> AlignedList p x0 x1

153−single step = step :>> Done

154−

155−-- | Run `Migration`s by creating the `MigrationsTable`

156−-- if it does not exist and then in a transaction, for each each `Migration`

157−-- query to see if the `Migration` is executed. If not, then

158−-- execute the `Migration` and insert its row in the `MigrationsTable`.

159−migrateUp

160− :: MonadBaseControl IO io

161− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run

162− -> PQ

163− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

164− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

165− io ()

166−migrateUp migration =

167− define createMigrations

168− & pqBind okResult

169− & pqThen (transactionallySchema_ (upMigrations migration))

170− where

171

263

172− upMigrations

264+ migrateUp migration = unsafePQ . transactionally_ $ do

173− :: MonadBaseControl IO io

265+ define createMigrations

174− => AlignedList (Migration io) schema0 schema1

266+ upMigrations migration

175− -> PQ

267+

176− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

268+ where

177− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

269+

178− io ()

270+ upMigrations

271+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

272+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

179− upMigrations = \case

273+ upMigrations = \case

180− Done -> return ()

274+ Done -> return ()

181− step :>> steps -> upMigration step & pqThen (upMigrations steps)

275+ step :>> steps -> upMigration step >> upMigrations steps

182−

276+

183− upMigration

277+ upMigration

184− :: MonadBase IO io

278+ :: Migration (Terminally PQ IO) schemas0 schemas1

185− => Migration io schema0 schema1 -> PQ

279+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

186− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

187− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

188− io ()

189− upMigration step =

280+ upMigration step = do

190− queryExecuted step

281+ executed <- queryExecuted step

191− & pqBind (\ executed ->

282+ unless (executed == 1) $ do

192− if executed == 1 -- up step has already been executed

283+ unsafePQ . runTerminally $ up step

193− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

194− else

195− pqEmbed (up step) -- safely switch schemas

196− & pqThen (manipulateParams insertMigration (Only (name step)))

284+ manipulateParams_ insertMigration (Only (name step))

197− -- insert execution record

285+

198− & pqBind okResult)

199−

200− queryExecuted

286+ queryExecuted

201− :: MonadBase IO io

287+ :: Migration (Terminally PQ IO) schemas0 schemas1

202− => Migration io schema0 schema1 -> PQ

288+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

203− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

204− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

205− io Row

206− queryExecuted step = do

289+ queryExecuted step = do

207− result <- runQueryParams selectMigration (Only (name step))

290+ result <- runQueryParams selectMigration (Only (name step))

208− okResult result

209− ntuples result

291+ ntuples result

210−

292+

211−-- | Rewind `Migration`s by creating the `MigrationsTable`

293+ migrateDown migrations = unsafePQ . transactionally_ $ do

212−-- if it does not exist and then in a transaction, for each each `Migration`

294+ define createMigrations

213−-- query to see if the `Migration` is executed. If it is, then

295+ downMigrations migrations

214−-- rewind the `Migration` and delete its row in the `MigrationsTable`.

296+

215−migrateDown

297+ where

216− :: MonadBaseControl IO io

298+

217− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind

299+ downMigrations

218− -> PQ

300+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

219− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

301+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

220− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

302+ downMigrations = \case

221− io ()

303+ Done -> return ()

222−migrateDown migrations =

304+ step :>> steps -> downMigrations steps >> downMigration step

223− define createMigrations

224− & pqBind okResult

225− & pqThen (transactionallySchema_ (downMigrations migrations))

226− where

227

305

228− downMigrations

306+ downMigration

229− :: MonadBaseControl IO io

307+ :: Migration (Terminally PQ IO) schemas0 schemas1

230− => AlignedList (Migration io) schema0 schema1 -> PQ

308+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

231− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

232− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

233− io ()

234− downMigrations = \case

235− Done -> return ()

236− step :>> steps -> downMigrations steps & pqThen (downMigration step)

309+ downMigration step = do

237−

238− downMigration

239− :: MonadBase IO io

240− => Migration io schema0 schema1 -> PQ

241− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

242− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

243− io ()

244− downMigration step =

245− queryExecuted step

310+ executed <- queryExecuted step

246− & pqBind (\ executed ->

311+ unless (executed == 0) $ do

247− if executed == 0 -- up step has not been executed

312+ unsafePQ . runTerminally $ down step

248− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

249− else

250− pqEmbed (down step) -- safely switch schemas

251− & pqThen (manipulateParams deleteMigration (Only (name step)))

313+ manipulateParams_ deleteMigration (Only (name step))

252− -- delete execution record

314+

253− & pqBind okResult)

254−

255− queryExecuted

315+ queryExecuted

256− :: MonadBase IO io

316+ :: Migration (Terminally PQ IO) schemas0 schemas1

257− => Migration io schema0 schema1 -> PQ

317+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

258− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

259− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

260− io Row

261− queryExecuted step = do

318+ queryExecuted step = do

262− result <- runQueryParams selectMigration (Only (name step))

319+ result <- runQueryParams selectMigration (Only (name step))

263− okResult result

264− ntuples result

320+ ntuples result

265−

321+

266−okResult :: MonadBase IO io => K Result results -> PQ schema schema io ()

322+unsafePQ :: (Functor m) => PQ db0 db1 m x -> PQ db0' db1' m x

267−okResult result = do

323+unsafePQ (PQ pq) = PQ $ fmap (SOP.K . SOP.unK) . pq . SOP.K . SOP.unK

268− status <- resultStatus result

269− when (not (status `elem` [CommandOk, TuplesOk])) $ do

270− errorMessageMaybe <- resultErrorMessage result

271− case errorMessageMaybe of

272− Nothing -> error "migrateDown: unknown error"

273− Just msg -> error ("migrationDown: " <> show msg)

274

324

275-- | The `TableType` for a Squeal migration.

325-- | The `TableType` for a Squeal migration.

276type MigrationsTable =

326type MigrationsTable =

@@ -279,38 +329,120 @@ type MigrationsTable =

279 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

329 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

280 ]

330 ]

281

331

332+data MigrationRow =

333+ MigrationRow { migrationName :: Text

334+ , migrationTime :: UTCTime }

335+ deriving (GHC.Generic, Show)

336+

337+instance SOP.Generic MigrationRow

338+instance SOP.HasDatatypeInfo MigrationRow

339+

340+type MigrationsSchema = '["schema_migrations" ::: 'Table MigrationsTable]

341+type MigrationsSchemas = Public MigrationsSchema

342+

282-- | Creates a `MigrationsTable` if it does not already exist.

343-- | Creates a `MigrationsTable` if it does not already exist.

283−createMigrations

344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas

284− :: Has "schema_migrations" schema ('Table MigrationsTable)

285− => Definition schema schema

286createMigrations =

345createMigrations =

287 createTableIfNotExists #schema_migrations

346 createTableIfNotExists #schema_migrations

288− ( (text & notNullable) `As` #name :*

347+ ( (text & notNullable) `as` #name :*

289 (timestampWithTimeZone & notNullable & default_ currentTimestamp)

348 (timestampWithTimeZone & notNullable & default_ currentTimestamp)

290− `As` #executed_at :* Nil )

349+ `as` #executed_at )

291− ( unique (#name :* Nil) `As` #migrations_unique_name :* Nil )

350+ ( unique #name `as` #migrations_unique_name )

292−

351+

293−-- | Inserts a `Migration` into the `MigrationsTable`

352+-- | Inserts a `Migration` into the `MigrationsTable`, returning

294−insertMigration

353+-- the time at which it was inserted.

295− :: Has "schema_migrations" schema ('Table MigrationsTable)

354+insertMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

296− => Manipulation schema '[ 'NotNull 'PGtext] '[]

297−insertMigration = insertRow_ #schema_migrations

355+insertMigration = insertInto_ #schema_migrations

298− ( Set (param @1) `As` #name :*

299− Default `As` #executed_at :* Nil )

356+ (Values_ (Set (param @1) `as` #name :* Default `as` #executed_at))

300−

357+

301−-- | Deletes a `Migration` from the `MigrationsTable`

358+-- | Deletes a `Migration` from the `MigrationsTable`, returning

359+-- the time at which it was inserted.

302−deleteMigration

360+deleteMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

303− :: Has "schema_migrations" schema ('Table MigrationsTable)

304− => Manipulation schema '[ 'NotNull 'PGtext ] '[]

305deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

361deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

306

362

307-- | Selects a `Migration` from the `MigrationsTable`, returning

363-- | Selects a `Migration` from the `MigrationsTable`, returning

308−-- the time at which it was executed.

364+-- the time at which it was inserted.

309selectMigration

365selectMigration

310− :: Has "schema_migrations" schema ('Table MigrationsTable)

366+ :: Query_ MigrationsSchemas (Only Text) (Only UTCTime)

311− => Query schema '[ 'NotNull 'PGtext ]

312− '[ "executed_at" ::: 'NotNull 'PGtimestamptz ]

313−selectMigration = select

367+selectMigration = select_ (#executed_at `as` #fromOnly)

314− (#executed_at `As` #executed_at :* Nil)

315− ( from (table (#schema_migrations `As` #m))

368+ $ from (table (#schema_migrations))

316− & where_ (#name .== param @1))

369+ & where_ (#name .== param @1)

370+

371+selectMigrations :: Query_ MigrationsSchemas () MigrationRow

372+selectMigrations = select_

373+ (#name `as` #migrationName :* #executed_at `as` #migrationTime)

374+ (from (table #schema_migrations))

375+

376+data MigrateCommand

377+ = MigrateStatus

378+ | MigrateUp

379+ | MigrateDown deriving (GHC.Generic, Show)

380+

381+{- | `defaultMain` creates a simple executable

382+from a connection string and a list of `Migration`s. -}

383+defaultMain

384+ :: Migratory p

385+ => ByteString

386+ -- ^ connection string

387+ -> Path (Migration p) db0 db1

388+ -- ^ migrations

389+ -> IO ()

390+defaultMain connectTo migrations = do

391+ command <- readCommandFromArgs

392+ maybe (pure ()) performCommand command

393+

394+ where

395+

396+ performCommand :: MigrateCommand -> IO ()

397+ performCommand = \case

398+ MigrateStatus -> withConnection connectTo $

399+ suppressNotices >> migrateStatus

400+ MigrateUp -> withConnection connectTo $

401+ suppressNotices & pqThen (migrateUp migrations) & pqThen migrateStatus

402+ MigrateDown -> withConnection connectTo $

403+ suppressNotices & pqThen (migrateDown migrations) & pqThen migrateStatus

404+

405+ migrateStatus :: PQ schema schema IO ()

406+ migrateStatus = unsafePQ $ do

407+ runNames <- getRunMigrationNames

408+ let names = ctoList name migrations

409+ unrunNames = names \\ runNames

410+ liftIO $ displayRunned runNames >> displayUnrunned unrunNames

411+

412+ suppressNotices :: PQ schema schema IO ()

413+ suppressNotices = manipulate_ $

414+ UnsafeManipulation "SET client_min_messages TO WARNING;"

415+

416+ readCommandFromArgs :: IO (Maybe MigrateCommand)

417+ readCommandFromArgs = getArgs >>= \case

418+ ["migrate"] -> pure . Just $ MigrateUp

419+ ["rollback"] -> pure . Just $ MigrateDown

420+ ["status"] -> pure . Just $ MigrateStatus

421+ args -> displayUsage args >> pure Nothing

422+

423+ displayUsage :: [String] -> IO ()

424+ displayUsage args = do

425+ putStrLn $ "Invalid command: \"" <> unwords args <> "\". Use:"

426+ putStrLn "migrate to run all available migrations"

427+ putStrLn "rollback to rollback all available migrations"

428+ putStrLn "status to display migrations run and migrations left to run"

429+

430+ getRunMigrationNames :: (MonadIO m) => PQ db0 db0 m [Text]

431+ getRunMigrationNames =

432+ fmap migrationName <$> (unsafePQ (define createMigrations & pqThen (runQuery selectMigrations)) >>= getRows)

433+

434+ displayListOfNames :: [Text] -> IO ()

435+ displayListOfNames [] = Text.putStrLn " None"

436+ displayListOfNames xs =

437+ let singleName n = Text.putStrLn $ " - " <> n

438+ in traverse_ singleName xs

439+

440+ displayUnrunned :: [Text] -> IO ()

441+ displayUnrunned unrunned =

442+ Text.putStrLn "Migrations left to run:"

443+ >> displayListOfNames unrunned

444+

445+ displayRunned :: [Text] -> IO ()

446+ displayRunned runned =

447+ Text.putStrLn "Migrations already run:"

448+ >> displayListOfNames runned

squeal-postgresql/src/Squeal/PostgreSQL/PG.hsnew file+388

@@ -0,0 +1,388 @@

1+{-|

2+Module: Squeal.PostgreSQL.PG

3+Description: Embedding of Haskell types into Postgres's type system

4+Copyright: (c) Eitan Chatav, 2010

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+`Squeal.PostgreSQL.PG` provides type families for turning Haskell

9+`Type`s into corresponding Postgres types.

10+-}

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DeriveAnyClass

14+ , DeriveFoldable

15+ , DeriveFunctor

16+ , DeriveGeneric

17+ , DeriveTraversable

18+ , DerivingStrategies

19+ , DefaultSignatures

20+ , FlexibleContexts

21+ , FlexibleInstances

22+ , FunctionalDependencies

23+ , GADTs

24+ , LambdaCase

25+ , MultiParamTypeClasses

26+ , OverloadedStrings

27+ , ScopedTypeVariables

28+ , TypeApplications

29+ , TypeFamilies

30+ , TypeInType

31+ , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

34+#-}

35+

36+module Squeal.PostgreSQL.PG

37+ ( -- * PG embeddings

38+ PG

39+ , NullPG

40+ , TuplePG

41+ , RowPG

42+ -- * Storage newtypes

43+ , Money (..)

44+ , Json (..)

45+ , Jsonb (..)

46+ , Composite (..)

47+ , Enumerated (..)

48+ , VarArray (..)

49+ , FixArray (..)

50+ , LibPQ.Oid (..)

51+ -- * Type families

52+ , LabelsPG

53+ , DimPG

54+ , FixPG

55+ , TupleOf

56+ , TupleCodeOf

57+ , RowOf

58+ , ConstructorsOf

59+ , ConstructorNameOf

60+ , ConstructorNamesOf

61+ ) where

62+

63+import Data.Aeson (Value)

64+import Data.Kind (Type)

65+import Data.Int (Int16, Int32, Int64)

66+import Data.Scientific (Scientific)

67+import Data.Time (Day, DiffTime, LocalTime, TimeOfDay, TimeZone, UTCTime)

68+import Data.Vector (Vector)

69+import Data.UUID.Types (UUID)

70+import GHC.TypeLits

71+import Network.IP.Addr (NetAddr, IP)

72+

73+import qualified Data.ByteString.Lazy as Lazy (ByteString)

74+import qualified Data.ByteString as Strict (ByteString)

75+import qualified Data.Text.Lazy as Lazy (Text)

76+import qualified Data.Text as Strict (Text)

77+import qualified Database.PostgreSQL.LibPQ as LibPQ

78+import qualified GHC.Generics as GHC

79+import qualified Generics.SOP as SOP

80+import qualified Generics.SOP.Record as SOP

81+import qualified Generics.SOP.Type.Metadata as Type

82+

83+import Squeal.PostgreSQL.Alias

84+import Squeal.PostgreSQL.Schema

85+

86+-- $setup

87+-- >>> import Squeal.PostgreSQL

88+-- >>> import Data.Text (Text)

89+

90+{- | The `PG` type family embeds a subset of Haskell types

91+as Postgres types. As an open type family, `PG` is extensible.

92+

93+>>> :kind! PG LocalTime

94+PG LocalTime :: PGType

95+= 'PGtimestamp

96+

97+>>> newtype MyDouble = My Double

98+>>> :set -XTypeFamilies

99+>>> type instance PG MyDouble = 'PGfloat8

100+-}

101+type family PG (hask :: Type) :: PGType

102+-- | `PGbool`

103+type instance PG Bool = 'PGbool

104+-- | `PGint2`

105+type instance PG Int16 = 'PGint2

106+-- | `PGint4`

107+type instance PG Int32 = 'PGint4

108+-- | `PGint8`

109+type instance PG Int64 = 'PGint8

110+-- | `PGint2`

111+type instance PG LibPQ.Oid = 'PGoid

112+-- | `PGnumeric`

113+type instance PG Scientific = 'PGnumeric

114+-- | `PGfloat4`

115+type instance PG Float = 'PGfloat4

116+-- | `PGfloat8`

117+type instance PG Double = 'PGfloat8

118+-- | `PGchar` @1@

119+type instance PG Char = 'PGchar 1

120+-- | `PGtext`

121+type instance PG Strict.Text = 'PGtext

122+-- | `PGtext`

123+type instance PG Lazy.Text = 'PGtext

124+-- | `PGtext`

125+type instance PG String = 'PGtext

126+-- | `PGbytea`

127+type instance PG Strict.ByteString = 'PGbytea

128+-- | `PGbytea`

129+type instance PG Lazy.ByteString = 'PGbytea

130+-- | `PGtimestamp`

131+type instance PG LocalTime = 'PGtimestamp

132+-- | `PGtimestamptz`

133+type instance PG UTCTime = 'PGtimestamptz

134+-- | `PGdate`

135+type instance PG Day = 'PGdate

136+-- | `PGtime`

137+type instance PG TimeOfDay = 'PGtime

138+-- | `PGtimetz`

139+type instance PG (TimeOfDay, TimeZone) = 'PGtimetz

140+-- | `PGinterval`

141+type instance PG DiffTime = 'PGinterval

142+-- | `PGuuid`

143+type instance PG UUID = 'PGuuid

144+-- | `PGinet`

145+type instance PG (NetAddr IP) = 'PGinet

146+-- | `PGjson`

147+type instance PG Value = 'PGjson

148+

149+{-| The `LabelsPG` type family calculates the constructors of a

150+Haskell enum type.

151+

152+>>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

153+>>> instance SOP.Generic Schwarma

154+>>> instance SOP.HasDatatypeInfo Schwarma

155+>>> :kind! LabelsPG Schwarma

156+LabelsPG Schwarma :: [Type.ConstructorName]

157+= '["Beef", "Lamb", "Chicken"]

158+-}

159+type family LabelsPG (hask :: Type) :: [Type.ConstructorName] where

160+ LabelsPG hask =

161+ ConstructorNamesOf (ConstructorsOf (SOP.DatatypeInfoOf hask))

162+

163+{- |

164+`RowPG` turns a Haskell `Type` into a `RowType`.

165+

166+`RowPG` may be applied to normal Haskell record types provided they

167+have `SOP.Generic` and `SOP.HasDatatypeInfo` instances;

168+

169+>>> data Person = Person { name :: Strict.Text, age :: Int32 } deriving GHC.Generic

170+>>> instance SOP.Generic Person

171+>>> instance SOP.HasDatatypeInfo Person

172+>>> :kind! RowPG Person

173+RowPG Person :: [(Symbol, NullityType)]

174+= '["name" ::: 'NotNull 'PGtext, "age" ::: 'NotNull 'PGint4]

175+-}

176+type family RowPG (hask :: Type) :: RowType where

177+ RowPG hask = RowOf (SOP.RecordCodeOf hask)

178+

179+-- | `RowOf` applies `NullPG` to the fields of a list.

180+type family RowOf (record :: [(Symbol, Type)]) :: RowType where

181+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': col4 ::: ty4 ': record) =

182+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': col4 ::: NullPG ty4 ': RowOf record

183+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': record) =

184+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': RowOf record

185+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': record) =

186+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': RowOf record

187+ RowOf (col ::: ty ': col1 ::: ty1 ': record) =

188+ col ::: NullPG ty ': col1::: NullPG ty1 ': RowOf record

189+ RowOf (col ::: ty ': record) = col ::: NullPG ty ': RowOf record

190+ RowOf '[] = '[]

191+

192+{- | `NullPG` turns a Haskell type into a `NullityType`.

193+

194+>>> :kind! NullPG Double

195+NullPG Double :: NullityType

196+= 'NotNull 'PGfloat8

197+>>> :kind! NullPG (Maybe Double)

198+NullPG (Maybe Double) :: NullityType

199+= 'Null 'PGfloat8

200+-}

201+type family NullPG (hask :: Type) :: NullityType where

202+ NullPG (Maybe hask) = 'Null (PG hask)

203+ NullPG hask = 'NotNull (PG hask)

204+

205+{- | `TuplePG` turns a Haskell tuple type (including record types) into

206+the corresponding list of `NullityType`s.

207+

208+>>> :kind! TuplePG (Double, Maybe Char)

209+TuplePG (Double, Maybe Char) :: [NullityType]

210+= '[ 'NotNull 'PGfloat8, 'Null ('PGchar 1)]

211+-}

212+type family TuplePG (hask :: Type) :: [NullityType] where

213+ TuplePG hask = TupleOf (TupleCodeOf hask (SOP.Code hask))

214+

215+-- | `TupleOf` turns a list of Haskell `Type`s into a list of `NullityType`s.

216+type family TupleOf (tuple :: [Type]) :: [NullityType] where

217+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': hask5 ': tuple) =

218+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': NullPG hask5 ': TupleOf tuple

219+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': tuple) =

220+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': TupleOf tuple

221+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': tuple) =

222+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': TupleOf tuple

223+ TupleOf (hask ': hask1 ': hask2 ': tuple) =

224+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': TupleOf tuple

225+ TupleOf (hask ': hask1 ': tuple) = NullPG hask ': NullPG hask1 ': TupleOf tuple

226+ TupleOf (hask ': tuple) = NullPG hask ': TupleOf tuple

227+ TupleOf '[] = '[]

228+

229+-- | `TupleCodeOf` takes the `SOP.Code` of a haskell `Type`

230+-- and if it's a simple product returns it, otherwise giving a `TypeError`.

231+type family TupleCodeOf (hask :: Type) (code :: [[Type]]) :: [Type] where

232+ TupleCodeOf hask '[tuple] = tuple

233+ TupleCodeOf hask '[] =

234+ TypeError

235+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

236+ ':$$: 'Text "It is a void type with no constructors."

237+ )

238+ TupleCodeOf hask (_ ': _ ': _) =

239+ TypeError

240+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

241+ ':$$: 'Text "It is a sum type with more than one constructor."

242+ )

243+

244+-- | Calculates constructors of a datatype.

245+type family ConstructorsOf (datatype :: Type.DatatypeInfo)

246+ :: [Type.ConstructorInfo] where

247+ ConstructorsOf ('Type.ADT _module _datatype constructors) =

248+ constructors

249+ ConstructorsOf ('Type.Newtype _module _datatype constructor) =

250+ '[constructor]

251+

252+-- | Calculates the name of a nullary constructor, otherwise

253+-- generates a type error.

254+type family ConstructorNameOf (constructor :: Type.ConstructorInfo)

255+ :: Type.ConstructorName where

256+ ConstructorNameOf ('Type.Constructor name) = name

257+ ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

258+ ('Text "ConstructorNameOf error: non-nullary constructor "

259+ ':<>: 'Text name)

260+ ConstructorNameOf ('Type.Record name _fields) = TypeError

261+ ('Text "ConstructorNameOf error: non-nullary constructor "

262+ ':<>: 'Text name)

263+

264+-- | Calculate the names of nullary constructors.

265+type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

266+ :: [Type.ConstructorName] where

267+ ConstructorNamesOf '[] = '[]

268+ ConstructorNamesOf (constructor ': constructors) =

269+ ConstructorNameOf constructor ': ConstructorNamesOf constructors

270+

271+-- | `DimPG` turns Haskell nested homogeneous tuples into a list of lengths.

272+type family DimPG (hask :: Type) :: [Nat] where

273+ DimPG (x,x) = 2 ': DimPG x

274+ DimPG (x,x,x) = 3 ': DimPG x

275+ DimPG (x,x,x,x) = 4 ': DimPG x

276+ DimPG (x,x,x,x,x) = 5 ': DimPG x

277+ DimPG (x,x,x,x,x,x) = 6 ': DimPG x

278+ DimPG (x,x,x,x,x,x,x) = 7 ': DimPG x

279+ DimPG (x,x,x,x,x,x,x,x) = 8 ': DimPG x

280+ DimPG (x,x,x,x,x,x,x,x,x) = 9 ': DimPG x

281+ DimPG (x,x,x,x,x,x,x,x,x,x) = 10 ': DimPG x

282+ DimPG x = '[]

283+

284+-- | `FixPG` extracts `NullPG` of the base type of nested homogeneous tuples.

285+type family FixPG (hask :: Type) :: NullityType where

286+ FixPG (x,x) = FixPG x

287+ FixPG (x,x,x) = FixPG x

288+ FixPG (x,x,x,x) = FixPG x

289+ FixPG (x,x,x,x,x) = FixPG x

290+ FixPG (x,x,x,x,x,x) = FixPG x

291+ FixPG (x,x,x,x,x,x,x) = FixPG x

292+ FixPG (x,x,x,x,x,x,x,x) = FixPG x

293+ FixPG (x,x,x,x,x,x,x,x,x) = FixPG x

294+ FixPG (x,x,x,x,x,x,x,x,x,x) = FixPG x

295+ FixPG (x,x,x,x,x,x,x,x,x,x,x) = FixPG x

296+ FixPG x = NullPG x

297+

298+{- | The `Money` newtype stores a monetary value in terms

299+of the number of cents, i.e. @$2,000.20@ would be expressed as

300+@Money { cents = 200020 }@.

301+

302+>>> import Control.Monad (void)

303+>>> import Control.Monad.IO.Class (liftIO)

304+>>> import Squeal.PostgreSQL

305+>>> :{

306+let

307+ roundTrip :: Query_ (Public '[]) (Only Money) (Only Money)

308+ roundTrip = values_ $ parameter @1 money `as` #fromOnly

309+:}

310+

311+>>> let input = Only (Money 20020)

312+

313+>>> :{

314+withConnection "host=localhost port=5432 dbname=exampledb" $ do

315+ result <- runQueryParams roundTrip input

316+ Just output <- firstRow result

317+ liftIO . print $ input == output

318+:}

319+True

320+-}

321+newtype Money = Money { cents :: Int64 }

322+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

323+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

324+-- | `PGmoney`

325+type instance PG Money = 'PGmoney

326+

327+{- | The `Json` newtype is an indication that the Haskell

328+type it's applied to should be stored as a `PGjson`.

329+-}

330+newtype Json hask = Json {getJson :: hask}

331+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

332+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

333+-- | `PGjson`

334+type instance PG (Json hask) = 'PGjson

335+

336+{- | The `Jsonb` newtype is an indication that the Haskell

337+type it's applied to should be stored as a `PGjsonb`.

338+-}

339+newtype Jsonb hask = Jsonb {getJsonb :: hask}

340+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

341+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

342+-- | `PGjsonb`

343+type instance PG (Jsonb hask) = 'PGjsonb

344+

345+{- | The `Composite` newtype is an indication that the Haskell

346+type it's applied to should be stored as a `PGcomposite`.

347+-}

348+newtype Composite record = Composite {getComposite :: record}

349+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

350+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

351+-- | `PGcomposite` @(@`RowPG` @hask)@

352+type instance PG (Composite hask) = 'PGcomposite (RowPG hask)

353+

354+{- | The `Enumerated` newtype is an indication that the Haskell

355+type it's applied to should be stored as a `PGenum`.

356+-}

357+newtype Enumerated enum = Enumerated {getEnumerated :: enum}

358+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

359+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

360+-- | `PGenum` @(@`LabelsPG` @hask)@

361+type instance PG (Enumerated hask) = 'PGenum (LabelsPG hask)

362+

363+{- | The `VarArray` newtype is an indication that the Haskell

364+type it's applied to should be stored as a `PGvararray`.

365+

366+>>> :kind! PG (VarArray (Vector Double))

367+PG (VarArray (Vector Double)) :: PGType

368+= 'PGvararray ('NotNull 'PGfloat8)

369+-}

370+newtype VarArray arr = VarArray {getVarArray :: arr}

371+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

372+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

373+-- | `PGvararray` @(@`NullPG` @hask)@

374+type instance PG (VarArray (Vector hask)) = 'PGvararray (NullPG hask)

375+type instance PG (VarArray [hask]) = 'PGvararray (NullPG hask)

376+

377+{- | The `FixArray` newtype is an indication that the Haskell

378+type it's applied to should be stored as a `PGfixarray`.

379+

380+>>> :kind! PG (FixArray ((Double, Double), (Double, Double)))

381+PG (FixArray ((Double, Double), (Double, Double))) :: PGType

382+= 'PGfixarray '[2, 2] ('NotNull 'PGfloat8)

383+-}

384+newtype FixArray arr = FixArray {getFixArray :: arr}

385+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

386+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

387+-- | `PGfixarray` @(@`DimPG` @hask) (@`FixPG` @hask)@

388+type instance PG (FixArray hask) = 'PGfixarray (DimPG hask) (FixPG hask)

squeal-postgresql/src/Squeal/PostgreSQL/PQ.hs+312−211

@@ -6,12 +6,12 @@ Maintainer: eitan@morphism.tech

6Stability: experimental

8This module is where Squeal commands actually get executed by

9−`LibPQ`. It containts two typeclasses, `IndexedMonadTransPQ` for executing

9+`Database.PostgreSQL.LibPQ`. It containts two typeclasses, `IndexedMonadTransPQ` for executing

10a `Definition` and `MonadPQ` for executing a `Manipulation` or `Query`,

11and a `PQ` type with instances for them.

13Using Squeal in your application will come down to defining

14−the @schema@ of your database and including @PQ schema schema@ in your

14+the @schemas@ of your database and including @PQ schemas schemas@ in your

15application's monad transformer stack, giving it an instance of `MonadPQ`.

17This module also provides functions for retrieving rows from the `LibPQ.Result`

@@ -24,6 +24,7 @@ of executing Squeal commands.

24 , FunctionalDependencies

25 , FlexibleContexts

26 , FlexibleInstances

27+ , InstanceSigs

27 , OverloadedStrings

28 , OverloadedStrings

28 , RankNTypes

29 , RankNTypes

29 , ScopedTypeVariables

30 , ScopedTypeVariables

@@ -48,9 +49,7 @@ module Squeal.PostgreSQL.PQ

48 , evalPQ

49 , evalPQ

49 , IndexedMonadTransPQ (..)

50 , IndexedMonadTransPQ (..)

50 , MonadPQ (..)

51 , MonadPQ (..)

51− , PQRun

52+ -- * Results

52− , pqliftWith

53− -- * Result

54 , LibPQ.Result

53 , LibPQ.Result

55 , LibPQ.Row

54 , LibPQ.Row

56 , ntuples

55 , ntuples

@@ -62,22 +61,33 @@ module Squeal.PostgreSQL.PQ

62 , LibPQ.ExecStatus (..)

61 , LibPQ.ExecStatus (..)

63 , resultStatus

62 , resultStatus

64 , resultErrorMessage

63 , resultErrorMessage

64+ , resultErrorCode

65+ -- * Exceptions

66+ , SquealException (..)

67+ , PQState (..)

68+ , okResult

69+ , catchSqueal

70+ , handleSqueal

71+ , trySqueal

65 ) where

72 ) where

67−import Control.Exception.Lifted

74+import Control.Exception (Exception, throw)

68−import Control.Monad.Base

69import Control.Monad.Except

75import Control.Monad.Except

70import Control.Monad.Morph

76import Control.Monad.Morph

71−import Control.Monad.Trans.Control

77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)

72import Data.ByteString (ByteString)

78import Data.ByteString (ByteString)

73import Data.Foldable

79import Data.Foldable

74import Data.Function ((&))

80import Data.Function ((&))

81+import Data.Functor ((<&>))

75import Data.Kind

82import Data.Kind

76−import Data.Monoid

83+import Data.Text (pack, Text)

77import Data.Traversable

84import Data.Traversable

78import Generics.SOP

85import Generics.SOP

86+import PostgreSQL.Binary.Encoding (encodingBytes)

88+import qualified Control.Monad.Fail as Fail

80import qualified Database.PostgreSQL.LibPQ as LibPQ

89import qualified Database.PostgreSQL.LibPQ as LibPQ

90+import qualified PostgreSQL.Binary.Encoding as Encoding

82import Squeal.PostgreSQL.Binary

92import Squeal.PostgreSQL.Binary

83import Squeal.PostgreSQL.Definition

93import Squeal.PostgreSQL.Definition

@@ -90,7 +100,6 @@ import Control.Monad.Trans.Identity

90import Control.Monad.Trans.Reader

100import Control.Monad.Trans.Reader

91import Control.Monad.Trans.Maybe

101import Control.Monad.Trans.Maybe

92import Control.Monad.Trans.Cont

102import Control.Monad.Trans.Cont

93−import Control.Monad.Trans.List

103

95import qualified Control.Monad.Trans.State.Lazy as Lazy

104import qualified Control.Monad.Trans.State.Lazy as Lazy

96import qualified Control.Monad.Trans.State.Strict as Strict

105import qualified Control.Monad.Trans.State.Strict as Strict

@@ -99,6 +108,9 @@ import qualified Control.Monad.Trans.Writer.Strict as Strict

99import qualified Control.Monad.Trans.RWS.Lazy as Lazy

108import qualified Control.Monad.Trans.RWS.Lazy as Lazy

100import qualified Control.Monad.Trans.RWS.Strict as Strict

109import qualified Control.Monad.Trans.RWS.Strict as Strict

101

110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

102{- | Makes a new connection to the database server.

114{- | Makes a new connection to the database server.

103

115

104This function opens a new database connection using the parameters taken

116This function opens a new database connection using the parameters taken

@@ -125,22 +137,22 @@ Note that, for now, squeal doesn't offer any protection from connecting

125with the wrong schema!

137with the wrong schema!

126-}

138-}

127connectdb

139connectdb

128− :: forall schema io

140+ :: forall schemas io

129− . MonadBase IO io

141+ . MonadIO io

130 => ByteString -- ^ conninfo

142 => ByteString -- ^ conninfo

131− -> io (K LibPQ.Connection schema)

143+ -> io (K LibPQ.Connection schemas)

132−connectdb = fmap K . liftBase . LibPQ.connectdb

144+connectdb = fmap K . liftIO . LibPQ.connectdb

133

145

134-- | Closes the connection to the server.

146-- | Closes the connection to the server.

135−finish :: MonadBase IO io => K LibPQ.Connection schema -> io ()

147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()

136−finish = liftBase . LibPQ.finish . unK

148+finish = liftIO . LibPQ.finish . unK

137

149

138-- | Do `connectdb` and `finish` before and after a computation.

150-- | Do `connectdb` and `finish` before and after a computation.

139withConnection

151withConnection

140− :: forall schema0 schema1 io x

152+ :: forall schemas0 schemas1 io x

141− . MonadBaseControl IO io

153+ . MonadUnliftIO io

142 => ByteString

154 => ByteString

143− -> PQ schema0 schema1 io x

155+ -> PQ schemas0 schemas1 io x

144 -> io x

156 -> io x

145withConnection connString action = do

157withConnection connString action = do

146 K x <- bracket (connectdb connString) finish (unPQ action)

158 K x <- bracket (connectdb connString) finish (unPQ action)

@@ -148,47 +160,47 @@ withConnection connString action = do

148

160

149-- | Safely `lowerConnection` to a smaller schema.

161-- | Safely `lowerConnection` to a smaller schema.

150lowerConnection

162lowerConnection

151− :: K LibPQ.Connection (table ': schema)

163+ :: K LibPQ.Connection (schema ': schemas)

152− -> K LibPQ.Connection schema

164+ -> K LibPQ.Connection schemas

153lowerConnection (K conn) = K conn

165lowerConnection (K conn) = K conn

154

166

155-- | We keep track of the schema via an Atkey indexed state monad transformer,

167-- | We keep track of the schema via an Atkey indexed state monad transformer,

156-- `PQ`.

168-- `PQ`.

157newtype PQ

169newtype PQ

158− (schema0 :: SchemaType)

170+ (schemas0 :: SchemasType)

159− (schema1 :: SchemaType)

171+ (schemas1 :: SchemasType)

160 (m :: Type -> Type)

172 (m :: Type -> Type)

161 (x :: Type) =

173 (x :: Type) =

162− PQ { unPQ :: K LibPQ.Connection schema0 -> m (K x schema1) }

174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }

163

175

164−instance Monad m => Functor (PQ schema0 schema1 m) where

176+instance Monad m => Functor (PQ schemas0 schemas1 m) where

165 fmap f (PQ pq) = PQ $ \ conn -> do

177 fmap f (PQ pq) = PQ $ \ conn -> do

166 K x <- pq conn

178 K x <- pq conn

167 return $ K (f x)

179 return $ K (f x)

168

180

169−-- | Run a `PQ` and keep the result and the `Connection`.

181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.

170runPQ

182runPQ

171 :: Functor m

183 :: Functor m

172− => PQ schema0 schema1 m x

184+ => PQ schemas0 schemas1 m x

173− -> K LibPQ.Connection schema0

185+ -> K LibPQ.Connection schemas0

174− -> m (x, K LibPQ.Connection schema1)

186+ -> m (x, K LibPQ.Connection schemas1)

175runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

187runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

176 -- K x <- pq conn

188 -- K x <- pq conn

177 -- return (x, K (unK conn))

189 -- return (x, K (unK conn))

178

190

179−-- | Execute a `PQ` and discard the result but keep the `Connection`.

191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.

180execPQ

192execPQ

181 :: Functor m

193 :: Functor m

182− => PQ schema0 schema1 m x

194+ => PQ schemas0 schemas1 m x

183− -> K LibPQ.Connection schema0

195+ -> K LibPQ.Connection schemas0

184− -> m (K LibPQ.Connection schema1)

196+ -> m (K LibPQ.Connection schemas1)

185execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

197execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

186

198

187−-- | Evaluate a `PQ` and discard the `Connection` but keep the result.

199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.

188evalPQ

200evalPQ

189 :: Functor m

201 :: Functor m

190− => PQ schema0 schema1 m x

202+ => PQ schemas0 schemas1 m x

191− -> K LibPQ.Connection schema0

203+ -> K LibPQ.Connection schemas0

192 -> m x

204 -> m x

193evalPQ (PQ pq) conn = unK <$> pq conn

205evalPQ (PQ pq) conn = unK <$> pq conn

194

206

@@ -196,60 +208,56 @@ evalPQ (PQ pq) conn = unK <$> pq conn

196-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

208-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

197-- An indexed monad transformer transforms a `Monad` into an indexed monad.

209-- An indexed monad transformer transforms a `Monad` into an indexed monad.

198-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

210-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

199−-- support running `Definition`s using `define` and embedding a computation

211+-- support running `Definition`s using `define`.

200−-- in a larger schema using `pqEmbed`.

201class IndexedMonadTransPQ pq where

212class IndexedMonadTransPQ pq where

202

213

203 -- | indexed analog of `<*>`

214 -- | indexed analog of `<*>`

204 pqAp

215 pqAp

205 :: Monad m

216 :: Monad m

206− => pq schema0 schema1 m (x -> y)

217+ => pq schemas0 schemas1 m (x -> y)

207− -> pq schema1 schema2 m x

218+ -> pq schemas1 schemas2 m x

208− -> pq schema0 schema2 m y

219+ -> pq schemas0 schemas2 m y

209

220

210 -- | indexed analog of `join`

221 -- | indexed analog of `join`

211 pqJoin

222 pqJoin

212 :: Monad m

223 :: Monad m

213− => pq schema0 schema1 m (pq schema1 schema2 m y)

224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)

214− -> pq schema0 schema2 m y

225+ -> pq schemas0 schemas2 m y

215 pqJoin pq = pq & pqBind id

226 pqJoin pq = pq & pqBind id

216

227

217 -- | indexed analog of `=<<`

228 -- | indexed analog of `=<<`

218 pqBind

229 pqBind

219 :: Monad m

230 :: Monad m

220− => (x -> pq schema1 schema2 m y)

231+ => (x -> pq schemas1 schemas2 m y)

221− -> pq schema0 schema1 m x

232+ -> pq schemas0 schemas1 m x

222− -> pq schema0 schema2 m y

233+ -> pq schemas0 schemas2 m y

223

234

224 -- | indexed analog of flipped `>>`

235 -- | indexed analog of flipped `>>`

225 pqThen

236 pqThen

226 :: Monad m

237 :: Monad m

227− => pq schema1 schema2 m y

238+ => pq schemas1 schemas2 m y

228− -> pq schema0 schema1 m x

239+ -> pq schemas0 schemas1 m x

229− -> pq schema0 schema2 m y

240+ -> pq schemas0 schemas2 m y

230 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

241 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

231

242

232 -- | indexed analog of `<=<`

243 -- | indexed analog of `<=<`

233 pqAndThen

244 pqAndThen

234 :: Monad m

245 :: Monad m

235− => (y -> pq schema1 schema2 m z)

246+ => (y -> pq schemas1 schemas2 m z)

236− -> (x -> pq schema0 schema1 m y)

247+ -> (x -> pq schemas0 schemas1 m y)

237− -> x -> pq schema0 schema2 m z

248+ -> x -> pq schemas0 schemas2 m z

238 pqAndThen g f x = pqBind g (f x)

249 pqAndThen g f x = pqBind g (f x)

239

250

240− -- | Safely embed a computation in a larger schema.

241− pqEmbed

242− :: Monad m

243− => pq schema0 schema1 m x

244− -> pq (table ': schema0) (table : schema1) m x

245−

246− -- | Run a `Definition` with `LibPQ.exec`, we expect that libpq obeys the law

251+ -- | Run a `Definition` with `LibPQ.exec`.

252+ --

253+ -- It should be functorial in effect.

247 --

254 --

255+ -- @define id = return ()@

248− -- @define statement1 & pqThen (define statement2) = define (statement1 >>> statement2)@

256+ -- @define (statement1 >>> statement2) = define statement1 & pqThen (define statement2)@

249 define

257 define

250− :: MonadBase IO io

258+ :: MonadIO io

251− => Definition schema0 schema1

259+ => Definition schemas0 schemas1

252− -> pq schema0 schema1 io (K LibPQ.Result '[])

260+ -> pq schemas0 schemas1 io ()

253

261

254instance IndexedMonadTransPQ PQ where

262instance IndexedMonadTransPQ PQ where

255

263

@@ -262,26 +270,26 @@ instance IndexedMonadTransPQ PQ where

262 K x' <- x conn

270 K x' <- x conn

263 unPQ (f x') (K (unK conn))

271 unPQ (f x') (K (unK conn))

264

272

265− pqEmbed (PQ pq) = PQ $ \ (K conn) -> do

266− K x <- pq (K conn)

267− return $ K x

268−

269 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

273 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

270− resultMaybe <- liftBase $ LibPQ.exec conn q

274+ resultMaybe <- liftIO $ LibPQ.exec conn q

271 case resultMaybe of

275 case resultMaybe of

272− Nothing -> error

276+ Nothing -> throw $ ResultException

273 "define: LibPQ.exec returned no results"

277 "define: LibPQ.exec returned no results"

274− Just result -> return $ K (K result)

278+ Just result -> K <$> okResult_ result

275

279

276−{- | `MonadPQ` is an `mtl` style constraint, similar to

280+{- | `MonadPQ` is an @mtl@ style constraint, similar to

277−`Control.Monad.State.Class.MonadState`, for using `LibPQ` to

281+`Control.Monad.State.Class.MonadState`, for using `Database.PostgreSQL.LibPQ` to

278

282

279* `manipulateParams` runs a `Manipulation` with params from a type

283* `manipulateParams` runs a `Manipulation` with params from a type

280 with a `ToParams` constraint. It calls `LibPQ.execParams` and

284 with a `ToParams` constraint. It calls `LibPQ.execParams` and

281 doesn't afraid of anything.

285 doesn't afraid of anything.

282

286

287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.

288+

283* `manipulate` is like `manipulateParams` for a parameter-free statement.

289* `manipulate` is like `manipulateParams` for a parameter-free statement.

284

290

291+* `manipulate_` is like `manipulate` for a returning-free statement.

292+

285* `runQueryParams` is like `manipulateParams` for query statements.

293* `runQueryParams` is like `manipulateParams` for query statements.

286

294

287* `runQuery` is like `runQueryParams` for a parameter-free statement.

295* `runQuery` is like `runQueryParams` for a parameter-free statement.

@@ -295,11 +303,11 @@ instance IndexedMonadTransPQ PQ where

295* `forPrepared` is a flipped `traversePrepared`

303* `forPrepared` is a flipped `traversePrepared`

296

304

297* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

305* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

298− containers and returns unit.

306+ containers for a returning-free statement.

299

307

300* `forPrepared_` is a flipped `traversePrepared_`.

308* `forPrepared_` is a flipped `traversePrepared_`.

301

309

302−* `liftPQ` lets you lift actions from `LibPQ` that require a connection

310+* `liftPQ` lets you lift actions from `Database.PostgreSQL.LibPQ` that require a connection

303 into your monad.

311 into your monad.

304

312

305To define an instance, you can minimally define only `manipulateParams`,

313To define an instance, you can minimally define only `manipulateParams`,

@@ -307,305 +315,398 @@ To define an instance, you can minimally define only `manipulateParams`,

307a default instance.

315a default instance.

308

316

309-}

317-}

310−class Monad pq => MonadPQ schema pq | pq -> schema where

318+class Monad pq => MonadPQ schemas pq | pq -> schemas where

311 manipulateParams

319 manipulateParams

312− :: ToParams x params

320+ :: (ToParams x params, All OidOfParam params)

313− => Manipulation schema params ys

321+ => Manipulation '[] schemas params ys

314− -- ^ `insertRows`, `update` or `deleteFrom`

322+ -- ^ `insertInto`, `update` or `deleteFrom`

315 -> x -> pq (K LibPQ.Result ys)

323 -> x -> pq (K LibPQ.Result ys)

316 default manipulateParams

324 default manipulateParams

317− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

325+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

318− => ToParams x params

326+ => (ToParams x params, All OidOfParam params)

319− => Manipulation schema params ys

327+ => Manipulation '[] schemas params ys

320− -- ^ `insertRows`, `update` or `deleteFrom`

328+ -- ^ `insertInto`, `update` or `deleteFrom`

321 -> x -> pq (K LibPQ.Result ys)

329 -> x -> pq (K LibPQ.Result ys)

322 manipulateParams manipulation params = lift $

330 manipulateParams manipulation params = lift $

323 manipulateParams manipulation params

331 manipulateParams manipulation params

324

332

333+ manipulateParams_

334+ :: (ToParams x params, All OidOfParam params)

335+ => Manipulation '[] schemas params '[]

336+ -- ^ `insertInto`, `update` or `deleteFrom`

337+ -> x -> pq ()

338+ manipulateParams_ q x = void $ manipulateParams q x

339+

325− manipulate :: Manipulation schema '[] ys -> pq (K LibPQ.Result ys)

340+ manipulate :: Manipulation '[] schemas '[] ys -> pq (K LibPQ.Result ys)

326 manipulate statement = manipulateParams statement ()

341 manipulate statement = manipulateParams statement ()

327

342

343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()

344+ manipulate_ = void . manipulate

345+

328 runQueryParams

346 runQueryParams

329− :: ToParams x params

347+ :: (ToParams x params, All OidOfParam params)

330− => Query schema params ys

348+ => Query '[] '[] schemas params ys

331 -- ^ `select` and friends

349 -- ^ `select` and friends

332 -> x -> pq (K LibPQ.Result ys)

350 -> x -> pq (K LibPQ.Result ys)

333 runQueryParams = manipulateParams . queryStatement

351 runQueryParams = manipulateParams . queryStatement

334

352

335 runQuery

353 runQuery

336− :: Query schema '[] ys

354+ :: Query '[] '[] schemas '[] ys

337 -- ^ `select` and friends

355 -- ^ `select` and friends

338 -> pq (K LibPQ.Result ys)

356 -> pq (K LibPQ.Result ys)

339 runQuery q = runQueryParams q ()

357 runQuery q = runQueryParams q ()

340

358

341 traversePrepared

359 traversePrepared

342− :: (ToParams x params, Traversable list)

360+ :: (ToParams x params, Traversable list, All OidOfParam params)

343− => Manipulation schema params ys

361+ => Manipulation '[] schemas params ys

344− -- ^ `insertRows`, `update`, or `deleteFrom`, and friends

362+ -- ^ `insertInto`, `update`, or `deleteFrom`, and friends

345 -> list x -> pq (list (K LibPQ.Result ys))

363 -> list x -> pq (list (K LibPQ.Result ys))

346 default traversePrepared

364 default traversePrepared

347− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

365+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

348− => (ToParams x params, Traversable list)

366+ => (ToParams x params, Traversable list, All OidOfParam params)

349− => Manipulation schema params ys -> list x -> pq (list (K LibPQ.Result ys))

367+ => Manipulation '[] schemas params ys -> list x -> pq (list (K LibPQ.Result ys))

350 traversePrepared manipulation params = lift $

368 traversePrepared manipulation params = lift $

351 traversePrepared manipulation params

369 traversePrepared manipulation params

352

370

353 forPrepared

371 forPrepared

354− :: (ToParams x params, Traversable list)

372+ :: (ToParams x params, Traversable list, All OidOfParam params)

355 => list x

373 => list x

356− -> Manipulation schema params ys

374+ -> Manipulation '[] schemas params ys

357− -- ^ `insertRows`, `update` or `deleteFrom`

375+ -- ^ `insertInto`, `update` or `deleteFrom`

358 -> pq (list (K LibPQ.Result ys))

376 -> pq (list (K LibPQ.Result ys))

359 forPrepared = flip traversePrepared

377 forPrepared = flip traversePrepared

360

378

361 traversePrepared_

379 traversePrepared_

362− :: (ToParams x params, Foldable list)

380+ :: (ToParams x params, Foldable list, All OidOfParam params)

363− => Manipulation schema params '[]

381+ => Manipulation '[] schemas params '[]

364− -- ^ `insertRows`, `update` or `deleteFrom`

382+ -- ^ `insertInto`, `update` or `deleteFrom`

365 -> list x -> pq ()

383 -> list x -> pq ()

366 default traversePrepared_

384 default traversePrepared_

367− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

385+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

368− => (ToParams x params, Foldable list)

386+ => (ToParams x params, Foldable list, All OidOfParam params)

369− => Manipulation schema params '[]

387+ => Manipulation '[] schemas params '[]

370− -- ^ `insertRows`, `update` or `deleteFrom`

388+ -- ^ `insertInto`, `update` or `deleteFrom`

371 -> list x -> pq ()

389 -> list x -> pq ()

372 traversePrepared_ manipulation params = lift $

390 traversePrepared_ manipulation params = lift $

373 traversePrepared_ manipulation params

391 traversePrepared_ manipulation params

374

392

375 forPrepared_

393 forPrepared_

376− :: (ToParams x params, Foldable list)

394+ :: (ToParams x params, Foldable list, All OidOfParam params)

377 => list x

395 => list x

378− -> Manipulation schema params '[]

396+ -> Manipulation '[] schemas params '[]

379− -- ^ `insertRows`, `update` or `deleteFrom`

397+ -- ^ `insertInto`, `update` or `deleteFrom`

380 -> pq ()

398 -> pq ()

381 forPrepared_ = flip traversePrepared_

399 forPrepared_ = flip traversePrepared_

382

400

383 liftPQ :: (LibPQ.Connection -> IO a) -> pq a

401 liftPQ :: (LibPQ.Connection -> IO a) -> pq a

384 default liftPQ

402 default liftPQ

385− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

386 => (LibPQ.Connection -> IO a) -> pq a

404 => (LibPQ.Connection -> IO a) -> pq a

387 liftPQ = lift . liftPQ

405 liftPQ = lift . liftPQ

388

406

389−instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)

407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)

390− => MonadPQ schema (PQ schema0 schema1 io) where

408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where

391

409

392 manipulateParams

410 manipulateParams

393− (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =

411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =

394 PQ $ \ (K conn) -> do

412 PQ $ \ (K conn) -> do

395 let

413 let

396− toParam' bytes = (LibPQ.invalidOid,bytes,LibPQ.Binary)

414+ paramSet

415+ :: forall param. OidOfParam param

416+ => K (Maybe Encoding.Encoding) param

417+ -> K (Maybe (LibPQ.Oid, ByteString, LibPQ.Format)) param

418+ paramSet (K maybeEncoding) = K $

419+ maybeEncoding <&> \encoding ->

420+ (oidOfParam @param, encodingBytes encoding, LibPQ.Binary)

421+ params'

422+ = hcollapse

423+ . hcmap (Proxy @OidOfParam) paramSet

397− params' = fmap (fmap toParam') (hcollapse (toParams @x @ps params))

424+ $ toParams @x @ps params

398 q' = q <> ";"

425 q' = q <> ";"

399− resultMaybe <- liftBase $ LibPQ.execParams conn q' params' LibPQ.Binary

426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary

400 case resultMaybe of

427 case resultMaybe of

401− Nothing -> error

428+ Nothing -> throw $ ResultException

402 "manipulateParams: LibPQ.execParams returned no results"

429 "manipulateParams: LibPQ.execParams returned no results"

430+ Just result -> do

431+ okResult_ result

403− Just result -> return $ K (K result)

432+ return $ K (K result)

404

433

405 traversePrepared

434 traversePrepared

406− (UnsafeManipulation q :: Manipulation schema xs ys) (list :: list x) =

435+ (UnsafeManipulation q :: Manipulation '[] schemas xs ys) (list :: list x) =

407− PQ $ \ (K conn) -> liftBase $ do

436+ PQ $ \ (K conn) -> liftIO $ do

437+ let

408− let temp = "temporary_statement"

438+ temp = "temporary_statement"

439+ paramOid :: forall p. OidOfParam p => K LibPQ.Oid p

440+ paramOid = K (oidOfParam @p)

441+ paramOids :: NP (K LibPQ.Oid) xs

442+ paramOids = hcpure (Proxy @OidOfParam) paramOid

443+ paramOids' :: [LibPQ.Oid]

444+ paramOids' = hcollapse paramOids

409− prepResultMaybe <- LibPQ.prepare conn temp q Nothing

445+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

410 case prepResultMaybe of

446 case prepResultMaybe of

411− Nothing -> error

447+ Nothing -> throw $ ResultException

412 "traversePrepared: LibPQ.prepare returned no results"

448 "traversePrepared: LibPQ.prepare returned no results"

413− Just prepResult -> do

449+ Just prepResult -> okResult_ prepResult

414− status <- LibPQ.resultStatus prepResult

415− unless (status == LibPQ.CommandOk) . error $

416− "traversePrepared: LibPQ.prepare status " <> show status

417 results <- for list $ \ params -> do

450 results <- for list $ \ params -> do

418 let

451 let

419− toParam' bytes = (bytes,LibPQ.Binary)

452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

420 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

453 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

421 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

454 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

422 case resultMaybe of

455 case resultMaybe of

423− Nothing -> error

456+ Nothing -> throw $ ResultException

424 "traversePrepared: LibPQ.execParams returned no results"

457 "traversePrepared: LibPQ.execParams returned no results"

458+ Just result -> do

459+ okResult_ result

425− Just result -> return $ K result

460+ return $ K result

426 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

427 case deallocResultMaybe of

462 case deallocResultMaybe of

428− Nothing -> error

463+ Nothing -> throw $ ResultException

429 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

430− Just deallocResult -> do

465+ Just deallocResult -> okResult_ deallocResult

431− status <- LibPQ.resultStatus deallocResult

432− unless (status == LibPQ.CommandOk) . error $

433− "traversePrepared: DEALLOCATE status " <> show status

434 return (K results)

466 return (K results)

435

467

436 traversePrepared_

468 traversePrepared_

437− (UnsafeManipulation q :: Manipulation schema xs '[]) (list :: list x) =

469+ (UnsafeManipulation q :: Manipulation '[] schemas xs '[]) (list :: list x) =

438− PQ $ \ (K conn) -> liftBase $ do

470+ PQ $ \ (K conn) -> liftIO $ do

471+ let

439− let temp = "temporary_statement"

472+ temp = "temporary_statement"

473+ paramOid :: forall p. OidOfParam p => K LibPQ.Oid p

474+ paramOid = K (oidOfParam @p)

475+ paramOids :: NP (K LibPQ.Oid) xs

476+ paramOids = hcpure (Proxy @OidOfParam) paramOid

477+ paramOids' :: [LibPQ.Oid]

478+ paramOids' = hcollapse paramOids

440− prepResultMaybe <- LibPQ.prepare conn temp q Nothing

479+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

441 case prepResultMaybe of

480 case prepResultMaybe of

442− Nothing -> error

481+ Nothing -> throw $ ResultException

443 "traversePrepared_: LibPQ.prepare returned no results"

482 "traversePrepared_: LibPQ.prepare returned no results"

444− Just prepResult -> do

483+ Just prepResult -> okResult_ prepResult

445− status <- LibPQ.resultStatus prepResult

446− unless (status == LibPQ.CommandOk) . error $

447− "traversePrepared: LibPQ.prepare status " <> show status

448 for_ list $ \ params -> do

484 for_ list $ \ params -> do

449 let

485 let

450− toParam' bytes = (bytes,LibPQ.Binary)

486+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

451 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

487 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

452 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

488 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

453 case resultMaybe of

489 case resultMaybe of

454− Nothing -> error

490+ Nothing -> throw $ ResultException

455 "traversePrepared_: LibPQ.execParams returned no results"

491 "traversePrepared_: LibPQ.execParams returned no results"

456− Just _result -> return ()

492+ Just result -> okResult_ result

457 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

493 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

458 case deallocResultMaybe of

494 case deallocResultMaybe of

459− Nothing -> error

495+ Nothing -> throw $ ResultException

460 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

496 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

461− Just deallocResult -> do

497+ Just deallocResult -> okResult_ deallocResult

462− status <- LibPQ.resultStatus deallocResult

463− unless (status == LibPQ.CommandOk) . error $

464− "traversePrepared: DEALLOCATE status " <> show status

465 return (K ())

498 return (K ())

466

499

467 liftPQ pq = PQ $ \ (K conn) -> do

500 liftPQ pq = PQ $ \ (K conn) -> do

468− y <- liftBase $ pq conn

501+ y <- liftIO $ pq conn

469 return (K y)

502 return (K y)

470

503

471−instance MonadPQ schema m => MonadPQ schema (IdentityT m)

504+instance MonadPQ schemas m => MonadPQ schemas (IdentityT m)

472−instance MonadPQ schema m => MonadPQ schema (ReaderT r m)

505+instance MonadPQ schemas m => MonadPQ schemas (ReaderT r m)

473−instance MonadPQ schema m => MonadPQ schema (Strict.StateT s m)

506+instance MonadPQ schemas m => MonadPQ schemas (Strict.StateT s m)

474−instance MonadPQ schema m => MonadPQ schema (Lazy.StateT s m)

507+instance MonadPQ schemas m => MonadPQ schemas (Lazy.StateT s m)

475−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.WriterT w m)

508+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.WriterT w m)

476−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.WriterT w m)

509+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.WriterT w m)

477−instance MonadPQ schema m => MonadPQ schema (MaybeT m)

510+instance MonadPQ schemas m => MonadPQ schemas (MaybeT m)

478−instance MonadPQ schema m => MonadPQ schema (ExceptT e m)

511+instance MonadPQ schemas m => MonadPQ schemas (ExceptT e m)

479−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Strict.RWST r w s m)

512+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.RWST r w s m)

480−instance (Monoid w, MonadPQ schema m) => MonadPQ schema (Lazy.RWST r w s m)

513+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.RWST r w s m)

481−instance MonadPQ schema m => MonadPQ schema (ContT r m)

514+instance MonadPQ schemas m => MonadPQ schemas (ContT r m)

482−instance MonadPQ schema m => MonadPQ schema (ListT m)

515+

483−

484−instance (Monad m, schema0 ~ schema1)

516+instance (Monad m, schemas0 ~ schemas1)

485− => Applicative (PQ schema0 schema1 m) where

517+ => Applicative (PQ schemas0 schemas1 m) where

486 pure x = PQ $ \ _conn -> pure (K x)

518 pure x = PQ $ \ _conn -> pure (K x)

487 (<*>) = pqAp

519 (<*>) = pqAp

488

520

489−instance (Monad m, schema0 ~ schema1)

521+instance (Monad m, schemas0 ~ schemas1)

490− => Monad (PQ schema0 schema1 m) where

522+ => Monad (PQ schemas0 schemas1 m) where

491 return = pure

523 return = pure

492 (>>=) = flip pqBind

524 (>>=) = flip pqBind

493

525

494−instance schema0 ~ schema1 => MFunctor (PQ schema0 schema1) where

526+instance (Monad m, schemas0 ~ schemas1)

527+ => Fail.MonadFail (PQ schemas0 schemas1 m) where

528+ fail = Fail.fail

529+

530+instance schemas0 ~ schemas1 => MFunctor (PQ schemas0 schemas1) where

495 hoist f (PQ pq) = PQ (f . pq)

531 hoist f (PQ pq) = PQ (f . pq)

496

532

497−instance schema0 ~ schema1 => MonadTrans (PQ schema0 schema1) where

533+instance schemas0 ~ schemas1 => MonadTrans (PQ schemas0 schemas1) where

498 lift m = PQ $ \ _conn -> do

534 lift m = PQ $ \ _conn -> do

499 x <- m

535 x <- m

500 return (K x)

536 return (K x)

501

537

502−instance schema0 ~ schema1 => MMonad (PQ schema0 schema1) where

538+instance schemas0 ~ schemas1 => MMonad (PQ schemas0 schemas1) where

503 embed f (PQ pq) = PQ $ \ conn -> do

539 embed f (PQ pq) = PQ $ \ conn -> do

504 evalPQ (f (pq conn)) conn

540 evalPQ (f (pq conn)) conn

505

541

506−instance (MonadBase b m, schema0 ~ schema1)

542+instance (MonadIO m, schema0 ~ schema1)

507− => MonadBase b (PQ schema0 schema1 m) where

543+ => MonadIO (PQ schema0 schema1 m) where

508− liftBase = lift . liftBase

544+ liftIO = lift . liftIO

509

545

510−-- | A snapshot of the state of a `PQ` computation.

546+instance (MonadUnliftIO m, schemas0 ~ schemas1)

511−type PQRun schema =

547+ => MonadUnliftIO (PQ schemas0 schemas1 m) where

512− forall m x. Monad m => PQ schema schema m x -> m (K x schema)

548+ withRunInIO

513−

549+ :: ((forall a . PQ schemas0 schema1 m a -> IO a) -> IO b)

514−-- | Helper function in defining `MonadBaseControl` instance for `PQ`.

550+ -> PQ schemas0 schema1 m b

515−pqliftWith :: Functor m => (PQRun schema -> m a) -> PQ schema schema m a

551+ withRunInIO inner = PQ $ \conn ->

516−pqliftWith f = PQ $ \ conn ->

552+ withRunInIO $ \(run :: (forall x . m x -> IO x)) ->

517− fmap K (f $ \ pq -> unPQ pq conn)

553+ K <$> inner (\pq -> run $ unK <$> unPQ pq conn)

518−

519−instance (MonadBaseControl b m, schema0 ~ schema1)

520− => MonadBaseControl b (PQ schema0 schema1 m) where

521− type StM (PQ schema0 schema1 m) x = StM m (K x schema0)

522− liftBaseWith f =

523− pqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

524− restoreM = PQ . const . restoreM

525

554

526-- | Get a row corresponding to a given row number from a `LibPQ.Result`,

555-- | Get a row corresponding to a given row number from a `LibPQ.Result`,

527-- throwing an exception if the row number is out of bounds.

556-- throwing an exception if the row number is out of bounds.

528getRow

557getRow

529− :: (FromRow columns y, MonadBase IO io)

558+ :: (FromRow columns y, MonadIO io)

530 => LibPQ.Row

559 => LibPQ.Row

531 -- ^ row number

560 -- ^ row number

532 -> K LibPQ.Result columns

561 -> K LibPQ.Result columns

533 -- ^ result

562 -- ^ result

534 -> io y

563 -> io y

535−getRow r (K result :: K LibPQ.Result columns) = liftBase $ do

564+getRow r (K result :: K LibPQ.Result columns) = liftIO $ do

536 numRows <- LibPQ.ntuples result

565 numRows <- LibPQ.ntuples result

537− when (numRows < r) $ error $

566+ when (numRows < r) $ throw $ ResultException $

538− "getRow: expected at least " <> show r <> "rows but only saw "

567+ "getRow: expected at least " <> pack (show r) <> "rows but only saw "

539− <> show numRows

568+ <> pack (show numRows)

540 let len = fromIntegral (lengthSList (Proxy @columns))

569 let len = fromIntegral (lengthSList (Proxy @columns))

541 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

570 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

542 case fromList row' of

571 case fromList row' of

543− Nothing -> error "getRow: found unexpected length"

572+ Nothing -> throw $ ResultException "getRow: found unexpected length"

544− Just row -> return $ fromRow @columns row

573+ Just row -> case fromRow @columns row of

574+ Left parseError -> throw $ ParseException $ "getRow: " <> parseError

575+ Right y -> return y

545

576

546-- | Intended to be used for unfolding in streaming libraries, `nextRow`

577-- | Intended to be used for unfolding in streaming libraries, `nextRow`

547-- takes a total number of rows (which can be found with `ntuples`)

578-- takes a total number of rows (which can be found with `ntuples`)

548-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,

579-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,

549-- otherwise returning the row along with the next row number.

580-- otherwise returning the row along with the next row number.

550nextRow

581nextRow

551− :: (FromRow columns y, MonadBase IO io)

582+ :: (FromRow columns y, MonadIO io)

552 => LibPQ.Row -- ^ total number of rows

583 => LibPQ.Row -- ^ total number of rows

553 -> K LibPQ.Result columns -- ^ result

584 -> K LibPQ.Result columns -- ^ result

554 -> LibPQ.Row -- ^ row number

585 -> LibPQ.Row -- ^ row number

555 -> io (Maybe (LibPQ.Row,y))

586 -> io (Maybe (LibPQ.Row,y))

556nextRow total (K result :: K LibPQ.Result columns) r

587nextRow total (K result :: K LibPQ.Result columns) r

557− = liftBase $ if r >= total then return Nothing else do

588+ = liftIO $ if r >= total then return Nothing else do

558 let len = fromIntegral (lengthSList (Proxy @columns))

589 let len = fromIntegral (lengthSList (Proxy @columns))

559 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

590 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

560 case fromList row' of

591 case fromList row' of

561− Nothing -> error "nextRow: found unexpected length"

592+ Nothing -> throw $ ResultException "nextRow: found unexpected length"

593+ Just row -> case fromRow @columns row of

594+ Left parseError -> throw $ ParseException $ "nextRow: " <> parseError

562− Just row -> return $ Just (r+1, fromRow @columns row)

595+ Right y -> return $ Just (r+1, y)

563

596

564-- | Get all rows from a `LibPQ.Result`.

597-- | Get all rows from a `LibPQ.Result`.

565getRows

598getRows

566− :: (FromRow columns y, MonadBase IO io)

599+ :: (FromRow columns y, MonadIO io)

567 => K LibPQ.Result columns -- ^ result

600 => K LibPQ.Result columns -- ^ result

568 -> io [y]

601 -> io [y]

569−getRows (K result :: K LibPQ.Result columns) = liftBase $ do

602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do

570 let len = fromIntegral (lengthSList (Proxy @columns))

603 let len = fromIntegral (lengthSList (Proxy @columns))

571 numRows <- LibPQ.ntuples result

604 numRows <- LibPQ.ntuples result

572 for [0 .. numRows - 1] $ \ r -> do

605 for [0 .. numRows - 1] $ \ r -> do

573 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

606 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

574 case fromList row' of

607 case fromList row' of

575− Nothing -> error "getRows: found unexpected length"

608+ Nothing -> throw $ ResultException "getRows: found unexpected length"

576− Just row -> return $ fromRow @columns row

609+ Just row -> case fromRow @columns row of

610+ Left parseError -> throw $ ParseException $ "getRows: " <> parseError

611+ Right y -> return y

577

612

578-- | Get the first row if possible from a `LibPQ.Result`.

613-- | Get the first row if possible from a `LibPQ.Result`.

579firstRow

614firstRow

580− :: (FromRow columns y, MonadBase IO io)

615+ :: (FromRow columns y, MonadIO io)

581 => K LibPQ.Result columns -- ^ result

616 => K LibPQ.Result columns -- ^ result

582 -> io (Maybe y)

617 -> io (Maybe y)

583−firstRow (K result :: K LibPQ.Result columns) = liftBase $ do

618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do

584 numRows <- LibPQ.ntuples result

619 numRows <- LibPQ.ntuples result

585 if numRows <= 0 then return Nothing else do

620 if numRows <= 0 then return Nothing else do

586 let len = fromIntegral (lengthSList (Proxy @columns))

621 let len = fromIntegral (lengthSList (Proxy @columns))

587 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]

622 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]

588 case fromList row' of

623 case fromList row' of

589− Nothing -> error "firstRow: found unexpected length"

624+ Nothing -> throw $ ResultException "firstRow: found unexpected length"

590− Just row -> return . Just $ fromRow @columns row

625+ Just row -> case fromRow @columns row of

626+ Left parseError -> throw $ ParseException $ "firstRow: " <> parseError

627+ Right y -> return $ Just y

591

628

592-- | Lifts actions on results from @LibPQ@.

629-- | Lifts actions on results from @LibPQ@.

593liftResult

630liftResult

594− :: MonadBase IO io

631+ :: MonadIO io

595 => (LibPQ.Result -> IO x)

632 => (LibPQ.Result -> IO x)

596 -> K LibPQ.Result results -> io x

633 -> K LibPQ.Result results -> io x

597−liftResult f (K result) = liftBase $ f result

634+liftResult f (K result) = liftIO $ f result

598

635

599-- | Returns the number of rows (tuples) in the query result.

636-- | Returns the number of rows (tuples) in the query result.

600−ntuples :: MonadBase IO io => K LibPQ.Result columns -> io LibPQ.Row

637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row

601ntuples = liftResult LibPQ.ntuples

638ntuples = liftResult LibPQ.ntuples

602

639

603-- | Returns the result status of the command.

640-- | Returns the result status of the command.

604−resultStatus :: MonadBase IO io => K LibPQ.Result results -> io LibPQ.ExecStatus

641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus

605resultStatus = liftResult LibPQ.resultStatus

642resultStatus = liftResult LibPQ.resultStatus

606

643

607-- | Returns the error message most recently generated by an operation

644-- | Returns the error message most recently generated by an operation

608-- on the connection.

645-- on the connection.

609resultErrorMessage

646resultErrorMessage

610− :: MonadBase IO io => K LibPQ.Result results -> io (Maybe ByteString)

647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)

611resultErrorMessage = liftResult LibPQ.resultErrorMessage

648resultErrorMessage = liftResult LibPQ.resultErrorMessage

649+

650+-- | Returns the error code most recently generated by an operation

651+-- on the connection.

652+--

653+-- https://www.postgresql.org/docs/current/static/errcodes-appendix.html

654+resultErrorCode

655+ :: MonadIO io

656+ => K LibPQ.Result results

657+ -> io (Maybe ByteString)

658+resultErrorCode = liftResult (flip LibPQ.resultErrorField LibPQ.DiagSqlstate)

659+

660+-- | the state of LibPQ

661+data PQState = PQState

662+ { sqlExecStatus :: LibPQ.ExecStatus

663+ , sqlStateCode :: Maybe ByteString

664+ -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html

665+ , sqlErrorMessage :: Maybe ByteString

666+ } deriving (Eq, Show)

667+

668+-- | `Exception`s that can be thrown by Squeal.

669+data SquealException

670+ = PQException PQState

671+ | ResultException Text

672+ | ParseException Text

673+ deriving (Eq, Show)

674+instance Exception SquealException

675+

676+okResult_ :: MonadIO io => LibPQ.Result -> io ()

677+okResult_ result = liftIO $ do

678+ status <- LibPQ.resultStatus result

679+ case status of

680+ LibPQ.CommandOk -> return ()

681+ LibPQ.TuplesOk -> return ()

682+ _ -> do

683+ stateCode <- LibPQ.resultErrorField result LibPQ.DiagSqlstate

684+ msg <- LibPQ.resultErrorMessage result

685+ throw . PQException $ PQState status stateCode msg

686+

687+-- | Check if a `LibPQ.Result`'s status is either `LibPQ.CommandOk`

688+-- or `LibPQ.TuplesOk` otherwise `throw` a `PQException`.

689+okResult :: MonadIO io => K LibPQ.Result row -> io ()

690+okResult = okResult_ . unK

691+

692+-- | Catch `SquealException`s.

693+catchSqueal

694+ :: MonadUnliftIO io

695+ => io a

696+ -> (SquealException -> io a) -- ^ handler

697+ -> io a

698+catchSqueal = catch

699+

700+-- | Handle `SquealException`s.

701+handleSqueal

702+ :: MonadUnliftIO io

703+ => (SquealException -> io a) -- ^ handler

704+ -> io a -> io a

705+handleSqueal = handle

706+

707+-- | `Either` return a `SquealException` or a result.

708+trySqueal

709+ :: MonadUnliftIO io

710+ => io a

711+ -> io (Either SquealException a)

712+trySqueal = try

squeal-postgresql/src/Squeal/PostgreSQL/Pool.hs+69−79

@@ -1,17 +1,40 @@

1{-|

2−Module: Squeal.PostgreSQL.Definition

2+Module: Squeal.PostgreSQL.Pool

3−Description: Pooled connections

3+Description: Connection pools

4Copyright: (c) Eitan Chatav, 2017

5Maintainer: eitan@morphism.tech

6Stability: 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

9-}

31-}

11{-# LANGUAGE

33{-# LANGUAGE

12 DeriveFunctor

34 DeriveFunctor

13 , FlexibleContexts

35 , FlexibleContexts

14 , FlexibleInstances

36 , FlexibleInstances

37+ , InstanceSigs

15 , MultiParamTypeClasses

38 , MultiParamTypeClasses

16 , RankNTypes

39 , RankNTypes

17 , ScopedTypeVariables

40 , ScopedTypeVariables

@@ -22,34 +45,24 @@ A `MonadPQ` for pooled connections.

23module Squeal.PostgreSQL.Pool

46module Squeal.PostgreSQL.Pool

24 ( -- * Pools

47 ( -- * Pools

25− PoolPQ (..)

48+ Pool

26 , createConnectionPool

49 , createConnectionPool

27− , Pool

50+ , usingConnectionPool

28− , destroyAllResources

51+ , destroyConnectionPool

29− , PoolPQRun

30− , poolpqliftWith

31 ) where

52 ) where

33−import Control.Monad.Base

34−import Control.Monad.Trans

35−import Control.Monad.Trans.Control

36import Data.ByteString

54import Data.ByteString

37−import Data.Pool

38import Data.Time

55import Data.Time

39−import Generics.SOP (K(..))

56+import Generics.SOP (K(..), unK)

57+import UnliftIO (MonadUnliftIO (..))

58+import UnliftIO.Pool (Pool, createPool, destroyAllResources, withResource)

41import Squeal.PostgreSQL.PQ

60import Squeal.PostgreSQL.PQ

42−import Squeal.PostgreSQL.Schema

43−

44−-- | `PoolPQ` @schema@ should be a drop-in replacement for `PQ` @schema schema@.

45−newtype PoolPQ (schema :: SchemaType) m x =

46− PoolPQ { runPoolPQ :: Pool (K Connection schema) -> m x }

47− deriving Functor

49-- | Create a striped pool of connections.

62-- | Create a striped pool of connections.

50-- Although the garbage collector will destroy all idle connections when the pool is garbage collected it's recommended to manually `destroyAllResources` when you're done with the pool so that the connections are freed up as soon as possible.

63-- Although the garbage collector will destroy all idle connections when the pool is garbage collected it's recommended to manually `destroyAllResources` when you're done with the pool so that the connections are freed up as soon as possible.

51createConnectionPool

64createConnectionPool

52− :: MonadBase IO io

65+ :: MonadUnliftIO io

53 => ByteString

66 => ByteString

54 -- ^ The passed string can be empty to use all default parameters, or it can

67 -- ^ The passed string can be empty to use all default parameters, or it can

55 -- contain one or more parameter settings separated by whitespace.

68 -- contain one or more parameter settings separated by whitespace.

@@ -65,68 +78,45 @@ createConnectionPool

65 -> Int

78 -> Int

66 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

79 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

67 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

80 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

68− -> io (Pool (K Connection schema))

81+ -> io (Pool (K Connection schemas))

69−createConnectionPool conninfo stripes idle maxResrc = liftBase $

82+createConnectionPool conninfo stripes idle maxResrc =

70 createPool (connectdb conninfo) finish stripes idle maxResrc

83 createPool (connectdb conninfo) finish stripes idle maxResrc

72−-- | `Applicative` instance for `PoolPQ`.

85+{-|

73−instance Monad m => Applicative (PoolPQ schema m) where

86+Temporarily take a connection from a `Pool`, perform an action with it,

74− pure x = PoolPQ $ \ _ -> pure x

87+and return it to the pool afterwards.

75− PoolPQ f <*> PoolPQ x = PoolPQ $ \ pool -> do

76− f' <- f pool

77− x' <- x pool

78− return $ f' x'

79−

80−-- | `Monad` instance for `PoolPQ`.

81−instance Monad m => Monad (PoolPQ schema m) where

82− return = pure

83− PoolPQ x >>= f = PoolPQ $ \ pool -> do

84− x' <- x pool

85− runPoolPQ (f x') pool

86−

87−-- | `MonadTrans` instance for `PoolPQ`.

88−instance MonadTrans (PoolPQ schema) where

89− lift m = PoolPQ $ \ _pool -> m

90−

91−-- | `MonadBase` instance for `PoolPQ`.

92−instance MonadBase b m => MonadBase b (PoolPQ schema m) where

93− liftBase = lift . liftBase

95−-- | `MonadPQ` instance for `PoolPQ`.

89+If the pool has an idle connection available, it is used immediately.

96−instance MonadBaseControl IO io => MonadPQ schema (PoolPQ schema io) where

90+Otherwise, if the maximum number of connections has not yet been reached,

97− manipulateParams manipulation params = PoolPQ $ \ pool -> do

91+a new connection is created and used.

98− withResource pool $ \ conn -> do

92+If the maximum number of connections has been reached, this function blocks

99− (K result :: K (K Result ys) schema) <- flip unPQ conn $

93+until a connection becomes available.

100− manipulateParams manipulation params

94+-}

101− return result

95+usingConnectionPool

102− traversePrepared manipulation params = PoolPQ $ \ pool ->

96+ :: MonadUnliftIO io

103− withResource pool $ \ conn -> do

97+ => Pool (K Connection schemas) -- ^ pool

104− (K result :: K (list (K Result ys)) schema) <- flip unPQ conn $

98+ -> PQ schemas schemas io x -- ^ session

105− traversePrepared manipulation params

99+ -> io x

106− return result

107− traversePrepared_ manipulation params = PoolPQ $ \ pool -> do

108− withResource pool $ \ conn -> do

109− (_ :: K () schema) <- flip unPQ conn $

110− traversePrepared_ manipulation params

111− return ()

112− liftPQ m = PoolPQ $ \ pool ->

113− withResource pool $ \ conn -> do

100+usingConnectionPool pool (PQ session) = unK <$> withResource pool session

114− (K result :: K result schema) <- flip unPQ conn $

115− liftPQ m

116− return result

117

101

118−-- | A snapshot of the state of a `PoolPQ` computation.

102+{- |

119−type PoolPQRun schema =

103+Destroy all connections in all stripes in the pool.

120− forall m x. Monad m => PoolPQ schema m x -> m x

104+Note that this will ignore any exceptions in the destroy function.

121

105

122−-- | Helper function in defining `MonadBaseControl` instance for `PoolPQ`.

106+This function is useful when you detect that all connections

123−poolpqliftWith :: Functor m => (PoolPQRun schema -> m a) -> PoolPQ schema m a

107+in the pool are broken. For example after a database has been

124−poolpqliftWith f = PoolPQ $ \ pool ->

108+restarted all connections opened before the restart will be broken.

125− (f $ \ pq -> runPoolPQ pq pool)

109+In that case it's better to close those connections so that

110+`usingConnectionPool` won't take a broken connection from the pool

111+but will open a new connection instead.

126

112

127−-- | `MonadBaseControl` instance for `PoolPQ`.

113+Another use-case for this function is that when you know you are done

128−instance MonadBaseControl b m => MonadBaseControl b (PoolPQ schema m) where

114+with the pool you can destroy all idle connections immediately

129− type StM (PoolPQ schema m) x = StM m x

115+instead of waiting on the garbage collector to destroy them,

130− liftBaseWith f =

116+thus freeing up those connections sooner.

131− poolpqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

117+-}

132− restoreM = PoolPQ . const . restoreM

118+destroyConnectionPool

119+ :: MonadUnliftIO io

120+ => Pool (K Connection schemas) -- ^ pool

121+ -> io ()

122+destroyConnectionPool = destroyAllResources

squeal-postgresql/src/Squeal/PostgreSQL/Query.hs+677−467

@@ -1,7 +1,7 @@

1{-|

2Module: Squeal.PostgreSQL.Query

3Description: Squeal queries

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

5Maintainer: eitan@morphism.tech

6Stability: experimental

@@ -9,76 +9,81 @@ Squeal queries.

9-}

11{-# LANGUAGE

12+ ConstraintKinds

12− DeriveGeneric

13+ , DeriveGeneric

13 , FlexibleContexts

14 , FlexibleContexts

15+ , FlexibleInstances

14 , GADTs

16 , GADTs

15 , GeneralizedNewtypeDeriving

17 , GeneralizedNewtypeDeriving

16 , LambdaCase

18 , LambdaCase

19+ , MultiParamTypeClasses

20+ , OverloadedLabels

17 , OverloadedStrings

21 , OverloadedStrings

22+ , QuantifiedConstraints

23+ , ScopedTypeVariables

18 , StandaloneDeriving

24 , StandaloneDeriving

25+ , TypeApplications

19 , TypeFamilies

26 , TypeFamilies

20 , TypeInType

27 , TypeInType

21 , TypeOperators

28 , TypeOperators

29+ , RankNTypes

30+ , UndecidableInstances

22−#-}

31+ #-}

24module Squeal.PostgreSQL.Query

33module Squeal.PostgreSQL.Query

25 ( -- * Queries

34 ( -- * Queries

26− Query (UnsafeQuery, renderQuery)

35+ Query_

27− , Query'

36+ , Query (..)

28− , QueryFrom (..)

37+ -- ** Select

29− , queryFrom

38+ , select

39+ , select_

40+ , selectDistinct

41+ , selectDistinct_

42+ , selectDistinctOn

43+ , selectDistinctOn_

44+ , Selection (..)

45+ -- ** Values

46+ , values

47+ , values_

48+ -- ** Set Operations

30 , union

49 , union

31 , unionAll

50 , unionAll

32 , intersect

51 , intersect

33 , intersectAll

52 , intersectAll

34 , except

53 , except

35 , exceptAll

54 , exceptAll

36− -- * Select

55+ -- ** With

37− , select

56+ , With (..)

38− , selectDistinct

57+ , CommonTableExpression (..)

39− , selectStar

58+ , withRecursive

40− , selectDistinctStar

41− , selectDotStar

42− , selectDistinctDotStar

43− , values

44− , values_

45 -- * Table Expressions

59 -- * Table Expressions

46 , TableExpression (..)

60 , TableExpression (..)

47− , renderTableExpression

48 , from

61 , from

49 , where_

62 , where_

50− , group

63+ , groupBy

51 , having

64 , having

52− , orderBy

53 , limit

65 , limit

54 , offset

66 , offset

55− -- * From

67+ -- * From Clauses

56 , FromClause (..)

68 , FromClause (..)

57 , table

69 , table

58 , subquery

70 , subquery

59 , view

71 , view

72+ , common

60 , crossJoin

73 , crossJoin

61 , innerJoin

74 , innerJoin

62 , leftOuterJoin

75 , leftOuterJoin

63 , rightOuterJoin

76 , rightOuterJoin

64 , fullOuterJoin

77 , fullOuterJoin

65 -- * Grouping

78 -- * Grouping

66− , By (By, By2)

79+ , By (..)

67− , renderBy

68− , GroupByClause (NoGroups, Group)

80+ , GroupByClause (..)

69− , renderGroupByClause

70− , HavingClause (NoHaving, Having)

81+ , HavingClause (..)

71− , renderHavingClause

72− -- * Sorting

73− , SortExpression (..)

74− , renderSortExpression

75 ) where

82 ) where

77import Control.DeepSeq

84import Control.DeepSeq

78import Data.ByteString (ByteString)

85import Data.ByteString (ByteString)

79−import Data.Kind

86+import Data.Kind (Type)

80−import Data.Monoid hiding (All)

81−import Data.Profunctor

82import Data.String

87import Data.String

83import Data.Word

88import Data.Word

84import Generics.SOP hiding (from)

89import Generics.SOP hiding (from)

@@ -86,26 +91,76 @@ import GHC.TypeLits

87import qualified GHC.Generics as GHC

92import qualified GHC.Generics as GHC

89−import Squeal.PostgreSQL.Binary

94+import Squeal.PostgreSQL.Alias

90import Squeal.PostgreSQL.Expression

95import Squeal.PostgreSQL.Expression

96+import Squeal.PostgreSQL.Expression.Logic

97+import Squeal.PostgreSQL.Expression.Sort

98+import Squeal.PostgreSQL.Expression.Window

99+import Squeal.PostgreSQL.List

100+import Squeal.PostgreSQL.PG

91import Squeal.PostgreSQL.Render

101import Squeal.PostgreSQL.Render

92import Squeal.PostgreSQL.Schema

102import Squeal.PostgreSQL.Schema

103

104+-- $setup

105+-- >>> import Squeal.PostgreSQL

106+-- >>> import Data.Int (Int32, Int64)

107+-- >>> import Data.Monoid (Sum (..))

108+-- >>> import Data.Text (Text)

109+-- >>> import qualified Generics.SOP as SOP

110+

111+{- |

112+The process of retrieving or the command to retrieve data from

113+a database is called a `Query`.

114+

115+The general `Query` type is parameterized by

116+

117+* @outer :: FromType@ - outer scope for a correlated subquery,

118+* @commons :: FromType@ - scope for all `common` table expressions,

119+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

120+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

121+* @row :: RowType@ - return type of the `Query`.

122+-}

123+newtype Query

124+ (outer :: FromType)

125+ (commons :: FromType)

126+ (schemas :: SchemasType)

127+ (params :: [NullityType])

128+ (row :: RowType)

129+ = UnsafeQuery { renderQuery :: ByteString }

130+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

131+instance RenderSQL (Query outer commons schemas params row) where renderSQL = renderQuery

132+

94{- |

133{- |

95−The process of retrieving or the command to retrieve data from a database

134+The top level `Query_` type is parameterized by a @schemas@ `SchemasType`,

96−is called a `Query`. The `select`, `selectStar`, `selectDotStar`,

135+against which the query is type-checked, an input @parameters@ Haskell `Type`,

97−`selectDistinct`, `selectDistinctStar` and `selectDistinctDotStar` commands

136+and an ouput row Haskell `Type`.

98−are used to specify queries.

137+

138+A top-level query can be run

139+using `Squeal.PostgreSQL.PQ.runQueryParams`, or if @parameters = ()@

140+using `Squeal.PostgreSQL.PQ.runQuery`.

141+

142+Generally, @parameters@ will be a Haskell tuple or record whose entries

143+may be referenced using positional

144+`Squeal.PostgreSQL.Expression.Parameter.parameter`s and @row@ will be a

145+Haskell record, whose entries will be targeted using overloaded labels.

146+

147+Let's see some examples of queries.

148+

149+>>> :set -XDeriveAnyClass -XDerivingStrategies

150+>>> :{

151+data Row a b = Row { col1 :: a, col2 :: b }

152+ deriving stock (GHC.Generic)

153+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

154+:}

155

100simple query:

156simple query:

101

157

158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

102>>> :{

160>>> :{

103let

161let

104− query :: Query

162+ query :: Query_ (Public Schema) () (Row Int32 Int32)

105− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

106− '[]

107− '["col" ::: 'Null 'PGint4]

108− query = selectStar (from (table #tab))

163+ query = select Star (from (table #tab))

109in printSQL query

164in printSQL query

110:}

165:}

111SELECT * FROM "tab" AS "tab"

166SELECT * FROM "tab" AS "tab"

@@ -114,34 +169,22 @@ restricted query:

114

169

115>>> :{

170>>> :{

116let

171let

117− query :: Query

172+ query :: Query_ (Public Schema) () (Row Int32 Int32)

118− '[ "tab" ::: 'Table ('[] :=>

119− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

120− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

121− '[]

122− '[ "sum" ::: 'NotNull 'PGint4

123− , "col1" ::: 'NotNull 'PGint4 ]

124 query =

173 query =

125− select

126− ((#col1 + #col2) `As` #sum :* #col1 :* Nil)

174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)

127 ( from (table #tab)

175 ( from (table #tab)

128 & where_ (#col1 .> #col2)

176 & where_ (#col1 .> #col2)

129 & where_ (#col2 .> 0) )

177 & where_ (#col2 .> 0) )

130in printSQL query

178in printSQL query

131:}

179:}

132−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))

133

181

134subquery:

182subquery:

135

183

136>>> :{

184>>> :{

137let

185let

138− query :: Query

186+ query :: Query_ (Public Schema) () (Row Int32 Int32)

139− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

140− '[]

141− '["col" ::: 'Null 'PGint4]

142− query =

143− selectStar

144− (from (subquery (selectStar (from (table #tab)) `As` #sub)))

187+ query = select Star (from (subquery (select Star (from (table #tab)) `as` #sub)))

145in printSQL query

188in printSQL query

146:}

189:}

147SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"

190SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"

@@ -150,12 +193,8 @@ limits and offsets:

150

193

151>>> :{

194>>> :{

152let

195let

153− query :: Query

196+ query :: Query_ (Public Schema) () (Row Int32 Int32)

154− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

155− '[]

156− '["col" ::: 'Null 'PGint4]

157− query = selectStar

158− (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)

197+ query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)

159in printSQL query

198in printSQL query

160:}

199:}

161SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4

200SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4

@@ -164,298 +203,426 @@ parameterized query:

164

203

165>>> :{

204>>> :{

166let

205let

167− query :: Query

206+ query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)

168− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8])]

169− '[ 'NotNull 'PGfloat8]

170− '["col" ::: 'NotNull 'PGfloat8]

171− query = selectStar

172− (from (table #tab) & where_ (#col .> param @1))

207+ query = select Star (from (table #tab) & where_ (#col1 .> param @1))

173in printSQL query

208in printSQL query

174:}

209:}

175−SELECT * FROM "tab" AS "tab" WHERE ("col" > ($1 :: float8))

210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))

176

211

177aggregation query:

212aggregation query:

178

213

179>>> :{

214>>> :{

180let

215let

181− query :: Query

216+ query :: Query_ (Public Schema) () (Row Int64 Int32)

182− '[ "tab" ::: 'Table ('[] :=>

183− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

184− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

185− '[]

186− '[ "sum" ::: 'NotNull 'PGint4

187− , "col1" ::: 'NotNull 'PGint4 ]

188 query =

217 query =

189− select (sum_ #col2 `As` #sum :* #col1 :* Nil)

218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)

190− ( from (table (#tab `As` #table1))

219+ ( from (table (#tab `as` #table1))

191− & group (By #col1 :* Nil)

220+ & groupBy #col1

192− & having (#col1 + sum_ #col2 .> 1) )

221+ & having (sum_ (Distinct #col2) .> 1) )

193in printSQL query

222in printSQL query

194:}

223:}

195−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)

196

225

197sorted query:

226sorted query:

198

227

199>>> :{

228>>> :{

200let

229let

201− query :: Query

230+ query :: Query_ (Public Schema) () (Row Int32 Int32)

202− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

203− '[]

204− '["col" ::: 'Null 'PGint4]

205− query = selectStar

206− (from (table #tab) & orderBy [#col & AscNullsFirst])

231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])

207in printSQL query

232in printSQL query

208:}

233:}

209−SELECT * FROM "tab" AS "tab" ORDER BY "col" ASC NULLS FIRST

234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC

210

235

211joins:

236joins:

212

237

213−>>> :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+

214>>> :{

273>>> :{

215let

274let

216− query :: Query

275+ query :: Query_ (Public OrdersSchema) () Order

217− '[ "orders" ::: 'Table (

218− '["pk_orders" ::: PrimaryKey '["id"]

219− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]

220− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>

221− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

222− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4

223− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4

224− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4

225− ])

226− , "customers" ::: 'Table (

227− '["pk_customers" ::: PrimaryKey '["id"]] :=>

228− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

229− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

230− ])

231− , "shippers" ::: 'Table (

232− '["pk_shippers" ::: PrimaryKey '["id"]] :=>

233− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

234− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

235− ])

236− ]

237− '[]

238− '[ "order_price" ::: 'NotNull 'PGfloat4

239− , "customer_name" ::: 'NotNull 'PGtext

240− , "shipper_name" ::: 'NotNull 'PGtext

241− ]

242− query = select

276+ query = select_

243− ( #o ! #price `As` #order_price :*

277+ ( #o ! #price `as` #price :*

244− #c ! #name `As` #customer_name :*

278+ #c ! #name `as` #customerName :*

245− #s ! #name `As` #shipper_name :* Nil )

279+ #s ! #name `as` #shipperName )

246− ( from (table (#orders `As` #o)

280+ ( from (table (#orders `as` #o)

247− & innerJoin (table (#customers `As` #c))

281+ & innerJoin (table (#customers `as` #c))

248 (#o ! #customer_id .== #c ! #id)

282 (#o ! #customer_id .== #c ! #id)

249− & innerJoin (table (#shippers `As` #s))

283+ & innerJoin (table (#shippers `as` #s))

250 (#o ! #shipper_id .== #s ! #id)) )

284 (#o ! #shipper_id .== #s ! #id)) )

251in printSQL query

285in printSQL query

252:}

286:}

253−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")

254

288

255self-join:

289self-join:

256

290

257>>> :{

291>>> :{

258let

292let

259− query :: Query

293+ query :: Query_ (Public Schema) () (Row Int32 Int32)

260− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

294+ query = select

261− '[]

295+ (#t1 & DotStar)

262− '["col" ::: 'Null 'PGint4]

263− query = selectDotStar #t1

264− (from (table (#tab `As` #t1) & crossJoin (table (#tab `As` #t2))))

296+ (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))

265in printSQL query

297in printSQL query

266:}

298:}

267SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"

299SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"

268

300

301+value queries:

302+

303+>>> :{

304+let

305+ query :: Query_ schemas () (Row String Bool)

306+ query = values

307+ ("true" `as` #col1 :* true `as` #col2)

308+ ["false" `as` #col1 :* false `as` #col2]

309+in printSQL query

310+:}

311+SELECT * FROM (VALUES (E'true', TRUE), (E'false', FALSE)) AS t ("col1", "col2")

312+

269set operations:

313set operations:

270

314

271>>> :{

315>>> :{

272let

316let

273− query :: Query

317+ query :: Query_ (Public Schema) () (Row Int32 Int32)

274− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

318+ query = select Star (from (table #tab)) `unionAll` select Star (from (table #tab))

275− '[]

276− '["col" ::: 'Null 'PGint4]

277− query =

278− selectStar (from (table #tab))

279− `unionAll`

280− selectStar (from (table #tab))

281in printSQL query

319in printSQL query

282:}

320:}

283(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")

321(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")

284−-}

285−newtype Query

286− (schema :: SchemaType)

287− (params :: [NullityType])

288− (columns :: RelationType)

289− = UnsafeQuery { renderQuery :: ByteString }

290− deriving (GHC.Generic,Show,Eq,Ord,NFData)

291−instance RenderSQL (Query schema params columns) where renderSQL = renderQuery

292

322

293−data QueryFrom

323+with queries:

294− (schema :: SchemaType)

324+

295− (x :: Type)

325+>>> :{

296− (y :: Type)

326+let

297− where

327+ query :: Query_ (Public Schema) () (Row Int32 Int32)

298− QueryFrom

328+ query = with (

299− :: (x -> NP (K (Maybe ByteString)) params)

329+ select Star (from (table #tab)) `as` #cte1 :>>

300− -> Query schema params result

330+ select Star (from (common #cte1)) `as` #cte2

301− -> (NP (K (Maybe ByteString)) result -> y)

331+ ) (select Star (from (common #cte2)))

302− -> QueryFrom schema x y

332+in printSQL query

303−instance Profunctor (QueryFrom schema) where

333+:}

304− dimap f g (QueryFrom params q result) = QueryFrom (params.f) q (g.result)

334+WITH "cte1" AS (SELECT * FROM "tab" AS "tab"), "cte2" AS (SELECT * FROM "cte1" AS "cte1") SELECT * FROM "cte2" AS "cte2"

305−

335+

306−queryFrom

336+window function queries

307− :: (ToParams x (ParamsFrom x), FromRow (ResultFrom y) y)

337+

308− => Query schema (ParamsFrom x) (ResultFrom y)

338+>>> :{

309− -> QueryFrom schema x y

339+let

310−queryFrom q = QueryFrom toParams q fromRow

340+ query :: Query_ (Public Schema) () (Row Int32 Int64)

311−

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+

362+-}

312−type family Query' schema x y where

363+type family Query_

313− Query' schema x y = Query schema (ParamsFrom x) (ResultFrom y)

364+ (schemas :: SchemasType)

365+ (parameters :: Type)

366+ (row :: Type) where

367+ Query_ schemas params row =

368+ Query '[] '[] schemas (TuplePG params) (RowPG row)

314

369

315-- | The results of two queries can be combined using the set operation

370-- | The results of two queries can be combined using the set operation

316-- `union`. Duplicate rows are eliminated.

371-- `union`. Duplicate rows are eliminated.

317union

372union

318− :: Query schema params columns

373+ :: Query outer commons schemas params columns

319− -> Query schema params columns

374+ -> Query outer commons schemas params columns

320− -> Query schema params columns

375+ -> Query outer commons schemas params columns

321q1 `union` q2 = UnsafeQuery $

376q1 `union` q2 = UnsafeQuery $

322− parenthesized (renderQuery q1)

377+ parenthesized (renderSQL q1)

323 <+> "UNION"

378 <+> "UNION"

324− <+> parenthesized (renderQuery q2)

379+ <+> parenthesized (renderSQL q2)

325

380

326-- | The results of two queries can be combined using the set operation

381-- | The results of two queries can be combined using the set operation

327-- `unionAll`, the disjoint union. Duplicate rows are retained.

382-- `unionAll`, the disjoint union. Duplicate rows are retained.

328unionAll

383unionAll

329− :: Query schema params columns

384+ :: Query outer commons schemas params columns

330− -> Query schema params columns

385+ -> Query outer commons schemas params columns

331− -> Query schema params columns

386+ -> Query outer commons schemas params columns

332q1 `unionAll` q2 = UnsafeQuery $

387q1 `unionAll` q2 = UnsafeQuery $

333− parenthesized (renderQuery q1)

388+ parenthesized (renderSQL q1)

334 <+> "UNION" <+> "ALL"

389 <+> "UNION" <+> "ALL"

335− <+> parenthesized (renderQuery q2)

390+ <+> parenthesized (renderSQL q2)

336

391

337-- | The results of two queries can be combined using the set operation

392-- | The results of two queries can be combined using the set operation

338-- `intersect`, the intersection. Duplicate rows are eliminated.

393-- `intersect`, the intersection. Duplicate rows are eliminated.

339intersect

394intersect

340− :: Query schema params columns

395+ :: Query outer commons schemas params columns

341− -> Query schema params columns

396+ -> Query outer commons schemas params columns

342− -> Query schema params columns

397+ -> Query outer commons schemas params columns

343q1 `intersect` q2 = UnsafeQuery $

398q1 `intersect` q2 = UnsafeQuery $

344− parenthesized (renderQuery q1)

399+ parenthesized (renderSQL q1)

345 <+> "INTERSECT"

400 <+> "INTERSECT"

346− <+> parenthesized (renderQuery q2)

401+ <+> parenthesized (renderSQL q2)

347

402

348-- | The results of two queries can be combined using the set operation

403-- | The results of two queries can be combined using the set operation

349-- `intersectAll`, the intersection. Duplicate rows are retained.

404-- `intersectAll`, the intersection. Duplicate rows are retained.

350intersectAll

405intersectAll

351− :: Query schema params columns

406+ :: Query outer commons schemas params columns

352− -> Query schema params columns

407+ -> Query outer commons schemas params columns

353− -> Query schema params columns

408+ -> Query outer commons schemas params columns

354q1 `intersectAll` q2 = UnsafeQuery $

409q1 `intersectAll` q2 = UnsafeQuery $

355− parenthesized (renderQuery q1)

410+ parenthesized (renderSQL q1)

356 <+> "INTERSECT" <+> "ALL"

411 <+> "INTERSECT" <+> "ALL"

357− <+> parenthesized (renderQuery q2)

412+ <+> parenthesized (renderSQL q2)

358

413

359-- | The results of two queries can be combined using the set operation

414-- | The results of two queries can be combined using the set operation

360-- `except`, the set difference. Duplicate rows are eliminated.

415-- `except`, the set difference. Duplicate rows are eliminated.

361except

416except

362− :: Query schema params columns

417+ :: Query outer commons schemas params columns

363− -> Query schema params columns

418+ -> Query outer commons schemas params columns

364− -> Query schema params columns

419+ -> Query outer commons schemas params columns

365q1 `except` q2 = UnsafeQuery $

420q1 `except` q2 = UnsafeQuery $

366− parenthesized (renderQuery q1)

421+ parenthesized (renderSQL q1)

367 <+> "EXCEPT"

422 <+> "EXCEPT"

368− <+> parenthesized (renderQuery q2)

423+ <+> parenthesized (renderSQL q2)

369

424

370-- | The results of two queries can be combined using the set operation

425-- | The results of two queries can be combined using the set operation

371-- `exceptAll`, the set difference. Duplicate rows are retained.

426-- `exceptAll`, the set difference. Duplicate rows are retained.

372exceptAll

427exceptAll

373− :: Query schema params columns

428+ :: Query outer commons schemas params columns

374− -> Query schema params columns

429+ -> Query outer commons schemas params columns

375− -> Query schema params columns

430+ -> Query outer commons schemas params columns

376q1 `exceptAll` q2 = UnsafeQuery $

431q1 `exceptAll` q2 = UnsafeQuery $

377− parenthesized (renderQuery q1)

432+ parenthesized (renderSQL q1)

378 <+> "EXCEPT" <+> "ALL"

433 <+> "EXCEPT" <+> "ALL"

379− <+> parenthesized (renderQuery q2)

434+ <+> parenthesized (renderSQL q2)

380

435

381{-----------------------------------------

436{-----------------------------------------

382SELECT queries

437SELECT queries

383-----------------------------------------}

438-----------------------------------------}

384

439

440+{- | The simplest kinds of `Selection` are `Star` and `DotStar` which

441+emits all columns that a `TableExpression` produces. A select `List`

442+is a list of `Expression`s. A `Selection` could be a list of

443+`WindowFunction`s `Over` `WindowDefinition`. `Additional` `Selection`s can

444+be selected with `Also`.

445+-}

446+data Selection outer commons grp schemas params from row where

447+ Star

448+ :: HasUnique tab from row

449+ => Selection outer commons 'Ungrouped schemas params from row

450+ -- ^ `HasUnique` table in the `FromClause`

451+ DotStar

452+ :: Has tab from row

453+ => Alias tab

454+ -- ^ `Has` table with `Alias`

455+ -> Selection outer commons 'Ungrouped schemas params from row

456+ List

457+ :: SListI row

458+ => NP (Aliased (Expression outer commons grp schemas params from)) row

459+ -- ^ `NP` list of `Aliased` `Expression`s

460+ -> Selection outer commons grp schemas params from row

461+ Over

462+ :: SListI row

463+ => NP (Aliased (WindowFunction outer commons grp schemas params from)) row

464+ -- ^ `NP` list of `Aliased` `WindowFunction`s

465+ -> WindowDefinition outer commons grp schemas params from

466+ -> Selection outer commons grp schemas params from row

467+ Also

468+ :: Selection outer commons grp schemas params from right

469+ -- ^ `Additional` `Selection`

470+ -> Selection outer commons grp schemas params from left

471+ -> Selection outer commons grp schemas params from (Join left right)

472+instance Additional (Selection outer commons grp schemas params from) where

473+ also = Also

474+instance (KnownSymbol col, row ~ '[col ::: ty])

475+ => Aliasable col

476+ (Expression outer commons grp schemas params from ty)

477+ (Selection outer commons grp schemas params from row) where

478+ expr `as` col = List (expr `as` col)

479+instance (Has tab (Join outer from) row0, Has col row0 ty, row1 ~ '[col ::: ty])

480+ => IsQualified tab col

481+ (Selection outer commons 'Ungrouped schemas params from row1) where

482+ tab ! col = tab ! col `as` col

483+instance

484+ ( Has tab (Join outer from) row0

485+ , Has col row0 ty

486+ , row1 ~ '[col ::: ty]

487+ , GroupedBy tab col bys )

488+ => IsQualified tab col

489+ (Selection outer commons ('Grouped bys) schemas params from row1) where

490+ tab ! col = tab ! col `as` col

491+instance (HasUnique tab (Join outer from) row0, Has col row0 ty, row1 ~ '[col ::: ty])

492+ => IsLabel col

493+ (Selection outer commons 'Ungrouped schemas params from row1) where

494+ fromLabel = fromLabel @col `as` Alias

495+instance

496+ ( HasUnique tab (Join outer from) row0

497+ , Has col row0 ty

498+ , row1 ~ '[col ::: ty]

499+ , GroupedBy tab col bys )

500+ => IsLabel col

501+ (Selection outer commons ('Grouped bys) schemas params from row1) where

502+ fromLabel = fromLabel @col `as` Alias

503+

504+instance RenderSQL (Selection outer commons grp schemas params from row) where

505+ renderSQL = \case

506+ List list -> renderCommaSeparated (renderAliased renderSQL) list

507+ Star -> "*"

508+ DotStar tab -> renderSQL tab <> ".*"

509+ Also right left -> renderSQL left <> ", " <> renderSQL right

510+ Over winFns winDef ->

511+ let

512+ renderOver

513+ :: Aliased (WindowFunction outer commons grp schemas params from) field

514+ -> ByteString

515+ renderOver (winFn `As` col) = renderSQL winFn

516+ <+> "OVER" <+> parenthesized (renderSQL winDef)

517+ <+> "AS" <+> renderSQL col

518+ in

519+ renderCommaSeparated renderOver winFns

520+

521+instance IsString

522+ (Selection outer commons grp schemas params from '["fromOnly" ::: 'NotNull 'PGtext]) where

523+ fromString str = fromString str `as` Alias

524+

385-- | the `TableExpression` in the `select` command constructs an intermediate

525-- | the `TableExpression` in the `select` command constructs an intermediate

386-- virtual table by possibly combining tables, views, eliminating rows,

526-- virtual table by possibly combining tables, views, eliminating rows,

387-- grouping, etc. This table is finally passed on to processing by

527-- grouping, etc. This table is finally passed on to processing by

388−-- the select list. The select list determines which columns of

528+-- the select list. The `Selection` determines which columns of

389-- the intermediate table are actually output.

529-- the intermediate table are actually output.

390select

530select

391− :: SListI columns

531+ :: (SListI row, row ~ (x ': xs))

392− => NP (Aliased (Expression schema relations grouping params)) (column ': columns)

532+ => Selection outer commons grp schemas params from row

393− -- ^ select list

533+ -- ^ selection

394− -> TableExpression schema params relations grouping

534+ -> TableExpression outer commons grp schemas params from

395 -- ^ intermediate virtual table

535 -- ^ intermediate virtual table

396− -> Query schema params (column ': columns)

536+ -> Query outer commons schemas params row

397−select list rels = UnsafeQuery $

537+select selection tabexpr = UnsafeQuery $

398 "SELECT"

538 "SELECT"

399− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

539+ <+> renderSQL selection

400− <+> renderTableExpression rels

540+ <+> renderSQL tabexpr

541+

542+-- | Like `select` but takes an `NP` list of `Expression`s instead

543+-- of a general `Selection`.

544+select_

545+ :: (SListI row, row ~ (x ': xs))

546+ => NP (Aliased (Expression outer commons grp schemas params from)) row

547+ -- ^ select list

548+ -> TableExpression outer commons grp schemas params from

549+ -- ^ intermediate virtual table

550+ -> Query outer commons schemas params row

551+select_ = select . List

401

552

402-- | After the select list has been processed, the result table can

553-- | After the select list has been processed, the result table can

403-- be subject to the elimination of duplicate rows using `selectDistinct`.

554-- be subject to the elimination of duplicate rows using `selectDistinct`.

404selectDistinct

555selectDistinct

405− :: SListI columns

556+ :: (SListI columns, columns ~ (col ': cols))

406− => NP (Aliased (Expression schema relations 'Ungrouped params)) (column ': columns)

557+ => Selection outer commons grp schemas params from columns

407− -- ^ select list

558+ -- ^ selection

408− -> TableExpression schema params relations 'Ungrouped

559+ -> TableExpression outer commons grp schemas params from

409 -- ^ intermediate virtual table

560 -- ^ intermediate virtual table

410− -> Query schema params (column ': columns)

561+ -> Query outer commons schemas params columns

411−selectDistinct list rels = UnsafeQuery $

562+selectDistinct selection tabexpr = UnsafeQuery $

412 "SELECT DISTINCT"

563 "SELECT DISTINCT"

413− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

564+ <+> renderSQL selection

414− <+> renderTableExpression rels

565+ <+> renderSQL tabexpr

415−

566+

416−-- | The simplest kind of query is `selectStar` which emits all columns

567+-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead

417−-- that the table expression produces.

568+-- of a general `Selection`.

418−selectStar

569+selectDistinct_

419− :: HasUnique relation relations columns

570+ :: (SListI columns, columns ~ (col ': cols))

420− => TableExpression schema params relations 'Ungrouped

571+ => NP (Aliased (Expression outer commons grp schemas params from)) columns

421− -- ^ intermediate virtual table

572+ -- ^ select list

422− -> Query schema params columns

573+ -> TableExpression outer commons grp schemas params from

423−selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels

424−

425−-- | A `selectDistinctStar` emits all columns that the table expression

426−-- produces and eliminates duplicate rows.

427−selectDistinctStar

428− :: HasUnique relation relations columns

429− => TableExpression schema params relations 'Ungrouped

430 -- ^ intermediate virtual table

574 -- ^ intermediate virtual table

431− -> Query schema params columns

575+ -> Query outer commons schemas params columns

432−selectDistinctStar rels = UnsafeQuery $

576+selectDistinct_ = selectDistinct . List

433− "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels

577+

434−

578+{-|

435−-- | When working with multiple tables, it can also be useful to ask

579+`selectDistinctOn` keeps only the first row of each set of rows where

436−-- for all the columns of a particular table, using `selectDotStar`.

580+the given expressions evaluate to equal. The DISTINCT ON expressions are

437−selectDotStar

581+interpreted using the same rules as for ORDER BY. ORDER BY is used to

438− :: Has relation relations columns

582+ensure that the desired row appears first.

439− => Alias relation

583+

440− -- ^ particular virtual subtable

584+The DISTINCT ON expression(s) must match the leftmost ORDER BY expression(s).

441− -> TableExpression schema params relations 'Ungrouped

585+The ORDER BY clause will normally contain additional expression(s) that

586+determine the desired precedence of rows within each DISTINCT ON group.

587+

588+In order to guarantee they match and reduce redundancy, this function

589+will prepend the The DISTINCT ON expressions to the ORDER BY clause.

590+-}

591+selectDistinctOn

592+ :: (SListI columns, columns ~ (col ': cols))

593+ => [SortExpression outer commons grp schemas params from]

594+ -- ^ DISTINCT ON expression(s) and prepended to ORDER BY clause

595+ -> Selection outer commons grp schemas params from columns

596+ -- ^ selection

597+ -> TableExpression outer commons grp schemas params from

442 -- ^ intermediate virtual table

598 -- ^ intermediate virtual table

443− -> Query schema params columns

599+ -> Query outer commons schemas params columns

444−selectDotStar rel relations = UnsafeQuery $

600+selectDistinctOn distincts selection tab = UnsafeQuery $

445− "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression relations

601+ "SELECT DISTINCT ON"

446−

602+ <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))

447−-- | A `selectDistinctDotStar` asks for all the columns of a particular table,

603+ <+> renderSQL selection

448−-- and eliminates duplicate rows.

604+ <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})

449−selectDistinctDotStar

605+ where

450− :: Has relation relations columns

606+ renderDistinctOn = \case

451− => Alias relation

607+ Asc expression -> renderSQL expression

452− -- ^ particular virtual table

608+ Desc expression -> renderSQL expression

453− -> TableExpression schema params relations 'Ungrouped

609+ AscNullsFirst expression -> renderSQL expression

610+ DescNullsFirst expression -> renderSQL expression

611+ AscNullsLast expression -> renderSQL expression

612+ DescNullsLast expression -> renderSQL expression

613+

614+-- | Like `selectDistinctOn` but takes an `NP` list of `Expression`s instead

615+-- of a general `Selection`.

616+selectDistinctOn_

617+ :: (SListI columns, columns ~ (col ': cols))

618+ => [SortExpression outer commons grp schemas params from]

619+ -- ^ distinct on and return the first row in ordering

620+ -> NP (Aliased (Expression outer commons grp schemas params from)) columns

621+ -- ^ selection

622+ -> TableExpression outer commons grp schemas params from

454 -- ^ intermediate virtual table

623 -- ^ intermediate virtual table

455− -> Query schema params columns

624+ -> Query outer commons schemas params columns

456−selectDistinctDotStar rel relations = UnsafeQuery $

625+selectDistinctOn_ distincts = selectDistinctOn distincts . List

457− "SELECT DISTINCT" <+> renderAlias rel <> ".*"

458− <+> renderTableExpression relations

459

626

460-- | `values` computes a row value or set of row values

627-- | `values` computes a row value or set of row values

461-- specified by value expressions. It is most commonly used

628-- specified by value expressions. It is most commonly used

@@ -463,16 +630,16 @@ selectDistinctDotStar rel relations = UnsafeQuery $

463-- but it can be used on its own.

630-- but it can be used on its own.

464--

631--

465-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]

632-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]

466−-- >>> let query = values (1 `As` #a :* "one" `As` #b :* Nil) [] :: Query '[] '[] Row

633+-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query outer commons schemas '[] Row

467-- >>> printSQL query

634-- >>> printSQL query

468-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")

635-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")

469values

636values

470 :: SListI cols

637 :: SListI cols

471− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

638+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

472− -> [NP (Aliased (Expression schema '[] 'Ungrouped params)) cols]

639+ -> [NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols]

473 -- ^ When more than one row is specified, all the rows must

640 -- ^ When more than one row is specified, all the rows must

474 -- must have the same number of elements

641 -- must have the same number of elements

475− -> Query schema params cols

642+ -> Query outer commons schemas params cols

476values rw rws = UnsafeQuery $ "SELECT * FROM"

643values rw rws = UnsafeQuery $ "SELECT * FROM"

477 <+> parenthesized (

644 <+> parenthesized (

478 "VALUES"

645 "VALUES"

@@ -483,17 +650,17 @@ values rw rws = UnsafeQuery $ "SELECT * FROM"

483 <+> parenthesized (renderCommaSeparated renderAliasPart rw)

650 <+> parenthesized (renderCommaSeparated renderAliasPart rw)

484 where

651 where

485 renderAliasPart, renderValuePart

652 renderAliasPart, renderValuePart

486− :: Aliased (Expression schema '[] 'Ungrouped params) ty -> ByteString

653+ :: Aliased (Expression outer commons 'Ungrouped schemas params '[] ) ty -> ByteString

487− renderAliasPart (_ `As` name) = renderAlias name

654+ renderAliasPart (_ `As` name) = renderSQL name

488− renderValuePart (value `As` _) = renderExpression value

655+ renderValuePart (value `As` _) = renderSQL value

489

656

490-- | `values_` computes a row value or set of row values

657-- | `values_` computes a row value or set of row values

491-- specified by value expressions.

658-- specified by value expressions.

492values_

659values_

493 :: SListI cols

660 :: SListI cols

494− => NP (Aliased (Expression schema '[] 'Ungrouped params)) cols

661+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

495 -- ^ one row of values

662 -- ^ one row of values

496− -> Query schema params cols

663+ -> Query outer commons schemas params cols

497values_ rw = values rw []

664values_ rw = values rw []

498

665

499{-----------------------------------------

666{-----------------------------------------

@@ -507,15 +674,17 @@ Table Expressions

507-- to a table on disk, a so-called base table, but more complex expressions

674-- to a table on disk, a so-called base table, but more complex expressions

508-- can be used to modify or combine base tables in various ways.

675-- can be used to modify or combine base tables in various ways.

509data TableExpression

676data TableExpression

510− (schema :: SchemaType)

677+ (outer :: FromType)

678+ (commons :: FromType)

679+ (grp :: Grouping)

680+ (schemas :: SchemasType)

511 (params :: [NullityType])

681 (params :: [NullityType])

512− (relations :: RelationsType)

682+ (from :: FromType)

513− (grouping :: Grouping)

514 = TableExpression

683 = TableExpression

515− { fromClause :: FromClause schema params relations

684+ { fromClause :: FromClause outer commons schemas params from

516 -- ^ A table reference that can be a table name, or a derived table such

685 -- ^ A table reference that can be a table name, or a derived table such

517 -- as a subquery, a @JOIN@ construct, or complex combinations of these.

686 -- as a subquery, a @JOIN@ construct, or complex combinations of these.

518− , whereClause :: [Condition schema relations 'Ungrouped params]

687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]

519 -- ^ optional search coditions, combined with `.&&`. After the processing

688 -- ^ optional search coditions, combined with `.&&`. After the processing

520 -- of the `fromClause` is done, each row of the derived virtual table

689 -- of the `fromClause` is done, each row of the derived virtual table

521 -- is checked against the search condition. If the result of the

690 -- is checked against the search condition. If the result of the

@@ -524,20 +693,20 @@ data TableExpression

524 -- at least one column of the table generated in the `fromClause`;

693 -- at least one column of the table generated in the `fromClause`;

525 -- this is not required, but otherwise the WHERE clause will

694 -- this is not required, but otherwise the WHERE clause will

526 -- be fairly useless.

695 -- be fairly useless.

527− , groupByClause :: GroupByClause relations grouping

696+ , groupByClause :: GroupByClause grp from

528 -- ^ The `groupByClause` is used to group together those rows in a table

697 -- ^ The `groupByClause` is used to group together those rows in a table

529 -- that have the same values in all the columns listed. The order in which

698 -- that have the same values in all the columns listed. The order in which

530 -- the columns are listed does not matter. The effect is to combine each

699 -- the columns are listed does not matter. The effect is to combine each

531 -- set of rows having common values into one group row that represents all

700 -- set of rows having common values into one group row that represents all

532 -- rows in the group. This is done to eliminate redundancy in the output

701 -- rows in the group. This is done to eliminate redundancy in the output

533 -- and/or compute aggregates that apply to these groups.

702 -- and/or compute aggregates that apply to these groups.

534− , havingClause :: HavingClause schema relations grouping params

703+ , havingClause :: HavingClause outer commons grp schemas params from

535 -- ^ If a table has been grouped using `groupBy`, but only certain groups

704 -- ^ If a table has been grouped using `groupBy`, but only certain groups

536 -- are of interest, the `havingClause` can be used, much like a

705 -- are of interest, the `havingClause` can be used, much like a

537 -- `whereClause`, to eliminate groups from the result. Expressions in the

706 -- `whereClause`, to eliminate groups from the result. Expressions in the

538 -- `havingClause` can refer both to grouped expressions and to ungrouped

707 -- `havingClause` can refer both to grouped expressions and to ungrouped

539 -- expressions (which necessarily involve an aggregate function).

708 -- expressions (which necessarily involve an aggregate function).

540− , orderByClause :: [SortExpression schema relations grouping params]

709+ , orderByClause :: [SortExpression outer commons grp schemas params from]

541 -- ^ The `orderByClause` is for optional sorting. When more than one

710 -- ^ The `orderByClause` is for optional sorting. When more than one

542 -- `SortExpression` is specified, the later (right) values are used to sort

711 -- `SortExpression` is specified, the later (right) values are used to sort

543 -- rows that are equal according to the earlier (left) values.

712 -- rows that are equal according to the earlier (left) values.

@@ -547,72 +716,69 @@ data TableExpression

547 -- will be returned (but possibly fewer, if the query itself yields

716 -- will be returned (but possibly fewer, if the query itself yields

548 -- fewer rows).

717 -- fewer rows).

549 , offsetClause :: [Word64]

718 , offsetClause :: [Word64]

550− -- ^ The `offsetClause` is combined with `+` to give an offset count

719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count

551 -- if nonempty. The offset count says to skip that many rows before

720 -- if nonempty. The offset count says to skip that many rows before

552 -- beginning to return rows. The rows are skipped before the limit count

721 -- beginning to return rows. The rows are skipped before the limit count

553 -- is applied.

722 -- is applied.

554− }

723+ } deriving (GHC.Generic)

555

724

556-- | Render a `TableExpression`

725-- | Render a `TableExpression`

557−renderTableExpression

726+instance RenderSQL (TableExpression outer commons grp schemas params from) where

558− :: TableExpression schema params relations grouping

727+ renderSQL

559− -> ByteString

560−renderTableExpression

561− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

728+ (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

562− [ "FROM ", renderFromClause frm'

729+ [ "FROM ", renderSQL frm'

563− , renderWheres whs'

730+ , renderWheres whs'

564− , renderGroupByClause grps'

731+ , renderSQL grps'

565− , renderHavingClause hvs'

732+ , renderSQL hvs'

566− , renderOrderByClause srts'

733+ , renderOrderByClause srts'

567− , renderLimits lims'

734+ , renderLimits lims'

568− , renderOffsets offs'

735+ , renderOffsets offs' ]

569− ]

570− where

736+ where

571− renderWheres = \case

737+ renderWheres = \case

572− [] -> ""

738+ [] -> ""

573− wh:[] -> " WHERE" <+> renderExpression wh

739+ wh:[] -> " WHERE" <+> renderSQL wh

574− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

740+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

575− renderOrderByClause = \case

741+ renderOrderByClause = \case

576− [] -> ""

742+ [] -> ""

577− srts -> " ORDER BY"

743+ srts -> " ORDER BY"

578− <+> commaSeparated (renderSortExpression <$> srts)

744+ <+> commaSeparated (renderSQL <$> srts)

579− renderLimits = \case

745+ renderLimits = \case

580− [] -> ""

746+ [] -> ""

581− lims -> " LIMIT" <+> fromString (show (minimum lims))

747+ lims -> " LIMIT" <+> fromString (show (minimum lims))

582− renderOffsets = \case

748+ renderOffsets = \case

583− [] -> ""

749+ [] -> ""

584− offs -> " OFFSET" <+> fromString (show (sum offs))

750+ offs -> " OFFSET" <+> fromString (show (sum offs))

585

751

586-- | A `from` generates a `TableExpression` from a table reference that can be

752-- | A `from` generates a `TableExpression` from a table reference that can be

587-- a table name, or a derived table such as a subquery, a JOIN construct,

753-- a table name, or a derived table such as a subquery, a JOIN construct,

588-- or complex combinations of these. A `from` may be transformed by `where_`,

754-- or complex combinations of these. A `from` may be transformed by `where_`,

589−-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

590-- to match the left-to-right sequencing of their placement in SQL.

756-- to match the left-to-right sequencing of their placement in SQL.

591from

757from

592− :: FromClause schema params relations -- ^ table reference

758+ :: FromClause outer commons schemas params from -- ^ table reference

593− -> TableExpression schema params relations 'Ungrouped

759+ -> TableExpression outer commons 'Ungrouped schemas params from

594−from rels = TableExpression rels [] NoGroups NoHaving [] [] []

760+from tab = TableExpression tab [] noGroups NoHaving [] [] []

595

761

596-- | A `where_` is an endomorphism of `TableExpression`s which adds a

762-- | A `where_` is an endomorphism of `TableExpression`s which adds a

597-- search condition to the `whereClause`.

763-- search condition to the `whereClause`.

598where_

764where_

599− :: Condition schema relations 'Ungrouped params -- ^ filtering condition

765+ :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition

600− -> TableExpression schema params relations grouping

766+ -> TableExpression outer commons grp schemas params from

601− -> TableExpression schema params relations grouping

767+ -> TableExpression outer commons grp schemas params from

602where_ wh rels = rels {whereClause = wh : whereClause rels}

768where_ wh rels = rels {whereClause = wh : whereClause rels}

603

769

604−-- | A `group` is a transformation of `TableExpression`s which switches

770+-- | A `groupBy` is a transformation of `TableExpression`s which switches

605−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform

771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform

606-- a "grand total" aggregation query.

772-- a "grand total" aggregation query.

607−group

773+groupBy

608 :: SListI bys

774 :: SListI bys

609− => NP (By relations) bys -- ^ grouped columns

775+ => NP (By from) bys -- ^ grouped columns

610− -> TableExpression schema params relations 'Ungrouped

776+ -> TableExpression outer commons 'Ungrouped schemas params from

611− -> TableExpression schema params relations ('Grouped bys)

777+ -> TableExpression outer commons ('Grouped bys) schemas params from

612−group bys rels = TableExpression

778+groupBy bys rels = TableExpression

613 { fromClause = fromClause rels

779 { fromClause = fromClause rels

614 , whereClause = whereClause rels

780 , whereClause = whereClause rels

615− , groupByClause = Group bys

781+ , groupByClause = group bys

616 , havingClause = Having []

782 , havingClause = Having []

617 , orderByClause = []

783 , orderByClause = []

618 , limitClause = limitClause rels

784 , limitClause = limitClause rels

@@ -622,34 +788,29 @@ group bys rels = TableExpression

622-- | A `having` is an endomorphism of `TableExpression`s which adds a

788-- | A `having` is an endomorphism of `TableExpression`s which adds a

623-- search condition to the `havingClause`.

789-- search condition to the `havingClause`.

624having

790having

625− :: Condition schema relations ('Grouped bys) params -- ^ having condition

791+ :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition

626− -> TableExpression schema params relations ('Grouped bys)

792+ -> TableExpression outer commons ('Grouped bys) schemas params from

627− -> TableExpression schema params relations ('Grouped bys)

793+ -> TableExpression outer commons ('Grouped bys) schemas params from

628having hv rels = rels

794having hv rels = rels

629 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

630

796

631−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an

797+instance OrderBy TableExpression where

632−-- ordering to the right of the `orderByClause`.

633−orderBy

634− :: [SortExpression schema relations grouping params] -- ^ sort expressions

635− -> TableExpression schema params relations grouping

636− -> TableExpression schema params relations grouping

637−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

638

799

639-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

800-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

640-- `limitClause`.

801-- `limitClause`.

641limit

802limit

642 :: Word64 -- ^ limit parameter

803 :: Word64 -- ^ limit parameter

643− -> TableExpression schema params relations grouping

804+ -> TableExpression outer commons grp schemas params from

644− -> TableExpression schema params relations grouping

805+ -> TableExpression outer commons grp schemas params from

645limit lim rels = rels {limitClause = lim : limitClause rels}

806limit lim rels = rels {limitClause = lim : limitClause rels}

646

807

647-- | An `offset` is an endomorphism of `TableExpression`s which adds to the

808-- | An `offset` is an endomorphism of `TableExpression`s which adds to the

648-- `offsetClause`.

809-- `offsetClause`.

649offset

810offset

650 :: Word64 -- ^ offset parameter

811 :: Word64 -- ^ offset parameter

651− -> TableExpression schema params relations grouping

812+ -> TableExpression outer commons grp schemas params from

652− -> TableExpression schema params relations grouping

813+ -> TableExpression outer commons grp schemas params from

653offset off rels = rels {offsetClause = off : offsetClause rels}

814offset off rels = rels {offsetClause = off : offsetClause rels}

654

815

655{-----------------------------------------

816{-----------------------------------------

@@ -660,61 +821,76 @@ FROM clauses

660A `FromClause` can be a table name, or a derived table such

821A `FromClause` can be a table name, or a derived table such

661as a subquery, a @JOIN@ construct, or complex combinations of these.

822as a subquery, a @JOIN@ construct, or complex combinations of these.

662-}

823-}

663−newtype FromClause schema params relations

824+newtype FromClause outer commons schemas params from

664 = UnsafeFromClause { renderFromClause :: ByteString }

825 = UnsafeFromClause { renderFromClause :: ByteString }

665 deriving (GHC.Generic,Show,Eq,Ord,NFData)

826 deriving (GHC.Generic,Show,Eq,Ord,NFData)

827+instance RenderSQL (FromClause outer commons schemas params from) where

828+ renderSQL = renderFromClause

666

829

667−-- | A real `table` is a table from the schema.

830+-- | A real `table` is a table from the database.

668table

831table

669− :: Has tab schema ('Table table)

832+ :: (Has sch schemas schema, Has tab schema ('Table table))

670− => Aliased Alias (alias ::: tab)

833+ => Aliased (QualifiedAlias sch) (alias ::: tab)

671− -> FromClause schema params '[alias ::: TableToRelation table]

834+ -> FromClause outer commons schemas params '[alias ::: TableToRow table]

672table (tab `As` alias) = UnsafeFromClause $

835table (tab `As` alias) = UnsafeFromClause $

673− renderAlias tab <+> "AS" <+> renderAlias alias

836+ renderSQL tab <+> "AS" <+> renderSQL alias

674

837

675-- | `subquery` derives a table from a `Query`.

838-- | `subquery` derives a table from a `Query`.

676subquery

839subquery

677− :: Aliased (Query schema params) rel

840+ :: Aliased (Query outer commons schemas params) query

678− -> FromClause schema params '[rel]

841+ -> FromClause outer commons schemas params '[query]

679−subquery = UnsafeFromClause . renderAliasedAs (parenthesized . renderQuery)

842+subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)

680

843

681-- | `view` derives a table from a `View`.

844-- | `view` derives a table from a `View`.

682view

845view

683− :: Has view schema ('View rel)

846+ :: (Has sch schemas schema, Has vw schema ('View view))

684− => Aliased Alias (alias ::: view)

847+ => Aliased (QualifiedAlias sch) (alias ::: vw)

685− -> FromClause schema params '[alias ::: rel]

848+ -> FromClause outer commons schemas params '[alias ::: view]

686view (vw `As` alias) = UnsafeFromClause $

849view (vw `As` alias) = UnsafeFromClause $

687− 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

688

863

864+{- |

689−{- | @left & crossJoin right@. For every possible combination of rows from

865+@left & crossJoin right@. For every possible combination of rows from

690− @left@ and @right@ (i.e., a Cartesian product), the joined table will contain

866+@left@ and @right@ (i.e., a Cartesian product), the joined table will contain

691− a row consisting of all columns in @left@ followed by all columns in @right@.

867+a row consisting of all columns in @left@ followed by all columns in @right@.

692− If the tables have @n@ and @m@ rows respectively, the joined table will

868+If the tables have @n@ and @m@ rows respectively, the joined table will

693− have @n * m@ rows.

869+have @n * m@ rows.

694-}

870-}

695crossJoin

871crossJoin

696− :: FromClause schema params right

872+ :: FromClause outer commons schemas params right

697 -- ^ right

873 -- ^ right

698− -> FromClause schema params left

874+ -> FromClause outer commons schemas params left

699 -- ^ left

875 -- ^ left

700− -> FromClause schema params (Join left right)

876+ -> FromClause outer commons schemas params (Join left right)

701crossJoin right left = UnsafeFromClause $

877crossJoin right left = UnsafeFromClause $

702− renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right

878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right

703

879

704{- | @left & innerJoin right on@. The joined table is filtered by

880{- | @left & innerJoin right on@. The joined table is filtered by

705the @on@ condition.

881the @on@ condition.

706-}

882-}

707innerJoin

883innerJoin

708− :: FromClause schema params right

884+ :: FromClause outer commons schemas params right

709 -- ^ right

885 -- ^ right

710− -> Condition schema (Join left right) 'Ungrouped params

886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

711 -- ^ @on@ condition

887 -- ^ @on@ condition

712− -> FromClause schema params left

888+ -> FromClause outer commons schemas params left

713 -- ^ left

889 -- ^ left

714− -> FromClause schema params (Join left right)

890+ -> FromClause outer commons schemas params (Join left right)

715innerJoin right on left = UnsafeFromClause $

891innerJoin right on left = UnsafeFromClause $

716− renderFromClause left <+> "INNER JOIN" <+> renderFromClause right

892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right

717− <+> "ON" <+> renderExpression on

893+ <+> "ON" <+> renderSQL on

718

894

719{- | @left & leftOuterJoin right on@. First, an inner join is performed.

895{- | @left & leftOuterJoin right on@. First, an inner join is performed.

720 Then, for each row in @left@ that does not satisfy the @on@ condition with

896 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -722,16 +898,16 @@ innerJoin right on left = UnsafeFromClause $

722 Thus, the joined table always has at least one row for each row in @left@.

898 Thus, the joined table always has at least one row for each row in @left@.

723-}

899-}

724leftOuterJoin

900leftOuterJoin

725− :: FromClause schema params right

901+ :: FromClause outer commons schemas params right

726 -- ^ right

902 -- ^ right

727− -> Condition schema (Join left right) 'Ungrouped params

903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

728 -- ^ @on@ condition

904 -- ^ @on@ condition

729− -> FromClause schema params left

905+ -> FromClause outer commons schemas params left

730 -- ^ left

906 -- ^ left

731− -> FromClause schema params (Join left (NullifyRelations right))

907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))

732leftOuterJoin right on left = UnsafeFromClause $

908leftOuterJoin right on left = UnsafeFromClause $

733− renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right

909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right

734− <+> "ON" <+> renderExpression on

910+ <+> "ON" <+> renderSQL on

735

911

736{- | @left & rightOuterJoin right on@. First, an inner join is performed.

912{- | @left & rightOuterJoin right on@. First, an inner join is performed.

737 Then, for each row in @right@ that does not satisfy the @on@ condition with

913 Then, for each row in @right@ that does not satisfy the @on@ condition with

@@ -740,16 +916,16 @@ leftOuterJoin right on left = UnsafeFromClause $

740 have a row for each row in @right@.

916 have a row for each row in @right@.

741-}

917-}

742rightOuterJoin

918rightOuterJoin

743− :: FromClause schema params right

919+ :: FromClause outer commons schemas params right

744 -- ^ right

920 -- ^ right

745− -> Condition schema (Join left right) 'Ungrouped params

921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

746 -- ^ @on@ condition

922 -- ^ @on@ condition

747− -> FromClause schema params left

923+ -> FromClause outer commons schemas params left

748 -- ^ left

924 -- ^ left

749− -> FromClause schema params (Join (NullifyRelations left) right)

925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)

750rightOuterJoin right on left = UnsafeFromClause $

926rightOuterJoin right on left = UnsafeFromClause $

751− renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right

927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right

752− <+> "ON" <+> renderExpression on

928+ <+> "ON" <+> renderSQL on

753

929

754{- | @left & fullOuterJoin right on@. First, an inner join is performed.

930{- | @left & fullOuterJoin right on@. First, an inner join is performed.

755 Then, for each row in @left@ that does not satisfy the @on@ condition with

931 Then, for each row in @left@ that does not satisfy the @on@ condition with

@@ -759,47 +935,56 @@ rightOuterJoin right on left = UnsafeFromClause $

759 is added.

935 is added.

760-}

936-}

761fullOuterJoin

937fullOuterJoin

762− :: FromClause schema params right

938+ :: FromClause outer commons schemas params right

763 -- ^ right

939 -- ^ right

764− -> Condition schema (Join left right) 'Ungrouped params

940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

765 -- ^ @on@ condition

941 -- ^ @on@ condition

766− -> FromClause schema params left

942+ -> FromClause outer commons schemas params left

767 -- ^ left

943 -- ^ left

768− -> FromClause schema params

944+ -> FromClause outer commons schemas params

769− (Join (NullifyRelations left) (NullifyRelations right))

945+ (Join (NullifyFrom left) (NullifyFrom right))

770fullOuterJoin right on left = UnsafeFromClause $

946fullOuterJoin right on left = UnsafeFromClause $

771− renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right

947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right

772− <+> "ON" <+> renderExpression on

948+ <+> "ON" <+> renderSQL on

773

949

774{-----------------------------------------

950{-----------------------------------------

775Grouping

951Grouping

776-----------------------------------------}

952-----------------------------------------}

777

953

778−-- | `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

779-- used to group together those rows in a table that have the same values

955-- used to group together those rows in a table that have the same values

780-- in all the columns listed. @By \#col@ will reference an unambiguous

956-- in all the columns listed. @By \#col@ will reference an unambiguous

781-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

782-- qualified column @tab.col@.

958-- qualified column @tab.col@.

783data By

959data By

784− (relations :: RelationsType)

960+ (from :: FromType)

785 (by :: (Symbol,Symbol)) where

961 (by :: (Symbol,Symbol)) where

786− By

962+ By1

787− :: (HasUnique relation relations columns, Has column columns ty)

963+ :: (HasUnique table from columns, Has column columns ty)

788 => Alias column

964 => Alias column

789− -> By relations '(relation, column)

965+ -> By from '(table, column)

790 By2

966 By2

791− :: (Has relation relations columns, Has column columns ty)

967+ :: (Has table from columns, Has column columns ty)

968+ => Alias table

792− => (Alias relation, Alias column)

969+ -> Alias column

793− -> By relations '(relation, column)

970+ -> By from '(table, column)

794−deriving instance Show (By relations by)

971+deriving instance Show (By from by)

795−deriving instance Eq (By relations by)

972+deriving instance Eq (By from by)

796−deriving instance Ord (By relations by)

973+deriving instance Ord (By from by)

797−

974+instance RenderSQL (By from by) where

798−-- | Renders a `By`.

975+ renderSQL = \case

799−renderBy :: By relations by -> ByteString

800−renderBy = \case

801− By column -> renderAlias column

976+ By1 column -> renderSQL column

802− By2 (rel, column) -> renderAlias rel <> "." <> renderAlias column

977+ By2 rel column -> renderSQL rel <> "." <> renderSQL column

978+

979+instance (HasUnique rel rels cols, Has col cols ty, by ~ '(rel, col))

980+ => IsLabel col (By rels by) where fromLabel = By1 fromLabel

981+instance (HasUnique rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

982+ => IsLabel col (NP (By rels) bys) where fromLabel = By1 fromLabel :* Nil

983+instance (Has rel rels cols, Has col cols ty, by ~ '(rel, col))

984+ => IsQualified rel col (By rels by) where (!) = By2

985+instance (Has rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

986+ => IsQualified rel col (NP (By rels) bys) where

987+ rel ! col = By2 rel col :* Nil

803

988

804-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

805-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

@@ -807,82 +992,107 @@ renderBy = \case

807-- done on @NoGroups@ while all output `Expression`s must be aggregated

992-- done on @NoGroups@ while all output `Expression`s must be aggregated

808-- in @Group Nil@. In general, all output `Expression`s in the

993-- in @Group Nil@. In general, all output `Expression`s in the

809-- complement of @bys@ must be aggregated in @Group bys@.

994-- complement of @bys@ must be aggregated in @Group bys@.

995+newtype GroupByClause grp from = UnsafeGroupByClause

996+ { renderGroupByClause :: ByteString }

997+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

810−data GroupByClause relations grouping where

998+instance RenderSQL (GroupByClause grp from) where

999+ renderSQL = renderGroupByClause

811− NoGroups :: GroupByClause relations 'Ungrouped

1000+noGroups :: GroupByClause 'Ungrouped from

812− Group

1001+noGroups = UnsafeGroupByClause ""

1002+group

813− :: SListI bys

1003+ :: SListI bys

814− => NP (By relations) bys

1004+ => NP (By from) bys

815− -> GroupByClause relations ('Grouped bys)

1005+ -> GroupByClause ('Grouped bys) from

816−

1006+group bys = UnsafeGroupByClause $ case bys of

817−-- | Renders a `GroupByClause`.

818−renderGroupByClause :: GroupByClause relations grouping -> ByteString

819−renderGroupByClause = \case

820− NoGroups -> ""

821− Group Nil -> ""

1007+ Nil -> ""

822− Group bys -> " GROUP BY" <+> renderCommaSeparated renderBy bys

1008+ bys' -> " GROUP BY" <+> renderCommaSeparated renderSQL bys'

823

1009

824-- | A `HavingClause` is used to eliminate groups that are not of interest.

1010-- | A `HavingClause` is used to eliminate groups that are not of interest.

825-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

1011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

826-- `TableExpression` must use `Having` whose conditions are combined with

1012-- `TableExpression` must use `Having` whose conditions are combined with

827-- `.&&`.

1013-- `.&&`.

828−data HavingClause schema relations grouping params where

1014+data HavingClause outer commons grp schemas params from where

829− NoHaving :: HavingClause schema relations 'Ungrouped params

1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from

830 Having

1016 Having

831− :: [Condition schema relations ('Grouped bys) params]

1017+ :: [Condition outer commons ('Grouped bys) schemas params from]

832− -> HavingClause schema relations ('Grouped bys) params

1018+ -> HavingClause outer commons ('Grouped bys) schemas params from

833−deriving instance Show (HavingClause schema relations grouping params)

1019+deriving instance Show (HavingClause outer commons grp schemas params from)

834−deriving instance Eq (HavingClause schema relations grouping params)

1020+deriving instance Eq (HavingClause outer commons grp schemas params from)

835−deriving instance Ord (HavingClause schema relations grouping params)

1021+deriving instance Ord (HavingClause outer commons grp schemas params from)

836

1022

837-- | Render a `HavingClause`.

1023-- | Render a `HavingClause`.

838−renderHavingClause :: HavingClause schema relations grouping params -> ByteString

1024+instance RenderSQL (HavingClause outer commons grp schemas params from) where

839−renderHavingClause = \case

1025+ renderSQL = \case

840− NoHaving -> ""

1026+ NoHaving -> ""

841− Having [] -> ""

1027+ Having [] -> ""

842− Having conditions ->

1028+ Having conditions ->

843− " HAVING" <+> commaSeparated (renderExpression <$> conditions)

1029+ " HAVING" <+> commaSeparated (renderSQL <$> conditions)

844−

1030+

845−{-----------------------------------------

1031+-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.

846−Sorting

1032+data CommonTableExpression statement

847−-----------------------------------------}

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

848

1074

849−-- | `SortExpression`s are used by `sortBy` to optionally sort the results

1075+{- |

850−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result

1076+>>> import Data.Monoid (Sum (..))

851−-- column to ascending or descending. Ascending order puts smaller values

1077+>>> import Data.Int (Int64)

852−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,

1078+>>> :{

853−-- descending order is determined with the `.>` operator. `AscNullsFirst`,

1079+ let

854−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

1080+ query :: Query_ schema () (Sum Int64)

855−-- determine whether nulls appear before or after non-null values in the sort

1081+ query = withRecursive

856−-- ordering of a `Null` result column.

1082+ ( values_ ((1 & astype int) `as` #n)

857−data SortExpression schema relations grouping params where

1083+ `unionAll`

858− Asc

1084+ select_ ((#n + 1) `as` #n)

859− :: Expression schema relations grouping params ('NotNull ty)

1085+ (from (common #t) & where_ (#n .< 100)) `as` #t )

860− -> SortExpression schema relations grouping params

1086+ ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))

861− Desc

1087+ in printSQL query

862− :: Expression schema relations grouping params ('NotNull ty)

1088+:}

863− -> SortExpression schema relations grouping params

1089+WITH RECURSIVE "t" AS ((SELECT * FROM (VALUES ((1 :: int))) AS t ("n")) UNION ALL (SELECT ("n" + 1) AS "n" FROM "t" AS "t" WHERE ("n" < 100))) SELECT COALESCE(sum(ALL "n"), 0) AS "getSum" FROM "t" AS "t"

864− AscNullsFirst

1090+-}

865− :: Expression schema relations grouping params ('Null ty)

1091+withRecursive

866− -> SortExpression schema relations grouping params

1092+ :: Aliased (Query outer (recursive ': commons) schemas params) recursive

867− AscNullsLast

1093+ -> Query outer (recursive ': commons) schemas params row

868− :: Expression schema relations grouping params ('Null ty)

1094+ -> Query outer commons schemas params row

869− -> SortExpression schema relations grouping params

1095+withRecursive (recursive `As` cte) query = UnsafeQuery $

870− DescNullsFirst

1096+ "WITH RECURSIVE" <+> renderSQL cte

871− :: Expression schema relations grouping params ('Null ty)

1097+ <+> "AS" <+> parenthesized (renderSQL recursive)

872− -> SortExpression schema relations grouping params

1098+ <+> renderSQL query

873− DescNullsLast

874− :: Expression schema relations grouping params ('Null ty)

875− -> SortExpression schema relations grouping params

876−deriving instance Show (SortExpression schema relations grouping params)

877−

878−-- | Render a `SortExpression`.

879−renderSortExpression :: SortExpression schema relations grouping params -> ByteString

880−renderSortExpression = \case

881− Asc expression -> renderExpression expression <+> "ASC"

882− Desc expression -> renderExpression expression <+> "DESC"

883− AscNullsFirst expression -> renderExpression expression

884− <+> "ASC NULLS FIRST"

885− DescNullsFirst expression -> renderExpression expression

886− <+> "DESC NULLS FIRST"

887− AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"

888− DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"

squeal-postgresql/src/Squeal/PostgreSQL/Render.hs+66−13

@@ -9,35 +9,48 @@ Rendering helper functions.

9-}

11{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

12− FlexibleContexts

14+ , FlexibleContexts

15+ , LambdaCase

13 , MagicHash

16 , MagicHash

14 , OverloadedStrings

17 , OverloadedStrings

15 , PolyKinds

18 , PolyKinds

16 , RankNTypes

19 , RankNTypes

17 , ScopedTypeVariables

20 , ScopedTypeVariables

21+ , TypeApplications

18#-}

22#-}

20module Squeal.PostgreSQL.Render

24module Squeal.PostgreSQL.Render

21 ( -- * Render

25 ( -- * Render

26+ RenderSQL (..)

27+ , printSQL

28+ , escape

22− parenthesized

29+ , parenthesized

30+ , bracketed

23 , (<+>)

31 , (<+>)

24 , commaSeparated

32 , commaSeparated

25 , doubleQuoted

33 , doubleQuoted

34+ , singleQuotedText

35+ , singleQuotedUtf8

26 , renderCommaSeparated

36 , renderCommaSeparated

37+ , renderCommaSeparatedConstraint

27 , renderCommaSeparatedMaybe

38 , renderCommaSeparatedMaybe

28 , renderNat

39 , renderNat

29− , RenderSQL (..)

40+ , renderSymbol

30− , printSQL

31 ) where

41 ) where

33−import Control.Monad.Base

43+import Control.Monad.IO.Class (MonadIO (..))

34import Data.ByteString (ByteString)

44import Data.ByteString (ByteString)

35−import Data.Maybe

45+import Data.Maybe (catMaybes)

36import Data.Monoid ((<>))

46import Data.Monoid ((<>))

47+import Data.Text (Text)

37import Generics.SOP

48import Generics.SOP

38import GHC.Exts

49import GHC.Exts

39−import GHC.TypeLits

50+import GHC.TypeLits hiding (Text)

52+import qualified Data.Text as Text

53+import qualified Data.Text.Encoding as Text

41import qualified Data.ByteString as ByteString

54import qualified Data.ByteString as ByteString

42import qualified Data.ByteString.Char8 as Char8

55import qualified Data.ByteString.Char8 as Char8

@@ -45,8 +58,13 @@ import qualified Data.ByteString.Char8 as Char8

45parenthesized :: ByteString -> ByteString

58parenthesized :: ByteString -> ByteString

46parenthesized str = "(" <> str <> ")"

59parenthesized str = "(" <> str <> ")"

61+-- | Square bracket a `ByteString`

62+bracketed :: ByteString -> ByteString

63+bracketed str = "[" <> str <> "]"

64+

48-- | Concatenate two `ByteString`s with a space between.

65-- | Concatenate two `ByteString`s with a space between.

49(<+>) :: ByteString -> ByteString -> ByteString

66(<+>) :: ByteString -> ByteString -> ByteString

67+infixr 7 <+>

50str1 <+> str2 = str1 <> " " <> str2

68str1 <+> str2 = str1 <> " " <> str2

52-- | Comma separate a list of `ByteString`s.

70-- | Comma separate a list of `ByteString`s.

@@ -57,6 +75,15 @@ commaSeparated = ByteString.intercalate ", "

57doubleQuoted :: ByteString -> ByteString

75doubleQuoted :: ByteString -> ByteString

58doubleQuoted str = "\"" <> str <> "\""

76doubleQuoted str = "\"" <> str <> "\""

78+-- | Add single quotes around a `Text` and escape single quotes within it.

79+singleQuotedText :: Text -> ByteString

80+singleQuotedText str =

81+ "'" <> Text.encodeUtf8 (Text.replace "'" "''" str) <> "'"

82+

83+-- | Add single quotes around a `ByteString` and escape single quotes within it.

84+singleQuotedUtf8 :: ByteString -> ByteString

85+singleQuotedUtf8 = singleQuotedText . Text.decodeUtf8

86+

60-- | Comma separate the renderings of a heterogeneous list.

87-- | Comma separate the renderings of a heterogeneous list.

61renderCommaSeparated

88renderCommaSeparated

62 :: SListI xs

89 :: SListI xs

@@ -67,6 +94,16 @@ renderCommaSeparated render

67 . hcollapse

94 . hcollapse

68 . hmap (K . render)

95 . hmap (K . render)

97+-- | Comma separate the renderings of a heterogeneous list.

98+renderCommaSeparatedConstraint

99+ :: forall c xs expression. (All c xs, SListI xs)

100+ => (forall x. c x => expression x -> ByteString)

101+ -> NP expression xs -> ByteString

102+renderCommaSeparatedConstraint render

103+ = commaSeparated

104+ . hcollapse

105+ . hcmap (Proxy @c) (K . render)

106+

70-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

107-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

71-- `Nothing`s.

108-- `Nothing`s.

72renderCommaSeparatedMaybe

109renderCommaSeparatedMaybe

@@ -80,13 +117,29 @@ renderCommaSeparatedMaybe render

80 . hmap (K . render)

117 . hmap (K . render)

118

82-- | Render a promoted `Nat`.

119-- | Render a promoted `Nat`.

83−renderNat :: KnownNat n => proxy n -> ByteString

120+renderNat :: forall n. KnownNat n => ByteString

84−renderNat (_ :: proxy n) = fromString (show (natVal' (proxy# :: Proxy# n)))

121+renderNat = fromString (show (natVal' (proxy# :: Proxy# n)))

122+

123+-- | Render a promoted `Symbol`.

124+renderSymbol :: forall s. KnownSymbol s => ByteString

125+renderSymbol = fromString (symbolVal' (proxy# :: Proxy# s))

126

86-- | A class for rendering SQL

127-- | A class for rendering SQL

87−class RenderSQL sql where

128+class RenderSQL sql where renderSQL :: sql -> ByteString

88− renderSQL :: sql -> ByteString

129

90-- | Print SQL.

130-- | Print SQL.

91−printSQL :: (RenderSQL sql, MonadBase IO io) => sql -> io ()

131+printSQL :: (RenderSQL sql, MonadIO io) => sql -> io ()

92−printSQL = liftBase . Char8.putStrLn . renderSQL

132+printSQL = liftIO . Char8.putStrLn . renderSQL

133+

134+-- | `escape` a character to prevent injection

135+escape :: Char -> String

136+escape = \case

137+ '\NUL' -> "\\0"

138+ '\'' -> "''"

139+ '"' -> "\\\""

140+ '\b' -> "\\b"

141+ '\n' -> "\\n"

142+ '\r' -> "\\r"

143+ '\t' -> "\\t"

144+ '\\' -> "\\\\"

145+ c -> [c]

squeal-postgresql/src/Squeal/PostgreSQL/Schema.hs+318−586

@@ -1,16 +1,15 @@

1{-|

2Module: Squeal.PostgreSQL.Schema

3Description: Embedding of PostgreSQL type and alias system

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

5Maintainer: eitan@morphism.tech

6Stability: 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,

9tables, schema, constraints, aliases, enumerated labels, and groupings.

10It also defines useful type families to operate on these. Finally,

11it defines an embedding of Haskell types into Postgres types.

12-}

13−

14{-# LANGUAGE

13{-# LANGUAGE

15 AllowAmbiguousTypes

14 AllowAmbiguousTypes

16 , ConstraintKinds

15 , ConstraintKinds

@@ -20,7 +19,9 @@ it defines an embedding of Haskell types into Postgres types.

20 , FlexibleInstances

19 , FlexibleInstances

21 , FunctionalDependencies

20 , FunctionalDependencies

22 , GADTs

21 , GADTs

22+ , LambdaCase

23 , OverloadedStrings

24+ , QuantifiedConstraints

24 , RankNTypes

25 , RankNTypes

25 , ScopedTypeVariables

26 , ScopedTypeVariables

26 , StandaloneDeriving

27 , StandaloneDeriving

@@ -33,125 +34,85 @@ it defines an embedding of Haskell types into Postgres types.

33#-}

34#-}

35module Squeal.PostgreSQL.Schema

36module Squeal.PostgreSQL.Schema

36− ( -- * Types

37+ ( -- * Postgres Types

37 PGType (..)

38 PGType (..)

38− , HasOid (..)

39 , NullityType (..)

40+ , RowType

41+ , FromType

42+ -- * Schema Types

40 , ColumnType

43 , ColumnType

41− -- * Tables

42 , ColumnsType

44 , ColumnsType

43− , RelationType

44− , NilRelation

45− , RelationsType

46 , TableType

45 , TableType

47− -- * Schema

48 , SchemumType (..)

46 , SchemumType (..)

47+ , IndexType (..)

48+ , FunctionType

49+ , OperatorType (..)

50+ , ReturnsType (..)

49 , SchemaType

51 , SchemaType

52+ , SchemasType

53+ , Public

50 -- * Constraints

54 -- * Constraints

51 , (:=>)

55 , (:=>)

52 , ColumnConstraint (..)

56 , ColumnConstraint (..)

53 , TableConstraint (..)

57 , TableConstraint (..)

54 , TableConstraints

58 , TableConstraints

55− , NilTableConstraints

56 , Uniquely

59 , Uniquely

57− -- * Aliases

58− , (:::)

59− , Alias (Alias)

60− , renderAlias

61− , renderAliases

62− , Aliased (As)

63− , Aliasable (as)

64− , renderAliasedAs

65− , AliasesOf

66− , ZipAliased (..)

67− , Has

68− , HasUnique

69− , HasAll

70− , IsLabel (..)

71− , IsQualified (..)

72 -- * Enumerated Labels

60 -- * Enumerated Labels

73 , IsPGlabel (..)

61 , IsPGlabel (..)

74 , PGlabel (..)

62 , PGlabel (..)

75− , renderLabel

63+ -- * Data Definitions

76− , renderLabels

77− -- * Grouping

78− , Grouping (..)

79− , GroupedBy

80− -- * Type Families

81− , Join

82− , With

83 , Create

64 , Create

65+ , CreateIfNotExists

66+ , CreateOrReplace

84 , Drop

67 , Drop

68+ , DropSchemum

69+ , DropIfExists

70+ , DropSchemumIfExists

85 , Alter

71 , Alter

72+ , AlterIfExists

86 , Rename

73 , Rename

87− , Elem

74+ , RenameIfExists

88− , In

75+ , ConstraintInvolves

76+ , DropIfConstraintsInvolve

77+ , IsNotElem

78+ , AllUnique

79+ -- * Type Classifications

89 , PGNum

80 , PGNum

90 , PGIntegral

81 , PGIntegral

91 , PGFloating

82 , PGFloating

92 , PGTypeOf

83 , PGTypeOf

93− , SameTypes

84+ , PGJsonType

85+ , PGJsonKey

94 , SamePGType

86 , SamePGType

95 , AllNotNull

87 , AllNotNull

96 , NotAllNull

88 , NotAllNull

89+ -- * Nullifications

97 , NullifyType

90 , NullifyType

98− , NullifyRelation

91+ , NullifyRow

99− , NullifyRelations

92+ , NullifyFrom

100− , ColumnsToRelation

93+ -- * Table Conversions

101 , TableToColumns

94 , TableToColumns

102− , TableToRelation

95+ , ColumnsToRow

103− , ConstraintInvolves

96+ , TableToRow

104− , DropIfConstraintsInvolve

105− -- * Embedding

106− , PG

107− , EnumFrom

108− , LabelsFrom

109− , CompositeFrom

110− , FieldNamesFrom

111− , FieldTypesFrom

112− , ConstructorsOf

113− , ConstructorNameOf

114− , ConstructorNamesOf

115− , FieldsOf

116− , FieldNameOf

117− , FieldNamesOf

118− , FieldTypeOf

119− , FieldTypesOf

120− , RecordCodeOf

121− , MapMaybes (..)

122− , Nulls

123− , ParamsFrom

124− , ResultFrom

125 ) where

97 ) where

126

127−import Control.DeepSeq

99+import Control.Category

128−import Data.Aeson (Value)

129−import Data.ByteString (ByteString)

130−import Data.Int (Int16, Int32, Int64)

131import Data.Kind

100import Data.Kind

132import Data.Monoid hiding (All)

101import Data.Monoid hiding (All)

133−import Data.Scientific (Scientific)

134−import Data.String

135−import Data.Text (Text)

136−import Data.Time

137−import Data.Word (Word16, Word32, Word64)

138import Data.Type.Bool

102import Data.Type.Bool

139−import Data.UUID.Types (UUID)

140import Generics.SOP

103import Generics.SOP

141−import GHC.OverloadedLabels

142import GHC.TypeLits

104import GHC.TypeLits

143−import Network.IP.Addr

105+import Prelude hiding (id, (.))

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

149

106

107+import Squeal.PostgreSQL.Alias

108+import Squeal.PostgreSQL.List

150import Squeal.PostgreSQL.Render

109import Squeal.PostgreSQL.Render

151

110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

152-- | `PGType` is the promoted datakind of PostgreSQL types.

114-- | `PGType` is the promoted datakind of PostgreSQL types.

153--

115--

154−-- >>> import Squeal.PostgreSQL.Schema

155-- >>> :kind 'PGbool

116-- >>> :kind 'PGbool

156-- 'PGbool :: PGType

117-- 'PGbool :: PGType

157data PGType

118data PGType

@@ -162,6 +123,7 @@ data PGType

162 | PGnumeric -- ^ arbitrary precision numeric type

123 | PGnumeric -- ^ arbitrary precision numeric type

163 | PGfloat4 -- ^ single precision floating-point number (4 bytes)

124 | PGfloat4 -- ^ single precision floating-point number (4 bytes)

164 | PGfloat8 -- ^ double precision floating-point number (8 bytes)

125 | PGfloat8 -- ^ double precision floating-point number (8 bytes)

126+ | PGmoney -- ^ currency amount

165 | PGchar Nat -- ^ fixed-length character string

127 | PGchar Nat -- ^ fixed-length character string

166 | PGvarchar Nat -- ^ variable-length character string

128 | PGvarchar Nat -- ^ variable-length character string

167 | PGtext -- ^ variable-length character string

129 | PGtext -- ^ variable-length character string

@@ -176,40 +138,16 @@ data PGType

176 | PGinet -- ^ IPv4 or IPv6 host address

138 | PGinet -- ^ IPv4 or IPv6 host address

177 | PGjson -- ^ textual JSON data

139 | PGjson -- ^ textual JSON data

178 | PGjsonb -- ^ binary JSON data, decomposed

140 | PGjsonb -- ^ binary JSON data, decomposed

179− | PGvararray PGType -- ^ variable length array

141+ | PGvararray NullityType -- ^ variable length array

180− | PGfixarray Nat PGType -- ^ fixed length array

142+ | PGfixarray [Nat] NullityType -- ^ fixed length array

181− | PGenum [Symbol]

143+ | PGenum [Symbol] -- ^ enumerated (enum) types are data types that comprise a static, ordered set of values.

182− | PGcomposite [(Symbol, PGType)]

144+ | PGcomposite RowType -- ^ a composite type represents the structure of a row or record; it is essentially just a list of field names and their data types.

145+ | PGtsvector -- ^ A tsvector value is a sorted list of distinct lexemes, which are words that have been normalized to merge different variants of the same word.

146+ | PGtsquery -- ^ A tsquery value stores lexemes that are to be searched for.

147+ | PGoid -- Object identifiers (OIDs) are used internally by PostgreSQL as primary keys for various system tables.

148+ | PGrange PGType -- ^ Range types are data types representing a range of values of some element type (called the range's subtype).

183 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types

149 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types

184

150

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−

213-- | `NullityType` encodes the potential presence or definite absence of a

151-- | `NullityType` encodes the potential presence or definite absence of a

214-- @NULL@ allowing operations which are sensitive to such to be well typed.

152-- @NULL@ allowing operations which are sensitive to such to be well typed.

215--

153--

@@ -228,11 +166,6 @@ data NullityType

228type (:=>) constraint ty = '(constraint,ty)

166type (:=>) constraint ty = '(constraint,ty)

229infixr 7 :=>

167infixr 7 :=>

230

168

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−

236-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.

169-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.

237-- A column can be assigned a default value.

170-- A column can be assigned a default value.

238-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also

171-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also

@@ -274,11 +207,14 @@ data TableConstraint

274 | PrimaryKey [Symbol]

207 | PrimaryKey [Symbol]

275 | ForeignKey [Symbol] Symbol [Symbol]

208 | ForeignKey [Symbol] Symbol [Symbol]

276

209

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+-}

278type TableConstraints = [(Symbol,TableConstraint)]

217type TableConstraints = [(Symbol,TableConstraint)]

279−-- | A monokinded empty `TableConstraints`.

280−type family NilTableConstraints :: TableConstraints where

281− NilTableConstraints = '[]

282

218

283-- | A `ForeignKey` must reference columns that either are

219-- | A `ForeignKey` must reference columns that either are

284-- a `PrimaryKey` or form a `Unique` constraint.

220-- a `PrimaryKey` or form a `Unique` constraint.

@@ -302,233 +238,64 @@ type family Uniquely

302-- :}

238-- :}

303type TableType = (TableConstraints,ColumnsType)

239type TableType = (TableConstraints,ColumnsType)

304

240

305−-- | `RelationType` is a row of `NullityType`

241+{- | A `RowType` is a row of `NullityType`. They correspond to Haskell

306−--

242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.

243+

307−-- >>> :{

244+>>> :{

308−-- type family PersonRelation :: RelationType where

245+type family PersonRow :: RowType where

309−-- PersonRelation =

246+ PersonRow =

310−-- '[ "name" ::: 'NotNull 'PGtext

247+ '[ "name" ::: 'NotNull 'PGtext

311−-- , "age" ::: 'NotNull 'PGint4

248+ , "age" ::: 'NotNull 'PGint4

312−-- , "dateOfBirth" ::: 'Null 'PGdate

249+ , "dateOfBirth" ::: 'Null 'PGdate

313−-- ]

250+ ]

314−-- :}

251+:}

315−type RelationType = [(Symbol,NullityType)]

252+-}

316−-- | A monokinded empty `RelationType`.

253+type RowType = [(Symbol,NullityType)]

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)]

321

254

255+{- | `FromType` is a row of `RowType`s. It can be thought of as

256+a product, or horizontal gluing and is used in `Squeal.PostgreSQL.Query.FromClause`s

257+and `Squeal.PostgreSQL.Query.TableExpression`s.

258+-}

259+type FromType = [(Symbol,RowType)]

260+

322−-- | `ColumnsToRelation` removes column constraints.

261+-- | `ColumnsToRow` removes column constraints.

323−type family ColumnsToRelation (columns :: ColumnsType) :: RelationType where

262+type family ColumnsToRow (columns :: ColumnsType) :: RowType where

324− ColumnsToRelation '[] = '[]

263+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': column5 ::: _ :=> ty5 ': columns) =

325− ColumnsToRelation (column ::: constraint :=> ty ': columns) =

264+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': ColumnsToRow columns

326− column ::: ty ': ColumnsToRelation columns

265+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': columns) =

266+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': ColumnsToRow columns

267+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': columns) =

268+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': ColumnsToRow columns

269+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': columns) =

270+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': ColumnsToRow columns

271+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': columns) =

272+ column ::: ty ': column1 ::: ty1 ': ColumnsToRow columns

273+ ColumnsToRow (column ::: _ :=> ty ': columns) =

274+ column ::: ty ': ColumnsToRow columns

275+ ColumnsToRow '[] = '[]

327

276

328-- | `TableToColumns` removes table constraints.

277-- | `TableToColumns` removes table constraints.

329type family TableToColumns (table :: TableType) :: ColumnsType where

278type family TableToColumns (table :: TableType) :: ColumnsType where

330 TableToColumns (constraints :=> columns) = columns

279 TableToColumns (constraints :=> columns) = columns

331

280

332−-- | Convert a table to a relation.

281+-- | Convert a table to a row type.

333−type family TableToRelation (table :: TableType) :: RelationType where

282+type family TableToRow (table :: TableType) :: RowType where

334− TableToRelation tab = ColumnsToRelation (TableToColumns tab)

283+ TableToRow tab = ColumnsToRow (TableToColumns tab)

335

284

336−-- | `Grouping` is an auxiliary namespace, created by

285+-- | Numeric Postgres types.

337−-- @GROUP BY@ clauses (`Squeal.PostgreSQL.Query.group`), and used

286+type PGNum =

338−-- for typesafe aggregation

287+ '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

339−data Grouping

340− = Ungrouped -- ^ no aggregation permitted

341− | Grouped [(Symbol,Symbol)] -- ^ aggregation required for any column which is not grouped

342

288

343−{- | A `GroupedBy` constraint indicates that a table qualified column is

289+-- | Floating Postgres types.

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−-- | >>> import Generics.SOP (NP(..))

377−-- >>> renderAliases (#jimbob :* #kandi :* Nil)

378−-- ["\"jimbob\"","\"kandi\""]

379−renderAliases

380− :: All KnownSymbol aliases => NP Alias aliases -> [ByteString]

381−renderAliases = hcollapse

382− . hcmap (Proxy @KnownSymbol) (K . renderAlias)

383−

384−-- | The `As` operator is used to name an expression. `As` is like a demoted

385−-- version of `:::`.

386−--

387−-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)

388−-- As (Just "hello") Alias

389−data Aliased expression aliased where

390− As

391− :: KnownSymbol alias

392− => expression ty

393− -> Alias alias

394− -> Aliased expression (alias ::: ty)

395−deriving instance Show (expression ty)

396− => Show (Aliased expression (alias ::: ty))

397−deriving instance Eq (expression ty)

398− => Eq (Aliased expression (alias ::: ty))

399−deriving instance Ord (expression ty)

400− => Ord (Aliased expression (alias ::: ty))

401−instance (alias0 ~ alias1, alias0 ~ alias2, KnownSymbol alias2)

402− => IsLabel alias0 (Aliased Alias (alias1 ::: alias2)) where

403− fromLabel = fromLabel @alias2 `As` fromLabel @alias1

404−

405−class KnownSymbol alias => Aliasable expression alias aliased where

406− as :: expression -> Alias alias -> aliased

407−instance KnownSymbol alias => Aliasable

408− (expression ty) alias (Aliased expression (alias ::: ty)) where as = As

409−instance KnownSymbol alias => Aliasable

410− (expression ty) alias (NP (Aliased expression) '[alias ::: ty])

411− where

412− expression `as` alias = expression `As` alias :* Nil

413−-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")

414−-- >>> renderAliasedAs renderMaybe (Just (3::Int) `As` #an_int)

415−-- "Just AS \"an_int\""

416−renderAliasedAs

417− :: (forall ty. expression ty -> ByteString)

418− -> Aliased expression aliased

419− -> ByteString

420−renderAliasedAs render (expression `As` alias) =

421− render expression <> " AS " <> renderAlias alias

422−

423−-- | `AliasesOf` retains the AliasesOf in a row.

424−type family AliasesOf aliaseds where

425− AliasesOf '[] = '[]

426− AliasesOf (alias ::: ty ': tys) = alias ': AliasesOf tys

427−

428−-- | The `ZipAliased` class provides a type family for zipping

429−-- `Symbol` lists together with arbitrary lists of the same size,

430−-- with an associated type family `ZipAs`, together with

431−-- a method `zipAs` for zipping heterogeneous lists of `Alias`es

432−-- together with a heterogeneous list of expressions into

433−-- a heterogeneous list of `Aliased` expressions.

434−class

435− ( SListI (ZipAs ns xs)

436− , All KnownSymbol ns

437− ) => ZipAliased ns xs where

438−

439− type family ZipAs

440− (ns :: [Symbol]) (xs :: [k]) = (zs :: [(Symbol,k)]) | zs -> ns xs

441−

442− zipAs

443− :: NP Alias ns

444− -> NP expr xs

445− -> NP (Aliased expr) (ZipAs ns xs)

446−

447−instance ZipAliased '[] '[] where

448− type ZipAs '[] '[] = '[]

449− zipAs Nil Nil = Nil

450−

451−instance

452− ( KnownSymbol n

453− , ZipAliased ns xs

454− ) => ZipAliased (n ': ns) (x ': xs) where

455− type ZipAs (n ': ns) (x ': xs) = '(n,x) ': ZipAs ns xs

456− zipAs (n :* ns) (x :* xs) = x `As` n :* zipAs ns xs

457−

458−-- | @HasUnique alias fields field@ is a constraint that proves that

459−-- @fields@ is a singleton of @alias ::: field@.

460−type HasUnique alias fields field = fields ~ '[alias ::: field]

461−

462−-- | @Has alias fields field@ is a constraint that proves that

463−-- @fields@ has a field of @alias ::: field@, inferring @field@

464−-- from @alias@ and @fields@.

465−class KnownSymbol alias =>

466− Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)

467− | alias fields -> field where

468−instance {-# OVERLAPPING #-} KnownSymbol alias

469− => Has alias (alias ::: field ': fields) field

470−instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)

471− => Has alias (field' ': fields) field

472−

473−-- | `HasAll` extends `Has` to take lists of @aliases@ and @fields@ and infer

474−-- a list of @subfields@.

475−class

476− ( All KnownSymbol aliases

477− ) => HasAll

478− (aliases :: [Symbol])

479− (fields :: [(Symbol,kind)])

480− (subfields :: [(Symbol,kind)])

481− | aliases fields -> subfields where

482−instance {-# OVERLAPPING #-} HasAll '[] fields '[]

483−instance {-# OVERLAPPABLE #-}

484− (Has alias fields field, HasAll aliases fields subfields)

485− => HasAll (alias ': aliases) fields (alias ::: field ': subfields)

486−

487−-- | Analagous to `IsLabel`, the constraint

488−-- `IsQualified` defines `!` for a column alias qualified

489−-- by a table alias.

490−class IsQualified table column expression where

491− (!) :: Alias table -> Alias column -> expression

492− infixl 9 !

493−instance IsQualified table column (Alias table, Alias column) where (!) = (,)

494−

495−-- | @Elem@ is a promoted `Data.List.elem`.

496−type family Elem x xs where

497− Elem x '[] = 'False

498− Elem x (x ': xs) = 'True

499− Elem x (_ ': xs) = Elem x xs

500−

501−-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.

502−type family In x xs :: Constraint where In x xs = Elem x xs ~ 'True

503−

504−-- | `PGNum` is a constraint on `PGType` whose

505−-- `Squeal.PostgreSQL.Expression.Expression`s have a `Num` constraint.

506−type PGNum ty =

507− In ty '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

508−

509−-- | `PGFloating` is a constraint on `PGType` whose

510−-- `Squeal.PostgreSQL.Expression.Expression`s

511−-- have `Fractional` and `Floating` constraints.

512−type PGFloating ty = In ty '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

290+type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

513−

291+

514−-- | `PGIntegral` is a constraint on `PGType` whose

292+-- | Integral Postgres types.

515−-- `Squeal.PostgreSQL.Expression.Expression`s

516−-- have `Squeal.PostgreSQL.Expression.div_` and

517−-- `Squeal.PostgreSQL.Expression.mod_` functions.

518−type PGIntegral ty = In ty '[ 'PGint2, 'PGint4, 'PGint8]

293+type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]

519

294

520-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

295-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

521type family PGTypeOf (ty :: NullityType) :: PGType where

296type family PGTypeOf (ty :: NullityType) :: PGType where

522 PGTypeOf (nullity pg) = pg

297 PGTypeOf (nullity pg) = pg

523

298

524−-- | `SameTypes` is a constraint that proves two `ColumnsType`s have the same

525−-- length and the same `ColumnType`s.

526−type family SameTypes (columns0 :: ColumnsType) (columns1 :: ColumnsType)

527− :: Constraint where

528− SameTypes '[] '[] = ()

529− SameTypes (column0 ::: def0 :=> ty0 ': columns0) (column1 ::: def1 :=> ty1 ': columns1)

530− = (ty0 ~ ty1, SameTypes columns0 columns1)

531−

532-- | Equality constraint on the underlying `PGType` of two columns.

299-- | Equality constraint on the underlying `PGType` of two columns.

533class SamePGType

300class SamePGType

534 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where

301 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where

@@ -538,39 +305,63 @@ instance ty0 ~ ty1 => SamePGType

538

305

539-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.

306-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.

540type family AllNotNull (columns :: ColumnsType) :: Constraint where

307type family AllNotNull (columns :: ColumnsType) :: Constraint where

308+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns

309+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns

310+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns

311+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns

312+ AllNotNull (_ ::: _ :=> 'NotNull _ ': _ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns

313+ AllNotNull (_ ::: _ :=> 'NotNull _ ': columns) = AllNotNull columns

541 AllNotNull '[] = ()

314 AllNotNull '[] = ()

542− AllNotNull (column ::: def :=> 'NotNull ty ': columns) = AllNotNull columns

543

315

544-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

316-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

545-- @NOT NULL@.

317-- @NOT NULL@.

546type family NotAllNull (columns :: ColumnsType) :: Constraint where

318type family NotAllNull (columns :: ColumnsType) :: Constraint where

547− NotAllNull (column ::: def :=> 'NotNull ty ': columns) = ()

319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

322+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

323+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

324+ NotAllNull (_ ::: _ :=> 'NotNull _ ': _) = ()

548− NotAllNull (column ::: def :=> 'Null ty ': columns) = NotAllNull columns

325+ NotAllNull (_ ::: _ :=> 'Null _ ': columns) = NotAllNull columns

549−

326+

550−-- | `NullifyType` is an idempotent that nullifies a `ColumnType`.

327+-- | `NullifyType` is an idempotent that nullifies a `NullityType`.

551type family NullifyType (ty :: NullityType) :: NullityType where

328type family NullifyType (ty :: NullityType) :: NullityType where

552 NullifyType ('Null ty) = 'Null ty

329 NullifyType ('Null ty) = 'Null ty

553 NullifyType ('NotNull ty) = 'Null ty

330 NullifyType ('NotNull ty) = 'Null ty

554

331

555−-- | `NullifyRelation` is an idempotent that nullifies a `ColumnsType`.

332+-- | `NullifyRow` is an idempotent that nullifies a `RowType`.

556−type family NullifyRelation (columns :: RelationType) :: RelationType where

333+type family NullifyRow (columns :: RowType) :: RowType where

557− NullifyRelation '[] = '[]

334+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': columns) =

335+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': column5 ::: NullifyType ty5 ': NullifyRow columns

336+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': columns) =

337+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': NullifyRow columns

338+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': columns) =

339+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': NullifyRow columns

340+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': columns) =

341+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': NullifyRow columns

342+ NullifyRow (column ::: ty ': column1 ::: ty1 ': columns) =

343+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': NullifyRow columns

558− NullifyRelation (column ::: ty ': columns) =

344+ NullifyRow (column ::: ty ': columns) =

559− column ::: NullifyType ty ': NullifyRelation columns

345+ column ::: NullifyType ty ': NullifyRow columns

560−

346+ NullifyRow '[] = '[]

347+

561−-- | `NullifyRelations` is an idempotent that nullifies a `RelationsType`

348+-- | `NullifyFrom` is an idempotent that nullifies a `FromType`

562-- used to nullify the left or right hand side of an outer join

349-- used to nullify the left or right hand side of an outer join

563-- in a `Squeal.PostgreSQL.Query.FromClause`.

350-- in a `Squeal.PostgreSQL.Query.FromClause`.

564−type family NullifyRelations (tables :: RelationsType) :: RelationsType where

351+type family NullifyFrom (tables :: FromType) :: FromType where

565− NullifyRelations '[] = '[]

352+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': table5 ::: columns5 ': tables) =

566− NullifyRelations (table ::: columns ': tables) =

353+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns5 ': table5 ::: NullifyRow columns4 ': NullifyFrom tables

567− table ::: NullifyRelation columns ': NullifyRelations tables

354+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': tables) =

568−

355+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns4 ': NullifyFrom tables

569−-- | `Join` is simply promoted `++` and is used in @JOIN@s in

356+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': tables) =

570−-- `Squeal.PostgreSQL.Query.FromClause`s.

357+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': NullifyFrom tables

571−type family Join xs ys where

358+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': tables) =

572− Join '[] ys = ys

359+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': NullifyFrom tables

573− Join (x ': xs) ys = x ': Join xs ys

360+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': tables) =

361+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': NullifyFrom tables

362+ NullifyFrom (table ::: columns ': tables) =

363+ table ::: NullifyRow columns ': NullifyFrom tables

364+ NullifyFrom '[] = '[]

574

365

575-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in

366-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in

576-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

367-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

@@ -580,62 +371,100 @@ type family Create alias x xs where

580 Create alias x (alias ::: y ': xs) = TypeError

371 Create alias x (alias ::: y ': xs) = TypeError

581 ('Text "Create: alias "

372 ('Text "Create: alias "

582 ':<>: 'ShowType alias

373 ':<>: 'ShowType alias

583− ':<>: 'Text "already in use")

374+ ':<>: 'Text "already exists")

584 Create alias y (x ': xs) = x ': Create alias y xs

375 Create alias y (x ': xs) = x ': Create alias y xs

585

376

377+type family CreateIfNotExists alias x xs where

378+ CreateIfNotExists alias x '[] = '[alias ::: x]

379+ CreateIfNotExists alias x (alias ::: y ': xs) = alias ::: y ': xs

380+ CreateIfNotExists alias y (x ': xs) = x ': CreateIfNotExists alias y xs

381+

382+type family CreateOrReplace alias x xs where

383+ CreateOrReplace alias x '[] = '[alias ::: x]

384+ CreateOrReplace alias x (alias ::: x ': xs) = alias ::: x ': xs

385+ CreateOrReplace alias x (alias ::: y ': xs) = TypeError

386+ ('Text "CreateOrReplace: expected type "

387+ ':<>: 'ShowType x

388+ ':<>: 'Text " but alias "

389+ ':<>: 'ShowType alias

390+ ':<>: 'Text " has type "

391+ ':<>: 'ShowType y)

392+ CreateOrReplace alias y (x ': xs) = x ': CreateOrReplace alias y xs

393+

586-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

394-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

587-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

395-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

588-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

396-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

589type family Drop alias xs where

397type family Drop alias xs where

398+ Drop alias '[] = TypeError

399+ ('Text "Drop: alias "

400+ ':<>: 'ShowType alias

401+ ':<>: 'Text " does not exist" )

590− Drop alias ((alias ::: x) ': xs) = xs

402+ Drop alias (alias ::: x ': xs) = xs

591 Drop alias (x ': xs) = x ': Drop alias xs

403 Drop alias (x ': xs) = x ': Drop alias xs

592

404

405+type family DropSchemum alias sch xs where

406+ DropSchemum alias sch '[] = TypeError

407+ ('Text "DropSchemum: alias "

408+ ':<>: 'ShowType alias

409+ ':<>: 'Text " does not exist" )

410+ DropSchemum alias sch (alias ::: sch x ': xs) = xs

411+ DropSchemum alias sch0 (alias ::: sch1 x ': xs) = TypeError

412+ ('Text "DropSchemum: expected schemum "

413+ ':<>: 'ShowType sch0

414+ ':<>: 'Text " but alias "

415+ ':<>: 'ShowType alias

416+ ':<>: 'Text " has schemum "

417+ ':<>: 'ShowType sch1)

418+ DropSchemum alias sch (x ': xs) = x ': DropSchemum alias sch xs

419+

420+type family DropIfExists alias xs where

421+ DropIfExists alias '[] = '[]

422+ DropIfExists alias (alias ::: x ': xs) = xs

423+ DropIfExists alias (x ': xs) = x ': DropIfExists alias xs

424+

425+type family DropSchemumIfExists alias sch xs where

426+ DropSchemumIfExists alias sch '[] = '[]

427+ DropSchemumIfExists alias sch (alias ::: sch x ': xs) = xs

428+ DropSchemumIfExists alias sch0 (alias ::: sch1 x ': xs) = TypeError

429+ ('Text "DropSchemumIfExists: expected schemum "

430+ ':<>: 'ShowType sch1

431+ ':<>: 'Text " but alias "

432+ ':<>: 'ShowType alias

433+ ':<>: 'Text " has schemum "

434+ ':<>: 'ShowType sch0)

435+ DropSchemumIfExists alias sch (x ': xs) = x ': DropSchemumIfExists alias sch xs

436+

593-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@

437-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@

594−-- 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`

595-- and `Squeal.PostgreSQL.Definition.alterColumn`.

439-- and `Squeal.PostgreSQL.Definition.alterColumn`.

596type family Alter alias x xs where

440type family Alter alias x xs where

441+ Alter alias x '[] = TypeError

442+ ('Text "Alter: alias "

443+ ':<>: 'ShowType alias

444+ ':<>: 'Text " does not exist" )

597 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

445 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

598 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

446 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

599

447

600−-- type family AddConstraint constraint ty where

448+type family AlterIfExists alias x xs where

601−-- AddConstraint constraint (constraints :=> ty)

449+ AlterIfExists alias x '[] = '[]

602−-- = AsSet (constraint ': constraints) :=> ty

450+ AlterIfExists alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

603−

451+ AlterIfExists alias x1 (x0 ': xs) = x0 ': AlterIfExists alias x1 xs

604−-- type family DeleteFromList (e :: elem) (list :: [elem]) where

605−-- DeleteFromList elem '[] = '[]

606−-- DeleteFromList elem (x ': xs) =

607−-- If (Cmp elem x == 'EQ) xs (x ': DeleteFromList elem xs)

608−

609−-- type family DropConstraint constraint ty where

610−-- DropConstraint constraint (constraints :=> ty)

611−-- = (AsSet (DeleteFromList constraint constraints)) :=> ty

612

452

613-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@

453-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@

614-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

454-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

615-- `Squeal.PostgreSQL.Definition.renameColumn`.

455-- `Squeal.PostgreSQL.Definition.renameColumn`.

616type family Rename alias0 alias1 xs where

456type family Rename alias0 alias1 xs where

457+ Rename alias0 alias1 '[] = TypeError

458+ ('Text "Rename: alias "

459+ ':<>: 'ShowType alias0

460+ ':<>: 'Text " does not exist" )

617 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

618 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

619

463

620−-- | `MapMaybes` is used in the binary instances of composite types.

464+type family RenameIfExists alias0 alias1 xs where

621−class MapMaybes xs where

465+ RenameIfExists alias x '[] = '[]

622− type family Maybes (xs :: [Type]) = (mxs :: [Type]) | mxs -> xs

466+ RenameIfExists alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

623− maybes :: NP Maybe xs -> NP I (Maybes xs)

467+ RenameIfExists alias0 alias1 (x ': xs) = x ': RenameIfExists alias0 alias1 xs

624− unMaybes :: NP I (Maybes xs) -> NP Maybe xs

625−instance MapMaybes '[] where

626− type Maybes '[] = '[]

627− maybes Nil = Nil

628− unMaybes Nil = Nil

629−instance MapMaybes xs => MapMaybes (x ': xs) where

630− type Maybes (x ': xs) = Maybe x ': Maybes xs

631− maybes (x :* xs) = I x :* maybes xs

632− unMaybes (I mx :* xs) = mx :* unMaybes xs

633−

634−-- | `Nulls` is used to construct a `Squeal.Postgresql.Expression.row`

635−-- of a composite type.

636−type family Nulls tys where

637− Nulls '[] = '[]

638− Nulls (field ::: ty ': tys) = field ::: 'Null ty ': Nulls tys

639

468

640-- | Check if a `TableConstraint` involves a column

469-- | Check if a `TableConstraint` involves a column

641type family ConstraintInvolves column constraint where

470type family ConstraintInvolves column constraint where

@@ -657,208 +486,111 @@ type family DropIfConstraintsInvolve column constraints where

657-- `View` or `Typedef`.

486-- `View` or `Typedef`.

658data SchemumType

487data SchemumType

659 = Table TableType

488 = Table TableType

660− | View RelationType

489+ | View RowType

661 | Typedef PGType

490 | Typedef PGType

662−

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+

663−-- | The schema of a database consists of a list of aliased,

515+{- | The schema of a database consists of a list of aliased,

664−-- user-defined `SchemumType`s.

516+user-defined `SchemumType`s.

517+

518+>>> :{

519+type family Schema :: SchemaType where

520+ Schema =

521+ '[ "users" ::: 'Table (

522+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

523+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

524+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

525+ ])

526+ , "emails" ::: 'Table (

527+ '[ "pk_emails" ::: 'PrimaryKey '["id"]

528+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

529+ ] :=>

530+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

531+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

532+ , "email" ::: 'NoDef :=> 'Null 'PGtext

533+ ])

534+ ]

535+:}

536+-}

665type SchemaType = [(Symbol,SchemumType)]

537type SchemaType = [(Symbol,SchemumType)]

666

538

667−-- | Used in `Squeal.Postgresql.Manipulation.with`.

539+{- |

668−type family With

540+A database contains one or more named schemas, which in turn contain tables.

669− (relations :: RelationsType)

541+The same object name can be used in different schemas without conflict;

670− (schema :: SchemaType)

542+for example, both schema1 and myschema can contain tables named mytable.

671− :: SchemaType where

543+Unlike databases, schemas are not rigidly separated:

672− With '[] schema = schema

544+a user can access objects in any of the schemas in the database they are connected to,

673− With (alias ::: rel ': rels) schema =

545+if they have privileges to do so.

674− alias ::: 'View rel ': With rels schema

546+

547+There are several reasons why one might want to use schemas:

548+

549+ * To allow many users to use one database without interfering with each other.

550+ * To organize database objects into logical groups to make them more manageable.

551+ * Third-party applications can be put into separate schemas

552+ so they do not collide with the names of other objects.

553+-}

554+type SchemasType = [(Symbol,SchemaType)]

555+

556+-- | A type family to use for a single schema database.

557+type family Public (schema :: SchemaType) :: SchemasType

558+ where Public schema = '["public" ::: schema]

675

559

676-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas

560-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas

677-- the overloaded label, `fromLabel` is used for column references,

561-- the overloaded label, `fromLabel` is used for column references,

678-- `label`s are used for enum terms. A `label` is called with

562-- `label`s are used for enum terms. A `label` is called with

679-- type application like `label @"beef"`.

563-- type application like `label @"beef"`.

680class IsPGlabel (label :: Symbol) expr where label :: expr

564class IsPGlabel (label :: Symbol) expr where label :: expr

681−instance label ~ label'

565+instance label ~ label1

566+ => IsPGlabel label (PGlabel label1) where label = PGlabel

567+instance labels ~ '[label]

682− => IsPGlabel label (PGlabel label') where label = PGlabel

568+ => IsPGlabel label (NP PGlabel labels) where label = PGlabel :* Nil

683-- | A `PGlabel` unit type with an `IsPGlabel` instance

569-- | A `PGlabel` unit type with an `IsPGlabel` instance

684data PGlabel (label :: Symbol) = PGlabel

570data PGlabel (label :: Symbol) = PGlabel

685−-- | Renders a label

686−renderLabel :: KnownSymbol label => proxy label -> ByteString

571+instance KnownSymbol label => RenderSQL (PGlabel label) where

687−renderLabel (_ :: proxy label) =

572+ renderSQL _ = "\'" <> renderSymbol @label <> "\'"

688− "\'" <> fromString (symbolVal (Proxy @label)) <> "\'"

689−-- | Renders a list of labels

690−renderLabels

691− :: All KnownSymbol labels => NP PGlabel labels -> [ByteString]

573+instance All KnownSymbol labels => RenderSQL (NP PGlabel labels) where

574+ renderSQL

575+ = commaSeparated

692−renderLabels = hcollapse

576+ . hcollapse

693− . hcmap (Proxy @KnownSymbol) (K . renderLabel)

577+ . hcmap (Proxy @KnownSymbol) (K . renderSQL)

694−

578+

695−-- | The `PG` type family embeds a subset of Haskell types

579+-- | Is a type a valid JSON key?

696−-- as Postgres basic types.

580+type PGJsonKey = '[ 'PGint2, 'PGint4, 'PGtext ]

697−--

581+

698−-- >>> :kind! PG LocalTime

582+-- | Is a type a valid JSON type?

699−-- PG LocalTime :: PGType

583+type PGJsonType = '[ 'PGjson, 'PGjsonb ]

700−-- = 'PGtimestamp

584+

701−type family PG (hask :: Type) :: PGType where

585+-- | Utility class for `AllUnique` to provide nicer error messages.

702− PG Bool = 'PGbool

586+class IsNotElem x isElem where

703− PG Int16 = 'PGint2

587+instance IsNotElem x 'False where

704− PG Int32 = 'PGint4

588+instance (TypeError ( 'Text "Cannot assign to "

705− PG Int64 = 'PGint8

589+ ':<>: 'ShowType alias

706− PG Word16 = 'PGint2

590+ ':<>: 'Text " more than once"))

707− PG Word32 = 'PGint4

591+ => IsNotElem '(alias, a) 'True where

708− PG Word64 = 'PGint8

592+

709− PG Scientific = 'PGnumeric

593+-- | No elem of @xs@ appears more than once, in the context of assignment.

710− PG Float = 'PGfloat4

594+class AllUnique (xs :: [(Symbol, a)]) where

711− PG Double = 'PGfloat8

595+instance AllUnique '[] where

712− PG Char = 'PGchar 1

596+instance (IsNotElem x (Elem x xs), AllUnique xs) => AllUnique (x ': xs) where

713− PG Text = 'PGtext

714− PG Lazy.Text = 'PGtext

715− PG ByteString = 'PGbytea

716− PG Lazy.ByteString = 'PGbytea

717− PG LocalTime = 'PGtimestamp

718− PG UTCTime = 'PGtimestamptz

719− PG Day = 'PGdate

720− PG TimeOfDay = 'PGtime

721− PG (TimeOfDay, TimeZone) = 'PGtimetz

722− PG DiffTime = 'PGinterval

723− PG UUID = 'PGuuid

724− PG (NetAddr IP) = 'PGinet

725− PG Value = 'PGjson

726− PG ty = TypeError

727− ('Text "There is no Postgres basic type for " ':<>: 'ShowType ty)

728−

729−-- | The `EnumFrom` type family embeds Haskell enum types, ADTs with

730−-- nullary constructors, as Postgres enum types

731−--

732−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

733−-- >>> instance Generic Schwarma

734−-- >>> instance HasDatatypeInfo Schwarma

735−-- >>> :kind! EnumFrom Schwarma

736−-- EnumFrom Schwarma :: PGType

737−-- = 'PGenum '["Beef", "Lamb", "Chicken"]

738−type family EnumFrom (hask :: Type) :: PGType where

739− EnumFrom hask = 'PGenum (LabelsFrom hask)

740−

741−-- | The `LabelsFrom` type family calculates the constructors of a

742−-- Haskell enum type.

743−--

744−-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic

745−-- >>> instance Generic Schwarma

746−-- >>> instance HasDatatypeInfo Schwarma

747−-- >>> :kind! LabelsFrom Schwarma

748−-- LabelsFrom Schwarma :: [Type.ConstructorName]

749−-- = '["Beef", "Lamb", "Chicken"]

750−type family LabelsFrom (hask :: Type) :: [Type.ConstructorName] where

751− LabelsFrom hask =

752− ConstructorNamesOf (ConstructorsOf (DatatypeInfoOf hask))

753−

754−-- | The `CompositeFrom` type family embeds Haskell record types as

755−-- Postgres composite types, as long as the record fields

756−-- are `Maybe`s of Haskell types that can be embedded as basic types

757−-- with the `PG` type family.

758−--

759−-- >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic

760−-- >>> instance Generic Row

761−-- >>> instance HasDatatypeInfo Row

762−-- >>> :kind! CompositeFrom Row

763−-- CompositeFrom Row :: PGType

764−-- = 'PGcomposite '['("a", 'PGint2), '("b", 'PGtimestamp)]

765−type family CompositeFrom (hask :: Type) :: PGType where

766− CompositeFrom hask =

767− 'PGcomposite (ZipAs (FieldNamesFrom hask) (FieldTypesFrom hask))

768−

769−-- | >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic

770−-- >>> instance Generic Row

771−-- >>> instance HasDatatypeInfo Row

772−-- >>> :kind! FieldNamesFrom Row

773−-- FieldNamesFrom Row :: [Type.FieldName]

774−-- = '["a", "b"]

775−type family FieldNamesFrom (hask :: Type) :: [Type.FieldName] where

776− FieldNamesFrom hask = FieldNamesOf (FieldsOf (DatatypeInfoOf hask))

777−

778−-- | >>> data Row = Row { a :: Maybe Int16, b :: Maybe LocalTime } deriving GHC.Generic

779−-- >>> instance Generic Row

780−-- >>> instance HasDatatypeInfo Row

781−-- >>> :kind! FieldTypesFrom Row

782−-- FieldTypesFrom Row :: [PGType]

783−-- = '['PGint2, 'PGtimestamp]

784−type family FieldTypesFrom (hask :: Type) :: [PGType] where

785− FieldTypesFrom hask = FieldTypesOf (RecordCodeOf hask (Code hask))

786−

787−-- | Calculates constructors of a datatype.

788−type family ConstructorsOf (datatype :: Type.DatatypeInfo)

789− :: [Type.ConstructorInfo] where

790− ConstructorsOf ('Type.ADT _module _datatype constructors) =

791− constructors

792− ConstructorsOf ('Type.Newtype _module _datatype constructor) =

793− '[constructor]

794−

795−-- | Calculates the name of a nullary constructor, otherwise

796−-- generates a type error.

797−type family ConstructorNameOf (constructors :: Type.ConstructorInfo)

798− :: Type.ConstructorName where

799− ConstructorNameOf ('Type.Constructor name) = name

800− ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

801− ('Text "ConstructorNameOf error: non-nullary constructor "

802− ':<>: 'Text name)

803− ConstructorNameOf ('Type.Record name _fields) = TypeError

804− ('Text "ConstructorNameOf error: non-nullary constructor "

805− ':<>: 'Text name)

806−

807−-- | Calculate the names of nullary constructors.

808−type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

809− :: [Type.ConstructorName] where

810− ConstructorNamesOf '[] = '[]

811− ConstructorNamesOf (constructor ': constructors) =

812− ConstructorNameOf constructor ': ConstructorNamesOf constructors

813−

814−-- | Calculate the fields of a datatype.

815−type family FieldsOf (datatype :: Type.DatatypeInfo)

816− :: [Type.FieldInfo] where

817− FieldsOf ('Type.ADT _module _datatype '[ 'Type.Record _name fields]) =

818− fields

819− FieldsOf ('Type.Newtype _module _datatype ('Type.Record _name fields)) =

820− fields

821−

822−-- | Calculate the name of a field.

823−type family FieldNameOf (field :: Type.FieldInfo) :: Type.FieldName where

824− FieldNameOf ('Type.FieldInfo name) = name

825−

826−-- | Calculate the names of fields.

827−type family FieldNamesOf (fields :: [Type.FieldInfo])

828− :: [Type.FieldName] where

829− FieldNamesOf '[] = '[]

830− FieldNamesOf (field ': fields) = FieldNameOf field ': FieldNamesOf fields

831−

832−-- | >>> :kind! FieldTypeOf (Maybe Int16)

833−-- FieldTypeOf (Maybe Int16) :: PGType

834−-- = 'PGint2

835−type family FieldTypeOf (maybe :: Type) where

836− FieldTypeOf (Maybe hask) = PG hask

837− FieldTypeOf ty = TypeError

838− ('Text "FieldTypeOf error: non-Maybe type " ':<>: 'ShowType ty)

839−

840−type family NullityTypeOf (hask :: Type) where

841− NullityTypeOf (Maybe hask) = 'Null (PG hask)

842− NullityTypeOf hask = 'NotNull (PG hask)

843−

844−-- | Calculate the types of fields.

845−type family FieldTypesOf (fields :: [Type]) where

846− FieldTypesOf '[] = '[]

847− FieldTypesOf (field ': fields) = FieldTypeOf field ': FieldTypesOf fields

848−

849−type family NullityTypesOf (hasks :: [Type]) where

850− NullityTypesOf '[] = '[]

851− NullityTypesOf (hask ': hasks) = NullityTypeOf hask ': NullityTypesOf hasks

852−

853−-- | Inspect the code of an algebraic datatype and ensure it's a product,

854−-- otherwise generate a type error

855−type family RecordCodeOf (hask :: Type) (code ::[[Type]]) :: [Type] where

856− RecordCodeOf _hask '[tys] = tys

857− RecordCodeOf hask _tys = TypeError

858− ('Text "RecordCodeOf error: non-Record type " ':<>: 'ShowType hask)

859−

860−type family ParamsFrom (hask :: Type) :: [NullityType] where

861− ParamsFrom hask = NullityTypesOf (RecordCodeOf hask (Code hask))

862−

863−type family ResultFrom (hask :: Type) :: RelationType where

864− ResultFrom hask = ZipAs (FieldNamesFrom hask) (ParamsFrom hask)

squeal-postgresql/src/Squeal/PostgreSQL/Transaction.hs+101−74

@@ -1,7 +1,7 @@

1{-|

2Module: Squeal.PostgreSQL.Transaction

3Description: Squeal transaction control language

4−Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

5Maintainer: eitan@morphism.tech

6Stability: experimental

@@ -9,98 +9,125 @@ Squeal transaction control language.

9-}

11{-# LANGUAGE

12+ DataKinds

12− FlexibleContexts

13+ , FlexibleContexts

13 , LambdaCase

14 , LambdaCase

14 , OverloadedStrings

15 , OverloadedStrings

16+ , TypeInType

15#-}

17#-}

17module Squeal.PostgreSQL.Transaction

19module Squeal.PostgreSQL.Transaction

18 ( -- * Transaction

20 ( -- * Transaction

19 transactionally

21 transactionally

20 , transactionally_

22 , transactionally_

23+ , transactionallyRetry

24+ , ephemerally

25+ , ephemerally_

21 , begin

26 , begin

22 , commit

27 , commit

23 , rollback

28 , rollback

24− , transactionallySchema

25− , transactionallySchema_

26 -- * Transaction Mode

29 -- * Transaction Mode

27 , TransactionMode (..)

30 , TransactionMode (..)

28 , defaultMode

31 , defaultMode

29 , longRunningMode

32 , longRunningMode

30 , IsolationLevel (..)

33 , IsolationLevel (..)

31− , renderIsolationLevel

32 , AccessMode (..)

34 , AccessMode (..)

33− , renderAccessMode

34 , DeferrableMode (..)

35 , DeferrableMode (..)

35− , renderDeferrableMode

36 ) where

38−import Control.Exception.Lifted

38+import UnliftIO

39−import Control.Monad.Base

40−import Control.Monad.Trans.Control

41−import Data.ByteString

42−import Data.Monoid

43−import Generics.SOP

44−

45−import qualified Database.PostgreSQL.LibPQ as LibPQ

47import Squeal.PostgreSQL.Manipulation

40import Squeal.PostgreSQL.Manipulation

48import Squeal.PostgreSQL.Render

41import Squeal.PostgreSQL.Render

49import Squeal.PostgreSQL.PQ

42import Squeal.PostgreSQL.PQ

50−import Squeal.PostgreSQL.Schema

52−-- | Run a schema invariant computation `transactionally`.

44+{- | Run a computation `transactionally`;

45+first `begin`,

46+then run the computation,

47+`onException` `rollback` and rethrow the exception,

48+otherwise `commit` and `return` the result.

49+-}

53transactionally

50transactionally

54− :: (MonadBaseControl IO tx, MonadPQ schema tx)

51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

55 => TransactionMode

52 => TransactionMode

56 -> tx x -- ^ run inside a transaction

53 -> tx x -- ^ run inside a transaction

57 -> tx x

54 -> tx x

58transactionally mode tx = mask $ \restore -> do

55transactionally mode tx = mask $ \restore -> do

59− _ <- begin mode

56+ manipulate_ $ begin mode

60− result <- restore tx `onException` rollback

57+ result <- restore tx `onException` (manipulate_ rollback)

61− _ <- commit

58+ manipulate_ commit

62 return result

59 return result

64−-- | Run a schema invariant computation `transactionally_` in `defaultMode`.

61+-- | Run a computation `transactionally_`, in `defaultMode`.

65transactionally_

62transactionally_

66− :: (MonadBaseControl IO tx, MonadPQ schema tx)

63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

67 => tx x -- ^ run inside a transaction

64 => tx x -- ^ run inside a transaction

68 -> tx x

65 -> tx x

69transactionally_ = transactionally defaultMode

66transactionally_ = transactionally defaultMode

71−-- | @BEGIN@ a transaction.

68+{- |

69+`transactionallyRetry` a computation;

70+

71+* first `begin`,

72+* then `try` the computation,

73+ - if it raises a serialization failure then `rollback` and restart the transaction,

74+ - if it raises any other exception then `rollback` and rethrow the exception,

75+ - otherwise `commit` and `return` the result.

76+-}

77+transactionallyRetry

78+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

72−begin :: MonadPQ schema tx => TransactionMode -> tx (K Result NilRelation)

79+ => TransactionMode

73−begin mode = manipulate . UnsafeManipulation $

80+ -> tx x -- ^ run inside a transaction

74− "BEGIN" <+> renderTransactionMode mode <> ";"

81+ -> tx x

82+transactionallyRetry mode tx = mask $ \restore ->

83+ loop . try $ do

84+ x <- restore tx

85+ manipulate_ commit

86+ return x

87+ where

88+ loop attempt = do

89+ manipulate_ $ begin mode

90+ attempt >>= \case

91+ Left (PQException (PQState _ (Just "40001") _)) -> do

92+ manipulate_ rollback

93+ loop attempt

94+ Left err -> do

95+ manipulate_ rollback

96+ throwIO err

97+ Right x -> return x

98+

99+{- | Run a computation `ephemerally`;

100+Like `transactionally` but always `rollback`, useful in testing.

101+-}

102+ephemerally

103+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

104+ => TransactionMode

105+ -> tx x -- ^ run inside an ephemeral transaction

106+ -> tx x

107+ephemerally mode tx = mask $ \restore -> do

108+ manipulate_ $ begin mode

109+ result <- restore tx `onException` (manipulate_ rollback)

110+ manipulate_ rollback

111+ return result

112

76−-- | @COMMIT@ a schema invariant transaction.

113+{- | Run a computation `ephemerally` in `defaultMode`. -}

77−commit :: MonadPQ schema tx => tx (K Result NilRelation)

114+ephemerally_

78−commit = manipulate $ UnsafeManipulation "COMMIT;"

115+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

116+ => tx x -- ^ run inside an ephemeral transaction

117+ -> tx x

118+ephemerally_ = ephemerally defaultMode

119+

120+-- | @BEGIN@ a transaction.

121+begin :: TransactionMode -> Manipulation_ schemas () ()

122+begin mode = UnsafeManipulation $ "BEGIN" <+> renderSQL mode

123

80−-- | @ROLLBACK@ a schema invariant transaction.

124+-- | @COMMIT@ a transaction.

81−rollback :: MonadPQ schema tx => tx (K Result NilRelation)

125+commit :: Manipulation_ schemas () ()

82−rollback = manipulate $ UnsafeManipulation "ROLLBACK;"

126+commit = UnsafeManipulation "COMMIT"

127

84−-- | Run a schema changing computation `transactionallySchema`.

128+-- | @ROLLBACK@ a transaction.

85−transactionallySchema

129+rollback :: Manipulation_ schemas () ()

86− :: MonadBaseControl IO io

130+rollback = UnsafeManipulation "ROLLBACK"

87− => TransactionMode

88− -> PQ schema0 schema1 io x

89− -> PQ schema0 schema1 io x

90−transactionallySchema mode u = PQ $ \ conn -> mask $ \ restore -> do

91− _ <- liftBase . LibPQ.exec (unK conn) $

92− "BEGIN" <+> renderTransactionMode mode <> ";"

93− x <- restore (unPQ u conn)

94− `onException` (liftBase (LibPQ.exec (unK conn) "ROLLBACK"))

95− _ <- liftBase $ LibPQ.exec (unK conn) "COMMIT"

96− return x

97−

98−-- | Run a schema changing computation `transactionallySchema_` in `DefaultMode`.

99−transactionallySchema_

100− :: MonadBaseControl IO io

101− => PQ schema0 schema1 io x

102− -> PQ schema0 schema1 io x

103−transactionallySchema_ = transactionallySchema defaultMode

104

131

105-- | The available transaction characteristics are the transaction `IsolationLevel`,

132-- | The available transaction characteristics are the transaction `IsolationLevel`,

106-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

133-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

@@ -113,7 +140,7 @@ data TransactionMode = TransactionMode

113-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

140-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

114-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

141-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

115defaultMode :: TransactionMode

142defaultMode :: TransactionMode

116−defaultMode = TransactionMode Serializable ReadWrite NotDeferrable

143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable

117

144

118-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

145-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

119-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

146-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

@@ -122,12 +149,12 @@ longRunningMode :: TransactionMode

122longRunningMode = TransactionMode Serializable ReadOnly Deferrable

149longRunningMode = TransactionMode Serializable ReadOnly Deferrable

123

150

124-- | Render a `TransactionMode`.

151-- | Render a `TransactionMode`.

125−renderTransactionMode :: TransactionMode -> ByteString

152+instance RenderSQL TransactionMode where

126−renderTransactionMode mode =

153+ renderSQL mode =

127− "ISOLATION LEVEL"

154+ "ISOLATION LEVEL"

128− <+> renderIsolationLevel (isolationLevel mode)

155+ <+> renderSQL (isolationLevel mode)

129− <+> renderAccessMode (accessMode mode)

156+ <+> renderSQL (accessMode mode)

130− <+> renderDeferrableMode (deferrableMode mode)

157+ <+> renderSQL (deferrableMode mode)

131

158

132-- | The SQL standard defines four levels of transaction isolation.

159-- | The SQL standard defines four levels of transaction isolation.

133-- The most strict is `Serializable`, which is defined by the standard in a paragraph

160-- The most strict is `Serializable`, which is defined by the standard in a paragraph

@@ -178,12 +205,12 @@ data IsolationLevel

178 deriving (Show, Eq)

205 deriving (Show, Eq)

179

206

180-- | Render an `IsolationLevel`.

207-- | Render an `IsolationLevel`.

181−renderIsolationLevel :: IsolationLevel -> ByteString

208+instance RenderSQL IsolationLevel where

182−renderIsolationLevel = \case

209+ renderSQL = \case

183− Serializable -> "SERIALIZABLE"

210+ Serializable -> "SERIALIZABLE"

184− ReadCommitted -> "READ COMMITTED"

211+ ReadCommitted -> "READ COMMITTED"

185− ReadUncommitted -> "READ UNCOMMITTED"

212+ ReadUncommitted -> "READ UNCOMMITTED"

186− RepeatableRead -> "REPEATABLE READ"

213+ RepeatableRead -> "REPEATABLE READ"

187

214

188-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

215-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

189-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

216-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

@@ -200,10 +227,10 @@ data AccessMode

200 deriving (Show, Eq)

227 deriving (Show, Eq)

201

228

202-- | Render an `AccessMode`.

229-- | Render an `AccessMode`.

203−renderAccessMode :: AccessMode -> ByteString

230+instance RenderSQL AccessMode where

204−renderAccessMode = \case

231+ renderSQL = \case

205− ReadWrite -> "READ WRITE"

232+ ReadWrite -> "READ WRITE"

206− ReadOnly -> "READ ONLY"

233+ ReadOnly -> "READ ONLY"

207

234

208-- | The `Deferrable` transaction property has no effect

235-- | The `Deferrable` transaction property has no effect

209-- unless the transaction is also `Serializable` and `ReadOnly`.

236-- unless the transaction is also `Serializable` and `ReadOnly`.

@@ -219,7 +246,7 @@ data DeferrableMode

219 deriving (Show, Eq)

246 deriving (Show, Eq)

220

247

221-- | Render a `DeferrableMode`.

248-- | Render a `DeferrableMode`.

222−renderDeferrableMode :: DeferrableMode -> ByteString

249+instance RenderSQL DeferrableMode where

223−renderDeferrableMode = \case

250+ renderSQL = \case

224− Deferrable -> "DEFERRABLE"

251+ Deferrable -> "DEFERRABLE"

225− NotDeferrable -> "NOT DEFERRABLE"

252+ NotDeferrable -> "NOT DEFERRABLE"

squeal-postgresql/test/Doc.hsnew file+6

@@ -0,0 +1,6 @@

1+module Main (main) where

3+import Test.DocTest

5+main :: IO ()

6+main = doctest [ "-isrc", "src" ]

squeal-postgresql/test/DocTest.hsdeleted−18

@@ -1,18 +0,0 @@

1−module Main (main) where

2−

3−import Test.DocTest

4−

5−main :: IO ()

6−main = doctest

7− [ "-isrc"

8− , "src/Squeal/PostgreSQL.hs"

9− , "src/Squeal/PostgreSQL/Binary.hs"

10− , "src/Squeal/PostgreSQL/Definition.hs"

11− , "src/Squeal/PostgreSQL/Manipulation.hs"

12− , "src/Squeal/PostgreSQL/Query.hs"

13− , "src/Squeal/PostgreSQL/Expression.hs"

14− , "src/Squeal/PostgreSQL/PQ.hs"

15− , "src/Squeal/PostgreSQL/Migration.hs"

16− , "src/Squeal/PostgreSQL/Transaction.hs"

17− , "src/Squeal/PostgreSQL/Pool.hs"

18− ]

squeal-postgresql/test/Property.hsnew file+166

@@ -0,0 +1,166 @@

1+{-# LANGUAGE

2+ DataKinds

3+ , GADTs

4+ , LambdaCase

5+ , OverloadedLabels

6+ , OverloadedStrings

7+ , TypeApplications

8+ , TypeOperators

9+#-}

10+

11+module Main (main) where

12+

13+import Control.Monad.Trans

14+import Data.ByteString (ByteString)

15+import Data.ByteString.Char8 (unpack)

16+import Data.Scientific (fromFloatDigits)

17+import Data.Fixed (Fixed(MkFixed), Micro, Pico)

18+import Data.String (IsString(fromString))

19+import Data.Time

20+import Squeal.PostgreSQL hiding (check, defaultMain, Group)

21+import Hedgehog hiding (Range)

22+import qualified Hedgehog.Gen as Gen

23+import qualified Hedgehog.Main as Main

24+import qualified Hedgehog.Range as Range

25+

26+main :: IO ()

27+main = Main.defaultMain [checkSequential roundtrips]

28+

29+roundtrips :: Group

30+roundtrips = Group "roundtrips"

31+ [ roundtrip int2 genInt16

32+ , roundtrip int4 genInt32

33+ , roundtrip int8 genInt64

34+ , roundtrip bool Gen.bool

35+ , roundtrip numeric genScientific

36+ , roundtrip float4 genFloat

37+ , roundtrip float8 genDouble

38+ , roundtripOn normalizeTimeOfDay time genTimeOfDay

39+ -- , roundtrip timetz genTimeWithZone normalizeTimeWithZone

40+ , roundtripOn normalizeLocalTime timestamp genLocalTime

41+ , roundtrip timestamptz genUTCTime

42+ , roundtrip date genDay

43+ , roundtrip interval genDiffTime

44+ , roundtripOn normalizeIntRange int4range (genRange genInt32)

45+ , roundtripOn normalizeIntRange int8range (genRange genInt64)

46+ , roundtrip numrange (genRange genScientific)

47+ , roundtripOn (fmap normalizeLocalTime) tsrange (genRange genLocalTime)

48+ , roundtrip tstzrange (genRange genUTCTime)

49+ , roundtripOn normalizeIntRange daterange (genRange genDay)

50+ ]

51+ where

52+ genInt16 = Gen.int16 Range.exponentialBounded

53+ genInt32 = Gen.int32 Range.exponentialBounded

54+ genInt64 = Gen.int64 Range.exponentialBounded

55+ genScientific = fromFloatDigits <$> genFloat

56+ genPosFloat = Gen.float

57+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)

58+ genFloat = Gen.prune $ Gen.choice

59+ [ genPosFloat

60+ , negate <$> genPosFloat

61+ , Gen.element [0,1/0] ]

62+ genPosDouble = Gen.double

63+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)

64+ genDouble = Gen.prune $ Gen.choice

65+ [ genPosDouble

66+ , negate <$> genPosDouble

67+ , Gen.element [0,1/0] ]

68+ genRange gen = do

69+ lb <- gen

70+ ub <- Gen.filter (lb <) gen

71+ Gen.element

72+ [ Empty, singleton lb, whole

73+ , lb <=..<= ub , lb <=..< ub, lb <..<= ub, lb <..< ub

74+ , atLeast lb, moreThan lb, atMost ub, lessThan ub ]

75+ genDay = do

76+ y <- toInteger <$> Gen.int (Range.constant 2000 2019)

77+ m <- Gen.int (Range.constant 1 12)

78+ d <- Gen.int (Range.constant 1 28)

79+ return $ fromGregorian y m d

80+ genDiffTime = secondsToDiffTime . toInteger <$>

81+ Gen.int (Range.constant 0 86401)

82+ genUTCTime = UTCTime <$> genDay <*> genDiffTime

83+ genTimeOfDay = do

84+ h <- Gen.int (Range.constant 0 23)

85+ m <- Gen.int (Range.constant 0 59)

86+ s <- MkFixed . toInteger <$> Gen.int (Range.constant 0 59)

87+ return $ TimeOfDay h m s

88+ genLocalTime = LocalTime <$> genDay <*> genTimeOfDay

89+ -- genTimeZone = Gen.element $ map (read @TimeZone)

90+ -- [ "UTC", "UT", "GMT", "EST", "EDT", "CST"

91+ -- , "CDT", "MST", "MDT", "PST", "PDT" ]

92+ -- genTimeWithZone = (,) <$> genTimeOfDay <*> genTimeZone

93+

94+roundtrip

95+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)

96+ => TypeExpression schemas ('NotNull ty)

97+ -> Gen x

98+ -> (PropertyName, Property)

99+roundtrip = roundtripOn id

100+

101+roundtripOn

102+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)

103+ => (x -> x)

104+ -> TypeExpression schemas ('NotNull ty)

105+ -> Gen x

106+ -> (PropertyName, Property)

107+roundtripOn norm ty gen = propertyWithName $ do

108+ x <- forAll gen

109+ Just (Only y) <- lift . withConnection connectionString $

110+ firstRow =<< runQueryParams

111+ (values_ (parameter @1 ty `as` #fromOnly)) (Only x)

112+ norm x === y

113+ where

114+ propertyWithName prop =

115+ (fromString (unpack (renderSQL ty)), property prop)

116+

117+maxPosFloat :: RealFloat a => a

118+maxPosFloat = x

119+ where

120+ n = floatDigits x

121+ b = floatRadix x

122+ (_, u) = floatRange x

123+ x = encodeFloat (b^n - 1) (u - n)

124+

125+minPosFloat :: RealFloat a => a

126+minPosFloat = x

127+ where

128+ n = floatDigits x

129+ b = floatRadix x

130+ (l, _) = floatRange x

131+ x = encodeFloat (b^n - 1) (l - n - 1)

132+

133+connectionString :: ByteString

134+connectionString = "host=localhost port=5432 dbname=exampledb"

135+

136+normalizeIntRange :: (Enum int, Ord int) => Range int -> Range int

137+normalizeIntRange = \case

138+ Empty -> Empty

139+ NonEmpty l u ->

140+ let

141+ l' = normalizeL l

142+ u' = normalizeU u

143+ in if emptyNormalized l' u' then Empty else NonEmpty l' u'

144+ where

145+ normalizeL = \case

146+ Open l -> Closed (succ l)

147+ normalized -> normalized

148+ normalizeU = \case

149+ Closed u -> Open (succ u)

150+ normalized -> normalized

151+ emptyNormalized (Closed l) (Open u) = l >= u

152+ emptyNormalized _ _ = False

153+

154+normalizeTimeOfDay :: TimeOfDay -> TimeOfDay

155+normalizeTimeOfDay (TimeOfDay h m s) = TimeOfDay h m

156+ . fromRational @Pico

157+ . toRational @Micro

158+ . fromRational @Micro

159+ . toRational @Pico

160+ $ s

161+

162+normalizeLocalTime :: LocalTime -> LocalTime

163+normalizeLocalTime (LocalTime d t) = LocalTime d (normalizeTimeOfDay t)

164+

165+-- normalizeTimeWithZone :: (TimeOfDay, TimeZone) -> (TimeOfDay, TimeZone)

166+-- normalizeTimeWithZone (t, z) = (normalizeTimeOfDay t, z)

squeal-postgresql/test/Spec.hsnew file+136

@@ -0,0 +1,136 @@

1+{-# LANGUAGE

2+ DataKinds

3+ , DeriveAnyClass

4+ , DeriveGeneric

5+ , DerivingStrategies

6+ , DuplicateRecordFields

7+ , FlexibleContexts

8+ , OverloadedLabels

9+ , OverloadedLists

10+ , OverloadedStrings

11+ , TypeApplications

12+ , TypeFamilies

13+ , TypeInType

14+ , TypeOperators

15+#-}

16+

17+module Main (main) where

18+

19+import Control.Concurrent.Async (replicateConcurrently)

20+import Data.ByteString (ByteString)

21+import Data.Int (Int32)

22+import Data.Text (Text)

23+import Test.Hspec

24+

25+import qualified Generics.SOP as SOP

26+import qualified GHC.Generics as GHC

27+

28+import Squeal.PostgreSQL

29+

30+main :: IO ()

31+main = hspec spec

32+

33+type Schemas = Public

34+ '[ "users" ::: 'Table (

35+ '[ "pk_users" ::: 'PrimaryKey '["id"]

36+ , "unique_names" ::: 'Unique '["name"]

37+ ] :=>

38+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

39+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext ] ) ]

40+

41+data User = User

42+ { userName :: Text

43+ } deriving stock (Eq, Show, GHC.Generic)

44+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

45+

46+insertUser :: Manipulation_ Schemas User ()

47+insertUser = insertInto_ #users

48+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))

49+

50+setup :: Definition (Public '[]) Schemas

51+setup =

52+ createTable #users

53+ ( serial `as` #id :*

54+ notNullable text `as` #name )

55+ ( primaryKey #id `as` #pk_users :*

56+ unique #name `as` #unique_names )

57+

58+teardown :: Definition Schemas (Public '[])

59+teardown = dropTable #users

60+

61+silence :: MonadPQ schemas pq => pq ()

62+silence = manipulate_ $

63+ UnsafeManipulation "SET client_min_messages TO WARNING;"

64+

65+setupDB :: IO ()

66+setupDB = withConnection connectionString $

67+ silence & pqThen (define setup)

68+

69+dropDB :: IO ()

70+dropDB = withConnection connectionString $

71+ silence & pqThen (define teardown)

72+

73+connectionString :: ByteString

74+connectionString = "host=localhost port=5432 dbname=exampledb"

75+

76+spec :: Spec

77+spec = before_ setupDB . after_ dropDB $ do

78+

79+ describe "Exceptions" $ do

80+

81+ let

82+ testUser = User "TestUser"

83+ newUser = manipulateParams_ insertUser

84+ insertUserTwice = newUser testUser >> newUser testUser

85+ err23505 = PQException $ PQState FatalError (Just "23505")

86+ (Just "ERROR: duplicate key value violates unique constraint \"unique_names\"\nDETAIL: Key (name)=(TestUser) already exists.\n")

87+

88+ it "should be thrown for constraint violation" $

89+ withConnection connectionString insertUserTwice

90+ `shouldThrow` (== err23505)

91+

92+ it "should be rethrown for constraint violation in a transaction" $

93+ withConnection connectionString (transactionally_ insertUserTwice)

94+ `shouldThrow` (== err23505)

95+

96+ describe "Pools" $

97+

98+ it "should manage concurrent transactions" $ do

99+ pool <- createConnectionPool

100+ "host=localhost port=5432 dbname=exampledb" 1 0.5 10

101+ let

102+ query :: Query_ (Public '[]) () (Only Char)

103+ query = values_ (literal 'a' `as` #fromOnly)

104+ session = usingConnectionPool pool . transactionally_ $ do

105+ result <- runQuery query

106+ Just (Only chr) <- firstRow result

107+ return chr

108+ chrs <- replicateConcurrently 10 session

109+ chrs `shouldSatisfy` all (== 'a')

110+

111+ describe "Ranges" $

112+

113+ it "should correctly decode ranges" $ do

114+

115+ rangesOut <- withConnection connectionString $ do

116+ let

117+ query :: Query_ (Public '[]) () (Only (Range Int32))

118+ query = values

119+ ( range int4range (atLeast 3) `as` #fromOnly )

120+ [ range int4range (3 <=..< 5) `as` #fromOnly

121+ , range int4range Empty `as` #fromOnly

122+ , range int4range whole `as` #fromOnly ]

123+ getRows =<< runQuery query

124+ (fromOnly <$> rangesOut :: [Range Int32]) `shouldBe`

125+ [ atLeast 3, 3 <=..< 5, Empty, whole ]

126+

127+ describe "Parameters" $ do

128+

129+ it "should run queries that don't reference all their parameters" $ do

130+

131+ out <- withConnection connectionString $ do

132+ let

133+ query :: Query_ (Public '[]) (Char,Int32) (Only Int32)

134+ query = values_ (param @2 `as` #fromOnly)

135+ firstRow =<< runQueryParams query ('a', 3 :: Int32)

136+ (fromOnly <$> out :: Maybe Int32) `shouldBe` Just 3

squeal-presentation-raveline.mdnew file+794

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1+# Squeal

3+_A bridge between SQL and Haskell_

5+by [@Raveline](https://github.com/raveline)

7+---

9+# Rationale

10+

11+Using `postgresql-simple` you have a typical "Trial, error, despair" workflow:

12+

13+- Write query manually or semi-automatically

14+

15+- Write haskell code using the query

16+

17+- Pray that the query syntax is correct

18+

19+- Pray that it returns what you want

20+

21+- Realize the inefficiency of prayer when it comes to SQL

22+

23+- Iterate till it works

24+

25+---

26+

27+![Can't take this anymore](http://gif.eraveline.eu/static/img/0x16e.gif)

28+

29+---

30+

31+# Use your best friend: GHC

32+

33+Squeal provides several eDSL to make your SQL typesafe:

34+

35+- Type level eDSL to express schema;

36+

37+- Value level eDSL to manipulate schema (plus migration, yeehaw !);

38+

39+- Type level eDSL to express queries;

40+

41+- Value level eDSL to perform queries

42+

43+However, it's not an ORM. There's no caching, lazy loading - you retain control over your memory. Also, joins - and mostly aggregation after joins - have to be handled manually.

44+

45+---

46+

47+# Part I. Schema & migration

48+

49+---

50+

51+# The Schema

52+

53+- The schema will be used to validate _everything_: migration, queries, etc.

54+

55+- A schema is mostly a collection of tables.

56+

57+- In this presentation, we will create a very basic database modeling a parliament. We will store _members of parliament_ and _parliamentary groups_.

58+

59+- A simple Schema to represent a Parliament could be:

60+

61+```haskell

62+type Schema = '[ "mp" ::: 'Table MemberOfParliament

63+ , "groupp" ::: 'Table ParliamentGroup ]

64+```

65+

66+---

67+

68+> _note_ We need the `DataKinds` extension to be able to express heterogenous lists containing

69+> specific types like this one.

70+

71+> You can perfectly call your table "group" and not "groupp" even though it is a

72+> keyword in SQL - Squeal queries will be properly escaped.

73+

74+---

75+

76+# A small example

77+

78+```haskell

79+type ParliamentaryGroup =

80+ '[ "pk_groupp" ::: 'PrimaryKey '["groupp_id"]]

81+ :=>

82+ '[ "groupp_id" ::: 'NoDef :=> 'NotNull 'PGuuid

83+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

84+ ]

85+```

86+

87+- That's a whole simple table defined in one go.

88+

89+- `:::` lets us define a column or a constraint.

90+

91+- `:=>` associates the constraints to the column.

92+

93+- Let's split constraints and column to study the syntax a bit more.

94+

95+---

96+

97+> _note_ We are using `:::` and `:=>` to quickly express associations when writing

98+> our schema. We need the `TypeOperators` extension.]

99+

100+---

101+

102+![What does this means ?!](http://gif.eraveline.eu/static/img/0x27e.gif)

103+

104+---

105+

106+# Defining a table

107+

108+```haskell

109+type MemberOfParliament =

110+ '[ "pk_mp" ::: 'PrimaryKey '["mp_id"]

111+ , "fk_mp_groupp" ::: 'ForeignKey '["mp_group"] "groupp" '["groupp_id"]

112+ ] :=> MpCols

113+```

114+

115+- A table is a collection of constraints associated to a collection of columns.

116+

117+- We defined a table named "mp".

118+

119+- It has a constraint named "pk_mp", defining its primary key on column "mp_id".

120+

121+- It has a constraint named "fk_mp_groupp" defining a foreign key on column "mg_group", connected to the column "groupp_id" of table "groupp".

122+

123+- These constraints will be associated to the columns defined in `MpCols`.

124+

125+---

126+

127+# Defining columns

128+

129+```haskell

130+type MpCols =

131+ '[ "mp_id" ::: 'NoDef :=> 'NotNull 'PGuuid

132+ , "first_name" ::: 'NoDef :=> 'NotNull 'PGtext

133+ , "last_name" ::: 'NoDef :=> 'NotNull 'PGtext

134+ ]

135+```

136+

137+- A listing of column associate, for each element:

138+

139+ * a name;

140+

141+ * the mention of an eventual default value;

142+

143+ * the nullability;

144+

145+ * the type (obviously).

146+

147+---

148+

149+> _note_ GHC is already helping. If I named the "mp_id" column differently,

150+> GHC would yell because I promised a primary key constraint on a column named `mp_id`, so there must be one.]

151+

152+---

153+

154+# Implementating the schema

155+

156+- We will carry this schema type pretty much everywhere.

157+

158+- But before we play with this schema, we need to implement it.

159+

160+---

161+

162+```haskell

163+setup :: Definition '[] Schema

164+setup =

165+ createTable #groupp

166+ ( notNullable uuid `as` #groupp_id

167+ :* notNullable text `as` #name)

168+ ( primaryKey #groupp_id `as` #pk_groupp )

169+ >>> createTable #mp

170+ ( notNullable uuid `as` #mp_id

171+ :* notNullable text `as` #first_name

172+ :* notNullable text `as` #last_name

173+ :* notNullable text `as` #mp_group)

174+ ( primaryKey #mp_id `as` #pk_mp

175+ :* foreignKey #mp_group #groupp #groupp_id

176+ OnDeleteCascade OnUpdateCascade

177+ `as` #fk_mp_groupp)

178+```

179+

180+---

181+

182+# Damn, that's verbose

183+

184+- Yes. But you need verbosity to get type safety.

185+

186+- On the plus side, it's fairly straightforward.

187+

188+- You use `:*` to compose the element of the heterogenous list of columns.

189+

190+- You use `>>>` to compose table creation.

191+

192+> _note_ The compiler will catch any mistype between Schema and

193+> definition; wrong nullability, wrong type, wrong name, etc.

194+

195+---

196+

197+> _note_ You'll also need `OverloadedLabels`, for naming stuff.

198+> This is mostly to avoid having to write manual proxies all

199+> the time and for convenience.

200+

201+---

202+

203+# Setting up the schema

204+

205+- Squeal comes with a very good migration manager, handling _upgrades_ AND

206+_downgrades_.

207+

208+- A migration is a simple type:

209+

210+```haskell

211+Migration io schema0 schema1

212+```

213+

214+- The first parameter is a BaseMonad (typically, IO).

215+

216+- The second parameter is "the current schema of your DB".

217+

218+- The last one is "what you will migrate to".

219+

220+- The `Definition` type used to define upgrade and downgrade functions use the

221+ same logic (from one schema to the other).

222+

223+---

224+

225+# Defining our first migration

226+

227+- We have the setup bit, we need the teardown:

228+

229+```haskell

230+tearDown :: Definition Schema '[]

231+tearDown = dropTable #mp >>> dropTable #groupp

232+```

233+

234+> _note_ GHC will also detect the _proper_ order of what you typed in

235+> downgrade and upgrade should there be any conflict (with foreign keys).

236+

237+```haskell

238+initDB :: Migration IO '[] Schema

239+initDB =

240+ Migration { name = "Schema creation"

241+ , up = void $ define setup

242+ , down = void $ define tearDown }

243+```

244+

245+---

246+

247+# Simple migrator example

248+

249+```haskell

250+main :: IO ()

251+main = do

252+ printSQL setup

253+ void $ withConnection connectionString $

254+ migrateUp $ single initDB

255+```

256+

257+- We print the migration query; you can do this for all queries generated through Squeal.

258+

259+- We use `migrateUp` to perform the migration.

260+

261+- You can run several migration at the same time, to run only one use `single`.

262+

263+---

264+

265+![That was easy](http://gif.eraveline.eu/static/img/0x47f.gif)

266+

267+---

268+

269+# Part II. Insertions

270+

271+---

272+

273+# Manipulations & Queries

274+

275+Besides the specific case of migration, you will mostly perform:

276+

277+- `Manipulation` : inserting, updating and deleting data.

278+

279+- `Query` : fetching data.

280+

281+- Both types are parametric over the same things:

282+

283+ * A schema

284+

285+ * Input parameters

286+

287+ * Output

288+

289+- Simplified, they look like this:

290+

291+```haskell

292+Manipulation schema params columns

293+

294+Query schema params columns

295+```

296+

297+

298+---

299+

300+# Our Haskell model

301+

302+```haskell

303+type Parliament = [Group]

304+

305+data Group =

306+ Group { name :: Text

307+ , members :: [MemberOfParliament] }

308+

309+data MemberOfParliament =

310+ MemberOfParliament { firstName :: Text

311+ , lastName :: Text }

312+```

313+

314+> _note_ We didn't use anything from Squeal.

315+> The model can be entirely separated from the persistence layer.

316+

317+---

318+

319+# Inserting a Parliamentary Group

320+

321+- A group is very simple: it's a uuid and a name. Let's define our params:

322+

323+```haskell

324+type GroupInsertionParams = '[ 'NotNull 'PGuuid

325+ , 'NotNull 'PGtext ]

326+```

327+

328+- Params are not named, but they are indexed. You just need nullability and type.

329+

330+---

331+

332+```haskell

333+groupInsertion :: Manipulation Schema GroupInsertionParams '[]

334+groupInsertion =

335+ insertRow_ #groupp ( Set (param @1) `as` #groupp_id

336+ :* Set (param @2) `as` #name )

337+```

338+

339+---

340+

341+- `TypeApplication` lets us use the index of parameters (counting from 1).

342+

343+- Once again: all this is checked by the compiler. Wrong name, wrong type... you'll get a compile error.

344+

345+- `insertRow_` is a simplified version of `insertRow`. `insertRow` lets you express a `RETURNING` clause and the expected behaviour in case of conflict.

346+

347+---

348+

349+_Inserting a Member of Parliament_

350+# Doing an INSERT INTO ... SELECT

351+

352+- We could create a naive query that takes MP uuid, first name, last name and group uuid...

353+

354+---

355+

356+- But that's boring. So let's use the `INSERT INTO ... SELECT`.

357+

358+---

359+

360+- We will build a query that will return as constants our MP's uuid, first name and last name...

361+

362+---

363+

364+- ... and fetch the uuid of a group given the name of the group.

365+

366+---

367+

368+- There's a `insertQuery` utility function for that. All we have to do is write the `select` !

369+

370+```haskell

371+mpInsertion :: Manipulation Schema MpParams '[]

372+mpInsertion =

373+ insertQuery_ #mp selectGroup -- we just have to write selectGroup !

374+```

375+

376+---

377+

378+_Inserting a Member of Parliament_

379+# The query type

380+

381+- A query looks just like a `Manipulation`:

382+

383+```haskell

384+Query schema params returns

385+```

386+

387+- Returns use a special syntax, that demands names, nullability and types:

388+

389+```haskell

390+type ExampleReturnType = '[ "some_column" ::: 'NotNull 'PGuuid

391+ , "other_column" ::: 'Null 'PGtext ]

392+```

393+

394+- It is not the same as the column definition we used in the schema. That one also expects that you specify, for each column, an eventual default:

395+

396+```haskell

397+type ExampleSchemaCols =

398+ '[ "some_column" ::: 'NoDef :=> 'NotNull 'PGuuid

399+ , "other_column" ::: 'NoDef :=> 'Null 'PGtext ]

400+```

401+

402+---

403+

404+_Inserting a Member of Parliament_

405+# Don't rewrite column definitions

406+

407+- We want our return type to be "all columns from table MP expressed as return type".

408+

409+- But we cannot reuse our neat `MpCols` alias, since the type do not match as we've just seen.

410+

411+- Hopefully, there's a neat Type Family that will let you convert any table you defined to the type of the equivalent row: `TableToRow`.

412+

413+- We finally have the signature for our SELECT query.

414+

415+```haskell

416+selectGroup :: Query Schema MpParams (TableToRow MemberOfParliament)

417+```

418+

419+---

420+

421+_Inserting a Member of Parliament_

422+# Our final Select query

423+

424+- Our intermediate query looks like this:

425+

426+```haskell

427+selectGroup =

428+ select

429+ ( param @1 `as` #mp_id

430+ :* param @2 `as` #first_name

431+ :* param @3 `as` #last_name

432+ :* #groupp ! #groupp_id `as` #mp_group

433+ )

434+ ( from (table #groupp)

435+ & where_ ( #groupp ! #name .== param @4 )

436+ )

437+```

438+

439+- The first three columns are constant defined through our params;

440+

441+- ... we alias the column name using `as`...

442+

443+- ... and when we need the result from the table we use the `#table ! #column` syntax.

444+

445+- We'll go back to the "from" block later.

446+

447+---

448+

449+# Dealing with the connection context

450+

451+- Queries are runned in a connection context:

452+

453+ * When dealing with a single-connection context, use the type `PQ`.

454+

455+ * When dealing with a pool of connection, use the type `PoolPQ`.

456+

457+- Or get rid of the context and use `mtl` style, with the typeclass `MonadPQ`.

458+

459+- We'll use that to demonstrate how to actually run our queries.

460+

461+---

462+

463+# Inserting a whole group

464+

465+```haskell

466+insertGroup :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()

467+insertGroup g@(Group name _) = do

468+ uuid' <- liftBase nextRandom

469+ void $ manipulateParams groupInsertion (uuid', name)

470+ insertMps g

471+```

472+

473+- Remember that we defined a group as a name and a list of MPs.

474+

475+- We are in `MonadBaseControl`, so we cannot use `liftIO`, we need `liftBase`.

476+

477+- To perform a simple insertion, use `manipulateParams`. It takes into parameter

478+instances of `ToParam`, but you will typically use tuples or Generic-SOP.

479+

480+---

481+

482+# Inserting a bunch of MPs

483+

484+```haskell

485+insertMps :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()

486+insertMps (Group groupName mps) =

487+ let tuplify Mp{..} = (, firstName, lastName, groupName) <$> nextRandom

488+ params = traverse tuplify mps

489+ in void $ liftBase params >>= traversePrepared mpInsertion

490+```

491+

492+- This time, we want to do a `preparedStatement`. We'll use `traversePrepare`

493+which behaves like `manipulateParams`, but expect a list of `ToParam`

494+instances.

495+

496+- We build our tuple manually again, mostly because we want to generate UUID on

497+the fly and we don't want to have them in our model.

498+

499+---

500+

501+# Inserting a whole parliament

502+

503+```haskell

504+insertParliament ::

505+ (MonadPQ Schema m, MonadBaseControl IO m) => Parliament -> m ()

506+insertParliament = traverse_ insertGroup

507+```

508+

509+- That's simple enough !

510+

511+- If we want to be a bit safer, though, we can wrap this call in a

512+`transactionally_` function, which will put all that in a transaction.

513+

514+---

515+

516+![Very simple](https://media1.tenor.com/images/0188c63209aced59f1583e1ca94e509e/tenor.gif?itemid=3550689)

517+

518+

519+---

520+

521+# Part III. Selects

522+

523+---

524+

525+# Composable queries

526+

527+- Building basic queries is easy, and is well documented.

528+

529+- However, the real interest of a tool like Squeal is in DRYness, and the documentation is still lacking in "how-to" related to composability.

530+

531+- I'll build an example showing how column selections and from clause can be factorized.

532+

533+- We want to write two queries:

534+

535+ * One to get all members of a specific group.

536+

537+ * One to get all the parliament.

538+

539+---

540+

541+# Decomposing a `Query`

542+

543+- A query typically stars with `select` (variants are available).

544+

545+- It then takes:

546+

547+ * A heterogenous list of fields with a scary signature;

548+

549+ * A virtual table (the from clause and filter clauses), called a `TableExpression`.

550+

551+- And return fields. Ours will look like this:

552+

553+```haskell

554+type GroupRowResult =

555+ '[ "groupName" ::: 'NotNull 'PGtext

556+ , "firstName" ::: 'NotNull 'PGtext

557+ , "lastName" ::: 'NotNull 'PGtext ]

558+```

559+

560+---

561+

562+# The Table Expression

563+

564+- It necessarily contains a `fromClause` (table, view or subquery, plus optional joins).

565+

566+- You can add where, groups, "HAVING" clause, order, etc.

567+

568+- `from` creates a basic `TableExpression` that you extend through various function to add clauses.

569+

570+- For our queries, we will share a common `FromClause`.

571+

572+---

573+

574+# The From Clause

575+

576+```

577+FromClause schema params from

578+```

579+

580+- We need Schema, input parameters and a `FromType` giving the available fields of the expression.

581+

582+- In our case, we'll join the table `mp` and the table `groupp`, meaning the `from` will be all fields of these tables.

583+

584+- We can use `TableToRow` to be more DRY:

585+

586+```haskell

587+type BaseParliamentSelection =

588+ '[ "g" ::: TableToRow GroupCols

589+ , "m" ::: TableToRow MpCols ]

590+```

591+

592+> _note_ We've also put everything with table aliases: "g" and "m".

593+

594+---

595+

596+# Writing our from clause

597+

598+```haskell

599+baseParliamentTables ::

600+ FromClause Schema (param :: [NullityType]) BaseParliamentSelection

601+baseParliamentTables =

602+ table

603+ (#groupp `as` #g)

604+ & innerJoin

605+ (table (#mp `as` #m))

606+ (#m ! #mp_group .== #g ! #groupp_id)

607+```

608+

609+- When picking "from" something, you need to specify the type with a function: `table` for a table, `view` for a view, etc.

610+

611+- All joins are available. `innerJoin` is the most basic one. It takes the joined table and the joining condition.

612+

613+- We have to specifiy the type of `param` (current limitation of the lib), even though _any_ params will be compatible with this, so we can plug `where` clauses depending on params should we need to !

614+

615+---

616+

617+# Typing the common selection

618+

619+- Both our querie will need the same fields. This has to be factorized too.

620+

621+- The scary signature of selection fields:

622+

623+```haskell

624+NP (Aliased (Expression schema from grouping params)) cols

625+```

626+

627+- `NP` is for heterogenous lists ("n-ary product").

628+

629+- `from` is the virtual table type, so our `BaseParliamentSelection`.

630+

631+- `grouping` is there to make a distinction between aggregated / unaggregated queries.

632+

633+- And finally, cols is the return type.

634+

635+---

636+

637+# Our common selection

638+

639+```haskell

640+groupSelection ::

641+ NP (Aliased (Expression Schema BaseParliamentSelection 'Ungrouped param))

642+ GroupRowResult

643+groupSelection =

644+ #g ! #name `as` #groupName

645+ :* #m ! #first_name `as` #firstName

646+ :* #m ! #last_name `as` #lastName

647+```

648+

649+- I hope you like big signatures.

650+

651+- But it's what let GHC checks that all alias and columns are available.

652+

653+- And that you're returning what you really intend to return.

654+

655+---

656+

657+# Putting it all together

658+

659+```haskell

660+selectParliament :: Query Schema '[] GroupRowResult

661+selectParliament =

662+ select groupSelection (from baseParliamentTables)

663+```

664+

665+```haskell

666+selectGroupMembers :: Query Schema '[ 'NotNull 'PGtext] GroupRowResult

667+selectGroupMembers =

668+ select groupSelection

669+ (from baseParliamentTables

670+ & where_ (#g ! #name .== param @1))

671+```

672+

673+- That is fairly DRY. And _entirely typesafe_.

674+

675+---

676+

677+# Actually fetching the data

678+

679+- We'll build an intermediary datatype representing our rows.

680+

681+- We'll make it match our row.

682+

683+- And we'll add generic-SOP so that we can build them from query results.

684+

685+```haskell

686+type GroupRowResult =

687+ '[ "groupName" ::: 'NotNull 'PGtext

688+ , "firstName" ::: 'NotNull 'PGtext

689+ , "lastName" ::: 'NotNull 'PGtext ]

690+```

691+

692+```haskell

693+data GroupRow =

694+ GroupRow { groupName :: Text

695+ , firstName :: Text

696+ , lastName :: Text }

697+ deriving (Generic)

698+

699+instance SOP.Generic GroupRow

700+instance SOP.HasDatatypeInfo GroupRow

701+```

702+

703+---

704+

705+# Aggregate result logic

706+

707+- We will get tabular, SQL data.

708+

709+- Our results will be `[GroupRow]`.

710+

711+- We'll build `Groups` from this:

712+

713+```haskell

714+buildGroup :: NE.NonEmpty GroupRow -> Group

715+buildGroup grs =

716+ let buildMP (GroupRow _ f l) = Mp f l

717+ name = groupName . NE.head $ grs

718+ members = NE.toList (buildMP <$> grs)

719+ in Group{..}

720+

721+rowToGroups :: [GroupRow] -> [Group]

722+rowToGroups =

723+ let grouped = fmap NE.fromList . L.groupBy ((==) `on` groupName)

724+ in fmap buildGroup . grouped

725+```

726+

727+---

728+

729+# Finally calling our queries

730+

731+- Query with params will use `runQueryParams`.

732+

733+- Query without params will use `runQuery`.

734+

735+- Result is inside a `MonadPQ` and of type `K` from generic-sop.

736+

737+- You get your actual result using `getRows`. Exemple:

738+

739+```haskell

740+getParliament :: (MonadPQ Schema m, MonadBaseControl IO m) => m [Group]

741+getParliament = do

742+ res <- runQuery selectParliament

743+ rows <- getRows res

744+ pure $ rowToGroups rows

745+```

746+

747+- In real life of course you'll write:

748+

749+```haskell

750+getParliament =

751+ rowToGroups <$> (runQuery selectParliament >>= getRows)

752+```

753+

754+---

755+

756+# Our query with params

757+

758+```haskell

759+getGroupMembers ::

760+ (MonadPQ Schema m, MonadBaseControl IO m) => Text -> m (Maybe Group)

761+getGroupMembers =

762+ listToMaybe . rowToGroups <$>

763+ (runQueryParams selectGroupMembers (Only t) >>= getRows)

764+```

765+

766+- And that's it.

767+

768+---

769+

770+![Eazy](https://media.tenor.com/images/8fc7c4077efe11b4a3a3b9ae4e643e87/tenor.gif)

771+

772+---

773+

774+# Conclusion

775+

776+---

777+

778+# Pros & Cons

779+

780+- Not everything is included: some cool stuff like array_agg and window functions are not available yet.

781+

782+- But development is _very_ active. `IN` clauses were missing but were added in the 4.0 released recently.

783+

784+- It's bleeding edge. You need latest LTS to be comfortable and psql >= 9.5.

785+

786+- It's Postgres-only but I would say that's a feature. Multi-DB tools are even more complex.

787+

788+- The author & maintainer is <3.

789+

790+- Typesafe. 'nuff said.

791+

792+---

793+

794+# Thank you !

stack.yaml+6−1

@@ -1,3 +1,8 @@

1−resolver: lts-11.15

1+resolver: nightly-2019-07-14

2packages:

3- squeal-postgresql

5+extra-deps:

6+- unliftio-pool-0.2.1.0

7+- github: morphismtech/free-categories

8+ commit: c0e555fbefb5c21619e532264c4dfeac556d0630