ea020d1...dev · squeal

git.iko.soy/squeal

on dev help sign in

.circleci/config.yml+3−2

since splitsnapshots

unifiedsplit

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

2jobs:

3 build:

4 docker:

5− - image: haskell:latest

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+126−119

@@ -44,6 +44,13 @@ composable and cover a large portion of SQL.

44* linear, invertible migrations

45* connection pools

46* transactions

47+* views

48+* array, composite and enumerated types

49+* json functions and operations

50+* multischema support

51+* correlated subqueries

52+* window functions

53+* text search

48## installation

55## installation

@@ -51,10 +58,16 @@ composable and cover a large portion of SQL.

52## testing

59## testing

54−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`.

56`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+

58## usage

71## usage

60Let's see an example!

73Let's see an example!

@@ -62,16 +75,15 @@ Let's see an example!

62First, we need some language extensions because Squeal uses modern GHC

75First, we need some language extensions because Squeal uses modern GHC

63features.

76features.

65−```haskell

78+```Haskell

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

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

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

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

68```

81```

70We'll need some imports.

83We'll need some imports.

72−```haskell

85+```Haskell

73−>>> import Control.Monad (void)

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

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

75>>> import Data.Int (Int32)

87>>> import Data.Int (Int32)

76>>> import Data.Text (Text)

88>>> import Data.Text (Text)

77>>> import Squeal.PostgreSQL

89>>> import Squeal.PostgreSQL

@@ -79,7 +91,7 @@ We'll need some imports.

80We'll use generics to easily convert between Haskell and PostgreSQL values.

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

82−```haskell

94+```Haskell

83>>> import qualified Generics.SOP as SOP

95>>> import qualified Generics.SOP as SOP

84>>> import qualified GHC.Generics as GHC

96>>> import qualified GHC.Generics as GHC

85```

97```

@@ -87,155 +99,152 @@ We'll use generics to easily convert between Haskell and PostgreSQL values.

87The first step is to define the schema of our database. This is where

99The first step is to define the schema of our database. This is where

88we use `DataKinds` and `TypeOperators`.

100we use `DataKinds` and `TypeOperators`.

101

90−```haskell

102+```Haskell

91>>> :{

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"] ]

92type Schema =

115type Schema =

93− '[ "users" :::

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

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

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

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

118+type Schemas = Public Schema

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

97− ]

98− , "emails" :::

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

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

101− ] :=>

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

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

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

105− ]

106− ]

107:}

119:}

108```

120```

109

121

110−Notice the use of type operators. `:::` is used

122+Notice the use of type operators.

123+

111−to pair an alias `Symbol` with either a `TableType` or a `ColumnType`.

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

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

126+operator.

127+

112−`:=>` is used to pair a `TableConstraint`s with a `ColumnsType`,

128+`:=>` is used to pair `TableConstraints` with a `ColumnsType`,

113yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,

129yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,

114−yielding a `ColumnType`.

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

115

131

116Next, 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

117−Squeal, a `Definition` is a `createTable`, `alterTable` or `dropTable`

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

118−command and has two type parameters, corresponding to the schema

134+has two type parameters, corresponding to the schema

119−before being run and the schema after. We can compose definitions using

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

120−`>>>`. Here and in the rest of our commands we make use of overloaded

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

121labels to refer to named tables and columns in our schema.

137labels to refer to named tables and columns in our schema.

122

138

123−```haskell

139+```Haskell

124>>> :{

140>>> :{

125let

141let

126− setup :: Definition '[] Schema

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

127− setup =

143+ setup =

128− createTable #users

144+ createTable #users

129− ( serial `As` #id :*

145+ ( serial `as` #id :*

130− (text & notNull) `As` #name :* Nil )

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

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

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

132− createTable #emails

148+ createTable #emails

133− ( serial `As` #id :*

149+ ( serial `as` #id :*

134− (int & notNull) `As` #user_id :*

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

135− (text & null') `As` #email :* Nil )

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

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

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

137− foreignKey #user_id #users #id

153+ foreignKey #user_id #users #id

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

154+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

139:}

155:}

140```

156```

141

157

142−We can easily see the generated SQL is unsuprising looking.

158+We can easily see the generated SQL is unsurprising looking.

143

159

144−```haskell

160+```Haskell

145−>>> renderDefinition setup

161+>>> printSQL setup

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

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

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

147```

164```

148

165

149Notice that `setup` starts with an empty schema `'[]` and produces `Schema`.

166Notice that `setup` starts with an empty schema `'[]` and produces `Schema`.

150In our `createTable` commands we included `TableConstraint`s to define

167In our `createTable` commands we included `TableConstraint`s to define

151−primary and foreign keys, making them somewhat complex. Our tear down

168+primary and foreign keys, making them somewhat complex. Our `teardown`

152`Definition` is simpler.

169`Definition` is simpler.

153

170

154−```haskell

171+```Haskell

155>>> :{

172>>> :{

156let

173let

157− teardown :: Definition Schema '[]

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

158 teardown = dropTable #emails >>> dropTable #users

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

159:}

176:}

177+

160−>>> renderDefinition teardown

178+>>> printSQL teardown

161−"DROP TABLE emails; DROP TABLE users;"

179+DROP TABLE "emails";

180+DROP TABLE "users";

181+```

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

162```

190```

163

191

164−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.

165−A `Manipulation` is an `insertRow` (or other inserts), `update`

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

166−or `deleteFrom` command and

167−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

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

195+and an output row. When

169we 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`

170−field but not for the `id` field. Since it's optional, we can use a default

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

171value. 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

172need 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

173−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

174−of our inserts.

201+`with` statement.

175

202

176−```haskell

203+```Haskell

177>>> :{

204>>> :{

178let

205let

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

206+ insertUser :: Manipulation_ Schemas User ()

180− insertUser = insertRow #users

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

208+ where

209+ u = insertInto #users

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

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

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

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

212+ e = insertInto_ #emails $ Select

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

214+ (from (common #u))

183:}

215:}

184−>>> :{

216+

185−let

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

187− insertEmail = insertRow #emails

188− ( Default `As` #id :*

189− Set (param @1) `As` #user_id :*

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

191− OnConflictDoNothing (Returning Nil)

192−:}

193−>>> renderManipulation insertUser

217+>>> printSQL insertUser

194−"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"

195−>>> renderManipulation insertEmail

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

197```

219```

198

220

199−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

200interested in the ids here, just the usernames and email addresses. We

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

201−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

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

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

203

225

204−```haskell

226+```Haskell

205>>> :{

227>>> :{

206let

228let

207− getUsers :: Query Schema '[]

229+ getUsers :: Query_ Schemas () User

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

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

210− getUsers = select

230+ getUsers = select_

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

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

212− ( from (table (#users `As` #u)

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

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

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

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

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

215:}

235:}

216−>>> renderQuery getUsers

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

218−```

219−

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

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

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

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

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

225

236

226−```haskell

237+>>> printSQL getUsers

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

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

228−>>> instance SOP.Generic User

229−>>> instance SOP.HasDatatypeInfo User

230```

239```

231

240

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

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

233

242

234−```haskell

243+```Haskell

235>>> :{

244>>> :{

236let

245let

237 users :: [User]

246 users :: [User]

238− users =

247+ users =

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

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

240 , User "Bob" Nothing

249 , User "Bob" Nothing

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

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

@@ -251,23 +260,21 @@ the changing schema information through by using the indexed `PQ` monad

251transformer and when the schema doesn't change we can use `Monad` and

260transformer and when the schema doesn't change we can use `Monad` and

252`MonadPQ` functionality.

261`MonadPQ` functionality.

253

262

254−```haskell

263+```Haskell

255>>> :{

264>>> :{

256let

265let

257− session :: PQ Schema Schema IO ()

266+ session :: PQ Schemas Schemas IO ()

258 session = do

267 session = do

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

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

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

268+ _ <- traversePrepared_ insertUser users

262 usersResult <- runQuery getUsers

269 usersResult <- runQuery getUsers

263 usersRows <- getRows usersResult

270 usersRows <- getRows usersResult

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

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

265−:}

272+in

266−>>> :{

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

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

268− define setup

274+ define setup

269− & pqThen session

275+ & pqThen session

270− & pqThen (define teardown)

276+ & pqThen (define teardown)

271:}

277:}

272[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+-}

273```

280```

RELEASE NOTES.md+1077

@@ -1,5 +1,1082 @@

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+

840+### Version 0.3 - June 26, 2018

841+

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

843+To support these features, a new kind `SchemumType` was added.

844+

845+```Haskell

846+data SchemumType

847+ = Table TableType

848+ | View RelationType

849+ | Typedef PGType

850+```

851+

852+As a consequence, you will have to update your schema definitions like so:

853+

854+```Haskell

855+-- Squeal 0.2

856+type Schema =

857+ '[ "users" :::

858+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

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

860+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

861+ ]

862+ ]

863+

864+-- Squeal 0.3

865+type Schema =

866+ '[ "users" ::: 'Table (

867+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

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

869+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

870+ ])

871+ ]

872+```

873+

874+**Views**

875+

876+You can now create, drop, and query views.

877+

878+```Haskell

879+>>> :{

880+type ABC =

881+ ('[] :: TableConstraints) :=>

882+ '[ "a" ::: 'NoDef :=> 'Null 'PGint4

883+ , "b" ::: 'NoDef :=> 'Null 'PGint4

884+ , "c" ::: 'NoDef :=> 'Null 'PGint4

885+ ]

886+type BC =

887+ '[ "b" ::: 'Null 'PGint4

888+ , "c" ::: 'Null 'PGint4

889+ ]

890+:}

891+

892+>>> :{

893+let

894+ definition :: Definition '["abc" ::: 'Table ABC ] '["abc" ::: 'Table ABC, "bc" ::: 'View BC]

895+ definition = createView #bc (select (#b :* #c :* Nil) (from (table #abc)))

896+in printSQL definition

897+:}

898+CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";

899+

900+>>> :{

901+let

902+ definition :: Definition '["abc" ::: 'Table ABC, "bc" ::: 'View BC] '["abc" ::: 'Table ABC]

903+ definition = dropView #bc

904+in printSQL definition

905+:}

906+DROP VIEW "bc";

907+

908+>>> :{

909+let

910+ query :: Query '["abc" ::: 'Table ABC, "bc" ::: 'View BC] '[] BC

911+ query = selectStar (from (view #bc))

912+in printSQL query

913+:}

914+SELECT * FROM "bc" AS "bc"

915+```

916+

917+**Enumerated Types**

918+

919+PostgreSQL has a powerful type system. It even allows for user defined types.

920+For instance, you can define enumerated types which are data types that comprise

921+a static, ordered set of values. They are equivalent to Haskell algebraic data

922+types whose constructors are nullary. An example of an enum type might be the days of the week,

923+or a set of status values for a piece of data.

924+

925+Enumerated types are created using the `createTypeEnum` command, for example:

926+

927+```Haskell

928+>>> :{

929+let

930+ definition :: Definition '[] '["mood" ::: 'Typedef ('PGenum '["sad", "ok", "happy"])]

931+ definition = createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy" :* Nil)

932+:}

933+>>> printSQL definition

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

935+```

936+

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

938+

939+```Haskell

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

941+>>> instance SOP.Generic Schwarma

942+>>> instance SOP.HasDatatypeInfo Schwarma

943+

944+>>> :kind! EnumFrom Schwarma

945+EnumFrom Schwarma :: PGType

946+= 'PGenum '["Beef", "Lamb", "Chicken"]

947+

948+>>> :{

949+let

950+ definition :: Definition '[] '["schwarma" ::: 'Typedef (EnumFrom Schwarma)]

951+ definition = createTypeEnumFrom @Schwarma #schwarma

952+:}

953+>>> printSQL definition

954+CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');

955+```

956+

957+You can express values of an enum type using `label`, which is an overloaded method

958+of the `IsPGlabel` typeclass.

959+

960+```Haskell

961+>>> :{

962+let

963+ expression :: Expression sch rels grp params ('NotNull (EnumFrom Schwarma))

964+ expression = label @"Chicken"

965+in printSQL expression

966+:}

967+'Chicken'

968+```

969+

970+**Composite Types**

971+

972+In addition to enum types, you can define composite types.

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

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

975+

976+

977+`createTypeComposite` creates a composite type. The composite type is

978+specified by a list of attribute names and data types.

979+

980+```Haskell

981+>>> :{

982+let

983+ definition :: Definition '[] '["complex" ::: 'Typedef ('PGcomposite '["real" ::: 'PGfloat8, "imaginary" ::: 'PGfloat8])]

984+ definition = createTypeComposite #complex (float8 `As` #real :* float8 `As` #imaginary :* Nil)

985+:}

986+>>> printSQL definition

987+CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

988+```

989+

990+Composite types are almost equivalent to Haskell record types.

991+However, because of the potential presence of `NULL`

992+all the record fields must be `Maybe`s of basic types.

993+Composite types can be generated from a Haskell record type, for example:

994+

995+```Haskell

996+>>> data Complex = Complex {real :: Maybe Double, imaginary :: Maybe Double} deriving GHC.Generic

997+>>> instance SOP.Generic Complex

998+>>> instance SOP.HasDatatypeInfo Complex

999+

1000+>>> :kind! CompositeFrom Complex

1001+CompositeFrom Complex :: PGType

1002+= 'PGcomposite '['("real", 'PGfloat8), '("imaginary", 'PGfloat8)]

1003+

1004+>>> :{

1005+let

1006+ definition :: Definition '[] '["complex" ::: 'Typedef (CompositeFrom Complex)]

1007+ definition = createTypeCompositeFrom @Complex #complex

1008+in printSQL definition

1009+:}

1010+CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);

1011+```

1012+

1013+A row constructor is an expression that builds a row value

1014+(also called a composite value) using values for its member fields.

1015+

1016+```Haskell

1017+>>> :{

1018+let

1019+ i :: Expression '[] '[] 'Ungrouped '[] ('NotNull (CompositeFrom Complex))

1020+ i = row (0 `As` #real :* 1 `As` #imaginary :* Nil)

1021+:}

1022+>>> printSQL i

1023+ROW(0, 1)

1024+```

1025+

1026+You can also use `(&)` to apply a field label to a composite value.

1027+

1028+```Haskell

1029+>>> :{

1030+let

1031+ expr :: Expression '[] '[] 'Ungrouped '[] ('Null 'PGfloat8)

1032+ expr = i & #imaginary

1033+in printSQL expr

1034+:}

1035+(ROW(0, 1)).imaginary

1036+```

1037+

1038+Both composite and enum types can be automatically encoded from and decoded to their equivalent Haskell types.

1039+And they can be dropped.

1040+

1041+```Haskell

1042+>>> :{

1043+let

1044+ definition :: Definition '["mood" ::: 'Typedef ('PGenum '["sad", "ok", "happy"])] '[]

1045+ definition = dropType #mood

1046+:}

1047+>>> printSQL definition

1048+DROP TYPE "mood";

1049+```

1050+

1051+**Additional Changes**

1052+

1053+Squeal 0.3 also introduces a typeclass `HasAll` similar to `Has` but for a list of aliases.

1054+This makes it possible to clean up some unfortunately messy Squeal 0.2 definitions.

1055+

1056+```Haskell

1057+-- Squeal 0.2

1058+>>> unique (Column #a :* Column #b :* Nil)

1059+

1060+-- Squeal 0.3

1061+>>> unique (#a :* #b :* Nil)

1062+```

1063+

1064+Squeal 0.3 also adds `IsLabel` instances for `Aliased` expressions and tables as well as

1065+heterogeneous lists, allowing for some more economy of code.

1066+

1067+```Haskell

1068+-- Squeal 0.2 (or 0.3)

1069+>>> select (#a `As` #a :* Nil) (from (table (#t `As` #t)))

1070+

1071+-- Squeal 0.3

1072+>>> select #a (from (table #t))

1073+```

1074+

1075+Squeal 0.3 also fixes a bug that prevented joined queries on self-referencing tables.

1076+

1077+The above changes required major and minor changes to Squeal DSL functions.

1078+Please consult the documentation.

1079+

3### Version 0.2.1 - April 7, 2018

1080### Version 0.2.1 - April 7, 2018

1081

5This minor update fixes an issue where alias identifiers could conflict with

1082This minor update fixes an issue where alias identifiers could conflict with

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 & notNull) `As` #name :*

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

49− (vararray int2 & notNull) `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 & notNull) `As` #user_id :*

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

55− (text & null') `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+74−11

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

1name: squeal-postgresql

2−version: 0.2.1.0

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

@@ -22,52 +22,116 @@ 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

34 Squeal.PostgreSQL.Schema

62 Squeal.PostgreSQL.Schema

35 Squeal.PostgreSQL.Transaction

63 Squeal.PostgreSQL.Transaction

36 default-language: Haskell2010

64 default-language: Haskell2010

37− ghc-options: -Wall -fprint-explicit-kinds

65+ ghc-options: -Wall

38 build-depends:

66 build-depends:

39 aeson >= 1.2.4.0

67 aeson >= 1.2.4.0

40− , base >= 4.10.1.0 && < 5.0

68+ , base >= 4.11.1.0 && < 5.0

69+ , binary-parser >= 0.5.5

41 , bytestring >= 0.10.8.2

70 , bytestring >= 0.10.8.2

71+ , bytestring-strict-builder >= 0.4.5

42 , deepseq >= 1.4.3.0

72 , deepseq >= 1.4.3.0

73+ , free-categories >= 0.1.0.0

43− , generics-sop >= 0.3.2.0

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

44− , lifted-base >= 0.2.3.12

45 , mmorph >= 1.1.1

75 , mmorph >= 1.1.1

46− , monad-control >= 1.0.2.3

47 , mtl >= 2.2.2

76 , mtl >= 2.2.2

48 , network-ip >= 0.3.0.2

77 , network-ip >= 0.3.0.2

49 , postgresql-binary >= 0.12.1

78 , postgresql-binary >= 0.12.1

50 , postgresql-libpq >= 0.9.4.1

79 , postgresql-libpq >= 0.9.4.1

80+ , records-sop >= 0.1.0.0

51 , resource-pool >= 0.2.3.2

81 , resource-pool >= 0.2.3.2

52 , scientific >= 0.3.5.3

82 , scientific >= 0.3.5.3

53 , text >= 1.2.3.0

83 , text >= 1.2.3.0

54 , time >= 1.8.0.2

84 , time >= 1.8.0.2

55 , transformers >= 0.5.2.0

85 , transformers >= 0.5.2.0

56− , transformers-base >= 0.4.4

86+ , unliftio >= 0.2.10

87+ , unliftio-pool >= 0.2.1.0

57 , uuid-types >= 1.0.3

88 , uuid-types >= 1.0.3

58 , vector >= 0.12.0.1

89 , vector >= 0.12.0.1

60−test-suite squeal-postgresql-doctest

91+test-suite doctest

61 default-language: Haskell2010

92 default-language: Haskell2010

62 type: exitcode-stdio-1.0

93 type: exitcode-stdio-1.0

63 hs-source-dirs: test

94 hs-source-dirs: test

64 ghc-options: -Wall

95 ghc-options: -Wall

65− main-is: DocTest.hs

96+ main-is: Doc.hs

66 build-depends:

97 build-depends:

67 base >= 4.10.0.0

98 base >= 4.10.0.0

68 , doctest >= 0.11.4

99 , doctest >= 0.11.4

100+ , squeal-postgresql

101+

102+test-suite properties

103+ default-language: Haskell2010

104+ type: exitcode-stdio-1.0

105+ hs-source-dirs: test

106+ ghc-options: -Wall

107+ main-is: Property.hs

108+ build-depends:

109+ base >= 4.10.0.0

110+ , bytestring >= 0.10.8.2

111+ , hedgehog >= 1.0

112+ , mtl >= 2.2.2

113+ , scientific >= 0.3.5.3

114+ , squeal-postgresql

115+ , time >= 1.8.0.2

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

70−executable squeal-postgresql-example

134+executable example

71 default-language: Haskell2010

135 default-language: Haskell2010

72 hs-source-dirs: exe

136 hs-source-dirs: exe

73 ghc-options: -Wall

137 ghc-options: -Wall

@@ -80,5 +144,4 @@ executable squeal-postgresql-example

80 , squeal-postgresql

144 , squeal-postgresql

81 , text >= 1.2.2.2

145 , text >= 1.2.2.2

82 , transformers >= 0.5.2.0

146 , transformers >= 0.5.2.0

83− , transformers-base >= 0.4.4

84 , vector >= 0.12.0.1

147 , vector >= 0.12.0.1

squeal-postgresql/src/Squeal/PostgreSQL.hs+233−222

@@ -1,222 +1,233 @@

1+{-|

1−-- | Module: Squeal.PostgreSQL

2+Module: Squeal.PostgreSQL

2−-- Description: Squeel export module

3+Description: Squeal export module

3−-- Copyright: (c) Eitan Chatav, 2017

4+Copyright: (c) Eitan Chatav, 2019

4−-- Maintainer: eitan@morphism.tech

5+Maintainer: eitan@morphism.tech

5−-- Stability: experimental

6+Stability: experimental

6−--

7−-- Squeal is a deep embedding of [PostgreSQL](https://www.postgresql.org) in Haskell.

8+Squeal is a deep embedding of [PostgreSQL](https://www.postgresql.org) in Haskell.

8−-- Let's see an example!

9+Let's see an example!

9−--

10+

10−-- First, we need some language extensions because Squeal uses modern GHC

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

11−-- features.

12+features.

12−--

13+

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

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

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

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

15−--

16+

16−-- We'll need some imports.

17+We'll need some imports.

17−--

18+

18−-- >>> import Control.Monad (void)

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

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

20−-- >>> import Data.Int (Int32)

20+>>> import Data.Int (Int32)

21−-- >>> import Data.Text (Text)

21+>>> import Data.Text (Text)

22−-- >>> import Squeal.PostgreSQL

22+>>> import Squeal.PostgreSQL

23−--

23+

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

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

25−--

25+

26−-- >>> import qualified Generics.SOP as SOP

26+>>> import qualified Generics.SOP as SOP

27−-- >>> import qualified GHC.Generics as GHC

27+>>> import qualified GHC.Generics as GHC

28−--

28+

29−-- The first step is to define the schema of our database. This is where

29+The first step is to define the schema of our database. This is where

30−-- we use @DataKinds@ and @TypeOperators@.

30+we use @DataKinds@ and @TypeOperators@.

31−--

31+

32−-- >>> :{

32+>>> :{

33−-- type Schema =

33+type UsersColumns =

34−-- '[ "users" ::: 'Table (

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

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

35−-- '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

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

37+type EmailsColumns =

36−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

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

37−-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext

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

38−-- ])

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

39−-- , "emails" ::: 'Table (

41+type EmailsConstraints =

40−-- '[ "pk_emails" ::: 'PrimaryKey '["id"]

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

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

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

42−-- ] :=>

44+type Schema =

43−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

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

44−-- , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

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

45−-- , "email" ::: 'NoDef :=> 'Null 'PGtext

47+type Schemas = Public Schema

46−-- ])

47−-- ]

48−-- :}

48+:}

49−--

49+

50−-- Notice the use of type operators. `:::` is used

50+Notice the use of type operators.

51+

51−-- to pair an alias `Symbol` with either a `TableType` or a `ColumnType`.

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

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

54+operator.

55+

52−-- `:=>` is used to pair a `TableConstraint`s with a `ColumnsType`,

56+`:=>` is used to pair `TableConstraints` with a `ColumnsType`,

53−-- yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,

57+yielding a `TableType`, or to pair a `ColumnConstraint` with a `NullityType`,

54−-- yielding a `ColumnType`.

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

55−--

59+

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

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

57−-- Squeal, a `Definition` is a `createTable`, `alterTable` or `dropTable`

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

58−-- command and has two type parameters, corresponding to the schema

62+has two type parameters, corresponding to the schema

59−-- before being run and the schema after. We can compose definitions using

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

60−-- `>>>`. Here and in the rest of our commands we make use of overloaded

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

61−-- labels to refer to named tables and columns in our schema.

65+labels to refer to named tables and columns in our schema.

62−--

66+

63−-- >>> :{

67+>>> :{

64−-- let

68+let

65−-- setup :: Definition '[] Schema

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

66−-- setup =

70+ setup =

67−-- createTable #users

71+ createTable #users

68−-- ( serial `As` #id :*

72+ ( serial `as` #id :*

69−-- (text & notNull) `As` #name :* Nil )

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

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

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

71−-- createTable #emails

75+ createTable #emails

72−-- ( serial `As` #id :*

76+ ( serial `as` #id :*

73−-- (int & notNull) `As` #user_id :*

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

74−-- (text & null') `As` #email :* Nil )

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

75−-- ( primaryKey #id `As` #pk_emails :*

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

76−-- foreignKey #user_id #users #id

80+ foreignKey #user_id #users #id

77−-- OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

81+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

78−-- :}

82+:}

79−--

83+

80−-- We can easily see the generated SQL is unsuprising looking.

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

81−--

85+

82−-- >>> renderDefinition setup

86+>>> printSQL setup

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

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

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

84−--

89+

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

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

86−-- In our `createTable` commands we included `TableConstraint`s to define

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

87−-- primary and foreign keys, making them somewhat complex. Our tear down

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

88−-- `Definition` is simpler.

93+`Definition` is simpler.

89−--

94+

90−-- >>> :{

95+>>> :{

91−-- let

96+let

92−-- teardown :: Definition Schema '[]

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

93−-- teardown = dropTable #emails >>> dropTable #users

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

94−-- :}

99+:}

95−--

100+

96−-- >>> renderDefinition teardown

101+>>> printSQL teardown

97−-- "DROP TABLE \"emails\"; DROP TABLE \"users\";"

102+DROP TABLE "emails";

98−--

103+DROP TABLE "users";

104+

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

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

107+

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

109+>>> instance SOP.Generic User

110+>>> instance SOP.HasDatatypeInfo User

111+

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

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

100−-- A `Manipulation` is an `insertRow` (or other inserts), `update`

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

101−-- or `deleteFrom` command and

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

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

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

115+and an output row. When

104−-- we insert into the users table, we will need a parameter for the @name@

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

105−-- field but not for the @id@ field. Since it's optional, we can use a default

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

106−-- value. However, since the emails table refers to the users table, we will

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

107−-- need to retrieve the user id that the insert generates and insert it into

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

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

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

109−-- of our inserts.

121+`with` statement.

110−--

122+

111−-- >>> :{

123+>>> :{

112−-- let

124+let

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

125+ insertUser :: Manipulation_ Schemas User ()

114−-- insertUser = insertRow #users

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

127+ where

128+ u = insertInto #users

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

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

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

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

117−-- :}

131+ e = insertInto_ #emails $ Select

118−--

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

119−-- >>> :{

133+ (from (common #u))

120−-- let

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

122−-- insertEmail = insertRow #emails

123−-- ( Default `As` #id :*

124−-- Set (param @1) `As` #user_id :*

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

126−-- OnConflictDoNothing (Returning Nil)

127−-- :}

134+:}

128−--

135+

129−-- >>> renderManipulation insertUser

136+>>> printSQL insertUser

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

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

131−-- >>> renderManipulation insertEmail

138+

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

133−--

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

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

135−-- interested in the ids here, just the usernames and email addresses. We

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

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

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

137−-- `Manipulation` with the same kind of type parameters.

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

138−--

143+

139−-- >>> :{

144+>>> :{

140−-- let

145+let

141−-- getUsers :: Query Schema '[]

146+ getUsers :: Query_ Schemas () User

142−-- '[ "userName" ::: 'NotNull 'PGtext

143−-- , "userEmail" ::: 'Null 'PGtext ]

144−-- getUsers = select

147+ getUsers = select_

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

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

146−-- ( from (table (#users `As` #u)

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

147−-- & innerJoin (table (#emails `As` #e))

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

148−-- (#u ! #id .== #e ! #user_id)) )

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

149−-- :}

152+:}

150−--

153+

151−-- >>> renderQuery getUsers

154+>>> printSQL getUsers

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

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

153−--

156+

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

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

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

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

158−-- @User@ type match the column names of @getUsers@.

159−--

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

161−-- >>> instance SOP.Generic User

162−-- >>> instance SOP.HasDatatypeInfo User

163−--

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

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

165−--

158+

166−-- >>> :{

159+>>> :{

167−-- let

160+let

168−-- users :: [User]

161+ users :: [User]

169−-- users =

162+ users =

170−-- [ User "Alice" (Just "alice@gmail.com")

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

171−-- , User "Bob" Nothing

164+ , User "Bob" Nothing

172−-- , User "Carole" (Just "carole@hotmail.com")

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

173−-- ]

166+ ]

174−-- :}

167+:}

175−--

168+

176−-- Now we can put together all the pieces into a program. The program

169+Now we can put together all the pieces into a program. The program

177−-- connects to the database, sets up the schema, inserts the user data

170+connects to the database, sets up the schema, inserts the user data

178−-- (using prepared statements as an optimization), queries the user

171+(using prepared statements as an optimization), queries the user

179−-- data and prints it out and finally closes the connection. We can thread

172+data and prints it out and finally closes the connection. We can thread

180−-- the changing schema information through by using the indexed `PQ` monad

173+the changing schema information through by using the indexed `PQ` monad

181−-- transformer and when the schema doesn't change we can use `Monad` and

174+transformer and when the schema doesn't change we can use `Monad` and

182−-- `MonadPQ` functionality.

175+`MonadPQ` functionality.

183−--

176+

184−-- >>> :{

177+>>> :{

185−-- let

178+let

186−-- session :: PQ Schema Schema IO ()

179+ session :: PQ Schemas Schemas IO ()

187−-- session = do

180+ session = do

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

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

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

181+ _ <- traversePrepared_ insertUser users

191−-- usersResult <- runQuery getUsers

182+ usersResult <- runQuery getUsers

192−-- usersRows <- getRows usersResult

183+ usersRows <- getRows usersResult

193−-- liftBase $ print (usersRows :: [User])

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

194−-- :}

185+in

195−--

196−-- >>> :{

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

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

198−-- define setup

187+ define setup

199−-- & pqThen session

188+ & pqThen session

200−-- & pqThen (define teardown)

189+ & pqThen (define teardown)

201−-- :}

190+:}

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

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

203−

192+-}

204−module Squeal.PostgreSQL

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

194+

205− ( module Squeal.PostgreSQL.Binary

195+import Squeal.PostgreSQL.Alias as X

196+import Squeal.PostgreSQL.Binary as X

197+import Squeal.PostgreSQL.Definition as X

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

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

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

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

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

206− , module Squeal.PostgreSQL.Definition

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

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

207− , module Squeal.PostgreSQL.Expression

205+import Squeal.PostgreSQL.Expression as X

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

208− , module Squeal.PostgreSQL.Manipulation

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

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

209− , module Squeal.PostgreSQL.PQ

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

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

210− , module Squeal.PostgreSQL.Query

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

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

211− , module Squeal.PostgreSQL.Schema

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

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

212− , module Squeal.PostgreSQL.Transaction

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

213− ) where

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

214−

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

215−import Squeal.PostgreSQL.Binary

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

216−import Squeal.PostgreSQL.Definition

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

217−import Squeal.PostgreSQL.Expression

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

218−import Squeal.PostgreSQL.Manipulation

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

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

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

224+import Squeal.PostgreSQL.List as X

225+import Squeal.PostgreSQL.Manipulation as X

226+import Squeal.PostgreSQL.Migration as X

219−import Squeal.PostgreSQL.PQ

227+import Squeal.PostgreSQL.PG as X

228+import Squeal.PostgreSQL.Pool as X

229+import Squeal.PostgreSQL.PQ as X

220−import Squeal.PostgreSQL.Query

230+import Squeal.PostgreSQL.Query as X

221−import Squeal.PostgreSQL.Schema

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

232+import Squeal.PostgreSQL.Schema as X

222−import Squeal.PostgreSQL.Transaction

233+import Squeal.PostgreSQL.Transaction as X

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

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

1+{-|

2+Module: Squeal.PostgreSQL.Alias

3+Description: Aliases

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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

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

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

11+-}

12+

13+{-# LANGUAGE

14+ AllowAmbiguousTypes

15+ , ConstraintKinds

16+ , DeriveAnyClass

17+ , DeriveGeneric

18+ , FlexibleContexts

19+ , FlexibleInstances

20+ , FunctionalDependencies

21+ , GADTs

22+ , LambdaCase

23+ , OverloadedStrings

24+ , QuantifiedConstraints

25+ , RankNTypes

26+ , ScopedTypeVariables

27+ , StandaloneDeriving

28+ , TypeApplications

29+ , TypeFamilyDependencies

30+ , TypeInType

31+ , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

34+#-}

35+

36+module Squeal.PostgreSQL.Alias

37+ ( (:::)

38+ , Alias (..)

39+ , IsLabel (..)

40+ , Aliased (As)

41+ , Aliasable (as)

42+ , renderAliased

43+ , Has

44+ , HasUnique

45+ , HasAll

46+ , HasIn

47+ , QualifiedAlias (..)

48+ , IsQualified (..)

49+ -- * Grouping

50+ , Grouping (..)

51+ , GroupedBy

52+ ) where

53+

54+import Control.DeepSeq

55+import Data.ByteString (ByteString)

56+import Data.String (fromString)

57+import GHC.OverloadedLabels

58+import GHC.TypeLits

59+

60+import qualified Generics.SOP as SOP

61+import qualified GHC.Generics as GHC

62+

63+import Squeal.PostgreSQL.List

64+import Squeal.PostgreSQL.Render

65+

66+-- $setup

67+-- >>> import Squeal.PostgreSQL

68+

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

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

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

72+infixr 6 :::

73+

74+

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

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

77+-- for typesafe aggregation

78+data Grouping

79+ = Ungrouped -- ^ no aggregation permitted

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

81+

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

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

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

85+-}

86+class (KnownSymbol table, KnownSymbol column)

87+ => GroupedBy table column bys where

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

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

90+instance {-# OVERLAPPABLE #-}

91+ ( KnownSymbol table

92+ , KnownSymbol column

93+ , GroupedBy table column bys

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

95+

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

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

98+--

99+-- >>> :set -XOverloadedLabels

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

101+-- Alias

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

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

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

105+ fromLabel = Alias

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

107+ fromLabel = fromLabel SOP.:* Nil

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

109+-- "jimbob"

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

111+ renderSQL = doubleQuoted . fromString . symbolVal

112+

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

114+-- "jimbob", "kandi"

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

116+ renderSQL

117+ = commaSeparated

118+ . SOP.hcollapse

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

120+

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

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

123+--

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

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

126+data Aliased expression aliased where

127+ As

128+ :: KnownSymbol alias

129+ => expression ty

130+ -> Alias alias

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

132+deriving instance Show (expression ty)

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

134+deriving instance Eq (expression ty)

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

136+deriving instance Ord (expression ty)

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

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

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

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

141+

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

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

144+class KnownSymbol alias => Aliasable alias expression aliased

145+ | aliased -> expression

146+ , aliased -> alias

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

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

149+ (expression ty)

150+ (Aliased expression aliased)

151+ where

152+ as = As

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

154+ (expression ty)

155+ (NP (Aliased expression) tys)

156+ where

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

158+

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

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

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

162+renderAliased

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

164+ -> Aliased expression aliased

165+ -> ByteString

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

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

168+

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

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

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

172+

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

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

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

176+class KnownSymbol alias =>

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

178+ | alias fields -> field where

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

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

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

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

183+

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

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

186+choose which subfields to update.

187+-}

188+class HasIn fields field where

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

190+

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

192+-- a list of @subfields@.

193+class

194+ ( SOP.All KnownSymbol aliases

195+ ) => HasAll

196+ (aliases :: [Symbol])

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

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

199+ | aliases fields -> subfields where

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

201+instance {-# OVERLAPPABLE #-}

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

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

204+

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

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

207+-- by a table alias.

208+class IsQualified table column expression where

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

210+ infixl 9 !

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

212+

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

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

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

216+a qualifier of @public@ is provided.

217+

218+>>> :{

219+let

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

221+ alias1 = #sch ! #tab

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

223+ alias2 = #vw

224+in printSQL alias1 >> printSQL alias2

225+:}

226+"sch"."tab"

227+"vw"

228+-}

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

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

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

232+ _!_ = QualifiedAlias

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

234+ fromLabel = QualifiedAlias

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

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

237+ _!_ = QualifiedAlias `As` Alias

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

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

240+ fromLabel = QualifiedAlias `As` Alias

241+

242+instance (KnownSymbol q, KnownSymbol a)

243+ => RenderSQL (QualifiedAlias q a) where

244+ renderSQL _ =

245+ let

246+ qualifier = renderSQL (Alias @q)

247+ alias = renderSQL (Alias @a)

248+ in

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

squeal-postgresql/src/Squeal/PostgreSQL/Binary.hs+690−119

@@ -5,22 +5,192 @@ Copyright: (c) Eitan Chatav, 2017

5Maintainer: eitan@morphism.tech

6Stability: experimental

8−Binary encoding and decoding between Haskell and PostgreSQL types.

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

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

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

12+to encode Haskell values into statement parameters.

13+

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

15+

16+>>> import Data.Int (Int16)

17+>>> import Data.Text (Text)

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

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

20+>>> import Squeal.PostgreSQL

21+

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

23+round trip query.

24+

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

26+>>> instance Generic Row

27+>>> instance HasDatatypeInfo Row

28+>>> :{

29+let

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

31+ roundTrip = values_ $

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

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

34+ parameter @3 bool `as` #col3

35+:}

36+

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

38+the input and output should be equal.

39+

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

41+>>> :{

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

43+ result <- runQueryParams roundTrip input

44+ Just output <- firstRow result

45+ liftIO . print $ input == output

46+:}

47+True

48+

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

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

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

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

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

54+create multi-dimensional fixed length arrays.

55+

56+>>> :{

57+data Row = Row

58+ { col1 :: VarArray (Vector Int16)

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

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

61+ } deriving (Eq, GHC.Generic)

62+:}

63+

64+>>> instance Generic Row

65+>>> instance HasDatatypeInfo Row

66+

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

68+

69+>>> :{

70+let

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

72+ roundTrip = values_ $

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

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

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

76+:}

77+

78+>>> :set -XOverloadedLists

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

80+>>> :{

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

82+ result <- runQueryParams roundTrip input

83+ Just output <- firstRow result

84+ liftIO . print $ input == output

85+:}

86+True

87+

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

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

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

91+or a set of status values for a piece of data.

92+

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

94+>>> instance Generic Schwarma

95+>>> instance HasDatatypeInfo Schwarma

96+

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

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

99+

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

101+>>> instance Generic Person

102+>>> instance HasDatatypeInfo Person

103+>>> instance Aeson.FromJSON Person

104+>>> instance Aeson.ToJSON Person

105+

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

107+

108+>>> :{

109+type Schema =

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

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

112+ ]

113+:}

114+

115+>>> :{

116+let

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

118+ setup =

119+ createTypeEnumFrom @Schwarma #schwarma >>>

120+ createTypeCompositeFrom @Person #person

121+:}

122+

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

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

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

126+

127+>>> :{

128+data Row = Row

129+ { schwarma :: Enumerated Schwarma

130+ , person1 :: Composite Person

131+ , person2 :: Json Person

132+ } deriving (Eq, GHC.Generic)

133+:}

134+

135+>>> instance Generic Row

136+>>> instance HasDatatypeInfo Row

137+>>> :{

138+let

139+ input = Row

140+ (Enumerated Chicken)

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

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

143+:}

144+

145+Once again, define a round trip query.

146+

147+>>> :{

148+let

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

150+ roundTrip = values_ $

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

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

153+ parameter @3 json `as` #person2

154+:}

155+

156+Finally, we can drop our type definitions.

157+

158+>>> :{

159+let

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

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

162+:}

163+

164+Now let's run it.

165+

166+>>> :{

167+let

168+ session = do

169+ result <- runQueryParams roundTrip input

170+ Just output <- firstRow result

171+ liftIO . print $ input == output

172+in

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

174+ define setup

175+ & pqThen session

176+ & pqThen (define teardown)

177+:}

178+True

9-}

179-}

180

11{-# LANGUAGE

181{-# LANGUAGE

12− ConstraintKinds

182+ AllowAmbiguousTypes

13− , DataKinds

14− , DefaultSignatures

15 , DeriveFoldable

183 , DeriveFoldable

16 , DeriveFunctor

184 , DeriveFunctor

17 , DeriveGeneric

185 , DeriveGeneric

18 , DeriveTraversable

186 , DeriveTraversable

187+ , DefaultSignatures

19 , FlexibleContexts

188 , FlexibleContexts

20 , FlexibleInstances

189 , FlexibleInstances

190+ , FunctionalDependencies

21 , GADTs

191 , GADTs

22 , LambdaCase

192 , LambdaCase

23− , KindSignatures

193+ , OverloadedStrings

24 , MultiParamTypeClasses

194 , MultiParamTypeClasses

25 , ScopedTypeVariables

195 , ScopedTypeVariables

26 , TypeApplications

196 , TypeApplications

@@ -28,22 +198,33 @@ Binary encoding and decoding between Haskell and PostgreSQL types.

28 , TypeInType

198 , TypeInType

29 , TypeOperators

199 , TypeOperators

30 , UndecidableInstances

200 , UndecidableInstances

201+ , UndecidableSuperClasses

31#-}

202#-}

203

33module Squeal.PostgreSQL.Binary

204module Squeal.PostgreSQL.Binary

34 ( -- * Encoding

205 ( -- * Encoding

35 ToParam (..)

206 ToParam (..)

36− , ToColumnParam (..)

37 , ToParams (..)

207 , ToParams (..)

208+ , ToNullityParam (..)

209+ , ToField (..)

210+ , ToFixArray (..)

38 -- * Decoding

211 -- * Decoding

39 , FromValue (..)

212 , FromValue (..)

40− , FromColumnValue (..)

41 , FromRow (..)

213 , FromRow (..)

214+ , FromField (..)

215+ , FromFixArray (..)

42 -- * Only

216 -- * Only

43 , Only (..)

217 , Only (..)

218+ -- * Oid

219+ , OidOf (..)

220+ , OidOfParam (..)

221+ , OidOfField (..)

44 ) where

222 ) where

223

46−import Data.Aeson hiding (Null)

224+import BinaryParser

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

226+import Control.Arrow (left)

227+import Control.Monad

47import Data.Int

228import Data.Int

48import Data.Kind

229import Data.Kind

49import Data.Scientific

230import Data.Scientific

@@ -51,19 +232,28 @@ import Data.Time

51import Data.UUID.Types

232import Data.UUID.Types

52import Data.Vector (Vector)

233import Data.Vector (Vector)

53import Data.Word

234import Data.Word

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

54import Generics.SOP

236import Generics.SOP

237+import Generics.SOP.Record

55import GHC.TypeLits

238import GHC.TypeLits

56import Network.IP.Addr

239import Network.IP.Addr

240

58−import qualified Data.ByteString.Lazy as Lazy

241+import qualified Data.Aeson as Aeson

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

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

59−import qualified Data.ByteString as Strict hiding (unpack)

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

60−import qualified Data.Text.Lazy as Lazy

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

61−import qualified Data.Text as Strict

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

247+import qualified Data.Text as Strict.Text

62import qualified Data.Vector as Vector

248import qualified Data.Vector as Vector

249+import qualified Database.PostgreSQL.LibPQ as LibPQ

63import qualified GHC.Generics as GHC

250import qualified GHC.Generics as GHC

64import qualified PostgreSQL.Binary.Decoding as Decoding

251import qualified PostgreSQL.Binary.Decoding as Decoding

65import qualified PostgreSQL.Binary.Encoding as Encoding

252import qualified PostgreSQL.Binary.Encoding as Encoding

253

254+import Squeal.PostgreSQL.Alias

255+import Squeal.PostgreSQL.List

256+import Squeal.PostgreSQL.PG

67import Squeal.PostgreSQL.Schema

257import Squeal.PostgreSQL.Schema

258

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

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

@@ -87,19 +277,20 @@ class ToParam (x :: Type) (pg :: PGType) where

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

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

88instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

278instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

89instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

279instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

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

91instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

280instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

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

93instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

281instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

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

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

95instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

283instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

96instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

284instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

97instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric

285instance ToParam Scientific 'PGnumeric where toParam = K . Encoding.numeric

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

98instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

287instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

99instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

288instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

100instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

289instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

101instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict

290instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict

102instance ToParam Lazy.Text 'PGtext where toParam = K . Encoding.text_lazy

291instance ToParam Lazy.Text 'PGtext where toParam = K . Encoding.text_lazy

292+instance ToParam String 'PGtext where

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

103instance ToParam Strict.ByteString 'PGbytea where

294instance ToParam Strict.ByteString 'PGbytea where

104 toParam = K . Encoding.bytea_strict

295 toParam = K . Encoding.bytea_strict

105instance ToParam Lazy.ByteString 'PGbytea where

296instance ToParam Lazy.ByteString 'PGbytea where

@@ -113,34 +304,256 @@ instance ToParam LocalTime 'PGtimestamp where

113instance ToParam UTCTime 'PGtimestamptz where

304instance ToParam UTCTime 'PGtimestamptz where

114 toParam = K . Encoding.timestamptz_int

305 toParam = K . Encoding.timestamptz_int

115instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int

306instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int

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

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

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

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

118−instance (HasOid pg, ToParam x pg)

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

310+ toParam = K . Encoding.json_bytes

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

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

313+ toParam = K . Encoding.jsonb_bytes

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

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

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

317+ toParam = K

318+ . Encoding.array_foldable

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

320+ . getVarArray

321+instance (ToParam x pg, OidOf pg)

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

323+ toParam = K

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

325+ . getVarArray

326+instance (ToParam x pg, OidOf pg)

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

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

328+ toParam = K

120− toParam = K . Encoding.nullableArray_vector

329+ . Encoding.nullableArray_vector

121− (oid @pg) (unK . toParam @x @pg)

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

122−

331+ . getVarArray

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

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

124−-- of a `Type` to a `ColumnType`, encoding `Maybe`s to `Null`s. You should

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

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

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

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

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

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

336+instance

128− -- K (Just "\NUL\NUL")

337+ ( IsEnumType x

129− --

338+ , HasDatatypeInfo x

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

339+ , LabelsPG x ~ labels

131− -- K (Just "\NUL\NUL")

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

132− --

341+ toParam =

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

342+ let

134− -- K Nothing

343+ gshowConstructor :: NP ConstructorInfo xss -> SOP I xss -> String

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

344+ gshowConstructor Nil _ = ""

345+ gshowConstructor (constructor :* _) (SOP (Z _)) =

346+ constructorName constructor

347+ gshowConstructor (_ :* constructors) (SOP (S xs)) =

348+ gshowConstructor constructors (SOP xs)

349+ in

350+ K . Encoding.text_strict

351+ . Strict.Text.pack

352+ . gshowConstructor (constructorInfo (datatypeInfo (Proxy @x)))

353+ . from

354+ . getEnumerated

355+instance

356+ ( SListI fields

357+ , IsRecord x xs

358+ , AllZip ToField xs fields

359+ , All OidOfField fields

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

361+ toParam =

362+ let

363+

364+ encoders = htrans (Proxy @ToField) toField

365+

366+ composite

367+ :: All OidOfField row

368+ => NP (K (Maybe Encoding.Encoding)) row

369+ -> K Encoding.Encoding ('PGcomposite row)

370+ composite fields = K $

371+ -- <number of fields: 4 bytes>

372+ -- [for each field]

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

374+ -- [if value is NULL]

375+ -- <-1: 4 bytes>

376+ -- [else]

377+ -- <length of value: 4 bytes>

378+ -- <value: <length> bytes>

379+ -- [end if]

380+ -- [end for]

381+ int32BE (fromIntegral (lengthSList (Proxy @xs))) <>

382+ let

383+ each

384+ :: OidOfField field

385+ => K (Maybe Encoding.Encoding) field

386+ -> Encoding.Encoding

387+ each (K field :: K (Maybe Encoding.Encoding) field) =

388+ word32BE (getOid (oidOfField @field))

389+ <> case field of

390+ Nothing -> int64BE (-1)

391+ Just value ->

392+ int32BE (fromIntegral (builderLength value))

393+ <> value

394+ in

395+ hcfoldMap (Proxy @OidOfField) each fields

396+

397+ in

398+ composite . encoders . toRecord . getComposite

399+

400+-- | The object identifier of a `PGType`.

401+--

402+-- >>> :set -XTypeApplications

403+-- >>> oidOf @'PGbool

404+-- Oid 16

405+class OidOf (ty :: PGType) where oidOf :: LibPQ.Oid

406+instance OidOf 'PGbool where oidOf = LibPQ.Oid 16

407+instance OidOf ('PGfixarray ns (null 'PGbool)) where oidOf = LibPQ.Oid 1000

408+instance OidOf ('PGvararray (null 'PGbool)) where oidOf = LibPQ.Oid 1000

409+instance OidOf 'PGint2 where oidOf = LibPQ.Oid 21

410+instance OidOf ('PGfixarray ns (null 'PGint2)) where oidOf = LibPQ.Oid 1005

411+instance OidOf ('PGvararray (null 'PGint2)) where oidOf = LibPQ.Oid 1005

412+instance OidOf 'PGint4 where oidOf = LibPQ.Oid 23

413+instance OidOf ('PGfixarray ns (null 'PGint4)) where oidOf = LibPQ.Oid 1007

414+instance OidOf ('PGvararray (null 'PGint4)) where oidOf = LibPQ.Oid 1007

415+instance OidOf 'PGint8 where oidOf = LibPQ.Oid 20

416+instance OidOf ('PGfixarray ns (null 'PGint8)) where oidOf = LibPQ.Oid 1016

417+instance OidOf ('PGvararray (null 'PGint8)) where oidOf = LibPQ.Oid 1016

418+instance OidOf 'PGnumeric where oidOf = LibPQ.Oid 1700

419+instance OidOf ('PGfixarray ns (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231

420+instance OidOf ('PGvararray (null 'PGnumeric)) where oidOf = LibPQ.Oid 1231

421+instance OidOf 'PGfloat4 where oidOf = LibPQ.Oid 700

422+instance OidOf ('PGfixarray ns (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021

423+instance OidOf ('PGvararray (null 'PGfloat4)) where oidOf = LibPQ.Oid 1021

424+instance OidOf 'PGfloat8 where oidOf = LibPQ.Oid 701

425+instance OidOf ('PGfixarray ns (null 'PGfloat8)) where oidOf = LibPQ.Oid 1022

426+instance OidOf ('PGvararray (null 'PGfloat8)) where oidOf = LibPQ.Oid 1022

427+instance OidOf 'PGmoney where oidOf = LibPQ.Oid 790

428+instance OidOf ('PGfixarray ns (null 'PGmoney)) where oidOf = LibPQ.Oid 791

429+instance OidOf ('PGvararray (null 'PGmoney)) where oidOf = LibPQ.Oid 791

430+instance OidOf ('PGchar n) where oidOf = LibPQ.Oid 18

431+instance OidOf ('PGfixarray ns (null ('PGchar n))) where oidOf = LibPQ.Oid 1002

432+instance OidOf ('PGvararray (null ('PGchar n))) where oidOf = LibPQ.Oid 1002

433+instance OidOf ('PGvarchar n) where oidOf = LibPQ.Oid 1043

434+instance OidOf ('PGfixarray ns (null ('PGvarchar n))) where oidOf = LibPQ.Oid 1015

435+instance OidOf ('PGvararray (null ('PGvarchar n))) where oidOf = LibPQ.Oid 1015

436+instance OidOf 'PGtext where oidOf = LibPQ.Oid 25

437+instance OidOf ('PGfixarray ns (null 'PGtext)) where oidOf = LibPQ.Oid 1009

438+instance OidOf ('PGvararray (null 'PGtext)) where oidOf = LibPQ.Oid 1009

439+instance OidOf 'PGbytea where oidOf = LibPQ.Oid 17

440+instance OidOf ('PGfixarray ns (null 'PGbytea)) where oidOf = LibPQ.Oid 1001

441+instance OidOf ('PGvararray (null 'PGbytea)) where oidOf = LibPQ.Oid 1001

442+instance OidOf 'PGtimestamp where oidOf = LibPQ.Oid 1114

443+instance OidOf ('PGfixarray ns (null 'PGtimestamp)) where oidOf = LibPQ.Oid 1115

444+instance OidOf ('PGvararray (null 'PGtimestamp)) where oidOf = LibPQ.Oid 1115

445+instance OidOf 'PGtimestamptz where oidOf = LibPQ.Oid 1184

446+instance OidOf ('PGfixarray ns (null 'PGtimestamptz)) where oidOf = LibPQ.Oid 1185

447+instance OidOf ('PGvararray (null 'PGtimestamptz)) where oidOf = LibPQ.Oid 1185

448+instance OidOf 'PGdate where oidOf = LibPQ.Oid 1082

449+instance OidOf ('PGfixarray ns (null 'PGdate)) where oidOf = LibPQ.Oid 1182

450+instance OidOf ('PGvararray (null 'PGdate)) where oidOf = LibPQ.Oid 1182

451+instance OidOf 'PGtime where oidOf = LibPQ.Oid 1083

452+instance OidOf ('PGfixarray ns (null 'PGtime)) where oidOf = LibPQ.Oid 1183

453+instance OidOf ('PGvararray (null 'PGtime)) where oidOf = LibPQ.Oid 1183

454+instance OidOf 'PGtimetz where oidOf = LibPQ.Oid 1266

455+instance OidOf ('PGfixarray ns (null 'PGtimetz)) where oidOf = LibPQ.Oid 1270

456+instance OidOf ('PGvararray (null 'PGtimetz)) where oidOf = LibPQ.Oid 1270

457+instance OidOf 'PGinterval where oidOf = LibPQ.Oid 1186

458+instance OidOf ('PGfixarray ns (null 'PGinterval)) where oidOf = LibPQ.Oid 1187

459+instance OidOf ('PGvararray (null 'PGinterval)) where oidOf = LibPQ.Oid 1187

460+instance OidOf 'PGuuid where oidOf = LibPQ.Oid 2950

461+instance OidOf ('PGfixarray ns (null 'PGuuid)) where oidOf = LibPQ.Oid 2951

462+instance OidOf ('PGvararray (null 'PGuuid)) where oidOf = LibPQ.Oid 2951

463+instance OidOf 'PGinet where oidOf = LibPQ.Oid 869

464+instance OidOf ('PGfixarray ns (null 'PGinet)) where oidOf = LibPQ.Oid 1041

465+instance OidOf ('PGvararray (null 'PGinet)) where oidOf = LibPQ.Oid 1041

466+instance OidOf 'PGjson where oidOf = LibPQ.Oid 114

467+instance OidOf ('PGfixarray ns (null 'PGjson)) where oidOf = LibPQ.Oid 199

468+instance OidOf ('PGvararray (null 'PGjson)) where oidOf = LibPQ.Oid 199

469+instance OidOf 'PGjsonb where oidOf = LibPQ.Oid 3802

470+instance OidOf ('PGfixarray ns (null 'PGjsonb)) where oidOf = LibPQ.Oid 3807

471+instance OidOf ('PGvararray (null 'PGjsonb)) where oidOf = LibPQ.Oid 3807

472+instance OidOf 'PGtsvector where oidOf = LibPQ.Oid 3614

473+instance OidOf ('PGfixarray ns (null 'PGtsvector)) where oidOf = LibPQ.Oid 3643

474+instance OidOf ('PGvararray (null 'PGtsvector)) where oidOf = LibPQ.Oid 3643

475+instance OidOf 'PGtsquery where oidOf = LibPQ.Oid 3615

476+instance OidOf ('PGfixarray ns (null 'PGtsquery)) where oidOf = LibPQ.Oid 3645

477+instance OidOf ('PGvararray (null 'PGtsquery)) where oidOf = LibPQ.Oid 3645

478+instance OidOf 'PGoid where oidOf = LibPQ.Oid 26

479+instance OidOf ('PGfixarray ns (null 'PGoid)) where oidOf = LibPQ.Oid 1028

480+instance OidOf ('PGvararray (null 'PGoid)) where oidOf = LibPQ.Oid 1028

481+instance OidOf ('PGrange 'PGint4) where oidOf = LibPQ.Oid 3904

482+instance OidOf ('PGfixarray ns (null ('PGrange 'PGint4))) where oidOf = LibPQ.Oid 3905

483+instance OidOf ('PGvararray (null ('PGrange 'PGint4))) where oidOf = LibPQ.Oid 3905

484+instance OidOf ('PGrange 'PGint8) where oidOf = LibPQ.Oid 3926

485+instance OidOf ('PGfixarray ns (null ('PGrange 'PGint8))) where oidOf = LibPQ.Oid 3927

486+instance OidOf ('PGvararray (null ('PGrange 'PGint8))) where oidOf = LibPQ.Oid 3927

487+instance OidOf ('PGrange 'PGnumeric) where oidOf = LibPQ.Oid 3906

488+instance OidOf ('PGfixarray ns (null ('PGrange 'PGnumeric))) where oidOf = LibPQ.Oid 3907

489+instance OidOf ('PGvararray (null ('PGrange 'PGnumeric))) where oidOf = LibPQ.Oid 3907

490+instance OidOf ('PGrange 'PGtimestamp) where oidOf = LibPQ.Oid 3908

491+instance OidOf ('PGfixarray ns (null ('PGrange 'PGtimestamp))) where oidOf = LibPQ.Oid 3909

492+instance OidOf ('PGvararray (null ('PGrange 'PGtimestamp))) where oidOf = LibPQ.Oid 3909

493+instance OidOf ('PGrange 'PGtimestamptz) where oidOf = LibPQ.Oid 3910

494+instance OidOf ('PGfixarray ns (null ('PGrange 'PGtimestamptz))) where oidOf = LibPQ.Oid 3911

495+instance OidOf ('PGvararray (null ('PGrange 'PGtimestamptz))) where oidOf = LibPQ.Oid 3911

496+instance OidOf ('PGrange 'PGdate) where oidOf = LibPQ.Oid 3912

497+instance OidOf ('PGfixarray ns (null ('PGrange 'PGdate))) where oidOf = LibPQ.Oid 3913

498+instance OidOf ('PGvararray (null ('PGrange 'PGdate))) where oidOf = LibPQ.Oid 3913

499+instance {-# OVERLAPPABLE #-} OidOf ('PGrange ty) where oidOf = LibPQ.invalidOid

500+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGrange ty))) where oidOf = LibPQ.invalidOid

501+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGrange ty))) where oidOf = LibPQ.invalidOid

502+instance {-# OVERLAPPABLE #-} OidOf ('PGcomposite row) where oidOf = LibPQ.invalidOid

503+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGcomposite row))) where oidOf = LibPQ.invalidOid

504+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGcomposite row))) where oidOf = LibPQ.invalidOid

505+instance {-# OVERLAPPABLE #-} OidOf ('PGenum labels) where oidOf = LibPQ.invalidOid

506+instance {-# OVERLAPPABLE #-} OidOf ('PGfixarray ns (null ('PGenum labels))) where oidOf = LibPQ.invalidOid

507+instance {-# OVERLAPPABLE #-} OidOf ('PGvararray (null ('PGenum labels))) where oidOf = LibPQ.invalidOid

508+

509+class OidOfParam (ty :: NullityType) where oidOfParam :: Oid

510+instance OidOf ty => OidOfParam (null ty) where oidOfParam = oidOf @ty

511+

512+-- | Lifts a `OidOf` constraint to a field.

513+class OidOfField (field :: (Symbol, NullityType)) where

514+ oidOfField :: Oid

515+instance OidOf ty => OidOfField (alias ::: nullity ty) where

516+ oidOfField = oidOf @ty

517+

518+-- | A `ToNullityParam` constraint gives an encoding of a Haskell `Type` into

519+-- into the binary format of a PostgreSQL `NullityType`.

520+class ToNullityParam (x :: Type) (ty :: NullityType) where

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

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

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

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

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

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

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

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

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

526+

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

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

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

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

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

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

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

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

535+

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

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

538+-- You should not define instances for

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

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

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

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

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

544+ . toNullityParam @x @ty

545+instance

546+ ( IsProductType product xs

547+ , Length xs ~ dim

548+ , All ((~) x) xs

549+ , ToFixArray x dims ty )

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

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

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

140

553

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

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

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

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

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

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

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

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

145class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

558class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

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

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

@@ -152,115 +565,257 @@ class SListI tys => ToParams (x :: Type) (tys :: [NullityType]) where

152 -- >>> instance Generic Tuple

565 -- >>> instance Generic Tuple

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

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

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

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

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

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

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

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

157 => ToParams x tys where

570 => ToParams x tys where

158 toParams

571 toParams

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

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

160 . unZ . unSOP . from

573 . unZ . unSOP . from

161

574

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

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

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

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

164class FromValue (pg :: PGType) (y :: Type) where

577class FromValue (pg :: PGType) (y :: Type) where

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

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

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

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

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

580+ fromValue :: Decoding.Value y

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

595+instance FromValue 'PGtext String where

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

180instance FromValue 'PGbytea Strict.ByteString where

597instance FromValue 'PGbytea Strict.ByteString where

181− fromValue _ = Decoding.bytea_strict

598+ fromValue = Decoding.bytea_strict

182instance FromValue 'PGbytea Lazy.ByteString where

599instance FromValue 'PGbytea Lazy.ByteString where

183− fromValue _ = Decoding.bytea_lazy

600+ fromValue = Decoding.bytea_lazy

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

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

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

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

186instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where

603instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where

187− fromValue _ = Decoding.timetz_int

604+ fromValue = Decoding.timetz_int

188instance FromValue 'PGtimestamp LocalTime where

605instance FromValue 'PGtimestamp LocalTime where

189− fromValue _ = Decoding.timestamp_int

606+ fromValue = Decoding.timestamp_int

190instance FromValue 'PGtimestamptz UTCTime where

607instance FromValue 'PGtimestamptz UTCTime where

191− fromValue _ = Decoding.timestamptz_int

608+ fromValue = Decoding.timestamptz_int

192instance FromValue 'PGinterval DiffTime where

609instance FromValue 'PGinterval DiffTime where

193− fromValue _ = Decoding.interval_int

610+ fromValue = Decoding.interval_int

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

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

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

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

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

614+ fromValue = Json <$>

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

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

617+ fromValue = Jsonb <$>

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

619+instance FromValue pg y

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

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

197− fromValue _ = Decoding.array

621+ fromValue =

622+ let

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

624+ in

198− (Decoding.dimensionArray Vector.replicateM

625+ Decoding.array $ Decoding.dimensionArray rep

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

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

627+instance FromValue pg y

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

629+ fromValue =

630+ let

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

632+ in

633+ Decoding.array $ Decoding.dimensionArray rep

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

635+instance FromValue pg y

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

637+ fromValue =

638+ let

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

640+ in

641+ Decoding.array $ Decoding.dimensionArray rep

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

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

643+instance FromValue pg y

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

645+ fromValue =

646+ let

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

648+ in

649+ Decoding.array $ Decoding.dimensionArray rep

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

651+instance FromFixArray dims ty y

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

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

654+instance

655+ ( IsEnumType y

656+ , HasDatatypeInfo y

657+ , LabelsPG y ~ labels

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

201− fromValue _ = Decoding.array

659+ fromValue =

202− (Decoding.dimensionArray Vector.replicateM

660+ let

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

661+ greadConstructor

204−

662+ :: All ((~) '[]) xss

663+ => NP ConstructorInfo xss

664+ -> String

665+ -> Maybe (SOP I xss)

666+ greadConstructor Nil _ = Nothing

667+ greadConstructor (constructor :* constructors) name =

668+ if name == constructorName constructor

669+ then Just (SOP (Z Nil))

670+ else SOP . S . unSOP <$> greadConstructor constructors name

671+ in

672+ fmap Enumerated

673+ . Decoding.enum

674+ $ fmap to

675+ . greadConstructor (constructorInfo (datatypeInfo (Proxy @y)))

676+ . Strict.Text.unpack

677+instance

678+ ( FromRow fields y

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

680+ fromValue =

681+ let

682+ -- <number of fields: 4 bytes>

683+ -- [for each field]

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

685+ -- [if value is NULL]

686+ -- <-1: 4 bytes>

687+ -- [else]

688+ -- <length of value: 4 bytes>

689+ -- <value: <length> bytes>

690+ -- [end if]

691+ -- [end for]

692+ composite = Decoding.valueParser $ do

693+ unitOfSize 4

694+ hsequence' $ hpure $ Comp $ do

695+ unitOfSize 4

696+ len <- sized 4 Decoding.int

697+ if len == -1

698+ then return (K Nothing)

699+ else K . Just <$> bytesOfSize len

700+ in

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

702+

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

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

206−-- to a decoding of a @(Symbol, ColumnType)@ to a `Type`,

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

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

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

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

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

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

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

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

708+ fromField

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

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

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

214− -- Id {getId = 1}

215− --

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

217− -- Just (Id {getId = 1})

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

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

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

219instance FromValue pg y

711instance FromValue pg y

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

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

221− fromColumnValue = \case

713+ fromField = Comp . \case

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

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

223− K (Just bytes) ->

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

224− let

225− errOrValue =

226− Decoding.valueParser (fromValue @pg @y Proxy) bytes

716+ Decoding.valueParser (fromValue @pg) bytestring

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

228− in

229− either err id errOrValue

230instance FromValue pg y

717instance FromValue pg y

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

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

232− fromColumnValue (K nullOrBytes)

719+ fromField = Comp . \case

233− = either err id

720+ K Nothing -> Right $ P Nothing

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

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

235− <$> nullOrBytes

722+ Decoding.valueParser (fromValue @pg) bytestring

236− where

723+

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

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

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

726+-- You should not define instances for

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

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

729+ fromFixArray :: Decoding.Array y

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

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

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

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

734+instance

735+ ( IsProductType product ys

736+ , Length ys ~ dim

737+ , All ((~) y) ys

738+ , FromFixArray dims ty y )

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

740+ fromFixArray =

741+ let

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

743+ in

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

238

745

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

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

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

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

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

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

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

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

243-- provide `FromRow` instances.

750-- provide `FromRow` instances.

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

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

245 -- | >>> :set -XOverloadedStrings

752 -- | >>> :set -XOverloadedStrings

246 -- >>> import Data.Text

753 -- >>> import Data.Text

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

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

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

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

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

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

250 -- >>> instance Generic UserRow

757 -- >>> instance Generic UserRow

251 -- >>> instance HasDatatypeInfo UserRow

758 -- >>> instance HasDatatypeInfo UserRow

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

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

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

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

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

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

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

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

256instance

763instance

257− ( SListI results

764+ ( SListI result

258− , IsProductType y ys

765+ , IsRecord y ys

259− , AllZip FromColumnValue results ys

766+ , AllZip FromField result ys

260− , SameFields (DatatypeInfoOf y) results

261− ) => FromRow results y where

767+ ) => FromRow result y where

262 fromRow

768 fromRow

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

769+ = fmap fromRecord

770+ . hsequence'

771+ . htrans (Proxy @FromField) fromField

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

773+-- P records

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

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

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

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

778+-- instance

779+-- ( row ~ Join row1 row2

780+-- , FromRow row1 hask1

781+-- , FromRow row2 hask2

782+-- , SListI row

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

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

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

786+-- instance

787+-- ( row ~ Join row1 row23

788+-- , FromRow row1 hask1

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

790+-- , SListI row

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

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

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

794+-- hask1 <- fromRow row1

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

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

797+-- instance

798+-- ( row ~ Join row1 row234

799+-- , FromRow row1 hask1

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

801+-- , SListI row

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

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

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

805+-- hask1 <- fromRow row1

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

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

808+-- instance

809+-- ( row ~ Join row1 row2345

810+-- , FromRow row1 hask1

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

812+-- , SListI row

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

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

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

816+-- hask1 <- fromRow row1

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

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

264

819

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

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

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

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

@@ -270,8 +825,24 @@ instance

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

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

271--

826--

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

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

273−-- Only {fromOnly = Just "bar"}

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

274newtype Only x = Only { fromOnly :: x }

829newtype Only x = Only { fromOnly :: x }

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

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

276instance Generic (Only x)

831instance Generic (Only x)

277instance HasDatatypeInfo (Only x)

832instance HasDatatypeInfo (Only x)

833+

834+foldlN

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

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

837+foldlN f z = \case

838+ Nil -> z

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

840+

841+replicateMN

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

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

844+replicateMN mx = hsequence' $

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

846+

847+getOid :: LibPQ.Oid -> Word32

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

squeal-postgresql/src/Squeal/PostgreSQL/Definition.hs+29−804

@@ -9,849 +9,74 @@ Squeal data definition language.

9-}

11{-# LANGUAGE

12+ AllowAmbiguousTypes

12− ConstraintKinds

13+ , ConstraintKinds

13− , DataKinds

14+ , DeriveAnyClass

14− , DeriveDataTypeable

15 , DeriveGeneric

16+ , DerivingStrategies

16 , FlexibleContexts

17 , FlexibleContexts

17 , FlexibleInstances

18 , FlexibleInstances

18 , GADTs

19 , GADTs

19− , GeneralizedNewtypeDeriving

20− , KindSignatures

21 , LambdaCase

20 , LambdaCase

22 , MultiParamTypeClasses

21 , MultiParamTypeClasses

22+ , OverloadedLabels

23 , OverloadedStrings

24 , RankNTypes

25 , ScopedTypeVariables

26− , StandaloneDeriving

27 , TypeApplications

26 , TypeApplications

28 , TypeInType

27 , TypeInType

29 , TypeOperators

28 , TypeOperators

29+ , UndecidableSuperClasses

30+ , UndecidableInstances

30#-}

31#-}

32module Squeal.PostgreSQL.Definition

33module Squeal.PostgreSQL.Definition

33− ( -- * Definition

34+ ( -- * Definition

34− Definition (UnsafeDefinition, renderDefinition)

35+ Definition (..)

35 , (>>>)

36 , (>>>)

36− -- * Create

37+ , manipDefinition

37− , createTable

38− , createTableIfNotExists

39− , TableConstraintExpression (..)

40− , check

41− , unique

42− , primaryKey

43− , foreignKey

44− , ForeignKeyed

45− , OnDeleteClause (OnDeleteNoAction, OnDeleteRestrict, OnDeleteCascade)

46− , renderOnDeleteClause

47− , OnUpdateClause (OnUpdateNoAction, OnUpdateRestrict, OnUpdateCascade)

48− , renderOnUpdateClause

49− -- * Drop

50− , dropTable

51− -- * Alter

52− , alterTable

53− , alterTableRename

54− , AlterTable (UnsafeAlterTable, renderAlterTable)

55− , addConstraint

56− , dropConstraint

57− , AddColumn (addColumn)

58− , dropColumn

59− , renameColumn

60− , alterColumn

61− , AlterColumn (UnsafeAlterColumn, renderAlterColumn)

62− , setDefault

63− , dropDefault

64− , setNotNull

65− , dropNotNull

66− , alterType

67− -- * Views

68− , createView

69− , dropView

70− -- * Types

71− , createType

72− , createTypeEnum

73− , dropType

74− , ColumnTypeExpression (..)

75− , notNull

76− , null'

77− , default_

78− , serial2

79− , smallserial

80− , serial4

81− , serial

82− , serial8

83− , bigserial

84 ) where

38 ) where

86import Control.Category

40import Control.Category

87import Control.DeepSeq

41import Control.DeepSeq

88import Data.ByteString

42import Data.ByteString

89import Data.Monoid

43import Data.Monoid

90−import GHC.TypeLits

91import Prelude hiding ((.), id)

44import Prelude hiding ((.), id)

93−import qualified Generics.SOP as SOP

94import qualified GHC.Generics as GHC

46import qualified GHC.Generics as GHC

96−import Squeal.PostgreSQL.Expression

48+import Squeal.PostgreSQL.Manipulation

97−import Squeal.PostgreSQL.Query

98import Squeal.PostgreSQL.Render

49import Squeal.PostgreSQL.Render

99import Squeal.PostgreSQL.Schema

50import Squeal.PostgreSQL.Schema

100

52+-- $setup

53+-- >>> import Squeal.PostgreSQL

54+

101{-----------------------------------------

55{-----------------------------------------

102statements

56statements

103-----------------------------------------}

57-----------------------------------------}

104

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

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

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

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

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

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

108newtype Definition

62newtype Definition

109− (schema0 :: SchemaType)

63+ (schemas0 :: SchemasType)

110− (schema1 :: SchemaType)

64+ (schemas1 :: SchemasType)

111 = UnsafeDefinition { renderDefinition :: ByteString }

65 = UnsafeDefinition { renderDefinition :: ByteString }

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

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

113

68+instance RenderSQL (Definition schemas0 schemas1) where

69+ renderSQL = renderDefinition

70+

114instance Category Definition where

71instance Category Definition where

115 id = UnsafeDefinition ";"

72 id = UnsafeDefinition ";"

116 ddl1 . ddl0 = UnsafeDefinition $

73 ddl1 . ddl0 = UnsafeDefinition $

117− renderDefinition ddl0 <+> renderDefinition ddl1

74+ renderSQL ddl0 <> "\n" <> renderSQL ddl1

118−

75+

119−{-----------------------------------------

76+-- | A `Manipulation` without input or output can be run as a statement

120−CREATE statements

77+-- along with other `Definition`s, by embedding it using `manipDefinition`.

121−-----------------------------------------}

78+manipDefinition

122−

79+ :: Manipulation '[] schemas '[] '[]

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

80+ -- ^ no input or output

124−--

81+ -> Definition schemas schemas

125−-- >>> :set -XOverloadedLabels

82+manipDefinition = UnsafeDefinition . (<> ";") . renderSQL

126−-- >>> :{

127−-- renderDefinition $

128−-- createTable #tab ((int & null') `As` #a :* (real & null') `As` #b :* Nil) Nil

129−-- :}

130−-- "CREATE TABLE \"tab\" (\"a\" int NULL, \"b\" real NULL);"

131−createTable

132− :: ( KnownSymbol table

133− , columns ~ (col ': cols)

134− , SOP.SListI columns

135− , SOP.SListI constraints

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

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

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

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

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

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

142− -> Definition schema0 schema1

143−createTable tab columns constraints = UnsafeDefinition $

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

145−

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

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

148−-- `createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in the `Category` `Definition`.

149−--

150−-- >>> :set -XOverloadedLabels -XTypeApplications

151−-- >>> type Table = '[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGfloat4]

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

153−-- >>> :{

154−-- renderDefinition

155−-- (createTableIfNotExists #tab ((int & null') `As` #a :* (real & null') `As` #b :* Nil) Nil :: Definition Schema Schema)

156−-- :}

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

158−createTableIfNotExists

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

160− , SOP.SListI columns

161− , SOP.SListI constraints )

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

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

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

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

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

167− -> Definition schema schema

168−createTableIfNotExists tab columns constraints = UnsafeDefinition $

169− "CREATE TABLE IF NOT EXISTS"

170− <+> renderCreation tab columns constraints

171−

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

173−renderCreation

174− :: ( KnownSymbol table

175− , SOP.SListI columns

176− , SOP.SListI constraints )

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

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

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

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

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

182− -> ByteString

183−renderCreation tab columns constraints = renderAlias tab

184− <+> parenthesized

185− ( renderCommaSeparated renderColumnDef columns

186− <> ( case constraints of

187− Nil -> ""

188− _ -> ", " <>

189− renderCommaSeparated renderConstraint constraints ) )

190− <> ";"

191− where

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

193− renderColumnDef (ty `As` column) =

194− renderAlias column <+> renderColumnTypeExpression ty

195− renderConstraint

196− :: Aliased (TableConstraintExpression schema columns) constraint

197− -> ByteString

198− renderConstraint (constraint `As` alias) =

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

200−

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

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

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

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

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

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

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

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

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

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

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

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

213−newtype TableConstraintExpression

214− (schema :: SchemaType)

215− (table :: Symbol)

216− (tableConstraint :: TableConstraint)

217− = UnsafeTableConstraintExpression

218− { renderTableConstraintExpression :: ByteString }

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

220−

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

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

223−-- a Boolean (truth-value) expression.

224−--

225−-- >>> :{

226−-- type Schema = '[

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

228−-- "a" ::: 'NoDef :=> 'NotNull 'PGint4,

229−-- "b" ::: 'NoDef :=> 'NotNull 'PGint4

230−-- ])]

231−-- :}

232−--

233−-- >>> :{

234−-- let

235−-- definition :: Definition '[] Schema

236−-- definition = createTable #tab

237−-- ( (int & notNull) `As` #a :*

238−-- (int & notNull) `As` #b :* Nil )

239−-- ( check (#a :* #b :* Nil) (#a .> #b) `As` #inequality :* Nil )

240−-- :}

241−--

242−-- >>> renderDefinition definition

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

244−check

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

246− , HasAll aliases (TableToColumns table) subcolumns )

247− => NP Alias aliases

248− -> (forall tab. Condition '[tab ::: ColumnsToRelation subcolumns] 'Ungrouped '[])

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

250−check _cols condition = UnsafeTableConstraintExpression $

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

252−

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

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

255−--

256−-- >>> :{

257−-- type Schema = '[

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

259−-- "a" ::: 'NoDef :=> 'Null 'PGint4,

260−-- "b" ::: 'NoDef :=> 'Null 'PGint4

261−-- ])]

262−-- :}

263−--

264−-- >>> :{

265−-- let

266−-- definition :: Definition '[] Schema

267−-- definition = createTable #tab

268−-- ( (int & null') `As` #a :*

269−-- (int & null') `As` #b :* Nil )

270−-- ( unique (#a :* #b :* Nil) `As` #uq_a_b :* Nil )

271−-- :}

272−--

273−-- >>> renderDefinition definition

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

275−unique

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

277− , HasAll aliases (TableToColumns table) subcolumns )

278− => NP Alias aliases

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

280−unique columns = UnsafeTableConstraintExpression $

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

282−

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

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

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

286−--

287−-- >>> :{

288−-- type Schema = '[

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

290−-- "id" ::: 'Def :=> 'NotNull 'PGint4,

291−-- "name" ::: 'NoDef :=> 'NotNull 'PGtext

292−-- ])]

293−-- :}

294−--

295−-- >>> :{

296−-- let

297−-- definition :: Definition '[] Schema

298−-- definition = createTable #tab

299−-- ( serial `As` #id :*

300−-- (text & notNull) `As` #name :* Nil )

301−-- ( primaryKey #id `As` #pk_id :* Nil )

302−-- :}

303−--

304−-- >>> renderDefinition definition

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

306−primaryKey

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

308− , HasAll aliases (TableToColumns table) subcolumns

309− , AllNotNull subcolumns )

310− => NP Alias aliases

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

312−primaryKey columns = UnsafeTableConstraintExpression $

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

314−

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

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

317−-- another table. We say this maintains the referential integrity

318−-- between two related tables.

319−--

320−-- >>> :{

321−-- type Schema =

322−-- '[ "users" ::: 'Table (

323−-- '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

324−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

325−-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext

326−-- ])

327−-- , "emails" ::: 'Table (

328−-- '[ "pk_emails" ::: 'PrimaryKey '["id"]

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

330−-- ] :=>

331−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

332−-- , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

333−-- , "email" ::: 'NoDef :=> 'Null 'PGtext

334−-- ])

335−-- ]

336−-- :}

337−--

338−-- >>> :{

339−-- let

340−-- setup :: Definition '[] Schema

341−-- setup =

342−-- createTable #users

343−-- ( serial `As` #id :*

344−-- (text & notNull) `As` #name :* Nil )

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

346−-- createTable #emails

347−-- ( serial `As` #id :*

348−-- (int & notNull) `As` #user_id :*

349−-- (text & null') `As` #email :* Nil )

350−-- ( primaryKey #id `As` #pk_emails :*

351−-- foreignKey #user_id #users #id

352−-- OnDeleteCascade OnUpdateCascade `As` #fk_user_id :* Nil )

353−-- in renderDefinition setup

354−-- :}

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

356−--

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

358−--

359−-- >>> :{

360−-- type Schema =

361−-- '[ "employees" ::: 'Table (

362−-- '[ "employees_pk" ::: 'PrimaryKey '["id"]

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

364−-- ] :=>

365−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

366−-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext

367−-- , "employer_id" ::: 'NoDef :=> 'Null 'PGint4

368−-- ])

369−-- ]

370−-- :}

371−--

372−-- >>> :{

373−-- let

374−-- setup :: Definition '[] Schema

375−-- setup =

376−-- createTable #employees

377−-- ( serial `As` #id :*

378−-- (text & notNull) `As` #name :*

379−-- (integer & null') `As` #employer_id :* Nil )

380−-- ( primaryKey #id `As` #employees_pk :*

381−-- foreignKey #employer_id #employees #id

382−-- OnDeleteCascade OnUpdateCascade `As` #employees_employer_fk :* Nil )

383−-- in renderDefinition setup

384−-- :}

385−-- "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);"

386−--

387−foreignKey

388− :: (ForeignKeyed schema child parent

389− table reftable

390− columns refcolumns

391− constraints cols

392− reftys tys )

393− => NP Alias columns

394− -- ^ column or columns in the table

395− -> Alias parent

396− -- ^ reference table

397− -> NP Alias refcolumns

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

399− -> OnDeleteClause

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

401− -> OnUpdateClause

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

403− -> TableConstraintExpression schema child

404− ('ForeignKey columns parent refcolumns)

405−foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $

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

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

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

409− <+> renderOnDeleteClause ondel

410− <+> renderOnUpdateClause onupd

411−

412−type ForeignKeyed schema

413− child parent

414− table reftable

415− columns refcolumns

416− constraints cols

417− reftys tys =

418− ( Has child schema ('Table table)

419− , Has parent schema ('Table reftable)

420− , HasAll columns (TableToColumns table) tys

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

422− , HasAll refcolumns cols reftys

423− , SOP.AllZip SamePGType tys reftys

424− , Uniquely refcolumns constraints )

425−

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

427−data OnDeleteClause

428− = OnDeleteNoAction

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

430− -- an error is raised

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

432− | OnDeleteCascade

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

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

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

436−instance NFData OnDeleteClause

437−

438−-- | Render `OnDeleteClause`.

439−renderOnDeleteClause :: OnDeleteClause -> ByteString

440−renderOnDeleteClause = \case

441− OnDeleteNoAction -> "ON DELETE NO ACTION"

442− OnDeleteRestrict -> "ON DELETE RESTRICT"

443− OnDeleteCascade -> "ON DELETE CASCADE"

444−

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

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

447−data OnUpdateClause

448− = OnUpdateNoAction

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

450− -- an error is raised

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

452− | OnUpdateCascade

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

454− -- into the referencing row(s)

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

456−instance NFData OnUpdateClause

457−

458−-- | Render `OnUpdateClause`.

459−renderOnUpdateClause :: OnUpdateClause -> ByteString

460−renderOnUpdateClause = \case

461− OnUpdateNoAction -> "ON UPDATE NO ACTION"

462− OnUpdateRestrict -> "ON UPDATE RESTRICT"

463− OnUpdateCascade -> "ON UPDATE CASCADE"

464−

465−{-----------------------------------------

466−DROP statements

467−-----------------------------------------}

468−

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

470−--

471−-- >>> :{

472−-- let

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

474−-- definition = dropTable #muh_table

475−-- :}

476−--

477−-- >>> renderDefinition definition

478−-- "DROP TABLE \"muh_table\";"

479−dropTable

480− :: Has table schema ('Table t)

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

482− -> Definition schema (Drop table schema)

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

484−

485−{-----------------------------------------

486−ALTER statements

487−-----------------------------------------}

488−

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

490−alterTable

491− :: KnownSymbol alias

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

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

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

495−alterTable tab alteration = UnsafeDefinition $

496− "ALTER TABLE"

497− <+> renderAlias tab

498− <+> renderAlterTable alteration

499− <> ";"

500−

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

502−--

503−-- >>> renderDefinition $ alterTableRename #foo #bar

504−-- "ALTER TABLE \"foo\" RENAME TO \"bar\";"

505−alterTableRename

506− :: (KnownSymbol table0, KnownSymbol table1)

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

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

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

510−alterTableRename table0 table1 = UnsafeDefinition $

511− "ALTER TABLE" <+> renderAlias table0

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

513−

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

515−-- of a table.

516−newtype AlterTable

517− (alias :: Symbol)

518− (table :: TableType)

519− (schema :: SchemaType) =

520− UnsafeAlterTable {renderAlterTable :: ByteString}

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

522−

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

524−--

525−-- >>> :{

526−-- let

527−-- definition :: Definition

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

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

530−-- definition = alterTable #tab (addConstraint #positive (check (#col :* Nil) (#col .> 0)))

531−-- in renderDefinition definition

532−-- :}

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

534−addConstraint

535− :: ( KnownSymbol alias

536− , Has tab schema ('Table table0)

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

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

539− => Alias alias

540− -> TableConstraintExpression schema tab constraint

541− -- ^ constraint to add

542− -> AlterTable tab table1 schema

543−addConstraint alias constraint = UnsafeAlterTable $

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

545− <+> renderTableConstraintExpression constraint

546−

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

548−--

549−-- >>> :{

550−-- let

551−-- definition :: Definition

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

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

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

555−-- in renderDefinition definition

556−-- :}

557−-- "ALTER TABLE \"tab\" DROP CONSTRAINT \"positive\";"

558−dropConstraint

559− :: ( KnownSymbol constraint

560− , Has tab schema ('Table table0)

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

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

563− => Alias constraint

564− -- ^ constraint to drop

565− -> AlterTable tab table1 schema

566−dropConstraint constraint = UnsafeAlterTable $

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

568−

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

570−class AddColumn ty where

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

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

573− --

574− -- >>> :{

575− -- let

576− -- definition :: Definition

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

578− -- '["tab" ::: 'Table ('[] :=>

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

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

581− -- definition = alterTable #tab (addColumn #col2 (text & null' & default_ "foo"))

582− -- in renderDefinition definition

583− -- :}

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

585− --

586− -- >>> :{

587− -- let

588− -- definition :: Definition

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

590− -- '["tab" ::: 'Table ('[] :=>

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

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

593− -- definition = alterTable #tab (addColumn #col2 (text & null'))

594− -- in renderDefinition definition

595− -- :}

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

597− addColumn

598− :: ( KnownSymbol column

599− , Has tab schema ('Table table0)

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

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

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

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

604− -> AlterTable tab table1 schema

605− addColumn column ty = UnsafeAlterTable $

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

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

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

609−

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

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

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

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

614−--

615−-- >>> :{

616−-- let

617−-- definition :: Definition

618−-- '["tab" ::: 'Table ('[] :=>

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

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

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

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

623−-- in renderDefinition definition

624−-- :}

625−-- "ALTER TABLE \"tab\" DROP COLUMN \"col2\";"

626−dropColumn

627− :: ( KnownSymbol column

628− , Has tab schema ('Table table0)

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

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

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

632− -> AlterTable tab table1 schema

633−dropColumn column = UnsafeAlterTable $

634− "DROP COLUMN" <+> renderAlias column

635−

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

637−--

638−-- >>> :{

639−-- let

640−-- definition :: Definition

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

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

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

644−-- in renderDefinition definition

645−-- :}

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

647−renameColumn

648− :: ( KnownSymbol column0

649− , KnownSymbol column1

650− , Has tab schema ('Table table0)

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

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

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

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

655− -> AlterTable tab table1 schema

656−renameColumn column0 column1 = UnsafeAlterTable $

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

658−

659−-- | An `alterColumn` alters a single column.

660−alterColumn

661− :: ( KnownSymbol column

662− , Has tab schema ('Table table0)

663− , table0 ~ (constraints :=> columns)

664− , Has column columns ty0

665− , tables1 ~ (constraints :=> Alter column ty1 columns))

666− => Alias column -- ^ column to alter

667− -> AlterColumn schema ty0 ty1 -- ^ alteration to perform

668− -> AlterTable tab table1 schema

669−alterColumn column alteration = UnsafeAlterTable $

670− "ALTER COLUMN" <+> renderAlias column <+> renderAlterColumn alteration

671−

672−-- | An `AlterColumn` describes the alteration to perform on a single column.

673−newtype AlterColumn (schema :: SchemaType) (ty0 :: ColumnType) (ty1 :: ColumnType) =

674− UnsafeAlterColumn {renderAlterColumn :: ByteString}

675− deriving (GHC.Generic,Show,Eq,Ord,NFData)

676−

677−-- | A `setDefault` sets a new default for a column. Note that this doesn't

678−-- affect any existing rows in the table, it just changes the default for

679−-- future insert and update commands.

680−--

681−-- >>> :{

682−-- let

683−-- definition :: Definition

684−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

685−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

686−-- definition = alterTable #tab (alterColumn #col (setDefault 5))

687−-- in renderDefinition definition

688−-- :}

689−-- "ALTER TABLE \"tab\" ALTER COLUMN \"col\" SET DEFAULT 5;"

690−setDefault

691− :: Expression '[] 'Ungrouped '[] ty -- ^ default value to set

692− -> AlterColumn schema (constraint :=> ty) ('Def :=> ty)

693−setDefault expression = UnsafeAlterColumn $

694− "SET DEFAULT" <+> renderExpression expression

695−

696−-- | A `dropDefault` removes any default value for a column.

697−--

698−-- >>> :{

699−-- let

700−-- definition :: Definition

701−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]

702−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

703−-- definition = alterTable #tab (alterColumn #col dropDefault)

704−-- in renderDefinition definition

705−-- :}

706−-- "ALTER TABLE \"tab\" ALTER COLUMN \"col\" DROP DEFAULT;"

707−dropDefault :: AlterColumn schema ('Def :=> ty) ('NoDef :=> ty)

708−dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"

709−

710−-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.

711−-- The constraint will be checked immediately, so the table data must satisfy

712−-- the constraint before it can be added.

713−--

714−-- >>> :{

715−-- let

716−-- definition :: Definition

717−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

718−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

719−-- definition = alterTable #tab (alterColumn #col setNotNull)

720−-- in renderDefinition definition

721−-- :}

722−-- "ALTER TABLE \"tab\" ALTER COLUMN \"col\" SET NOT NULL;"

723−setNotNull

724− :: AlterColumn schema (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)

725−setNotNull = UnsafeAlterColumn $ "SET NOT NULL"

726−

727−-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.

728−--

729−-- >>> :{

730−-- let

731−-- definition :: Definition

732−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

733−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

734−-- definition = alterTable #tab (alterColumn #col dropNotNull)

735−-- in renderDefinition definition

736−-- :}

737−-- "ALTER TABLE \"tab\" ALTER COLUMN \"col\" DROP NOT NULL;"

738−dropNotNull

739− :: AlterColumn schema (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)

740−dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"

741−

742−-- | An `alterType` converts a column to a different data type.

743−-- This will succeed only if each existing entry in the column can be

744−-- converted to the new type by an implicit cast.

745−--

746−-- >>> :{

747−-- let

748−-- definition :: Definition

749−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]

750−-- '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]

751−-- definition =

752−-- alterTable #tab (alterColumn #col (alterType (numeric & notNull)))

753−-- in renderDefinition definition

754−-- :}

755−-- "ALTER TABLE \"tab\" ALTER COLUMN \"col\" TYPE numeric NOT NULL;"

756−alterType :: ColumnTypeExpression schema ty -> AlterColumn schema ty0 ty

757−alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty

758−

759−-- | create a view...

760−-- >>> :{

761−-- let

762−-- definition :: Definition

763−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]

764−-- '[ "abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

765−-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]

766−-- definition =

767−-- createView #bc (select (#b `As` #b :* #c `As` #c :* Nil) (from (table (#abc `As` #abc))))

768−-- in renderDefinition definition

769−-- :}

770−-- "CREATE VIEW \"bc\" AS SELECT \"b\" AS \"b\", \"c\" AS \"c\" FROM \"abc\" AS \"abc\";"

771−createView

772− :: KnownSymbol view

773− => Alias view -- ^ the name of the table to add

774− -> Query schema '[] relation

775− -- ^ query

776− -> Definition schema (Create view ('View relation) schema)

777−createView alias query = UnsafeDefinition $

778− "CREATE" <+> "VIEW" <+> renderAlias alias <+> "AS"

779− <+> renderQuery query <> ";"

780−

781−dropView

782− :: Has view schema ('View v)

783− => Alias view -- ^ view to remove

784− -> Definition schema (Drop view schema)

785−dropView v = UnsafeDefinition $ "DROP VIEW" <+> renderAlias v <> ";"

786−

787−createTypeEnum

788− :: (KnownSymbol enum, SOP.All KnownSymbol labels)

789− => Alias enum

790− -> NP Alias labels

791− -> Definition schema (Create enum ('Typedef ('PGenum labels)) schema)

792−createTypeEnum enum labels = UnsafeDefinition $

793− "CREATE" <+> "TYPE" <+> renderAlias enum <+> "AS" <+>

794− parenthesized (commaSeparated (renderAliases labels)) <> ";"

795−

796−createType

797− :: (KnownSymbol comp, SOP.SListI fields)

798− => Alias comp

799− -> NP (Aliased TypeExpression) fields

800− -> Definition schema (Create comp ('Typedef ('PGcomposite fields)) schema)

801−createType comp fields = UnsafeDefinition $

802− "CREATE" <+> "TYPE" <+> renderAlias comp <+> "AS" <+> parenthesized

803− (renderCommaSeparated (renderAliasedAs renderTypeExpression) fields) <> ";"

804−

805−dropType

806− :: Has tydef schema ('Typedef ty)

807− => Alias tydef

808− -> Definition schema (Drop tydef schema)

809−dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderAlias tydef <> ";"

810−

811−-- | `ColumnTypeExpression`s are used in `createTable` commands.

812−newtype ColumnTypeExpression (schema :: SchemaType) (ty :: ColumnType)

813− = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }

814− deriving (GHC.Generic,Show,Eq,Ord,NFData)

815−

816−instance (Has alias schema ('Typedef ty))

817− => IsLabel alias (ColumnTypeExpression schema ('NoDef :=> 'NotNull ty)) where

818− fromLabel = UnsafeColumnTypeExpression (renderAlias (fromLabel @alias))

819−

820−null'

821− :: TypeExpression ty

822− -> ColumnTypeExpression schema ('NoDef :=> 'Null ty)

823−null' ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NULL"

824−

825−-- | used in `createTable` commands as a column constraint to ensure

826−-- @NULL@ is not present

827−notNull

828− :: TypeExpression ty

829− -> ColumnTypeExpression schema (def :=> 'NotNull ty)

830−notNull ty = UnsafeColumnTypeExpression $ renderTypeExpression ty <+> "NOT NULL"

831−

832−-- | used in `createTable` commands as a column constraint to give a default

833−default_

834− :: Expression '[] 'Ungrouped '[] ty

835− -> ColumnTypeExpression schema ('NoDef :=> ty)

836− -> ColumnTypeExpression schema ('Def :=> ty)

837−default_ x ty = UnsafeColumnTypeExpression $

838− renderColumnTypeExpression ty <+> "DEFAULT" <+> renderExpression x

839−

840−-- | not a true type, but merely a notational convenience for creating

841−-- unique identifier columns with type `'PGint2`

842−serial2, smallserial

843− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint2)

844−serial2 = UnsafeColumnTypeExpression "serial2"

845−smallserial = UnsafeColumnTypeExpression "smallserial"

846−-- | not a true type, but merely a notational convenience for creating

847−-- unique identifier columns with type `'PGint4`

848−serial4, serial

849− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint4)

850−serial4 = UnsafeColumnTypeExpression "serial4"

851−serial = UnsafeColumnTypeExpression "serial"

852−-- | not a true type, but merely a notational convenience for creating

853−-- unique identifier columns with type `'PGint8`

854−serial8, bigserial

855− :: ColumnTypeExpression schema ('Def :=> 'NotNull 'PGint8)

856−serial8 = UnsafeColumnTypeExpression "serial8"

857−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+362−1065

@@ -1,19 +1,17 @@

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

14− , DataKinds

13+ , ConstraintKinds

15 , DeriveGeneric

14 , DeriveGeneric

16− , DeriveDataTypeable

17 , FlexibleContexts

15 , FlexibleContexts

18 , FlexibleInstances

16 , FlexibleInstances

19 , FunctionalDependencies

17 , FunctionalDependencies

@@ -22,8 +20,6 @@ Squeal expressions are the atoms used to build statements.

22 , LambdaCase

20 , LambdaCase

23 , MagicHash

21 , MagicHash

24 , OverloadedStrings

22 , OverloadedStrings

25− , PolyKinds

26− , RankNTypes

27 , ScopedTypeVariables

23 , ScopedTypeVariables

28 , StandaloneDeriving

24 , StandaloneDeriving

29 , TypeApplications

25 , TypeApplications

@@ -31,358 +27,356 @@ Squeal expressions are the atoms used to build statements.

31 , TypeInType

27 , TypeInType

32 , TypeOperators

28 , TypeOperators

33 , UndecidableInstances

29 , UndecidableInstances

30+ , RankNTypes

34#-}

31#-}

36−module Squeal.PostgreSQL.Expression

33+module Squeal.PostgreSQL.Expression

37 ( -- * Expression

34 ( -- * Expression

38− Expression (UnsafeExpression, renderExpression)

35+ Expression (..)

39− , HasParameter (param)

36+ , Expr

40− -- ** Null

37+ , type (-->)

41− , null_

38+ , FunctionDB

42− , unNull

43− , coalesce

44− , fromNull

45− , isNull

46− , isn'tNull

47− , matchNull

48− , nullIf

49− -- ** Arrays

50− , array

51− -- ** Functions

52− , unsafeBinaryOp

53− , unsafeUnaryOp

54 , unsafeFunction

39 , unsafeFunction

55− , atan2_

40+ , function

56− , cast

41+ , unsafeLeftOp

57− , quot_

42+ , leftOp

58− , rem_

43+ , unsafeRightOp

59− , trunc

44+ , rightOp

60− , round_

45+ , Operator

61− , ceiling_

46+ , OperatorDB

62− , greatest

47+ , unsafeBinaryOp

63− , least

48+ , binaryOp

64− -- ** Conditions

49+ , FunctionVar

65− , Condition

50+ , unsafeFunctionVar

66− , true

51+ , type (--->)

67− , false

52+ , FunctionNDB

68− , not_

53+ , unsafeFunctionN

69− , (.&&)

54+ , functionN

70− , (.||)

55+ , PGSubset (..)

71− , caseWhenThenElse

56+ , PGIntersect (..)

72− , ifThenElse

73− , (.==)

74− , (./=)

75− , (.>=)

76− , (.<)

77− , (.<=)

78− , (.>)

79− -- ** Time

80− , currentDate

81− , currentTime

82− , currentTimestamp

83− , localTime

84− , localTimestamp

85− -- ** Text

86− , lower

87− , upper

88− , charLength

89− , like

90− -- ** Aggregation

91− , unsafeAggregate, unsafeAggregateDistinct

92− , sum_, sumDistinct

93− , PGAvg (avg, avgDistinct)

94− , bitAnd, bitOr, boolAnd, boolOr

95− , bitAndDistinct, bitOrDistinct, boolAndDistinct, boolOrDistinct

96− , countStar

97− , count, countDistinct

98− , every, everyDistinct

99− , max_, maxDistinct, min_, minDistinct

100− -- * Tables

101− , Table (UnsafeTable, renderTable)

102− , View (UnsafeView, renderView)

103− -- * Types

104− , TypeExpression (UnsafeTypeExpression, renderTypeExpression)

105− , PGTyped (pgtype)

106− , bool

107− , int2

108− , smallint

109− , int4

110− , int

111− , integer

112− , int8

113− , bigint

114− , numeric

115− , float4

116− , real

117− , float8

118− , doublePrecision

119− , text

120− , char

121− , character

122− , varchar

123− , characterVarying

124− , bytea

125− , timestamp

126− , timestampWithTimeZone

127− , date

128− , time

129− , timeWithTimeZone

130− , interval

131− , uuid

132− , inet

133− , json

134− , jsonb

135− , vararray

136− , fixarray

137 -- * Re-export

57 -- * Re-export

138 , (&)

58 , (&)

139− , NP ((:*), Nil)

59+ , K (..)

60+ , unK

140 ) where

61 ) where

141

142import Control.Category

63import Control.Category

143import Control.DeepSeq

64import Control.DeepSeq

144import Data.ByteString (ByteString)

65import Data.ByteString (ByteString)

145import Data.Function ((&))

66import Data.Function ((&))

146−import Data.Monoid hiding (All)

67+import Data.Semigroup hiding (All)

147−import Data.Ratio

148import Data.String

68import Data.String

149−import Generics.SOP hiding (from)

69+import Generics.SOP hiding (All, from)

150import GHC.OverloadedLabels

70import GHC.OverloadedLabels

151import GHC.TypeLits

71import GHC.TypeLits

72+import Numeric

152import Prelude hiding (id, (.))

73import Prelude hiding (id, (.))

153

154import qualified GHC.Generics as GHC

75import qualified GHC.Generics as GHC

155

77+import Squeal.PostgreSQL.Alias

78+import Squeal.PostgreSQL.List

156import Squeal.PostgreSQL.Render

79import Squeal.PostgreSQL.Render

157import Squeal.PostgreSQL.Schema

80import Squeal.PostgreSQL.Schema

158

82+-- $setup

83+-- >>> import Squeal.PostgreSQL

84+

159{-----------------------------------------

85{-----------------------------------------

160column expressions

86column expressions

161-----------------------------------------}

87-----------------------------------------}

162

163{- | `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

164−such as in the target list of the `Squeal.PostgreSQL.Query.select` command,

91+`Squeal.PostgreSQL.Query.select` command,

165as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or

92as new column values in `Squeal.PostgreSQL.Manipulation.insertRow` or

166`Squeal.PostgreSQL.Manipulation.update`,

93`Squeal.PostgreSQL.Manipulation.update`,

167−or in search `Condition`s in a number of commands.

94+or in search `Squeal.PostgreSQL.Logic.Condition`s in a number of commands.

168

169The expression syntax allows the calculation of

96The expression syntax allows the calculation of

170values from primitive expression using arithmetic, logical,

97values from primitive expression using arithmetic, logical,

171and 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`.

172-}

113-}

173newtype Expression

114newtype Expression

174− (relations :: RelationsType)

115+ (outer :: FromType)

116+ (commons :: FromType)

175− (grouping :: Grouping)

117+ (grp :: Grouping)

118+ (schemas :: SchemasType)

176 (params :: [NullityType])

119 (params :: [NullityType])

120+ (from :: FromType)

177 (ty :: NullityType)

121 (ty :: NullityType)

178 = UnsafeExpression { renderExpression :: ByteString }

122 = UnsafeExpression { renderExpression :: ByteString }

179 deriving (GHC.Generic,Show,Eq,Ord,NFData)

123 deriving (GHC.Generic,Show,Eq,Ord,NFData)

180−

124+instance RenderSQL (Expression outer commons grp schemas params from ty) where

181−{- | A `HasParameter` constraint is used to indicate a value that is

125+ renderSQL = renderExpression

182−supplied externally to a SQL statement.

126+

183−`Squeal.PostgreSQL.PQ.manipulateParams`,

127+-- | An `Expr` is a closed `Expression`.

184−`Squeal.PostgreSQL.PQ.queryParams` and

128+-- It is a F@RankNType@ but don't be scared.

185−`Squeal.PostgreSQL.PQ.traversePrepared` support specifying data values

129+-- Think of it as an expression which sees no

186−separately from the SQL command string, in which case `param`s are used to

130+-- namespaces, so you can't use parameters

187−refer to the out-of-line data values.

131+-- or alias references. It can be used as

132+-- a simple piece of more complex `Expression`s.

133+type Expr x

134+ = forall outer commons grp schemas params from

135+ . Expression outer commons grp schemas params from x

136+ -- ^ cannot reference aliases

137+

138+-- | A @RankNType@ for binary operators.

139+type Operator x1 x2 y

140+ = forall outer commons grp schemas params from

141+ . Expression outer commons grp schemas params from x1

142+ -- ^ left input

143+ -> Expression outer commons grp schemas params from x2

144+ -- ^ right input

145+ -> Expression outer commons grp schemas params from y

146+ -- ^ output

147+

148+type OperatorDB schemas x1 x2 y

149+ = forall outer commons grp params from

150+ . Expression outer commons grp schemas params from x1

151+ -- ^ left input

152+ -> Expression outer commons grp schemas params from x2

153+ -- ^ right input

154+ -> Expression outer commons grp schemas params from y

155+ -- ^ output

156+

157+-- | A @RankNType@ for functions with a single argument.

158+-- These could be either function calls or unary operators.

159+-- This is a subtype of the usual Haskell function type `Prelude.->`,

160+-- indeed a subcategory as it is closed under the usual

161+-- `Prelude..` and `Prelude.id`.

162+type (-->) x y

163+ = forall outer commons grp schemas params from

164+ . Expression outer commons grp schemas params from x

165+ -- ^ input

166+ -> Expression outer commons grp schemas params from y

167+ -- ^ output

168+

169+type FunctionDB schemas x y

170+ = forall outer commons grp params from

171+ . Expression outer commons grp schemas params from x

172+ -- ^ input

173+ -> Expression outer commons grp schemas params from y

174+ -- ^ output

175+

176+{- | A @RankNType@ for functions with a fixed-length list of heterogeneous arguments.

177+Use the `*:` operator to end your argument lists, like so.

178+

179+>>> printSQL (unsafeFunctionN "fun" (true :* false :* localTime *: true))

180+fun(TRUE, FALSE, LOCALTIME, TRUE)

188-}

181-}

189−class (PGTyped (PGTypeOf ty), KnownNat n) => HasParameter

182+type (--->) xs y

190− (n :: Nat)

183+ = forall outer commons grp schemas params from

191− (params :: [NullityType])

184+ . NP (Expression outer commons grp schemas params from) xs

192− (ty :: NullityType)

185+ -- ^ inputs

193− | n params -> ty where

186+ -> Expression outer commons grp schemas params from y

194− param :: Expression relations grouping params ty

187+ -- ^ output

188+

189+type FunctionNDB schemas xs y

190+ = forall outer commons grp params from

191+ . NP (Expression outer commons grp schemas params from) xs

192+ -- ^ inputs

193+ -> Expression outer commons grp schemas params from y

194+ -- ^ output

195+

196+{- | A @RankNType@ for functions with a variable-length list of

197+homogeneous arguments and at least 1 more argument.

198+-}

199+type FunctionVar x0 x1 y

200+ = forall outer commons grp schemas params from

201+ . [Expression outer commons grp schemas params from x0]

202+ -- ^ inputs

203+ -> Expression outer commons grp schemas params from x1

204+ -- ^ must have at least 1 input

205+ -> Expression outer commons grp schemas params from y

206+ -- ^ output

207+

208+{- | >>> printSQL (unsafeFunctionVar "greatest" [true, null_] false)

209+greatest(TRUE, NULL, FALSE)

210+-}

211+unsafeFunctionVar :: ByteString -> FunctionVar x0 x1 y

195− param = UnsafeExpression $ parenthesized $

212+unsafeFunctionVar fun xs x = UnsafeExpression $ fun <> parenthesized

196− "$" <> renderNat (Proxy @n) <+> "::"

213+ (commaSeparated (renderSQL <$> xs) <> ", " <> renderSQL x)

197− <+> renderTypeExpression (pgtype @(PGTypeOf ty))

214+

198−instance {-# OVERLAPPING #-} PGTyped (PGTypeOf ty1)

215+instance (HasUnique tab (Join outer from) row, Has col row ty)

199− => HasParameter 1 (ty1:tys) ty1

216+ => IsLabel col (Expression outer commons 'Ungrouped schemas params from ty) where

200−instance {-# OVERLAPPABLE #-} (KnownNat n, HasParameter (n-1) params ty)

217+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)

201− => HasParameter n (ty' : params) ty

218+instance (HasUnique tab (Join outer from) row, Has col row ty, tys ~ '[ty])

202−

219+ => IsLabel col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where

203−instance (HasUnique relation relations columns, Has column columns ty)

220+ fromLabel = fromLabel @col :* Nil

221+instance (HasUnique tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))

222+ => IsLabel col

223+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where

224+ fromLabel = fromLabel @col `As` Alias

225+instance (HasUnique tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])

226+ => IsLabel col

227+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where

228+ fromLabel = fromLabel @col :* Nil

229+

230+instance (Has tab (Join outer from) row, Has col row ty)

231+ => IsQualified tab col (Expression outer commons 'Ungrouped schemas params from ty) where

232+ tab ! col = UnsafeExpression $

233+ renderSQL tab <> "." <> renderSQL col

234+instance (Has tab (Join outer from) row, Has col row ty, tys ~ '[ty])

235+ => IsQualified tab col (NP (Expression outer commons 'Ungrouped schemas params from) tys) where

236+ tab ! col = tab ! col :* Nil

237+instance (Has tab (Join outer from) row, Has col row ty, column ~ (col ::: ty))

238+ => IsQualified tab col

239+ (Aliased (Expression outer commons 'Ungrouped schemas params from) column) where

240+ tab ! col = tab ! col `As` col

241+instance (Has tab (Join outer from) row, Has col row ty, columns ~ '[col ::: ty])

242+ => IsQualified tab col

204− => IsLabel column (Expression relations 'Ungrouped params ty) where

243+ (NP (Aliased (Expression outer commons 'Ungrouped schemas params from)) columns) where

205− fromLabel = UnsafeExpression $ renderAlias (Alias @column)

244+ tab ! col = tab ! col :* Nil

206

245

207−instance (Has relation relations columns, Has column columns ty)

208− => IsQualified relation column (Expression relations 'Ungrouped params ty) where

209− relation ! column = UnsafeExpression $

210− renderAlias relation <> "." <> renderAlias column

211−

212instance

246instance

213− ( HasUnique relation relations columns

247+ ( HasUnique tab (Join outer from) row

214− , Has column columns ty

248+ , Has col row ty

215− , GroupedBy relation column bys

249+ , GroupedBy tab col bys

216− ) => IsLabel column

250+ ) => IsLabel col

217− (Expression relations ('Grouped bys) params ty) where

251+ (Expression outer commons ('Grouped bys) schemas params from ty) where

218− fromLabel = UnsafeExpression $ renderAlias (Alias @column)

252+ fromLabel = UnsafeExpression $ renderSQL (Alias @col)

219−

220instance

253instance

221− ( Has relation relations columns

254+ ( HasUnique tab (Join outer from) row

222− , Has column columns ty

255+ , Has col row ty

223− , GroupedBy relation column bys

256+ , GroupedBy tab col bys

224− ) => IsQualified relation column

257+ , tys ~ '[ty]

258+ ) => IsLabel col

225− (Expression relations ('Grouped bys) params ty) where

259+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where

226− relation ! column = UnsafeExpression $

260+ fromLabel = fromLabel @col :* Nil

227− renderAlias relation <> "." <> renderAlias column

261+instance

228−

262+ ( HasUnique tab (Join outer from) row

229−-- | analagous to `Nothing`

263+ , Has col row ty

230−--

264+ , GroupedBy tab col bys

231−-- >>> renderExpression $ null_

265+ , column ~ (col ::: ty)

232−-- "NULL"

266+ ) => IsLabel col

233−null_ :: Expression relations grouping params ('Null ty)

267+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where

234−null_ = UnsafeExpression "NULL"

268+ fromLabel = fromLabel @col `As` Alias

235−

269+instance

236−-- | analagous to `Just`

270+ ( HasUnique tab (Join outer from) row

237−--

271+ , Has col row ty

238−-- >>> renderExpression $ unNull true

272+ , GroupedBy tab col bys

239−-- "TRUE"

273+ , columns ~ '[col ::: ty]

240−unNull

274+ ) => IsLabel col

241− :: Expression relations grouping params ('NotNull ty)

275+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where

242− -- ^ not @NULL@

276+ fromLabel = fromLabel @col :* Nil

243− -> Expression relations grouping params ('Null ty)

244−unNull = UnsafeExpression . renderExpression

245−

246−-- | return the leftmost value which is not NULL

247−--

248−-- >>> renderExpression $ coalesce [null_, unNull true] false

249−-- "COALESCE(NULL, TRUE, FALSE)"

250−coalesce

251− :: [Expression relations grouping params ('Null ty)]

252− -- ^ @NULL@s may be present

253− -> Expression relations grouping params ('NotNull ty)

254− -- ^ @NULL@ is absent

255− -> Expression relations grouping params ('NotNull ty)

256−coalesce nullxs notNullx = UnsafeExpression $

257− "COALESCE" <> parenthesized (commaSeparated

258− ((renderExpression <$> nullxs) <> [renderExpression notNullx]))

259−

260−-- | analagous to `Data.Maybe.fromMaybe` using @COALESCE@

261−--

262−-- >>> renderExpression $ fromNull true null_

263−-- "COALESCE(NULL, TRUE)"

264−fromNull

265− :: Expression relations grouping params ('NotNull ty)

266− -- ^ what to convert @NULL@ to

267− -> Expression relations grouping params ('Null ty)

268− -> Expression relations grouping params ('NotNull ty)

269−fromNull notNullx nullx = coalesce [nullx] notNullx

270−

271−-- | >>> renderExpression $ null_ & isNull

272−-- "NULL IS NULL"

273−isNull

274− :: Expression relations grouping params ('Null ty)

275− -- ^ possibly @NULL@

276− -> Condition relations grouping params

277−isNull x = UnsafeExpression $ renderExpression x <+> "IS NULL"

278−

279−-- | >>> renderExpression $ null_ & isn'tNull

280−-- "NULL IS NOT NULL"

281−isn'tNull

282− :: Expression relations grouping params ('Null ty)

283− -- ^ possibly @NULL@

284− -> Condition relations grouping params

285−isn'tNull x = UnsafeExpression $ renderExpression x <+> "IS NOT NULL"

286−

287−-- | analagous to `maybe` using @IS NULL@

288−--

289−-- >>> renderExpression $ matchNull true not_ null_

290−-- "CASE WHEN NULL IS NULL THEN TRUE ELSE (NOT NULL) END"

291−matchNull

292− :: Expression relations grouping params (nullty)

293− -- ^ what to convert @NULL@ to

294− -> ( Expression relations grouping params ('NotNull ty)

295− -> Expression relations grouping params (nullty) )

296− -- ^ function to perform when @NULL@ is absent

297− -> Expression relations grouping params ('Null ty)

298− -> Expression relations grouping params (nullty)

299−matchNull y f x = ifThenElse (isNull x) y

300− (f (UnsafeExpression (renderExpression x)))

301−

302−-- | right inverse to `fromNull`, if its arguments are equal then

303−-- `nullIf` gives @NULL@.

304−--

305−-- >>> :set -XTypeApplications -XDataKinds

306−-- >>> renderExpression @_ @_ @'[_] $ fromNull false (nullIf false (param @1))

307−-- "COALESCE(NULL IF (FALSE, ($1 :: bool)), FALSE)"

308−nullIf

309− :: Expression relations grouping params ('NotNull ty)

310− -- ^ @NULL@ is absent

311− -> Expression relations grouping params ('NotNull ty)

312− -- ^ @NULL@ is absent

313− -> Expression relations grouping params ('Null ty)

314−nullIf x y = UnsafeExpression $ "NULL IF" <+> parenthesized

315− (renderExpression x <> ", " <> renderExpression y)

316−

317−-- | >>> renderExpression $ array [null_, unNull false, unNull true]

318−-- "ARRAY[NULL, FALSE, TRUE]"

319−array

320− :: [Expression relations grouping params ('Null ty)]

321− -- ^ array elements

322− -> Expression relations grouping params (nullity ('PGvararray ty))

323−array xs = UnsafeExpression $

324− "ARRAY[" <> commaSeparated (renderExpression <$> xs) <> "]"

325−

326−instance Monoid

327− (Expression relations grouping params (nullity ('PGvararray ty))) where

328− mempty = array []

329− mappend = unsafeBinaryOp "||"

330−

331−-- | >>> renderExpression @_ @_ @'[_] $ greatest currentTimestamp [param @1]

332−-- "GREATEST(CURRENT_TIMESTAMP, ($1 :: timestamp with time zone))"

333−greatest

334− :: Expression relations grouping params (nullty)

335− -- ^ needs at least 1 argument

336− -> [Expression relations grouping params (nullty)]

337− -- ^ or more

338− -> Expression relations grouping params (nullty)

339−greatest x xs = UnsafeExpression $ "GREATEST("

340− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

341−

342−-- | >>> renderExpression $ least currentTimestamp [null_]

343−-- "LEAST(CURRENT_TIMESTAMP, NULL)"

344−least

345− :: Expression relations grouping params (nullty)

346− -- ^ needs at least 1 argument

347− -> [Expression relations grouping params (nullty)]

348− -- ^ or more

349− -> Expression relations grouping params (nullty)

350−least x xs = UnsafeExpression $ "LEAST("

351− <> commaSeparated (renderExpression <$> (x:xs)) <> ")"

352

277

278+instance

279+ ( Has tab (Join outer from) row

280+ , Has col row ty

281+ , GroupedBy tab col bys

282+ ) => IsQualified tab col

283+ (Expression outer commons ('Grouped bys) schemas params from ty) where

284+ tab ! col = UnsafeExpression $

285+ renderSQL tab <> "." <> renderSQL col

286+instance

287+ ( Has tab (Join outer from) row

288+ , Has col row ty

289+ , GroupedBy tab col bys

290+ , tys ~ '[ty]

291+ ) => IsQualified tab col

292+ (NP (Expression outer commons ('Grouped bys) schemas params from) tys) where

293+ tab ! col = tab ! col :* Nil

294+instance

295+ ( Has tab (Join outer from) row

296+ , Has col row ty

297+ , GroupedBy tab col bys

298+ , column ~ (col ::: ty)

299+ ) => IsQualified tab col

300+ (Aliased (Expression outer commons ('Grouped bys) schemas params from) column) where

301+ tab ! col = tab ! col `As` col

302+instance

303+ ( Has tab (Join outer from) row

304+ , Has col row ty

305+ , GroupedBy tab col bys

306+ , columns ~ '[col ::: ty]

307+ ) => IsQualified tab col

308+ (NP (Aliased (Expression outer commons ('Grouped bys) schemas params from)) columns) where

309+ tab ! col = tab ! col :* Nil

310+

311+instance (KnownSymbol label, label `In` labels) => IsPGlabel label

312+ (Expression outer commons grp schemas params from (null ('PGenum labels))) where

313+ label = UnsafeExpression $ renderSQL (PGlabel @label)

314+

353−-- | >>> renderExpression $ unsafeBinaryOp "OR" true false

315+-- | >>> printSQL $ unsafeBinaryOp "OR" true false

354−-- "(TRUE OR FALSE)"

316+-- (TRUE OR FALSE)

355−unsafeBinaryOp

317+unsafeBinaryOp :: ByteString -> Operator ty0 ty1 ty2

356− :: ByteString

357− -- ^ operator

358− -> Expression relations grouping params (ty0)

359− -> Expression relations grouping params (ty1)

360− -> Expression relations grouping params (ty2)

361unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

318unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

362− renderExpression x <+> op <+> renderExpression y

319+ renderSQL x <+> op <+> renderSQL y

363−

320+

364−-- | >>> renderExpression $ unsafeUnaryOp "NOT" true

321+binaryOp

322+ :: forall op sch schemas schema x y z.

323+ ( Has sch schemas schema

324+ , Has op schema ('Operator ('BinaryOp x y z)) )

325+ => OperatorDB schemas x y z

326+binaryOp = unsafeBinaryOp $ renderSymbol @op

327+

328+-- | >>> printSQL $ unsafeLeftOp "NOT" true

365−-- "(NOT TRUE)"

329+-- (NOT TRUE)

366−unsafeUnaryOp

367− :: ByteString

330+unsafeLeftOp :: ByteString -> x --> y

368− -- ^ operator

331+unsafeLeftOp op x = UnsafeExpression $ parenthesized $ op <+> renderSQL x

369− -> Expression relations grouping params (ty0)

332+

370− -> Expression relations grouping params (ty1)

333+leftOp

334+ :: forall op sch schemas schema x y.

335+ ( Has sch schemas schema

336+ , Has op schema ('Operator ('LeftOp x y)) )

337+ => FunctionDB schemas x y

338+leftOp = unsafeLeftOp $ renderSymbol @op

339+

340+-- | >>> printSQL $ true & unsafeRightOp "IS NOT TRUE"

341+-- (TRUE IS NOT TRUE)

342+unsafeRightOp :: ByteString -> x --> y

371−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $

343+unsafeRightOp op x = UnsafeExpression $ parenthesized $ renderSQL x <+> op

372− op <+> renderExpression x

344+

373−

345+rightOp

346+ :: forall op sch schemas schema x y.

347+ ( Has sch schemas schema

348+ , Has op schema ('Operator ('RightOp x y)) )

349+ => FunctionDB schemas x y

350+rightOp = unsafeRightOp $ renderSymbol @op

351+

374−-- | >>> renderExpression $ unsafeFunction "f" true

352+-- | >>> printSQL $ unsafeFunction "f" true

375−-- "f(TRUE)"

353+-- f(TRUE)

376−unsafeFunction

354+unsafeFunction :: ByteString -> x --> y

377− :: ByteString

378− -- ^ function

379− -> Expression relations grouping params (xty)

380− -> Expression relations grouping params (yty)

381unsafeFunction fun x = UnsafeExpression $

355unsafeFunction fun x = UnsafeExpression $

382− fun <> parenthesized (renderExpression x)

356+ fun <> parenthesized (renderSQL x)

383−

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+

384−instance PGNum ty

378+instance ty `In` PGNum

385− => Num (Expression relations grouping params (nullity ty)) where

379+ => Num (Expression outer commons grp schemas params from (null ty)) where

386 (+) = unsafeBinaryOp "+"

380 (+) = unsafeBinaryOp "+"

387 (-) = unsafeBinaryOp "-"

381 (-) = unsafeBinaryOp "-"

388 (*) = unsafeBinaryOp "*"

382 (*) = unsafeBinaryOp "*"

@@ -393,19 +387,24 @@ instance PGNum ty

393 . fromString

387 . fromString

394 . show

388 . show

395

389

396−instance (PGNum ty, PGFloating ty) => Fractional

390+instance (ty `In` PGNum, ty `In` PGFloating) => Fractional

397− (Expression relations grouping params (nullity ty)) where

391+ (Expression outer commons grp schemas params from (null ty)) where

398 (/) = unsafeBinaryOp "/"

392 (/) = unsafeBinaryOp "/"

399− fromRational x = fromInteger (numerator x) / fromInteger (denominator x)

393+ fromRational

394+ = UnsafeExpression

395+ . fromString

396+ . ($ "")

397+ . showFFloat Nothing

398+ . fromRat @Double

400

399

401−instance (PGNum ty, PGFloating ty) => Floating

400+instance (ty `In` PGNum, ty `In` PGFloating) => Floating

402− (Expression relations grouping params (nullity ty)) where

401+ (Expression outer commons grp schemas params from (null ty)) where

403 pi = UnsafeExpression "pi()"

402 pi = UnsafeExpression "pi()"

404 exp = unsafeFunction "exp"

403 exp = unsafeFunction "exp"

405 log = unsafeFunction "ln"

404 log = unsafeFunction "ln"

406 sqrt = unsafeFunction "sqrt"

405 sqrt = unsafeFunction "sqrt"

407 b ** x = UnsafeExpression $

406 b ** x = UnsafeExpression $

408− "power(" <> renderExpression b <> ", " <> renderExpression x <> ")"

407+ "power(" <> renderSQL b <> ", " <> renderSQL x <> ")"

409 logBase b y = log y / log b

408 logBase b y = log y / log b

410 sin = unsafeFunction "sin"

409 sin = unsafeFunction "sin"

411 cos = unsafeFunction "cos"

410 cos = unsafeFunction "cos"

@@ -420,756 +419,54 @@ instance (PGNum ty, PGFloating ty) => Floating

420 acosh x = log (x + sqrt (x*x - 1))

419 acosh x = log (x + sqrt (x*x - 1))

421 atanh x = log ((1 + x) / (1 - x)) / 2

420 atanh x = log ((1 + x) / (1 - x)) / 2

422

421

423−-- | >>> :{

422+-- | Contained by operators

424−-- let

423+class PGSubset ty where

425−-- expression :: Expression relations grouping params (nullity 'PGfloat4)

424+ (@>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

426−-- expression = atan2_ pi 2

425+ (@>) = unsafeBinaryOp "@>"

427−-- in renderExpression expression

426+ (<@) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

428−-- :}

427+ (<@) = unsafeBinaryOp "<@"

429−-- "atan2(pi(), 2)"

428+instance PGSubset 'PGjsonb

430−atan2_

429+instance PGSubset 'PGtsquery

431− :: PGFloating float

430+instance PGSubset ('PGvararray ty)

432− => Expression relations grouping params (nullity float)

431+instance PGSubset ('PGrange ty)

433− -- ^ numerator

432+

434− -> Expression relations grouping params (nullity float)

433+class PGIntersect ty where

435− -- ^ denominator

434+ (@&&) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

436− -> Expression relations grouping params (nullity float)

435+ (@&&) = unsafeBinaryOp "&&"

437−atan2_ y x = UnsafeExpression $

436+instance PGIntersect ('PGvararray ty)

438− "atan2(" <> renderExpression y <> ", " <> renderExpression x <> ")"

437+instance PGIntersect ('PGrange ty)

439−

440−-- When a `cast` is applied to an `Expression` of a known type, it

441−-- represents a run-time type conversion. The cast will succeed only if a

442−-- suitable type conversion operation has been defined.

443−--

444−-- | >>> renderExpression $ true & cast int4

445−-- "(TRUE :: int4)"

446−cast

447− :: TypeExpression ty1

448− -- ^ type to cast as

449− -> Expression relations grouping params (nullity ty0)

450− -- ^ value to convert

451− -> Expression relations grouping params (nullity ty1)

452−cast ty x = UnsafeExpression $ parenthesized $

453− renderExpression x <+> "::" <+> renderTypeExpression ty

454−

455−-- | integer division, truncates the result

456−--

457−-- >>> :{

458−-- let

459−-- expression :: Expression relations grouping params (nullity 'PGint2)

460−-- expression = 5 `quot_` 2

461−-- in renderExpression expression

462−-- :}

463−-- "(5 / 2)"

464−quot_

465− :: PGIntegral int

466− => Expression relations grouping params (nullity int)

467− -- ^ numerator

468− -> Expression relations grouping params (nullity int)

469− -- ^ denominator

470− -> Expression relations grouping params (nullity int)

471−quot_ = unsafeBinaryOp "/"

472−

473−-- | remainder upon integer division

474−--

475−-- >>> :{

476−-- let

477−-- expression :: Expression relations grouping params (nullity 'PGint2)

478−-- expression = 5 `rem_` 2

479−-- in renderExpression expression

480−-- :}

481−-- "(5 % 2)"

482−rem_

483− :: PGIntegral int

484− => Expression relations grouping params (nullity int)

485− -- ^ numerator

486− -> Expression relations grouping params (nullity int)

487− -- ^ denominator

488− -> Expression relations grouping params (nullity int)

489−rem_ = unsafeBinaryOp "%"

490−

491−-- | >>> :{

492−-- let

493−-- expression :: Expression relations grouping params (nullity 'PGfloat4)

494−-- expression = trunc pi

495−-- in renderExpression expression

496−-- :}

497−-- "trunc(pi())"

498−trunc

499− :: PGFloating frac

500− => Expression relations grouping params (nullity frac)

501− -- ^ fractional number

502− -> Expression relations grouping params (nullity frac)

503−trunc = unsafeFunction "trunc"

504−

505−-- | >>> :{

506−-- let

507−-- expression :: Expression relations grouping params (nullity 'PGfloat4)

508−-- expression = round_ pi

509−-- in renderExpression expression

510−-- :}

511−-- "round(pi())"

512−round_

513− :: PGFloating frac

514− => Expression relations grouping params (nullity frac)

515− -- ^ fractional number

516− -> Expression relations grouping params (nullity frac)

517−round_ = unsafeFunction "round"

518−

519−-- | >>> :{

520−-- let

521−-- expression :: Expression relations grouping params (nullity 'PGfloat4)

522−-- expression = ceiling_ pi

523−-- in renderExpression expression

524−-- :}

525−-- "ceiling(pi())"

526−ceiling_

527− :: PGFloating frac

528− => Expression relations grouping params (nullity frac)

529− -- ^ fractional number

530− -> Expression relations grouping params (nullity frac)

531−ceiling_ = unsafeFunction "ceiling"

532−

533−-- | A `Condition` is a boolean valued `Expression`. While SQL allows

534−-- conditions to have @NULL@, Squeal instead chooses to disallow @NULL@,

535−-- forcing one to handle the case of @NULL@ explicitly to produce

536−-- a `Condition`.

537−type Condition relations grouping params =

538− Expression relations grouping params ('NotNull 'PGbool)

539−

540−-- | >>> renderExpression true

541−-- "TRUE"

542−true :: Condition relations grouping params

543−true = UnsafeExpression "TRUE"

544−

545−-- | >>> renderExpression false

546−-- "FALSE"

547−false :: Condition relations grouping params

548−false = UnsafeExpression "FALSE"

549−

550−-- | >>> renderExpression $ not_ true

551−-- "(NOT TRUE)"

552−not_

553− :: Condition relations grouping params

554− -> Condition relations grouping params

555−not_ = unsafeUnaryOp "NOT"

556−

557−-- | >>> renderExpression $ true .&& false

558−-- "(TRUE AND FALSE)"

559−(.&&)

560− :: Condition relations grouping params

561− -> Condition relations grouping params

562− -> Condition relations grouping params

563−(.&&) = unsafeBinaryOp "AND"

564−

565−-- | >>> renderExpression $ true .|| false

566−-- "(TRUE OR FALSE)"

567−(.||)

568− :: Condition relations grouping params

569− -> Condition relations grouping params

570− -> Condition relations grouping params

571−(.||) = unsafeBinaryOp "OR"

572−

573−-- | >>> :{

574−-- let

575−-- expression :: Expression relations grouping params (nullity 'PGint2)

576−-- expression = caseWhenThenElse [(true, 1), (false, 2)] 3

577−-- in renderExpression expression

578−-- :}

579−-- "CASE WHEN TRUE THEN 1 WHEN FALSE THEN 2 ELSE 3 END"

580−caseWhenThenElse

581− :: [ ( Condition relations grouping params

582− , Expression relations grouping params (ty)

583− ) ]

584− -- ^ whens and thens

585− -> Expression relations grouping params (ty)

586− -- ^ else

587− -> Expression relations grouping params (ty)

588−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat

589− [ "CASE"

590− , mconcat

591− [ mconcat

592− [ " WHEN ", renderExpression when_

593− , " THEN ", renderExpression then_

594− ]

595− | (when_,then_) <- whenThens

596− ]

597− , " ELSE ", renderExpression else_

598− , " END"

599− ]

600−

601−-- | >>> :{

602−-- let

603−-- expression :: Expression relations grouping params (nullity 'PGint2)

604−-- expression = ifThenElse true 1 0

605−-- in renderExpression expression

606−-- :}

607−-- "CASE WHEN TRUE THEN 1 ELSE 0 END"

608−ifThenElse

609− :: Condition relations grouping params

610− -> Expression relations grouping params (ty) -- ^ then

611− -> Expression relations grouping params (ty) -- ^ else

612− -> Expression relations grouping params (ty)

613−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_

614−

615−-- | Comparison operations like `.==`, `./=`, `.>`, `.>=`, `.<` and `.<=`

616−-- will produce @NULL@s if one of their arguments is @NULL@.

617−--

618−-- >>> renderExpression $ unNull true .== null_

619−-- "(TRUE = NULL)"

620−(.==)

621− :: Expression relations grouping params (nullity ty) -- ^ lhs

622− -> Expression relations grouping params (nullity ty) -- ^ rhs

623− -> Expression relations grouping params (nullity 'PGbool)

624−(.==) = unsafeBinaryOp "="

625−infix 4 .==

626−

627−-- | >>> renderExpression $ unNull true ./= null_

628−-- "(TRUE <> NULL)"

629−(./=)

630− :: Expression relations grouping params (nullity ty) -- ^ lhs

631− -> Expression relations grouping params (nullity ty) -- ^ rhs

632− -> Expression relations grouping params (nullity 'PGbool)

633−(./=) = unsafeBinaryOp "<>"

634−infix 4 ./=

635−

636−-- | >>> renderExpression $ unNull true .>= null_

637−-- "(TRUE >= NULL)"

638−(.>=)

639− :: Expression relations grouping params (nullity ty) -- ^ lhs

640− -> Expression relations grouping params (nullity ty) -- ^ rhs

641− -> Expression relations grouping params (nullity 'PGbool)

642−(.>=) = unsafeBinaryOp ">="

643−infix 4 .>=

644−

645−-- | >>> renderExpression $ unNull true .< null_

646−-- "(TRUE < NULL)"

647−(.<)

648− :: Expression relations grouping params (nullity ty) -- ^ lhs

649− -> Expression relations grouping params (nullity ty) -- ^ rhs

650− -> Expression relations grouping params (nullity 'PGbool)

651−(.<) = unsafeBinaryOp "<"

652−infix 4 .<

653−

654−-- | >>> renderExpression $ unNull true .<= null_

655−-- "(TRUE <= NULL)"

656−(.<=)

657− :: Expression relations grouping params (nullity ty) -- ^ lhs

658− -> Expression relations grouping params (nullity ty) -- ^ rhs

659− -> Expression relations grouping params (nullity 'PGbool)

660−(.<=) = unsafeBinaryOp "<="

661−infix 4 .<=

662−

663−-- | >>> renderExpression $ unNull true .> null_

664−-- "(TRUE > NULL)"

665−(.>)

666− :: Expression relations grouping params (nullity ty) -- ^ lhs

667− -> Expression relations grouping params (nullity ty) -- ^ rhs

668− -> Expression relations grouping params (nullity 'PGbool)

669−(.>) = unsafeBinaryOp ">"

670−infix 4 .>

671−

672−-- | >>> renderExpression currentDate

673−-- "CURRENT_DATE"

674−currentDate

675− :: Expression relations grouping params (nullity 'PGdate)

676−currentDate = UnsafeExpression "CURRENT_DATE"

677−

678−-- | >>> renderExpression currentTime

679−-- "CURRENT_TIME"

680−currentTime

681− :: Expression relations grouping params (nullity 'PGtimetz)

682−currentTime = UnsafeExpression "CURRENT_TIME"

683−

684−-- | >>> renderExpression currentTimestamp

685−-- "CURRENT_TIMESTAMP"

686−currentTimestamp

687− :: Expression relations grouping params (nullity 'PGtimestamptz)

688−currentTimestamp = UnsafeExpression "CURRENT_TIMESTAMP"

689−

690−-- | >>> renderExpression localTime

691−-- "LOCALTIME"

692−localTime

693− :: Expression relations grouping params (nullity 'PGtime)

694−localTime = UnsafeExpression "LOCALTIME"

695−

696−-- | >>> renderExpression localTimestamp

697−-- "LOCALTIMESTAMP"

698−localTimestamp

699− :: Expression relations grouping params (nullity 'PGtimestamp)

700−localTimestamp = UnsafeExpression "LOCALTIMESTAMP"

701−

702−{-----------------------------------------

703−text

704−-----------------------------------------}

705

438

706instance IsString

439instance IsString

707− (Expression relations grouping params (nullity 'PGtext)) where

440+ (Expression outer commons grp schemas params from (null 'PGtext)) where

708 fromString str = UnsafeExpression $

441 fromString str = UnsafeExpression $

709 "E\'" <> fromString (escape =<< str) <> "\'"

442 "E\'" <> fromString (escape =<< str) <> "\'"

710− where

443+instance IsString

711− escape = \case

444+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

712− '\NUL' -> "\\0"

445+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsvector") $

713− '\'' -> "''"

446+ "E\'" <> fromString (escape =<< str) <> "\'"

714− '"' -> "\\\""

447+instance IsString

715− '\b' -> "\\b"

448+ (Expression outer commons grp schemas params from (null 'PGtsquery)) where

716− '\n' -> "\\n"

449+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsquery") $

717− '\r' -> "\\r"

450+ "E\'" <> fromString (escape =<< str) <> "\'"

718− '\t' -> "\\t"

451+

719− '\\' -> "\\\\"

452+instance Semigroup

720− c -> [c]

453+ (Expression outer commons grp schemas params from (null ('PGvararray ty))) where

454+ (<>) = unsafeBinaryOp "||"

455+instance Semigroup

456+ (Expression outer commons grp schemas params from (null 'PGjsonb)) where

457+ (<>) = unsafeBinaryOp "||"

458+instance Semigroup

459+ (Expression outer commons grp schemas params from (null 'PGtext)) where

460+ (<>) = unsafeBinaryOp "||"

461+instance Semigroup

462+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

463+ (<>) = unsafeBinaryOp "||"

721

464

722instance Monoid

465instance Monoid

723− (Expression relations grouping params (nullity 'PGtext)) where

466+ (Expression outer commons grp schemas params from (null 'PGtext)) where

724 mempty = fromString ""

467 mempty = fromString ""

725− mappend = unsafeBinaryOp "||"

468+ mappend = (<>)

726−

469+instance Monoid

727−-- | >>> renderExpression $ lower "ARRRGGG"

470+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

728−-- "lower(E'ARRRGGG')"

471+ mempty = fromString ""

729−lower

472+ mappend = (<>)

730− :: Expression relations grouping params (nullity 'PGtext)

731− -- ^ string to lower case

732− -> Expression relations grouping params (nullity 'PGtext)

733−lower = unsafeFunction "lower"

734−

735−-- | >>> renderExpression $ upper "eeee"

736−-- "upper(E'eeee')"

737−upper

738− :: Expression relations grouping params (nullity 'PGtext)

739− -- ^ string to upper case

740− -> Expression relations grouping params (nullity 'PGtext)

741−upper = unsafeFunction "upper"

742−

743−-- | >>> renderExpression $ charLength "four"

744−-- "char_length(E'four')"

745−charLength

746− :: Expression relations grouping params (nullity 'PGtext)

747− -- ^ string to measure

748− -> Expression relations grouping params (nullity 'PGint4)

749−charLength = unsafeFunction "char_length"

750−

751−-- | The `like` expression returns true if the @string@ matches

752−-- the supplied @pattern@. If @pattern@ does not contain percent signs

753−-- or underscores, then the pattern only represents the string itself;

754−-- in that case `like` acts like the equals operator. An underscore (_)

755−-- in pattern stands for (matches) any single character; a percent sign (%)

756−-- matches any sequence of zero or more characters.

757−--

758−-- >>> renderExpression $ "abc" `like` "a%"

759−-- "(E'abc' LIKE E'a%')"

760−like

761− :: Expression relations grouping params (nullity 'PGtext)

762− -- ^ string

763− -> Expression relations grouping params (nullity 'PGtext)

764− -- ^ pattern

765− -> Expression relations grouping params (nullity 'PGbool)

766−like = unsafeBinaryOp "LIKE"

767−

768−{-----------------------------------------

769−aggregation

770−-----------------------------------------}

771−

772−-- | escape hatch to define aggregate functions

773−unsafeAggregate

774− :: ByteString -- ^ aggregate function

775− -> Expression relations 'Ungrouped params (xty)

776− -> Expression relations ('Grouped bys) params (yty)

777−unsafeAggregate fun x = UnsafeExpression $ mconcat

778− [fun, "(", renderExpression x, ")"]

779−

780−-- | escape hatch to define aggregate functions over distinct values

781−unsafeAggregateDistinct

782− :: ByteString -- ^ aggregate function

783− -> Expression relations 'Ungrouped params (xty)

784− -> Expression relations ('Grouped bys) params (yty)

785−unsafeAggregateDistinct fun x = UnsafeExpression $ mconcat

786− [fun, "(DISTINCT ", renderExpression x, ")"]

787−

788−-- | >>> :{

789−-- let

790−-- expression :: Expression '[tab ::: '["col" ::: 'Null 'PGnumeric]] ('Grouped bys) params ('Null 'PGnumeric)

791−-- expression = sum_ #col

792−-- in renderExpression expression

793−-- :}

794−-- "sum(\"col\")"

795−sum_

796− :: PGNum ty

797− => Expression relations 'Ungrouped params (nullity ty)

798− -- ^ what to sum

799− -> Expression relations ('Grouped bys) params (nullity ty)

800−sum_ = unsafeAggregate "sum"

801−

802−-- | >>> :{

803−-- let

804−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGnumeric]] ('Grouped bys) params (nullity 'PGnumeric)

805−-- expression = sumDistinct #col

806−-- in renderExpression expression

807−-- :}

808−-- "sum(DISTINCT \"col\")"

809−sumDistinct

810− :: PGNum ty

811− => Expression relations 'Ungrouped params (nullity ty)

812− -- ^ what to sum

813− -> Expression relations ('Grouped bys) params (nullity ty)

814−sumDistinct = unsafeAggregateDistinct "sum"

815−

816−-- | A constraint for `PGType`s that you can take averages of and the resulting

817−-- `PGType`.

818−class PGAvg ty avg | ty -> avg where

819− avg, avgDistinct

820− :: Expression relations 'Ungrouped params (nullity ty)

821− -- ^ what to average

822− -> Expression relations ('Grouped bys) params (nullity avg)

823− avg = unsafeAggregate "avg"

824− avgDistinct = unsafeAggregateDistinct "avg"

825−instance PGAvg 'PGint2 'PGnumeric

826−instance PGAvg 'PGint4 'PGnumeric

827−instance PGAvg 'PGint8 'PGnumeric

828−instance PGAvg 'PGnumeric 'PGnumeric

829−instance PGAvg 'PGfloat4 'PGfloat8

830−instance PGAvg 'PGfloat8 'PGfloat8

831−instance PGAvg 'PGinterval 'PGinterval

832−

833−-- | >>> :{

834−-- let

835−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

836−-- expression = bitAnd #col

837−-- in renderExpression expression

838−-- :}

839−-- "bit_and(\"col\")"

840−bitAnd

841− :: PGIntegral int

842− => Expression relations 'Ungrouped params (nullity int)

843− -- ^ what to aggregate

844− -> Expression relations ('Grouped bys) params (nullity int)

845−bitAnd = unsafeAggregate "bit_and"

846−

847−-- | >>> :{

848−-- let

849−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

850−-- expression = bitOr #col

851−-- in renderExpression expression

852−-- :}

853−-- "bit_or(\"col\")"

854−bitOr

855− :: PGIntegral int

856− => Expression relations 'Ungrouped params (nullity int)

857− -- ^ what to aggregate

858− -> Expression relations ('Grouped bys) params (nullity int)

859−bitOr = unsafeAggregate "bit_or"

860−

861−-- | >>> :{

862−-- let

863−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

864−-- expression = bitAndDistinct #col

865−-- in renderExpression expression

866−-- :}

867−-- "bit_and(DISTINCT \"col\")"

868−bitAndDistinct

869− :: PGIntegral int

870− => Expression relations 'Ungrouped params (nullity int)

871− -- ^ what to aggregate

872− -> Expression relations ('Grouped bys) params (nullity int)

873−bitAndDistinct = unsafeAggregateDistinct "bit_and"

874−

875−-- | >>> :{

876−-- let

877−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGint4]] (Grouped bys) params (nullity 'PGint4)

878−-- expression = bitOrDistinct #col

879−-- in renderExpression expression

880−-- :}

881−-- "bit_or(DISTINCT \"col\")"

882−bitOrDistinct

883− :: PGIntegral int

884− => Expression relations 'Ungrouped params (nullity int)

885− -- ^ what to aggregate

886− -> Expression relations ('Grouped bys) params (nullity int)

887−bitOrDistinct = unsafeAggregateDistinct "bit_or"

888−

889−-- | >>> :{

890−-- let

891−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

892−-- expression = boolAnd #col

893−-- in renderExpression expression

894−-- :}

895−-- "bool_and(\"col\")"

896−boolAnd

897− :: Expression relations 'Ungrouped params (nullity 'PGbool)

898− -- ^ what to aggregate

899− -> Expression relations ('Grouped bys) params (nullity 'PGbool)

900−boolAnd = unsafeAggregate "bool_and"

901−

902−-- | >>> :{

903−-- let

904−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

905−-- expression = boolOr #col

906−-- in renderExpression expression

907−-- :}

908−-- "bool_or(\"col\")"

909−boolOr

910− :: Expression relations 'Ungrouped params (nullity 'PGbool)

911− -- ^ what to aggregate

912− -> Expression relations ('Grouped bys) params (nullity 'PGbool)

913−boolOr = unsafeAggregate "bool_or"

914−

915−-- | >>> :{

916−-- let

917−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

918−-- expression = boolAndDistinct #col

919−-- in renderExpression expression

920−-- :}

921−-- "bool_and(DISTINCT \"col\")"

922−boolAndDistinct

923− :: Expression relations 'Ungrouped params (nullity 'PGbool)

924− -- ^ what to aggregate

925− -> Expression relations ('Grouped bys) params (nullity 'PGbool)

926−boolAndDistinct = unsafeAggregateDistinct "bool_and"

927−

928−-- | >>> :{

929−-- let

930−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

931−-- expression = boolOrDistinct #col

932−-- in renderExpression expression

933−-- :}

934−-- "bool_or(DISTINCT \"col\")"

935−boolOrDistinct

936− :: Expression relations 'Ungrouped params (nullity 'PGbool)

937− -- ^ what to aggregate

938− -> Expression relations ('Grouped bys) params (nullity 'PGbool)

939−boolOrDistinct = unsafeAggregateDistinct "bool_or"

940−

941−-- | A special aggregation that does not require an input

942−--

943−-- >>> renderExpression countStar

944−-- "count(*)"

945−countStar

946− :: Expression relations ('Grouped bys) params ('NotNull 'PGint8)

947−countStar = UnsafeExpression $ "count(*)"

948−

949−-- | >>> :{

950−-- let

951−-- expression :: Expression '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

952−-- expression = count #col

953−-- in renderExpression expression

954−-- :}

955−-- "count(\"col\")"

956−count

957− :: Expression relations 'Ungrouped params ty

958− -- ^ what to count

959− -> Expression relations ('Grouped bys) params ('NotNull 'PGint8)

960−count = unsafeAggregate "count"

961−

962−-- | >>> :{

963−-- let

964−-- expression :: Expression '[tab ::: '["col" ::: nullity ty]] (Grouped bys) params ('NotNull 'PGint8)

965−-- expression = countDistinct #col

966−-- in renderExpression expression

967−-- :}

968−-- "count(DISTINCT \"col\")"

969−countDistinct

970− :: Expression relations 'Ungrouped params ty

971− -- ^ what to count

972− -> Expression relations ('Grouped bys) params ('NotNull 'PGint8)

973−countDistinct = unsafeAggregateDistinct "count"

974−

975−-- | synonym for `boolAnd`

976−--

977−-- >>> :{

978−-- let

979−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

980−-- expression = every #col

981−-- in renderExpression expression

982−-- :}

983−-- "every(\"col\")"

984−every

985− :: Expression relations 'Ungrouped params (nullity 'PGbool)

986− -- ^ what to aggregate

987− -> Expression relations ('Grouped bys) params (nullity 'PGbool)

988−every = unsafeAggregate "every"

989−

990−-- | synonym for `boolAndDistinct`

991−--

992−-- >>> :{

993−-- let

994−-- expression :: Expression '[tab ::: '["col" ::: nullity 'PGbool]] (Grouped bys) params (nullity 'PGbool)

995−-- expression = everyDistinct #col

996−-- in renderExpression expression

997−-- :}

998−-- "every(DISTINCT \"col\")"

999−everyDistinct

1000− :: Expression relations 'Ungrouped params (nullity 'PGbool)

1001− -- ^ what to aggregate

1002− -> Expression relations ('Grouped bys) params (nullity 'PGbool)

1003−everyDistinct = unsafeAggregateDistinct "every"

1004−

1005−-- | minimum and maximum aggregation

1006−max_, min_, maxDistinct, minDistinct

1007− :: Expression relations 'Ungrouped params (nullity ty)

1008− -- ^ what to aggregate

1009− -> Expression relations ('Grouped bys) params (nullity ty)

1010−max_ = unsafeAggregate "max"

1011−min_ = unsafeAggregate "min"

1012−maxDistinct = unsafeAggregateDistinct "max"

1013−minDistinct = unsafeAggregateDistinct "min"

1014−

1015−{-----------------------------------------

1016−tables

1017−-----------------------------------------}

1018−

1019−-- | A `Table` from a table expression is a way

1020−-- to call a table reference by its alias.

1021−newtype Table

1022− (schema :: SchemaType)

1023− (columns :: RelationType)

1024− = UnsafeTable { renderTable :: ByteString }

1025− deriving (GHC.Generic,Show,Eq,Ord,NFData)

1026−instance

1027− ( Has alias schema ('Table table)

1028− , relation ~ ColumnsToRelation (TableToColumns table)

1029− ) => IsLabel alias (Table schema relation) where

1030− fromLabel = UnsafeTable $ renderAlias (Alias @alias)

1031−

1032−-- | A `View` from a table expression is a way

1033−-- to call a table reference by its alias.

1034−newtype View

1035− (schema :: SchemaType)

1036− (columns :: RelationType)

1037− = UnsafeView { renderView :: ByteString }

1038− deriving (GHC.Generic,Show,Eq,Ord,NFData)

1039−instance

1040− ( Has alias schema ('View columns)

1041− ) => IsLabel alias (View schema columns) where

1042− fromLabel = UnsafeView $ renderAlias (Alias @alias)

1043−

1044−{-----------------------------------------

1045−type expressions

1046−-----------------------------------------}

1047−

1048−-- | `TypeExpression`s are used in `cast`s and `createTable` commands.

1049−newtype TypeExpression (ty :: PGType)

1050− = UnsafeTypeExpression { renderTypeExpression :: ByteString }

1051− deriving (GHC.Generic,Show,Eq,Ord,NFData)

1052−

1053−-- | logical Boolean (true/false)

1054−bool :: TypeExpression 'PGbool

1055−bool = UnsafeTypeExpression "bool"

1056−-- | signed two-byte integer

1057−int2, smallint :: TypeExpression 'PGint2

1058−int2 = UnsafeTypeExpression "int2"

1059−smallint = UnsafeTypeExpression "smallint"

1060−-- | signed four-byte integer

1061−int4, int, integer :: TypeExpression 'PGint4

1062−int4 = UnsafeTypeExpression "int4"

1063−int = UnsafeTypeExpression "int"

1064−integer = UnsafeTypeExpression "integer"

1065−-- | signed eight-byte integer

1066−int8, bigint :: TypeExpression 'PGint8

1067−int8 = UnsafeTypeExpression "int8"

1068−bigint = UnsafeTypeExpression "bigint"

1069−-- | arbitrary precision numeric type

1070−numeric :: TypeExpression 'PGnumeric

1071−numeric = UnsafeTypeExpression "numeric"

1072−-- | single precision floating-point number (4 bytes)

1073−float4, real :: TypeExpression 'PGfloat4

1074−float4 = UnsafeTypeExpression "float4"

1075−real = UnsafeTypeExpression "real"

1076−-- | double precision floating-point number (8 bytes)

1077−float8, doublePrecision :: TypeExpression 'PGfloat8

1078−float8 = UnsafeTypeExpression "float8"

1079−doublePrecision = UnsafeTypeExpression "double precision"

1080−-- | variable-length character string

1081−text :: TypeExpression 'PGtext

1082−text = UnsafeTypeExpression "text"

1083−-- | fixed-length character string

1084−char, character

1085− :: (KnownNat n, 1 <= n)

1086− => proxy n

1087− -> TypeExpression ('PGchar n)

1088−char p = UnsafeTypeExpression $ "char(" <> renderNat p <> ")"

1089−character p = UnsafeTypeExpression $ "character(" <> renderNat p <> ")"

1090−-- | variable-length character string

1091−varchar, characterVarying

1092− :: (KnownNat n, 1 <= n)

1093− => proxy n

1094− -> TypeExpression ('PGvarchar n)

1095−varchar p = UnsafeTypeExpression $ "varchar(" <> renderNat p <> ")"

1096−characterVarying p = UnsafeTypeExpression $

1097− "character varying(" <> renderNat p <> ")"

1098−-- | binary data ("byte array")

1099−bytea :: TypeExpression 'PGbytea

1100−bytea = UnsafeTypeExpression "bytea"

1101−-- | date and time (no time zone)

1102−timestamp :: TypeExpression 'PGtimestamp

1103−timestamp = UnsafeTypeExpression "timestamp"

1104−-- | date and time, including time zone

1105−timestampWithTimeZone :: TypeExpression 'PGtimestamptz

1106−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"

1107−-- | calendar date (year, month, day)

1108−date :: TypeExpression 'PGdate

1109−date = UnsafeTypeExpression "date"

1110−-- | time of day (no time zone)

1111−time :: TypeExpression 'PGtime

1112−time = UnsafeTypeExpression "time"

1113−-- | time of day, including time zone

1114−timeWithTimeZone :: TypeExpression 'PGtimetz

1115−timeWithTimeZone = UnsafeTypeExpression "time with time zone"

1116−-- | time span

1117−interval :: TypeExpression 'PGinterval

1118−interval = UnsafeTypeExpression "interval"

1119−-- | universally unique identifier

1120−uuid :: TypeExpression 'PGuuid

1121−uuid = UnsafeTypeExpression "uuid"

1122−-- | IPv4 or IPv6 host address

1123−inet :: TypeExpression 'PGinet

1124−inet = UnsafeTypeExpression "inet"

1125−-- | textual JSON data

1126−json :: TypeExpression 'PGjson

1127−json = UnsafeTypeExpression "json"

1128−-- | binary JSON data, decomposed

1129−jsonb :: TypeExpression 'PGjsonb

1130−jsonb = UnsafeTypeExpression "jsonb"

1131−-- | variable length array

1132−vararray

1133− :: TypeExpression pg

1134− -> TypeExpression ('PGvararray pg)

1135−vararray ty = UnsafeTypeExpression $ renderTypeExpression ty <> "[]"

1136−-- | fixed length array

1137−--

1138−-- >>> renderTypeExpression (fixarray (Proxy @2) json)

1139−-- "json[2]"

1140−fixarray

1141− :: KnownNat n

1142− => proxy n

1143− -> TypeExpression pg

1144− -> TypeExpression ('PGfixarray n pg)

1145−fixarray p ty = UnsafeTypeExpression $

1146− renderTypeExpression ty <> "[" <> renderNat p <> "]"

1147−

1148−-- | `pgtype` is a demoted version of a `PGType`

1149−class PGTyped (ty :: PGType) where pgtype :: TypeExpression ty

1150−instance PGTyped 'PGbool where pgtype = bool

1151−instance PGTyped 'PGint2 where pgtype = int2

1152−instance PGTyped 'PGint4 where pgtype = int4

1153−instance PGTyped 'PGint8 where pgtype = int8

1154−instance PGTyped 'PGnumeric where pgtype = numeric

1155−instance PGTyped 'PGfloat4 where pgtype = float4

1156−instance PGTyped 'PGfloat8 where pgtype = float8

1157−instance PGTyped 'PGtext where pgtype = text

1158−instance (KnownNat n, 1 <= n)

1159− => PGTyped ('PGchar n) where pgtype = char (Proxy @n)

1160−instance (KnownNat n, 1 <= n)

1161− => PGTyped ('PGvarchar n) where pgtype = varchar (Proxy @n)

1162−instance PGTyped 'PGbytea where pgtype = bytea

1163−instance PGTyped 'PGtimestamp where pgtype = timestamp

1164−instance PGTyped 'PGtimestamptz where pgtype = timestampWithTimeZone

1165−instance PGTyped 'PGdate where pgtype = date

1166−instance PGTyped 'PGtime where pgtype = time

1167−instance PGTyped 'PGtimetz where pgtype = timeWithTimeZone

1168−instance PGTyped 'PGinterval where pgtype = interval

1169−instance PGTyped 'PGuuid where pgtype = uuid

1170−instance PGTyped 'PGjson where pgtype = json

1171−instance PGTyped 'PGjsonb where pgtype = jsonb

1172−instance PGTyped ty => PGTyped ('PGvararray ty) where

1173− pgtype = vararray (pgtype @ty)

1174−instance (KnownNat n, PGTyped ty) => PGTyped ('PGfixarray n ty) where

1175− pgtype = fixarray (Proxy @n) (pgtype @ty)

squeal-postgresql/src/Squeal/PostgreSQL/Expression/Aggregate.hsnew file+462

@@ -0,0 +1,462 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression.Aggregate

3+Description: Aggregate functions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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+423−357

@@ -9,316 +9,371 @@ Squeal data manipulation language.

9-}

11{-# LANGUAGE

12− DataKinds

13− , DeriveDataTypeable

14− , DeriveGeneric

12+ DeriveGeneric

15 , FlexibleContexts

13 , FlexibleContexts

14+ , FlexibleInstances

16 , GADTs

15 , GADTs

17 , GeneralizedNewtypeDeriving

16 , GeneralizedNewtypeDeriving

18− , KindSignatures

19 , LambdaCase

17 , LambdaCase

18+ , MultiParamTypeClasses

20 , OverloadedStrings

19 , OverloadedStrings

20+ , PatternSynonyms

21+ , QuantifiedConstraints

21 , RankNTypes

22 , RankNTypes

22− , StandaloneDeriving

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeFamilies

23 , TypeInType

26 , TypeInType

24 , TypeOperators

27 , TypeOperators

28+ , UndecidableInstances

25#-}

29#-}

27module Squeal.PostgreSQL.Manipulation

31module Squeal.PostgreSQL.Manipulation

28 ( -- * Manipulation

32 ( -- * Manipulation

33+ Manipulation_

29− Manipulation (UnsafeManipulation, renderManipulation)

34+ , Manipulation (..)

30 , queryStatement

35 , queryStatement

31− , ColumnValue (..)

32− , ReturningClause (ReturningStar, Returning)

33− , ConflictClause (OnConflictDoRaise, OnConflictDoNothing, OnConflictDoUpdate)

34 -- * Insert

36 -- * Insert

35− , insertRows

37+ , insertInto

36− , insertRow

38+ , insertInto_

37− , insertRows_

38− , insertRow_

39− , insertQuery

40− , insertQuery_

41− , renderReturningClause

42− , renderConflictClause

43 -- * Update

39 -- * Update

44 , update

40 , update

45 , update_

41 , update_

46 -- * Delete

42 -- * Delete

47 , deleteFrom

43 , deleteFrom

48 , deleteFrom_

44 , deleteFrom_

49− -- * With

45+ -- * Clauses

50− , with

46+ , Optional (..)

47+ , QueryClause (..)

48+ , pattern Values_

49+ , ReturningClause (..)

50+ , pattern Returning_

51+ , ConflictClause (..)

52+ , ConflictTarget (..)

53+ , ConflictAction (..)

54+ , UsingClause (..)

51 ) where

55 ) where

53import Control.DeepSeq

57import Control.DeepSeq

54import Data.ByteString hiding (foldr)

58import Data.ByteString hiding (foldr)

55−import Data.Monoid

59+import Data.Kind (Type)

57−import qualified Data.ByteString as ByteString

58import qualified Generics.SOP as SOP

61import qualified Generics.SOP as SOP

59import qualified GHC.Generics as GHC

62import qualified GHC.Generics as GHC

64+import Squeal.PostgreSQL.Alias

61import Squeal.PostgreSQL.Expression

65import Squeal.PostgreSQL.Expression

66+import Squeal.PostgreSQL.Expression.Logic

67+import Squeal.PostgreSQL.List

68+import Squeal.PostgreSQL.PG

62import Squeal.PostgreSQL.Render

69import Squeal.PostgreSQL.Render

63import Squeal.PostgreSQL.Query

70import Squeal.PostgreSQL.Query

64import Squeal.PostgreSQL.Schema

71import Squeal.PostgreSQL.Schema

73+-- $setup

74+-- >>> import Squeal.PostgreSQL

75+-- >>> import Data.Int

76+-- >>> import Data.Time

77+

66{- |

78{- |

67A `Manipulation` is a statement which may modify data in the database,

79A `Manipulation` is a statement which may modify data in the database,

68−but does not alter the schema. Examples are inserts, updates and deletes.

80+but does not alter its schemas. Examples are inserts, updates and deletes.

69A `Query` is also considered a `Manipulation` even though it does not modify data.

81A `Query` is also considered a `Manipulation` even though it does not modify data.

83+The general `Manipulation` type is parameterized by

84+

85+* @commons :: FromType@ - scope for all `common` table expressions,

86+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

87+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

88+* @row :: RowType@ - return type of the `Query`.

89+-}

90+newtype Manipulation

91+ (commons :: FromType)

92+ (schemas :: SchemasType)

93+ (params :: [NullityType])

94+ (columns :: RowType)

95+ = UnsafeManipulation { renderManipulation :: ByteString }

96+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

97+instance RenderSQL (Manipulation commons schemas params columns) where

98+ renderSQL = renderManipulation

99+instance With Manipulation where

100+ with Done manip = manip

101+ with ctes manip = UnsafeManipulation $

102+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL manip

103+

104+{- |

105+The top level `Manipulation_` type is parameterized by a @schemas@ `SchemasType`,

106+against which the query is type-checked, an input @parameters@ Haskell `Type`,

107+and an ouput row Haskell `Type`.

108+

109+A top-level `Manipulation_` can be run

110+using `Squeal.PostgreSQL.PQ.manipulateParams`, or if @parameters = ()@

111+using `Squeal.PostgreSQL.PQ.manipulate`.

112+

113+Generally, @parameters@ will be a Haskell tuple or record whose entries

114+may be referenced using positional

115+`Squeal.PostgreSQL.Expression.Parameter.parameter`s and @row@ will be a

116+Haskell record, whose entries will be targeted using overloaded labels.

117+

118+>>> :set -XDeriveAnyClass -XDerivingStrategies

119+>>> :{

120+data Row a b = Row { col1 :: a, col2 :: b }

121+ deriving stock (GHC.Generic)

122+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

123+:}

124+

71simple insert:

125simple insert:

126

127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]

128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

73>>> :{

129>>> :{

74let

130let

75− manipulation :: Manipulation

131+ manipulation :: Manipulation_ (Public Schema) () ()

76− '[ "tab" ::: 'Table ('[] :=>

77− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

78− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[] '[]

79 manipulation =

132 manipulation =

80− insertRow_ #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)

133+ insertInto_ #tab (Values_ (Set 2 `as` #col1 :* Default `as` #col2))

81−in renderManipulation manipulation

134+in printSQL manipulation

82:}

135:}

83−"INSERT INTO \"tab\" (\"col1\", \"col2\") VALUES (2, DEFAULT);"

136+INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)

137

85parameterized insert:

138parameterized insert:

139

140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

87>>> :{

142>>> :{

88let

143let

89− manipulation :: Manipulation

144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()

90− '[ "tab" ::: 'Table ('[] :=>

91− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

92− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

93− '[ 'NotNull 'PGint4, 'NotNull 'PGint4 ] '[]

94 manipulation =

145 manipulation =

95− insertRow_ #tab

96− (Set (param @1) `As` #col1 :* Set (param @2) `As` #col2 :* Nil)

146+ insertInto_ #tab (Values_ (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2))

97−in renderManipulation manipulation

147+in printSQL manipulation

98:}

148:}

99−"INSERT INTO \"tab\" (\"col1\", \"col2\") VALUES (($1 :: int4), ($2 :: int4));"

149+INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))

100

150

101returning insert:

151returning insert:

102

152

103>>> :{

153>>> :{

104let

154let

105− manipulation :: Manipulation

155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)

106− '[ "tab" ::: 'Table ('[] :=>

107− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

108− , "col2" ::: 'Def :=> 'NotNull 'PGint4 ])] '[]

109− '["fromOnly" ::: 'NotNull 'PGint4]

110 manipulation =

156 manipulation =

111− insertRow #tab (Set 2 `As` #col1 :* Default `As` #col2 :* Nil)

157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))

112− OnConflictDoRaise (Returning (#col1 `As` #fromOnly :* Nil))

158+ OnConflictDoRaise (Returning (#col1 `as` #fromOnly))

113−in renderManipulation manipulation

159+in printSQL manipulation

114:}

160:}

115−"INSERT INTO \"tab\" (\"col1\", \"col2\") VALUES (2, DEFAULT) RETURNING \"col1\" AS \"fromOnly\";"

161+INSERT INTO "tab" ("col1", "col2") VALUES (2, 3) RETURNING "col1" AS "fromOnly"

116

162

117upsert:

163upsert:

118

164

165+>>> type CustomersColumns = '["name" ::: 'NoDef :=> 'NotNull 'PGtext, "email" ::: 'NoDef :=> 'NotNull 'PGtext]

166+>>> type CustomersConstraints = '["uq" ::: 'Unique '["name"]]

167+>>> type CustomersSchema = '["customers" ::: 'Table (CustomersConstraints :=> CustomersColumns)]

119>>> :{

168>>> :{

120let

169let

121− manipulation :: Manipulation

170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()

122− '[ "tab" ::: 'Table ('[] :=>

123− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

124− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

125− '[] '[ "sum" ::: 'NotNull 'PGint4]

126 manipulation =

171 manipulation =

127− insertRows #tab

172+ insertInto #customers

128− (Set 2 `As` #col1 :* Set 4 `As` #col2 :* Nil)

173+ (Values_ (Set "John Smith" `as` #name :* Set "john@smith.com" `as` #email))

129− [Set 6 `As` #col1 :* Set 8 `As` #col2 :* Nil]

174+ (OnConflict (OnConstraint #uq)

130− (OnConflictDoUpdate

175+ (DoUpdate (Set (#excluded ! #email <> "; " <> #customers ! #email) `as` #email) []))

131− (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

176+ (Returning_ Nil)

132− [#col1 .== #col2])

133− (Returning $ (#col1 + #col2) `As` #sum :* Nil)

134−in renderManipulation manipulation

177+in printSQL manipulation

135:}

178:}

136−"INSERT INTO \"tab\" (\"col1\", \"col2\") VALUES (2, 4), (6, 8) ON CONFLICT DO UPDATE SET \"col1\" = 2 WHERE (\"col1\" = \"col2\") RETURNING (\"col1\" + \"col2\") AS \"sum\";"

179+INSERT INTO "customers" ("name", "email") VALUES (E'John Smith', E'john@smith.com') ON CONFLICT ON CONSTRAINT "uq" DO UPDATE SET "email" = ("excluded"."email" || (E'; ' || "customers"."email"))

137

180

138query insert:

181query insert:

139

182

140>>> :{

183>>> :{

141let

184let

142− manipulation :: Manipulation

185+ manipulation :: Manipulation_ (Public Schema) () ()

143− '[ "tab" ::: 'Table ('[] :=>

186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))

144− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

145− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

146− ])

147− , "other_tab" ::: 'Table ('[] :=>

148− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

149− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4

150− ])

151− ] '[] '[]

152− manipulation =

153− insertQuery_ #tab

154− (selectStar (from (table (#other_tab `As` #t))))

155−in renderManipulation manipulation

187+in printSQL manipulation

156:}

188:}

157−"INSERT INTO \"tab\" SELECT * FROM \"other_tab\" AS \"t\";"

189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"

158

190

159update:

191update:

160

192

161>>> :{

193>>> :{

162let

194let

163− manipulation :: Manipulation

195+ manipulation :: Manipulation_ (Public Schema) () ()

164− '[ "tab" ::: 'Table ('[] :=>

165− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

166− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[] '[]

167− manipulation =

168− update_ #tab (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)

169− (#col1 ./= #col2)

170−in renderManipulation manipulation

197+in printSQL manipulation

171:}

198:}

172−"UPDATE \"tab\" SET \"col1\" = 2 WHERE (\"col1\" <> \"col2\");"

199+UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")

173

200

174delete:

201delete:

175

202

176>>> :{

203>>> :{

177let

204let

178− manipulation :: Manipulation

205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)

179− '[ "tab" ::: 'Table ('[] :=>

206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)

180− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

207+in printSQL manipulation

181− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])] '[]

208+:}

182− '[ "col1" ::: 'NotNull 'PGint4

209+DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *

183− , "col2" ::: 'NotNull 'PGint4 ]

210+

184− manipulation = deleteFrom #tab (#col1 .== #col2) ReturningStar

211+delete and using clause:

212+

213+>>> :{

214+type Schema3 =

215+ '[ "tab" ::: 'Table ('[] :=> Columns)

216+ , "other_tab" ::: 'Table ('[] :=> Columns)

217+ , "third_tab" ::: 'Table ('[] :=> Columns) ]

218+:}

219+

220+>>> :{

221+let

222+ manipulation :: Manipulation_ (Public Schema3) () ()

223+ manipulation =

224+ deleteFrom #tab (Using (table #other_tab & also (table #third_tab)))

225+ ( (#tab ! #col2 .== #other_tab ! #col2)

226+ .&& (#tab ! #col2 .== #third_tab ! #col2) )

227+ (Returning_ Nil)

228+in printSQL manipulation

229+:}

230+DELETE FROM "tab" USING "other_tab" AS "other_tab", "third_tab" AS "third_tab" WHERE (("tab"."col2" = "other_tab"."col2") AND ("tab"."col2" = "third_tab"."col2"))

231+

232+with manipulation:

233+

234+>>> type ProductsColumns = '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

235+>>> type ProductsSchema = '["products" ::: 'Table ('[] :=> ProductsColumns), "products_deleted" ::: 'Table ('[] :=> ProductsColumns)]

236+>>> :{

237+let

238+ manipulation :: Manipulation_ (Public ProductsSchema) (Only Day) ()

239+ manipulation = with

240+ (deleteFrom #products NoUsing (#date .< param @1) (Returning Star) `as` #del)

241+ (insertInto_ #products_deleted (Subquery (select Star (from (common #del)))))

185−in renderManipulation manipulation

242+in printSQL manipulation

186:}

243:}

187−"DELETE FROM \"tab\" WHERE (\"col1\" = \"col2\") RETURNING *;"

244+WITH "del" AS (DELETE FROM "products" WHERE ("date" < ($1 :: date)) RETURNING *) INSERT INTO "products_deleted" SELECT * FROM "del" AS "del"

188-}

245-}

189−newtype Manipulation

246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where

190− (schema :: SchemaType)

247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)

191− (params :: [NullityType])

192− (columns :: RelationType)

193− = UnsafeManipulation { renderManipulation :: ByteString }

194− deriving (GHC.Generic,Show,Eq,Ord,NFData)

195

248

196-- | Convert a `Query` into a `Manipulation`.

249-- | Convert a `Query` into a `Manipulation`.

197queryStatement

250queryStatement

198− :: Query schema params columns

251+ :: Query '[] commons schemas params columns

252+ -- ^ `Query` to embed as a `Manipulation`

199− -> Manipulation schema params columns

253+ -> Manipulation commons schemas params columns

200−queryStatement q = UnsafeManipulation $ renderQuery q <> ";"

254+queryStatement q = UnsafeManipulation $ renderSQL q

201

255

202{-----------------------------------------

256{-----------------------------------------

203INSERT statements

257INSERT statements

204-----------------------------------------}

258-----------------------------------------}

205

259

206−-- | Insert multiple rows.

260+{- |

207−--

208−-- When a table is created, it contains no data. The first thing to do

261+When a table is created, it contains no data. The first thing to do

209−-- before a database can be of much use is to insert data. Data is

262+before a database can be of much use is to insert data. Data is

210−-- conceptually inserted one row at a time. Of course you can also insert

263+conceptually inserted one row at a time. Of course you can also insert

211−-- more than one row, but there is no way to insert less than one row.

264+more than one row, but there is no way to insert less than one row.

212−-- Even if you know only some column values, a complete row must be created.

265+Even if you know only some column values, a complete row must be created.

213−insertRows

266+-}

214− :: ( SOP.SListI columns

267+insertInto

215− , SOP.SListI results

268+ :: ( Has sch schemas schema

216− , Has tab schema ('Table table)

217− , columns ~ TableToColumns table )

218− => Alias tab -- ^ table to insert into

219− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert

220− -> [NP (Aliased (ColumnValue '[] params)) columns] -- ^ more rows to insert

221− -> ConflictClause columns params

222− -- ^ what to do in case of constraint conflict

223− -> ReturningClause columns params results -- ^ results to return

224− -> Manipulation schema params results

225−insertRows tab row rows conflict returning = UnsafeManipulation $

226− "INSERT" <+> "INTO" <+> renderAlias tab

227− <+> parenthesized (renderCommaSeparated renderAliasPart row)

228− <+> "VALUES"

229− <+> commaSeparated

230− ( parenthesized

231− . renderCommaSeparated renderColumnValuePart <$> row:rows )

232− <> renderConflictClause conflict

233− <> renderReturningClause returning

234− where

235− renderAliasPart, renderColumnValuePart

236− :: Aliased (ColumnValue '[] params) ty -> ByteString

237− renderAliasPart (_ `As` name) = renderAlias name

238− renderColumnValuePart (value `As` _) = case value of

239− Default -> "DEFAULT"

240− Set expression -> renderExpression expression

241−

242−-- | Insert a single row.

243−insertRow

244− :: ( SOP.SListI columns

245− , SOP.SListI results

246− , Has tab schema ('Table table)

247− , columns ~ TableToColumns table )

248− => Alias tab -- ^ table to insert into

249− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert

250− -> ConflictClause columns params

251− -- ^ what to do in case of constraint conflict

252− -> ReturningClause columns params results -- ^ results to return

253− -> Manipulation schema params results

254−insertRow tab row = insertRows tab row []

255−

256−-- | Insert multiple rows returning `Nil` and raising an error on conflicts.

257−insertRows_

258− :: ( SOP.SListI columns

259− , Has tab schema ('Table table)

260− , columns ~ TableToColumns table )

261− => Alias tab -- ^ table to insert into

262− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert

263− -> [NP (Aliased (ColumnValue '[] params)) columns] -- ^ more rows to insert

264− -> Manipulation schema params '[]

265−insertRows_ tab row rows =

266− insertRows tab row rows OnConflictDoRaise (Returning Nil)

267−

268−-- | Insert a single row returning `Nil` and raising an error on conflicts.

269−insertRow_

270− :: ( SOP.SListI columns

271− , Has tab schema ('Table table)

272− , columns ~ TableToColumns table )

273− => Alias tab -- ^ table to insert into

274− -> NP (Aliased (ColumnValue '[] params)) columns -- ^ row to insert

275− -> Manipulation schema params '[]

276−insertRow_ tab row = insertRow tab row OnConflictDoRaise (Returning Nil)

277−

278−-- | Insert a `Query`.

279−insertQuery

280− :: ( SOP.SListI columns

281− , SOP.SListI results

282 , Has tab schema ('Table table)

269 , Has tab schema ('Table table)

283− , 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

284− => Alias tab -- ^ table to insert into

277+ -- ^ what to insert

285− -> Query schema params (ColumnsToRelation columns)

286− -> ConflictClause columns params

278+ -> ConflictClause tab commons schemas params table

287− -- ^ what to do in case of constraint conflict

279+ -- ^ what to do in case of conflict

288− -> ReturningClause columns params results -- ^ results to return

280+ -> ReturningClause commons schemas params '[tab ::: row0] row1

281+ -- ^ what to return

289− -> Manipulation schema params results

282+ -> Manipulation commons schemas params row1

290−insertQuery tab query conflict returning = UnsafeManipulation $

283+insertInto tab qry conflict ret = UnsafeManipulation $

291− "INSERT" <+> "INTO" <+> renderAlias tab

284+ "INSERT" <+> "INTO" <+> renderSQL tab

292− <+> renderQuery query

285+ <+> renderSQL qry

293− <> renderConflictClause conflict

286+ <> renderSQL conflict

294− <> renderReturningClause returning

287+ <> renderSQL ret

295−

288+

296−-- | Insert a `Query` returning `Nil` and raising an error on conflicts.

289+-- | Like `insertInto` but with `OnConflictDoRaise` and `no` `ReturningClause`.

297−insertQuery_

290+insertInto_

298− :: ( SOP.SListI columns

291+ :: ( Has sch schemas schema

299 , Has tab schema ('Table table)

292 , Has tab schema ('Table table)

300− , columns ~ TableToColumns table )

293+ , columns ~ TableToColumns table

301− => Alias tab -- ^ table to insert into

294+ , row ~ TableToRow table

302− -> 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

303− -> Manipulation schema params '[]

300+ -> Manipulation commons schemas params '[]

304−insertQuery_ tab query =

301+insertInto_ tab qry =

305− insertQuery tab query OnConflictDoRaise (Returning Nil)

302+ insertInto tab qry OnConflictDoRaise (Returning_ Nil)

306−

303+

307−-- | `ColumnValue`s are values to insert or update in a row

304+-- | A `QueryClause` describes what to `insertInto` a table.

308−-- `Same` updates with the same value.

305+data QueryClause commons schemas params columns where

309−-- `Default` inserts or updates with the @DEFAULT@ value

306+ Values

310−-- `Set` a value to be an `Expression`, relative to the given

307+ :: SOP.SListI columns

311−-- row for an update, and closed for an insert.

308+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

312−data ColumnValue

309+ -- ^ row of values

313− (columns :: RelationType)

310+ -> [NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns]

314− (params :: [NullityType])

311+ -- ^ additional rows of values

315− (ty :: ColumnType)

312+ -> QueryClause commons schemas params columns

316− where

313+ Select

317− Same :: ColumnValue (column ': columns) params ty

314+ :: SOP.SListI columns

318− Default :: ColumnValue columns params ('Def :=> ty)

315+ => NP (Aliased (Optional (Expression '[] commons grp schemas params from))) columns

319− Set

316+ -- ^ row of values

320− :: (forall table. Expression '[table ::: columns] 'Ungrouped params ty)

317+ -> TableExpression '[] commons grp schemas params from

321− -> ColumnValue columns params (constraint :=> ty)

318+ -- ^ from a table expression

319+ -> QueryClause commons schemas params columns

320+ Subquery

321+ :: ColumnsToRow columns ~ row

322+ => Query '[] commons schemas params row

323+ -- ^ subquery to insert

324+ -> QueryClause commons schemas params columns

325+

326+instance RenderSQL (QueryClause commons schemas params columns) where

327+ renderSQL = \case

328+ Values row0 rows ->

329+ parenthesized (renderCommaSeparated renderSQLPart row0)

330+ <+> "VALUES"

331+ <+> commaSeparated

332+ ( parenthesized

333+ . renderCommaSeparated renderValuePart <$> row0 : rows )

334+ Select row0 tab ->

335+ parenthesized (renderCommaSeparatedMaybe renderSQLPartMaybe row0)

336+ <+> "SELECT"

337+ <+> renderCommaSeparatedMaybe renderValuePartMaybe row0

338+ <+> renderSQL tab

339+ Subquery qry -> renderQuery qry

340+ where

341+ renderSQLPartMaybe, renderValuePartMaybe

342+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

343+ -> Maybe ByteString

344+ renderSQLPartMaybe = \case

345+ Default `As` _ -> Nothing

346+ Set _ `As` name -> Just $ renderSQL name

347+ renderValuePartMaybe = \case

348+ Default `As` _ -> Nothing

349+ Set value `As` _ -> Just $ renderExpression value

350+ renderSQLPart, renderValuePart

351+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

352+ -> ByteString

353+ renderSQLPart (_ `As` name) = renderSQL name

354+ renderValuePart (value `As` _) = renderSQL value

355+

356+-- | `Values_` describes a single `NP` list of `Aliased` `Optional` `Expression`s

357+-- whose `ColumnsType` must match the tables'.

358+pattern Values_

359+ :: SOP.SListI columns

360+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

361+ -- ^ row of values

362+ -> QueryClause commons schemas params columns

363+pattern Values_ vals = Values vals []

364+

365+-- | `Optional` is either `Default` or a value, parameterized by an appropriate

366+-- `ColumnConstraint`.

367+data Optional expr ty where

368+ -- | Use the `Default` value for a column.

369+ Default :: Optional expr ('Def :=> ty)

370+ -- | `Set` a value for a column.

371+ Set :: expr ty -> Optional expr (def :=> ty)

372+

373+instance (forall x. RenderSQL (expr x)) => RenderSQL (Optional expr ty) where

374+ renderSQL = \case

375+ Default -> "DEFAULT"

376+ Set expr -> renderSQL expr

322

377

323-- | A `ReturningClause` computes and return value(s) based

378-- | A `ReturningClause` computes and return value(s) based

324-- on each row actually inserted, updated or deleted. This is primarily

379-- on each row actually inserted, updated or deleted. This is primarily

@@ -326,71 +381,100 @@ data ColumnValue

326-- serial sequence number. However, any expression using the table's columns

381-- serial sequence number. However, any expression using the table's columns

327-- is allowed. Only rows that were successfully inserted or updated or

382-- is allowed. Only rows that were successfully inserted or updated or

328-- deleted will be returned. For example, if a row was locked

383-- deleted will be returned. For example, if a row was locked

329−-- but not updated because an `OnConflictDoUpdate` condition was not satisfied,

384+-- but not updated because an `OnConflict` `DoUpdate` condition was not satisfied,

330−-- the row will not be returned. `ReturningStar` will return all columns

385+-- the row will not be returned. `Returning` `Star` will return all columns

331−-- in the row. Use @Returning Nil@ in the common case where no return

386+-- in the row. Use `Returning` `Nil` in the common case where no return

332-- values are desired.

387-- values are desired.

333−data ReturningClause

388+newtype ReturningClause commons schemas params from row =

334− (columns :: ColumnsType)

389+ Returning (Selection '[] commons 'Ungrouped schemas params from row)

335− (params :: [NullityType])

390+

336− (results :: RelationType)

391+instance RenderSQL (ReturningClause commons schemas params from row) where

337− where

392+ renderSQL = \case

338− ReturningStar

393+ Returning (List Nil) -> ""

339− :: results ~ ColumnsToRelation columns

340− => ReturningClause columns params results

341− Returning

342− :: rel ~ ColumnsToRelation columns

343− => NP (Aliased (Expression '[table ::: rel] 'Ungrouped params)) results

344− -> ReturningClause columns params results

345−

346−-- | Render a `ReturningClause`.

347−renderReturningClause

348− :: SOP.SListI results

349− => ReturningClause params columns results

350− -> ByteString

351−renderReturningClause = \case

352− ReturningStar -> " RETURNING *;"

353− Returning Nil -> ";"

354− Returning results -> " RETURNING"

394+ Returning selection -> " RETURNING" <+> renderSQL selection

355− <+> renderCommaSeparated (renderAliasedAs renderExpression) results <> ";"

395+

396+-- | `Returning` a `List`

397+pattern Returning_

398+ :: SOP.SListI row

399+ => NP (Aliased (Expression '[] commons 'Ungrouped schemas params from)) row

400+ -- ^ row of values

401+ -> ReturningClause commons schemas params from row

402+pattern Returning_ list = Returning (List list)

356

403

357-- | A `ConflictClause` specifies an action to perform upon a constraint

404-- | A `ConflictClause` specifies an action to perform upon a constraint

358-- violation. `OnConflictDoRaise` will raise an error.

405-- violation. `OnConflictDoRaise` will raise an error.

359−-- `OnConflictDoNothing` simply avoids inserting a row.

406+-- `OnConflict` `DoNothing` simply avoids inserting a row.

360−-- `OnConflictDoUpdate` updates the existing row that conflicts with the row

407+-- `OnConflict` `DoUpdate` updates the existing row that conflicts with the row

361-- proposed for insertion.

408-- proposed for insertion.

362−data ConflictClause (columns :: ColumnsType) params where

409+data ConflictClause tab commons schemas params table where

363− OnConflictDoRaise :: ConflictClause columns params

410+ OnConflictDoRaise :: ConflictClause tab commons schemas params table

364− OnConflictDoNothing :: ConflictClause columns params

411+ OnConflict

365− OnConflictDoUpdate

412+ :: ConflictTarget constraints

366− :: NP (Aliased (ColumnValue (ColumnsToRelation columns) params)) columns

413+ -- ^ conflict target

367− -> [Condition '[table ::: ColumnsToRelation columns] 'Ungrouped params]

414+ -> ConflictAction tab commons schemas params columns

415+ -- ^ conflict action

368− -> ConflictClause columns params

416+ -> ConflictClause tab commons schemas params (constraints :=> columns)

369

417

370-- | Render a `ConflictClause`.

418-- | Render a `ConflictClause`.

371−renderConflictClause

419+instance SOP.SListI (TableToColumns table)

372− :: SOP.SListI columns

420+ => RenderSQL (ConflictClause tab commons schemas params table) where

373− => ConflictClause columns params

421+ renderSQL = \case

422+ OnConflictDoRaise -> ""

423+ OnConflict target action -> " ON CONFLICT"

424+ <+> renderSQL target <+> renderSQL action

425+

426+{- |

427+`ConflictAction` specifies an alternative `OnConflict` action.

428+It can be either `DoNothing`, or a `DoUpdate` clause specifying

429+the exact details of the `update` action to be performed in case of a conflict.

430+The `Set` and WHERE `Condition`s in `OnConflict` `DoUpdate` have access to the

431+existing row using the table's name (or an alias), and to rows proposed

432+for insertion using the special @#excluded@ table.

433+`OnConflict` `DoNothing` simply avoids inserting a row as its alternative action.

434+`OnConflict` `DoUpdate` updates the existing row that conflicts

435+with the row proposed for insertion as its alternative action.

436+-}

437+data ConflictAction tab commons schemas params columns where

438+ DoNothing :: ConflictAction tab commons schemas params columns

439+ DoUpdate

440+ :: ( row ~ ColumnsToRow columns

441+ , SOP.SListI columns

442+ , columns ~ (col0 ': cols)

443+ , SOP.All (HasIn columns) subcolumns

444+ , AllUnique subcolumns )

445+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]))) subcolumns

446+ -> [Condition '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]]

447+ -- ^ WHERE `Condition`s

448+ -> ConflictAction tab commons schemas params columns

449+

450+instance RenderSQL (ConflictAction tab commons schemas params columns) where

451+ renderSQL = \case

452+ DoNothing -> "DO NOTHING"

453+ DoUpdate updates whs'

454+ -> "DO UPDATE SET"

455+ <+> renderCommaSeparated renderUpdate updates

456+ <> case whs' of

457+ [] -> ""

458+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

459+

460+renderUpdate

461+ :: (forall x. RenderSQL (expr x))

462+ => Aliased (Optional expr) ty

374 -> ByteString

463 -> ByteString

375−renderConflictClause = \case

464+renderUpdate (expr `As` col) = renderSQL col <+> "=" <+> renderSQL expr

376− OnConflictDoRaise -> ""

465+

377− OnConflictDoNothing -> " ON CONFLICT DO NOTHING"

466+-- | A `ConflictTarget` specifies the constraint violation that triggers a

378− OnConflictDoUpdate updates whs'

467+-- `ConflictAction`.

379− -> " ON CONFLICT DO UPDATE SET"

468+data ConflictTarget constraints where

380− <+> renderCommaSeparatedMaybe renderUpdate updates

469+ OnConstraint

381− <> case whs' of

470+ :: Has con constraints constraint

382− [] -> ""

471+ => Alias con

383− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

472+ -> ConflictTarget constraints

384− where

473+

385− renderUpdate

474+-- | Render a `ConflictTarget`

386− :: Aliased (ColumnValue columns params) column

475+instance RenderSQL (ConflictTarget constraints) where

387− -> Maybe ByteString

476+ renderSQL (OnConstraint con) =

388− renderUpdate = \case

477+ "ON" <+> "CONSTRAINT" <+> renderSQL con

389− Same `As` _ -> Nothing

390− Default `As` column -> Just $

391− renderAlias column <+> "=" <+> "DEFAULT"

392− Set expression `As` column -> Just $

393− renderAlias column <+> "=" <+> renderExpression expression

394

478

395{-----------------------------------------

479{-----------------------------------------

396UPDATE statements

480UPDATE statements

@@ -400,113 +484,95 @@ UPDATE statements

400-- in all rows that satisfy the condition.

484-- in all rows that satisfy the condition.

401update

485update

402 :: ( SOP.SListI columns

486 :: ( SOP.SListI columns

403− , SOP.SListI results

487+ , SOP.SListI row1

488+ , Has sch schemas schema

404 , Has tab schema ('Table table)

489 , Has tab schema ('Table table)

490+ , row0 ~ TableToRow table

405− , columns ~ TableToColumns table )

491+ , columns ~ TableToColumns table

492+ , SOP.All (HasIn columns) subcolumns

493+ , AllUnique subcolumns )

406− => Alias tab -- ^ table to update

494+ => QualifiedAlias sch tab -- ^ table to update

407− -> NP (Aliased (ColumnValue (ColumnsToRelation columns) params)) columns

495+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row0]))) subcolumns

408 -- ^ modified values to replace old values

496 -- ^ modified values to replace old values

409− -> Condition '[tab ::: ColumnsToRelation columns] 'Ungrouped params

497+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row0]

410 -- ^ condition under which to perform update on a row

498 -- ^ condition under which to perform update on a row

411− -> ReturningClause columns params results -- ^ results to return

499+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

412− -> Manipulation schema params results

500+ -> Manipulation commons schemas params row1

413update tab columns wh returning = UnsafeManipulation $

501update tab columns wh returning = UnsafeManipulation $

414 "UPDATE"

502 "UPDATE"

415− <+> renderAlias tab

503+ <+> renderSQL tab

416 <+> "SET"

504 <+> "SET"

417− <+> renderCommaSeparatedMaybe renderUpdate columns

505+ <+> renderCommaSeparated renderUpdate columns

418− <+> "WHERE" <+> renderExpression wh

506+ <+> "WHERE" <+> renderSQL wh

419− <> renderReturningClause returning

507+ <> renderSQL returning

420− where

421− renderUpdate

422− :: Aliased (ColumnValue columns params) column

423− -> Maybe ByteString

424− renderUpdate = \case

425− Same `As` _ -> Nothing

426− Default `As` column -> Just $

427− renderAlias column <+> "=" <+> "DEFAULT"

428− Set expression `As` column -> Just $

429− renderAlias column <+> "=" <+> renderExpression expression

430

508

431-- | Update a row returning `Nil`.

509-- | Update a row returning `Nil`.

432update_

510update_

433 :: ( SOP.SListI columns

511 :: ( SOP.SListI columns

512+ , Has sch schemas schema

434 , Has tab schema ('Table table)

513 , Has tab schema ('Table table)

514+ , row ~ TableToRow table

435− , columns ~ TableToColumns table )

515+ , columns ~ TableToColumns table

516+ , SOP.All (HasIn columns) subcolumns

517+ , AllUnique subcolumns )

436− => Alias tab -- ^ table to update

518+ => QualifiedAlias sch tab -- ^ table to update

437− -> NP (Aliased (ColumnValue (ColumnsToRelation columns) params)) columns

519+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row]))) subcolumns

438 -- ^ modified values to replace old values

520 -- ^ modified values to replace old values

439− -> Condition '[tab ::: ColumnsToRelation columns] 'Ungrouped params

521+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

440 -- ^ condition under which to perform update on a row

522 -- ^ condition under which to perform update on a row

441− -> Manipulation schema params '[]

523+ -> Manipulation commons schemas params '[]

442−update_ tab columns wh = update tab columns wh (Returning Nil)

524+update_ tab columns wh = update tab columns wh (Returning_ Nil)

443

525

444{-----------------------------------------

526{-----------------------------------------

445DELETE statements

527DELETE statements

446-----------------------------------------}

528-----------------------------------------}

447

529

530+-- | Specify additional tables with `Using`

531+-- an `also` list of table expressions, allowing columns

532+-- from other tables to appear in the WHERE condition.

533+-- This is similar to the list of tables that can be specified

534+-- in the FROM Clause of a SELECT statement;

535+-- for example, an alias for the table name can be specified.

536+-- Do not repeat the target table in the `Using` list,

537+-- unless you wish to set up a self-join.

538+-- `NoUsing` if no additional tables are to be used.

539+data UsingClause commons schemas params from where

540+ NoUsing :: UsingClause commons schemas params '[]

541+ Using

542+ :: FromClause '[] commons schemas params from

543+ -- ^ what to use

544+ -> UsingClause commons schemas params from

545+

448−-- | Delete rows of a table.

546+-- | Delete rows from a table.

449deleteFrom

547deleteFrom

450− :: ( SOP.SListI results

548+ :: ( SOP.SListI row1

549+ , Has sch schemas schema

451 , Has tab schema ('Table table)

550 , Has tab schema ('Table table)

551+ , row0 ~ TableToRow table

452 , columns ~ TableToColumns table )

552 , columns ~ TableToColumns table )

453− => Alias tab -- ^ table to delete from

553+ => QualifiedAlias sch tab -- ^ table to delete from

554+ -> UsingClause commons schemas params from

454− -> Condition '[tab ::: ColumnsToRelation columns] 'Ungrouped params

555+ -> Condition '[] commons 'Ungrouped schemas params (tab ::: row0 ': from)

455 -- ^ condition under which to delete a row

556 -- ^ condition under which to delete a row

456− -> ReturningClause columns params results -- ^ results to return

557+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

457− -> Manipulation schema params results

558+ -> Manipulation commons schemas params row1

458−deleteFrom tab wh returning = UnsafeManipulation $

559+deleteFrom tab using wh returning = UnsafeManipulation $

459− "DELETE FROM" <+> renderAlias tab

560+ "DELETE FROM"

460− <+> "WHERE" <+> renderExpression wh

561+ <+> renderSQL tab

461− <> renderReturningClause returning

562+ <> case using of

563+ NoUsing -> ""

564+ Using tables -> " USING" <+> renderSQL tables

565+ <+> "WHERE" <+> renderSQL wh

566+ <> renderSQL returning

462

567

463-- | Delete rows returning `Nil`.

568-- | Delete rows returning `Nil`.

464deleteFrom_

569deleteFrom_

570+ :: ( Has sch schemas schema

465− :: ( Has tab schema ('Table table)

571+ , Has tab schema ('Table table)

572+ , row ~ TableToRow table

466 , columns ~ TableToColumns table )

573 , columns ~ TableToColumns table )

467− => Alias tab -- ^ table to delete from

574+ => QualifiedAlias sch tab -- ^ table to delete from

468− -> Condition '[tab ::: ColumnsToRelation columns] 'Ungrouped params

575+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

469 -- ^ condition under which to delete a row

576 -- ^ condition under which to delete a row

470− -> Manipulation schema params '[]

577+ -> Manipulation commons schemas params '[]

471−deleteFrom_ tab wh = deleteFrom tab wh (Returning Nil)

578+deleteFrom_ tab wh = deleteFrom tab NoUsing wh (Returning_ Nil)

472−

473−{-----------------------------------------

474−WITH statements

475−-----------------------------------------}

476−

477−-- | `with` provides a way to write auxiliary statements for use in a larger statement.

478−-- These statements, which are often referred to as Common Table Expressions or CTEs,

479−-- can be thought of as defining temporary tables that exist just for one statement.

480−--

481−-- >>> type ProductsTable = '[] :=> '["product" ::: 'NoDef :=> 'NotNull 'PGtext, "date" ::: 'Def :=> 'NotNull 'PGdate]

482−--

483−-- >>> :{

484−-- let

485−-- manipulation :: Manipulation '["products" ::: '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 (table (#deleted_rows `As` #t)))))

489−-- in renderManipulation manipulation

490−-- :}

491−-- "WITH \"deleted_rows\" AS (DELETE FROM \"products\" WHERE (\"date\" < ($1 :: date)) RETURNING *) INSERT INTO \"products_deleted\" SELECT * FROM \"deleted_rows\" AS \"t\";"

492−with

493− :: SOP.SListI commons

494− => NP (Aliased (Manipulation schema params)) commons

495− -- ^ common table expressions

496− -> Manipulation (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− let

508− str = renderManipulation common

509− len = ByteString.length str

510− str' = ByteString.take (len - 1) str -- remove ';'

511− in

512− parenthesized str'

squeal-postgresql/src/Squeal/PostgreSQL/Migration.hs+349−219

@@ -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

@@ -29,250 +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 & notNull) `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 & notNull) `As` #user_id :*

60+ notNullable int `as` #user_id :*

56− (text & null') `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− ScopedTypeVariables

94− , OverloadedStrings

95− , DataKinds

125+ DataKinds

126+ , DeriveGeneric

127+ , FlexibleContexts

128+ , FlexibleInstances

96 , GADTs

129 , GADTs

97 , LambdaCase

130 , LambdaCase

98− , PolyKinds

99 , OverloadedLabels

131 , OverloadedLabels

132+ , OverloadedStrings

133+ , PolyKinds

134+ , QuantifiedConstraints

135+ , RankNTypes

100 , TypeApplications

136 , TypeApplications

101− , FlexibleContexts

102 , TypeOperators

137 , TypeOperators

103#-}

138#-}

104

139

105module Squeal.PostgreSQL.Migration

140module Squeal.PostgreSQL.Migration

106 ( -- * Migration

141 ( -- * Migration

107 Migration (..)

142 Migration (..)

108− , migrateUp

143+ , Migratory (..)

109− , migrateDown

144+ , Terminally (..)

110− -- * Aligned lists

145+ , terminally

111− , AlignedList (..)

146+ , pureMigration

112− , single

113− -- * Migration table

114 , MigrationsTable

147 , MigrationsTable

115− , createMigrations

148+ , defaultMain

116− , insertMigration

117− , deleteMigration

118− , selectMigration

119 ) where

149 ) where

120

150

121import Control.Category

151import Control.Category

122import Control.Monad

152import Control.Monad

123−import Control.Monad.Base

153+import Data.ByteString (ByteString)

124−import Control.Monad.Trans.Control

125−import Data.Monoid

154+import Data.Foldable (traverse_)

126−import Generics.SOP (K(..))

127import Data.Function ((&))

155import Data.Function ((&))

156+import Data.List ((\\))

128import Data.Text (Text)

157import Data.Text (Text)

158+import Data.Time (UTCTime)

129−import Prelude hiding (id, (.))

159+import Prelude hiding ((.), id)

160+import System.Environment

161+import UnliftIO (MonadIO (..))

130

162

131−import Squeal.PostgreSQL

163+import qualified Data.Text.IO as Text (putStrLn)

164+import qualified Generics.SOP as SOP

165+import qualified GHC.Generics as GHC

132

166

167+import Squeal.PostgreSQL.Alias

168+import Squeal.PostgreSQL.Binary

169+import Squeal.PostgreSQL.Definition

170+import Squeal.PostgreSQL.Definition.Table

171+import Squeal.PostgreSQL.Definition.Table.Constraint

172+import Squeal.PostgreSQL.Expression.Comparison

173+import Squeal.PostgreSQL.Expression.Parameter

174+import Squeal.PostgreSQL.Expression.Time

175+import Squeal.PostgreSQL.Expression.Type

176+import Squeal.PostgreSQL.List

177+import Squeal.PostgreSQL.Manipulation

178+import Squeal.PostgreSQL.PQ

179+import Squeal.PostgreSQL.Query

180+import Squeal.PostgreSQL.Schema

181+import Squeal.PostgreSQL.Transaction

182+

183+-- | A `Migration` is a named "isomorphism" over a given category.

133−-- | A `Migration` should contain an inverse pair of

184+-- It should contain an inverse pair of `up` and `down`

134−-- `up` and `down` instructions and a unique `name`.

185+-- instructions and a unique `name`.

135−data Migration io schema0 schema1 = Migration

186+data Migration p schemas0 schemas1 = Migration

136 { name :: Text -- ^ The `name` of a `Migration`.

187 { name :: Text -- ^ The `name` of a `Migration`.

137 -- Each `name` in a `Migration` should be unique.

188 -- Each `name` in a `Migration` should be unique.

138− , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.

189+ , up :: p schemas0 schemas1 -- ^ The `up` instruction of a `Migration`.

139− , down :: PQ schema1 schema0 io () -- ^ The `down` instruction of a `Migration`.

190+ , down :: p schemas1 schemas0 -- ^ The `down` instruction of a `Migration`.

191+ } deriving (GHC.Generic)

192+

193+{- |

194+A `Migratory` @p@ is a `Category` for which one can execute or rewind

195+a `Path` of `Migration`s over @p@. This includes the category of pure

196+SQL `Definition`s and the category of impure `Terminally` `PQ` `IO` actions.

197+-}

198+class Category p => Migratory p where

199+

200+ {- |

201+ Run a `Path` of `Migration`s.

202+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

203+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

204+ if not, `up` the `Migration` and insert its `name` in the `MigrationsTable`.

205+ -}

206+ migrateUp

207+ :: Path (Migration p) schemas0 schemas1

208+ -> PQ schemas0 schemas1 IO ()

209+

210+ {- |

211+ Rewind a `Path` of `Migration`s.

212+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

213+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

214+ if so, `down` the `Migration` and delete its `name` in the `MigrationsTable`.

215+ -}

216+ migrateDown

217+ :: Path (Migration p) schemas0 schemas1

218+ -> PQ schemas1 schemas0 IO ()

219+

220+instance Migratory Definition where

221+ migrateUp = migrateUp . cmap pureMigration

222+ migrateDown = migrateDown . cmap pureMigration

223+

224+{- | `Terminally` turns an indexed monad transformer and the monad it transforms

225+into a category by restricting the return type to @()@ and permuting the type variables.

226+This is similar to how applying a monad to @()@ yields a monoid.

227+Since a `Terminally` action has a trivial return value, the only reason

228+to run one is for the side effects, in particular database and other IO effects.

229+-}

230+newtype Terminally trans monad x0 x1 = Terminally

231+ { runTerminally :: trans x0 x1 monad () }

232+ deriving GHC.Generic

233+

234+instance

235+ ( IndexedMonadTransPQ trans

236+ , Monad monad

237+ , forall x0 x1. x0 ~ x1 => Monad (trans x0 x1 monad) )

238+ => Category (Terminally trans monad) where

239+ id = Terminally (return ())

240+ Terminally g . Terminally f = Terminally $ pqThen g f

241+

242+-- | `terminally` ignores the output of a computation, returning @()@ and

243+-- wrapping it up into a `Terminally`. You can lift an action in the base monad

244+-- by using @terminally . lift@.

245+terminally

246+ :: Functor (trans x0 x1 monad)

247+ => trans x0 x1 monad ignore

248+ -> Terminally trans monad x0 x1

249+terminally = Terminally . void

250+

251+-- | A `pureMigration` turns a `Migration` involving only pure SQL

252+-- `Definition`s into a `Migration` that may be combined with arbitrary `IO`.

253+pureMigration

254+ :: Migration Definition schemas0 schemas1

255+ -> Migration (Terminally PQ IO) schemas0 schemas1

256+pureMigration migration = Migration

257+ { name = name migration

258+ , up = terminally . define $ up migration

259+ , down = terminally . define $ down migration

140 }

260 }

141

261

142−-- | An `AlignedList` is a type-aligned list or free category.

262+instance Migratory (Terminally PQ IO) where

143−data AlignedList p x0 x1 where

144− Done :: AlignedList p x x

145− (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2

146−infixr 7 :>>

147−instance Category (AlignedList p) where

148− id = Done

149− (.) list = \case

150− Done -> list

151− step :>> steps -> step :>> (steps >>> list)

152−

153−-- | A `single` step.

154−single :: p x0 x1 -> AlignedList p x0 x1

155−single step = step :>> Done

156−

157−-- | Run `Migration`s by creating the `MigrationsTable`

158−-- if it does not exist and then in a transaction, for each each `Migration`

159−-- query to see if the `Migration` is executed. If not, then

160−-- execute the `Migration` and insert its row in the `MigrationsTable`.

161−migrateUp

162− :: MonadBaseControl IO io

163− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run

164− -> PQ

165− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

166− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

167− io ()

168−migrateUp migration =

169− define createMigrations

170− & pqBind okResult

171− & pqThen (transactionallySchema_ (upMigrations migration))

172− where

173

263

174− upMigrations

264+ migrateUp migration = unsafePQ . transactionally_ $ do

175− :: MonadBaseControl IO io

265+ define createMigrations

176− => AlignedList (Migration io) schema0 schema1

266+ upMigrations migration

177− -> PQ

267+

178− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

268+ where

179− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

269+

180− io ()

270+ upMigrations

271+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

272+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

181− upMigrations = \case

273+ upMigrations = \case

182− Done -> return ()

274+ Done -> return ()

183− step :>> steps -> upMigration step & pqThen (upMigrations steps)

275+ step :>> steps -> upMigration step >> upMigrations steps

184−

276+

185− upMigration

277+ upMigration

186− :: MonadBase IO io

278+ :: Migration (Terminally PQ IO) schemas0 schemas1

187− => Migration io schema0 schema1 -> PQ

279+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

188− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

189− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

190− io ()

191− upMigration step =

280+ upMigration step = do

192− queryExecuted step

281+ executed <- queryExecuted step

193− & pqBind (\ executed ->

282+ unless (executed == 1) $ do

194− if executed == 1 -- up step has already been executed

283+ unsafePQ . runTerminally $ up step

195− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

196− else

197− pqEmbed (up step) -- safely switch schemas

198− & pqThen (manipulateParams insertMigration (Only (name step)))

284+ manipulateParams_ insertMigration (Only (name step))

199− -- insert execution record

285+

200− & pqBind okResult)

201−

202− queryExecuted

286+ queryExecuted

203− :: MonadBase IO io

287+ :: Migration (Terminally PQ IO) schemas0 schemas1

204− => Migration io schema0 schema1 -> PQ

288+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

205− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

206− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

207− io Row

208− queryExecuted step = do

289+ queryExecuted step = do

209− result <- runQueryParams selectMigration (Only (name step))

290+ result <- runQueryParams selectMigration (Only (name step))

210− okResult result

211− ntuples result

291+ ntuples result

212−

292+

213−-- | Rewind `Migration`s by creating the `MigrationsTable`

293+ migrateDown migrations = unsafePQ . transactionally_ $ do

214−-- if it does not exist and then in a transaction, for each each `Migration`

215−-- query to see if the `Migration` is executed. If it is, then

216−-- rewind the `Migration` and delete its row in the `MigrationsTable`.

217−migrateDown

218− :: MonadBaseControl IO io

219− => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind

220− -> PQ

221− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

222− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

223− io ()

224−migrateDown migrations =

225− define createMigrations

294+ define createMigrations

226− & pqBind okResult

227− & pqThen (transactionallySchema_ (downMigrations migrations))

295+ downMigrations migrations

296+

228− where

297+ where

229

298

230− downMigrations

299+ downMigrations

231− :: MonadBaseControl IO io

300+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

232− => AlignedList (Migration io) schema0 schema1 -> PQ

301+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

233− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

234− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

235− io ()

236− downMigrations = \case

302+ downMigrations = \case

237− Done -> return ()

303+ Done -> return ()

238− step :>> steps -> downMigrations steps & pqThen (downMigration step)

304+ step :>> steps -> downMigrations steps >> downMigration step

239−

305+

240− downMigration

306+ downMigration

241− :: MonadBase IO io

307+ :: Migration (Terminally PQ IO) schemas0 schemas1

242− => Migration io schema0 schema1 -> PQ

308+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

243− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

244− ("schema_migrations" ::: 'Table MigrationsTable ': schema0)

245− io ()

246− downMigration step =

309+ downMigration step = do

247− queryExecuted step

310+ executed <- queryExecuted step

248− & pqBind (\ executed ->

311+ unless (executed == 0) $ do

249− if executed == 0 -- up step has not been executed

312+ unsafePQ . runTerminally $ down step

250− then PQ (\ _ -> return (K ())) -- unsafely switch schemas

251− else

252− pqEmbed (down step) -- safely switch schemas

253− & pqThen (manipulateParams deleteMigration (Only (name step)))

313+ manipulateParams_ deleteMigration (Only (name step))

254− -- delete execution record

314+

255− & pqBind okResult)

256−

257− queryExecuted

315+ queryExecuted

258− :: MonadBase IO io

316+ :: Migration (Terminally PQ IO) schemas0 schemas1

259− => Migration io schema0 schema1 -> PQ

317+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

260− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

261− ("schema_migrations" ::: 'Table MigrationsTable ': schema1)

262− io Row

263− queryExecuted step = do

318+ queryExecuted step = do

264− result <- runQueryParams selectMigration (Only (name step))

319+ result <- runQueryParams selectMigration (Only (name step))

265− okResult result

266− ntuples result

320+ ntuples result

267−

321+

268−okResult :: MonadBase IO io => K Result results -> PQ schema schema io ()

322+unsafePQ :: (Functor m) => PQ db0 db1 m x -> PQ db0' db1' m x

269−okResult result = do

323+unsafePQ (PQ pq) = PQ $ fmap (SOP.K . SOP.unK) . pq . SOP.K . SOP.unK

270− status <- resultStatus result

271− when (not (status `elem` [CommandOk, TuplesOk])) $ do

272− errorMessageMaybe <- resultErrorMessage result

273− case errorMessageMaybe of

274− Nothing -> error "migrateDown: unknown error"

275− Just msg -> error ("migrationDown: " <> show msg)

276

324

277-- | The `TableType` for a Squeal migration.

325-- | The `TableType` for a Squeal migration.

278type MigrationsTable =

326type MigrationsTable =

@@ -281,38 +329,120 @@ type MigrationsTable =

281 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

329 , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

282 ]

330 ]

283

331

332+data MigrationRow =

333+ MigrationRow { migrationName :: Text

334+ , migrationTime :: UTCTime }

335+ deriving (GHC.Generic, Show)

336+

337+instance SOP.Generic MigrationRow

338+instance SOP.HasDatatypeInfo MigrationRow

339+

340+type MigrationsSchema = '["schema_migrations" ::: 'Table MigrationsTable]

341+type MigrationsSchemas = Public MigrationsSchema

342+

284-- | Creates a `MigrationsTable` if it does not already exist.

343-- | Creates a `MigrationsTable` if it does not already exist.

285−createMigrations

344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas

286− :: Has "schema_migrations" schema ('Table MigrationsTable)

287− => Definition schema schema

288createMigrations =

345createMigrations =

289 createTableIfNotExists #schema_migrations

346 createTableIfNotExists #schema_migrations

290− ( (text & notNull) `As` #name :*

347+ ( (text & notNullable) `as` #name :*

291− (timestampWithTimeZone & notNull & default_ currentTimestamp)

348+ (timestampWithTimeZone & notNullable & default_ currentTimestamp)

292− `As` #executed_at :* Nil )

349+ `as` #executed_at )

293− ( unique (#name :* Nil) `As` #migrations_unique_name :* Nil )

350+ ( unique #name `as` #migrations_unique_name )

294−

351+

295−-- | Inserts a `Migration` into the `MigrationsTable`

352+-- | Inserts a `Migration` into the `MigrationsTable`, returning

296−insertMigration

353+-- the time at which it was inserted.

297− :: Has "schema_migrations" schema ('Table MigrationsTable)

354+insertMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

298− => Manipulation schema '[ 'NotNull 'PGtext] '[]

299−insertMigration = insertRow_ #schema_migrations

355+insertMigration = insertInto_ #schema_migrations

300− ( Set (param @1) `As` #name :*

301− Default `As` #executed_at :* Nil )

356+ (Values_ (Set (param @1) `as` #name :* Default `as` #executed_at))

302−

357+

303−-- | Deletes a `Migration` from the `MigrationsTable`

358+-- | Deletes a `Migration` from the `MigrationsTable`, returning

359+-- the time at which it was inserted.

304−deleteMigration

360+deleteMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

305− :: Has "schema_migrations" schema ('Table MigrationsTable)

306− => Manipulation schema '[ 'NotNull 'PGtext ] '[]

307deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

361deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

308

362

309-- | Selects a `Migration` from the `MigrationsTable`, returning

363-- | Selects a `Migration` from the `MigrationsTable`, returning

310−-- the time at which it was executed.

364+-- the time at which it was inserted.

311selectMigration

365selectMigration

312− :: Has "schema_migrations" schema ('Table MigrationsTable)

366+ :: Query_ MigrationsSchemas (Only Text) (Only UTCTime)

313− => Query schema '[ 'NotNull 'PGtext ]

314− '[ "executed_at" ::: 'NotNull 'PGtimestamptz ]

315−selectMigration = select

367+selectMigration = select_ (#executed_at `as` #fromOnly)

316− (#executed_at `As` #executed_at :* Nil)

317− ( from (table (#schema_migrations `As` #m))

368+ $ from (table (#schema_migrations))

318− & where_ (#name .== param @1))

369+ & where_ (#name .== param @1)

370+

371+selectMigrations :: Query_ MigrationsSchemas () MigrationRow

372+selectMigrations = select_

373+ (#name `as` #migrationName :* #executed_at `as` #migrationTime)

374+ (from (table #schema_migrations))

375+

376+data MigrateCommand

377+ = MigrateStatus

378+ | MigrateUp

379+ | MigrateDown deriving (GHC.Generic, Show)

380+

381+{- | `defaultMain` creates a simple executable

382+from a connection string and a list of `Migration`s. -}

383+defaultMain

384+ :: Migratory p

385+ => ByteString

386+ -- ^ connection string

387+ -> Path (Migration p) db0 db1

388+ -- ^ migrations

389+ -> IO ()

390+defaultMain connectTo migrations = do

391+ command <- readCommandFromArgs

392+ maybe (pure ()) performCommand command

393+

394+ where

395+

396+ performCommand :: MigrateCommand -> IO ()

397+ performCommand = \case

398+ MigrateStatus -> withConnection connectTo $

399+ suppressNotices >> migrateStatus

400+ MigrateUp -> withConnection connectTo $

401+ suppressNotices & pqThen (migrateUp migrations) & pqThen migrateStatus

402+ MigrateDown -> withConnection connectTo $

403+ suppressNotices & pqThen (migrateDown migrations) & pqThen migrateStatus

404+

405+ migrateStatus :: PQ schema schema IO ()

406+ migrateStatus = unsafePQ $ do

407+ runNames <- getRunMigrationNames

408+ let names = ctoList name migrations

409+ unrunNames = names \\ runNames

410+ liftIO $ displayRunned runNames >> displayUnrunned unrunNames

411+

412+ suppressNotices :: PQ schema schema IO ()

413+ suppressNotices = manipulate_ $

414+ UnsafeManipulation "SET client_min_messages TO WARNING;"

415+

416+ readCommandFromArgs :: IO (Maybe MigrateCommand)

417+ readCommandFromArgs = getArgs >>= \case

418+ ["migrate"] -> pure . Just $ MigrateUp

419+ ["rollback"] -> pure . Just $ MigrateDown

420+ ["status"] -> pure . Just $ MigrateStatus

421+ args -> displayUsage args >> pure Nothing

422+

423+ displayUsage :: [String] -> IO ()

424+ displayUsage args = do

425+ putStrLn $ "Invalid command: \"" <> unwords args <> "\". Use:"

426+ putStrLn "migrate to run all available migrations"

427+ putStrLn "rollback to rollback all available migrations"

428+ putStrLn "status to display migrations run and migrations left to run"

429+

430+ getRunMigrationNames :: (MonadIO m) => PQ db0 db0 m [Text]

431+ getRunMigrationNames =

432+ fmap migrationName <$> (unsafePQ (define createMigrations & pqThen (runQuery selectMigrations)) >>= getRows)

433+

434+ displayListOfNames :: [Text] -> IO ()

435+ displayListOfNames [] = Text.putStrLn " None"

436+ displayListOfNames xs =

437+ let singleName n = Text.putStrLn $ " - " <> n

438+ in traverse_ singleName xs

439+

440+ displayUnrunned :: [Text] -> IO ()

441+ displayUnrunned unrunned =

442+ Text.putStrLn "Migrations left to run:"

443+ >> displayListOfNames unrunned

444+

445+ displayRunned :: [Text] -> IO ()

446+ displayRunned runned =

447+ Text.putStrLn "Migrations already run:"

448+ >> displayListOfNames runned

squeal-postgresql/src/Squeal/PostgreSQL/PG.hsnew file+388

@@ -0,0 +1,388 @@

1+{-|

2+Module: Squeal.PostgreSQL.PG

3+Description: Embedding of Haskell types into Postgres's type system

4+Copyright: (c) Eitan Chatav, 2010

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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+314−217

@@ -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`

@@ -20,15 +20,11 @@ of executing Squeal commands.

21{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}

22{-# LANGUAGE

23− DataKinds

24− , DefaultSignatures

23+ DefaultSignatures

25 , FunctionalDependencies

24 , FunctionalDependencies

26− , PolyKinds

27− , DeriveFunctor

28 , FlexibleContexts

25 , FlexibleContexts

29 , FlexibleInstances

26 , FlexibleInstances

30− , MagicHash

27+ , InstanceSigs

31− , MultiParamTypeClasses

32 , OverloadedStrings

28 , OverloadedStrings

33 , RankNTypes

29 , RankNTypes

34 , ScopedTypeVariables

30 , ScopedTypeVariables

@@ -53,9 +49,7 @@ module Squeal.PostgreSQL.PQ

53 , evalPQ

49 , evalPQ

54 , IndexedMonadTransPQ (..)

50 , IndexedMonadTransPQ (..)

55 , MonadPQ (..)

51 , MonadPQ (..)

56− , PQRun

52+ -- * Results

57− , pqliftWith

58− -- * Result

59 , LibPQ.Result

53 , LibPQ.Result

60 , LibPQ.Row

54 , LibPQ.Row

61 , ntuples

55 , ntuples

@@ -67,22 +61,33 @@ module Squeal.PostgreSQL.PQ

67 , LibPQ.ExecStatus (..)

61 , LibPQ.ExecStatus (..)

68 , resultStatus

62 , resultStatus

69 , resultErrorMessage

63 , resultErrorMessage

64+ , resultErrorCode

65+ -- * Exceptions

66+ , SquealException (..)

67+ , PQState (..)

68+ , okResult

69+ , catchSqueal

70+ , handleSqueal

71+ , trySqueal

70 ) where

72 ) where

72−import Control.Exception.Lifted

74+import Control.Exception (Exception, throw)

73−import Control.Monad.Base

74import Control.Monad.Except

75import Control.Monad.Except

75import Control.Monad.Morph

76import Control.Monad.Morph

76−import Control.Monad.Trans.Control

77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)

77import Data.ByteString (ByteString)

78import Data.ByteString (ByteString)

78import Data.Foldable

79import Data.Foldable

79import Data.Function ((&))

80import Data.Function ((&))

81+import Data.Functor ((<&>))

80import Data.Kind

82import Data.Kind

81−import Data.Monoid

83+import Data.Text (pack, Text)

82import Data.Traversable

84import Data.Traversable

83import Generics.SOP

85import Generics.SOP

86+import PostgreSQL.Binary.Encoding (encodingBytes)

88+import qualified Control.Monad.Fail as Fail

85import qualified Database.PostgreSQL.LibPQ as LibPQ

89import qualified Database.PostgreSQL.LibPQ as LibPQ

90+import qualified PostgreSQL.Binary.Encoding as Encoding

87import Squeal.PostgreSQL.Binary

92import Squeal.PostgreSQL.Binary

88import Squeal.PostgreSQL.Definition

93import Squeal.PostgreSQL.Definition

@@ -95,7 +100,6 @@ import Control.Monad.Trans.Identity

95import Control.Monad.Trans.Reader

100import Control.Monad.Trans.Reader

96import Control.Monad.Trans.Maybe

101import Control.Monad.Trans.Maybe

97import Control.Monad.Trans.Cont

102import Control.Monad.Trans.Cont

98−import Control.Monad.Trans.List

103

100import qualified Control.Monad.Trans.State.Lazy as Lazy

104import qualified Control.Monad.Trans.State.Lazy as Lazy

101import qualified Control.Monad.Trans.State.Strict as Strict

105import qualified Control.Monad.Trans.State.Strict as Strict

@@ -104,6 +108,9 @@ import qualified Control.Monad.Trans.Writer.Strict as Strict

104import qualified Control.Monad.Trans.RWS.Lazy as Lazy

108import qualified Control.Monad.Trans.RWS.Lazy as Lazy

105import qualified Control.Monad.Trans.RWS.Strict as Strict

109import qualified Control.Monad.Trans.RWS.Strict as Strict

106

110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

107{- | Makes a new connection to the database server.

114{- | Makes a new connection to the database server.

108

115

109This function opens a new database connection using the parameters taken

116This function opens a new database connection using the parameters taken

@@ -130,22 +137,22 @@ Note that, for now, squeal doesn't offer any protection from connecting

130with the wrong schema!

137with the wrong schema!

131-}

138-}

132connectdb

139connectdb

133− :: forall schema io

140+ :: forall schemas io

134− . MonadBase IO io

141+ . MonadIO io

135 => ByteString -- ^ conninfo

142 => ByteString -- ^ conninfo

136− -> io (K LibPQ.Connection schema)

143+ -> io (K LibPQ.Connection schemas)

137−connectdb = fmap K . liftBase . LibPQ.connectdb

144+connectdb = fmap K . liftIO . LibPQ.connectdb

138

145

139-- | Closes the connection to the server.

146-- | Closes the connection to the server.

140−finish :: MonadBase IO io => K LibPQ.Connection schema -> io ()

147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()

141−finish = liftBase . LibPQ.finish . unK

148+finish = liftIO . LibPQ.finish . unK

142

149

143-- | Do `connectdb` and `finish` before and after a computation.

150-- | Do `connectdb` and `finish` before and after a computation.

144withConnection

151withConnection

145− :: forall schema0 schema1 io x

152+ :: forall schemas0 schemas1 io x

146− . MonadBaseControl IO io

153+ . MonadUnliftIO io

147 => ByteString

154 => ByteString

148− -> PQ schema0 schema1 io x

155+ -> PQ schemas0 schemas1 io x

149 -> io x

156 -> io x

150withConnection connString action = do

157withConnection connString action = do

151 K x <- bracket (connectdb connString) finish (unPQ action)

158 K x <- bracket (connectdb connString) finish (unPQ action)

@@ -153,47 +160,47 @@ withConnection connString action = do

153

160

154-- | Safely `lowerConnection` to a smaller schema.

161-- | Safely `lowerConnection` to a smaller schema.

155lowerConnection

162lowerConnection

156− :: K LibPQ.Connection (table ': schema)

163+ :: K LibPQ.Connection (schema ': schemas)

157− -> K LibPQ.Connection schema

164+ -> K LibPQ.Connection schemas

158lowerConnection (K conn) = K conn

165lowerConnection (K conn) = K conn

159

166

160-- | We keep track of the schema via an Atkey indexed state monad transformer,

167-- | We keep track of the schema via an Atkey indexed state monad transformer,

161-- `PQ`.

168-- `PQ`.

162newtype PQ

169newtype PQ

163− (schema0 :: SchemaType)

170+ (schemas0 :: SchemasType)

164− (schema1 :: SchemaType)

171+ (schemas1 :: SchemasType)

165 (m :: Type -> Type)

172 (m :: Type -> Type)

166 (x :: Type) =

173 (x :: Type) =

167− PQ { unPQ :: K LibPQ.Connection schema0 -> m (K x schema1) }

174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }

168

175

169−instance Monad m => Functor (PQ schema0 schema1 m) where

176+instance Monad m => Functor (PQ schemas0 schemas1 m) where

170 fmap f (PQ pq) = PQ $ \ conn -> do

177 fmap f (PQ pq) = PQ $ \ conn -> do

171 K x <- pq conn

178 K x <- pq conn

172 return $ K (f x)

179 return $ K (f x)

173

180

174−-- | Run a `PQ` and keep the result and the `Connection`.

181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.

175runPQ

182runPQ

176 :: Functor m

183 :: Functor m

177− => PQ schema0 schema1 m x

184+ => PQ schemas0 schemas1 m x

178− -> K LibPQ.Connection schema0

185+ -> K LibPQ.Connection schemas0

179− -> m (x, K LibPQ.Connection schema1)

186+ -> m (x, K LibPQ.Connection schemas1)

180runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

187runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

181 -- K x <- pq conn

188 -- K x <- pq conn

182 -- return (x, K (unK conn))

189 -- return (x, K (unK conn))

183

190

184−-- | Execute a `PQ` and discard the result but keep the `Connection`.

191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.

185execPQ

192execPQ

186 :: Functor m

193 :: Functor m

187− => PQ schema0 schema1 m x

194+ => PQ schemas0 schemas1 m x

188− -> K LibPQ.Connection schema0

195+ -> K LibPQ.Connection schemas0

189− -> m (K LibPQ.Connection schema1)

196+ -> m (K LibPQ.Connection schemas1)

190execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

197execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

191

198

192−-- | Evaluate a `PQ` and discard the `Connection` but keep the result.

199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.

193evalPQ

200evalPQ

194 :: Functor m

201 :: Functor m

195− => PQ schema0 schema1 m x

202+ => PQ schemas0 schemas1 m x

196− -> K LibPQ.Connection schema0

203+ -> K LibPQ.Connection schemas0

197 -> m x

204 -> m x

198evalPQ (PQ pq) conn = unK <$> pq conn

205evalPQ (PQ pq) conn = unK <$> pq conn

199

206

@@ -201,60 +208,56 @@ evalPQ (PQ pq) conn = unK <$> pq conn

201-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

208-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

202-- An indexed monad transformer transforms a `Monad` into an indexed monad.

209-- An indexed monad transformer transforms a `Monad` into an indexed monad.

203-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

210-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

204−-- support running `Definition`s using `define` and embedding a computation

211+-- support running `Definition`s using `define`.

205−-- in a larger schema using `pqEmbed`.

206class IndexedMonadTransPQ pq where

212class IndexedMonadTransPQ pq where

207

213

208 -- | indexed analog of `<*>`

214 -- | indexed analog of `<*>`

209 pqAp

215 pqAp

210 :: Monad m

216 :: Monad m

211− => pq schema0 schema1 m (x -> y)

217+ => pq schemas0 schemas1 m (x -> y)

212− -> pq schema1 schema2 m x

218+ -> pq schemas1 schemas2 m x

213− -> pq schema0 schema2 m y

219+ -> pq schemas0 schemas2 m y

214

220

215 -- | indexed analog of `join`

221 -- | indexed analog of `join`

216 pqJoin

222 pqJoin

217 :: Monad m

223 :: Monad m

218− => pq schema0 schema1 m (pq schema1 schema2 m y)

224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)

219− -> pq schema0 schema2 m y

225+ -> pq schemas0 schemas2 m y

220 pqJoin pq = pq & pqBind id

226 pqJoin pq = pq & pqBind id

221

227

222 -- | indexed analog of `=<<`

228 -- | indexed analog of `=<<`

223 pqBind

229 pqBind

224 :: Monad m

230 :: Monad m

225− => (x -> pq schema1 schema2 m y)

231+ => (x -> pq schemas1 schemas2 m y)

226− -> pq schema0 schema1 m x

232+ -> pq schemas0 schemas1 m x

227− -> pq schema0 schema2 m y

233+ -> pq schemas0 schemas2 m y

228

234

229 -- | indexed analog of flipped `>>`

235 -- | indexed analog of flipped `>>`

230 pqThen

236 pqThen

231 :: Monad m

237 :: Monad m

232− => pq schema1 schema2 m y

238+ => pq schemas1 schemas2 m y

233− -> pq schema0 schema1 m x

239+ -> pq schemas0 schemas1 m x

234− -> pq schema0 schema2 m y

240+ -> pq schemas0 schemas2 m y

235 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

241 pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

236

242

237 -- | indexed analog of `<=<`

243 -- | indexed analog of `<=<`

238 pqAndThen

244 pqAndThen

239 :: Monad m

245 :: Monad m

240− => (y -> pq schema1 schema2 m z)

246+ => (y -> pq schemas1 schemas2 m z)

241− -> (x -> pq schema0 schema1 m y)

247+ -> (x -> pq schemas0 schemas1 m y)

242− -> x -> pq schema0 schema2 m z

248+ -> x -> pq schemas0 schemas2 m z

243 pqAndThen g f x = pqBind g (f x)

249 pqAndThen g f x = pqBind g (f x)

244

250

245− -- | Safely embed a computation in a larger schema.

246− pqEmbed

247− :: Monad m

248− => pq schema0 schema1 m x

249− -> pq (table ': schema0) (table : schema1) m x

250−

251− -- | 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.

252 --

254 --

255+ -- @define id = return ()@

253− -- @define statement1 & pqThen (define statement2) = define (statement1 >>> statement2)@

256+ -- @define (statement1 >>> statement2) = define statement1 & pqThen (define statement2)@

254 define

257 define

255− :: MonadBase IO io

258+ :: MonadIO io

256− => Definition schema0 schema1

259+ => Definition schemas0 schemas1

257− -> pq schema0 schema1 io (K LibPQ.Result '[])

260+ -> pq schemas0 schemas1 io ()

258

261

259instance IndexedMonadTransPQ PQ where

262instance IndexedMonadTransPQ PQ where

260

263

@@ -267,26 +270,26 @@ instance IndexedMonadTransPQ PQ where

267 K x' <- x conn

270 K x' <- x conn

268 unPQ (f x') (K (unK conn))

271 unPQ (f x') (K (unK conn))

269

272

270− pqEmbed (PQ pq) = PQ $ \ (K conn) -> do

271− K x <- pq (K conn)

272− return $ K x

273−

274 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

273 define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

275− resultMaybe <- liftBase $ LibPQ.exec conn q

274+ resultMaybe <- liftIO $ LibPQ.exec conn q

276 case resultMaybe of

275 case resultMaybe of

277− Nothing -> error

276+ Nothing -> throw $ ResultException

278 "define: LibPQ.exec returned no results"

277 "define: LibPQ.exec returned no results"

279− Just result -> return $ K (K result)

278+ Just result -> K <$> okResult_ result

280

279

281−{- | `MonadPQ` is an `mtl` style constraint, similar to

280+{- | `MonadPQ` is an @mtl@ style constraint, similar to

282−`Control.Monad.State.Class.MonadState`, for using `LibPQ` to

281+`Control.Monad.State.Class.MonadState`, for using `Database.PostgreSQL.LibPQ` to

283

282

284* `manipulateParams` runs a `Manipulation` with params from a type

283* `manipulateParams` runs a `Manipulation` with params from a type

285 with a `ToParams` constraint. It calls `LibPQ.execParams` and

284 with a `ToParams` constraint. It calls `LibPQ.execParams` and

286 doesn't afraid of anything.

285 doesn't afraid of anything.

287

286

287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.

288+

288* `manipulate` is like `manipulateParams` for a parameter-free statement.

289* `manipulate` is like `manipulateParams` for a parameter-free statement.

289

290

291+* `manipulate_` is like `manipulate` for a returning-free statement.

292+

290* `runQueryParams` is like `manipulateParams` for query statements.

293* `runQueryParams` is like `manipulateParams` for query statements.

291

294

292* `runQuery` is like `runQueryParams` for a parameter-free statement.

295* `runQuery` is like `runQueryParams` for a parameter-free statement.

@@ -300,11 +303,11 @@ instance IndexedMonadTransPQ PQ where

300* `forPrepared` is a flipped `traversePrepared`

303* `forPrepared` is a flipped `traversePrepared`

301

304

302* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

305* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

303− containers and returns unit.

306+ containers for a returning-free statement.

304

307

305* `forPrepared_` is a flipped `traversePrepared_`.

308* `forPrepared_` is a flipped `traversePrepared_`.

306

309

307−* `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

308 into your monad.

311 into your monad.

309

312

310To define an instance, you can minimally define only `manipulateParams`,

313To define an instance, you can minimally define only `manipulateParams`,

@@ -312,304 +315,398 @@ To define an instance, you can minimally define only `manipulateParams`,

312a default instance.

315a default instance.

313

316

314-}

317-}

315−class Monad pq => MonadPQ schema pq | pq -> schema where

318+class Monad pq => MonadPQ schemas pq | pq -> schemas where

316 manipulateParams

319 manipulateParams

317− :: ToParams x params

320+ :: (ToParams x params, All OidOfParam params)

318− => Manipulation schema params ys

321+ => Manipulation '[] schemas params ys

319− -- ^ `insertRows`, `update` or `deleteFrom`

322+ -- ^ `insertInto`, `update` or `deleteFrom`

320 -> x -> pq (K LibPQ.Result ys)

323 -> x -> pq (K LibPQ.Result ys)

321 default manipulateParams

324 default manipulateParams

322− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

325+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

323− => ToParams x params

326+ => (ToParams x params, All OidOfParam params)

324− => Manipulation schema params ys

327+ => Manipulation '[] schemas params ys

325− -- ^ `insertRows`, `update` or `deleteFrom`

328+ -- ^ `insertInto`, `update` or `deleteFrom`

326 -> x -> pq (K LibPQ.Result ys)

329 -> x -> pq (K LibPQ.Result ys)

327 manipulateParams manipulation params = lift $

330 manipulateParams manipulation params = lift $

328 manipulateParams manipulation params

331 manipulateParams manipulation params

329

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+

330− manipulate :: Manipulation schema '[] ys -> pq (K LibPQ.Result ys)

340+ manipulate :: Manipulation '[] schemas '[] ys -> pq (K LibPQ.Result ys)

331 manipulate statement = manipulateParams statement ()

341 manipulate statement = manipulateParams statement ()

332

342

343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()

344+ manipulate_ = void . manipulate

345+

333 runQueryParams

346 runQueryParams

334− :: ToParams x params

347+ :: (ToParams x params, All OidOfParam params)

335− => Query schema params ys

348+ => Query '[] '[] schemas params ys

336 -- ^ `select` and friends

349 -- ^ `select` and friends

337 -> x -> pq (K LibPQ.Result ys)

350 -> x -> pq (K LibPQ.Result ys)

338 runQueryParams = manipulateParams . queryStatement

351 runQueryParams = manipulateParams . queryStatement

339

352

340 runQuery

353 runQuery

341− :: Query schema '[] ys

354+ :: Query '[] '[] schemas '[] ys

342 -- ^ `select` and friends

355 -- ^ `select` and friends

343 -> pq (K LibPQ.Result ys)

356 -> pq (K LibPQ.Result ys)

344 runQuery q = runQueryParams q ()

357 runQuery q = runQueryParams q ()

345

358

346 traversePrepared

359 traversePrepared

347− :: (ToParams x params, Traversable list)

360+ :: (ToParams x params, Traversable list, All OidOfParam params)

348− => Manipulation schema params ys

361+ => Manipulation '[] schemas params ys

349− -- ^ `insertRows`, `update`, or `deleteFrom`, and friends

362+ -- ^ `insertInto`, `update`, or `deleteFrom`, and friends

350 -> list x -> pq (list (K LibPQ.Result ys))

363 -> list x -> pq (list (K LibPQ.Result ys))

351 default traversePrepared

364 default traversePrepared

352− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

365+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

353− => (ToParams x params, Traversable list)

366+ => (ToParams x params, Traversable list, All OidOfParam params)

354− => 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))

355 traversePrepared manipulation params = lift $

368 traversePrepared manipulation params = lift $

356 traversePrepared manipulation params

369 traversePrepared manipulation params

357

370

358 forPrepared

371 forPrepared

359− :: (ToParams x params, Traversable list)

372+ :: (ToParams x params, Traversable list, All OidOfParam params)

360 => list x

373 => list x

361− -> Manipulation schema params ys

374+ -> Manipulation '[] schemas params ys

362− -- ^ `insertRows`, `update` or `deleteFrom`

375+ -- ^ `insertInto`, `update` or `deleteFrom`

363 -> pq (list (K LibPQ.Result ys))

376 -> pq (list (K LibPQ.Result ys))

364 forPrepared = flip traversePrepared

377 forPrepared = flip traversePrepared

365

378

366 traversePrepared_

379 traversePrepared_

367− :: (ToParams x params, Foldable list)

380+ :: (ToParams x params, Foldable list, All OidOfParam params)

368− => Manipulation schema params '[]

381+ => Manipulation '[] schemas params '[]

369− -- ^ `insertRows`, `update` or `deleteFrom`

382+ -- ^ `insertInto`, `update` or `deleteFrom`

370 -> list x -> pq ()

383 -> list x -> pq ()

371 default traversePrepared_

384 default traversePrepared_

372− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

385+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

373− => (ToParams x params, Foldable list)

386+ => (ToParams x params, Foldable list, All OidOfParam params)

374− => Manipulation schema params '[]

387+ => Manipulation '[] schemas params '[]

375− -- ^ `insertRows`, `update` or `deleteFrom`

388+ -- ^ `insertInto`, `update` or `deleteFrom`

376 -> list x -> pq ()

389 -> list x -> pq ()

377 traversePrepared_ manipulation params = lift $

390 traversePrepared_ manipulation params = lift $

378 traversePrepared_ manipulation params

391 traversePrepared_ manipulation params

379

392

380 forPrepared_

393 forPrepared_

381− :: (ToParams x params, Foldable list)

394+ :: (ToParams x params, Foldable list, All OidOfParam params)

382 => list x

395 => list x

383− -> Manipulation schema params '[]

396+ -> Manipulation '[] schemas params '[]

384− -- ^ `insertRows`, `update` or `deleteFrom`

397+ -- ^ `insertInto`, `update` or `deleteFrom`

385 -> pq ()

398 -> pq ()

386 forPrepared_ = flip traversePrepared_

399 forPrepared_ = flip traversePrepared_

387

400

388 liftPQ :: (LibPQ.Connection -> IO a) -> pq a

401 liftPQ :: (LibPQ.Connection -> IO a) -> pq a

389 default liftPQ

402 default liftPQ

390− :: (MonadTrans t, MonadPQ schema pq1, pq ~ t pq1)

403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

391 => (LibPQ.Connection -> IO a) -> pq a

404 => (LibPQ.Connection -> IO a) -> pq a

392 liftPQ = lift . liftPQ

405 liftPQ = lift . liftPQ

393

406

394−instance (MonadBase IO io, schema0 ~ schema, schema1 ~ schema)

407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)

395− => MonadPQ schema (PQ schema0 schema1 io) where

408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where

396

409

397 manipulateParams

410 manipulateParams

398− (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =

411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =

399 PQ $ \ (K conn) -> do

412 PQ $ \ (K conn) -> do

400 let

413 let

401− 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

402− params' = fmap (fmap toParam') (hcollapse (toParams @x @ps params))

424+ $ toParams @x @ps params

425+ q' = q <> ";"

403− resultMaybe <- liftBase $ LibPQ.execParams conn q params' LibPQ.Binary

426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary

404 case resultMaybe of

427 case resultMaybe of

405− Nothing -> error

428+ Nothing -> throw $ ResultException

406 "manipulateParams: LibPQ.execParams returned no results"

429 "manipulateParams: LibPQ.execParams returned no results"

430+ Just result -> do

431+ okResult_ result

407− Just result -> return $ K (K result)

432+ return $ K (K result)

408

433

409 traversePrepared

434 traversePrepared

410− (UnsafeManipulation q :: Manipulation schema xs ys) (list :: list x) =

435+ (UnsafeManipulation q :: Manipulation '[] schemas xs ys) (list :: list x) =

411− PQ $ \ (K conn) -> liftBase $ do

436+ PQ $ \ (K conn) -> liftIO $ do

437+ let

412− 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

413− prepResultMaybe <- LibPQ.prepare conn temp q Nothing

445+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

414 case prepResultMaybe of

446 case prepResultMaybe of

415− Nothing -> error

447+ Nothing -> throw $ ResultException

416 "traversePrepared: LibPQ.prepare returned no results"

448 "traversePrepared: LibPQ.prepare returned no results"

417− Just prepResult -> do

449+ Just prepResult -> okResult_ prepResult

418− status <- LibPQ.resultStatus prepResult

419− unless (status == LibPQ.CommandOk) . error $

420− "traversePrepared: LibPQ.prepare status " <> show status

421 results <- for list $ \ params -> do

450 results <- for list $ \ params -> do

422 let

451 let

423− toParam' bytes = (bytes,LibPQ.Binary)

452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

424 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

453 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

425 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

454 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

426 case resultMaybe of

455 case resultMaybe of

427− Nothing -> error

456+ Nothing -> throw $ ResultException

428 "traversePrepared: LibPQ.execParams returned no results"

457 "traversePrepared: LibPQ.execParams returned no results"

458+ Just result -> do

459+ okResult_ result

429− Just result -> return $ K result

460+ return $ K result

430 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

431 case deallocResultMaybe of

462 case deallocResultMaybe of

432− Nothing -> error

463+ Nothing -> throw $ ResultException

433 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

434− Just deallocResult -> do

465+ Just deallocResult -> okResult_ deallocResult

435− status <- LibPQ.resultStatus deallocResult

436− unless (status == LibPQ.CommandOk) . error $

437− "traversePrepared: DEALLOCATE status " <> show status

438 return (K results)

466 return (K results)

439

467

440 traversePrepared_

468 traversePrepared_

441− (UnsafeManipulation q :: Manipulation schema xs '[]) (list :: list x) =

469+ (UnsafeManipulation q :: Manipulation '[] schemas xs '[]) (list :: list x) =

442− PQ $ \ (K conn) -> liftBase $ do

470+ PQ $ \ (K conn) -> liftIO $ do

471+ let

443− 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

444− prepResultMaybe <- LibPQ.prepare conn temp q Nothing

479+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

445 case prepResultMaybe of

480 case prepResultMaybe of

446− Nothing -> error

481+ Nothing -> throw $ ResultException

447 "traversePrepared_: LibPQ.prepare returned no results"

482 "traversePrepared_: LibPQ.prepare returned no results"

448− Just prepResult -> do

483+ Just prepResult -> okResult_ prepResult

449− status <- LibPQ.resultStatus prepResult

450− unless (status == LibPQ.CommandOk) . error $

451− "traversePrepared: LibPQ.prepare status " <> show status

452 for_ list $ \ params -> do

484 for_ list $ \ params -> do

453 let

485 let

454− toParam' bytes = (bytes,LibPQ.Binary)

486+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

455 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

487 params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

456 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

488 resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

457 case resultMaybe of

489 case resultMaybe of

458− Nothing -> error

490+ Nothing -> throw $ ResultException

459 "traversePrepared_: LibPQ.execParams returned no results"

491 "traversePrepared_: LibPQ.execParams returned no results"

460− Just _result -> return ()

492+ Just result -> okResult_ result

461 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

493 deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

462 case deallocResultMaybe of

494 case deallocResultMaybe of

463− Nothing -> error

495+ Nothing -> throw $ ResultException

464 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

496 "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

465− Just deallocResult -> do

497+ Just deallocResult -> okResult_ deallocResult

466− status <- LibPQ.resultStatus deallocResult

467− unless (status == LibPQ.CommandOk) . error $

468− "traversePrepared: DEALLOCATE status " <> show status

469 return (K ())

498 return (K ())

470

499

471 liftPQ pq = PQ $ \ (K conn) -> do

500 liftPQ pq = PQ $ \ (K conn) -> do

472− y <- liftBase $ pq conn

501+ y <- liftIO $ pq conn

473 return (K y)

502 return (K y)

474

503

475−instance MonadPQ schema m => MonadPQ schema (IdentityT m)

504+instance MonadPQ schemas m => MonadPQ schemas (IdentityT m)

476−instance MonadPQ schema m => MonadPQ schema (ReaderT r m)

505+instance MonadPQ schemas m => MonadPQ schemas (ReaderT r m)

477−instance MonadPQ schema m => MonadPQ schema (Strict.StateT s m)

506+instance MonadPQ schemas m => MonadPQ schemas (Strict.StateT s m)

478−instance MonadPQ schema m => MonadPQ schema (Lazy.StateT s m)

507+instance MonadPQ schemas m => MonadPQ schemas (Lazy.StateT s m)

479−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)

480−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)

481−instance MonadPQ schema m => MonadPQ schema (MaybeT m)

510+instance MonadPQ schemas m => MonadPQ schemas (MaybeT m)

482−instance MonadPQ schema m => MonadPQ schema (ExceptT e m)

511+instance MonadPQ schemas m => MonadPQ schemas (ExceptT e m)

483−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)

484−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)

485−instance MonadPQ schema m => MonadPQ schema (ContT r m)

514+instance MonadPQ schemas m => MonadPQ schemas (ContT r m)

486−instance MonadPQ schema m => MonadPQ schema (ListT m)

515+

487−

488−instance (Monad m, schema0 ~ schema1)

516+instance (Monad m, schemas0 ~ schemas1)

489− => Applicative (PQ schema0 schema1 m) where

517+ => Applicative (PQ schemas0 schemas1 m) where

490 pure x = PQ $ \ _conn -> pure (K x)

518 pure x = PQ $ \ _conn -> pure (K x)

491 (<*>) = pqAp

519 (<*>) = pqAp

492

520

493−instance (Monad m, schema0 ~ schema1)

521+instance (Monad m, schemas0 ~ schemas1)

494− => Monad (PQ schema0 schema1 m) where

522+ => Monad (PQ schemas0 schemas1 m) where

495 return = pure

523 return = pure

496 (>>=) = flip pqBind

524 (>>=) = flip pqBind

497

525

498−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

499 hoist f (PQ pq) = PQ (f . pq)

531 hoist f (PQ pq) = PQ (f . pq)

500

532

501−instance schema0 ~ schema1 => MonadTrans (PQ schema0 schema1) where

533+instance schemas0 ~ schemas1 => MonadTrans (PQ schemas0 schemas1) where

502 lift m = PQ $ \ _conn -> do

534 lift m = PQ $ \ _conn -> do

503 x <- m

535 x <- m

504 return (K x)

536 return (K x)

505

537

506−instance schema0 ~ schema1 => MMonad (PQ schema0 schema1) where

538+instance schemas0 ~ schemas1 => MMonad (PQ schemas0 schemas1) where

507 embed f (PQ pq) = PQ $ \ conn -> do

539 embed f (PQ pq) = PQ $ \ conn -> do

508 evalPQ (f (pq conn)) conn

540 evalPQ (f (pq conn)) conn

509

541

510−instance (MonadBase b m, schema0 ~ schema1)

542+instance (MonadIO m, schema0 ~ schema1)

511− => MonadBase b (PQ schema0 schema1 m) where

543+ => MonadIO (PQ schema0 schema1 m) where

512− liftBase = lift . liftBase

544+ liftIO = lift . liftIO

513

545

514−-- | A snapshot of the state of a `PQ` computation.

546+instance (MonadUnliftIO m, schemas0 ~ schemas1)

515−type PQRun schema =

547+ => MonadUnliftIO (PQ schemas0 schemas1 m) where

516− forall m x. Monad m => PQ schema schema m x -> m (K x schema)

548+ withRunInIO

517−

549+ :: ((forall a . PQ schemas0 schema1 m a -> IO a) -> IO b)

518−-- | Helper function in defining `MonadBaseControl` instance for `PQ`.

550+ -> PQ schemas0 schema1 m b

519−pqliftWith :: Functor m => (PQRun schema -> m a) -> PQ schema schema m a

551+ withRunInIO inner = PQ $ \conn ->

520−pqliftWith f = PQ $ \ conn ->

552+ withRunInIO $ \(run :: (forall x . m x -> IO x)) ->

521− fmap K (f $ \ pq -> unPQ pq conn)

553+ K <$> inner (\pq -> run $ unK <$> unPQ pq conn)

522−

523−instance (MonadBaseControl b m, schema0 ~ schema1)

524− => MonadBaseControl b (PQ schema0 schema1 m) where

525− type StM (PQ schema0 schema1 m) x = StM m (K x schema0)

526− liftBaseWith f =

527− pqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

528− restoreM = PQ . const . restoreM

529

554

530-- | 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`,

531-- throwing an exception if the row number is out of bounds.

556-- throwing an exception if the row number is out of bounds.

532getRow

557getRow

533− :: (FromRow columns y, MonadBase IO io)

558+ :: (FromRow columns y, MonadIO io)

534 => LibPQ.Row

559 => LibPQ.Row

535 -- ^ row number

560 -- ^ row number

536 -> K LibPQ.Result columns

561 -> K LibPQ.Result columns

537 -- ^ result

562 -- ^ result

538 -> io y

563 -> io y

539−getRow r (K result :: K LibPQ.Result columns) = liftBase $ do

564+getRow r (K result :: K LibPQ.Result columns) = liftIO $ do

540 numRows <- LibPQ.ntuples result

565 numRows <- LibPQ.ntuples result

541− when (numRows < r) $ error $

566+ when (numRows < r) $ throw $ ResultException $

542− "getRow: expected at least " <> show r <> "rows but only saw "

567+ "getRow: expected at least " <> pack (show r) <> "rows but only saw "

543− <> show numRows

568+ <> pack (show numRows)

544 let len = fromIntegral (lengthSList (Proxy @columns))

569 let len = fromIntegral (lengthSList (Proxy @columns))

545 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

570 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

546 case fromList row' of

571 case fromList row' of

547− Nothing -> error "getRow: found unexpected length"

572+ Nothing -> throw $ ResultException "getRow: found unexpected length"

548− 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

549

576

550-- | Intended to be used for unfolding in streaming libraries, `nextRow`

577-- | Intended to be used for unfolding in streaming libraries, `nextRow`

551-- 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`)

552-- 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`,

553-- otherwise returning the row along with the next row number.

580-- otherwise returning the row along with the next row number.

554nextRow

581nextRow

555− :: (FromRow columns y, MonadBase IO io)

582+ :: (FromRow columns y, MonadIO io)

556 => LibPQ.Row -- ^ total number of rows

583 => LibPQ.Row -- ^ total number of rows

557 -> K LibPQ.Result columns -- ^ result

584 -> K LibPQ.Result columns -- ^ result

558 -> LibPQ.Row -- ^ row number

585 -> LibPQ.Row -- ^ row number

559 -> io (Maybe (LibPQ.Row,y))

586 -> io (Maybe (LibPQ.Row,y))

560nextRow total (K result :: K LibPQ.Result columns) r

587nextRow total (K result :: K LibPQ.Result columns) r

561− = liftBase $ if r >= total then return Nothing else do

588+ = liftIO $ if r >= total then return Nothing else do

562 let len = fromIntegral (lengthSList (Proxy @columns))

589 let len = fromIntegral (lengthSList (Proxy @columns))

563 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

590 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

564 case fromList row' of

591 case fromList row' of

565− 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

566− Just row -> return $ Just (r+1, fromRow @columns row)

595+ Right y -> return $ Just (r+1, y)

567

596

568-- | Get all rows from a `LibPQ.Result`.

597-- | Get all rows from a `LibPQ.Result`.

569getRows

598getRows

570− :: (FromRow columns y, MonadBase IO io)

599+ :: (FromRow columns y, MonadIO io)

571 => K LibPQ.Result columns -- ^ result

600 => K LibPQ.Result columns -- ^ result

572 -> io [y]

601 -> io [y]

573−getRows (K result :: K LibPQ.Result columns) = liftBase $ do

602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do

574 let len = fromIntegral (lengthSList (Proxy @columns))

603 let len = fromIntegral (lengthSList (Proxy @columns))

575 numRows <- LibPQ.ntuples result

604 numRows <- LibPQ.ntuples result

576 for [0 .. numRows - 1] $ \ r -> do

605 for [0 .. numRows - 1] $ \ r -> do

577 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

606 row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

578 case fromList row' of

607 case fromList row' of

579− Nothing -> error "getRows: found unexpected length"

608+ Nothing -> throw $ ResultException "getRows: found unexpected length"

580− 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

581

612

582-- | Get the first row if possible from a `LibPQ.Result`.

613-- | Get the first row if possible from a `LibPQ.Result`.

583firstRow

614firstRow

584− :: (FromRow columns y, MonadBase IO io)

615+ :: (FromRow columns y, MonadIO io)

585 => K LibPQ.Result columns -- ^ result

616 => K LibPQ.Result columns -- ^ result

586 -> io (Maybe y)

617 -> io (Maybe y)

587−firstRow (K result :: K LibPQ.Result columns) = liftBase $ do

618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do

588 numRows <- LibPQ.ntuples result

619 numRows <- LibPQ.ntuples result

589 if numRows <= 0 then return Nothing else do

620 if numRows <= 0 then return Nothing else do

590 let len = fromIntegral (lengthSList (Proxy @columns))

621 let len = fromIntegral (lengthSList (Proxy @columns))

591 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]

622 row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]

592 case fromList row' of

623 case fromList row' of

593− Nothing -> error "firstRow: found unexpected length"

624+ Nothing -> throw $ ResultException "firstRow: found unexpected length"

594− 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

595

628

596-- | Lifts actions on results from @LibPQ@.

629-- | Lifts actions on results from @LibPQ@.

597liftResult

630liftResult

598− :: MonadBase IO io

631+ :: MonadIO io

599 => (LibPQ.Result -> IO x)

632 => (LibPQ.Result -> IO x)

600 -> K LibPQ.Result results -> io x

633 -> K LibPQ.Result results -> io x

601−liftResult f (K result) = liftBase $ f result

634+liftResult f (K result) = liftIO $ f result

602

635

603-- | Returns the number of rows (tuples) in the query result.

636-- | Returns the number of rows (tuples) in the query result.

604−ntuples :: MonadBase IO io => K LibPQ.Result columns -> io LibPQ.Row

637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row

605ntuples = liftResult LibPQ.ntuples

638ntuples = liftResult LibPQ.ntuples

606

639

607-- | Returns the result status of the command.

640-- | Returns the result status of the command.

608−resultStatus :: MonadBase IO io => K LibPQ.Result results -> io LibPQ.ExecStatus

641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus

609resultStatus = liftResult LibPQ.resultStatus

642resultStatus = liftResult LibPQ.resultStatus

610

643

611-- | Returns the error message most recently generated by an operation

644-- | Returns the error message most recently generated by an operation

612-- on the connection.

645-- on the connection.

613resultErrorMessage

646resultErrorMessage

614− :: MonadBase IO io => K LibPQ.Result results -> io (Maybe ByteString)

647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)

615resultErrorMessage = liftResult LibPQ.resultErrorMessage

648resultErrorMessage = liftResult LibPQ.resultErrorMessage

649+

650+-- | Returns the error code most recently generated by an operation

651+-- on the connection.

652+--

653+-- https://www.postgresql.org/docs/current/static/errcodes-appendix.html

654+resultErrorCode

655+ :: MonadIO io

656+ => K LibPQ.Result results

657+ -> io (Maybe ByteString)

658+resultErrorCode = liftResult (flip LibPQ.resultErrorField LibPQ.DiagSqlstate)

659+

660+-- | the state of LibPQ

661+data PQState = PQState

662+ { sqlExecStatus :: LibPQ.ExecStatus

663+ , sqlStateCode :: Maybe ByteString

664+ -- ^ https://www.postgresql.org/docs/current/static/errcodes-appendix.html

665+ , sqlErrorMessage :: Maybe ByteString

666+ } deriving (Eq, Show)

667+

668+-- | `Exception`s that can be thrown by Squeal.

669+data SquealException

670+ = PQException PQState

671+ | ResultException Text

672+ | ParseException Text

673+ deriving (Eq, Show)

674+instance Exception SquealException

675+

676+okResult_ :: MonadIO io => LibPQ.Result -> io ()

677+okResult_ result = liftIO $ do

678+ status <- LibPQ.resultStatus result

679+ case status of

680+ LibPQ.CommandOk -> return ()

681+ LibPQ.TuplesOk -> return ()

682+ _ -> do

683+ stateCode <- LibPQ.resultErrorField result LibPQ.DiagSqlstate

684+ msg <- LibPQ.resultErrorMessage result

685+ throw . PQException $ PQState status stateCode msg

686+

687+-- | Check if a `LibPQ.Result`'s status is either `LibPQ.CommandOk`

688+-- or `LibPQ.TuplesOk` otherwise `throw` a `PQException`.

689+okResult :: MonadIO io => K LibPQ.Result row -> io ()

690+okResult = okResult_ . unK

691+

692+-- | Catch `SquealException`s.

693+catchSqueal

694+ :: MonadUnliftIO io

695+ => io a

696+ -> (SquealException -> io a) -- ^ handler

697+ -> io a

698+catchSqueal = catch

699+

700+-- | Handle `SquealException`s.

701+handleSqueal

702+ :: MonadUnliftIO io

703+ => (SquealException -> io a) -- ^ handler

704+ -> io a -> io a

705+handleSqueal = handle

706+

707+-- | `Either` return a `SquealException` or a result.

708+trySqueal

709+ :: MonadUnliftIO io

710+ => io a

711+ -> io (Either SquealException a)

712+trySqueal = try

squeal-postgresql/src/Squeal/PostgreSQL/Pool.hs+70−81

@@ -1,18 +1,40 @@

1{-|

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− DataKinds

13− , DeriveFunctor

34+ DeriveFunctor

14 , FlexibleContexts

35 , FlexibleContexts

15 , FlexibleInstances

36 , FlexibleInstances

37+ , InstanceSigs

16 , MultiParamTypeClasses

38 , MultiParamTypeClasses

17 , RankNTypes

39 , RankNTypes

18 , ScopedTypeVariables

40 , ScopedTypeVariables

@@ -23,34 +45,24 @@ A `MonadPQ` for pooled connections.

24module Squeal.PostgreSQL.Pool

46module Squeal.PostgreSQL.Pool

25 ( -- * Pools

47 ( -- * Pools

26− PoolPQ (..)

48+ Pool

27 , createConnectionPool

49 , createConnectionPool

28− , Pool

50+ , usingConnectionPool

29− , destroyAllResources

51+ , destroyConnectionPool

30− , PoolPQRun

31− , poolpqliftWith

32 ) where

52 ) where

34−import Control.Monad.Base

35−import Control.Monad.Trans

36−import Control.Monad.Trans.Control

37import Data.ByteString

54import Data.ByteString

38−import Data.Pool

39import Data.Time

55import Data.Time

40−import Generics.SOP (K(..))

56+import Generics.SOP (K(..), unK)

57+import UnliftIO (MonadUnliftIO (..))

58+import UnliftIO.Pool (Pool, createPool, destroyAllResources, withResource)

42import Squeal.PostgreSQL.PQ

60import Squeal.PostgreSQL.PQ

43−import Squeal.PostgreSQL.Schema

44−

45−-- | `PoolPQ` @schema@ should be a drop-in replacement for `PQ` @schema schema@.

46−newtype PoolPQ (schema :: SchemaType) m x =

47− PoolPQ { runPoolPQ :: Pool (K Connection schema) -> m x }

48− deriving Functor

50-- | Create a striped pool of connections.

62-- | Create a striped pool of connections.

51-- Although the garbage collector will destroy all idle connections when the pool is garbage collected it's recommended to manually `destroyAllResources` when you're done with the pool so that the connections are freed up as soon as possible.

63-- Although the garbage collector will destroy all idle connections when the pool is garbage collected it's recommended to manually `destroyAllResources` when you're done with the pool so that the connections are freed up as soon as possible.

52createConnectionPool

64createConnectionPool

53− :: MonadBase IO io

65+ :: MonadUnliftIO io

54 => ByteString

66 => ByteString

55 -- ^ The passed string can be empty to use all default parameters, or it can

67 -- ^ The passed string can be empty to use all default parameters, or it can

56 -- contain one or more parameter settings separated by whitespace.

68 -- contain one or more parameter settings separated by whitespace.

@@ -66,68 +78,45 @@ createConnectionPool

66 -> Int

78 -> Int

67 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

79 -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

68 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

80 -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

69− -> io (Pool (K Connection schema))

81+ -> io (Pool (K Connection schemas))

70−createConnectionPool conninfo stripes idle maxResrc = liftBase $

82+createConnectionPool conninfo stripes idle maxResrc =

71 createPool (connectdb conninfo) finish stripes idle maxResrc

83 createPool (connectdb conninfo) finish stripes idle maxResrc

73−-- | `Applicative` instance for `PoolPQ`.

85+{-|

74−instance Monad m => Applicative (PoolPQ schema m) where

86+Temporarily take a connection from a `Pool`, perform an action with it,

75− pure x = PoolPQ $ \ _ -> pure x

87+and return it to the pool afterwards.

76− PoolPQ f <*> PoolPQ x = PoolPQ $ \ pool -> do

77− f' <- f pool

78− x' <- x pool

79− return $ f' x'

80−

81−-- | `Monad` instance for `PoolPQ`.

82−instance Monad m => Monad (PoolPQ schema m) where

83− return = pure

84− PoolPQ x >>= f = PoolPQ $ \ pool -> do

85− x' <- x pool

86− runPoolPQ (f x') pool

87−

88−-- | `MonadTrans` instance for `PoolPQ`.

89−instance MonadTrans (PoolPQ schema) where

90− lift m = PoolPQ $ \ _pool -> m

91−

92−-- | `MonadBase` instance for `PoolPQ`.

93−instance MonadBase b m => MonadBase b (PoolPQ schema m) where

94− liftBase = lift . liftBase

96−-- | `MonadPQ` instance for `PoolPQ`.

89+If the pool has an idle connection available, it is used immediately.

97−instance MonadBaseControl IO io => MonadPQ schema (PoolPQ schema io) where

90+Otherwise, if the maximum number of connections has not yet been reached,

98− manipulateParams manipulation params = PoolPQ $ \ pool -> do

91+a new connection is created and used.

99− withResource pool $ \ conn -> do

92+If the maximum number of connections has been reached, this function blocks

100− (K result :: K (K Result ys) schema) <- flip unPQ conn $

93+until a connection becomes available.

101− manipulateParams manipulation params

94+-}

102− return result

95+usingConnectionPool

103− traversePrepared manipulation params = PoolPQ $ \ pool ->

96+ :: MonadUnliftIO io

104− withResource pool $ \ conn -> do

97+ => Pool (K Connection schemas) -- ^ pool

105− (K result :: K (list (K Result ys)) schema) <- flip unPQ conn $

98+ -> PQ schemas schemas io x -- ^ session

106− traversePrepared manipulation params

99+ -> io x

107− return result

108− traversePrepared_ manipulation params = PoolPQ $ \ pool -> do

109− withResource pool $ \ conn -> do

110− (_ :: K () schema) <- flip unPQ conn $

111− traversePrepared_ manipulation params

112− return ()

113− liftPQ m = PoolPQ $ \ pool ->

114− withResource pool $ \ conn -> do

100+usingConnectionPool pool (PQ session) = unK <$> withResource pool session

115− (K result :: K result schema) <- flip unPQ conn $

116− liftPQ m

117− return result

118

101

119−-- | A snapshot of the state of a `PoolPQ` computation.

102+{- |

120−type PoolPQRun schema =

103+Destroy all connections in all stripes in the pool.

121− forall m x. Monad m => PoolPQ schema m x -> m x

104+Note that this will ignore any exceptions in the destroy function.

122

105

123−-- | Helper function in defining `MonadBaseControl` instance for `PoolPQ`.

106+This function is useful when you detect that all connections

124−poolpqliftWith :: Functor m => (PoolPQRun schema -> m a) -> PoolPQ schema m a

107+in the pool are broken. For example after a database has been

125−poolpqliftWith f = PoolPQ $ \ pool ->

108+restarted all connections opened before the restart will be broken.

126− (f $ \ pq -> runPoolPQ pq pool)

109+In that case it's better to close those connections so that

110+`usingConnectionPool` won't take a broken connection from the pool

111+but will open a new connection instead.

127

112

128−-- | `MonadBaseControl` instance for `PoolPQ`.

113+Another use-case for this function is that when you know you are done

129−instance MonadBaseControl b m => MonadBaseControl b (PoolPQ schema m) where

114+with the pool you can destroy all idle connections immediately

130− type StM (PoolPQ schema m) x = StM m x

115+instead of waiting on the garbage collector to destroy them,

131− liftBaseWith f =

116+thus freeing up those connections sooner.

132− poolpqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

117+-}

133− restoreM = PoolPQ . const . restoreM

118+destroyConnectionPool

119+ :: MonadUnliftIO io

120+ => Pool (K Connection schemas) -- ^ pool

121+ -> io ()

122+destroyConnectionPool = destroyAllResources

squeal-postgresql/src/Squeal/PostgreSQL/Query.hs+722−445

@@ -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− DataKinds

12+ ConstraintKinds

13− , DeriveDataTypeable

14 , DeriveGeneric

13 , DeriveGeneric

15 , FlexibleContexts

14 , FlexibleContexts

16 , FlexibleInstances

15 , FlexibleInstances

17 , GADTs

16 , GADTs

18 , GeneralizedNewtypeDeriving

17 , GeneralizedNewtypeDeriving

19− , KindSignatures

20 , LambdaCase

18 , LambdaCase

21 , MultiParamTypeClasses

19 , MultiParamTypeClasses

20+ , OverloadedLabels

22 , OverloadedStrings

21 , OverloadedStrings

22+ , QuantifiedConstraints

23 , ScopedTypeVariables

24 , StandaloneDeriving

25 , TypeApplications

26+ , TypeFamilies

26 , TypeInType

27 , TypeInType

27 , TypeOperators

28 , TypeOperators

29+ , RankNTypes

28 , UndecidableInstances

30 , UndecidableInstances

29−#-}

31+ #-}

31module Squeal.PostgreSQL.Query

33module Squeal.PostgreSQL.Query

32 ( -- * Queries

34 ( -- * Queries

33− Query (UnsafeQuery, renderQuery)

35+ Query_

36+ , Query (..)

37+ -- ** Select

38+ , select

39+ , select_

40+ , selectDistinct

41+ , selectDistinct_

42+ , selectDistinctOn

43+ , selectDistinctOn_

44+ , Selection (..)

45+ -- ** Values

46+ , values

47+ , values_

48+ -- ** Set Operations

34 , union

49 , union

35 , unionAll

50 , unionAll

36 , intersect

51 , intersect

37 , intersectAll

52 , intersectAll

38 , except

53 , except

39 , exceptAll

54 , exceptAll

40− -- * Select

55+ -- ** With

41− , select

56+ , With (..)

42− , selectDistinct

57+ , CommonTableExpression (..)

43− , selectStar

58+ , withRecursive

44− , selectDistinctStar

45− , selectDotStar

46− , selectDistinctDotStar

47 -- * Table Expressions

59 -- * Table Expressions

48 , TableExpression (..)

60 , TableExpression (..)

49− , renderTableExpression

50 , from

61 , from

51 , where_

62 , where_

52− , group

63+ , groupBy

53 , having

64 , having

54− , orderBy

55 , limit

65 , limit

56 , offset

66 , offset

57− -- * From

67+ -- * From Clauses

58 , FromClause (..)

68 , FromClause (..)

59 , table

69 , table

60 , subquery

70 , subquery

61 , view

71 , view

72+ , common

62 , crossJoin

73 , crossJoin

63 , innerJoin

74 , innerJoin

64 , leftOuterJoin

75 , leftOuterJoin

65 , rightOuterJoin

76 , rightOuterJoin

66 , fullOuterJoin

77 , fullOuterJoin

67 -- * Grouping

78 -- * Grouping

68− , By (By, By2)

79+ , By (..)

69− , renderBy

70− , GroupByClause (NoGroups, Group)

80+ , GroupByClause (..)

71− , renderGroupByClause

72− , HavingClause (NoHaving, Having)

81+ , HavingClause (..)

73− , renderHavingClause

74− -- * Sorting

75− , SortExpression (..)

76− , renderSortExpression

77 ) where

82 ) where

79import Control.DeepSeq

84import Control.DeepSeq

80import Data.ByteString (ByteString)

85import Data.ByteString (ByteString)

81−import Data.Monoid hiding (All)

86+import Data.Kind (Type)

82import Data.String

87import Data.String

83import Data.Word

88import Data.Word

84import Generics.SOP hiding (from)

89import Generics.SOP hiding (from)

@@ -86,352 +91,577 @@ import GHC.TypeLits

87import qualified GHC.Generics as GHC

92import qualified GHC.Generics as GHC

94+import Squeal.PostgreSQL.Alias

89import 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

90import Squeal.PostgreSQL.Render

101import Squeal.PostgreSQL.Render

91import 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+

93{- |

111{- |

94−The process of retrieving or the command to retrieve data from a database

112+The process of retrieving or the command to retrieve data from

95−is called a `Query`. The `select`, `selectStar`, `selectDotStar`,

113+a database is called a `Query`.

96−`selectDistinct`, `selectDistinctStar` and `selectDistinctDotStar` commands

114+

97−are used to specify queries.

115+The general `Query` type is parameterized by

116+

117+* @outer :: FromType@ - outer scope for a correlated subquery,

118+* @commons :: FromType@ - scope for all `common` table expressions,

119+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

120+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

121+* @row :: RowType@ - return type of the `Query`.

122+-}

123+newtype Query

124+ (outer :: FromType)

125+ (commons :: FromType)

126+ (schemas :: SchemasType)

127+ (params :: [NullityType])

128+ (row :: RowType)

129+ = UnsafeQuery { renderQuery :: ByteString }

130+ deriving (GHC.Generic,Show,Eq,Ord,NFData)

131+instance RenderSQL (Query outer commons schemas params row) where renderSQL = renderQuery

132+

133+{- |

134+The top level `Query_` type is parameterized by a @schemas@ `SchemasType`,

135+against which the query is type-checked, an input @parameters@ Haskell `Type`,

136+and an ouput row Haskell `Type`.

137+

138+A top-level query can be run

139+using `Squeal.PostgreSQL.PQ.runQueryParams`, or if @parameters = ()@

140+using `Squeal.PostgreSQL.PQ.runQuery`.

141+

142+Generally, @parameters@ will be a Haskell tuple or record whose entries

143+may be referenced using positional

144+`Squeal.PostgreSQL.Expression.Parameter.parameter`s and @row@ will be a

145+Haskell record, whose entries will be targeted using overloaded labels.

146+

147+Let's see some examples of queries.

148+

149+>>> :set -XDeriveAnyClass -XDerivingStrategies

150+>>> :{

151+data Row a b = Row { col1 :: a, col2 :: b }

152+ deriving stock (GHC.Generic)

153+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

154+:}

155

99simple query:

156simple query:

100

157

158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

101>>> :{

160>>> :{

102let

161let

103− query :: Query

162+ query :: Query_ (Public Schema) () (Row Int32 Int32)

104− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

105− '[]

106− '["col" ::: 'Null 'PGint4]

107− query = selectStar (from (table (#tab `As` #t)))

163+ query = select Star (from (table #tab))

108−in renderQuery query

164+in printSQL query

109:}

165:}

110−"SELECT * FROM \"tab\" AS \"t\""

166+SELECT * FROM "tab" AS "tab"

111

167

112restricted query:

168restricted query:

113

169

114>>> :{

170>>> :{

115let

171let

116− query :: Query

172+ query :: Query_ (Public Schema) () (Row Int32 Int32)

117− '[ "tab" ::: 'Table ('[] :=>

118− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

119− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

120− '[]

121− '[ "sum" ::: 'NotNull 'PGint4

122− , "col1" ::: 'NotNull 'PGint4 ]

123− query =

173+ query =

124− select

125− ((#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)

174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)

126− ( from (table (#tab `As` #t))

175+ ( from (table #tab)

127 & where_ (#col1 .> #col2)

176 & where_ (#col1 .> #col2)

128 & where_ (#col2 .> 0) )

177 & where_ (#col2 .> 0) )

129−in renderQuery query

178+in printSQL query

130:}

179:}

131−"SELECT (\"col1\" + \"col2\") AS \"sum\", \"col1\" AS \"col1\" FROM \"tab\" AS \"t\" WHERE ((\"col1\" > \"col2\") AND (\"col2\" > 0))"

180+SELECT ("col1" + "col2") AS "col1", "col1" AS "col2" FROM "tab" AS "tab" WHERE (("col1" > "col2") AND ("col2" > 0))

132

181

133subquery:

182subquery:

134

183

135>>> :{

184>>> :{

136let

185let

137− query :: Query

186+ query :: Query_ (Public Schema) () (Row Int32 Int32)

138− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

139− '[]

140− '["col" ::: 'Null 'PGint4]

141− query =

142− selectStar

143− (from (subquery (selectStar (from (table (#tab `As` #t))) `As` #sub)))

187+ query = select Star (from (subquery (select Star (from (table #tab)) `as` #sub)))

144−in renderQuery query

188+in printSQL query

145:}

189:}

146−"SELECT * FROM (SELECT * FROM \"tab\" AS \"t\") AS \"sub\""

190+SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"

147

191

148limits and offsets:

192limits and offsets:

149

193

150>>> :{

194>>> :{

151let

195let

152− query :: Query

196+ query :: Query_ (Public Schema) () (Row Int32 Int32)

153− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

154− '[]

155− '["col" ::: 'Null 'PGint4]

156− query = selectStar

157− (from (table (#tab `As` #t)) & limit 100 & offset 2 & limit 50 & offset 2)

197+ query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)

158−in renderQuery query

198+in printSQL query

159:}

199:}

160−"SELECT * FROM \"tab\" AS \"t\" LIMIT 50 OFFSET 4"

200+SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4

161

201

162parameterized query:

202parameterized query:

163

203

164>>> :{

204>>> :{

165let

205let

166− query :: Query

206+ query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)

167− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8])]

168− '[ 'NotNull 'PGfloat8]

169− '["col" ::: 'NotNull 'PGfloat8]

170− query = selectStar

171− (from (table (#tab `As` #t)) & where_ (#col .> param @1))

207+ query = select Star (from (table #tab) & where_ (#col1 .> param @1))

172−in renderQuery query

208+in printSQL query

173:}

209:}

174−"SELECT * FROM \"tab\" AS \"t\" WHERE (\"col\" > ($1 :: float8))"

210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))

175

211

176aggregation query:

212aggregation query:

177

213

178>>> :{

214>>> :{

179let

215let

180− query :: Query

216+ query :: Query_ (Public Schema) () (Row Int64 Int32)

181− '[ "tab" ::: 'Table ('[] :=>

182− '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4

183− , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]

184− '[]

185− '[ "sum" ::: 'NotNull 'PGint4

186− , "col1" ::: 'NotNull 'PGint4 ]

187 query =

217 query =

188− select (sum_ #col2 `As` #sum :* #col1 `As` #col1 :* Nil)

218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)

189− ( from (table (#tab `As` #table1))

219+ ( from (table (#tab `as` #table1))

190− & group (By #col1 :* Nil)

220+ & groupBy #col1

191− & having (#col1 + sum_ #col2 .> 1) )

221+ & having (sum_ (Distinct #col2) .> 1) )

192−in renderQuery query

222+in printSQL query

193:}

223:}

194−"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)

195

225

196sorted query:

226sorted query:

197

227

198>>> :{

228>>> :{

199let

229let

200− query :: Query

230+ query :: Query_ (Public Schema) () (Row Int32 Int32)

201− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

202− '[]

203− '["col" ::: 'Null 'PGint4]

204− query = selectStar

205− (from (table (#tab `As` #t)) & orderBy [#col & AscNullsFirst])

231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])

206−in renderQuery query

232+in printSQL query

207:}

233:}

208−"SELECT * FROM \"tab\" AS \"t\" ORDER BY \"col\" ASC NULLS FIRST"

234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC

209

235

210joins:

236joins:

211

237

212−>>> :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+

213>>> :{

273>>> :{

214let

274let

215− query :: Query

275+ query :: Query_ (Public OrdersSchema) () Order

216− '[ "orders" ::: 'Table (

217− '["pk_orders" ::: PrimaryKey '["id"]

218− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]

219− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>

220− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

221− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4

222− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4

223− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4

224− ])

225− , "customers" ::: 'Table (

226− '["pk_customers" ::: PrimaryKey '["id"]] :=>

227− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

228− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

229− ])

230− , "shippers" ::: 'Table (

231− '["pk_shippers" ::: PrimaryKey '["id"]] :=>

232− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4

233− , "name" ::: 'NoDef :=> 'NotNull 'PGtext

234− ])

235− ]

236− '[]

237− '[ "order_price" ::: 'NotNull 'PGfloat4

238− , "customer_name" ::: 'NotNull 'PGtext

239− , "shipper_name" ::: 'NotNull 'PGtext

240− ]

241− query = select

276+ query = select_

242− ( #o ! #price `As` #order_price :*

277+ ( #o ! #price `as` #price :*

243− #c ! #name `As` #customer_name :*

278+ #c ! #name `as` #customerName :*

244− #s ! #name `As` #shipper_name :* Nil )

279+ #s ! #name `as` #shipperName )

245− ( from (table (#orders `As` #o)

280+ ( from (table (#orders `as` #o)

246− & innerJoin (table (#customers `As` #c))

281+ & innerJoin (table (#customers `as` #c))

247 (#o ! #customer_id .== #c ! #id)

282 (#o ! #customer_id .== #c ! #id)

248− & innerJoin (table (#shippers `As` #s))

283+ & innerJoin (table (#shippers `as` #s))

249 (#o ! #shipper_id .== #s ! #id)) )

284 (#o ! #shipper_id .== #s ! #id)) )

250−in renderQuery query

285+in printSQL query

251:}

286:}

252−"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")

253

288

254self-join:

289self-join:

255

290

256>>> :{

291>>> :{

257let

292let

258− query :: Query

293+ query :: Query_ (Public Schema) () (Row Int32 Int32)

259− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

294+ query = select

260− '[]

295+ (#t1 & DotStar)

261− '["col" ::: 'Null 'PGint4]

262− query = selectDotStar #t1

263− (from (table (#tab `As` #t1) & crossJoin (table (#tab `As` #t2))))

296+ (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))

264−in renderQuery query

297+in printSQL query

265:}

298:}

266−"SELECT \"t1\".* FROM \"tab\" AS \"t1\" CROSS JOIN \"tab\" AS \"t2\""

299+SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"

300+

301+value queries:

302+

303+>>> :{

304+let

305+ query :: Query_ schemas () (Row String Bool)

306+ query = values

307+ ("true" `as` #col1 :* true `as` #col2)

308+ ["false" `as` #col1 :* false `as` #col2]

309+in printSQL query

310+:}

311+SELECT * FROM (VALUES (E'true', TRUE), (E'false', FALSE)) AS t ("col1", "col2")

267

312

268set operations:

313set operations:

269

314

270>>> :{

315>>> :{

271let

316let

272− query :: Query

317+ query :: Query_ (Public Schema) () (Row Int32 Int32)

273− '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]

318+ query = select Star (from (table #tab)) `unionAll` select Star (from (table #tab))

274− '[]

319+in printSQL query

275− '["col" ::: 'Null 'PGint4]

320+:}

321+(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")

322+

323+with queries:

324+

325+>>> :{

326+let

327+ query :: Query_ (Public Schema) () (Row Int32 Int32)

328+ query = with (

329+ select Star (from (table #tab)) `as` #cte1 :>>

330+ select Star (from (common #cte1)) `as` #cte2

331+ ) (select Star (from (common #cte2)))

332+in printSQL query

333+:}

334+WITH "cte1" AS (SELECT * FROM "tab" AS "tab"), "cte2" AS (SELECT * FROM "cte1" AS "cte1") SELECT * FROM "cte2" AS "cte2"

335+

336+window function queries

337+

338+>>> :{

339+let

340+ query :: Query_ (Public Schema) () (Row Int32 Int64)

341+ query = select

342+ (#col1 & Also (rank `as` #col2 `Over` (partitionBy #col1 & orderBy [#col2 & Asc])))

343+ (from (table #tab))

344+in printSQL query

345+:}

346+SELECT "col1" AS "col1", rank() OVER (PARTITION BY "col1" ORDER BY "col2" ASC) AS "col2" FROM "tab" AS "tab"

347+

348+correlated subqueries

349+

350+>>> :{

351+let

352+ query :: Query_ (Public Schema) () (Only Int32)

276 query =

353 query =

277− selectStar (from (table (#tab `As` #t)))

354+ select (#col1 `as` #fromOnly) (from (table (#tab `as` #t1))

278− `unionAll`

355+ & where_ (exists (

279− selectStar (from (table (#tab `As` #t)))

356+ select Star (from (table (#tab `as` #t2))

357+ & where_ (#t2 ! #col2 .== #t1 ! #col1)))))

280−in renderQuery query

358+in printSQL query

281:}

359:}

282−"(SELECT * FROM \"tab\" AS \"t\") UNION ALL (SELECT * FROM \"tab\" AS \"t\")"

360+SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))

361+

283-}

362-}

284−newtype Query

363+type family Query_

285− (schema :: SchemaType)

364+ (schemas :: SchemasType)

286− (params :: [NullityType])

365+ (parameters :: Type)

287− (columns :: RelationType)

366+ (row :: Type) where

288− = UnsafeQuery { renderQuery :: ByteString }

367+ Query_ schemas params row =

289− deriving (GHC.Generic,Show,Eq,Ord,NFData)

368+ Query '[] '[] schemas (TuplePG params) (RowPG row)

290

369

291-- | 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

292−-- `union`. Duplicate rows are eliminated.

371+-- `union`. Duplicate rows are eliminated.

293union

372union

294− :: Query schema params columns

373+ :: Query outer commons schemas params columns

295− -> Query schema params columns

374+ -> Query outer commons schemas params columns

296− -> Query schema params columns

375+ -> Query outer commons schemas params columns

297q1 `union` q2 = UnsafeQuery $

376q1 `union` q2 = UnsafeQuery $

298− parenthesized (renderQuery q1)

377+ parenthesized (renderSQL q1)

299 <+> "UNION"

378 <+> "UNION"

300− <+> parenthesized (renderQuery q2)

379+ <+> parenthesized (renderSQL q2)

301

380

302-- | 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

303-- `unionAll`, the disjoint union. Duplicate rows are retained.

382-- `unionAll`, the disjoint union. Duplicate rows are retained.

304unionAll

383unionAll

305− :: Query schema params columns

384+ :: Query outer commons schemas params columns

306− -> Query schema params columns

385+ -> Query outer commons schemas params columns

307− -> Query schema params columns

386+ -> Query outer commons schemas params columns

308q1 `unionAll` q2 = UnsafeQuery $

387q1 `unionAll` q2 = UnsafeQuery $

309− parenthesized (renderQuery q1)

388+ parenthesized (renderSQL q1)

310 <+> "UNION" <+> "ALL"

389 <+> "UNION" <+> "ALL"

311− <+> parenthesized (renderQuery q2)

390+ <+> parenthesized (renderSQL q2)

312

391

313-- | 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

314-- `intersect`, the intersection. Duplicate rows are eliminated.

393-- `intersect`, the intersection. Duplicate rows are eliminated.

315intersect

394intersect

316− :: Query schema params columns

395+ :: Query outer commons schemas params columns

317− -> Query schema params columns

396+ -> Query outer commons schemas params columns

318− -> Query schema params columns

397+ -> Query outer commons schemas params columns

319q1 `intersect` q2 = UnsafeQuery $

398q1 `intersect` q2 = UnsafeQuery $

320− parenthesized (renderQuery q1)

399+ parenthesized (renderSQL q1)

321 <+> "INTERSECT"

400 <+> "INTERSECT"

322− <+> parenthesized (renderQuery q2)

401+ <+> parenthesized (renderSQL q2)

323

402

324-- | 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

325-- `intersectAll`, the intersection. Duplicate rows are retained.

404-- `intersectAll`, the intersection. Duplicate rows are retained.

326intersectAll

405intersectAll

327− :: Query schema params columns

406+ :: Query outer commons schemas params columns

328− -> Query schema params columns

407+ -> Query outer commons schemas params columns

329− -> Query schema params columns

408+ -> Query outer commons schemas params columns

330q1 `intersectAll` q2 = UnsafeQuery $

409q1 `intersectAll` q2 = UnsafeQuery $

331− parenthesized (renderQuery q1)

410+ parenthesized (renderSQL q1)

332 <+> "INTERSECT" <+> "ALL"

411 <+> "INTERSECT" <+> "ALL"

333− <+> parenthesized (renderQuery q2)

412+ <+> parenthesized (renderSQL q2)

334

413

335-- | 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

336-- `except`, the set difference. Duplicate rows are eliminated.

415-- `except`, the set difference. Duplicate rows are eliminated.

337except

416except

338− :: Query schema params columns

417+ :: Query outer commons schemas params columns

339− -> Query schema params columns

418+ -> Query outer commons schemas params columns

340− -> Query schema params columns

419+ -> Query outer commons schemas params columns

341q1 `except` q2 = UnsafeQuery $

420q1 `except` q2 = UnsafeQuery $

342− parenthesized (renderQuery q1)

421+ parenthesized (renderSQL q1)

343 <+> "EXCEPT"

422 <+> "EXCEPT"

344− <+> parenthesized (renderQuery q2)

423+ <+> parenthesized (renderSQL q2)

345

424

346-- | 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

347-- `exceptAll`, the set difference. Duplicate rows are retained.

426-- `exceptAll`, the set difference. Duplicate rows are retained.

348exceptAll

427exceptAll

349− :: Query schema params columns

428+ :: Query outer commons schemas params columns

350− -> Query schema params columns

429+ -> Query outer commons schemas params columns

351− -> Query schema params columns

430+ -> Query outer commons schemas params columns

352q1 `exceptAll` q2 = UnsafeQuery $

431q1 `exceptAll` q2 = UnsafeQuery $

353− parenthesized (renderQuery q1)

432+ parenthesized (renderSQL q1)

354 <+> "EXCEPT" <+> "ALL"

433 <+> "EXCEPT" <+> "ALL"

355− <+> parenthesized (renderQuery q2)

434+ <+> parenthesized (renderSQL q2)

356

435

357{-----------------------------------------

436{-----------------------------------------

358SELECT queries

437SELECT queries

359-----------------------------------------}

438-----------------------------------------}

360

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+

361-- | the `TableExpression` in the `select` command constructs an intermediate

525-- | the `TableExpression` in the `select` command constructs an intermediate

362-- virtual table by possibly combining tables, views, eliminating rows,

526-- virtual table by possibly combining tables, views, eliminating rows,

363-- grouping, etc. This table is finally passed on to processing by

527-- grouping, etc. This table is finally passed on to processing by

364−-- the select list. The select list determines which columns of

528+-- the select list. The `Selection` determines which columns of

365-- the intermediate table are actually output.

529-- the intermediate table are actually output.

366select

530select

367− :: SListI columns

531+ :: (SListI row, row ~ (x ': xs))

368− => NP (Aliased (Expression relations grouping params)) (column ': columns)

532+ => Selection outer commons grp schemas params from row

369− -- ^ select list

533+ -- ^ selection

370− -> TableExpression schema params relations grouping

534+ -> TableExpression outer commons grp schemas params from

371 -- ^ intermediate virtual table

535 -- ^ intermediate virtual table

372− -> Query schema params (column ': columns)

536+ -> Query outer commons schemas params row

373−select list rels = UnsafeQuery $

537+select selection tabexpr = UnsafeQuery $

374 "SELECT"

538 "SELECT"

375− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

539+ <+> renderSQL selection

376− <+> 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

377

552

378-- | After the select list has been processed, the result table can

553-- | After the select list has been processed, the result table can

379-- be subject to the elimination of duplicate rows using `selectDistinct`.

554-- be subject to the elimination of duplicate rows using `selectDistinct`.

380selectDistinct

555selectDistinct

381− :: SListI columns

556+ :: (SListI columns, columns ~ (col ': cols))

382− => NP (Aliased (Expression relations 'Ungrouped params)) (column ': columns)

557+ => Selection outer commons grp schemas params from columns

383− -- ^ select list

558+ -- ^ selection

384− -> TableExpression schema params relations 'Ungrouped

559+ -> TableExpression outer commons grp schemas params from

385 -- ^ intermediate virtual table

560 -- ^ intermediate virtual table

386− -> Query schema params (column ': columns)

561+ -> Query outer commons schemas params columns

387−selectDistinct list rels = UnsafeQuery $

562+selectDistinct selection tabexpr = UnsafeQuery $

388 "SELECT DISTINCT"

563 "SELECT DISTINCT"

389− <+> renderCommaSeparated (renderAliasedAs renderExpression) list

564+ <+> renderSQL selection

390− <+> renderTableExpression rels

565+ <+> renderSQL tabexpr

391−

566+

392−-- | The simplest kind of query is `selectStar` which emits all columns

567+-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead

393−-- that the table expression produces.

568+-- of a general `Selection`.

394−selectStar

569+selectDistinct_

395− :: HasUnique relation relations columns

570+ :: (SListI columns, columns ~ (col ': cols))

396− => TableExpression schema params relations 'Ungrouped

571+ => NP (Aliased (Expression outer commons grp schemas params from)) columns

397− -- ^ intermediate virtual table

572+ -- ^ select list

398− -> Query schema params columns

573+ -> TableExpression outer commons grp schemas params from

399−selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels

400−

401−-- | A `selectDistinctStar` emits all columns that the table expression

402−-- produces and eliminates duplicate rows.

403−selectDistinctStar

404− :: HasUnique relation relations columns

405− => TableExpression schema params relations 'Ungrouped

406 -- ^ intermediate virtual table

574 -- ^ intermediate virtual table

407− -> Query schema params columns

575+ -> Query outer commons schemas params columns

408−selectDistinctStar rels = UnsafeQuery $

576+selectDistinct_ = selectDistinct . List

409− "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels

577+

410−

578+{-|

411−-- | 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

412−-- for all the columns of a particular table, using `selectDotStar`.

580+the given expressions evaluate to equal. The DISTINCT ON expressions are

413−selectDotStar

581+interpreted using the same rules as for ORDER BY. ORDER BY is used to

414− :: Has relation relations columns

582+ensure that the desired row appears first.

415− => Alias relation

583+

416− -- ^ particular virtual subtable

584+The DISTINCT ON expression(s) must match the leftmost ORDER BY expression(s).

417− -> 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

418 -- ^ intermediate virtual table

598 -- ^ intermediate virtual table

419− -> Query schema params columns

599+ -> Query outer commons schemas params columns

420−selectDotStar rel relations = UnsafeQuery $

600+selectDistinctOn distincts selection tab = UnsafeQuery $

421− "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression relations

601+ "SELECT DISTINCT ON"

422−

602+ <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))

423−-- | A `selectDistinctDotStar` asks for all the columns of a particular table,

603+ <+> renderSQL selection

424−-- and eliminates duplicate rows.

604+ <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})

425−selectDistinctDotStar

605+ where

426− :: Has relation relations columns

606+ renderDistinctOn = \case

427− => Alias relation

607+ Asc expression -> renderSQL expression

428− -- ^ particular virtual table

608+ Desc expression -> renderSQL expression

429− -> 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

430 -- ^ intermediate virtual table

623 -- ^ intermediate virtual table

431− -> Query schema params columns

624+ -> Query outer commons schemas params columns

432−selectDistinctDotStar rel relations = UnsafeQuery $

625+selectDistinctOn_ distincts = selectDistinctOn distincts . List

433− "SELECT DISTINCT" <+> renderAlias rel <> ".*"

626+

434− <+> renderTableExpression relations

627+-- | `values` computes a row value or set of row values

628+-- specified by value expressions. It is most commonly used

629+-- to generate a “constant table” within a larger command,

630+-- but it can be used on its own.

631+--

632+-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]

633+-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query outer commons schemas '[] Row

634+-- >>> printSQL query

635+-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")

636+values

637+ :: SListI cols

638+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

639+ -> [NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols]

640+ -- ^ When more than one row is specified, all the rows must

641+ -- must have the same number of elements

642+ -> Query outer commons schemas params cols

643+values rw rws = UnsafeQuery $ "SELECT * FROM"

644+ <+> parenthesized (

645+ "VALUES"

646+ <+> commaSeparated

647+ ( parenthesized

648+ . renderCommaSeparated renderValuePart <$> rw:rws )

649+ ) <+> "AS t"

650+ <+> parenthesized (renderCommaSeparated renderAliasPart rw)

651+ where

652+ renderAliasPart, renderValuePart

653+ :: Aliased (Expression outer commons 'Ungrouped schemas params '[] ) ty -> ByteString

654+ renderAliasPart (_ `As` name) = renderSQL name

655+ renderValuePart (value `As` _) = renderSQL value

656+

657+-- | `values_` computes a row value or set of row values

658+-- specified by value expressions.

659+values_

660+ :: SListI cols

661+ => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols

662+ -- ^ one row of values

663+ -> Query outer commons schemas params cols

664+values_ rw = values rw []

435

665

436{-----------------------------------------

666{-----------------------------------------

437Table Expressions

667Table Expressions

@@ -444,15 +674,17 @@ Table Expressions

444-- 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

445-- 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.

446data TableExpression

676data TableExpression

447− (schema :: SchemaType)

677+ (outer :: FromType)

678+ (commons :: FromType)

679+ (grp :: Grouping)

680+ (schemas :: SchemasType)

448 (params :: [NullityType])

681 (params :: [NullityType])

449− (relations :: RelationsType)

682+ (from :: FromType)

450− (grouping :: Grouping)

451 = TableExpression

683 = TableExpression

452− { fromClause :: FromClause schema params relations

684+ { fromClause :: FromClause outer commons schemas params from

453 -- ^ 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

454 -- as a subquery, a @JOIN@ construct, or complex combinations of these.

686 -- as a subquery, a @JOIN@ construct, or complex combinations of these.

455− , whereClause :: [Condition relations 'Ungrouped params]

687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]

456 -- ^ optional search coditions, combined with `.&&`. After the processing

688 -- ^ optional search coditions, combined with `.&&`. After the processing

457 -- 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

458 -- is checked against the search condition. If the result of the

690 -- is checked against the search condition. If the result of the

@@ -461,20 +693,20 @@ data TableExpression

461 -- at least one column of the table generated in the `fromClause`;

693 -- at least one column of the table generated in the `fromClause`;

462 -- this is not required, but otherwise the WHERE clause will

694 -- this is not required, but otherwise the WHERE clause will

463 -- be fairly useless.

695 -- be fairly useless.

464− , groupByClause :: GroupByClause relations grouping

696+ , groupByClause :: GroupByClause grp from

465 -- ^ 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

466 -- 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

467 -- 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

468 -- 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

469 -- 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

470 -- and/or compute aggregates that apply to these groups.

702 -- and/or compute aggregates that apply to these groups.

471− , havingClause :: HavingClause relations grouping params

703+ , havingClause :: HavingClause outer commons grp schemas params from

472 -- ^ 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

473 -- are of interest, the `havingClause` can be used, much like a

705 -- are of interest, the `havingClause` can be used, much like a

474 -- `whereClause`, to eliminate groups from the result. Expressions in the

706 -- `whereClause`, to eliminate groups from the result. Expressions in the

475 -- `havingClause` can refer both to grouped expressions and to ungrouped

707 -- `havingClause` can refer both to grouped expressions and to ungrouped

476 -- expressions (which necessarily involve an aggregate function).

708 -- expressions (which necessarily involve an aggregate function).

477− , orderByClause :: [SortExpression relations grouping params]

709+ , orderByClause :: [SortExpression outer commons grp schemas params from]

478 -- ^ The `orderByClause` is for optional sorting. When more than one

710 -- ^ The `orderByClause` is for optional sorting. When more than one

479 -- `SortExpression` is specified, the later (right) values are used to sort

711 -- `SortExpression` is specified, the later (right) values are used to sort

480 -- rows that are equal according to the earlier (left) values.

712 -- rows that are equal according to the earlier (left) values.

@@ -484,72 +716,69 @@ data TableExpression

484 -- will be returned (but possibly fewer, if the query itself yields

716 -- will be returned (but possibly fewer, if the query itself yields

485 -- fewer rows).

717 -- fewer rows).

486 , offsetClause :: [Word64]

718 , offsetClause :: [Word64]

487− -- ^ The `offsetClause` is combined with `+` to give an offset count

719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count

488 -- 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

489 -- 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

490 -- is applied.

722 -- is applied.

491− }

723+ } deriving (GHC.Generic)

492

724

493-- | Render a `TableExpression`

725-- | Render a `TableExpression`

494−renderTableExpression

726+instance RenderSQL (TableExpression outer commons grp schemas params from) where

495− :: TableExpression schema params relations grouping

727+ renderSQL

496− -> ByteString

497−renderTableExpression

498− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

728+ (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

499− [ "FROM ", renderFromClause frm'

729+ [ "FROM ", renderSQL frm'

500− , renderWheres whs'

730+ , renderWheres whs'

501− , renderGroupByClause grps'

731+ , renderSQL grps'

502− , renderHavingClause hvs'

732+ , renderSQL hvs'

503− , renderOrderByClause srts'

733+ , renderOrderByClause srts'

504− , renderLimits lims'

734+ , renderLimits lims'

505− , renderOffsets offs'

735+ , renderOffsets offs' ]

506− ]

507− where

736+ where

508− renderWheres = \case

737+ renderWheres = \case

509− [] -> ""

738+ [] -> ""

510− wh:[] -> " WHERE" <+> renderExpression wh

739+ wh:[] -> " WHERE" <+> renderSQL wh

511− wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)

740+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

512− renderOrderByClause = \case

741+ renderOrderByClause = \case

513− [] -> ""

742+ [] -> ""

514− srts -> " ORDER BY"

743+ srts -> " ORDER BY"

515− <+> commaSeparated (renderSortExpression <$> srts)

744+ <+> commaSeparated (renderSQL <$> srts)

516− renderLimits = \case

745+ renderLimits = \case

517− [] -> ""

746+ [] -> ""

518− lims -> " LIMIT" <+> fromString (show (minimum lims))

747+ lims -> " LIMIT" <+> fromString (show (minimum lims))

519− renderOffsets = \case

748+ renderOffsets = \case

520− [] -> ""

749+ [] -> ""

521− offs -> " OFFSET" <+> fromString (show (sum offs))

750+ offs -> " OFFSET" <+> fromString (show (sum offs))

522

751

523-- | 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

524-- 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,

525-- 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_`,

526−-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

527-- 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.

528from

757from

529− :: FromClause schema params relations -- ^ table reference

758+ :: FromClause outer commons schemas params from -- ^ table reference

530− -> TableExpression schema params relations 'Ungrouped

759+ -> TableExpression outer commons 'Ungrouped schemas params from

531−from rels = TableExpression rels [] NoGroups NoHaving [] [] []

760+from tab = TableExpression tab [] noGroups NoHaving [] [] []

532

761

533-- | A `where_` is an endomorphism of `TableExpression`s which adds a

762-- | A `where_` is an endomorphism of `TableExpression`s which adds a

534-- search condition to the `whereClause`.

763-- search condition to the `whereClause`.

535where_

764where_

536− :: Condition relations 'Ungrouped params -- ^ filtering condition

765+ :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition

537− -> TableExpression schema params relations grouping

766+ -> TableExpression outer commons grp schemas params from

538− -> TableExpression schema params relations grouping

767+ -> TableExpression outer commons grp schemas params from

539where_ wh rels = rels {whereClause = wh : whereClause rels}

768where_ wh rels = rels {whereClause = wh : whereClause rels}

540

769

541−-- | A `group` is a transformation of `TableExpression`s which switches

770+-- | A `groupBy` is a transformation of `TableExpression`s which switches

542−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform

771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform

543-- a "grand total" aggregation query.

772-- a "grand total" aggregation query.

544−group

773+groupBy

545 :: SListI bys

774 :: SListI bys

546− => NP (By relations) bys -- ^ grouped columns

775+ => NP (By from) bys -- ^ grouped columns

547− -> TableExpression schema params relations 'Ungrouped

776+ -> TableExpression outer commons 'Ungrouped schemas params from

548− -> TableExpression schema params relations ('Grouped bys)

777+ -> TableExpression outer commons ('Grouped bys) schemas params from

549−group bys rels = TableExpression

778+groupBy bys rels = TableExpression

550 { fromClause = fromClause rels

779 { fromClause = fromClause rels

551 , whereClause = whereClause rels

780 , whereClause = whereClause rels

552− , groupByClause = Group bys

781+ , groupByClause = group bys

553 , havingClause = Having []

782 , havingClause = Having []

554 , orderByClause = []

783 , orderByClause = []

555 , limitClause = limitClause rels

784 , limitClause = limitClause rels

@@ -559,34 +788,29 @@ group bys rels = TableExpression

559-- | A `having` is an endomorphism of `TableExpression`s which adds a

788-- | A `having` is an endomorphism of `TableExpression`s which adds a

560-- search condition to the `havingClause`.

789-- search condition to the `havingClause`.

561having

790having

562− :: Condition relations ('Grouped bys) params -- ^ having condition

791+ :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition

563− -> TableExpression schema params relations ('Grouped bys)

792+ -> TableExpression outer commons ('Grouped bys) schemas params from

564− -> TableExpression schema params relations ('Grouped bys)

793+ -> TableExpression outer commons ('Grouped bys) schemas params from

565having hv rels = rels

794having hv rels = rels

566 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

567

796

568−-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an

797+instance OrderBy TableExpression where

569−-- ordering to the right of the `orderByClause`.

570−orderBy

571− :: [SortExpression relations grouping params] -- ^ sort expressions

572− -> TableExpression schema params relations grouping

573− -> TableExpression schema params relations grouping

574−orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

575

799

576-- | 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

577-- `limitClause`.

801-- `limitClause`.

578limit

802limit

579 :: Word64 -- ^ limit parameter

803 :: Word64 -- ^ limit parameter

580− -> TableExpression schema params relations grouping

804+ -> TableExpression outer commons grp schemas params from

581− -> TableExpression schema params relations grouping

805+ -> TableExpression outer commons grp schemas params from

582limit lim rels = rels {limitClause = lim : limitClause rels}

806limit lim rels = rels {limitClause = lim : limitClause rels}

583

807

584-- | 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

585-- `offsetClause`.

809-- `offsetClause`.

586offset

810offset

587 :: Word64 -- ^ offset parameter

811 :: Word64 -- ^ offset parameter

588− -> TableExpression schema params relations grouping

812+ -> TableExpression outer commons grp schemas params from

589− -> TableExpression schema params relations grouping

813+ -> TableExpression outer commons grp schemas params from

590offset off rels = rels {offsetClause = off : offsetClause rels}

814offset off rels = rels {offsetClause = off : offsetClause rels}

591

815

592{-----------------------------------------

816{-----------------------------------------

@@ -597,57 +821,76 @@ FROM clauses

597A `FromClause` can be a table name, or a derived table such

821A `FromClause` can be a table name, or a derived table such

598as a subquery, a @JOIN@ construct, or complex combinations of these.

822as a subquery, a @JOIN@ construct, or complex combinations of these.

599-}

823-}

600−newtype FromClause schema params relations

824+newtype FromClause outer commons schemas params from

601 = UnsafeFromClause { renderFromClause :: ByteString }

825 = UnsafeFromClause { renderFromClause :: ByteString }

602 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

603

829

604−-- | A real `table` is a table from the schema.

830+-- | A real `table` is a table from the database.

605table

831table

606− :: Aliased (Table schema) table

832+ :: (Has sch schemas schema, Has tab schema ('Table table))

833+ => Aliased (QualifiedAlias sch) (alias ::: tab)

607− -> FromClause schema params '[table]

834+ -> FromClause outer commons schemas params '[alias ::: TableToRow table]

608−table = UnsafeFromClause . renderAliasedAs renderTable

835+table (tab `As` alias) = UnsafeFromClause $

836+ renderSQL tab <+> "AS" <+> renderSQL alias

609

837

610-- | `subquery` derives a table from a `Query`.

838-- | `subquery` derives a table from a `Query`.

611subquery

839subquery

612− :: Aliased (Query schema params) table

840+ :: Aliased (Query outer commons schemas params) query

613− -> FromClause schema params '[table]

841+ -> FromClause outer commons schemas params '[query]

614−subquery = UnsafeFromClause . renderAliasedAs (parenthesized . renderQuery)

842+subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)

615

843

616-- | `view` derives a table from a `View`.

844-- | `view` derives a table from a `View`.

617view

845view

618− :: Aliased (View schema) table

846+ :: (Has sch schemas schema, Has vw schema ('View view))

847+ => Aliased (QualifiedAlias sch) (alias ::: vw)

619− -> FromClause schema params '[table]

848+ -> FromClause outer commons schemas params '[alias ::: view]

620−view = UnsafeFromClause . renderAliasedAs renderView

849+view (vw `As` alias) = UnsafeFromClause $

621−

850+ renderSQL vw <+> "AS" <+> renderSQL alias

851+

852+-- | `common` derives a table from a common table expression.

853+common

854+ :: Has cte commons common

855+ => Aliased Alias (alias ::: cte)

856+ -> FromClause outer commons schemas params '[alias ::: common]

857+common (cte `As` alias) = UnsafeFromClause $

858+ renderSQL cte <+> "AS" <+> renderSQL alias

859+

860+instance Additional (FromClause outer commons schemas params) where

861+ also right left = UnsafeFromClause $

862+ renderSQL left <> ", " <> renderSQL right

863+

864+{- |

622−{- | @left & crossJoin right@. For every possible combination of rows from

865+@left & crossJoin right@. For every possible combination of rows from

623− @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

624− 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@.

625− 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

626− have @n * m@ rows.

869+have @n * m@ rows.

627-}

870-}

628crossJoin

871crossJoin

629− :: FromClause schema params right

872+ :: FromClause outer commons schemas params right

630 -- ^ right

873 -- ^ right

631− -> FromClause schema params left

874+ -> FromClause outer commons schemas params left

632 -- ^ left

875 -- ^ left

633− -> FromClause schema params (Join left right)

876+ -> FromClause outer commons schemas params (Join left right)

634crossJoin right left = UnsafeFromClause $

877crossJoin right left = UnsafeFromClause $

635− renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right

878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right

636

879

637{- | @left & innerJoin right on@. The joined table is filtered by

880{- | @left & innerJoin right on@. The joined table is filtered by

638the @on@ condition.

881the @on@ condition.

639-}

882-}

640innerJoin

883innerJoin

641− :: FromClause schema params right

884+ :: FromClause outer commons schemas params right

642 -- ^ right

885 -- ^ right

643− -> Condition (Join left right) 'Ungrouped params

886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

644 -- ^ @on@ condition

887 -- ^ @on@ condition

645− -> FromClause schema params left

888+ -> FromClause outer commons schemas params left

646 -- ^ left

889 -- ^ left

647− -> FromClause schema params (Join left right)

890+ -> FromClause outer commons schemas params (Join left right)

648innerJoin right on left = UnsafeFromClause $

891innerJoin right on left = UnsafeFromClause $

649− renderFromClause left <+> "INNER JOIN" <+> renderFromClause right

892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right

650− <+> "ON" <+> renderExpression on

893+ <+> "ON" <+> renderSQL on

651

894

652{- | @left & leftOuterJoin right on@. First, an inner join is performed.

895{- | @left & leftOuterJoin right on@. First, an inner join is performed.

653 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

@@ -655,16 +898,16 @@ innerJoin right on left = UnsafeFromClause $

655 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@.

656-}

899-}

657leftOuterJoin

900leftOuterJoin

658− :: FromClause schema params right

901+ :: FromClause outer commons schemas params right

659 -- ^ right

902 -- ^ right

660− -> Condition (Join left right) 'Ungrouped params

903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

661 -- ^ @on@ condition

904 -- ^ @on@ condition

662− -> FromClause schema params left

905+ -> FromClause outer commons schemas params left

663 -- ^ left

906 -- ^ left

664− -> FromClause schema params (Join left (NullifyRelations right))

907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))

665leftOuterJoin right on left = UnsafeFromClause $

908leftOuterJoin right on left = UnsafeFromClause $

666− renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right

909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right

667− <+> "ON" <+> renderExpression on

910+ <+> "ON" <+> renderSQL on

668

911

669{- | @left & rightOuterJoin right on@. First, an inner join is performed.

912{- | @left & rightOuterJoin right on@. First, an inner join is performed.

670 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

@@ -673,16 +916,16 @@ leftOuterJoin right on left = UnsafeFromClause $

673 have a row for each row in @right@.

916 have a row for each row in @right@.

674-}

917-}

675rightOuterJoin

918rightOuterJoin

676− :: FromClause schema params right

919+ :: FromClause outer commons schemas params right

677 -- ^ right

920 -- ^ right

678− -> Condition (Join left right) 'Ungrouped params

921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

679 -- ^ @on@ condition

922 -- ^ @on@ condition

680− -> FromClause schema params left

923+ -> FromClause outer commons schemas params left

681 -- ^ left

924 -- ^ left

682− -> FromClause schema params (Join (NullifyRelations left) right)

925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)

683rightOuterJoin right on left = UnsafeFromClause $

926rightOuterJoin right on left = UnsafeFromClause $

684− renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right

927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right

685− <+> "ON" <+> renderExpression on

928+ <+> "ON" <+> renderSQL on

686

929

687{- | @left & fullOuterJoin right on@. First, an inner join is performed.

930{- | @left & fullOuterJoin right on@. First, an inner join is performed.

688 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

@@ -692,47 +935,56 @@ rightOuterJoin right on left = UnsafeFromClause $

692 is added.

935 is added.

693-}

936-}

694fullOuterJoin

937fullOuterJoin

695− :: FromClause schema params right

938+ :: FromClause outer commons schemas params right

696 -- ^ right

939 -- ^ right

697− -> Condition (Join left right) 'Ungrouped params

940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

698 -- ^ @on@ condition

941 -- ^ @on@ condition

699− -> FromClause schema params left

942+ -> FromClause outer commons schemas params left

700 -- ^ left

943 -- ^ left

701− -> FromClause schema params

944+ -> FromClause outer commons schemas params

702− (Join (NullifyRelations left) (NullifyRelations right))

945+ (Join (NullifyFrom left) (NullifyFrom right))

703fullOuterJoin right on left = UnsafeFromClause $

946fullOuterJoin right on left = UnsafeFromClause $

704− renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right

947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right

705− <+> "ON" <+> renderExpression on

948+ <+> "ON" <+> renderSQL on

706

949

707{-----------------------------------------

950{-----------------------------------------

708Grouping

951Grouping

709-----------------------------------------}

952-----------------------------------------}

710

953

711−-- | `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

712-- 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

713-- in all the columns listed. @By \#col@ will reference an unambiguous

956-- in all the columns listed. @By \#col@ will reference an unambiguous

714-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

715-- qualified column @tab.col@.

958-- qualified column @tab.col@.

716data By

959data By

717− (relations :: RelationsType)

960+ (from :: FromType)

718 (by :: (Symbol,Symbol)) where

961 (by :: (Symbol,Symbol)) where

719− By

962+ By1

720− :: (HasUnique relation relations columns, Has column columns ty)

963+ :: (HasUnique table from columns, Has column columns ty)

721 => Alias column

964 => Alias column

722− -> By relations '(relation, column)

965+ -> By from '(table, column)

723 By2

966 By2

724− :: (Has relation relations columns, Has column columns ty)

967+ :: (Has table from columns, Has column columns ty)

968+ => Alias table

725− => (Alias relation, Alias column)

969+ -> Alias column

726− -> By relations '(relation, column)

970+ -> By from '(table, column)

727−deriving instance Show (By relations by)

971+deriving instance Show (By from by)

728−deriving instance Eq (By relations by)

972+deriving instance Eq (By from by)

729−deriving instance Ord (By relations by)

973+deriving instance Ord (By from by)

730−

974+instance RenderSQL (By from by) where

731−-- | Renders a `By`.

975+ renderSQL = \case

732−renderBy :: By relations by -> ByteString

733−renderBy = \case

734− By column -> renderAlias column

976+ By1 column -> renderSQL column

735− 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

736

988

737-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

738-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

@@ -740,82 +992,107 @@ renderBy = \case

740-- done on @NoGroups@ while all output `Expression`s must be aggregated

992-- done on @NoGroups@ while all output `Expression`s must be aggregated

741-- in @Group Nil@. In general, all output `Expression`s in the

993-- in @Group Nil@. In general, all output `Expression`s in the

742-- 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)

743−data GroupByClause relations grouping where

998+instance RenderSQL (GroupByClause grp from) where

999+ renderSQL = renderGroupByClause

744− NoGroups :: GroupByClause relations 'Ungrouped

1000+noGroups :: GroupByClause 'Ungrouped from

745− Group

1001+noGroups = UnsafeGroupByClause ""

1002+group

746− :: SListI bys

1003+ :: SListI bys

747− => NP (By relations) bys

1004+ => NP (By from) bys

748− -> GroupByClause relations ('Grouped bys)

1005+ -> GroupByClause ('Grouped bys) from

749−

1006+group bys = UnsafeGroupByClause $ case bys of

750−-- | Renders a `GroupByClause`.

751−renderGroupByClause :: GroupByClause relations grouping -> ByteString

752−renderGroupByClause = \case

753− NoGroups -> ""

754− Group Nil -> ""

1007+ Nil -> ""

755− Group bys -> " GROUP BY" <+> renderCommaSeparated renderBy bys

1008+ bys' -> " GROUP BY" <+> renderCommaSeparated renderSQL bys'

756

1009

757-- | 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.

758-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

1011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

759-- `TableExpression` must use `Having` whose conditions are combined with

1012-- `TableExpression` must use `Having` whose conditions are combined with

760-- `.&&`.

1013-- `.&&`.

761−data HavingClause relations grouping params where

1014+data HavingClause outer commons grp schemas params from where

762− NoHaving :: HavingClause relations 'Ungrouped params

1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from

763 Having

1016 Having

764− :: [Condition relations ('Grouped bys) params]

1017+ :: [Condition outer commons ('Grouped bys) schemas params from]

765− -> HavingClause relations ('Grouped bys) params

1018+ -> HavingClause outer commons ('Grouped bys) schemas params from

766−deriving instance Show (HavingClause relations grouping params)

1019+deriving instance Show (HavingClause outer commons grp schemas params from)

767−deriving instance Eq (HavingClause relations grouping params)

1020+deriving instance Eq (HavingClause outer commons grp schemas params from)

768−deriving instance Ord (HavingClause relations grouping params)

1021+deriving instance Ord (HavingClause outer commons grp schemas params from)

769

1022

770-- | Render a `HavingClause`.

1023-- | Render a `HavingClause`.

771−renderHavingClause :: HavingClause relations grouping params -> ByteString

1024+instance RenderSQL (HavingClause outer commons grp schemas params from) where

772−renderHavingClause = \case

1025+ renderSQL = \case

773− NoHaving -> ""

1026+ NoHaving -> ""

774− Having [] -> ""

1027+ Having [] -> ""

775− Having conditions ->

1028+ Having conditions ->

776− " HAVING" <+> commaSeparated (renderExpression <$> conditions)

1029+ " HAVING" <+> commaSeparated (renderSQL <$> conditions)

777−

1030+

778−{-----------------------------------------

1031+-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.

779−Sorting

1032+data CommonTableExpression statement

780−-----------------------------------------}

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

781

1074

782−-- | `SortExpression`s are used by `sortBy` to optionally sort the results

1075+{- |

783−-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result

1076+>>> import Data.Monoid (Sum (..))

784−-- column to ascending or descending. Ascending order puts smaller values

1077+>>> import Data.Int (Int64)

785−-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,

1078+>>> :{

786−-- descending order is determined with the `.>` operator. `AscNullsFirst`,

1079+ let

787−-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to

1080+ query :: Query_ schema () (Sum Int64)

788−-- determine whether nulls appear before or after non-null values in the sort

1081+ query = withRecursive

789−-- ordering of a `Null` result column.

1082+ ( values_ ((1 & astype int) `as` #n)

790−data SortExpression relations grouping params where

1083+ `unionAll`

791− Asc

1084+ select_ ((#n + 1) `as` #n)

792− :: Expression relations grouping params ('NotNull ty)

1085+ (from (common #t) & where_ (#n .< 100)) `as` #t )

793− -> SortExpression relations grouping params

1086+ ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))

794− Desc

1087+ in printSQL query

795− :: Expression relations grouping params ('NotNull ty)

1088+:}

796− -> SortExpression relations grouping params

1089+WITH RECURSIVE "t" AS ((SELECT * FROM (VALUES ((1 :: int))) AS t ("n")) UNION ALL (SELECT ("n" + 1) AS "n" FROM "t" AS "t" WHERE ("n" < 100))) SELECT COALESCE(sum(ALL "n"), 0) AS "getSum" FROM "t" AS "t"

797− AscNullsFirst

1090+-}

798− :: Expression relations grouping params ('Null ty)

1091+withRecursive

799− -> SortExpression relations grouping params

1092+ :: Aliased (Query outer (recursive ': commons) schemas params) recursive

800− AscNullsLast

1093+ -> Query outer (recursive ': commons) schemas params row

801− :: Expression relations grouping params ('Null ty)

1094+ -> Query outer commons schemas params row

802− -> SortExpression relations grouping params

1095+withRecursive (recursive `As` cte) query = UnsafeQuery $

803− DescNullsFirst

1096+ "WITH RECURSIVE" <+> renderSQL cte

804− :: Expression relations grouping params ('Null ty)

1097+ <+> "AS" <+> parenthesized (renderSQL recursive)

805− -> SortExpression relations grouping params

1098+ <+> renderSQL query

806− DescNullsLast

807− :: Expression relations grouping params ('Null ty)

808− -> SortExpression relations grouping params

809−deriving instance Show (SortExpression relations grouping params)

810−

811−-- | Render a `SortExpression`.

812−renderSortExpression :: SortExpression relations grouping params -> ByteString

813−renderSortExpression = \case

814− Asc expression -> renderExpression expression <+> "ASC"

815− Desc expression -> renderExpression expression <+> "DESC"

816− AscNullsFirst expression -> renderExpression expression

817− <+> "ASC NULLS FIRST"

818− DescNullsFirst expression -> renderExpression expression

819− <+> "DESC NULLS FIRST"

820− AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"

821− DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"

squeal-postgresql/src/Squeal/PostgreSQL/Render.hs+71−6

@@ -9,7 +9,11 @@ Rendering helper functions.

9-}

11{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , FlexibleContexts

15+ , LambdaCase

12− MagicHash

16+ , MagicHash

13 , OverloadedStrings

17 , OverloadedStrings

14 , PolyKinds

18 , PolyKinds

15 , RankNTypes

19 , RankNTypes

@@ -19,30 +23,48 @@ Rendering helper functions.

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

40+ , renderSymbol

29 ) where

41 ) where

43+import Control.Monad.IO.Class (MonadIO (..))

31import Data.ByteString (ByteString)

44import Data.ByteString (ByteString)

32−import Data.Maybe

45+import Data.Maybe (catMaybes)

33import Data.Monoid ((<>))

46import Data.Monoid ((<>))

47+import Data.Text (Text)

34import Generics.SOP

48import Generics.SOP

35import GHC.Exts

49import GHC.Exts

36−import GHC.TypeLits

50+import GHC.TypeLits hiding (Text)

52+import qualified Data.Text as Text

53+import qualified Data.Text.Encoding as Text

38import qualified Data.ByteString as ByteString

54import qualified Data.ByteString as ByteString

55+import qualified Data.ByteString.Char8 as Char8

40-- | Parenthesize a `ByteString`.

57-- | Parenthesize a `ByteString`.

41parenthesized :: ByteString -> ByteString

58parenthesized :: ByteString -> ByteString

42parenthesized str = "(" <> str <> ")"

59parenthesized str = "(" <> str <> ")"

61+-- | Square bracket a `ByteString`

62+bracketed :: ByteString -> ByteString

63+bracketed str = "[" <> str <> "]"

64+

44-- | Concatenate two `ByteString`s with a space between.

65-- | Concatenate two `ByteString`s with a space between.

45(<+>) :: ByteString -> ByteString -> ByteString

66(<+>) :: ByteString -> ByteString -> ByteString

67+infixr 7 <+>

46str1 <+> str2 = str1 <> " " <> str2

68str1 <+> str2 = str1 <> " " <> str2

48-- | Comma separate a list of `ByteString`s.

70-- | Comma separate a list of `ByteString`s.

@@ -53,6 +75,15 @@ commaSeparated = ByteString.intercalate ", "

53doubleQuoted :: ByteString -> ByteString

75doubleQuoted :: ByteString -> ByteString

54doubleQuoted 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+

56-- | Comma separate the renderings of a heterogeneous list.

87-- | Comma separate the renderings of a heterogeneous list.

57renderCommaSeparated

88renderCommaSeparated

58 :: SListI xs

89 :: SListI xs

@@ -63,6 +94,16 @@ renderCommaSeparated render

63 . hcollapse

94 . hcollapse

64 . 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+

66-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

107-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

67-- `Nothing`s.

108-- `Nothing`s.

68renderCommaSeparatedMaybe

109renderCommaSeparatedMaybe

@@ -76,5 +117,29 @@ renderCommaSeparatedMaybe render

76 . hmap (K . render)

117 . hmap (K . render)

118

78-- | Render a promoted `Nat`.

119-- | Render a promoted `Nat`.

79−renderNat :: KnownNat n => proxy n -> ByteString

120+renderNat :: forall n. KnownNat n => ByteString

80−renderNat (_ :: proxy n) = fromString (show (natVal' (proxy# :: Proxy# n)))

121+renderNat = fromString (show (natVal' (proxy# :: Proxy# n)))

122+

123+-- | Render a promoted `Symbol`.

124+renderSymbol :: forall s. KnownSymbol s => ByteString

125+renderSymbol = fromString (symbolVal' (proxy# :: Proxy# s))

126+

127+-- | A class for rendering SQL

128+class RenderSQL sql where renderSQL :: sql -> ByteString

129+

130+-- | Print SQL.

131+printSQL :: (RenderSQL sql, MonadIO io) => sql -> io ()

132+printSQL = liftIO . Char8.putStrLn . renderSQL

133+

134+-- | `escape` a character to prevent injection

135+escape :: Char -> String

136+escape = \case

137+ '\NUL' -> "\\0"

138+ '\'' -> "''"

139+ '"' -> "\\\""

140+ '\b' -> "\\b"

141+ '\n' -> "\\n"

142+ '\r' -> "\\r"

143+ '\t' -> "\\t"

144+ '\\' -> "\\\\"

145+ c -> [c]

squeal-postgresql/src/Squeal/PostgreSQL/Schema.hs+345−383

@@ -1,33 +1,32 @@

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−A type-level DSL for kinds of PostgreSQL types, constraints, and aliases.

8+`Squeal.PostgreSQL.Schema` provides a type-level DSL for kinds of Postgres types,

9+tables, schema, constraints, aliases, enumerated labels, and groupings.

10+It also defines useful type families to operate on these. Finally,

11+it defines an embedding of Haskell types into Postgres types.

9-}

12-}

10−

11{-# LANGUAGE

13{-# LANGUAGE

12 AllowAmbiguousTypes

14 AllowAmbiguousTypes

13 , ConstraintKinds

15 , ConstraintKinds

14− , DataKinds

15 , DeriveAnyClass

16 , DeriveAnyClass

16− , DeriveDataTypeable

17 , DeriveGeneric

18 , FlexibleContexts

19 , FlexibleInstances

20 , FunctionalDependencies

21 , GADTs

22− , MagicHash

22+ , LambdaCase

23− , MultiParamTypeClasses

24 , OverloadedStrings

23 , OverloadedStrings

25− , PolyKinds

24+ , QuantifiedConstraints

26 , RankNTypes

25 , RankNTypes

27 , ScopedTypeVariables

26 , ScopedTypeVariables

28 , StandaloneDeriving

27 , StandaloneDeriving

29 , TypeApplications

28 , TypeApplications

30− , TypeFamilies

29+ , TypeFamilyDependencies

31 , TypeInType

30 , TypeInType

32 , TypeOperators

31 , TypeOperators

33 , UndecidableInstances

32 , UndecidableInstances

@@ -35,95 +34,85 @@ A type-level DSL for kinds of PostgreSQL types, constraints, and aliases.

35#-}

34#-}

37module Squeal.PostgreSQL.Schema

36module Squeal.PostgreSQL.Schema

38− ( -- * Types

37+ ( -- * Postgres Types

39 PGType (..)

38 PGType (..)

40− , HasOid (..)

41 , NullityType (..)

39 , NullityType (..)

40+ , RowType

41+ , FromType

42+ -- * Schema Types

42 , ColumnType

43 , ColumnType

43 , ColumnsType

44 , ColumnsType

44− , RelationType

45− , NilRelation

46− , RelationsType

47 , TableType

45 , TableType

48− , TablesType

46+ , SchemumType (..)

49− , NilTables

47+ , IndexType (..)

50− -- * Grouping

48+ , FunctionType

51− , Grouping (..)

49+ , OperatorType (..)

52− , GroupedBy

50+ , ReturnsType (..)

51+ , SchemaType

52+ , SchemasType

53+ , Public

53 -- * Constraints

54 -- * Constraints

54 , (:=>)

55 , (:=>)

55 , ColumnConstraint (..)

56 , ColumnConstraint (..)

56 , TableConstraint (..)

57 , TableConstraint (..)

57 , TableConstraints

58 , TableConstraints

58− , NilTableConstraints

59 , Uniquely

60− -- * Aliases

60+ -- * Enumerated Labels

61− , (:::)

61+ , IsPGlabel (..)

62− , Alias (Alias)

62+ , PGlabel (..)

63− , renderAlias

63+ -- * Data Definitions

64− , renderAliases

65− , Aliased (As)

66− , renderAliasedAs

67− , AliasesOf

68− , Has

69− , HasUnique

70− , HasAll

71− , IsLabel (..)

72− , IsQualified (..)

73− -- * Type Families

74− , Join

75 , Create

64 , Create

65+ , CreateIfNotExists

66+ , CreateOrReplace

76 , Drop

67 , Drop

68+ , DropSchemum

69+ , DropIfExists

70+ , DropSchemumIfExists

77 , Alter

71 , Alter

72+ , AlterIfExists

78 , Rename

73 , Rename

79− , Elem

74+ , RenameIfExists

80− , In

75+ , ConstraintInvolves

76+ , DropIfConstraintsInvolve

77+ , IsNotElem

78+ , AllUnique

79+ -- * Type Classifications

81 , PGNum

80 , PGNum

82 , PGIntegral

81 , PGIntegral

83 , PGFloating

82 , PGFloating

84 , PGTypeOf

83 , PGTypeOf

85− , SameTypes

84+ , PGJsonType

85+ , PGJsonKey

86 , SamePGType

87 , AllNotNull

88 , NotAllNull

89+ -- * Nullifications

89 , NullifyType

90 , NullifyType

90− , NullifyRelation

91+ , NullifyRow

91− , NullifyRelations

92+ , NullifyFrom

92− , ColumnsToRelation

93+ -- * Table Conversions

93− , RelationToColumns

94 , TableToColumns

95− , TablesToRelations

95+ , ColumnsToRow

96− , RelationsToTables

96+ , TableToRow

97− , ConstraintInvolves

98− , DropIfConstraintsInvolve

99− -- * Generics

100− , SameField

101− , SameFields

102− -- * Schema

103− , SchemumType (..)

104− , SchemaType

105− , With

106 ) where

97 ) where

107

108−import Control.DeepSeq

99+import Control.Category

109−import Data.ByteString

100+import Data.Kind

110import Data.Monoid hiding (All)

101import Data.Monoid hiding (All)

111−import Data.String

112−import Data.Word

113import Data.Type.Bool

102import Data.Type.Bool

114−import GHC.Exts

103+import Generics.SOP

115−import GHC.OverloadedLabels

116import GHC.TypeLits

104import GHC.TypeLits

105+import Prelude hiding (id, (.))

117

106

118−import qualified GHC.Generics as GHC

107+import Squeal.PostgreSQL.Alias

119−import qualified Generics.SOP as SOP

108+import Squeal.PostgreSQL.List

120−import qualified Generics.SOP.Type.Metadata as Type

121−

122import Squeal.PostgreSQL.Render

109import Squeal.PostgreSQL.Render

123

110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

124-- | `PGType` is the promoted datakind of PostgreSQL types.

114-- | `PGType` is the promoted datakind of PostgreSQL types.

125--

115--

126−-- >>> import Squeal.PostgreSQL.Schema

127-- >>> :kind 'PGbool

116-- >>> :kind 'PGbool

128-- 'PGbool :: PGType

117-- 'PGbool :: PGType

129data PGType

118data PGType

@@ -134,6 +123,7 @@ data PGType

134 | PGnumeric -- ^ arbitrary precision numeric type

123 | PGnumeric -- ^ arbitrary precision numeric type

135 | PGfloat4 -- ^ single precision floating-point number (4 bytes)

124 | PGfloat4 -- ^ single precision floating-point number (4 bytes)

136 | PGfloat8 -- ^ double precision floating-point number (8 bytes)

125 | PGfloat8 -- ^ double precision floating-point number (8 bytes)

126+ | PGmoney -- ^ currency amount

137 | PGchar Nat -- ^ fixed-length character string

127 | PGchar Nat -- ^ fixed-length character string

138 | PGvarchar Nat -- ^ variable-length character string

128 | PGvarchar Nat -- ^ variable-length character string

139 | PGtext -- ^ variable-length character string

129 | PGtext -- ^ variable-length character string

@@ -148,40 +138,16 @@ data PGType

148 | PGinet -- ^ IPv4 or IPv6 host address

138 | PGinet -- ^ IPv4 or IPv6 host address

149 | PGjson -- ^ textual JSON data

139 | PGjson -- ^ textual JSON data

150 | PGjsonb -- ^ binary JSON data, decomposed

140 | PGjsonb -- ^ binary JSON data, decomposed

151− | PGvararray PGType -- ^ variable length array

141+ | PGvararray NullityType -- ^ variable length array

152− | PGfixarray Nat PGType -- ^ fixed length array

142+ | PGfixarray [Nat] NullityType -- ^ fixed length array

153− | PGenum [Symbol]

143+ | PGenum [Symbol] -- ^ enumerated (enum) types are data types that comprise a static, ordered set of values.

154− | 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).

155 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types

149 | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types

156

150

157−-- | The object identifier of a `PGType`.

158−--

159−-- >>> :set -XTypeApplications

160−-- >>> oid @'PGbool

161−-- 16

162−class HasOid (ty :: PGType) where oid :: Word32

163−instance HasOid 'PGbool where oid = 16

164−instance HasOid 'PGint2 where oid = 21

165−instance HasOid 'PGint4 where oid = 23

166−instance HasOid 'PGint8 where oid = 20

167−instance HasOid 'PGnumeric where oid = 1700

168−instance HasOid 'PGfloat4 where oid = 700

169−instance HasOid 'PGfloat8 where oid = 701

170−instance HasOid ('PGchar n) where oid = 18

171−instance HasOid ('PGvarchar n) where oid = 1043

172−instance HasOid 'PGtext where oid = 25

173−instance HasOid 'PGbytea where oid = 17

174−instance HasOid 'PGtimestamp where oid = 1114

175−instance HasOid 'PGtimestamptz where oid = 1184

176−instance HasOid 'PGdate where oid = 1082

177−instance HasOid 'PGtime where oid = 1083

178−instance HasOid 'PGtimetz where oid = 1266

179−instance HasOid 'PGinterval where oid = 1186

180−instance HasOid 'PGuuid where oid = 2950

181−instance HasOid 'PGinet where oid = 869

182−instance HasOid 'PGjson where oid = 114

183−instance HasOid 'PGjsonb where oid = 3802

184−

185-- | `NullityType` encodes the potential presence or definite absence of a

151-- | `NullityType` encodes the potential presence or definite absence of a

186-- @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.

187--

153--

@@ -200,14 +166,6 @@ data NullityType

200type (:=>) constraint ty = '(constraint,ty)

166type (:=>) constraint ty = '(constraint,ty)

201infixr 7 :=>

167infixr 7 :=>

202

168

203−-- | The alias operator `:::` is like a promoted version of `As`,

204−-- a type level pair between

205−-- an alias and some type, like a column alias and either a `ColumnType` or

206−-- `NullityType` or a table alias and either a `TableType` or a `RelationType`

207−-- or a constraint alias and a `TableConstraint`.

208−type (:::) (alias :: Symbol) ty = '(alias,ty)

209−infixr 6 :::

210−

211-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.

169-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.

212-- A column can be assigned a default value.

170-- A column can be assigned a default value.

213-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also

171-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also

@@ -249,11 +207,14 @@ data TableConstraint

249 | PrimaryKey [Symbol]

207 | PrimaryKey [Symbol]

250 | ForeignKey [Symbol] Symbol [Symbol]

208 | ForeignKey [Symbol] Symbol [Symbol]

251

209

252−-- | 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+-}

253type TableConstraints = [(Symbol,TableConstraint)]

217type TableConstraints = [(Symbol,TableConstraint)]

254−-- | A monokinded empty `TableConstraints`.

255−type family NilTableConstraints :: TableConstraints where

256− NilTableConstraints = '[]

257

218

258-- | A `ForeignKey` must reference columns that either are

219-- | A `ForeignKey` must reference columns that either are

259-- a `PrimaryKey` or form a `Unique` constraint.

220-- a `PrimaryKey` or form a `Unique` constraint.

@@ -277,227 +238,65 @@ type family Uniquely

277-- :}

238-- :}

278type TableType = (TableConstraints,ColumnsType)

239type TableType = (TableConstraints,ColumnsType)

279

240

280−-- | `TablesType` is a row of `TableType`s, thought of as a union.

241+{- | A `RowType` is a row of `NullityType`. They correspond to Haskell

281−--

242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.

282−-- >>> :{

243+

283−-- type family Schema :: TablesType where

284−-- Schema =

285−-- '[ "users" :::

286−-- '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

287−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

288−-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext

289−-- , "vec" ::: 'NoDef :=> 'NotNull ('PGvararray 'PGint2)

290−-- ]

291−-- , "emails" :::

292−-- '[ "pk_emails" ::: 'PrimaryKey '["id"]

293−-- , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

294−-- ] :=>

295−-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

296−-- , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

297−-- , "email" ::: 'NoDef :=> 'Null 'PGtext

298−-- ]

299−-- ]

300−-- :}

301−type TablesType = [(Symbol,TableType)]

302−-- | A monokinded empty `TablesType`.

303−type family NilTables :: TablesType where NilTables = '[]

304−

305−-- | `RelationType` is a row of `NullityType`

306−--

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+:}

252+-}

315−type RelationType = [(Symbol,NullityType)]

253+type RowType = [(Symbol,NullityType)]

316−-- | A monokinded empty `RelationType`.

317−type family NilRelation :: RelationType where NilRelation = '[]

318−

319−-- | `RelationsType` is a row of `RelationType`s, thought of as a product.

320−type RelationsType = [(Symbol,RelationType)]

321−

322−-- | `ColumnsToRelation` removes column constraints.

323−type family ColumnsToRelation (columns :: ColumnsType) :: RelationType where

324− ColumnsToRelation '[] = '[]

325− ColumnsToRelation (column ::: constraint :=> ty ': columns) =

326− column ::: ty ': ColumnsToRelation columns

327

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+

328−-- | `RelationToColumns` adds `'NoDef` column constraints.

261+-- | `ColumnsToRow` removes column constraints.

329−type family RelationToColumns (relation :: RelationType) :: ColumnsType where

262+type family ColumnsToRow (columns :: ColumnsType) :: RowType where

330− RelationToColumns '[] = '[]

263+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': column5 ::: _ :=> ty5 ': columns) =

331− RelationToColumns (column ::: ty ': columns) =

264+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': ColumnsToRow columns

332− column ::: 'NoDef :=> ty ': RelationToColumns 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 '[] = '[]

333

276

334-- | `TableToColumns` removes table constraints.

277-- | `TableToColumns` removes table constraints.

335type family TableToColumns (table :: TableType) :: ColumnsType where

278type family TableToColumns (table :: TableType) :: ColumnsType where

336 TableToColumns (constraints :=> columns) = columns

279 TableToColumns (constraints :=> columns) = columns

337

280

338−-- | `TablesToRelations` removes both table and column constraints.

281+-- | Convert a table to a row type.

339−type family TablesToRelations (tables :: TablesType) :: RelationsType where

282+type family TableToRow (table :: TableType) :: RowType where

340− TablesToRelations '[] = '[]

283+ TableToRow tab = ColumnsToRow (TableToColumns tab)

341− TablesToRelations (alias ::: constraint :=> columns ': tables) =

284+

342− alias ::: ColumnsToRelation columns ': TablesToRelations tables

285+-- | Numeric Postgres types.

343−

344−-- | `RelationsToTables` adds both trivial table and column constraints.

345−type family RelationsToTables (tables :: RelationsType) :: TablesType where

346− RelationsToTables '[] = '[]

347− RelationsToTables (alias ::: columns ': relations) =

348− alias ::: '[] :=> RelationToColumns columns ': RelationsToTables relations

349−

350−-- | `Grouping` is an auxiliary namespace, created by

351−-- @GROUP BY@ clauses (`Squeal.PostgreSQL.Query.group`), and used

352−-- for typesafe aggregation

353−data Grouping

354− = Ungrouped -- ^ no aggregation permitted

355− | Grouped [(Symbol,Symbol)] -- ^ aggregation required for any column which is not grouped

356−

357−{- | A `GroupedBy` constraint indicates that a table qualified column is

358−a member of the auxiliary namespace created by @GROUP BY@ clauses and thus,

359−may be called in an output `Squeal.PostgreSQL.Expression.Expression` without aggregating.

360−-}

361−class (KnownSymbol relation, KnownSymbol column)

362− => GroupedBy relation column bys where

363−instance {-# OVERLAPPING #-} (KnownSymbol relation, KnownSymbol column)

364− => GroupedBy relation column ('(table,column) ': bys)

365−instance {-# OVERLAPPABLE #-}

366− ( KnownSymbol relation

367− , KnownSymbol column

368− , GroupedBy relation column bys

369− ) => GroupedBy relation column (tabcol ': bys)

370−

371−-- | `Alias`es are proxies for a type level string or `Symbol`

372−-- and have an `IsLabel` instance so that with @-XOverloadedLabels@

373−--

374−-- >>> :set -XOverloadedLabels

375−-- >>> #foobar :: Alias "foobar"

376−-- Alias

377−data Alias (alias :: Symbol) = Alias

378− deriving (Eq,GHC.Generic,Ord,Show,NFData)

379−instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where

380− fromLabel = Alias

381−instance aliases ~ '[alias] => IsLabel alias (SOP.NP Alias aliases) where

382− fromLabel = fromLabel SOP.:* SOP.Nil

383−

384−-- | >>> renderAlias #jimbob

385−-- "\"jimbob\""

386−renderAlias :: KnownSymbol alias => Alias alias -> ByteString

387−renderAlias = doubleQuoted . fromString . symbolVal

388−

389−-- | >>> import Generics.SOP (NP(..))

390−-- >>> renderAliases (#jimbob :* #kandi :* Nil)

391−-- ["\"jimbob\"","\"kandi\""]

392−renderAliases

393− :: SOP.All KnownSymbol aliases => SOP.NP Alias aliases -> [ByteString]

394−renderAliases = SOP.hcollapse

395− . SOP.hcmap (SOP.Proxy @KnownSymbol) (SOP.K . renderAlias)

396−

397−-- | The `As` operator is used to name an expression. `As` is like a demoted

398−-- version of `:::`.

399−--

400−-- >>> Just "hello" `As` #hi :: Aliased Maybe ("hi" ::: String)

401−-- As (Just "hello") Alias

402−data Aliased expression aliased where

403− As

404− :: KnownSymbol alias

405− => expression ty

406− -> Alias alias

407− -> Aliased expression (alias ::: ty)

408−deriving instance Show (expression ty)

409− => Show (Aliased expression (alias ::: ty))

410−deriving instance Eq (expression ty)

411− => Eq (Aliased expression (alias ::: ty))

412−deriving instance Ord (expression ty)

413− => Ord (Aliased expression (alias ::: ty))

414−

415−-- | >>> let renderMaybe = fromString . maybe "Nothing" (const "Just")

416−-- >>> renderAliasedAs renderMaybe (Just (3::Int) `As` #an_int)

417−-- "Just AS \"an_int\""

418−renderAliasedAs

419− :: (forall ty. expression ty -> ByteString)

420− -> Aliased expression aliased

421− -> ByteString

422−renderAliasedAs render (expression `As` alias) =

423− render expression <> " AS " <> renderAlias alias

424−

425−-- | `AliasesOf` retains the AliasesOf in a row.

426−type family AliasesOf aliaseds where

427− AliasesOf '[] = '[]

428− AliasesOf (alias ::: ty ': tys) = alias ': AliasesOf tys

429−

430−-- | @HasUnique alias fields field@ is a constraint that proves that

431−-- @fields@ is a singleton of @alias ::: field@.

432−type HasUnique alias fields field = fields ~ '[alias ::: field]

433−

434−-- | @Has alias fields field@ is a constraint that proves that

435−-- @fields@ has a field of @alias ::: field@.

436−class KnownSymbol alias =>

437− Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)

438− | alias fields -> field where

439−instance {-# OVERLAPPING #-} KnownSymbol alias

440− => Has alias (alias ::: field ': fields) field

441−instance {-# OVERLAPPABLE #-} (KnownSymbol alias, Has alias fields field)

442− => Has alias (field' ': fields) field

443−

444−class

445− ( SOP.All KnownSymbol aliases

446− ) => HasAll

447− (aliases :: [Symbol])

448− (fields :: [(Symbol,kind)])

449− (subfields :: [(Symbol,kind)])

450− | aliases fields -> subfields where

451−instance {-# OVERLAPPING #-} HasAll '[] fields '[]

452−instance {-# OVERLAPPABLE #-}

453− (Has alias fields field, HasAll aliases fields subfields)

454− => HasAll (alias ': aliases) fields (alias ::: field ': subfields)

455−

456−-- | Analagous to `IsLabel`, the constraint

457−-- `IsQualified` defines `!` for a column alias qualified

458−-- by a table alias.

459−class IsQualified table column expression where

460− (!) :: Alias table -> Alias column -> expression

461− infixl 9 !

462−instance IsQualified table column (Alias table, Alias column) where (!) = (,)

463−

464−-- | @Elem@ is a promoted `Data.List.elem`.

465−type family Elem x xs where

466− Elem x '[] = 'False

467− Elem x (x ': xs) = 'True

468− Elem x (_ ': xs) = Elem x xs

469−

470−-- | @In x xs@ is a constraint that proves that @x@ is in @xs@.

471−type family In x xs :: Constraint where In x xs = Elem x xs ~ 'True

472−

473−-- | `PGNum` is a constraint on `PGType` whose

474−-- `Squeal.PostgreSQL.Expression.Expression`s have a `Num` constraint.

475−type PGNum ty =

286+type PGNum =

476− In ty '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

287+ '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

477−

288+

478−-- | `PGFloating` is a constraint on `PGType` whose

289+-- | Floating Postgres types.

479−-- `Squeal.PostgreSQL.Expression.Expression`s

480−-- have `Fractional` and `Floating` constraints.

481−type PGFloating ty = In ty '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

290+type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

482−

291+

483−-- | `PGIntegral` is a constraint on `PGType` whose

292+-- | Integral Postgres types.

484−-- `Squeal.PostgreSQL.Expression.Expression`s

485−-- have `Squeal.PostgreSQL.Expression.div_` and

486−-- `Squeal.PostgreSQL.Expression.mod_` functions.

487−type PGIntegral ty = In ty '[ 'PGint2, 'PGint4, 'PGint8]

293+type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]

488

294

489-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

295-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

490type family PGTypeOf (ty :: NullityType) :: PGType where

296type family PGTypeOf (ty :: NullityType) :: PGType where

491 PGTypeOf (nullity pg) = pg

297 PGTypeOf (nullity pg) = pg

492

298

493−-- | `SameTypes` is a constraint that proves two `ColumnsType`s have the same

299+-- | Equality constraint on the underlying `PGType` of two columns.

494−-- length and the same `ColumnType`s.

495−type family SameTypes (columns0 :: ColumnsType) (columns1 :: ColumnsType)

496− :: Constraint where

497− SameTypes '[] '[] = ()

498− SameTypes (column0 ::: def0 :=> ty0 ': columns0) (column1 ::: def1 :=> ty1 ': columns1)

499− = (ty0 ~ ty1, SameTypes columns0 columns1)

500−

501class SamePGType

300class SamePGType

502 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where

301 (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where

503instance ty0 ~ ty1 => SamePGType

302instance ty0 ~ ty1 => SamePGType

@@ -506,101 +305,166 @@ instance ty0 ~ ty1 => SamePGType

506

305

507-- | `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.

508type 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

509 AllNotNull '[] = ()

314 AllNotNull '[] = ()

510− AllNotNull (column ::: def :=> 'NotNull ty ': columns) = AllNotNull columns

511

315

512-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

316-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

513-- @NOT NULL@.

317-- @NOT NULL@.

514type family NotAllNull (columns :: ColumnsType) :: Constraint where

318type family NotAllNull (columns :: ColumnsType) :: Constraint where

515− NotAllNull (column ::: def :=> 'NotNull ty ': columns) = ()

319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

322+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

323+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

324+ NotAllNull (_ ::: _ :=> 'NotNull _ ': _) = ()

516− NotAllNull (column ::: def :=> 'Null ty ': columns) = NotAllNull columns

325+ NotAllNull (_ ::: _ :=> 'Null _ ': columns) = NotAllNull columns

517−

326+

518−-- | `NullifyType` is an idempotent that nullifies a `ColumnType`.

327+-- | `NullifyType` is an idempotent that nullifies a `NullityType`.

519type family NullifyType (ty :: NullityType) :: NullityType where

328type family NullifyType (ty :: NullityType) :: NullityType where

520 NullifyType ('Null ty) = 'Null ty

329 NullifyType ('Null ty) = 'Null ty

521 NullifyType ('NotNull ty) = 'Null ty

330 NullifyType ('NotNull ty) = 'Null ty

522

331

523−-- | `NullifyRelation` is an idempotent that nullifies a `ColumnsType`.

332+-- | `NullifyRow` is an idempotent that nullifies a `RowType`.

524−type family NullifyRelation (columns :: RelationType) :: RelationType where

333+type family NullifyRow (columns :: RowType) :: RowType where

525− 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

526− NullifyRelation (column ::: ty ': columns) =

344+ NullifyRow (column ::: ty ': columns) =

527− column ::: NullifyType ty ': NullifyRelation columns

345+ column ::: NullifyType ty ': NullifyRow columns

528−

346+ NullifyRow '[] = '[]

347+

529−-- | `NullifyRelations` is an idempotent that nullifies a `RelationsType`

348+-- | `NullifyFrom` is an idempotent that nullifies a `FromType`

530-- 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

531-- in a `Squeal.PostgreSQL.Query.FromClause`.

350-- in a `Squeal.PostgreSQL.Query.FromClause`.

532−type family NullifyRelations (tables :: RelationsType) :: RelationsType where

351+type family NullifyFrom (tables :: FromType) :: FromType where

533− NullifyRelations '[] = '[]

352+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': table5 ::: columns5 ': tables) =

534− 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

535− table ::: NullifyRelation columns ': NullifyRelations tables

354+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': tables) =

536−

355+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns4 ': NullifyFrom tables

537−-- | `Join` is simply promoted `++` and is used in @JOIN@s in

356+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': tables) =

538−-- `Squeal.PostgreSQL.Query.FromClause`s.

357+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': NullifyFrom tables

539−type family Join xs ys where

358+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': tables) =

540− Join '[] ys = ys

359+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': NullifyFrom tables

541− 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 '[] = '[]

542

365

543-- | @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

544-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

367-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

545-- `Squeal.PostgreSQL.Definition.addColumn`.

368-- `Squeal.PostgreSQL.Definition.addColumn`.

546type family Create alias x xs where

369type family Create alias x xs where

547 Create alias x '[] = '[alias ::: x]

370 Create alias x '[] = '[alias ::: x]

371+ Create alias x (alias ::: y ': xs) = TypeError

372+ ('Text "Create: alias "

373+ ':<>: 'ShowType alias

374+ ':<>: 'Text "already exists")

548 Create alias y (x ': xs) = x ': Create alias y xs

375 Create alias y (x ': xs) = x ': Create alias y xs

549

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+

550-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

394-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

551-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

395-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

552-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

396-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

553type 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" )

554− Drop alias ((alias ::: x) ': xs) = xs

402+ Drop alias (alias ::: x ': xs) = xs

555 Drop alias (x ': xs) = x ': Drop alias xs

403 Drop alias (x ': xs) = x ': Drop alias xs

556

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+

557-- | @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@

558−-- 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`

559-- and `Squeal.PostgreSQL.Definition.alterColumn`.

439-- and `Squeal.PostgreSQL.Definition.alterColumn`.

560type 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" )

561 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

445 Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

562 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

446 Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

563

447

564−-- type family AddConstraint constraint ty where

448+type family AlterIfExists alias x xs where

565−-- AddConstraint constraint (constraints :=> ty)

449+ AlterIfExists alias x '[] = '[]

566−-- = AsSet (constraint ': constraints) :=> ty

450+ AlterIfExists alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

567−

451+ AlterIfExists alias x1 (x0 ': xs) = x0 ': AlterIfExists alias x1 xs

568−-- type family DeleteFromList (e :: elem) (list :: [elem]) where

569−-- DeleteFromList elem '[] = '[]

570−-- DeleteFromList elem (x ': xs) =

571−-- If (Cmp elem x == 'EQ) xs (x ': DeleteFromList elem xs)

572−

573−-- type family DropConstraint constraint ty where

574−-- DropConstraint constraint (constraints :=> ty)

575−-- = (AsSet (DeleteFromList constraint constraints)) :=> ty

576

452

577-- | @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@

578-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

454-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

579-- `Squeal.PostgreSQL.Definition.renameColumn`.

455-- `Squeal.PostgreSQL.Definition.renameColumn`.

580type 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" )

581 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

582 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

583

463

584−-- | A `SameField` constraint is an equality constraint on a

464+type family RenameIfExists alias0 alias1 xs where

585−-- `Generics.SOP.Type.Metadata.FieldInfo` and the column alias in a `:::` pair.

465+ RenameIfExists alias x '[] = '[]

586−class SameField

466+ RenameIfExists alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

587− (fieldInfo :: Type.FieldInfo) (fieldty :: (Symbol,NullityType)) where

467+ RenameIfExists alias0 alias1 (x ': xs) = x ': RenameIfExists alias0 alias1 xs

588−instance field ~ column => SameField ('Type.FieldInfo field) (column ::: ty)

589−

590−-- | A `SameFields` constraint proves that a

591−-- `Generics.SOP.Type.Metadata.DatatypeInfo` of a record type has the same

592−-- field names as the column AliasesOf of a `ColumnsType`.

593−type family SameFields

594− (datatypeInfo :: Type.DatatypeInfo) (columns :: RelationType)

595− :: Constraint where

596− SameFields

597− ('Type.ADT _module _datatype '[ 'Type.Record _constructor fields])

598− columns

599− = SOP.AllZip SameField fields columns

600− SameFields

601− ('Type.Newtype _module _datatype ('Type.Record _constructor fields))

602− columns

603− = SOP.AllZip SameField fields columns

604

468

605-- | Check if a `TableConstraint` involves a column

469-- | Check if a `TableConstraint` involves a column

606type family ConstraintInvolves column constraint where

470type family ConstraintInvolves column constraint where

@@ -618,17 +482,115 @@ type family DropIfConstraintsInvolve column constraints where

618 (DropIfConstraintsInvolve column constraints)

482 (DropIfConstraintsInvolve column constraints)

619 (alias ::: constraint ': DropIfConstraintsInvolve column constraints)

483 (alias ::: constraint ': DropIfConstraintsInvolve column constraints)

620

484

485+-- | A `SchemumType` is a user-defined type, either a `Table`,

486+-- `View` or `Typedef`.

621data SchemumType

487data SchemumType

622 = Table TableType

488 = Table TableType

623− | View RelationType

489+ | View RowType

624 | Typedef PGType

490 | Typedef PGType

625−

491+ | Index IndexType

492+ | Function FunctionType

493+ | Operator OperatorType

494+ | UnsafeSchemum Symbol

495+

496+type FunctionType = ([NullityType], ReturnsType)

497+

498+data IndexType

499+ = Btree

500+ | Hash

501+ | Gist

502+ | Spgist

503+ | Gin

504+ | Brin

505+

506+data ReturnsType

507+ = Returns NullityType

508+ | ReturnsTable RowType

509+

510+data OperatorType

511+ = BinaryOp NullityType NullityType NullityType

512+ | LeftOp NullityType NullityType

513+ | RightOp NullityType NullityType

514+

515+{- | The schema of a database consists of a list of aliased,

516+user-defined `SchemumType`s.

517+

518+>>> :{

519+type family Schema :: SchemaType where

520+ Schema =

521+ '[ "users" ::: 'Table (

522+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

523+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

524+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

525+ ])

526+ , "emails" ::: 'Table (

527+ '[ "pk_emails" ::: 'PrimaryKey '["id"]

528+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

529+ ] :=>

530+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

531+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

532+ , "email" ::: 'NoDef :=> 'Null 'PGtext

533+ ])

534+ ]

535+:}

536+-}

626type SchemaType = [(Symbol,SchemumType)]

537type SchemaType = [(Symbol,SchemumType)]

627

538

628−type family With

539+{- |

629− (relations :: RelationsType)

540+A database contains one or more named schemas, which in turn contain tables.

630− (schema :: SchemaType)

541+The same object name can be used in different schemas without conflict;

631− :: SchemaType where

542+for example, both schema1 and myschema can contain tables named mytable.

632− With '[] schema = schema

543+Unlike databases, schemas are not rigidly separated:

633− With (alias ::: rel ': rels) schema =

544+a user can access objects in any of the schemas in the database they are connected to,

634− alias ::: 'Table ('[] :=> RelationToColumns rel) ': With rels schema

545+if they have privileges to do so.

546+

547+There are several reasons why one might want to use schemas:

548+

549+ * To allow many users to use one database without interfering with each other.

550+ * To organize database objects into logical groups to make them more manageable.

551+ * Third-party applications can be put into separate schemas

552+ so they do not collide with the names of other objects.

553+-}

554+type SchemasType = [(Symbol,SchemaType)]

555+

556+-- | A type family to use for a single schema database.

557+type family Public (schema :: SchemaType) :: SchemasType

558+ where Public schema = '["public" ::: schema]

559+

560+-- | `IsPGlabel` looks very much like the `IsLabel` class. Whereas

561+-- the overloaded label, `fromLabel` is used for column references,

562+-- `label`s are used for enum terms. A `label` is called with

563+-- type application like `label @"beef"`.

564+class IsPGlabel (label :: Symbol) expr where label :: expr

565+instance label ~ label1

566+ => IsPGlabel label (PGlabel label1) where label = PGlabel

567+instance labels ~ '[label]

568+ => IsPGlabel label (NP PGlabel labels) where label = PGlabel :* Nil

569+-- | A `PGlabel` unit type with an `IsPGlabel` instance

570+data PGlabel (label :: Symbol) = PGlabel

571+instance KnownSymbol label => RenderSQL (PGlabel label) where

572+ renderSQL _ = "\'" <> renderSymbol @label <> "\'"

573+instance All KnownSymbol labels => RenderSQL (NP PGlabel labels) where

574+ renderSQL

575+ = commaSeparated

576+ . hcollapse

577+ . hcmap (Proxy @KnownSymbol) (K . renderSQL)

578+

579+-- | Is a type a valid JSON key?

580+type PGJsonKey = '[ 'PGint2, 'PGint4, 'PGtext ]

581+

582+-- | Is a type a valid JSON type?

583+type PGJsonType = '[ 'PGjson, 'PGjsonb ]

584+

585+-- | Utility class for `AllUnique` to provide nicer error messages.

586+class IsNotElem x isElem where

587+instance IsNotElem x 'False where

588+instance (TypeError ( 'Text "Cannot assign to "

589+ ':<>: 'ShowType alias

590+ ':<>: 'Text " more than once"))

591+ => IsNotElem '(alias, a) 'True where

592+

593+-- | No elem of @xs@ appears more than once, in the context of assignment.

594+class AllUnique (xs :: [(Symbol, a)]) where

595+instance AllUnique '[] where

596+instance (IsNotElem x (Elem x xs), AllUnique xs) => AllUnique (x ': xs) where

squeal-postgresql/src/Squeal/PostgreSQL/Transaction.hs+102−82

@@ -1,7 +1,7 @@

1{-|

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

@@ -10,14 +10,9 @@ Squeal transaction control language.

11{-# LANGUAGE

12 DataKinds

13− , EmptyCase

14 , FlexibleContexts

13 , FlexibleContexts

15− , FlexibleInstances

16 , LambdaCase

14 , LambdaCase

17 , OverloadedStrings

15 , OverloadedStrings

18− , MultiParamTypeClasses

19− , ScopedTypeVariables

20− , TypeFamilies

21 , TypeInType

16 , TypeInType

22#-}

17#-}

@@ -25,89 +20,114 @@ module Squeal.PostgreSQL.Transaction

25 ( -- * Transaction

20 ( -- * Transaction

26 transactionally

21 transactionally

27 , transactionally_

22 , transactionally_

23+ , transactionallyRetry

24+ , ephemerally

25+ , ephemerally_

28 , begin

26 , begin

29 , commit

27 , commit

30 , rollback

28 , rollback

31− , transactionallySchema

32− , transactionallySchema_

33 -- * Transaction Mode

29 -- * Transaction Mode

34 , TransactionMode (..)

30 , TransactionMode (..)

35 , defaultMode

31 , defaultMode

36 , longRunningMode

32 , longRunningMode

37 , IsolationLevel (..)

33 , IsolationLevel (..)

38− , renderIsolationLevel

39 , AccessMode (..)

34 , AccessMode (..)

40− , renderAccessMode

41 , DeferrableMode (..)

35 , DeferrableMode (..)

42− , renderDeferrableMode

43 ) where

36 ) where

45−import Control.Exception.Lifted

38+import UnliftIO

46−import Control.Monad.Base

47−import Control.Monad.Trans.Control

48−import Data.ByteString

49−import Data.Monoid

50−import Generics.SOP

51−

52−import qualified Database.PostgreSQL.LibPQ as LibPQ

54import Squeal.PostgreSQL.Manipulation

40import Squeal.PostgreSQL.Manipulation

55import Squeal.PostgreSQL.Render

41import Squeal.PostgreSQL.Render

56import Squeal.PostgreSQL.PQ

42import Squeal.PostgreSQL.PQ

57−import Squeal.PostgreSQL.Schema

59−-- | Run a schema invariant computation `transactionally`.

44+{- | Run a computation `transactionally`;

45+first `begin`,

46+then run the computation,

47+`onException` `rollback` and rethrow the exception,

48+otherwise `commit` and `return` the result.

49+-}

60transactionally

50transactionally

61− :: (MonadBaseControl IO tx, MonadPQ schema tx)

51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

62 => TransactionMode

52 => TransactionMode

63 -> tx x -- ^ run inside a transaction

53 -> tx x -- ^ run inside a transaction

64 -> tx x

54 -> tx x

65transactionally mode tx = mask $ \restore -> do

55transactionally mode tx = mask $ \restore -> do

66− _ <- begin mode

56+ manipulate_ $ begin mode

67− result <- restore tx `onException` rollback

57+ result <- restore tx `onException` (manipulate_ rollback)

68− _ <- commit

58+ manipulate_ commit

69 return result

59 return result

71−-- | Run a schema invariant computation `transactionally_` in `defaultMode`.

61+-- | Run a computation `transactionally_`, in `defaultMode`.

72transactionally_

62transactionally_

73− :: (MonadBaseControl IO tx, MonadPQ schema tx)

63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

74 => tx x -- ^ run inside a transaction

64 => tx x -- ^ run inside a transaction

75 -> tx x

65 -> tx x

76transactionally_ = transactionally defaultMode

66transactionally_ = transactionally defaultMode

78−-- | @BEGIN@ a transaction.

68+{- |

79−begin :: MonadPQ schema tx => TransactionMode -> tx (K Result NilRelation)

69+`transactionallyRetry` a computation;

80−begin mode = manipulate . UnsafeManipulation $

70+

81− "BEGIN" <+> renderTransactionMode mode <> ";"

71+* first `begin`,

72+* then `try` the computation,

73+ - if it raises a serialization failure then `rollback` and restart the transaction,

74+ - if it raises any other exception then `rollback` and rethrow the exception,

75+ - otherwise `commit` and `return` the result.

76+-}

77+transactionallyRetry

78+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

79+ => TransactionMode

80+ -> tx x -- ^ run inside a transaction

81+ -> tx x

82+transactionallyRetry mode tx = mask $ \restore ->

83+ loop . try $ do

84+ x <- restore tx

85+ manipulate_ commit

86+ return x

87+ where

88+ loop attempt = do

89+ manipulate_ $ begin mode

90+ attempt >>= \case

91+ Left (PQException (PQState _ (Just "40001") _)) -> do

92+ manipulate_ rollback

93+ loop attempt

94+ Left err -> do

95+ manipulate_ rollback

96+ throwIO err

97+ Right x -> return x

98+

99+{- | Run a computation `ephemerally`;

100+Like `transactionally` but always `rollback`, useful in testing.

101+-}

102+ephemerally

103+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

104+ => TransactionMode

105+ -> tx x -- ^ run inside an ephemeral transaction

106+ -> tx x

107+ephemerally mode tx = mask $ \restore -> do

108+ manipulate_ $ begin mode

109+ result <- restore tx `onException` (manipulate_ rollback)

110+ manipulate_ rollback

111+ return result

112

83−-- | @COMMIT@ a schema invariant transaction.

113+{- | Run a computation `ephemerally` in `defaultMode`. -}

84−commit :: MonadPQ schema tx => tx (K Result NilRelation)

114+ephemerally_

85−commit = manipulate $ UnsafeManipulation "COMMIT;"

115+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

116+ => tx x -- ^ run inside an ephemeral transaction

117+ -> tx x

118+ephemerally_ = ephemerally defaultMode

119+

120+-- | @BEGIN@ a transaction.

121+begin :: TransactionMode -> Manipulation_ schemas () ()

122+begin mode = UnsafeManipulation $ "BEGIN" <+> renderSQL mode

123

87−-- | @ROLLBACK@ a schema invariant transaction.

124+-- | @COMMIT@ a transaction.

88−rollback :: MonadPQ schema tx => tx (K Result NilRelation)

125+commit :: Manipulation_ schemas () ()

89−rollback = manipulate $ UnsafeManipulation "ROLLBACK;"

126+commit = UnsafeManipulation "COMMIT"

127

91−-- | Run a schema changing computation `transactionallySchema`.

128+-- | @ROLLBACK@ a transaction.

92−transactionallySchema

129+rollback :: Manipulation_ schemas () ()

93− :: MonadBaseControl IO io

130+rollback = UnsafeManipulation "ROLLBACK"

94− => TransactionMode

95− -> PQ schema0 schema1 io x

96− -> PQ schema0 schema1 io x

97−transactionallySchema mode u = PQ $ \ conn -> mask $ \ restore -> do

98− _ <- liftBase . LibPQ.exec (unK conn) $

99− "BEGIN" <+> renderTransactionMode mode <> ";"

100− x <- restore (unPQ u conn)

101− `onException` (liftBase (LibPQ.exec (unK conn) "ROLLBACK"))

102− _ <- liftBase $ LibPQ.exec (unK conn) "COMMIT"

103− return x

104−

105−-- | Run a schema changing computation `transactionallySchema_` in `DefaultMode`.

106−transactionallySchema_

107− :: MonadBaseControl IO io

108− => PQ schema0 schema1 io x

109− -> PQ schema0 schema1 io x

110−transactionallySchema_ = transactionallySchema defaultMode

111

131

112-- | The available transaction characteristics are the transaction `IsolationLevel`,

132-- | The available transaction characteristics are the transaction `IsolationLevel`,

113-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

133-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

@@ -120,7 +140,7 @@ data TransactionMode = TransactionMode

120-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

140-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

121-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

141-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

122defaultMode :: TransactionMode

142defaultMode :: TransactionMode

123−defaultMode = TransactionMode Serializable ReadWrite NotDeferrable

143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable

124

144

125-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

145-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

126-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

146-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

@@ -129,12 +149,12 @@ longRunningMode :: TransactionMode

129longRunningMode = TransactionMode Serializable ReadOnly Deferrable

149longRunningMode = TransactionMode Serializable ReadOnly Deferrable

130

150

131-- | Render a `TransactionMode`.

151-- | Render a `TransactionMode`.

132−renderTransactionMode :: TransactionMode -> ByteString

152+instance RenderSQL TransactionMode where

133−renderTransactionMode mode =

153+ renderSQL mode =

134− "ISOLATION LEVEL"

154+ "ISOLATION LEVEL"

135− <+> renderIsolationLevel (isolationLevel mode)

155+ <+> renderSQL (isolationLevel mode)

136− <+> renderAccessMode (accessMode mode)

156+ <+> renderSQL (accessMode mode)

137− <+> renderDeferrableMode (deferrableMode mode)

157+ <+> renderSQL (deferrableMode mode)

138

158

139-- | The SQL standard defines four levels of transaction isolation.

159-- | The SQL standard defines four levels of transaction isolation.

140-- The most strict is `Serializable`, which is defined by the standard in a paragraph

160-- The most strict is `Serializable`, which is defined by the standard in a paragraph

@@ -165,32 +185,32 @@ data IsolationLevel

165 = Serializable

185 = Serializable

166 -- ^ Dirty read is not possible.

186 -- ^ Dirty read is not possible.

167 -- Nonrepeatable read is not possible.

187 -- Nonrepeatable read is not possible.

168− -- Phantom read is not possible.

188+ -- Phantom read is not possible.

169 -- Serialization anomaly is not possible.

189 -- Serialization anomaly is not possible.

170 | RepeatableRead

190 | RepeatableRead

171 -- ^ Dirty read is not possible.

191 -- ^ Dirty read is not possible.

172 -- Nonrepeatable read is not possible.

192 -- Nonrepeatable read is not possible.

173− -- Phantom read is not possible.

193+ -- Phantom read is not possible.

174 -- Serialization anomaly is possible.

194 -- Serialization anomaly is possible.

175 | ReadCommitted

195 | ReadCommitted

176 -- ^ Dirty read is not possible.

196 -- ^ Dirty read is not possible.

177 -- Nonrepeatable read is possible.

197 -- Nonrepeatable read is possible.

178− -- Phantom read is possible.

198+ -- Phantom read is possible.

179 -- Serialization anomaly is possible.

199 -- Serialization anomaly is possible.

180 | ReadUncommitted

200 | ReadUncommitted

181 -- ^ Dirty read is not possible.

201 -- ^ Dirty read is not possible.

182 -- Nonrepeatable read is possible.

202 -- Nonrepeatable read is possible.

183− -- Phantom read is possible.

203+ -- Phantom read is possible.

184 -- Serialization anomaly is possible.

204 -- Serialization anomaly is possible.

185 deriving (Show, Eq)

205 deriving (Show, Eq)

186

206

187-- | Render an `IsolationLevel`.

207-- | Render an `IsolationLevel`.

188−renderIsolationLevel :: IsolationLevel -> ByteString

208+instance RenderSQL IsolationLevel where

189−renderIsolationLevel = \case

209+ renderSQL = \case

190− Serializable -> "SERIALIZABLE"

210+ Serializable -> "SERIALIZABLE"

191− ReadCommitted -> "READ COMMITTED"

211+ ReadCommitted -> "READ COMMITTED"

192− ReadUncommitted -> "READ UNCOMMITTED"

212+ ReadUncommitted -> "READ UNCOMMITTED"

193− RepeatableRead -> "REPEATABLE READ"

213+ RepeatableRead -> "REPEATABLE READ"

194

214

195-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

215-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

196-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

216-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

@@ -207,10 +227,10 @@ data AccessMode

207 deriving (Show, Eq)

227 deriving (Show, Eq)

208

228

209-- | Render an `AccessMode`.

229-- | Render an `AccessMode`.

210−renderAccessMode :: AccessMode -> ByteString

230+instance RenderSQL AccessMode where

211−renderAccessMode = \case

231+ renderSQL = \case

212− ReadWrite -> "READ WRITE"

232+ ReadWrite -> "READ WRITE"

213− ReadOnly -> "READ ONLY"

233+ ReadOnly -> "READ ONLY"

214

234

215-- | The `Deferrable` transaction property has no effect

235-- | The `Deferrable` transaction property has no effect

216-- unless the transaction is also `Serializable` and `ReadOnly`.

236-- unless the transaction is also `Serializable` and `ReadOnly`.

@@ -226,7 +246,7 @@ data DeferrableMode

226 deriving (Show, Eq)

246 deriving (Show, Eq)

227

247

228-- | Render a `DeferrableMode`.

248-- | Render a `DeferrableMode`.

229−renderDeferrableMode :: DeferrableMode -> ByteString

249+instance RenderSQL DeferrableMode where

230−renderDeferrableMode = \case

250+ renderSQL = \case

231− Deferrable -> "DEFERRABLE"

251+ Deferrable -> "DEFERRABLE"

232− NotDeferrable -> "NOT DEFERRABLE"

252+ NotDeferrable -> "NOT DEFERRABLE"

squeal-postgresql/test/Doc.hsnew file+6

@@ -0,0 +1,6 @@

1+module Main (main) where

3+import Test.DocTest

5+main :: IO ()

6+main = doctest [ "-isrc", "src" ]

squeal-postgresql/test/DocTest.hsdeleted−18

@@ -1,18 +0,0 @@

1−module Main (main) where

2−

3−import Test.DocTest

4−

5−main :: IO ()

6−main = doctest

7− [ "-isrc"

8− , "src/Squeal/PostgreSQL.hs"

9− , "src/Squeal/PostgreSQL/Binary.hs"

10− , "src/Squeal/PostgreSQL/Definition.hs"

11− , "src/Squeal/PostgreSQL/Manipulation.hs"

12− , "src/Squeal/PostgreSQL/Query.hs"

13− , "src/Squeal/PostgreSQL/Expression.hs"

14− , "src/Squeal/PostgreSQL/PQ.hs"

15− , "src/Squeal/PostgreSQL/Migration.hs"

16− , "src/Squeal/PostgreSQL/Transaction.hs"

17− , "src/Squeal/PostgreSQL/Pool.hs"

18− ]

squeal-postgresql/test/Property.hsnew file+166

@@ -0,0 +1,166 @@

1+{-# LANGUAGE

2+ DataKinds

3+ , GADTs

4+ , LambdaCase

5+ , OverloadedLabels

6+ , OverloadedStrings

7+ , TypeApplications

8+ , TypeOperators

9+#-}

10+

11+module Main (main) where

12+

13+import Control.Monad.Trans

14+import Data.ByteString (ByteString)

15+import Data.ByteString.Char8 (unpack)

16+import Data.Scientific (fromFloatDigits)

17+import Data.Fixed (Fixed(MkFixed), Micro, Pico)

18+import Data.String (IsString(fromString))

19+import Data.Time

20+import Squeal.PostgreSQL hiding (check, defaultMain, Group)

21+import Hedgehog hiding (Range)

22+import qualified Hedgehog.Gen as Gen

23+import qualified Hedgehog.Main as Main

24+import qualified Hedgehog.Range as Range

25+

26+main :: IO ()

27+main = Main.defaultMain [checkSequential roundtrips]

28+

29+roundtrips :: Group

30+roundtrips = Group "roundtrips"

31+ [ roundtrip int2 genInt16

32+ , roundtrip int4 genInt32

33+ , roundtrip int8 genInt64

34+ , roundtrip bool Gen.bool

35+ , roundtrip numeric genScientific

36+ , roundtrip float4 genFloat

37+ , roundtrip float8 genDouble

38+ , roundtripOn normalizeTimeOfDay time genTimeOfDay

39+ -- , roundtrip timetz genTimeWithZone normalizeTimeWithZone

40+ , roundtripOn normalizeLocalTime timestamp genLocalTime

41+ , roundtrip timestamptz genUTCTime

42+ , roundtrip date genDay

43+ , roundtrip interval genDiffTime

44+ , roundtripOn normalizeIntRange int4range (genRange genInt32)

45+ , roundtripOn normalizeIntRange int8range (genRange genInt64)

46+ , roundtrip numrange (genRange genScientific)

47+ , roundtripOn (fmap normalizeLocalTime) tsrange (genRange genLocalTime)

48+ , roundtrip tstzrange (genRange genUTCTime)

49+ , roundtripOn normalizeIntRange daterange (genRange genDay)

50+ ]

51+ where

52+ genInt16 = Gen.int16 Range.exponentialBounded

53+ genInt32 = Gen.int32 Range.exponentialBounded

54+ genInt64 = Gen.int64 Range.exponentialBounded

55+ genScientific = fromFloatDigits <$> genFloat

56+ genPosFloat = Gen.float

57+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)

58+ genFloat = Gen.prune $ Gen.choice

59+ [ genPosFloat

60+ , negate <$> genPosFloat

61+ , Gen.element [0,1/0] ]

62+ genPosDouble = Gen.double

63+ (Range.exponentialFloatFrom 1 minPosFloat maxPosFloat)

64+ genDouble = Gen.prune $ Gen.choice

65+ [ genPosDouble

66+ , negate <$> genPosDouble

67+ , Gen.element [0,1/0] ]

68+ genRange gen = do

69+ lb <- gen

70+ ub <- Gen.filter (lb <) gen

71+ Gen.element

72+ [ Empty, singleton lb, whole

73+ , lb <=..<= ub , lb <=..< ub, lb <..<= ub, lb <..< ub

74+ , atLeast lb, moreThan lb, atMost ub, lessThan ub ]

75+ genDay = do

76+ y <- toInteger <$> Gen.int (Range.constant 2000 2019)

77+ m <- Gen.int (Range.constant 1 12)

78+ d <- Gen.int (Range.constant 1 28)

79+ return $ fromGregorian y m d

80+ genDiffTime = secondsToDiffTime . toInteger <$>

81+ Gen.int (Range.constant 0 86401)

82+ genUTCTime = UTCTime <$> genDay <*> genDiffTime

83+ genTimeOfDay = do

84+ h <- Gen.int (Range.constant 0 23)

85+ m <- Gen.int (Range.constant 0 59)

86+ s <- MkFixed . toInteger <$> Gen.int (Range.constant 0 59)

87+ return $ TimeOfDay h m s

88+ genLocalTime = LocalTime <$> genDay <*> genTimeOfDay

89+ -- genTimeZone = Gen.element $ map (read @TimeZone)

90+ -- [ "UTC", "UT", "GMT", "EST", "EDT", "CST"

91+ -- , "CDT", "MST", "MDT", "PST", "PDT" ]

92+ -- genTimeWithZone = (,) <$> genTimeOfDay <*> genTimeZone

93+

94+roundtrip

95+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)

96+ => TypeExpression schemas ('NotNull ty)

97+ -> Gen x

98+ -> (PropertyName, Property)

99+roundtrip = roundtripOn id

100+

101+roundtripOn

102+ :: (OidOf ty, ToParam x ty, FromValue ty x, Show x, Eq x)

103+ => (x -> x)

104+ -> TypeExpression schemas ('NotNull ty)

105+ -> Gen x

106+ -> (PropertyName, Property)

107+roundtripOn norm ty gen = propertyWithName $ do

108+ x <- forAll gen

109+ Just (Only y) <- lift . withConnection connectionString $

110+ firstRow =<< runQueryParams

111+ (values_ (parameter @1 ty `as` #fromOnly)) (Only x)

112+ norm x === y

113+ where

114+ propertyWithName prop =

115+ (fromString (unpack (renderSQL ty)), property prop)

116+

117+maxPosFloat :: RealFloat a => a

118+maxPosFloat = x

119+ where

120+ n = floatDigits x

121+ b = floatRadix x

122+ (_, u) = floatRange x

123+ x = encodeFloat (b^n - 1) (u - n)

124+

125+minPosFloat :: RealFloat a => a

126+minPosFloat = x

127+ where

128+ n = floatDigits x

129+ b = floatRadix x

130+ (l, _) = floatRange x

131+ x = encodeFloat (b^n - 1) (l - n - 1)

132+

133+connectionString :: ByteString

134+connectionString = "host=localhost port=5432 dbname=exampledb"

135+

136+normalizeIntRange :: (Enum int, Ord int) => Range int -> Range int

137+normalizeIntRange = \case

138+ Empty -> Empty

139+ NonEmpty l u ->

140+ let

141+ l' = normalizeL l

142+ u' = normalizeU u

143+ in if emptyNormalized l' u' then Empty else NonEmpty l' u'

144+ where

145+ normalizeL = \case

146+ Open l -> Closed (succ l)

147+ normalized -> normalized

148+ normalizeU = \case

149+ Closed u -> Open (succ u)

150+ normalized -> normalized

151+ emptyNormalized (Closed l) (Open u) = l >= u

152+ emptyNormalized _ _ = False

153+

154+normalizeTimeOfDay :: TimeOfDay -> TimeOfDay

155+normalizeTimeOfDay (TimeOfDay h m s) = TimeOfDay h m

156+ . fromRational @Pico

157+ . toRational @Micro

158+ . fromRational @Micro

159+ . toRational @Pico

160+ $ s

161+

162+normalizeLocalTime :: LocalTime -> LocalTime

163+normalizeLocalTime (LocalTime d t) = LocalTime d (normalizeTimeOfDay t)

164+

165+-- normalizeTimeWithZone :: (TimeOfDay, TimeZone) -> (TimeOfDay, TimeZone)

166+-- normalizeTimeWithZone (t, z) = (normalizeTimeOfDay t, z)

squeal-postgresql/test/Spec.hsnew file+136

@@ -0,0 +1,136 @@

1+{-# LANGUAGE

2+ DataKinds

3+ , DeriveAnyClass

4+ , DeriveGeneric

5+ , DerivingStrategies

6+ , DuplicateRecordFields

7+ , FlexibleContexts

8+ , OverloadedLabels

9+ , OverloadedLists

10+ , OverloadedStrings

11+ , TypeApplications

12+ , TypeFamilies

13+ , TypeInType

14+ , TypeOperators

15+#-}

16+

17+module Main (main) where

18+

19+import Control.Concurrent.Async (replicateConcurrently)

20+import Data.ByteString (ByteString)

21+import Data.Int (Int32)

22+import Data.Text (Text)

23+import Test.Hspec

24+

25+import qualified Generics.SOP as SOP

26+import qualified GHC.Generics as GHC

27+

28+import Squeal.PostgreSQL

29+

30+main :: IO ()

31+main = hspec spec

32+

33+type Schemas = Public

34+ '[ "users" ::: 'Table (

35+ '[ "pk_users" ::: 'PrimaryKey '["id"]

36+ , "unique_names" ::: 'Unique '["name"]

37+ ] :=>

38+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

39+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext ] ) ]

40+

41+data User = User

42+ { userName :: Text

43+ } deriving stock (Eq, Show, GHC.Generic)

44+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

45+

46+insertUser :: Manipulation_ Schemas User ()

47+insertUser = insertInto_ #users

48+ (Values_ (Default `as` #id :* Set (param @1) `as` #name))

49+

50+setup :: Definition (Public '[]) Schemas

51+setup =

52+ createTable #users

53+ ( serial `as` #id :*

54+ notNullable text `as` #name )

55+ ( primaryKey #id `as` #pk_users :*

56+ unique #name `as` #unique_names )

57+

58+teardown :: Definition Schemas (Public '[])

59+teardown = dropTable #users

60+

61+silence :: MonadPQ schemas pq => pq ()

62+silence = manipulate_ $

63+ UnsafeManipulation "SET client_min_messages TO WARNING;"

64+

65+setupDB :: IO ()

66+setupDB = withConnection connectionString $

67+ silence & pqThen (define setup)

68+

69+dropDB :: IO ()

70+dropDB = withConnection connectionString $

71+ silence & pqThen (define teardown)

72+

73+connectionString :: ByteString

74+connectionString = "host=localhost port=5432 dbname=exampledb"

75+

76+spec :: Spec

77+spec = before_ setupDB . after_ dropDB $ do

78+

79+ describe "Exceptions" $ do

80+

81+ let

82+ testUser = User "TestUser"

83+ newUser = manipulateParams_ insertUser

84+ insertUserTwice = newUser testUser >> newUser testUser

85+ err23505 = PQException $ PQState FatalError (Just "23505")

86+ (Just "ERROR: duplicate key value violates unique constraint \"unique_names\"\nDETAIL: Key (name)=(TestUser) already exists.\n")

87+

88+ it "should be thrown for constraint violation" $

89+ withConnection connectionString insertUserTwice

90+ `shouldThrow` (== err23505)

91+

92+ it "should be rethrown for constraint violation in a transaction" $

93+ withConnection connectionString (transactionally_ insertUserTwice)

94+ `shouldThrow` (== err23505)

95+

96+ describe "Pools" $

97+

98+ it "should manage concurrent transactions" $ do

99+ pool <- createConnectionPool

100+ "host=localhost port=5432 dbname=exampledb" 1 0.5 10

101+ let

102+ query :: Query_ (Public '[]) () (Only Char)

103+ query = values_ (literal 'a' `as` #fromOnly)

104+ session = usingConnectionPool pool . transactionally_ $ do

105+ result <- runQuery query

106+ Just (Only chr) <- firstRow result

107+ return chr

108+ chrs <- replicateConcurrently 10 session

109+ chrs `shouldSatisfy` all (== 'a')

110+

111+ describe "Ranges" $

112+

113+ it "should correctly decode ranges" $ do

114+

115+ rangesOut <- withConnection connectionString $ do

116+ let

117+ query :: Query_ (Public '[]) () (Only (Range Int32))

118+ query = values

119+ ( range int4range (atLeast 3) `as` #fromOnly )

120+ [ range int4range (3 <=..< 5) `as` #fromOnly

121+ , range int4range Empty `as` #fromOnly

122+ , range int4range whole `as` #fromOnly ]

123+ getRows =<< runQuery query

124+ (fromOnly <$> rangesOut :: [Range Int32]) `shouldBe`

125+ [ atLeast 3, 3 <=..< 5, Empty, whole ]

126+

127+ describe "Parameters" $ do

128+

129+ it "should run queries that don't reference all their parameters" $ do

130+

131+ out <- withConnection connectionString $ do

132+ let

133+ query :: Query_ (Public '[]) (Char,Int32) (Only Int32)

134+ query = values_ (param @2 `as` #fromOnly)

135+ firstRow =<< runQueryParams query ('a', 3 :: Int32)

136+ (fromOnly <$> out :: Maybe Int32) `shouldBe` Just 3

squeal-presentation-raveline.mdnew file+794

@@ -0,0 +1,794 @@

1+# Squeal

3+_A bridge between SQL and Haskell_

5+by [@Raveline](https://github.com/raveline)

7+---

9+# Rationale

10+

11+Using `postgresql-simple` you have a typical "Trial, error, despair" workflow:

12+

13+- Write query manually or semi-automatically

14+

15+- Write haskell code using the query

16+

17+- Pray that the query syntax is correct

18+

19+- Pray that it returns what you want

20+

21+- Realize the inefficiency of prayer when it comes to SQL

22+

23+- Iterate till it works

24+

25+---

26+

27+![Can't take this anymore](http://gif.eraveline.eu/static/img/0x16e.gif)

28+

29+---

30+

31+# Use your best friend: GHC

32+

33+Squeal provides several eDSL to make your SQL typesafe:

34+

35+- Type level eDSL to express schema;

36+

37+- Value level eDSL to manipulate schema (plus migration, yeehaw !);

38+

39+- Type level eDSL to express queries;

40+

41+- Value level eDSL to perform queries

42+

43+However, it's not an ORM. There's no caching, lazy loading - you retain control over your memory. Also, joins - and mostly aggregation after joins - have to be handled manually.

44+

45+---

46+

47+# Part I. Schema & migration

48+

49+---

50+

51+# The Schema

52+

53+- The schema will be used to validate _everything_: migration, queries, etc.

54+

55+- A schema is mostly a collection of tables.

56+

57+- In this presentation, we will create a very basic database modeling a parliament. We will store _members of parliament_ and _parliamentary groups_.

58+

59+- A simple Schema to represent a Parliament could be:

60+

61+```haskell

62+type Schema = '[ "mp" ::: 'Table MemberOfParliament

63+ , "groupp" ::: 'Table ParliamentGroup ]

64+```

65+

66+---

67+

68+> _note_ We need the `DataKinds` extension to be able to express heterogenous lists containing

69+> specific types like this one.

70+

71+> You can perfectly call your table "group" and not "groupp" even though it is a

72+> keyword in SQL - Squeal queries will be properly escaped.

73+

74+---

75+

76+# A small example

77+

78+```haskell

79+type ParliamentaryGroup =

80+ '[ "pk_groupp" ::: 'PrimaryKey '["groupp_id"]]

81+ :=>

82+ '[ "groupp_id" ::: 'NoDef :=> 'NotNull 'PGuuid

83+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext

84+ ]

85+```

86+

87+- That's a whole simple table defined in one go.

88+

89+- `:::` lets us define a column or a constraint.

90+

91+- `:=>` associates the constraints to the column.

92+

93+- Let's split constraints and column to study the syntax a bit more.

94+

95+---

96+

97+> _note_ We are using `:::` and `:=>` to quickly express associations when writing

98+> our schema. We need the `TypeOperators` extension.]

99+

100+---

101+

102+![What does this means ?!](http://gif.eraveline.eu/static/img/0x27e.gif)

103+

104+---

105+

106+# Defining a table

107+

108+```haskell

109+type MemberOfParliament =

110+ '[ "pk_mp" ::: 'PrimaryKey '["mp_id"]

111+ , "fk_mp_groupp" ::: 'ForeignKey '["mp_group"] "groupp" '["groupp_id"]

112+ ] :=> MpCols

113+```

114+

115+- A table is a collection of constraints associated to a collection of columns.

116+

117+- We defined a table named "mp".

118+

119+- It has a constraint named "pk_mp", defining its primary key on column "mp_id".

120+

121+- It has a constraint named "fk_mp_groupp" defining a foreign key on column "mg_group", connected to the column "groupp_id" of table "groupp".

122+

123+- These constraints will be associated to the columns defined in `MpCols`.

124+

125+---

126+

127+# Defining columns

128+

129+```haskell

130+type MpCols =

131+ '[ "mp_id" ::: 'NoDef :=> 'NotNull 'PGuuid

132+ , "first_name" ::: 'NoDef :=> 'NotNull 'PGtext

133+ , "last_name" ::: 'NoDef :=> 'NotNull 'PGtext

134+ ]

135+```

136+

137+- A listing of column associate, for each element:

138+

139+ * a name;

140+

141+ * the mention of an eventual default value;

142+

143+ * the nullability;

144+

145+ * the type (obviously).

146+

147+---

148+

149+> _note_ GHC is already helping. If I named the "mp_id" column differently,

150+> GHC would yell because I promised a primary key constraint on a column named `mp_id`, so there must be one.]

151+

152+---

153+

154+# Implementating the schema

155+

156+- We will carry this schema type pretty much everywhere.

157+

158+- But before we play with this schema, we need to implement it.

159+

160+---

161+

162+```haskell

163+setup :: Definition '[] Schema

164+setup =

165+ createTable #groupp

166+ ( notNullable uuid `as` #groupp_id

167+ :* notNullable text `as` #name)

168+ ( primaryKey #groupp_id `as` #pk_groupp )

169+ >>> createTable #mp

170+ ( notNullable uuid `as` #mp_id

171+ :* notNullable text `as` #first_name

172+ :* notNullable text `as` #last_name

173+ :* notNullable text `as` #mp_group)

174+ ( primaryKey #mp_id `as` #pk_mp

175+ :* foreignKey #mp_group #groupp #groupp_id

176+ OnDeleteCascade OnUpdateCascade

177+ `as` #fk_mp_groupp)

178+```

179+

180+---

181+

182+# Damn, that's verbose

183+

184+- Yes. But you need verbosity to get type safety.

185+

186+- On the plus side, it's fairly straightforward.

187+

188+- You use `:*` to compose the element of the heterogenous list of columns.

189+

190+- You use `>>>` to compose table creation.

191+

192+> _note_ The compiler will catch any mistype between Schema and

193+> definition; wrong nullability, wrong type, wrong name, etc.

194+

195+---

196+

197+> _note_ You'll also need `OverloadedLabels`, for naming stuff.

198+> This is mostly to avoid having to write manual proxies all

199+> the time and for convenience.

200+

201+---

202+

203+# Setting up the schema

204+

205+- Squeal comes with a very good migration manager, handling _upgrades_ AND

206+_downgrades_.

207+

208+- A migration is a simple type:

209+

210+```haskell

211+Migration io schema0 schema1

212+```

213+

214+- The first parameter is a BaseMonad (typically, IO).

215+

216+- The second parameter is "the current schema of your DB".

217+

218+- The last one is "what you will migrate to".

219+

220+- The `Definition` type used to define upgrade and downgrade functions use the

221+ same logic (from one schema to the other).

222+

223+---

224+

225+# Defining our first migration

226+

227+- We have the setup bit, we need the teardown:

228+

229+```haskell

230+tearDown :: Definition Schema '[]

231+tearDown = dropTable #mp >>> dropTable #groupp

232+```

233+

234+> _note_ GHC will also detect the _proper_ order of what you typed in

235+> downgrade and upgrade should there be any conflict (with foreign keys).

236+

237+```haskell

238+initDB :: Migration IO '[] Schema

239+initDB =

240+ Migration { name = "Schema creation"

241+ , up = void $ define setup

242+ , down = void $ define tearDown }

243+```

244+

245+---

246+

247+# Simple migrator example

248+

249+```haskell

250+main :: IO ()

251+main = do

252+ printSQL setup

253+ void $ withConnection connectionString $

254+ migrateUp $ single initDB

255+```

256+

257+- We print the migration query; you can do this for all queries generated through Squeal.

258+

259+- We use `migrateUp` to perform the migration.

260+

261+- You can run several migration at the same time, to run only one use `single`.

262+

263+---

264+

265+![That was easy](http://gif.eraveline.eu/static/img/0x47f.gif)

266+

267+---

268+

269+# Part II. Insertions

270+

271+---

272+

273+# Manipulations & Queries

274+

275+Besides the specific case of migration, you will mostly perform:

276+

277+- `Manipulation` : inserting, updating and deleting data.

278+

279+- `Query` : fetching data.

280+

281+- Both types are parametric over the same things:

282+

283+ * A schema

284+

285+ * Input parameters

286+

287+ * Output

288+

289+- Simplified, they look like this:

290+

291+```haskell

292+Manipulation schema params columns

293+

294+Query schema params columns

295+```

296+

297+

298+---

299+

300+# Our Haskell model

301+

302+```haskell

303+type Parliament = [Group]

304+

305+data Group =

306+ Group { name :: Text

307+ , members :: [MemberOfParliament] }

308+

309+data MemberOfParliament =

310+ MemberOfParliament { firstName :: Text

311+ , lastName :: Text }

312+```

313+

314+> _note_ We didn't use anything from Squeal.

315+> The model can be entirely separated from the persistence layer.

316+

317+---

318+

319+# Inserting a Parliamentary Group

320+

321+- A group is very simple: it's a uuid and a name. Let's define our params:

322+

323+```haskell

324+type GroupInsertionParams = '[ 'NotNull 'PGuuid

325+ , 'NotNull 'PGtext ]

326+```

327+

328+- Params are not named, but they are indexed. You just need nullability and type.

329+

330+---

331+

332+```haskell

333+groupInsertion :: Manipulation Schema GroupInsertionParams '[]

334+groupInsertion =

335+ insertRow_ #groupp ( Set (param @1) `as` #groupp_id

336+ :* Set (param @2) `as` #name )

337+```

338+

339+---

340+

341+- `TypeApplication` lets us use the index of parameters (counting from 1).

342+

343+- Once again: all this is checked by the compiler. Wrong name, wrong type... you'll get a compile error.

344+

345+- `insertRow_` is a simplified version of `insertRow`. `insertRow` lets you express a `RETURNING` clause and the expected behaviour in case of conflict.

346+

347+---

348+

349+_Inserting a Member of Parliament_

350+# Doing an INSERT INTO ... SELECT

351+

352+- We could create a naive query that takes MP uuid, first name, last name and group uuid...

353+

354+---

355+

356+- But that's boring. So let's use the `INSERT INTO ... SELECT`.

357+

358+---

359+

360+- We will build a query that will return as constants our MP's uuid, first name and last name...

361+

362+---

363+

364+- ... and fetch the uuid of a group given the name of the group.

365+

366+---

367+

368+- There's a `insertQuery` utility function for that. All we have to do is write the `select` !

369+

370+```haskell

371+mpInsertion :: Manipulation Schema MpParams '[]

372+mpInsertion =

373+ insertQuery_ #mp selectGroup -- we just have to write selectGroup !

374+```

375+

376+---

377+

378+_Inserting a Member of Parliament_

379+# The query type

380+

381+- A query looks just like a `Manipulation`:

382+

383+```haskell

384+Query schema params returns

385+```

386+

387+- Returns use a special syntax, that demands names, nullability and types:

388+

389+```haskell

390+type ExampleReturnType = '[ "some_column" ::: 'NotNull 'PGuuid

391+ , "other_column" ::: 'Null 'PGtext ]

392+```

393+

394+- It is not the same as the column definition we used in the schema. That one also expects that you specify, for each column, an eventual default:

395+

396+```haskell

397+type ExampleSchemaCols =

398+ '[ "some_column" ::: 'NoDef :=> 'NotNull 'PGuuid

399+ , "other_column" ::: 'NoDef :=> 'Null 'PGtext ]

400+```

401+

402+---

403+

404+_Inserting a Member of Parliament_

405+# Don't rewrite column definitions

406+

407+- We want our return type to be "all columns from table MP expressed as return type".

408+

409+- But we cannot reuse our neat `MpCols` alias, since the type do not match as we've just seen.

410+

411+- Hopefully, there's a neat Type Family that will let you convert any table you defined to the type of the equivalent row: `TableToRow`.

412+

413+- We finally have the signature for our SELECT query.

414+

415+```haskell

416+selectGroup :: Query Schema MpParams (TableToRow MemberOfParliament)

417+```

418+

419+---

420+

421+_Inserting a Member of Parliament_

422+# Our final Select query

423+

424+- Our intermediate query looks like this:

425+

426+```haskell

427+selectGroup =

428+ select

429+ ( param @1 `as` #mp_id

430+ :* param @2 `as` #first_name

431+ :* param @3 `as` #last_name

432+ :* #groupp ! #groupp_id `as` #mp_group

433+ )

434+ ( from (table #groupp)

435+ & where_ ( #groupp ! #name .== param @4 )

436+ )

437+```

438+

439+- The first three columns are constant defined through our params;

440+

441+- ... we alias the column name using `as`...

442+

443+- ... and when we need the result from the table we use the `#table ! #column` syntax.

444+

445+- We'll go back to the "from" block later.

446+

447+---

448+

449+# Dealing with the connection context

450+

451+- Queries are runned in a connection context:

452+

453+ * When dealing with a single-connection context, use the type `PQ`.

454+

455+ * When dealing with a pool of connection, use the type `PoolPQ`.

456+

457+- Or get rid of the context and use `mtl` style, with the typeclass `MonadPQ`.

458+

459+- We'll use that to demonstrate how to actually run our queries.

460+

461+---

462+

463+# Inserting a whole group

464+

465+```haskell

466+insertGroup :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()

467+insertGroup g@(Group name _) = do

468+ uuid' <- liftBase nextRandom

469+ void $ manipulateParams groupInsertion (uuid', name)

470+ insertMps g

471+```

472+

473+- Remember that we defined a group as a name and a list of MPs.

474+

475+- We are in `MonadBaseControl`, so we cannot use `liftIO`, we need `liftBase`.

476+

477+- To perform a simple insertion, use `manipulateParams`. It takes into parameter

478+instances of `ToParam`, but you will typically use tuples or Generic-SOP.

479+

480+---

481+

482+# Inserting a bunch of MPs

483+

484+```haskell

485+insertMps :: (MonadPQ Schema m, MonadBaseControl IO m) => Group -> m ()

486+insertMps (Group groupName mps) =

487+ let tuplify Mp{..} = (, firstName, lastName, groupName) <$> nextRandom

488+ params = traverse tuplify mps

489+ in void $ liftBase params >>= traversePrepared mpInsertion

490+```

491+

492+- This time, we want to do a `preparedStatement`. We'll use `traversePrepare`

493+which behaves like `manipulateParams`, but expect a list of `ToParam`

494+instances.

495+

496+- We build our tuple manually again, mostly because we want to generate UUID on

497+the fly and we don't want to have them in our model.

498+

499+---

500+

501+# Inserting a whole parliament

502+

503+```haskell

504+insertParliament ::

505+ (MonadPQ Schema m, MonadBaseControl IO m) => Parliament -> m ()

506+insertParliament = traverse_ insertGroup

507+```

508+

509+- That's simple enough !

510+

511+- If we want to be a bit safer, though, we can wrap this call in a

512+`transactionally_` function, which will put all that in a transaction.

513+

514+---

515+

516+![Very simple](https://media1.tenor.com/images/0188c63209aced59f1583e1ca94e509e/tenor.gif?itemid=3550689)

517+

518+

519+---

520+

521+# Part III. Selects

522+

523+---

524+

525+# Composable queries

526+

527+- Building basic queries is easy, and is well documented.

528+

529+- However, the real interest of a tool like Squeal is in DRYness, and the documentation is still lacking in "how-to" related to composability.

530+

531+- I'll build an example showing how column selections and from clause can be factorized.

532+

533+- We want to write two queries:

534+

535+ * One to get all members of a specific group.

536+

537+ * One to get all the parliament.

538+

539+---

540+

541+# Decomposing a `Query`

542+

543+- A query typically stars with `select` (variants are available).

544+

545+- It then takes:

546+

547+ * A heterogenous list of fields with a scary signature;

548+

549+ * A virtual table (the from clause and filter clauses), called a `TableExpression`.

550+

551+- And return fields. Ours will look like this:

552+

553+```haskell

554+type GroupRowResult =

555+ '[ "groupName" ::: 'NotNull 'PGtext

556+ , "firstName" ::: 'NotNull 'PGtext

557+ , "lastName" ::: 'NotNull 'PGtext ]

558+```

559+

560+---

561+

562+# The Table Expression

563+

564+- It necessarily contains a `fromClause` (table, view or subquery, plus optional joins).

565+

566+- You can add where, groups, "HAVING" clause, order, etc.

567+

568+- `from` creates a basic `TableExpression` that you extend through various function to add clauses.

569+

570+- For our queries, we will share a common `FromClause`.

571+

572+---

573+

574+# The From Clause

575+

576+```

577+FromClause schema params from

578+```

579+

580+- We need Schema, input parameters and a `FromType` giving the available fields of the expression.

581+

582+- In our case, we'll join the table `mp` and the table `groupp`, meaning the `from` will be all fields of these tables.

583+

584+- We can use `TableToRow` to be more DRY:

585+

586+```haskell

587+type BaseParliamentSelection =

588+ '[ "g" ::: TableToRow GroupCols

589+ , "m" ::: TableToRow MpCols ]

590+```

591+

592+> _note_ We've also put everything with table aliases: "g" and "m".

593+

594+---

595+

596+# Writing our from clause

597+

598+```haskell

599+baseParliamentTables ::

600+ FromClause Schema (param :: [NullityType]) BaseParliamentSelection

601+baseParliamentTables =

602+ table

603+ (#groupp `as` #g)

604+ & innerJoin

605+ (table (#mp `as` #m))

606+ (#m ! #mp_group .== #g ! #groupp_id)

607+```

608+

609+- When picking "from" something, you need to specify the type with a function: `table` for a table, `view` for a view, etc.

610+

611+- All joins are available. `innerJoin` is the most basic one. It takes the joined table and the joining condition.

612+

613+- We have to specifiy the type of `param` (current limitation of the lib), even though _any_ params will be compatible with this, so we can plug `where` clauses depending on params should we need to !

614+

615+---

616+

617+# Typing the common selection

618+

619+- Both our querie will need the same fields. This has to be factorized too.

620+

621+- The scary signature of selection fields:

622+

623+```haskell

624+NP (Aliased (Expression schema from grouping params)) cols

625+```

626+

627+- `NP` is for heterogenous lists ("n-ary product").

628+

629+- `from` is the virtual table type, so our `BaseParliamentSelection`.

630+

631+- `grouping` is there to make a distinction between aggregated / unaggregated queries.

632+

633+- And finally, cols is the return type.

634+

635+---

636+

637+# Our common selection

638+

639+```haskell

640+groupSelection ::

641+ NP (Aliased (Expression Schema BaseParliamentSelection 'Ungrouped param))

642+ GroupRowResult

643+groupSelection =

644+ #g ! #name `as` #groupName

645+ :* #m ! #first_name `as` #firstName

646+ :* #m ! #last_name `as` #lastName

647+```

648+

649+- I hope you like big signatures.

650+

651+- But it's what let GHC checks that all alias and columns are available.

652+

653+- And that you're returning what you really intend to return.

654+

655+---

656+

657+# Putting it all together

658+

659+```haskell

660+selectParliament :: Query Schema '[] GroupRowResult

661+selectParliament =

662+ select groupSelection (from baseParliamentTables)

663+```

664+

665+```haskell

666+selectGroupMembers :: Query Schema '[ 'NotNull 'PGtext] GroupRowResult

667+selectGroupMembers =

668+ select groupSelection

669+ (from baseParliamentTables

670+ & where_ (#g ! #name .== param @1))

671+```

672+

673+- That is fairly DRY. And _entirely typesafe_.

674+

675+---

676+

677+# Actually fetching the data

678+

679+- We'll build an intermediary datatype representing our rows.

680+

681+- We'll make it match our row.

682+

683+- And we'll add generic-SOP so that we can build them from query results.

684+

685+```haskell

686+type GroupRowResult =

687+ '[ "groupName" ::: 'NotNull 'PGtext

688+ , "firstName" ::: 'NotNull 'PGtext

689+ , "lastName" ::: 'NotNull 'PGtext ]

690+```

691+

692+```haskell

693+data GroupRow =

694+ GroupRow { groupName :: Text

695+ , firstName :: Text

696+ , lastName :: Text }

697+ deriving (Generic)

698+

699+instance SOP.Generic GroupRow

700+instance SOP.HasDatatypeInfo GroupRow

701+```

702+

703+---

704+

705+# Aggregate result logic

706+

707+- We will get tabular, SQL data.

708+

709+- Our results will be `[GroupRow]`.

710+

711+- We'll build `Groups` from this:

712+

713+```haskell

714+buildGroup :: NE.NonEmpty GroupRow -> Group

715+buildGroup grs =

716+ let buildMP (GroupRow _ f l) = Mp f l

717+ name = groupName . NE.head $ grs

718+ members = NE.toList (buildMP <$> grs)

719+ in Group{..}

720+

721+rowToGroups :: [GroupRow] -> [Group]

722+rowToGroups =

723+ let grouped = fmap NE.fromList . L.groupBy ((==) `on` groupName)

724+ in fmap buildGroup . grouped

725+```

726+

727+---

728+

729+# Finally calling our queries

730+

731+- Query with params will use `runQueryParams`.

732+

733+- Query without params will use `runQuery`.

734+

735+- Result is inside a `MonadPQ` and of type `K` from generic-sop.

736+

737+- You get your actual result using `getRows`. Exemple:

738+

739+```haskell

740+getParliament :: (MonadPQ Schema m, MonadBaseControl IO m) => m [Group]

741+getParliament = do

742+ res <- runQuery selectParliament

743+ rows <- getRows res

744+ pure $ rowToGroups rows

745+```

746+

747+- In real life of course you'll write:

748+

749+```haskell

750+getParliament =

751+ rowToGroups <$> (runQuery selectParliament >>= getRows)

752+```

753+

754+---

755+

756+# Our query with params

757+

758+```haskell

759+getGroupMembers ::

760+ (MonadPQ Schema m, MonadBaseControl IO m) => Text -> m (Maybe Group)

761+getGroupMembers =

762+ listToMaybe . rowToGroups <$>

763+ (runQueryParams selectGroupMembers (Only t) >>= getRows)

764+```

765+

766+- And that's it.

767+

768+---

769+

770+![Eazy](https://media.tenor.com/images/8fc7c4077efe11b4a3a3b9ae4e643e87/tenor.gif)

771+

772+---

773+

774+# Conclusion

775+

776+---

777+

778+# Pros & Cons

779+

780+- Not everything is included: some cool stuff like array_agg and window functions are not available yet.

781+

782+- But development is _very_ active. `IN` clauses were missing but were added in the 4.0 released recently.

783+

784+- It's bleeding edge. You need latest LTS to be comfortable and psql >= 9.5.

785+

786+- It's Postgres-only but I would say that's a feature. Multi-DB tools are even more complex.

787+

788+- The author & maintainer is <3.

789+

790+- Typesafe. 'nuff said.

791+

792+---

793+

794+# Thank you !

stack.yaml+6−1

@@ -1,3 +1,8 @@

1−resolver: lts-11.1

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