7c8fe2d..dev · squeal · git.iko.soy

git.iko.soy/squeal

on dev help sign in

.circleci/config.ymlnew file+24

since splitsnapshots

unifiedsplit

@@ -0,0 +1,24 @@

1+version: 2

2+jobs:

3+ build:

4+ docker:

5+ - image: haskell:8.6.5

6+ - image: circleci/postgres:latest

7+ environment:

8+ POSTGRES_USER: root

9+ POSTGRES_DB: exampledb

10+ steps:

11+ - checkout

12+ - restore_cache:

13+ keys:

14+ - dependency-cache

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

16+ - run: stack upgrade && stack update

17+ - run: stack build --fast

18+ - run: stack test

19+ - run: stack haddock

20+ - save_cache:

21+ key: dependency-cache

22+ paths:

23+ - ".stack-work"

24+ - "/root/.stack/"

.gitignore+1

@@ -17,3 +17,4 @@ cabal.sandbox.config

17*.eventlog

18.stack-work/

19cabal.project.local

20+.DS_Store

README.md+275−2

@@ -2,6 +2,279 @@

3![squeal-icon](http://www.emoticonswallpapers.com/emotion/cute-big-pig/cute-pig-smiley-046.gif)

5−[![CircleCI](https://circleci.com/gh/echatav/squeal.svg?style=svg&circle-token=a699a654ef50db2c3744fb039cf2087c484d1226)](https://circleci.com/gh/echatav/squeal)

5+[![CircleCI](https://circleci.com/gh/echatav/squeal.svg?style=svg&circle-token=a699a654ef50db2c3744fb039cf2087c484d1226)](https://circleci.com/gh/morphismtech/squeal)

7−Main repository for the squeal database library.

7+[Github](https://github.com/morphismtech/squeal)

9+[Hackage](https://hackage.haskell.org/package/squeal-postgresql)

10+

11+[Stackage](https://www.stackage.org/package/squeal-postgresql)

12+

13+[YouTube](https://www.youtube.com/watch?v=rWfEQfAaNc4)

14+

15+## introduction

16+

17+Squeal is a deep embedding of SQL into Haskell. By "deep embedding", I am abusing the

18+term somewhat. What I mean is that Squeal embeds both SQL terms and SQL types

19+into Haskell at the term and type levels respectively. This leads to a very high level

20+of type-safety in Squeal.

21+

22+Squeal embeds not just the structured query language of SQL but also the

23+data manipulation language and the data definition language; that's `SELECT`,

24+`INSERT`, `UPDATE`, `DELETE`, `WITH`, `CREATE`, `DROP`, and `ALTER` commands.

25+

26+Squeal expressions closely match their corresponding SQL expressions so that

27+the SQL they actually generate is completely predictable. They are also highly

28+composable and cover a large portion of SQL.

29+

30+## features

31+

32+* generic encoding of Haskell tuples and records into query parameters

33+ and generic decoding of query results into Haskell records

34+ using [`generics-sop`](https://hackage.haskell.org/package/generics-sop)

35+* access to SQL alias system using the `OverloadedLabels` extension

36+* type-safe `NULL` and `DEFAULT`

37+* type-safe SQL constraints `CHECK`, `UNIQUE`, `PRIMARY KEY` and `FOREIGN KEY`

38+* type-safe aggregation

39+* escape hatches for writing raw SQL

40+* [`mtl`](https://hackage.haskell.org/package/mtl) compatible monad transformer

41+ for executing as well as preparing queries and manipulations

42+ and [Atkey](https://bentnib.org/paramnotions-jfp.pdf) indexed monad transformer

43+ for executing definitions.

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

54+

55+## installation

56+

57+`stack install squeal-postgresql`

58+

59+## testing

60+

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

62+

63+`stack test`

64+

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+

71+## usage

72+

73+Let's see an example!

74+

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

76+features.

77+

78+```Haskell

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

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

81+```

82+

83+We'll need some imports.

84+

85+```Haskell

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

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

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

89+>>> import Squeal.PostgreSQL

90+```

91+

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

93+

94+```Haskell

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

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

97+```

98+

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

100+we use `DataKinds` and `TypeOperators`.

101+

102+```Haskell

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"] ]

115+type Schema =

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

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

118+type Schemas = Public Schema

119+:}

120+```

121+

122+Notice the use of type operators.

123+

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+

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

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

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

131+

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

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

134+has two type parameters, corresponding to the schema

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

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

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

138+

139+```Haskell

140+>>> :{

141+let

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

143+ setup =

144+ createTable #users

145+ ( serial `as` #id :*

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

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

148+ createTable #emails

149+ ( serial `as` #id :*

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

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

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

153+ foreignKey #user_id #users #id

154+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

155+:}

156+```

157+

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

159+

160+```Haskell

161+>>> printSQL setup

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

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);

164+```

165+

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

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

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

169+`Definition` is simpler.

170+

171+```Haskell

172+>>> :{

173+let

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

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

176+:}

177+

178+>>> printSQL teardown

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

190+```

191+

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

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

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

195+and an output row. When

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

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

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

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

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

201+`with` statement.

202+

203+```Haskell

204+>>> :{

205+let

206+ insertUser :: Manipulation_ Schemas User ()

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

208+ where

209+ u = insertInto #users

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

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

212+ e = insertInto_ #emails $ Select

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

214+ (from (common #u))

215+:}

216+

217+>>> printSQL insertUser

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"

219+```

220+

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

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

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

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

225+

226+```Haskell

227+>>> :{

228+let

229+ getUsers :: Query_ Schemas () User

230+ getUsers = select_

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

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

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

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

235+:}

236+

237+>>> printSQL getUsers

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")

239+```

240+

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

242+

243+```Haskell

244+>>> :{

245+let

246+ users :: [User]

247+ users =

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

249+ , User "Bob" Nothing

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

251+ ]

252+:}

253+```

254+

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

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

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

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

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

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

261+`MonadPQ` functionality.

262+

263+```Haskell

264+>>> :{

265+let

266+ session :: PQ Schemas Schemas IO ()

267+ session = do

268+ _ <- traversePrepared_ insertUser users

269+ usersResult <- runQuery getUsers

270+ usersRows <- getRows usersResult

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

272+in

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

274+ define setup

275+ & pqThen session

276+ & pqThen (define teardown)

277+:}

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

279+-}

280+```

RELEASE NOTES.mdnew file+1217

@@ -0,0 +1,1217 @@

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+

1080+### Version 0.2.1 - April 7, 2018

1081+

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

1083+reserved words in PostgreSQL. To fix the issue, alias identifiers are now

1084+quoted. Thanks to Petter Rasmussen for the fix.

1085+

1086+### Version 0.2 - March 26, 2018

1087+

1088+**Changes**

1089+- **Constraints** - Type level table constraints like primary and foreign keys and column constraints like having `DEFAULT`.

1090+- **Migrations** - Support for linear, invertible migrations tracked in an auxiliary table

1091+- **Arrays** - Support for fixed- and variable-length arrays

1092+- **Aliases** - Generalized `Has` constraint

1093+- **Pools** - Support for pooled connections

1094+- **Transactions** - Support for transaction control language

1095+- **Queries, Manipulations, Definitions** - Small and large changes to Squeal's DSL

1096+

1097+Well, a lot of things changed!

1098+

1099+**Constraints**

1100+

1101+An important request was to bring constraints to the type level.

1102+This means that more of the schema is statically known. In `0.1` column constraints - which boil down

1103+to having `DEFAULT` or not - were at the type level, but they were confusingly named.

1104+

1105+```haskell

1106+0.1: 'Optional ('NotNull 'PGInt4)

1107+0.2: 'Def :=> 'NotNull 'PGInt4

1108+0.1: 'Required ('NotNull 'PGInt4)

1109+0.2: 'NoDef :=> 'NotNull 'PGInt4

1110+```

1111+

1112+The `:=>` type operator is intended to helpfully connote a constraint relation.

1113+It's also used for table constraints which are new in `0.2`.

1114+

1115+```haskell

1116+"emails" :::

1117+ '[ "pk_emails" ::: 'PrimaryKey '["id"]

1118+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]

1119+ ] :=>

1120+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4

1121+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4

1122+ , "email" ::: 'NoDef :=> 'Null 'PGtext

1123+ ]

1124+```

1125+

1126+Another change in the constraint system was the removal of column constraints from

1127+query and manipulation results, as result columns don't support a notion of `DEFAULT`.

1128+This necessitates a distinction between `TableType`s which have both column and table

1129+constraints and `RelationType`s which have neither.

1130+

1131+**Migrations**

1132+

1133+Migrations are a hot topic and many people have requested this feature. Squeal `0.2`

1134+adds support for linear, invertible migrations. That is, a migration is a named,

1135+invertible, schema-tracking computation:

1136+

1137+```haskell

1138+data Migration io schema0 schema1 = Migration

1139+ { name :: Text -- ^ The `name` of a `Migration`.

1140+ -- Each `name` in a `Migration` should be unique.

1141+ , up :: PQ schema0 schema1 io () -- ^ The `up` instruction of a `Migration`.

1142+ , down :: PQ schema1 schema0 io () -- ^ The `down` instruction of a `Migration`.

1143+ }

1144+```

1145+

1146+And, `Migration`s can be put together in an "aligned" list:

1147+

1148+```haskell

1149+data AlignedList p x0 x1 where

1150+ Done :: AlignedList p x x

1151+ (:>>) :: p x0 x1 -> AlignedList p x1 x2 -> AlignedList p x0 x2

1152+```

1153+

1154+These aligned lists are free categories and might look familiar from

1155+the [reflections without remorse](http://okmij.org/ftp/Haskell/zseq.pdf) technique,

1156+which uses their cousins, aligned sequences.

1157+

1158+In the context of migration, they allow one to chain new migrations as a

1159+schema evolves over time. `Migration`s' execution is tracked in an auxiliary

1160+migrations table. Migration lists can then be run or rewinded.

1161+

1162+```haskell

1163+migrateUp

1164+ :: MonadBaseControl IO io

1165+ => AlignedList (Migration io) schema0 schema1 -- ^ migrations to run

1166+ -> PQ

1167+ ("schema_migrations" ::: MigrationsTable ': schema0)

1168+ ("schema_migrations" ::: MigrationsTable ': schema1)

1169+ io ()

1170+

1171+migrateDown

1172+ :: MonadBaseControl IO io

1173+ => AlignedList (Migration io) schema0 schema1 -- ^ migrations to rewind

1174+ -> PQ

1175+ ("schema_migrations" ::: MigrationsTable ': schema1)

1176+ ("schema_migrations" ::: MigrationsTable ': schema0)

1177+ io ()

1178+```

1179+

1180+**Aliases**

1181+

1182+In Squeal `0.1`, we had different typeclasses `HasColumn` and `HasTable` to indicate

1183+that a table has a column or that a schema has a table. In Squeal `0.2` this has been

1184+unified to a single typeclass,

1185+

1186+```haskell

1187+class KnownSymbol alias =>

1188+ Has (alias :: Symbol) (fields :: [(Symbol,kind)]) (field :: kind)

1189+ | alias fields -> field where

1190+```

1191+

1192+**Arrays**

1193+

1194+Support for array types has been added to Squeal `0.2` through

1195+the `'PGfixarray` and `'PGvararray` `PGType`s. Array values can be

1196+constructed using the `array` function and can be encoded from and decoded to

1197+Haskell `Vector`s.

1198+

1199+**Pools**

1200+

1201+Squeal `0.2` provides a monad transformer `PoolPQ` that's an instance of `MonadPQ`.

1202+The `resource-pool` library is leveraged to provide striped pools of `Connection`s.

1203+`PoolPQ` should be a drop in replacement for running `Manipulation`s and `Query`s with

1204+`PQ`.

1205+

1206+**Transactions**

1207+

1208+Squeal `0.2` supports a simple transaction control language. A computation in

1209+`MonadPQ` can be called `transactionally` with different levels of isolation.

1210+Additionally, a schema changing computation, a data definition, can be run in a

1211+transaction. Running a computation in a transaction means that all SQL statements

1212+will be rolled back if an exception is encountered.

1213+

1214+**Queries, Manipulations and Definitions**

1215+

1216+The above changes required major and minor changes to Squeal DSL functions.

1217+Please consult the documentation.

circle.ymldeleted−10

@@ -1,10 +0,0 @@

1−dependencies:

2− cache_directories:

3− - "~/.stack"

4− - ".stack-work"

5− override:

6− - stack setup

7− - stack test --no-run-tests

8−test:

9− override:

10− - stack test

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/LICENSEnew file+31

@@ -0,0 +1,31 @@

5+Redistribution and use in source and binary forms, with or without

6+modification, are permitted provided that the following conditions are

7+met:

9+ * Redistributions of source code must retain the above copyright

10+ notice, this list of conditions and the following disclaimer.

11+

12+ * Redistributions in binary form must reproduce the above

13+ copyright notice, this list of conditions and the following

14+ disclaimer in the documentation and/or other materials provided

15+ with the distribution.

16+

17+ * Neither the names of the copyright holders nor the names of the

18+ contributors may be used to endorse or promote products derived

19+ from this software without specific prior written permission.

20+

21+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

22+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

23+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

24+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

25+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

26+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

27+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

28+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

29+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

30+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

31+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

squeal-postgresql/README.mdnew file+11

@@ -0,0 +1,11 @@

1+# squeal-postgresql

3+![squeal-icon](http://www.emoticonswallpapers.com/emotion/cute-big-pig/cute-pig-smiley-046.gif)

5+[![CircleCI](https://circleci.com/gh/echatav/squeal.svg?style=svg&circle-token=a699a654ef50db2c3744fb039cf2087c484d1226)](https://circleci.com/gh/morphismtech/squeal)

7+[Github](https://github.com/morphismtech/squeal)

9+[Hackage](https://hackage.haskell.org/package/squeal-postgresql)

10+

11+[Stackage](https://www.stackage.org/package/squeal-postgresql)

squeal-postgresql/docs-upload.shnew file+18

@@ -0,0 +1,18 @@

1+#!/bin/bash

3+# Run this script in the top-level of your package directory

4+# (where the .cabal file is) to compile documentation and

5+# upload it to hackage.

7+# Requirements:

8+# cabal-install-1.24 (for --for-hackage)

9+# haddock 2.17 (for the hyperlinked source)

10+

11+set -e

12+

13+dir=$(mktemp -d dist-docs.XXXXXX)

14+trap 'rm -r "$dir"' EXIT

15+

16+cabal configure --builddir="$dir"

17+cabal haddock --builddir="$dir" --for-hackage --haddock-option=--hyperlinked-source

18+cabal upload -d $dir/*-docs.tar.gz

squeal-postgresql/exe/Example.hs+96−58

@@ -1,40 +1,107 @@

1{-# LANGUAGE

2 DataKinds

3 , DeriveGeneric

4− , FlexibleInstances

4+ , FlexibleContexts

5− , MultiParamTypeClasses

6 , OverloadedLabels

5 , OverloadedLabels

7 , OverloadedStrings

6 , OverloadedStrings

7+ , OverloadedLists

8 , TypeApplications

9 , TypeOperators

10− , TypeSynonymInstances

11#-}

10#-}

13−module Main (main,col1,col2) where

12+module Main (main, main2) where

13+

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

15+import Data.Int (Int16, Int32)

16+import Data.Monoid ((<>))

17+import Data.Text (Text)

18+import Data.Vector (Vector)

15−import Control.Category ((>>>))

16−import Control.Monad.Base

17−import Data.Function ((&))

18−import Data.Int

19−import Data.Monoid

20−import Generics.SOP hiding (from)

21import Squeal.PostgreSQL

20import Squeal.PostgreSQL

23import qualified Data.ByteString.Char8 as Char8

22import qualified Data.ByteString.Char8 as Char8

23+import qualified Generics.SOP as SOP

24import qualified GHC.Generics as GHC

26type Schema =

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

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

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

27− '[ "students" ::: '["name" ::: 'Required ('NotNull 'PGtext)]

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

28− , "table1" :::

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

32+ ])

33+ , "emails" ::: 'Table (

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

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

36+ ] :=>

29− '[ "col1" ::: 'Required ('NotNull 'PGint4)

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

30− , "col2" ::: 'Required ('NotNull 'PGint4)

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

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

31− ]

40+ ])

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

32 ]

42 ]

34−data Table1Row = Table1Row { col1 :: Int32, col2 :: Int32 }

44+type Schemas = Public Schema

45+

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

47+setup =

48+ createTable #users

49+ ( serial `as` #id :*

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

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

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

53+ >>>

54+ createTable #emails

55+ ( serial `as` #id :*

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

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

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

59+ foreignKey #user_id #users #id

60+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

61+ >>>

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

63+

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

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

66+

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

68+insertUser = insertInto #users

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

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

71+

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

73+insertEmail = insertInto_ #emails

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

75+

76+getUsers :: Query_ Schemas () User

77+getUsers = select_

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

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

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

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

82+

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

35 deriving (Show, GHC.Generic)

84 deriving (Show, GHC.Generic)

36−instance Generic Table1Row

85+instance SOP.Generic User

37−instance HasDatatypeInfo Table1Row

86+instance SOP.HasDatatypeInfo User

87+

88+users :: [User]

89+users =

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

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

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

93+ ]

94+

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

96+session = do

97+ liftIO $ Char8.putStrLn "manipulating"

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

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

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

101+ liftIO $ Char8.putStrLn "querying"

102+ usersResult <- runQuery getUsers

103+ usersRows <- getRows usersResult

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

105

39main :: IO ()

106main :: IO ()

40main = do

107main = do

@@ -44,44 +111,15 @@ main = do

44 Char8.putStrLn $ "connecting to " <> connectionString

111 Char8.putStrLn $ "connecting to " <> connectionString

45 connection0 <- connectdb connectionString

112 connection0 <- connectdb connectionString

46 Char8.putStrLn "setting up schema"

113 Char8.putStrLn "setting up schema"

47− connection1 <- runPQ (connection0 :: Connection '[]) $ pqExec $

114+ connection1 <- execPQ (define setup) connection0

48− createTable #students ((text & notNull) `As` #name :* Nil ) []

115+ connection2 <- execPQ session connection1

49− >>>

50− createTable #table1

51− ((int4 & notNull) `As` #col1 :* (int4 & notNull) `As` #col2 :* Nil) []

52− connection2 <- runPQ (connection1 :: Connection Schema) $ do

53− let

54− manipulation :: Manipulation Schema

55− '[ 'Required ('NotNull 'PGint4)

56− , 'Required ('NotNull 'PGint4)

57− , 'Required ('NotNull 'PGint4)

58− , 'Required ('NotNull 'PGint4)

59− ] '[]

60− manipulation =

61− insertInto #table1

62− ( Values

63− (param (Proxy @1) `As` #col1 :* param (Proxy @2) `As` #col2 :* Nil)

64− [param (Proxy @3) `As` #col1 :* param (Proxy @4) `As` #col2 :* Nil]

65− ) Conflict (Returning Nil)

66− liftBase $ Char8.putStrLn "manipulating"

67− _ <- pqExecParams manipulation (1::Int32,2::Int32,3::Int32,4::Int32)

68− liftBase $ Char8.putStrLn "querying"

69− Just result <- pqExecNil . query $

70− selectStar (from (Table (#table1 `As` #table1)))

71− value00 <- getValue (RowNumber 0) (columnNumber @0) result

72− value01 <- getValue (RowNumber 0) (columnNumber @1) result

73− value10 <- getValue (RowNumber 1) (columnNumber @0) result

74− value11 <- getValue (RowNumber 1) (columnNumber @1) result

75− row0 <- getRow (RowNumber 0) result

76− row1 <- getRow (RowNumber 1) result

77− liftBase $ do

78− print (value00 :: Int32)

79− print (value01 :: Int32)

80− print (value10 :: Int32)

81− print (value11 :: Int32)

82− print (row0 :: Table1Row)

83− print (row1 :: Table1Row)

84 Char8.putStrLn "tearing down schema"

116 Char8.putStrLn "tearing down schema"

85− connection3 <- runPQ (connection2 :: Connection Schema) $ pqExec $

117+ connection3 <- execPQ (define teardown) connection2

86− dropTable #table1 >>> dropTable #students

87− finish (connection3 :: Connection '[])

118+ finish connection3

119+

120+main2 :: IO ()

121+main2 =

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

123+ define setup

124+ & pqThen session

125+ & pqThen (define teardown)

squeal-postgresql/squeal-postgresql.cabal+118−42

@@ -1,71 +1,147 @@

1name: squeal-postgresql

2−version: 0.0.0.1

2+version: 0.5.1.0

3synopsis: Squeal PostgreSQL Library

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

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

5−homepage: https://github.com/echatav/squeal

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

6+bug-reports: https://github.com/morphismtech/squeal/issues

7+license: BSD3

8+license-file: LICENSE

6author: Eitan Chatav

9author: Eitan Chatav

7maintainer: eitan.chatav@gmail.com

10maintainer: eitan.chatav@gmail.com

8−copyright: 2017 Morphism, LLC

9category: Database

12category: Database

10build-type: Simple

13build-type: Simple

11−cabal-version: >=1.10

14+cabal-version: >=1.18

15+extra-doc-files: README.md

16+

17+source-repository head

18+ type: git

19+ location: https://github.com/morphismtech/squeal.git

13library

21library

14 hs-source-dirs: src

22 hs-source-dirs: src

15 exposed-modules:

23 exposed-modules:

16 Squeal.PostgreSQL

24 Squeal.PostgreSQL

25+ Squeal.PostgreSQL.Alias

17 Squeal.PostgreSQL.Binary

26 Squeal.PostgreSQL.Binary

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

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

55+ Squeal.PostgreSQL.Manipulation

56+ Squeal.PostgreSQL.Migration

57+ Squeal.PostgreSQL.Pool

58+ Squeal.PostgreSQL.PG

18 Squeal.PostgreSQL.PQ

59 Squeal.PostgreSQL.PQ

19− Squeal.PostgreSQL.Statement

60+ Squeal.PostgreSQL.Render

61+ Squeal.PostgreSQL.Query

20 Squeal.PostgreSQL.Schema

62 Squeal.PostgreSQL.Schema

63+ Squeal.PostgreSQL.Transaction

64+ default-language: Haskell2010

65+ ghc-options: -Wall

66+ build-depends:

67+ aeson >= 1.2.4.0

68+ , base >= 4.11.1.0 && < 5.0

69+ , binary-parser >= 0.5.5

70+ , bytestring >= 0.10.8.2

71+ , bytestring-strict-builder >= 0.4.5

72+ , deepseq >= 1.4.3.0

73+ , free-categories >= 0.1.0.0

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

75+ , mmorph >= 1.1.1

76+ , mtl >= 2.2.2

77+ , network-ip >= 0.3.0.2

78+ , postgresql-binary >= 0.12.1

79+ , postgresql-libpq >= 0.9.4.1

80+ , records-sop >= 0.1.0.0

81+ , resource-pool >= 0.2.3.2

82+ , scientific >= 0.3.5.3

83+ , text >= 1.2.3.0

84+ , time >= 1.8.0.2

85+ , transformers >= 0.5.2.0

86+ , unliftio >= 0.2.10

87+ , unliftio-pool >= 0.2.1.0

88+ , uuid-types >= 1.0.3

89+ , vector >= 0.12.0.1

90+

91+test-suite doctest

92+ default-language: Haskell2010

93+ type: exitcode-stdio-1.0

94+ hs-source-dirs: test

95+ ghc-options: -Wall

96+ main-is: Doc.hs

97+ build-depends:

98+ base >= 4.10.0.0

99+ , doctest >= 0.11.4

100+ , squeal-postgresql

101+

102+test-suite properties

21 default-language: Haskell2010

103 default-language: Haskell2010

104+ type: exitcode-stdio-1.0

105+ hs-source-dirs: test

22− ghc-options: -Wall -Werror -fprint-explicit-kinds

106+ ghc-options: -Wall

107+ main-is: Property.hs

23 build-depends:

108 build-depends:

24− aeson

109+ base >= 4.10.0.0

25− , base

26− , bytestring

110+ , bytestring >= 0.10.8.2

27− , generics-sop

111+ , hedgehog >= 1.0

28− , lifted-base

29− , monad-control

30− , mtl

112+ , mtl >= 2.2.2

31− , network-ip

32− , postgresql-binary

33− , postgresql-libpq

34− , scientific

113+ , scientific >= 0.3.5.3

35− , text

114+ , squeal-postgresql

36− , time

115+ , time >= 1.8.0.2

37− , transformers

38− , transformers-base

39− , uuid

116

41−test-suite squeal-postgresql-test

117+test-suite spec

42 default-language: Haskell2010

118 default-language: Haskell2010

43 type: exitcode-stdio-1.0

119 type: exitcode-stdio-1.0

44 hs-source-dirs: test

120 hs-source-dirs: test

45− ghc-options: -Wall -Werror

121+ ghc-options: -Wall

46 main-is: Spec.hs

122 main-is: Spec.hs

47− other-modules:

48− Squeal.PostgreSQL.StatementSpec

49 build-depends:

123 build-depends:

50− base

124+ base >= 4.10.0.0

125+ , async >= 2.2.2

126+ , bytestring >= 0.10.8.2

51− , generics-sop

127+ , generics-sop >= 0.3.1.0

52− , hspec

128+ , hspec >= 2.4.8

129+ , mtl >= 2.2.2

53 , squeal-postgresql

130 , squeal-postgresql

131+ , text >= 1.2.2.2

132+ , vector >= 0.12.0.1

133

55−executable squeal-postgresql-example

134+executable example

56 default-language: Haskell2010

135 default-language: Haskell2010

57 hs-source-dirs: exe

136 hs-source-dirs: exe

58− ghc-options: -Wall -Werror

137+ ghc-options: -Wall

59 main-is: Example.hs

138 main-is: Example.hs

60 build-depends:

139 build-depends:

61− base

140+ base >= 4.10.0.0 && < 5.0

62− , bytestring

141+ , bytestring >= 0.10.8.2

63− , generics-sop

142+ , generics-sop >= 0.3.1.0

64− , mtl

143+ , mtl >= 2.2.1

65 , squeal-postgresql

144 , squeal-postgresql

66− , transformers

145+ , text >= 1.2.2.2

67− , transformers-base

146+ , transformers >= 0.5.2.0

68−

147+ , vector >= 0.12.0.1

69−source-repository head

70− type: git

71− location: https://github.com/echatav/squeal

squeal-postgresql/src/Squeal/PostgreSQL.hs+233−11

@@ -1,11 +1,233 @@

1+{-|

2+Module: Squeal.PostgreSQL

3+Description: Squeal export module

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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

9+Let's see an example!

10+

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

12+features.

13+

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

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

16+

17+We'll need some imports.

18+

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

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

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

22+>>> import Squeal.PostgreSQL

23+

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

25+

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

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

28+

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

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

31+

32+>>> :{

33+type UsersColumns =

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

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

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

37+type EmailsColumns =

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

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

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

41+type EmailsConstraints =

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

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

44+type Schema =

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

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

47+type Schemas = Public Schema

48+:}

49+

50+Notice the use of type operators.

51+

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+

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

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

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

59+

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

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

62+has two type parameters, corresponding to the schema

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

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

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

66+

67+>>> :{

68+let

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

70+ setup =

71+ createTable #users

72+ ( serial `as` #id :*

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

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

75+ createTable #emails

76+ ( serial `as` #id :*

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

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

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

80+ foreignKey #user_id #users #id

81+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

82+:}

83+

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

85+

86+>>> printSQL setup

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

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);

89+

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

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

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

93+`Definition` is simpler.

94+

95+>>> :{

96+let

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

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

99+:}

100+

101+>>> printSQL teardown

102+DROP TABLE "emails";

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+

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

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

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

115+and an output row. When

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

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

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

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

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

121+`with` statement.

122+

123+>>> :{

124+let

125+ insertUser :: Manipulation_ Schemas User ()

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

127+ where

128+ u = insertInto #users

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

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

131+ e = insertInto_ #emails $ Select

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

133+ (from (common #u))

134+:}

135+

136+>>> printSQL insertUser

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

138+

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

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

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

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

143+

144+>>> :{

145+let

146+ getUsers :: Query_ Schemas () User

147+ getUsers = select_

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

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

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

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

152+:}

153+

154+>>> printSQL getUsers

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")

156+

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

158+

159+>>> :{

160+let

161+ users :: [User]

162+ users =

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

164+ , User "Bob" Nothing

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

166+ ]

167+:}

168+

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

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

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

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

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

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

175+`MonadPQ` functionality.

176+

177+>>> :{

178+let

179+ session :: PQ Schemas Schemas IO ()

180+ session = do

181+ _ <- traversePrepared_ insertUser users

182+ usersResult <- runQuery getUsers

183+ usersRows <- getRows usersResult

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

185+in

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

187+ define setup

188+ & pqThen session

189+ & pqThen (define teardown)

190+:}

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

192+-}

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

194+

195+import Squeal.PostgreSQL.Alias as X

196+import Squeal.PostgreSQL.Binary as X

197+import Squeal.PostgreSQL.Definition as X

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

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

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

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

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

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

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

205+import Squeal.PostgreSQL.Expression as X

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

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

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

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

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

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

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

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

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

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

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

1−module Squeal.PostgreSQL

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

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

2− ( module Squeal.PostgreSQL.Binary

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

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

3− , module Squeal.PostgreSQL.PQ

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

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

4− , module Squeal.PostgreSQL.Schema

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

224+import Squeal.PostgreSQL.List as X

5− , module Squeal.PostgreSQL.Statement

225+import Squeal.PostgreSQL.Manipulation as X

6− ) where

226+import Squeal.PostgreSQL.Migration as X

7−

227+import Squeal.PostgreSQL.PG as X

8−import Squeal.PostgreSQL.Binary

228+import Squeal.PostgreSQL.Pool as X

9−import Squeal.PostgreSQL.PQ

229+import Squeal.PostgreSQL.PQ as X

230+import Squeal.PostgreSQL.Query as X

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

10−import Squeal.PostgreSQL.Schema

232+import Squeal.PostgreSQL.Schema as X

11−import Squeal.PostgreSQL.Statement

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+774−104

@@ -1,62 +1,296 @@

1+{-|

2+Module: Squeal.PostgreSQL.Binary

3+Description: Binary encoding and decoding

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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

179+-}

180+

1{-# LANGUAGE

181{-# LANGUAGE

2− DataKinds

182+ AllowAmbiguousTypes

3− , DefaultSignatures

4 , DeriveFoldable

183 , DeriveFoldable

5 , DeriveFunctor

184 , DeriveFunctor

6 , DeriveGeneric

185 , DeriveGeneric

7 , DeriveTraversable

186 , DeriveTraversable

187+ , DefaultSignatures

8 , FlexibleContexts

188 , FlexibleContexts

9 , FlexibleInstances

189 , FlexibleInstances

190+ , FunctionalDependencies

10 , GADTs

191 , GADTs

11 , LambdaCase

192 , LambdaCase

12− , KindSignatures

193+ , OverloadedStrings

13 , MultiParamTypeClasses

194 , MultiParamTypeClasses

14 , ScopedTypeVariables

195 , ScopedTypeVariables

15 , TypeApplications

196 , TypeApplications

16 , TypeFamilies

197 , TypeFamilies

198+ , TypeInType

17 , TypeOperators

199 , TypeOperators

18 , UndecidableInstances

200 , UndecidableInstances

201+ , UndecidableSuperClasses

19#-}

202#-}

203

21−module Squeal.PostgreSQL.Binary where

204+module Squeal.PostgreSQL.Binary

205+ ( -- * Encoding

206+ ToParam (..)

207+ , ToParams (..)

208+ , ToNullityParam (..)

209+ , ToField (..)

210+ , ToFixArray (..)

211+ -- * Decoding

212+ , FromValue (..)

213+ , FromRow (..)

214+ , FromField (..)

215+ , FromFixArray (..)

216+ -- * Only

217+ , Only (..)

218+ -- * Oid

219+ , OidOf (..)

220+ , OidOfParam (..)

221+ , OidOfField (..)

222+ ) where

223

23−import Data.Aeson hiding (Null)

224+import BinaryParser

24−import Data.Bits

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

226+import Control.Arrow (left)

227+import Control.Monad

25import Data.Int

228import Data.Int

229+import Data.Kind

26import Data.Scientific

230import Data.Scientific

27import Data.Time

231import Data.Time

232+import Data.UUID.Types

233+import Data.Vector (Vector)

28import Data.Word

234import Data.Word

29−import Data.UUID

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

30import Generics.SOP

236import Generics.SOP

237+import Generics.SOP.Record

238+import GHC.TypeLits

31import Network.IP.Addr

239import Network.IP.Addr

240

33−import qualified Data.ByteString.Lazy as Lazy

241+import qualified Data.Aeson as Aeson

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

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

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

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

35−import qualified Data.Text.Lazy as Lazy

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

36−import qualified Data.Text as Strict

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

37−import qualified Generics.SOP.Type.Metadata as Type

247+import qualified Data.Text as Strict.Text

248+import qualified Data.Vector as Vector

249+import qualified Database.PostgreSQL.LibPQ as LibPQ

38import qualified GHC.Generics as GHC

250import qualified GHC.Generics as GHC

39import qualified PostgreSQL.Binary.Decoding as Decoding

251import qualified PostgreSQL.Binary.Decoding as Decoding

40import 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

42import Squeal.PostgreSQL.Schema

257import Squeal.PostgreSQL.Schema

258

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

260+-- into the binary format of a PostgreSQL `PGType`.

261+class ToParam (x :: Type) (pg :: PGType) where

262+ -- | >>> :set -XTypeApplications -XDataKinds

263+ -- >>> toParam @Bool @'PGbool False

264+ -- K "\NUL"

265+ --

266+ -- >>> toParam @Int16 @'PGint2 0

267+ -- K "\NUL\NUL"

268+ --

269+ -- >>> toParam @Int32 @'PGint4 0

270+ -- K "\NUL\NUL\NUL\NUL"

271+ --

272+ -- >>> :set -XMultiParamTypeClasses

273+ -- >>> newtype Id = Id { getId :: Int16 } deriving Show

274+ -- >>> instance ToParam Id 'PGint2 where toParam = toParam . getId

275+ -- >>> toParam @Id @'PGint2 (Id 1)

276+ -- K "\NUL\SOH"

44−class ToParam x (pg :: PGType) where toParam :: x -> K Encoding.Encoding pg

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

45instance ToParam Bool 'PGbool where toParam = K . Encoding.bool

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

46instance ToParam Int16 'PGint2 where toParam = K . Encoding.int2_int16

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

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

48instance ToParam Int32 'PGint4 where toParam = K . Encoding.int4_int32

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

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

50instance ToParam Int64 'PGint8 where toParam = K . Encoding.int8_int64

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

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

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

52instance ToParam Float 'PGfloat4 where toParam = K . Encoding.float4

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

53instance ToParam Double 'PGfloat8 where toParam = K . Encoding.float8

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

54instance 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

55instance ToParam UUID 'PGuuid where toParam = K . Encoding.uuid

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

56instance ToParam (NetAddr IP) 'PGinet where toParam = K . Encoding.inet

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

57instance ToParam Char ('PGchar 1) where toParam = K . Encoding.char_utf8

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

58instance ToParam Strict.Text 'PGtext where toParam = K . Encoding.text_strict

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

59instance 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

60instance ToParam Strict.ByteString 'PGbytea where

294instance ToParam Strict.ByteString 'PGbytea where

61 toParam = K . Encoding.bytea_strict

295 toParam = K . Encoding.bytea_strict

62instance ToParam Lazy.ByteString 'PGbytea where

296instance ToParam Lazy.ByteString 'PGbytea where

@@ -70,109 +304,545 @@ instance ToParam LocalTime 'PGtimestamp where

70instance ToParam UTCTime 'PGtimestamptz where

304instance ToParam UTCTime 'PGtimestamptz where

71 toParam = K . Encoding.timestamptz_int

305 toParam = K . Encoding.timestamptz_int

72instance ToParam DiffTime 'PGinterval where toParam = K . Encoding.interval_int

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

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

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

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

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

75−

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

76−class ToColumnParam x (ty :: ColumnType) where

310+ toParam = K . Encoding.json_bytes

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

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

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

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

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

313+ toParam = K . Encoding.jsonb_bytes

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

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

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

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

82−instance ToParam x pg => ToColumnParam (Maybe x) ('Optional (nullity pg)) where

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

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

317+ toParam = K

84−

318+ . Encoding.array_foldable

85−class SListI tys => ToParams x (tys :: [ColumnType]) where

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

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

320+ . getVarArray

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

321+instance (ToParam x pg, OidOf pg)

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

323+ toParam = K

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

325+ . getVarArray

326+instance (ToParam x pg, OidOf pg)

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

328+ toParam = K

329+ . Encoding.nullableArray_vector

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

331+ . getVarArray

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

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

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

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

336+instance

337+ ( IsEnumType x

338+ , HasDatatypeInfo x

339+ , LabelsPG x ~ labels

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

341+ toParam =

342+ let

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

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

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

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

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

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

526+

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

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

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

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

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

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

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

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

535+

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

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

538+-- You should not define instances for

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

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

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

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

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

544+ . toNullityParam @x @ty

545+instance

546+ ( IsProductType product xs

547+ , Length xs ~ dim

548+ , All ((~) x) xs

549+ , ToFixArray x dims ty )

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

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

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

553+

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

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

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

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

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

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

560+ -- >>> toParams @(Bool, Maybe Int16) @'[ 'NotNull 'PGbool, 'Null 'PGint2] (False, Just 0)

561+ -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil

562+ --

563+ -- >>> :set -XDeriveGeneric

564+ -- >>> data Tuple = Tuple { p1 :: Bool, p2 :: Maybe Int16} deriving GHC.Generic

565+ -- >>> instance Generic Tuple

566+ -- >>> toParams @Tuple @Params (Tuple False (Just 0))

567+ -- K (Just "\NUL") :* K (Just "\NUL\NUL") :* Nil

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

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

88 => ToParams x tys where

570 => ToParams x tys where

89 toParams

571 toParams

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

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

91 . unZ . unSOP . from

573 . unZ . unSOP . from

574

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

576+-- a PostgreSQL `PGType` into a Haskell `Type`.

93−class FromValue (pg :: PGType) y where

577+class FromValue (pg :: PGType) (y :: Type) where

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

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

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

580+ fromValue :: Decoding.Value y

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

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

96−instance (Integral int, Bits int) => FromValue 'PGint2 int where

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

97− fromValue _ = Decoding.int

98−instance (Integral int, Bits int) => FromValue 'PGint4 int where

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

99− fromValue _ = Decoding.int

100−instance (Integral int, Bits int) => FromValue 'PGint8 int where

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

101− fromValue _ = Decoding.int

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

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

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

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

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

104−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

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

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

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

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

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

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

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

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

109−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

110instance FromValue 'PGbytea Strict.ByteString where

597instance FromValue 'PGbytea Strict.ByteString where

111− fromValue _ = Decoding.bytea_strict

598+ fromValue = Decoding.bytea_strict

112instance FromValue 'PGbytea Lazy.ByteString where

599instance FromValue 'PGbytea Lazy.ByteString where

113− fromValue _ = Decoding.bytea_lazy

600+ fromValue = Decoding.bytea_lazy

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

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

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

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

116instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where

603instance FromValue 'PGtimetz (TimeOfDay, TimeZone) where

117− fromValue _ = Decoding.timetz_int

604+ fromValue = Decoding.timetz_int

118instance FromValue 'PGtimestamp LocalTime where

605instance FromValue 'PGtimestamp LocalTime where

119− fromValue _ = Decoding.timestamp_int

606+ fromValue = Decoding.timestamp_int

120instance FromValue 'PGtimestamptz UTCTime where

607instance FromValue 'PGtimestamptz UTCTime where

121− fromValue _ = Decoding.timestamptz_int

608+ fromValue = Decoding.timestamptz_int

122instance FromValue 'PGinterval DiffTime where

609instance FromValue 'PGinterval DiffTime where

123− fromValue _ = Decoding.interval_int

610+ fromValue = Decoding.interval_int

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

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

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

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

126−

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

127−class FromColumnValue (colty :: (Symbol,ColumnType)) y where

614+ fromValue = Json <$>

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

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

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

617+ fromValue = Jsonb <$>

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

619+instance FromValue pg y

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

621+ fromValue =

622+ let

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

624+ in

625+ Decoding.array $ Decoding.dimensionArray rep

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

129instance FromValue pg y

627instance FromValue pg y

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

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

131− fromColumnValue = \case

629+ fromValue =

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

133− K (Just bytes) ->

134− let

630+ let

135− errOrValue =

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

136− Decoding.valueParser (fromValue @pg @y Proxy) bytes

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

138− in

632+ in

139− either err id errOrValue

633+ Decoding.array $ Decoding.dimensionArray rep

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

140instance FromValue pg y

635instance FromValue pg y

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

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

142− fromColumnValue (K nullOrBytes)

637+ fromValue =

143− = either err id

638+ let

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

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

145− <$> nullOrBytes

640+ in

146− where

641+ Decoding.array $ Decoding.dimensionArray rep

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

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

148−

643+instance FromValue pg y

149−class SListI columns => FromRow (columns :: [(Symbol,ColumnType)]) y where

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

150− fromRow :: NP (K (Maybe Strict.ByteString)) columns -> y

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)

151instance

654instance

152− ( SListI columns, IsProductType y ys

655+ ( IsEnumType y

153− , AllZip FromColumnValue columns ys

154 , HasDatatypeInfo y

656 , HasDatatypeInfo y

155− , SameFields (DatatypeInfoOf y) columns

657+ , LabelsPG y ~ labels

156− ) => FromRow columns y where

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

659+ fromValue =

660+ let

661+ greadConstructor

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+

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

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

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

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

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

708+ fromField

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

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

711+instance FromValue pg y

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

713+ fromField = Comp . \case

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

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

716+ Decoding.valueParser (fromValue @pg) bytestring

717+instance FromValue pg y

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

719+ fromField = Comp . \case

720+ K Nothing -> Right $ P Nothing

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

722+ Decoding.valueParser (fromValue @pg) bytestring

723+

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

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

726+-- You should not define instances for

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

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

729+ fromFixArray :: Decoding.Array y

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

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

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

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

734+instance

735+ ( IsProductType product ys

736+ , Length ys ~ dim

737+ , All ((~) y) ys

738+ , FromFixArray dims ty y )

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

740+ fromFixArray =

741+ let

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

743+ in

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

745+

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

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

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

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

750+-- provide `FromRow` instances.

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

752+ -- | >>> :set -XOverloadedStrings

753+ -- >>> import Data.Text

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

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

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

757+ -- >>> instance Generic UserRow

758+ -- >>> instance HasDatatypeInfo UserRow

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

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

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

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

763+instance

764+ ( SListI result

765+ , IsRecord y ys

766+ , AllZip FromField result ys

767+ ) => FromRow result y where

157 fromRow

768 fromRow

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

769+ = fmap fromRecord

159−

770+ . hsequence'

160−class SameField

771+ . htrans (Proxy @FromField) fromField

161− (fieldInfo :: Type.FieldInfo) (columnty :: (Symbol,ColumnType)) where

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

162−instance field ~ column => SameField ('Type.FieldInfo field) (column ::: ty)

773+-- P records

163−

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

164−type family SameFields

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

165− (datatypeInfo :: Type.DatatypeInfo) (columns :: [(Symbol,ColumnType)]) where

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

166− SameFields

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

167− ('Type.ADT _module _datatype '[ 'Type.Record _constructor fields])

778+-- instance

168− columns

779+-- ( row ~ Join row1 row2

169− = AllZip SameField fields columns

780+-- , FromRow row1 hask1

170− SameFields

781+-- , FromRow row2 hask2

171− ('Type.Newtype _module _datatype ('Type.Record _constructor '[field]))

782+-- , SListI row

172− '[column]

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

173− = SameField field column

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

174−

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)

819+

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

821+-- `toParams` or decoding a single value with `fromRow`.

822+--

823+-- >>> import Data.Text

824+-- >>> toParams @(Only (Maybe Text)) @'[ 'Null 'PGtext] (Only (Just "foo"))

825+-- K (Just "foo") :* Nil

826+--

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

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

175−newtype Only x = Only { only :: x }

829+newtype Only x = Only { fromOnly :: x }

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

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

177instance Generic (Only x)

831instance Generic (Only x)

178instance 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.hsnew file+82

@@ -0,0 +1,82 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition

3+Description: Squeal data definition language

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Squeal data definition language.

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+ , UndecidableInstances

31+#-}

32+

33+module Squeal.PostgreSQL.Definition

34+ ( -- * Definition

35+ Definition (..)

36+ , (>>>)

37+ , manipDefinition

38+ ) where

39+

40+import Control.Category

41+import Control.DeepSeq

42+import Data.ByteString

43+import Data.Monoid

44+import Prelude hiding ((.), id)

45+

46+import qualified GHC.Generics as GHC

47+

48+import Squeal.PostgreSQL.Manipulation

49+import Squeal.PostgreSQL.Render

50+import Squeal.PostgreSQL.Schema

51+

52+-- $setup

53+-- >>> import Squeal.PostgreSQL

54+

55+{-----------------------------------------

56+statements

57+-----------------------------------------}

58+

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

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

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

62+newtype Definition

63+ (schemas0 :: SchemasType)

64+ (schemas1 :: SchemasType)

65+ = UnsafeDefinition { renderDefinition :: ByteString }

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

67+

68+instance RenderSQL (Definition schemas0 schemas1) where

69+ renderSQL = renderDefinition

70+

71+instance Category Definition where

72+ id = UnsafeDefinition ";"

73+ ddl1 . ddl0 = UnsafeDefinition $

74+ renderSQL ddl0 <> "\n" <> renderSQL ddl1

75+

76+-- | A `Manipulation` without input or output can be run as a statement

77+-- along with other `Definition`s, by embedding it using `manipDefinition`.

78+manipDefinition

79+ :: Manipulation '[] schemas '[] '[]

80+ -- ^ no input or output

81+ -> Definition schemas schemas

82+manipDefinition = UnsafeDefinition . (<> ";") . renderSQL

squeal-postgresql/src/Squeal/PostgreSQL/Definition/Function.hsnew file+238

@@ -0,0 +1,238 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.Function

3+Description: Create and drop function and operator definitions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Create and drop function and operator definitions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DerivingStrategies

17+ , FlexibleContexts

18+ , FlexibleInstances

19+ , GADTs

20+ , LambdaCase

21+ , MultiParamTypeClasses

22+ , OverloadedLabels

23+ , OverloadedStrings

24+ , RankNTypes

25+ , ScopedTypeVariables

26+ , TypeApplications

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableSuperClasses

30+#-}

31+

32+module Squeal.PostgreSQL.Definition.Function

33+ ( createFunction

34+ , createOrReplaceFunction

35+ , createSetFunction

36+ , createOrReplaceSetFunction

37+ , createBinaryOp

38+ , createLeftOp

39+ , createRightOp

40+ , dropFunction

41+ , dropFunctionIfExists

42+ , dropOperator

43+ , dropOperatorIfExists

44+ , FunctionDefinition(..)

45+ , languageSqlExpr

46+ , languageSqlQuery

47+ ) where

48+

49+import Control.DeepSeq

50+import Data.ByteString

51+import GHC.TypeLits

52+

53+import qualified Generics.SOP as SOP

54+import qualified GHC.Generics as GHC

55+

56+import Squeal.PostgreSQL.Alias

57+import Squeal.PostgreSQL.Definition

58+import Squeal.PostgreSQL.Expression

59+import Squeal.PostgreSQL.Expression.Type

60+import Squeal.PostgreSQL.List

61+import Squeal.PostgreSQL.Query

62+import Squeal.PostgreSQL.Render

63+import Squeal.PostgreSQL.Schema

64+

65+-- $setup

66+-- >>> import Squeal.PostgreSQL

67+

68+createFunction

69+ :: ( Has sch schemas schema

70+ , KnownSymbol fun

71+ , SOP.SListI args )

72+ => QualifiedAlias sch fun

73+ -> NP (TypeExpression schemas) args

74+ -> TypeExpression schemas ret

75+ -> FunctionDefinition schemas args ('Returns ret)

76+ -> Definition schemas (Alter sch (Create fun ('Function (args :=> 'Returns ret)) schema) schemas)

77+createFunction fun args ret fundef = UnsafeDefinition $

78+ "CREATE" <+> "FUNCTION" <+> renderSQL fun

79+ <+> parenthesized (renderCommaSeparated renderSQL args)

80+ <+> "RETURNS" <+> renderSQL ret <+> renderSQL fundef <> ";"

81+

82+createOrReplaceFunction

83+ :: ( Has sch schemas schema

84+ , KnownSymbol fun

85+ , SOP.SListI args )

86+ => QualifiedAlias sch fun

87+ -> NP (TypeExpression schemas) args

88+ -> TypeExpression schemas ret

89+ -> FunctionDefinition schemas args ('Returns ret)

90+ -> Definition schemas (Alter sch (CreateOrReplace fun ('Function (args :=> 'Returns ret)) schema) schemas)

91+createOrReplaceFunction fun args ret fundef = UnsafeDefinition $

92+ "CREATE" <+> "OR" <+> "REPLACE" <+> "FUNCTION" <+> renderSQL fun

93+ <+> parenthesized (renderCommaSeparated renderSQL args)

94+ <+> "RETURNS" <+> renderSQL ret <+> renderSQL fundef <> ";"

95+

96+languageSqlExpr

97+ :: Expression '[] '[] 'Ungrouped schemas args '[] ret

98+ -> FunctionDefinition schemas args ('Returns ret)

99+languageSqlExpr expr = UnsafeFunctionDefinition $

100+ "language sql as"

101+ <+> "$$" <+> renderSQL (values_ (expr `as` #ret)) <+> "$$"

102+

103+languageSqlQuery

104+ :: Query '[] '[] schemas args rets

105+ -> FunctionDefinition schemas args ('ReturnsTable rets)

106+languageSqlQuery qry = UnsafeFunctionDefinition $

107+ "language sql as" <+> "$$" <+> renderSQL qry <+> "$$"

108+

109+createSetFunction

110+ :: ( Has sch schemas schema

111+ , KnownSymbol fun

112+ , SOP.SListI args

113+ , SOP.SListI rets )

114+ => QualifiedAlias sch fun

115+ -> NP (TypeExpression schemas) args

116+ -> NP (Aliased (TypeExpression schemas)) rets

117+ -> FunctionDefinition schemas args ('ReturnsTable rets)

118+ -> Definition schemas (Alter sch (Create fun ('Function (args :=> 'ReturnsTable rets)) schema) schemas)

119+createSetFunction fun args rets fundef = UnsafeDefinition $

120+ "CREATE" <+> "FUNCTION" <+> renderSQL fun

121+ <+> parenthesized (renderCommaSeparated renderSQL args)

122+ <+> "RETURNS" <+> "TABLE"

123+ <+> parenthesized (renderCommaSeparated renderRet rets)

124+ <+> renderSQL fundef <> ";"

125+ where

126+ renderRet :: Aliased (TypeExpression s) r -> ByteString

127+ renderRet (ty `As` col) = renderSQL col <+> renderSQL ty

128+

129+createOrReplaceSetFunction

130+ :: ( Has sch schemas schema

131+ , KnownSymbol fun

132+ , SOP.SListI args

133+ , SOP.SListI rets )

134+ => QualifiedAlias sch fun

135+ -> NP (TypeExpression schemas) args

136+ -> NP (Aliased (TypeExpression schemas)) rets

137+ -> FunctionDefinition schemas args ('ReturnsTable rets)

138+ -> Definition schemas (Alter sch (CreateOrReplace fun ('Function (args :=> 'ReturnsTable rets)) schema) schemas)

139+createOrReplaceSetFunction fun args rets fundef = UnsafeDefinition $

140+ "CREATE" <+> "OR" <+> "REPLACE" <+> "FUNCTION" <+> renderSQL fun

141+ <+> parenthesized (renderCommaSeparated renderSQL args)

142+ <+> "RETURNS" <+> "TABLE"

143+ <+> parenthesized (renderCommaSeparated renderRet rets)

144+ <+> renderSQL fundef <> ";"

145+ where

146+ renderRet :: Aliased (TypeExpression s) r -> ByteString

147+ renderRet (ty `As` col) = renderSQL col <+> renderSQL ty

148+

149+createBinaryOp

150+ :: forall op fun sch schemas schema x y z.

151+ ( Has sch schemas schema

152+ , Has fun schema ('Function ('[x,y] :=> 'Returns z))

153+ , KnownSymbol op )

154+ => QualifiedAlias sch fun

155+ -> TypeExpression schemas x

156+ -> TypeExpression schemas y

157+ -> Definition schemas

158+ (Alter sch (Create op ('Operator ('BinaryOp x y z)) schema) schemas)

159+createBinaryOp fun x y = UnsafeDefinition $

160+ "CREATE" <+> "OPERATOR" <+> renderSymbol @op

161+ <+> parenthesized (commaSeparated opdef)

162+ where

163+ opdef =

164+ [ "FUNCTION" <+> "=" <+> renderSQL fun

165+ , "LEFTARG" <+> "=" <+> renderSQL x

166+ , "RIGHTARG" <+> "=" <+> renderSQL y ]

167+

168+createLeftOp

169+ :: forall op fun sch schemas schema x y.

170+ ( Has sch schemas schema

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

172+ , KnownSymbol op )

173+ => QualifiedAlias sch fun

174+ -> TypeExpression schemas x

175+ -> Definition schemas

176+ (Alter sch (Create op ('Operator ('LeftOp x y)) schema) schemas)

177+createLeftOp fun x = UnsafeDefinition $

178+ "CREATE" <+> "OPERATOR" <+> renderSymbol @op

179+ <+> parenthesized (commaSeparated opdef)

180+ where

181+ opdef =

182+ [ "FUNCTION" <+> "=" <+> renderSQL fun

183+ , "RIGHTARG" <+> "=" <+> renderSQL x ]

184+

185+createRightOp

186+ :: forall op fun sch schemas schema x y.

187+ ( Has sch schemas schema

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

189+ , KnownSymbol op )

190+ => QualifiedAlias sch fun

191+ -> TypeExpression schemas x

192+ -> Definition schemas

193+ (Alter sch (Create op ('Operator ('RightOp x y)) schema) schemas)

194+createRightOp fun x = UnsafeDefinition $

195+ "CREATE" <+> "OPERATOR" <+> renderSymbol @op

196+ <+> parenthesized (commaSeparated opdef)

197+ where

198+ opdef =

199+ [ "FUNCTION" <+> "=" <+> renderSQL fun

200+ , "LEFTARG" <+> "=" <+> renderSQL x ]

201+

202+dropFunction

203+ :: (Has sch schemas schema, KnownSymbol fun)

204+ => QualifiedAlias sch fun

205+ -- ^ name of the user defined function

206+ -> Definition schemas (Alter sch (DropSchemum fun 'Function schema) schemas)

207+dropFunction fun = UnsafeDefinition $

208+ "DROP" <+> "FUNCTION" <+> renderSQL fun <> ";"

209+

210+dropFunctionIfExists

211+ :: (Has sch schemas schema, KnownSymbol fun)

212+ => QualifiedAlias sch fun

213+ -- ^ name of the user defined function

214+ -> Definition schemas (Alter sch (DropSchemumIfExists fun 'Function schema) schemas)

215+dropFunctionIfExists fun = UnsafeDefinition $

216+ "DROP FUNCTION IF EXISTS" <+> renderSQL fun <> ";"

217+

218+dropOperator

219+ :: (Has sch schemas schema, KnownSymbol op)

220+ => QualifiedAlias sch op

221+ -- ^ name of the user defined operator

222+ -> Definition schemas (Alter sch (DropSchemum op 'Operator schema) schemas)

223+dropOperator op = UnsafeDefinition $

224+ "DROP" <+> "OPERATOR" <+> renderSQL op <> ";"

225+

226+dropOperatorIfExists

227+ :: (Has sch schemas schema, KnownSymbol op)

228+ => QualifiedAlias sch op

229+ -- ^ name of the user defined operator

230+ -> Definition schemas (Alter sch (DropSchemumIfExists op 'Operator schema) schemas)

231+dropOperatorIfExists op = UnsafeDefinition $

232+ "DROP OPERATOR IF EXISTS" <+> renderSQL op <> ";"

233+

234+newtype FunctionDefinition schemas args ret = UnsafeFunctionDefinition

235+ { renderFunctionDefinition :: ByteString }

236+ deriving (Eq,Show,GHC.Generic,NFData)

237+instance RenderSQL (FunctionDefinition schemas args ret) where

238+ renderSQL = renderFunctionDefinition

squeal-postgresql/src/Squeal/PostgreSQL/Definition/Index.hsnew file+159

@@ -0,0 +1,159 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.Index

3+Description: Create and drop index definitions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Create and drop index definitions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DerivingStrategies

17+ , FlexibleContexts

18+ , FlexibleInstances

19+ , GADTs

20+ , LambdaCase

21+ , MultiParamTypeClasses

22+ , OverloadedLabels

23+ , OverloadedStrings

24+ , RankNTypes

25+ , ScopedTypeVariables

26+ , TypeApplications

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableSuperClasses

30+#-}

31+

32+module Squeal.PostgreSQL.Definition.Index

33+ ( createIndex

34+ , createIndexIfNotExists

35+ , dropIndex

36+ , dropIndexIfExists

37+ , IndexMethod (..)

38+ , btree

39+ , hash

40+ , gist

41+ , spgist

42+ , gin

43+ , brin

44+ ) where

45+

46+import Data.ByteString

47+import GHC.TypeLits

48+

49+import qualified GHC.Generics as GHC

50+

51+import Squeal.PostgreSQL.Alias

52+import Squeal.PostgreSQL.Definition

53+import Squeal.PostgreSQL.Expression.Sort

54+import Squeal.PostgreSQL.Render

55+import Squeal.PostgreSQL.Schema

56+

57+-- $setup

58+-- >>> import Squeal.PostgreSQL

59+

60+{- |

61+>>> :{

62+type Table = '[] :=>

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

64+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]

65+:}

66+

67+>>> :{

68+let

69+ setup :: Definition (Public '[]) (Public '["tab" ::: 'Table Table, "ix" ::: 'Index 'Btree])

70+ setup =

71+ createTable #tab (nullable int `as` #a :* nullable real `as` #b) Nil >>>

72+ createIndex #ix #tab btree [#a & AscNullsFirst, #b & AscNullsLast]

73+in printSQL setup

74+:}

75+CREATE TABLE "tab" ("a" int NULL, "b" real NULL);

76+CREATE INDEX "ix" ON "tab" USING btree (("a") ASC NULLS FIRST, ("b") ASC NULLS LAST);

77+-}

78+createIndex

79+ :: (Has sch schemas schema, Has tab schema ('Table table), KnownSymbol ix)

80+ => Alias ix

81+ -> QualifiedAlias sch tab

82+ -> IndexMethod method

83+ -> [SortExpression '[] '[] 'Ungrouped schemas '[] '[tab ::: TableToRow table]]

84+ -> Definition schemas (Alter sch (Create ix ('Index method) schema) schemas)

85+createIndex ix tab method cols = UnsafeDefinition $

86+ "CREATE" <+> "INDEX" <+> renderSQL ix <+> "ON" <+> renderSQL tab

87+ <+> "USING" <+> renderSQL method

88+ <+> parenthesized (commaSeparated (renderIndex <$> cols))

89+ <> ";"

90+ where

91+ renderIndex = \case

92+ Asc expression -> parenthesized (renderSQL expression) <+> "ASC"

93+ Desc expression -> parenthesized (renderSQL expression) <+> "DESC"

94+ AscNullsFirst expression -> parenthesized (renderSQL expression)

95+ <+> "ASC NULLS FIRST"

96+ DescNullsFirst expression -> parenthesized (renderSQL expression)

97+ <+> "DESC NULLS FIRST"

98+ AscNullsLast expression -> parenthesized (renderSQL expression)

99+ <+> "ASC NULLS LAST"

100+ DescNullsLast expression -> parenthesized (renderSQL expression)

101+ <+> "DESC NULLS LAST"

102+

103+createIndexIfNotExists

104+ :: (Has sch schemas schema, Has tab schema ('Table table), KnownSymbol ix)

105+ => Alias ix

106+ -> QualifiedAlias sch tab

107+ -> IndexMethod method

108+ -> [SortExpression '[] '[] 'Ungrouped schemas '[] '[tab ::: TableToRow table]]

109+ -> Definition schemas (Alter sch (CreateIfNotExists ix ('Index method) schema) schemas)

110+createIndexIfNotExists ix tab method cols = UnsafeDefinition $

111+ "CREATE INDEX IF NOT EXISTS" <+> renderSQL ix <+> "ON" <+> renderSQL tab

112+ <+> "USING" <+> renderSQL method

113+ <+> parenthesized (commaSeparated (renderIndex <$> cols))

114+ <> ";"

115+ where

116+ renderIndex = \case

117+ Asc expression -> parenthesized (renderSQL expression) <+> "ASC"

118+ Desc expression -> parenthesized (renderSQL expression) <+> "DESC"

119+ AscNullsFirst expression -> parenthesized (renderSQL expression)

120+ <+> "ASC NULLS FIRST"

121+ DescNullsFirst expression -> parenthesized (renderSQL expression)

122+ <+> "DESC NULLS FIRST"

123+ AscNullsLast expression -> parenthesized (renderSQL expression)

124+ <+> "ASC NULLS LAST"

125+ DescNullsLast expression -> parenthesized (renderSQL expression)

126+ <+> "DESC NULLS LAST"

127+

128+newtype IndexMethod ty = UnsafeIndexMethod {renderIndexMethod :: ByteString}

129+ deriving stock (Eq, Ord, Show, GHC.Generic)

130+instance RenderSQL (IndexMethod ty) where renderSQL = renderIndexMethod

131+btree :: IndexMethod 'Btree

132+btree = UnsafeIndexMethod "btree"

133+hash :: IndexMethod 'Hash

134+hash = UnsafeIndexMethod "hash"

135+gist :: IndexMethod 'Gist

136+gist = UnsafeIndexMethod "gist"

137+spgist :: IndexMethod 'Spgist

138+spgist = UnsafeIndexMethod "spgist"

139+gin :: IndexMethod 'Gin

140+gin = UnsafeIndexMethod "gin"

141+brin :: IndexMethod 'Brin

142+brin = UnsafeIndexMethod "brin"

143+

144+-- |

145+-- >>> printSQL (dropIndex #ix :: Definition (Public '["ix" ::: 'Index 'Btree]) (Public '[]))

146+-- DROP INDEX "ix";

147+dropIndex

148+ :: (Has sch schemas schema, KnownSymbol ix)

149+ => QualifiedAlias sch ix

150+ -- ^ name of the user defined index

151+ -> Definition schemas (Alter sch (DropSchemum ix 'Index schema) schemas)

152+dropIndex ix = UnsafeDefinition $ "DROP" <+> "INDEX" <+> renderSQL ix <> ";"

153+

154+dropIndexIfExists

155+ :: (Has sch schemas schema, KnownSymbol ix)

156+ => QualifiedAlias sch ix

157+ -- ^ name of the user defined index

158+ -> Definition schemas (Alter sch (DropSchemumIfExists ix 'Index schema) schemas)

159+dropIndexIfExists ix = UnsafeDefinition $ "DROP INDEX IF EXISTS" <+> renderSQL ix <> ";"

squeal-postgresql/src/Squeal/PostgreSQL/Definition/Schema.hsnew file+96

@@ -0,0 +1,96 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.Schema

3+Description: Create and drop schema definitions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Create and drop schema definitions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DerivingStrategies

17+ , FlexibleContexts

18+ , FlexibleInstances

19+ , GADTs

20+ , LambdaCase

21+ , MultiParamTypeClasses

22+ , OverloadedLabels

23+ , OverloadedStrings

24+ , RankNTypes

25+ , ScopedTypeVariables

26+ , TypeApplications

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableSuperClasses

30+#-}

31+

32+module Squeal.PostgreSQL.Definition.Schema

33+ ( createSchema

34+ , createSchemaIfNotExists

35+ , dropSchema

36+ , dropSchemaIfExists

37+ ) where

38+

39+import GHC.TypeLits

40+

41+import Squeal.PostgreSQL.Alias

42+import Squeal.PostgreSQL.Definition

43+import Squeal.PostgreSQL.Render

44+import Squeal.PostgreSQL.Schema

45+

46+-- $setup

47+-- >>> import Squeal.PostgreSQL

48+

49+{- |

50+`createSchema` enters a new schema into the current database.

51+The schema name must be distinct from the name of any existing schema

52+in the current database.

53+

54+A schema is essentially a namespace: it contains named objects

55+(tables, data types, functions, and operators) whose names

56+can duplicate those of other objects existing in other schemas.

57+Named objects are accessed by `QualifiedAlias`es with the schema

58+name as a prefix.

59+-}

60+createSchema

61+ :: KnownSymbol sch

62+ => Alias sch

63+ -> Definition schemas (Create sch '[] schemas)

64+createSchema sch = UnsafeDefinition $

65+ "CREATE" <+> "SCHEMA" <+> renderSQL sch <> ";"

66+

67+{- | Idempotent version of `createSchema`. -}

68+createSchemaIfNotExists

69+ :: (KnownSymbol sch, Has sch schemas schema)

70+ => Alias sch

71+ -> Definition schemas (CreateIfNotExists sch '[] schemas)

72+createSchemaIfNotExists sch = UnsafeDefinition $

73+ "CREATE" <+> "SCHEMA" <+> "IF" <+> "NOT" <+> "EXISTS"

74+ <+> renderSQL sch <> ";"

75+

76+-- | >>> :{

77+-- let

78+-- definition :: Definition '["muh_schema" ::: schema, "public" ::: public] '["public" ::: public]

79+-- definition = dropSchema #muh_schema

80+-- :}

81+--

82+-- >>> printSQL definition

83+-- DROP SCHEMA "muh_schema";

84+dropSchema

85+ :: KnownSymbol sch

86+ => Alias sch

87+ -- ^ user defined schema

88+ -> Definition schemas (Drop sch schemas)

89+dropSchema sch = UnsafeDefinition $ "DROP SCHEMA" <+> renderSQL sch <> ";"

90+

91+dropSchemaIfExists

92+ :: KnownSymbol sch

93+ => Alias sch

94+ -- ^ user defined schema

95+ -> Definition schemas (DropIfExists sch schemas)

96+dropSchemaIfExists sch = UnsafeDefinition $ "DROP SCHEMA" <+> renderSQL sch <> ";"

squeal-postgresql/src/Squeal/PostgreSQL/Definition/Table.hsnew file+500

@@ -0,0 +1,500 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.Table

3+Description: Create, drop and alter table definitions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Create, drop and alter table definitions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DerivingStrategies

17+ , FlexibleContexts

18+ , FlexibleInstances

19+ , GADTs

20+ , LambdaCase

21+ , MultiParamTypeClasses

22+ , OverloadedLabels

23+ , OverloadedStrings

24+ , RankNTypes

25+ , ScopedTypeVariables

26+ , TypeApplications

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableSuperClasses

30+#-}

31+

32+module Squeal.PostgreSQL.Definition.Table

33+ ( createTable

34+ , createTableIfNotExists

35+ , dropTable

36+ , dropTableIfExists

37+ , alterTable

38+ , alterTableIfExists

39+ , alterTableRename

40+ , alterTableIfExistsRename

41+ , AlterTable (..)

42+ , addConstraint

43+ , dropConstraint

44+ , AddColumn (..)

45+ , dropColumn

46+ , renameColumn

47+ , alterColumn

48+ , AlterColumn (..)

49+ , setDefault

50+ , dropDefault

51+ , setNotNull

52+ , dropNotNull

53+ , alterType

54+ ) where

55+

56+import Control.DeepSeq

57+import Data.ByteString

58+import GHC.TypeLits

59+

60+import qualified Generics.SOP as SOP

61+import qualified GHC.Generics as GHC

62+

63+import Squeal.PostgreSQL.Alias

64+import Squeal.PostgreSQL.Definition

65+import Squeal.PostgreSQL.Definition.Table.Constraint

66+import Squeal.PostgreSQL.Expression

67+import Squeal.PostgreSQL.Expression.Type

68+import Squeal.PostgreSQL.List

69+import Squeal.PostgreSQL.Render

70+import Squeal.PostgreSQL.Schema

71+

72+-- $setup

73+-- >>> import Squeal.PostgreSQL

74+

75+{- | `createTable` adds a table to the schema.

76+

77+>>> :set -XOverloadedLabels

78+>>> :{

79+type Table = '[] :=>

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

81+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]

82+:}

83+

84+>>> :{

85+let

86+ setup :: Definition (Public '[]) (Public '["tab" ::: 'Table Table])

87+ setup = createTable #tab

88+ (nullable int `as` #a :* nullable real `as` #b) Nil

89+in printSQL setup

90+:}

91+CREATE TABLE "tab" ("a" int NULL, "b" real NULL);

92+-}

93+createTable

94+ :: ( KnownSymbol sch

95+ , KnownSymbol tab

96+ , columns ~ (col ': cols)

97+ , SOP.SListI columns

98+ , SOP.SListI constraints

99+ , Has sch schemas0 schema0

100+ , schemas1 ~ Alter sch (Create tab ('Table (constraints :=> columns)) schema0) schemas0 )

101+ => QualifiedAlias sch tab -- ^ the name of the table to add

102+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns

103+ -- ^ the names and datatype of each column

104+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints

105+ -- ^ constraints that must hold for the table

106+ -> Definition schemas0 schemas1

107+createTable tab columns constraints = UnsafeDefinition $

108+ "CREATE TABLE" <+> renderCreation tab columns constraints

109+

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

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

112+`createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in

113+the `Category` of `Definition`s.

114+

115+>>> :set -XOverloadedLabels -XTypeApplications

116+>>> :{

117+type Table = '[] :=>

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

119+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]

120+:}

121+

122+>>> type Schemas = Public '["tab" ::: 'Table Table]

123+

124+>>> :{

125+let

126+ setup :: Definition Schemas Schemas

127+ setup = createTableIfNotExists #tab

128+ (nullable int `as` #a :* nullable real `as` #b) Nil

129+in printSQL setup

130+:}

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

132+-}

133+createTableIfNotExists

134+ :: ( KnownSymbol sch

135+ , KnownSymbol tab

136+ , columns ~ (col ': cols)

137+ , SOP.SListI columns

138+ , SOP.SListI constraints

139+ , Has sch schemas0 schema0

140+ , schemas1 ~ Alter sch (CreateIfNotExists tab ('Table (constraints :=> columns)) schema0) schemas0 )

141+ => QualifiedAlias sch tab -- ^ the name of the table to add

142+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns

143+ -- ^ the names and datatype of each column

144+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints

145+ -- ^ constraints that must hold for the table

146+ -> Definition schemas0 schemas1

147+createTableIfNotExists tab columns constraints = UnsafeDefinition $

148+ "CREATE TABLE IF NOT EXISTS"

149+ <+> renderCreation tab columns constraints

150+

151+-- helper function for `createTable` and `createTableIfNotExists`

152+renderCreation

153+ :: ( KnownSymbol sch

154+ , KnownSymbol tab

155+ , SOP.SListI columns

156+ , SOP.SListI constraints )

157+ => QualifiedAlias sch tab -- ^ the name of the table to add

158+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns

159+ -- ^ the names and datatype of each column

160+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints

161+ -- ^ constraints that must hold for the table

162+ -> ByteString

163+renderCreation tab columns constraints = renderSQL tab

164+ <+> parenthesized

165+ ( renderCommaSeparated renderColumnDef columns

166+ <> ( case constraints of

167+ Nil -> ""

168+ _ -> ", " <>

169+ renderCommaSeparated renderConstraint constraints ) )

170+ <> ";"

171+ where

172+ renderColumnDef :: Aliased (ColumnTypeExpression schemas) x -> ByteString

173+ renderColumnDef (ty `As` column) =

174+ renderSQL column <+> renderColumnTypeExpression ty

175+ renderConstraint

176+ :: Aliased (TableConstraintExpression sch tab schemas) constraint

177+ -> ByteString

178+ renderConstraint (constraint `As` alias) =

179+ "CONSTRAINT" <+> renderSQL alias <+> renderSQL constraint

180+

181+-- | `dropTable` removes a table from the schema.

182+--

183+-- >>> :{

184+-- let

185+-- definition :: Definition '["public" ::: '["muh_table" ::: 'Table t]] (Public '[])

186+-- definition = dropTable #muh_table

187+-- :}

188+--

189+-- >>> printSQL definition

190+-- DROP TABLE "muh_table";

191+dropTable

192+ :: ( Has sch schemas schema

193+ , KnownSymbol tab )

194+ => QualifiedAlias sch tab -- ^ table to remove

195+ -> Definition schemas (Alter sch (DropSchemum tab 'Table schema) schemas)

196+dropTable tab = UnsafeDefinition $ "DROP TABLE" <+> renderSQL tab <> ";"

197+

198+dropTableIfExists

199+ :: ( Has sch schemas schema

200+ , KnownSymbol tab)

201+ => QualifiedAlias sch tab -- ^ table to remove

202+ -> Definition schemas (Alter sch (DropSchemumIfExists tab 'Table schema) schemas)

203+dropTableIfExists tab = UnsafeDefinition $ "DROP TABLE IF EXISTS" <+> renderSQL tab <> ";"

204+

205+-- | `alterTable` changes the definition of a table from the schema.

206+alterTable

207+ :: (Has sch schemas schema, KnownSymbol tab)

208+ => QualifiedAlias sch tab -- ^ table to alter

209+ -> AlterTable sch tab schemas table -- ^ alteration to perform

210+ -> Definition schemas (Alter sch (Alter tab ('Table table) schema) schemas)

211+alterTable tab alteration = UnsafeDefinition $

212+ "ALTER TABLE"

213+ <+> renderSQL tab

214+ <+> renderAlterTable alteration

215+ <> ";"

216+

217+-- | `alterTable` changes the definition of a table from the schema.

218+alterTableIfExists

219+ :: (Has sch schemas schema, KnownSymbol tab)

220+ => QualifiedAlias sch tab -- ^ table to alter

221+ -> AlterTable sch tab schemas table -- ^ alteration to perform

222+ -> Definition schemas (Alter sch (AlterIfExists tab ('Table table) schema) schemas)

223+alterTableIfExists tab alteration = UnsafeDefinition $

224+ "ALTER TABLE IF EXISTS"

225+ <+> renderSQL tab

226+ <+> renderAlterTable alteration

227+ <> ";"

228+

229+-- | `alterTableRename` changes the name of a table from the schema.

230+--

231+-- >>> printSQL $ alterTableRename #foo #bar

232+-- ALTER TABLE "foo" RENAME TO "bar";

233+alterTableRename

234+ :: (KnownSymbol tab0, KnownSymbol tab1)

235+ => Alias tab0 -- ^ table to rename

236+ -> Alias tab1 -- ^ what to rename it

237+ -> Definition schema (Rename tab0 tab1 schema)

238+alterTableRename tab0 tab1 = UnsafeDefinition $

239+ "ALTER TABLE" <+> renderSQL tab0

240+ <+> "RENAME TO" <+> renderSQL tab1 <> ";"

241+

242+alterTableIfExistsRename

243+ :: (KnownSymbol tab0, KnownSymbol tab1)

244+ => Alias tab0 -- ^ table to rename

245+ -> Alias tab1 -- ^ what to rename it

246+ -> Definition schema (RenameIfExists tab0 tab1 schema)

247+alterTableIfExistsRename tab0 tab1 = UnsafeDefinition $

248+ "ALTER TABLE IF EXISTS" <+> renderSQL tab0

249+ <+> "RENAME TO" <+> renderSQL tab1 <> ";"

250+

251+-- | An `AlterTable` describes the alteration to perform on the columns

252+-- of a table.

253+newtype AlterTable

254+ (sch :: Symbol)

255+ (tab :: Symbol)

256+ (schemas :: SchemasType)

257+ (table :: TableType) =

258+ UnsafeAlterTable {renderAlterTable :: ByteString}

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

260+

261+-- | An `addConstraint` adds a table constraint.

262+--

263+-- >>> :{

264+-- let

265+-- definition :: Definition

266+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]

267+-- '["public" ::: '["tab" ::: 'Table ('["positive" ::: 'Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]

268+-- definition = alterTable #tab (addConstraint #positive (check #col (#col .> 0)))

269+-- in printSQL definition

270+-- :}

271+-- ALTER TABLE "tab" ADD CONSTRAINT "positive" CHECK (("col" > 0));

272+addConstraint

273+ :: ( KnownSymbol alias

274+ , Has sch schemas schema

275+ , Has tab schema ('Table table0)

276+ , table0 ~ (constraints :=> columns)

277+ , table1 ~ (Create alias constraint constraints :=> columns) )

278+ => Alias alias

279+ -> TableConstraintExpression sch tab schemas constraint

280+ -- ^ constraint to add

281+ -> AlterTable sch tab schemas table1

282+addConstraint alias constraint = UnsafeAlterTable $

283+ "ADD" <+> "CONSTRAINT" <+> renderSQL alias

284+ <+> renderSQL constraint

285+

286+-- | A `dropConstraint` drops a table constraint.

287+--

288+-- >>> :{

289+-- let

290+-- definition :: Definition

291+-- '["public" ::: '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]

292+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]

293+-- definition = alterTable #tab (dropConstraint #positive)

294+-- in printSQL definition

295+-- :}

296+-- ALTER TABLE "tab" DROP CONSTRAINT "positive";

297+dropConstraint

298+ :: ( KnownSymbol constraint

299+ , Has sch schemas schema

300+ , Has tab schema ('Table table0)

301+ , table0 ~ (constraints :=> columns)

302+ , table1 ~ (Drop constraint constraints :=> columns) )

303+ => Alias constraint

304+ -- ^ constraint to drop

305+ -> AlterTable sch tab schemas table1

306+dropConstraint constraint = UnsafeAlterTable $

307+ "DROP" <+> "CONSTRAINT" <+> renderSQL constraint

308+

309+-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.

310+class AddColumn ty where

311+ -- | `addColumn` adds a new column, initially filled with whatever

312+ -- default value is given or with @NULL@.

313+ --

314+ -- >>> :{

315+ -- let

316+ -- definition :: Definition

317+ -- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]

318+ -- '["public" ::: '["tab" ::: 'Table ('[] :=>

319+ -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

320+ -- , "col2" ::: 'Def :=> 'Null 'PGtext ])]]

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

322+ -- in printSQL definition

323+ -- :}

324+ -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL DEFAULT E'foo';

325+ --

326+ -- >>> :{

327+ -- let

328+ -- definition :: Definition

329+ -- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]

330+ -- '["public" ::: '["tab" ::: 'Table ('[] :=>

331+ -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

332+ -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]]

333+ -- definition = alterTable #tab (addColumn #col2 (text & nullable))

334+ -- in printSQL definition

335+ -- :}

336+ -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL;

337+ addColumn

338+ :: ( KnownSymbol column

339+ , Has sch schemas schema

340+ , Has tab schema ('Table table0)

341+ , table0 ~ (constraints :=> columns) )

342+ => Alias column -- ^ column to add

343+ -> ColumnTypeExpression schemas ty -- ^ type of the new column

344+ -> AlterTable sch tab schemas (constraints :=> Create column ty columns)

345+ addColumn column ty = UnsafeAlterTable $

346+ "ADD COLUMN" <+> renderSQL column <+> renderColumnTypeExpression ty

347+instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)

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

349+

350+-- | A `dropColumn` removes a column. Whatever data was in the column

351+-- disappears. Table constraints involving the column are dropped, too.

352+-- However, if the column is referenced by a foreign key constraint of

353+-- another table, PostgreSQL will not silently drop that constraint.

354+--

355+-- >>> :{

356+-- let

357+-- definition :: Definition

358+-- '["public" ::: '["tab" ::: 'Table ('[] :=>

359+-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4

360+-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]]

361+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]

362+-- definition = alterTable #tab (dropColumn #col2)

363+-- in printSQL definition

364+-- :}

365+-- ALTER TABLE "tab" DROP COLUMN "col2";

366+dropColumn

367+ :: ( KnownSymbol column

368+ , Has sch schemas schema

369+ , Has tab schema ('Table table0)

370+ , table0 ~ (constraints :=> columns)

371+ , table1 ~ (constraints :=> Drop column columns) )

372+ => Alias column -- ^ column to remove

373+ -> AlterTable sch tab schemas table1

374+dropColumn column = UnsafeAlterTable $

375+ "DROP COLUMN" <+> renderSQL column

376+

377+-- | A `renameColumn` renames a column.

378+--

379+-- >>> :{

380+-- let

381+-- definition :: Definition

382+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4])]]

383+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4])]]

384+-- definition = alterTable #tab (renameColumn #foo #bar)

385+-- in printSQL definition

386+-- :}

387+-- ALTER TABLE "tab" RENAME COLUMN "foo" TO "bar";

388+renameColumn

389+ :: ( KnownSymbol column0

390+ , KnownSymbol column1

391+ , Has sch schemas schema

392+ , Has tab schema ('Table table0)

393+ , table0 ~ (constraints :=> columns)

394+ , table1 ~ (constraints :=> Rename column0 column1 columns) )

395+ => Alias column0 -- ^ column to rename

396+ -> Alias column1 -- ^ what to rename the column

397+ -> AlterTable sch tab schemas table1

398+renameColumn column0 column1 = UnsafeAlterTable $

399+ "RENAME COLUMN" <+> renderSQL column0 <+> "TO" <+> renderSQL column1

400+

401+-- | An `alterColumn` alters a single column.

402+alterColumn

403+ :: ( KnownSymbol column

404+ , Has sch schemas schema

405+ , Has tab schema ('Table table0)

406+ , table0 ~ (constraints :=> columns)

407+ , Has column columns ty0

408+ , table1 ~ (constraints :=> Alter column ty1 columns))

409+ => Alias column -- ^ column to alter

410+ -> AlterColumn schemas ty0 ty1 -- ^ alteration to perform

411+ -> AlterTable sch tab schemas table1

412+alterColumn column alteration = UnsafeAlterTable $

413+ "ALTER COLUMN" <+> renderSQL column <+> renderAlterColumn alteration

414+

415+-- | An `AlterColumn` describes the alteration to perform on a single column.

416+newtype AlterColumn (schemas :: SchemasType) (ty0 :: ColumnType) (ty1 :: ColumnType) =

417+ UnsafeAlterColumn {renderAlterColumn :: ByteString}

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

419+

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

421+-- affect any existing rows in the table, it just changes the default for

422+-- future insert and update commands.

423+--

424+-- >>> :{

425+-- let

426+-- definition :: Definition

427+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]

428+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]]

429+-- definition = alterTable #tab (alterColumn #col (setDefault 5))

430+-- in printSQL definition

431+-- :}

432+-- ALTER TABLE "tab" ALTER COLUMN "col" SET DEFAULT 5;

433+setDefault

434+ :: Expression '[] '[] 'Ungrouped schemas '[] '[] ty -- ^ default value to set

435+ -> AlterColumn schemas (constraint :=> ty) ('Def :=> ty)

436+setDefault expression = UnsafeAlterColumn $

437+ "SET DEFAULT" <+> renderExpression expression

438+

439+-- | A `dropDefault` removes any default value for a column.

440+--

441+-- >>> :{

442+-- let

443+-- definition :: Definition

444+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]]

445+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]

446+-- definition = alterTable #tab (alterColumn #col dropDefault)

447+-- in printSQL definition

448+-- :}

449+-- ALTER TABLE "tab" ALTER COLUMN "col" DROP DEFAULT;

450+dropDefault :: AlterColumn schemas ('Def :=> ty) ('NoDef :=> ty)

451+dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"

452+

453+-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.

454+-- The constraint will be checked immediately, so the table data must satisfy

455+-- the constraint before it can be added.

456+--

457+-- >>> :{

458+-- let

459+-- definition :: Definition

460+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]

461+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]

462+-- definition = alterTable #tab (alterColumn #col setNotNull)

463+-- in printSQL definition

464+-- :}

465+-- ALTER TABLE "tab" ALTER COLUMN "col" SET NOT NULL;

466+setNotNull

467+ :: AlterColumn schemas (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)

468+setNotNull = UnsafeAlterColumn $ "SET NOT NULL"

469+

470+-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.

471+--

472+-- >>> :{

473+-- let

474+-- definition :: Definition

475+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]

476+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]

477+-- definition = alterTable #tab (alterColumn #col dropNotNull)

478+-- in printSQL definition

479+-- :}

480+-- ALTER TABLE "tab" ALTER COLUMN "col" DROP NOT NULL;

481+dropNotNull

482+ :: AlterColumn schemas (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)

483+dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"

484+

485+-- | An `alterType` converts a column to a different data type.

486+-- This will succeed only if each existing entry in the column can be

487+-- converted to the new type by an implicit cast.

488+--

489+-- >>> :{

490+-- let

491+-- definition :: Definition

492+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]

493+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]]

494+-- definition =

495+-- alterTable #tab (alterColumn #col (alterType (numeric & notNullable)))

496+-- in printSQL definition

497+-- :}

498+-- ALTER TABLE "tab" ALTER COLUMN "col" TYPE numeric NOT NULL;

499+alterType :: ColumnTypeExpression schemas ty -> AlterColumn schemas ty0 ty

500+alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty

squeal-postgresql/src/Squeal/PostgreSQL/Definition/Table/Constraint.hsnew file+339

@@ -0,0 +1,339 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.Table.Constraint

3+Description: Table constraint expressions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Table constraint expressions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DerivingStrategies

17+ , FlexibleContexts

18+ , FlexibleInstances

19+ , GADTs

20+ , LambdaCase

21+ , MultiParamTypeClasses

22+ , OverloadedLabels

23+ , OverloadedStrings

24+ , RankNTypes

25+ , ScopedTypeVariables

26+ , TypeApplications

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableSuperClasses

30+#-}

31+

32+module Squeal.PostgreSQL.Definition.Table.Constraint

33+ ( TableConstraintExpression (..)

34+ , check

35+ , unique

36+ , primaryKey

37+ , foreignKey

38+ , ForeignKeyed

39+ , OnDeleteClause (..)

40+ , OnUpdateClause (..)

41+ ) where

42+

43+import Control.DeepSeq

44+import Data.ByteString

45+import GHC.TypeLits

46+

47+import qualified Generics.SOP as SOP

48+import qualified GHC.Generics as GHC

49+

50+import Squeal.PostgreSQL.Alias

51+import Squeal.PostgreSQL.Expression.Logic

52+import Squeal.PostgreSQL.List

53+import Squeal.PostgreSQL.Render

54+import Squeal.PostgreSQL.Schema

55+

56+-- $setup

57+-- >>> import Squeal.PostgreSQL

58+

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

60+-- table. For many applications, however, the constraint they provide is

61+-- too coarse. For example, a column containing a product price should

62+-- probably only accept positive values. But there is no standard data type

63+-- that accepts only positive numbers. Another issue is that you might want

64+-- to constrain column data with respect to other columns or rows.

65+-- For example, in a table containing product information,

66+-- there should be only one row for each product number.

67+-- `TableConstraint`s give you as much control over the data in your tables

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

69+-- violate a constraint, an error is raised. This applies

70+-- even if the value came from the default value definition.

71+newtype TableConstraintExpression

72+ (sch :: Symbol)

73+ (tab :: Symbol)

74+ (schemas :: SchemasType)

75+ (constraint :: TableConstraint)

76+ = UnsafeTableConstraintExpression

77+ { renderTableConstraintExpression :: ByteString }

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

79+instance RenderSQL

80+ (TableConstraintExpression sch tab schemas constraint) where

81+ renderSQL = renderTableConstraintExpression

82+

83+{-| A `check` constraint is the most generic `TableConstraint` type.

84+It allows you to specify that the value in a certain column must satisfy

85+a Boolean (truth-value) expression.

86+

87+>>> :{

88+type Schema = '[

89+ "tab" ::: 'Table ('[ "inequality" ::: 'Check '["a","b"]] :=> '[

90+ "a" ::: 'NoDef :=> 'NotNull 'PGint4,

91+ "b" ::: 'NoDef :=> 'NotNull 'PGint4

92+ ])]

93+:}

94+

95+>>> :{

96+let

97+ definition :: Definition (Public '[]) (Public Schema)

98+ definition = createTable #tab

99+ ( (int & notNullable) `as` #a :*

100+ (int & notNullable) `as` #b )

101+ ( check (#a :* #b) (#a .> #b) `as` #inequality )

102+:}

103+

104+>>> printSQL definition

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

106+-}

107+check

108+ :: ( Has sch schemas schema

109+ , Has tab schema ('Table table)

110+ , HasAll aliases (TableToRow table) subcolumns )

111+ => NP Alias aliases

112+ -- ^ specify the subcolumns which are getting checked

113+ -> (forall t. Condition '[] '[] 'Ungrouped schemas '[] '[t ::: subcolumns])

114+ -- ^ a closed `Condition` on those subcolumns

115+ -> TableConstraintExpression sch tab schemas ('Check aliases)

116+check _cols condition = UnsafeTableConstraintExpression $

117+ "CHECK" <+> parenthesized (renderSQL condition)

118+

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

120+or a group of columns, is unique among all the rows in the table.

121+

122+>>> :{

123+type Schema = '[

124+ "tab" ::: 'Table( '[ "uq_a_b" ::: 'Unique '["a","b"]] :=> '[

125+ "a" ::: 'NoDef :=> 'Null 'PGint4,

126+ "b" ::: 'NoDef :=> 'Null 'PGint4

127+ ])]

128+:}

129+

130+>>> :{

131+let

132+ definition :: Definition (Public '[]) (Public Schema)

133+ definition = createTable #tab

134+ ( (int & nullable) `as` #a :*

135+ (int & nullable) `as` #b )

136+ ( unique (#a :* #b) `as` #uq_a_b )

137+:}

138+

139+>>> printSQL definition

140+CREATE TABLE "tab" ("a" int NULL, "b" int NULL, CONSTRAINT "uq_a_b" UNIQUE ("a", "b"));

141+-}

142+unique

143+ :: ( Has sch schemas schema

144+ , Has tab schema('Table table)

145+ , HasAll aliases (TableToRow table) subcolumns )

146+ => NP Alias aliases

147+ -- ^ specify subcolumns which together are unique for each row

148+ -> TableConstraintExpression sch tab schemas ('Unique aliases)

149+unique columns = UnsafeTableConstraintExpression $

150+ "UNIQUE" <+> parenthesized (renderSQL columns)

151+

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

153+can be used as a unique identifier for rows in the table.

154+This requires that the values be both unique and not null.

155+

156+>>> :{

157+type Schema = '[

158+ "tab" ::: 'Table ('[ "pk_id" ::: 'PrimaryKey '["id"]] :=> '[

159+ "id" ::: 'Def :=> 'NotNull 'PGint4,

160+ "name" ::: 'NoDef :=> 'NotNull 'PGtext

161+ ])]

162+:}

163+

164+>>> :{

165+let

166+ definition :: Definition (Public '[]) (Public Schema)

167+ definition = createTable #tab

168+ ( serial `as` #id :*

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

170+ ( primaryKey #id `as` #pk_id )

171+:}

172+

173+>>> printSQL definition

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

175+-}

176+primaryKey

177+ :: ( Has sch schemas schema

178+ , Has tab schema ('Table table)

179+ , HasAll aliases (TableToColumns table) subcolumns

180+ , AllNotNull subcolumns )

181+ => NP Alias aliases

182+ -- ^ specify the subcolumns which together form a primary key.

183+ -> TableConstraintExpression sch tab schemas ('PrimaryKey aliases)

184+primaryKey columns = UnsafeTableConstraintExpression $

185+ "PRIMARY KEY" <+> parenthesized (renderSQL columns)

186+

187+{-| A `foreignKey` specifies that the values in a column

188+(or a group of columns) must match the values appearing in some row of

189+another table. We say this maintains the referential integrity

190+between two related tables.

191+

192+>>> :{

193+type Schema =

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

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

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

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

198+ ])

199+ , "emails" ::: 'Table (

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

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

202+ ] :=>

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

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

205+ , "email" ::: 'NoDef :=> 'Null 'PGtext

206+ ])

207+ ]

208+:}

209+

210+>>> :{

211+let

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

213+ setup =

214+ createTable #users

215+ ( serial `as` #id :*

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

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

218+ createTable #emails

219+ ( serial `as` #id :*

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

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

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

223+ foreignKey #user_id #users #id

224+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

225+in printSQL setup

226+:}

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

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

229+

230+A `foreignKey` can even be a table self-reference.

231+

232+>>> :{

233+type Schema =

234+ '[ "employees" ::: 'Table (

235+ '[ "employees_pk" ::: 'PrimaryKey '["id"]

236+ , "employees_employer_fk" ::: 'ForeignKey '["employer_id"] "employees" '["id"]

237+ ] :=>

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

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

240+ , "employer_id" ::: 'NoDef :=> 'Null 'PGint4

241+ ])

242+ ]

243+:}

244+

245+>>> :{

246+let

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

248+ setup =

249+ createTable #employees

250+ ( serial `as` #id :*

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

252+ (integer & nullable) `as` #employer_id )

253+ ( primaryKey #id `as` #employees_pk :*

254+ foreignKey #employer_id #employees #id

255+ OnDeleteCascade OnUpdateCascade `as` #employees_employer_fk )

256+in printSQL setup

257+:}

258+CREATE TABLE "employees" ("id" serial, "name" text NOT NULL, "employer_id" integer NULL, CONSTRAINT "employees_pk" PRIMARY KEY ("id"), CONSTRAINT "employees_employer_fk" FOREIGN KEY ("employer_id") REFERENCES "employees" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

259+-}

260+foreignKey

261+ :: (ForeignKeyed schemas sch schema child parent

262+ table reftable

263+ columns refcolumns

264+ constraints cols

265+ reftys tys )

266+ => NP Alias columns

267+ -- ^ column or columns in the table

268+ -> Alias parent

269+ -- ^ reference table

270+ -> NP Alias refcolumns

271+ -- ^ reference column or columns in the reference table

272+ -> OnDeleteClause

273+ -- ^ what to do when reference is deleted

274+ -> OnUpdateClause

275+ -- ^ what to do when reference is updated

276+ -> TableConstraintExpression sch child schemas

277+ ('ForeignKey columns parent refcolumns)

278+foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $

279+ "FOREIGN KEY" <+> parenthesized (renderSQL keys)

280+ <+> "REFERENCES" <+> renderSQL parent

281+ <+> parenthesized (renderSQL refs)

282+ <+> renderSQL ondel

283+ <+> renderSQL onupd

284+

285+-- | A constraint synonym between types involved in a foreign key constraint.

286+type ForeignKeyed schemas

287+ sch

288+ schema

289+ child parent

290+ table reftable

291+ columns refcolumns

292+ constraints cols

293+ reftys tys =

294+ ( Has sch schemas schema

295+ , Has child schema ('Table table)

296+ , Has parent schema ('Table reftable)

297+ , HasAll columns (TableToColumns table) tys

298+ , reftable ~ (constraints :=> cols)

299+ , HasAll refcolumns cols reftys

300+ , SOP.AllZip SamePGType tys reftys

301+ , Uniquely refcolumns constraints )

302+

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

304+data OnDeleteClause

305+ = OnDeleteNoAction

306+ -- ^ if any referencing rows still exist when the constraint is checked,

307+ -- an error is raised

308+ | OnDeleteRestrict -- ^ prevents deletion of a referenced row

309+ | OnDeleteCascade

310+ -- ^ specifies that when a referenced row is deleted,

311+ -- row(s) referencing it should be automatically deleted as well

312+ deriving (GHC.Generic,Show,Eq,Ord)

313+instance NFData OnDeleteClause

314+-- | Render `OnDeleteClause`.

315+instance RenderSQL OnDeleteClause where

316+ renderSQL = \case

317+ OnDeleteNoAction -> "ON DELETE NO ACTION"

318+ OnDeleteRestrict -> "ON DELETE RESTRICT"

319+ OnDeleteCascade -> "ON DELETE CASCADE"

320+

321+-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked

322+-- when a referenced column is changed (updated).

323+data OnUpdateClause

324+ = OnUpdateNoAction

325+ -- ^ if any referencing rows has not changed when the constraint is checked,

326+ -- an error is raised

327+ | OnUpdateRestrict -- ^ prevents update of a referenced row

328+ | OnUpdateCascade

329+ -- ^ the updated values of the referenced column(s) should be copied

330+ -- into the referencing row(s)

331+ deriving (GHC.Generic,Show,Eq,Ord)

332+instance NFData OnUpdateClause

333+

334+-- | Render `OnUpdateClause`.

335+instance RenderSQL OnUpdateClause where

336+ renderSQL = \case

337+ OnUpdateNoAction -> "ON UPDATE NO ACTION"

338+ OnUpdateRestrict -> "ON UPDATE RESTRICT"

339+ OnUpdateCascade -> "ON UPDATE CASCADE"

squeal-postgresql/src/Squeal/PostgreSQL/Definition/Type.hsnew file+229

@@ -0,0 +1,229 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.Type

3+Description: Create and drop type definitions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Create and drop type definitions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DerivingStrategies

17+ , FlexibleContexts

18+ , FlexibleInstances

19+ , GADTs

20+ , LambdaCase

21+ , MultiParamTypeClasses

22+ , OverloadedLabels

23+ , OverloadedStrings

24+ , RankNTypes

25+ , ScopedTypeVariables

26+ , TypeApplications

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableSuperClasses

30+#-}

31+

32+module Squeal.PostgreSQL.Definition.Type

33+ ( createTypeEnum

34+ , createTypeEnumFrom

35+ , createTypeComposite

36+ , createTypeCompositeFrom

37+ , createTypeRange

38+ , createDomain

39+ , dropType

40+ , dropTypeIfExists

41+ ) where

42+

43+import Data.ByteString

44+import Data.Monoid

45+import GHC.TypeLits

46+import Prelude hiding ((.), id)

47+

48+import qualified Generics.SOP as SOP

49+

50+import Squeal.PostgreSQL.Alias

51+import Squeal.PostgreSQL.Expression.Logic

52+import Squeal.PostgreSQL.Expression.Type

53+import Squeal.PostgreSQL.Definition

54+import Squeal.PostgreSQL.List

55+import Squeal.PostgreSQL.PG

56+import Squeal.PostgreSQL.Render

57+import Squeal.PostgreSQL.Schema

58+

59+-- $setup

60+-- >>> import Squeal.PostgreSQL

61+-- >>> import qualified GHC.Generics as GHC

62+-- >>> import qualified Generics.SOP as SOP

63+

64+-- | Enumerated types are created using the `createTypeEnum` command, for example

65+--

66+-- >>> printSQL $ (createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy") :: Definition (Public '[]) '["public" ::: '["mood" ::: 'Typedef ('PGenum '["sad","ok","happy"])]])

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

68+createTypeEnum

69+ :: (KnownSymbol enum, Has sch schemas schema, SOP.All KnownSymbol labels)

70+ => QualifiedAlias sch enum

71+ -- ^ name of the user defined enumerated type

72+ -> NP PGlabel labels

73+ -- ^ labels of the enumerated type

74+ -> Definition schemas (Alter sch (Create enum ('Typedef ('PGenum labels)) schema) schemas)

75+createTypeEnum enum labels = UnsafeDefinition $

76+ "CREATE" <+> "TYPE" <+> renderSQL enum <+> "AS" <+> "ENUM" <+>

77+ parenthesized (renderSQL labels) <> ";"

78+

79+-- | Enumerated types can also be generated from a Haskell type, for example

80+--

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

82+-- >>> instance SOP.Generic Schwarma

83+-- >>> instance SOP.HasDatatypeInfo Schwarma

84+-- >>> :{

85+-- let

86+-- createSchwarma :: Definition (Public '[]) '["public" ::: '["schwarma" ::: 'Typedef (PG (Enumerated Schwarma))]]

87+-- createSchwarma = createTypeEnumFrom @Schwarma #schwarma

88+-- in

89+-- printSQL createSchwarma

90+-- :}

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

92+createTypeEnumFrom

93+ :: forall hask sch enum schemas schema.

94+ ( SOP.Generic hask

95+ , SOP.All KnownSymbol (LabelsPG hask)

96+ , KnownSymbol enum

97+ , Has sch schemas schema )

98+ => QualifiedAlias sch enum

99+ -- ^ name of the user defined enumerated type

100+ -> Definition schemas (Alter sch (Create enum ('Typedef (PG (Enumerated hask))) schema) schemas)

101+createTypeEnumFrom enum = createTypeEnum enum

102+ (SOP.hpure label :: NP PGlabel (LabelsPG hask))

103+

104+{- | `createTypeComposite` creates a composite type. The composite type is

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

106+

107+>>> :{

108+type PGcomplex = 'PGcomposite

109+ '[ "real" ::: 'NotNull 'PGfloat8

110+ , "imaginary" ::: 'NotNull 'PGfloat8 ]

111+:}

112+

113+>>> :{

114+let

115+ setup :: Definition (Public '[]) '["public" ::: '["complex" ::: 'Typedef PGcomplex]]

116+ setup = createTypeComposite #complex

117+ (float8 `as` #real :* float8 `as` #imaginary)

118+in printSQL setup

119+:}

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

121+-}

122+createTypeComposite

123+ :: (KnownSymbol ty, Has sch schemas schema, SOP.SListI fields)

124+ => QualifiedAlias sch ty

125+ -- ^ name of the user defined composite type

126+ -> NP (Aliased (TypeExpression schemas)) fields

127+ -- ^ list of attribute names and data types

128+ -> Definition schemas (Alter sch (Create ty ('Typedef ('PGcomposite fields)) schema) schemas)

129+createTypeComposite ty fields = UnsafeDefinition $

130+ "CREATE" <+> "TYPE" <+> renderSQL ty <+> "AS" <+> parenthesized

131+ (renderCommaSeparated renderField fields) <> ";"

132+ where

133+ renderField :: Aliased (TypeExpression schemas) x -> ByteString

134+ renderField (typ `As` alias) =

135+ renderSQL alias <+> renderSQL typ

136+

137+-- | Composite types can also be generated from a Haskell type, for example

138+--

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

140+-- >>> instance SOP.Generic Complex

141+-- >>> instance SOP.HasDatatypeInfo Complex

142+-- >>> type Schema = '["complex" ::: 'Typedef (PG (Composite Complex))]

143+-- >>> :{

144+-- let

145+-- createComplex :: Definition (Public '[]) (Public Schema)

146+-- createComplex = createTypeCompositeFrom @Complex #complex

147+-- in

148+-- printSQL createComplex

149+-- :}

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

151+createTypeCompositeFrom

152+ :: forall hask sch ty schemas schema.

153+ ( SOP.All (FieldTyped schemas) (RowPG hask)

154+ , KnownSymbol ty

155+ , Has sch schemas schema )

156+ => QualifiedAlias sch ty

157+ -- ^ name of the user defined composite type

158+ -> Definition schemas (Alter sch (Create ty ( 'Typedef (PG (Composite hask))) schema) schemas)

159+createTypeCompositeFrom ty = createTypeComposite ty

160+ (SOP.hcpure (SOP.Proxy :: SOP.Proxy (FieldTyped schemas)) fieldtype

161+ :: NP (Aliased (TypeExpression schemas)) (RowPG hask))

162+

163+{-|

164+`createDomain` creates a new domain. A domain is essentially a data type

165+with constraints (restrictions on the allowed set of values).

166+

167+Domains are useful for abstracting common constraints on fields

168+into a single location for maintenance. For example, several tables might

169+contain email address columns, all requiring the same `check` constraint

170+to verify the address syntax. Define a domain rather than setting up

171+each table's constraint individually.

172+

173+>>> :{

174+let

175+ createPositive :: Definition (Public '[]) (Public '["positive" ::: 'Typedef 'PGfloat4])

176+ createPositive = createDomain #positive real (#value .> 0 .&& (#value & isNotNull))

177+in printSQL createPositive

178+:}

179+CREATE DOMAIN "positive" AS real CHECK ((("value" > 0) AND "value" IS NOT NULL));

180+-}

181+createDomain

182+ :: (Has sch schemas schema, KnownSymbol dom)

183+ => QualifiedAlias sch dom

184+ -> (forall null. TypeExpression schemas (null ty))

185+ -> (forall tab. Condition '[] '[] 'Ungrouped schemas '[] '[tab ::: '["value" ::: 'Null ty]])

186+ -> Definition schemas (Alter sch (Create dom ('Typedef ty) schema) schemas)

187+createDomain dom ty condition =

188+ UnsafeDefinition $ "CREATE DOMAIN" <+> renderSQL dom

189+ <+> "AS" <+> renderTypeExpression ty

190+ <+> "CHECK" <+> parenthesized (renderSQL condition) <> ";"

191+

192+{- |

193+>>> :{

194+let

195+ createSmallIntRange :: Definition (Public '[]) (Public '["int2range" ::: 'Typedef ('PGrange 'PGint2)])

196+ createSmallIntRange = createTypeRange #int2range int2

197+in printSQL createSmallIntRange

198+:}

199+CREATE TYPE "int2range" AS RANGE (subtype = int2);

200+-}

201+createTypeRange

202+ :: (Has sch schemas schema, KnownSymbol range)

203+ => QualifiedAlias sch range

204+ -> (forall null. TypeExpression schemas (null ty))

205+ -> Definition schemas (Alter sch (Create range ('Typedef ('PGrange ty)) schema) schemas)

206+createTypeRange range ty = UnsafeDefinition $

207+ "CREATE" <+> "TYPE" <+> renderSQL range <+> "AS" <+> "RANGE" <+>

208+ parenthesized ("subtype" <+> "=" <+> renderTypeExpression ty) <> ";"

209+

210+-- | Drop a type.

211+--

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

213+-- >>> instance SOP.Generic Schwarma

214+-- >>> instance SOP.HasDatatypeInfo Schwarma

215+-- >>> printSQL (dropType #schwarma :: Definition '["public" ::: '["schwarma" ::: 'Typedef (PG (Enumerated Schwarma))]] (Public '[]))

216+-- DROP TYPE "schwarma";

217+dropType

218+ :: (Has sch schemas schema, KnownSymbol td)

219+ => QualifiedAlias sch td

220+ -- ^ name of the user defined type

221+ -> Definition schemas (Alter sch (DropSchemum td 'Typedef schema) schemas)

222+dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderSQL tydef <> ";"

223+

224+dropTypeIfExists

225+ :: (Has sch schemas schema, KnownSymbol td)

226+ => QualifiedAlias sch td

227+ -- ^ name of the user defined type

228+ -> Definition schemas (Alter sch (DropSchemumIfExists td 'Typedef schema) schemas)

229+dropTypeIfExists tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderSQL tydef <> ";"

squeal-postgresql/src/Squeal/PostgreSQL/Definition/View.hsnew file+104

@@ -0,0 +1,104 @@

1+{-|

2+Module: Squeal.PostgreSQL.Definition.View

3+Description: Create and drop view definitions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Create and drop view definitions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveAnyClass

15+ , DeriveGeneric

16+ , DerivingStrategies

17+ , FlexibleContexts

18+ , FlexibleInstances

19+ , GADTs

20+ , LambdaCase

21+ , MultiParamTypeClasses

22+ , OverloadedLabels

23+ , OverloadedStrings

24+ , RankNTypes

25+ , ScopedTypeVariables

26+ , TypeApplications

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableSuperClasses

30+#-}

31+

32+module Squeal.PostgreSQL.Definition.View

33+ ( createView

34+ , createOrReplaceView

35+ , dropView

36+ , dropViewIfExists

37+ ) where

38+

39+import GHC.TypeLits

40+

41+import Squeal.PostgreSQL.Alias

42+import Squeal.PostgreSQL.Definition

43+import Squeal.PostgreSQL.Query

44+import Squeal.PostgreSQL.Render

45+import Squeal.PostgreSQL.Schema

46+

47+-- $setup

48+-- >>> import Squeal.PostgreSQL

49+

50+{- | Create a view.

51+>>> type ABC = '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4]

52+>>> type BC = '["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4]

53+>>> :{

54+let

55+ definition :: Definition

56+ '[ "public" ::: '["abc" ::: 'Table ('[] :=> ABC)]]

57+ '[ "public" ::: '["abc" ::: 'Table ('[] :=> ABC), "bc" ::: 'View BC]]

58+ definition =

59+ createView #bc (select_ (#b :* #c) (from (table #abc)))

60+in printSQL definition

61+:}

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

63+-}

64+createView

65+ :: (Has sch schemas schema, KnownSymbol vw)

66+ => QualifiedAlias sch vw -- ^ the name of the view to add

67+ -> Query '[] '[] schemas '[] view -- ^ query

68+ -> Definition schemas (Alter sch (Create vw ('View view) schema) schemas)

69+createView alias query = UnsafeDefinition $

70+ "CREATE" <+> "VIEW" <+> renderSQL alias <+> "AS"

71+ <+> renderQuery query <> ";"

72+

73+createOrReplaceView

74+ :: (Has sch schemas schema, KnownSymbol vw)

75+ => QualifiedAlias sch vw -- ^ the name of the view to add

76+ -> Query '[] '[] schemas '[] view -- ^ query

77+ -> Definition schemas (Alter sch (CreateOrReplace vw ('View view) schema) schemas)

78+createOrReplaceView alias query = UnsafeDefinition $

79+ "CREATE OR REPLACE VIEW" <+> renderSQL alias <+> "AS"

80+ <+> renderQuery query <> ";"

81+

82+-- | Drop a view.

83+--

84+-- >>> :{

85+-- let

86+-- definition :: Definition

87+-- '[ "public" ::: '["abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])

88+-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]]

89+-- '[ "public" ::: '["abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]]

90+-- definition = dropView #bc

91+-- in printSQL definition

92+-- :}

93+-- DROP VIEW "bc";

94+dropView

95+ :: (Has sch schemas schema, KnownSymbol vw)

96+ => QualifiedAlias sch vw -- ^ view to remove

97+ -> Definition schemas (Alter sch (DropSchemum vw 'View schema) schemas)

98+dropView vw = UnsafeDefinition $ "DROP VIEW" <+> renderSQL vw <> ";"

99+

100+dropViewIfExists

101+ :: (Has sch schemas schema, KnownSymbol vw)

102+ => QualifiedAlias sch vw -- ^ view to remove

103+ -> Definition schemas (Alter sch (DropIfExists vw schema) schemas)

104+dropViewIfExists vw = UnsafeDefinition $ "DROP VIEW IF EXISTS" <+> renderSQL vw <> ";"

squeal-postgresql/src/Squeal/PostgreSQL/Expression.hsnew file+472

@@ -0,0 +1,472 @@

1+{-|

2+Module: Squeal.PostgreSQL.Expression

3+Description: Squeal expressions

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Squeal expressions are the atoms used to build statements.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , DeriveGeneric

15+ , FlexibleContexts

16+ , FlexibleInstances

17+ , FunctionalDependencies

18+ , GADTs

19+ , GeneralizedNewtypeDeriving

20+ , LambdaCase

21+ , MagicHash

22+ , OverloadedStrings

23+ , ScopedTypeVariables

24+ , StandaloneDeriving

25+ , TypeApplications

26+ , TypeFamilies

27+ , TypeInType

28+ , TypeOperators

29+ , UndecidableInstances

30+ , RankNTypes

31+#-}

32+

33+module Squeal.PostgreSQL.Expression

34+ ( -- * Expression

35+ Expression (..)

36+ , Expr

37+ , type (-->)

38+ , FunctionDB

39+ , unsafeFunction

40+ , function

41+ , unsafeLeftOp

42+ , leftOp

43+ , unsafeRightOp

44+ , rightOp

45+ , Operator

46+ , OperatorDB

47+ , unsafeBinaryOp

48+ , binaryOp

49+ , FunctionVar

50+ , unsafeFunctionVar

51+ , type (--->)

52+ , FunctionNDB

53+ , unsafeFunctionN

54+ , functionN

55+ , PGSubset (..)

56+ , PGIntersect (..)

57+ -- * Re-export

58+ , (&)

59+ , K (..)

60+ , unK

61+ ) where

62+

63+import Control.Category

64+import Control.DeepSeq

65+import Data.ByteString (ByteString)

66+import Data.Function ((&))

67+import Data.Semigroup hiding (All)

68+import Data.String

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

70+import GHC.OverloadedLabels

71+import GHC.TypeLits

72+import Numeric

73+import Prelude hiding (id, (.))

74+

75+import qualified GHC.Generics as GHC

76+

77+import Squeal.PostgreSQL.Alias

78+import Squeal.PostgreSQL.List

79+import Squeal.PostgreSQL.Render

80+import Squeal.PostgreSQL.Schema

81+

82+-- $setup

83+-- >>> import Squeal.PostgreSQL

84+

85+{-----------------------------------------

86+column expressions

87+-----------------------------------------}

88+

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

90+such as in the target `Squeal.PostgreSQL.Query.List` of the

91+`Squeal.PostgreSQL.Query.select` command,

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

93+`Squeal.PostgreSQL.Manipulation.update`,

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

95+

96+The expression syntax allows the calculation of

97+values from primitive expression using arithmetic, logical,

98+and 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`.

113+-}

114+newtype Expression

115+ (outer :: FromType)

116+ (commons :: FromType)

117+ (grp :: Grouping)

118+ (schemas :: SchemasType)

119+ (params :: [NullityType])

120+ (from :: FromType)

121+ (ty :: NullityType)

122+ = UnsafeExpression { renderExpression :: ByteString }

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

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

125+ renderSQL = renderExpression

126+

127+-- | An `Expr` is a closed `Expression`.

128+-- It is a F@RankNType@ but don't be scared.

129+-- Think of it as an expression which sees no

130+-- namespaces, so you can't use parameters

131+-- or alias references. It can be used as

132+-- a simple piece of more complex `Expression`s.

133+type Expr x

134+ = forall outer commons grp schemas params from

135+ . Expression outer commons grp schemas params from x

136+ -- ^ cannot reference aliases

137+

138+-- | A @RankNType@ for binary operators.

139+type Operator x1 x2 y

140+ = forall outer commons grp schemas params from

141+ . Expression outer commons grp schemas params from x1

142+ -- ^ left input

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

144+ -- ^ right input

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

146+ -- ^ output

147+

148+type OperatorDB schemas x1 x2 y

149+ = forall outer commons grp params from

150+ . Expression outer commons grp schemas params from x1

151+ -- ^ left input

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

153+ -- ^ right input

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

155+ -- ^ output

156+

157+-- | A @RankNType@ for functions with a single argument.

158+-- These could be either function calls or unary operators.

159+-- This is a subtype of the usual Haskell function type `Prelude.->`,

160+-- indeed a subcategory as it is closed under the usual

161+-- `Prelude..` and `Prelude.id`.

162+type (-->) x y

163+ = forall outer commons grp schemas params from

164+ . Expression outer commons grp schemas params from x

165+ -- ^ input

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

167+ -- ^ output

168+

169+type FunctionDB schemas x y

170+ = forall outer commons grp params from

171+ . Expression outer commons grp schemas params from x

172+ -- ^ input

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

174+ -- ^ output

175+

176+{- | A @RankNType@ for functions with a fixed-length list of heterogeneous arguments.

177+Use the `*:` operator to end your argument lists, like so.

178+

179+>>> printSQL (unsafeFunctionN "fun" (true :* false :* localTime *: true))

180+fun(TRUE, FALSE, LOCALTIME, TRUE)

181+-}

182+type (--->) xs y

183+ = forall outer commons grp schemas params from

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

185+ -- ^ inputs

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

187+ -- ^ output

188+

189+type FunctionNDB schemas xs y

190+ = forall outer commons grp params from

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

192+ -- ^ inputs

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

194+ -- ^ output

195+

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

197+homogeneous arguments and at least 1 more argument.

198+-}

199+type FunctionVar x0 x1 y

200+ = forall outer commons grp schemas params from

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

202+ -- ^ inputs

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

204+ -- ^ must have at least 1 input

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

206+ -- ^ output

207+

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

209+greatest(TRUE, NULL, FALSE)

210+-}

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

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

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

214+

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

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

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

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

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

220+ fromLabel = fromLabel @col :* Nil

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

222+ => IsLabel col

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

224+ fromLabel = fromLabel @col `As` Alias

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

226+ => IsLabel col

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

228+ fromLabel = fromLabel @col :* Nil

229+

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

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

232+ tab ! col = UnsafeExpression $

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

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

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

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

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

238+ => IsQualified tab col

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

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

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

242+ => IsQualified tab col

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

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

245+

246+instance

247+ ( HasUnique tab (Join outer from) row

248+ , Has col row ty

249+ , GroupedBy tab col bys

250+ ) => IsLabel col

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

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

253+instance

254+ ( HasUnique tab (Join outer from) row

255+ , Has col row ty

256+ , GroupedBy tab col bys

257+ , tys ~ '[ty]

258+ ) => IsLabel col

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

260+ fromLabel = fromLabel @col :* Nil

261+instance

262+ ( HasUnique tab (Join outer from) row

263+ , Has col row ty

264+ , GroupedBy tab col bys

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

266+ ) => IsLabel col

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

268+ fromLabel = fromLabel @col `As` Alias

269+instance

270+ ( HasUnique tab (Join outer from) row

271+ , Has col row ty

272+ , GroupedBy tab col bys

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

274+ ) => IsLabel col

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

276+ fromLabel = fromLabel @col :* Nil

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+

315+-- | >>> printSQL $ unsafeBinaryOp "OR" true false

316+-- (TRUE OR FALSE)

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

318+unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

319+ renderSQL x <+> op <+> renderSQL y

320+

321+binaryOp

322+ :: forall op sch schemas schema x y z.

323+ ( Has sch schemas schema

324+ , Has op schema ('Operator ('BinaryOp x y z)) )

325+ => OperatorDB schemas x y z

326+binaryOp = unsafeBinaryOp $ renderSymbol @op

327+

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

329+-- (NOT TRUE)

330+unsafeLeftOp :: ByteString -> x --> y

331+unsafeLeftOp op x = UnsafeExpression $ parenthesized $ op <+> renderSQL x

332+

333+leftOp

334+ :: forall op sch schemas schema x y.

335+ ( Has sch schemas schema

336+ , Has op schema ('Operator ('LeftOp x y)) )

337+ => FunctionDB schemas x y

338+leftOp = unsafeLeftOp $ renderSymbol @op

339+

340+-- | >>> printSQL $ true & unsafeRightOp "IS NOT TRUE"

341+-- (TRUE IS NOT TRUE)

342+unsafeRightOp :: ByteString -> x --> y

343+unsafeRightOp op x = UnsafeExpression $ parenthesized $ renderSQL x <+> op

344+

345+rightOp

346+ :: forall op sch schemas schema x y.

347+ ( Has sch schemas schema

348+ , Has op schema ('Operator ('RightOp x y)) )

349+ => FunctionDB schemas x y

350+rightOp = unsafeRightOp $ renderSymbol @op

351+

352+-- | >>> printSQL $ unsafeFunction "f" true

353+-- f(TRUE)

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

355+unsafeFunction fun x = UnsafeExpression $

356+ fun <> parenthesized (renderSQL x)

357+

358+function

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

360+ => QualifiedAlias sch fun

361+ -> FunctionDB schemas x y

362+function = unsafeFunction . renderSQL

363+

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

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

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

367+unsafeFunctionN fun xs = UnsafeExpression $

368+ fun <> parenthesized (renderCommaSeparated renderSQL xs)

369+

370+functionN

371+ :: ( Has sch schemas schema

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

373+ , SListI xs )

374+ => QualifiedAlias sch fun

375+ -> FunctionNDB schemas xs y

376+functionN = unsafeFunctionN . renderSQL

377+

378+instance ty `In` PGNum

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

380+ (+) = unsafeBinaryOp "+"

381+ (-) = unsafeBinaryOp "-"

382+ (*) = unsafeBinaryOp "*"

383+ abs = unsafeFunction "abs"

384+ signum = unsafeFunction "sign"

385+ fromInteger

386+ = UnsafeExpression

387+ . fromString

388+ . show

389+

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

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

392+ (/) = unsafeBinaryOp "/"

393+ fromRational

394+ = UnsafeExpression

395+ . fromString

396+ . ($ "")

397+ . showFFloat Nothing

398+ . fromRat @Double

399+

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

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

402+ pi = UnsafeExpression "pi()"

403+ exp = unsafeFunction "exp"

404+ log = unsafeFunction "ln"

405+ sqrt = unsafeFunction "sqrt"

406+ b ** x = UnsafeExpression $

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

408+ logBase b y = log y / log b

409+ sin = unsafeFunction "sin"

410+ cos = unsafeFunction "cos"

411+ tan = unsafeFunction "tan"

412+ asin = unsafeFunction "asin"

413+ acos = unsafeFunction "acos"

414+ atan = unsafeFunction "atan"

415+ sinh x = (exp x - exp (-x)) / 2

416+ cosh x = (exp x + exp (-x)) / 2

417+ tanh x = sinh x / cosh x

418+ asinh x = log (x + sqrt (x*x + 1))

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

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

421+

422+-- | Contained by operators

423+class PGSubset ty where

424+ (@>) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

425+ (@>) = unsafeBinaryOp "@>"

426+ (<@) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

427+ (<@) = unsafeBinaryOp "<@"

428+instance PGSubset 'PGjsonb

429+instance PGSubset 'PGtsquery

430+instance PGSubset ('PGvararray ty)

431+instance PGSubset ('PGrange ty)

432+

433+class PGIntersect ty where

434+ (@&&) :: Operator (null0 ty) (null1 ty) ('Null 'PGbool)

435+ (@&&) = unsafeBinaryOp "&&"

436+instance PGIntersect ('PGvararray ty)

437+instance PGIntersect ('PGrange ty)

438+

439+instance IsString

440+ (Expression outer commons grp schemas params from (null 'PGtext)) where

441+ fromString str = UnsafeExpression $

442+ "E\'" <> fromString (escape =<< str) <> "\'"

443+instance IsString

444+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

445+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsvector") $

446+ "E\'" <> fromString (escape =<< str) <> "\'"

447+instance IsString

448+ (Expression outer commons grp schemas params from (null 'PGtsquery)) where

449+ fromString str = UnsafeExpression . parenthesized . (<> " :: tsquery") $

450+ "E\'" <> fromString (escape =<< str) <> "\'"

451+

452+instance Semigroup

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 "||"

464+

465+instance Monoid

466+ (Expression outer commons grp schemas params from (null 'PGtext)) where

467+ mempty = fromString ""

468+ mappend = (<>)

469+instance Monoid

470+ (Expression outer commons grp schemas params from (null 'PGtsvector)) where

471+ mempty = fromString ""

472+ mappend = (<>)

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.hsnew file+578

@@ -0,0 +1,578 @@

1+{-|

2+Module: Squeal.PostgreSQL.Manipulation

3+Description: Squeal data manipulation language

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Squeal data manipulation language.

9+-}

10+

11+{-# LANGUAGE

12+ DeriveGeneric

13+ , FlexibleContexts

14+ , FlexibleInstances

15+ , GADTs

16+ , GeneralizedNewtypeDeriving

17+ , LambdaCase

18+ , MultiParamTypeClasses

19+ , OverloadedStrings

20+ , PatternSynonyms

21+ , QuantifiedConstraints

22+ , RankNTypes

23+ , ScopedTypeVariables

24+ , TypeApplications

25+ , TypeFamilies

26+ , TypeInType

27+ , TypeOperators

28+ , UndecidableInstances

29+#-}

30+

31+module Squeal.PostgreSQL.Manipulation

32+ ( -- * Manipulation

33+ Manipulation_

34+ , Manipulation (..)

35+ , queryStatement

36+ -- * Insert

37+ , insertInto

38+ , insertInto_

39+ -- * Update

40+ , update

41+ , update_

42+ -- * Delete

43+ , deleteFrom

44+ , deleteFrom_

45+ -- * Clauses

46+ , Optional (..)

47+ , QueryClause (..)

48+ , pattern Values_

49+ , ReturningClause (..)

50+ , pattern Returning_

51+ , ConflictClause (..)

52+ , ConflictTarget (..)

53+ , ConflictAction (..)

54+ , UsingClause (..)

55+ ) where

56+

57+import Control.DeepSeq

58+import Data.ByteString hiding (foldr)

59+import Data.Kind (Type)

60+

61+import qualified Generics.SOP as SOP

62+import qualified GHC.Generics as GHC

63+

64+import Squeal.PostgreSQL.Alias

65+import Squeal.PostgreSQL.Expression

66+import Squeal.PostgreSQL.Expression.Logic

67+import Squeal.PostgreSQL.List

68+import Squeal.PostgreSQL.PG

69+import Squeal.PostgreSQL.Render

70+import Squeal.PostgreSQL.Query

71+import Squeal.PostgreSQL.Schema

72+

73+-- $setup

74+-- >>> import Squeal.PostgreSQL

75+-- >>> import Data.Int

76+-- >>> import Data.Time

77+

78+{- |

79+A `Manipulation` is a statement which may modify data in the database,

80+but does not alter its schemas. Examples are inserts, updates and deletes.

81+A `Query` is also considered a `Manipulation` even though it does not modify data.

82+

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+

125+simple insert:

126+

127+>>> type Columns = '["col1" ::: 'NoDef :=> 'Null 'PGint4, "col2" ::: 'Def :=> 'NotNull 'PGint4]

128+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

129+>>> :{

130+let

131+ manipulation :: Manipulation_ (Public Schema) () ()

132+ manipulation =

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

134+in printSQL manipulation

135+:}

136+INSERT INTO "tab" ("col1", "col2") VALUES (2, DEFAULT)

137+

138+parameterized insert:

139+

140+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

141+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

142+>>> :{

143+let

144+ manipulation :: Manipulation_ (Public Schema) (Int32, Int32) ()

145+ manipulation =

146+ insertInto_ #tab (Values_ (Set (param @1) `as` #col1 :* Set (param @2) `as` #col2))

147+in printSQL manipulation

148+:}

149+INSERT INTO "tab" ("col1", "col2") VALUES (($1 :: int4), ($2 :: int4))

150+

151+returning insert:

152+

153+>>> :{

154+let

155+ manipulation :: Manipulation_ (Public Schema) () (Only Int32)

156+ manipulation =

157+ insertInto #tab (Values_ (Set 2 `as` #col1 :* Set 3 `as` #col2))

158+ OnConflictDoRaise (Returning (#col1 `as` #fromOnly))

159+in printSQL manipulation

160+:}

161+INSERT INTO "tab" ("col1", "col2") VALUES (2, 3) RETURNING "col1" AS "fromOnly"

162+

163+upsert:

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)]

168+>>> :{

169+let

170+ manipulation :: Manipulation_ (Public CustomersSchema) () ()

171+ manipulation =

172+ insertInto #customers

173+ (Values_ (Set "John Smith" `as` #name :* Set "john@smith.com" `as` #email))

174+ (OnConflict (OnConstraint #uq)

175+ (DoUpdate (Set (#excluded ! #email <> "; " <> #customers ! #email) `as` #email) []))

176+ (Returning_ Nil)

177+in printSQL manipulation

178+:}

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"))

180+

181+query insert:

182+

183+>>> :{

184+let

185+ manipulation :: Manipulation_ (Public Schema) () ()

186+ manipulation = insertInto_ #tab (Subquery (select Star (from (table #tab))))

187+in printSQL manipulation

188+:}

189+INSERT INTO "tab" SELECT * FROM "tab" AS "tab"

190+

191+update:

192+

193+>>> :{

194+let

195+ manipulation :: Manipulation_ (Public Schema) () ()

196+ manipulation = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)

197+in printSQL manipulation

198+:}

199+UPDATE "tab" SET "col1" = 2 WHERE ("col1" <> "col2")

200+

201+delete:

202+

203+>>> :{

204+let

205+ manipulation :: Manipulation_ (Public Schema) () (Row Int32 Int32)

206+ manipulation = deleteFrom #tab NoUsing (#col1 .== #col2) (Returning Star)

207+in printSQL manipulation

208+:}

209+DELETE FROM "tab" WHERE ("col1" = "col2") RETURNING *

210+

211+delete and using clause:

212+

213+>>> :{

214+type Schema3 =

215+ '[ "tab" ::: 'Table ('[] :=> Columns)

216+ , "other_tab" ::: 'Table ('[] :=> Columns)

217+ , "third_tab" ::: 'Table ('[] :=> Columns) ]

218+:}

219+

220+>>> :{

221+let

222+ manipulation :: Manipulation_ (Public Schema3) () ()

223+ manipulation =

224+ deleteFrom #tab (Using (table #other_tab & also (table #third_tab)))

225+ ( (#tab ! #col2 .== #other_tab ! #col2)

226+ .&& (#tab ! #col2 .== #third_tab ! #col2) )

227+ (Returning_ Nil)

228+in printSQL manipulation

229+:}

230+DELETE FROM "tab" USING "other_tab" AS "other_tab", "third_tab" AS "third_tab" WHERE (("tab"."col2" = "other_tab"."col2") AND ("tab"."col2" = "third_tab"."col2"))

231+

232+with manipulation:

233+

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

235+>>> type ProductsSchema = '["products" ::: 'Table ('[] :=> ProductsColumns), "products_deleted" ::: 'Table ('[] :=> ProductsColumns)]

236+>>> :{

237+let

238+ manipulation :: Manipulation_ (Public ProductsSchema) (Only Day) ()

239+ manipulation = with

240+ (deleteFrom #products NoUsing (#date .< param @1) (Returning Star) `as` #del)

241+ (insertInto_ #products_deleted (Subquery (select Star (from (common #del)))))

242+in printSQL manipulation

243+:}

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

245+-}

246+type family Manipulation_ (schemas :: SchemasType) (params :: Type) (row :: Type) where

247+ Manipulation_ schemas params row = Manipulation '[] schemas (TuplePG params) (RowPG row)

248+

249+-- | Convert a `Query` into a `Manipulation`.

250+queryStatement

251+ :: Query '[] commons schemas params columns

252+ -- ^ `Query` to embed as a `Manipulation`

253+ -> Manipulation commons schemas params columns

254+queryStatement q = UnsafeManipulation $ renderSQL q

255+

256+{-----------------------------------------

257+INSERT statements

258+-----------------------------------------}

259+

260+{- |

261+When a table is created, it contains no data. The first thing to do

262+before a database can be of much use is to insert data. Data is

263+conceptually inserted one row at a time. Of course you can also insert

264+more than one row, but there is no way to insert less than one row.

265+Even if you know only some column values, a complete row must be created.

266+-}

267+insertInto

268+ :: ( Has sch schemas schema

269+ , Has tab schema ('Table 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

277+ -- ^ what to insert

278+ -> ConflictClause tab commons schemas params table

279+ -- ^ what to do in case of conflict

280+ -> ReturningClause commons schemas params '[tab ::: row0] row1

281+ -- ^ what to return

282+ -> Manipulation commons schemas params row1

283+insertInto tab qry conflict ret = UnsafeManipulation $

284+ "INSERT" <+> "INTO" <+> renderSQL tab

285+ <+> renderSQL qry

286+ <> renderSQL conflict

287+ <> renderSQL ret

288+

289+-- | Like `insertInto` but with `OnConflictDoRaise` and `no` `ReturningClause`.

290+insertInto_

291+ :: ( Has sch schemas schema

292+ , Has tab schema ('Table table)

293+ , columns ~ TableToColumns table

294+ , row ~ TableToRow table

295+ , SOP.SListI columns )

296+ => QualifiedAlias sch tab

297+ -- ^ table

298+ -> QueryClause commons schemas params columns

299+ -- ^ what to insert

300+ -> Manipulation commons schemas params '[]

301+insertInto_ tab qry =

302+ insertInto tab qry OnConflictDoRaise (Returning_ Nil)

303+

304+-- | A `QueryClause` describes what to `insertInto` a table.

305+data QueryClause commons schemas params columns where

306+ Values

307+ :: SOP.SListI columns

308+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

309+ -- ^ row of values

310+ -> [NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns]

311+ -- ^ additional rows of values

312+ -> QueryClause commons schemas params columns

313+ Select

314+ :: SOP.SListI columns

315+ => NP (Aliased (Optional (Expression '[] commons grp schemas params from))) columns

316+ -- ^ row of values

317+ -> TableExpression '[] commons grp schemas params from

318+ -- ^ from a table expression

319+ -> QueryClause commons schemas params columns

320+ Subquery

321+ :: ColumnsToRow columns ~ row

322+ => Query '[] commons schemas params row

323+ -- ^ subquery to insert

324+ -> QueryClause commons schemas params columns

325+

326+instance RenderSQL (QueryClause commons schemas params columns) where

327+ renderSQL = \case

328+ Values row0 rows ->

329+ parenthesized (renderCommaSeparated renderSQLPart row0)

330+ <+> "VALUES"

331+ <+> commaSeparated

332+ ( parenthesized

333+ . renderCommaSeparated renderValuePart <$> row0 : rows )

334+ Select row0 tab ->

335+ parenthesized (renderCommaSeparatedMaybe renderSQLPartMaybe row0)

336+ <+> "SELECT"

337+ <+> renderCommaSeparatedMaybe renderValuePartMaybe row0

338+ <+> renderSQL tab

339+ Subquery qry -> renderQuery qry

340+ where

341+ renderSQLPartMaybe, renderValuePartMaybe

342+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

343+ -> Maybe ByteString

344+ renderSQLPartMaybe = \case

345+ Default `As` _ -> Nothing

346+ Set _ `As` name -> Just $ renderSQL name

347+ renderValuePartMaybe = \case

348+ Default `As` _ -> Nothing

349+ Set value `As` _ -> Just $ renderExpression value

350+ renderSQLPart, renderValuePart

351+ :: Aliased (Optional (Expression '[] commons grp schemas params from)) column

352+ -> ByteString

353+ renderSQLPart (_ `As` name) = renderSQL name

354+ renderValuePart (value `As` _) = renderSQL value

355+

356+-- | `Values_` describes a single `NP` list of `Aliased` `Optional` `Expression`s

357+-- whose `ColumnsType` must match the tables'.

358+pattern Values_

359+ :: SOP.SListI columns

360+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[]))) columns

361+ -- ^ row of values

362+ -> QueryClause commons schemas params columns

363+pattern Values_ vals = Values vals []

364+

365+-- | `Optional` is either `Default` or a value, parameterized by an appropriate

366+-- `ColumnConstraint`.

367+data Optional expr ty where

368+ -- | Use the `Default` value for a column.

369+ Default :: Optional expr ('Def :=> ty)

370+ -- | `Set` a value for a column.

371+ Set :: expr ty -> Optional expr (def :=> ty)

372+

373+instance (forall x. RenderSQL (expr x)) => RenderSQL (Optional expr ty) where

374+ renderSQL = \case

375+ Default -> "DEFAULT"

376+ Set expr -> renderSQL expr

377+

378+-- | A `ReturningClause` computes and return value(s) based

379+-- on each row actually inserted, updated or deleted. This is primarily

380+-- useful for obtaining values that were supplied by defaults, such as a

381+-- serial sequence number. However, any expression using the table's columns

382+-- is allowed. Only rows that were successfully inserted or updated or

383+-- deleted will be returned. For example, if a row was locked

384+-- but not updated because an `OnConflict` `DoUpdate` condition was not satisfied,

385+-- the row will not be returned. `Returning` `Star` will return all columns

386+-- in the row. Use `Returning` `Nil` in the common case where no return

387+-- values are desired.

388+newtype ReturningClause commons schemas params from row =

389+ Returning (Selection '[] commons 'Ungrouped schemas params from row)

390+

391+instance RenderSQL (ReturningClause commons schemas params from row) where

392+ renderSQL = \case

393+ Returning (List Nil) -> ""

394+ Returning selection -> " RETURNING" <+> renderSQL selection

395+

396+-- | `Returning` a `List`

397+pattern Returning_

398+ :: SOP.SListI row

399+ => NP (Aliased (Expression '[] commons 'Ungrouped schemas params from)) row

400+ -- ^ row of values

401+ -> ReturningClause commons schemas params from row

402+pattern Returning_ list = Returning (List list)

403+

404+-- | A `ConflictClause` specifies an action to perform upon a constraint

405+-- violation. `OnConflictDoRaise` will raise an error.

406+-- `OnConflict` `DoNothing` simply avoids inserting a row.

407+-- `OnConflict` `DoUpdate` updates the existing row that conflicts with the row

408+-- proposed for insertion.

409+data ConflictClause tab commons schemas params table where

410+ OnConflictDoRaise :: ConflictClause tab commons schemas params table

411+ OnConflict

412+ :: ConflictTarget constraints

413+ -- ^ conflict target

414+ -> ConflictAction tab commons schemas params columns

415+ -- ^ conflict action

416+ -> ConflictClause tab commons schemas params (constraints :=> columns)

417+

418+-- | Render a `ConflictClause`.

419+instance SOP.SListI (TableToColumns table)

420+ => RenderSQL (ConflictClause tab commons schemas params table) where

421+ renderSQL = \case

422+ OnConflictDoRaise -> ""

423+ OnConflict target action -> " ON CONFLICT"

424+ <+> renderSQL target <+> renderSQL action

425+

426+{- |

427+`ConflictAction` specifies an alternative `OnConflict` action.

428+It can be either `DoNothing`, or a `DoUpdate` clause specifying

429+the exact details of the `update` action to be performed in case of a conflict.

430+The `Set` and WHERE `Condition`s in `OnConflict` `DoUpdate` have access to the

431+existing row using the table's name (or an alias), and to rows proposed

432+for insertion using the special @#excluded@ table.

433+`OnConflict` `DoNothing` simply avoids inserting a row as its alternative action.

434+`OnConflict` `DoUpdate` updates the existing row that conflicts

435+with the row proposed for insertion as its alternative action.

436+-}

437+data ConflictAction tab commons schemas params columns where

438+ DoNothing :: ConflictAction tab commons schemas params columns

439+ DoUpdate

440+ :: ( row ~ ColumnsToRow columns

441+ , SOP.SListI columns

442+ , columns ~ (col0 ': cols)

443+ , SOP.All (HasIn columns) subcolumns

444+ , AllUnique subcolumns )

445+ => NP (Aliased (Optional (Expression '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]))) subcolumns

446+ -> [Condition '[] commons 'Ungrouped schemas params '[tab ::: row, "excluded" ::: row]]

447+ -- ^ WHERE `Condition`s

448+ -> ConflictAction tab commons schemas params columns

449+

450+instance RenderSQL (ConflictAction tab commons schemas params columns) where

451+ renderSQL = \case

452+ DoNothing -> "DO NOTHING"

453+ DoUpdate updates whs'

454+ -> "DO UPDATE SET"

455+ <+> renderCommaSeparated renderUpdate updates

456+ <> case whs' of

457+ [] -> ""

458+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

459+

460+renderUpdate

461+ :: (forall x. RenderSQL (expr x))

462+ => Aliased (Optional expr) ty

463+ -> ByteString

464+renderUpdate (expr `As` col) = renderSQL col <+> "=" <+> renderSQL expr

465+

466+-- | A `ConflictTarget` specifies the constraint violation that triggers a

467+-- `ConflictAction`.

468+data ConflictTarget constraints where

469+ OnConstraint

470+ :: Has con constraints constraint

471+ => Alias con

472+ -> ConflictTarget constraints

473+

474+-- | Render a `ConflictTarget`

475+instance RenderSQL (ConflictTarget constraints) where

476+ renderSQL (OnConstraint con) =

477+ "ON" <+> "CONSTRAINT" <+> renderSQL con

478+

479+{-----------------------------------------

480+UPDATE statements

481+-----------------------------------------}

482+

483+-- | An `update` command changes the values of the specified columns

484+-- in all rows that satisfy the condition.

485+update

486+ :: ( SOP.SListI columns

487+ , SOP.SListI row1

488+ , Has sch schemas schema

489+ , Has tab schema ('Table table)

490+ , row0 ~ TableToRow table

491+ , columns ~ TableToColumns table

492+ , SOP.All (HasIn columns) subcolumns

493+ , AllUnique subcolumns )

494+ => QualifiedAlias sch tab -- ^ table to update

495+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row0]))) subcolumns

496+ -- ^ modified values to replace old values

497+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row0]

498+ -- ^ condition under which to perform update on a row

499+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

500+ -> Manipulation commons schemas params row1

501+update tab columns wh returning = UnsafeManipulation $

502+ "UPDATE"

503+ <+> renderSQL tab

504+ <+> "SET"

505+ <+> renderCommaSeparated renderUpdate columns

506+ <+> "WHERE" <+> renderSQL wh

507+ <> renderSQL returning

508+

509+-- | Update a row returning `Nil`.

510+update_

511+ :: ( SOP.SListI columns

512+ , Has sch schemas schema

513+ , Has tab schema ('Table table)

514+ , row ~ TableToRow table

515+ , columns ~ TableToColumns table

516+ , SOP.All (HasIn columns) subcolumns

517+ , AllUnique subcolumns )

518+ => QualifiedAlias sch tab -- ^ table to update

519+ -> NP (Aliased (Optional (Expression '[] '[] 'Ungrouped schemas params '[tab ::: row]))) subcolumns

520+ -- ^ modified values to replace old values

521+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

522+ -- ^ condition under which to perform update on a row

523+ -> Manipulation commons schemas params '[]

524+update_ tab columns wh = update tab columns wh (Returning_ Nil)

525+

526+{-----------------------------------------

527+DELETE statements

528+-----------------------------------------}

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+

546+-- | Delete rows from a table.

547+deleteFrom

548+ :: ( SOP.SListI row1

549+ , Has sch schemas schema

550+ , Has tab schema ('Table table)

551+ , row0 ~ TableToRow table

552+ , columns ~ TableToColumns table )

553+ => QualifiedAlias sch tab -- ^ table to delete from

554+ -> UsingClause commons schemas params from

555+ -> Condition '[] commons 'Ungrouped schemas params (tab ::: row0 ': from)

556+ -- ^ condition under which to delete a row

557+ -> ReturningClause commons schemas params '[tab ::: row0] row1 -- ^ results to return

558+ -> Manipulation commons schemas params row1

559+deleteFrom tab using wh returning = UnsafeManipulation $

560+ "DELETE FROM"

561+ <+> renderSQL tab

562+ <> case using of

563+ NoUsing -> ""

564+ Using tables -> " USING" <+> renderSQL tables

565+ <+> "WHERE" <+> renderSQL wh

566+ <> renderSQL returning

567+

568+-- | Delete rows returning `Nil`.

569+deleteFrom_

570+ :: ( Has sch schemas schema

571+ , Has tab schema ('Table table)

572+ , row ~ TableToRow table

573+ , columns ~ TableToColumns table )

574+ => QualifiedAlias sch tab -- ^ table to delete from

575+ -> Condition '[] commons 'Ungrouped schemas params '[tab ::: row]

576+ -- ^ condition under which to delete a row

577+ -> Manipulation commons schemas params '[]

578+deleteFrom_ tab wh = deleteFrom tab NoUsing wh (Returning_ Nil)

squeal-postgresql/src/Squeal/PostgreSQL/Migration.hsnew file+448

@@ -0,0 +1,448 @@

1+{-|

2+Module: Squeal.PostgreSQL.Migration

3+Description: Squeal migrations

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+This module defines a `Migration` type to safely

9+change the schema of your database over time. Let's see an example!

10+

11+First turn on some extensions.

12+

13+>>> :set -XDataKinds -XOverloadedLabels

14+>>> :set -XOverloadedStrings -XFlexibleContexts -XTypeOperators

15+

16+Next, let's define our `TableType`s.

17+

18+>>> :{

19+type UsersTable =

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

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

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

23+ ]

24+:}

25+

26+>>> :{

27+type EmailsTable =

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

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

30+ ] :=>

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

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

33+ , "email" ::: 'NoDef :=> 'Null 'PGtext

34+ ]

35+:}

36+

37+Now we can define some `Migration`s to make our tables.

38+

39+>>> :{

40+let

41+ makeUsers :: Migration Definition (Public '[]) '["public" ::: '["users" ::: 'Table UsersTable]]

42+ makeUsers = Migration

43+ { name = "make users table"

44+ , up = createTable #users

45+ ( serial `as` #id :*

46+ notNullable text `as` #name )

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

48+ , down = dropTable #users

49+ }

50+:}

51+

52+>>> :{

53+let

54+ makeEmails :: Migration Definition '["public" ::: '["users" ::: 'Table UsersTable]]

55+ '["public" ::: '["users" ::: 'Table UsersTable, "emails" ::: 'Table EmailsTable]]

56+ makeEmails = Migration

57+ { name = "make emails table"

58+ , up = createTable #emails

59+ ( serial `as` #id :*

60+ notNullable int `as` #user_id :*

61+ nullable text `as` #email )

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

63+ foreignKey #user_id #users #id

64+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )

65+ , down = dropTable #emails

66+ }

67+:}

68+

69+Now that we have a couple migrations we can chain them together into a `Path`.

70+

71+>>> let migrations = makeUsers :>> makeEmails :>> Done

72+

73+Now run the migrations.

74+

75+>>> import Control.Monad.IO.Class

76+>>> :{

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

78+ manipulate (UnsafeManipulation "SET client_min_messages TO WARNING;")

79+ -- suppress notices

80+ & pqThen (liftIO (putStrLn "Migrate"))

81+ & pqThen (migrateUp migrations)

82+ & pqThen (liftIO (putStrLn "Rollback"))

83+ & pqThen (migrateDown migrations)

84+:}

85+Migrate

86+Rollback

87+

88+We can also create a simple executable using `defaultMain`.

89+

90+>>> let main = defaultMain "host=localhost port=5432 dbname=exampledb" migrations

91+

92+>>> withArgs [] main

93+Invalid command: "". Use:

94+migrate to run all available migrations

95+rollback to rollback all available migrations

96+status to display migrations run and migrations left to run

97+

98+>>> withArgs ["status"] main

99+Migrations already run:

100+ None

101+Migrations left to run:

102+ - make users table

103+ - make emails table

104+

105+>>> withArgs ["migrate"] main

106+Migrations already run:

107+ - make users table

108+ - make emails table

109+Migrations left to run:

110+ None

111+

112+>>> withArgs ["rollback"] main

113+Migrations already run:

114+ None

115+Migrations left to run:

116+ - make users table

117+ - make emails table

118+

119+In addition to enabling `Migration`s using pure SQL `Definition`s for

120+the `up` and `down` instructions, you can also perform impure `IO` actions

121+by using a `Migration`s over the `Terminally` `PQ` `IO` category.

122+-}

123+

124+{-# LANGUAGE

125+ DataKinds

126+ , DeriveGeneric

127+ , FlexibleContexts

128+ , FlexibleInstances

129+ , GADTs

130+ , LambdaCase

131+ , OverloadedLabels

132+ , OverloadedStrings

133+ , PolyKinds

134+ , QuantifiedConstraints

135+ , RankNTypes

136+ , TypeApplications

137+ , TypeOperators

138+#-}

139+

140+module Squeal.PostgreSQL.Migration

141+ ( -- * Migration

142+ Migration (..)

143+ , Migratory (..)

144+ , Terminally (..)

145+ , terminally

146+ , pureMigration

147+ , MigrationsTable

148+ , defaultMain

149+ ) where

150+

151+import Control.Category

152+import Control.Monad

153+import Data.ByteString (ByteString)

154+import Data.Foldable (traverse_)

155+import Data.Function ((&))

156+import Data.List ((\\))

157+import Data.Text (Text)

158+import Data.Time (UTCTime)

159+import Prelude hiding ((.), id)

160+import System.Environment

161+import UnliftIO (MonadIO (..))

162+

163+import qualified Data.Text.IO as Text (putStrLn)

164+import qualified Generics.SOP as SOP

165+import qualified GHC.Generics as GHC

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.

184+-- It should contain an inverse pair of `up` and `down`

185+-- instructions and a unique `name`.

186+data Migration p schemas0 schemas1 = Migration

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

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

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

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

191+ } deriving (GHC.Generic)

192+

193+{- |

194+A `Migratory` @p@ is a `Category` for which one can execute or rewind

195+a `Path` of `Migration`s over @p@. This includes the category of pure

196+SQL `Definition`s and the category of impure `Terminally` `PQ` `IO` actions.

197+-}

198+class Category p => Migratory p where

199+

200+ {- |

201+ Run a `Path` of `Migration`s.

202+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

203+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

204+ if not, `up` the `Migration` and insert its `name` in the `MigrationsTable`.

205+ -}

206+ migrateUp

207+ :: Path (Migration p) schemas0 schemas1

208+ -> PQ schemas0 schemas1 IO ()

209+

210+ {- |

211+ Rewind a `Path` of `Migration`s.

212+ Create the `MigrationsTable` as @public.schema_migrations@ if it does not already exist.

213+ In one transaction, for each each `Migration` query to see if the `Migration` has been executed;

214+ if so, `down` the `Migration` and delete its `name` in the `MigrationsTable`.

215+ -}

216+ migrateDown

217+ :: Path (Migration p) schemas0 schemas1

218+ -> PQ schemas1 schemas0 IO ()

219+

220+instance Migratory Definition where

221+ migrateUp = migrateUp . cmap pureMigration

222+ migrateDown = migrateDown . cmap pureMigration

223+

224+{- | `Terminally` turns an indexed monad transformer and the monad it transforms

225+into a category by restricting the return type to @()@ and permuting the type variables.

226+This is similar to how applying a monad to @()@ yields a monoid.

227+Since a `Terminally` action has a trivial return value, the only reason

228+to run one is for the side effects, in particular database and other IO effects.

229+-}

230+newtype Terminally trans monad x0 x1 = Terminally

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

232+ deriving GHC.Generic

233+

234+instance

235+ ( IndexedMonadTransPQ trans

236+ , Monad monad

237+ , forall x0 x1. x0 ~ x1 => Monad (trans x0 x1 monad) )

238+ => Category (Terminally trans monad) where

239+ id = Terminally (return ())

240+ Terminally g . Terminally f = Terminally $ pqThen g f

241+

242+-- | `terminally` ignores the output of a computation, returning @()@ and

243+-- wrapping it up into a `Terminally`. You can lift an action in the base monad

244+-- by using @terminally . lift@.

245+terminally

246+ :: Functor (trans x0 x1 monad)

247+ => trans x0 x1 monad ignore

248+ -> Terminally trans monad x0 x1

249+terminally = Terminally . void

250+

251+-- | A `pureMigration` turns a `Migration` involving only pure SQL

252+-- `Definition`s into a `Migration` that may be combined with arbitrary `IO`.

253+pureMigration

254+ :: Migration Definition schemas0 schemas1

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

256+pureMigration migration = Migration

257+ { name = name migration

258+ , up = terminally . define $ up migration

259+ , down = terminally . define $ down migration

260+ }

261+

262+instance Migratory (Terminally PQ IO) where

263+

264+ migrateUp migration = unsafePQ . transactionally_ $ do

265+ define createMigrations

266+ upMigrations migration

267+

268+ where

269+

270+ upMigrations

271+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

272+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

273+ upMigrations = \case

274+ Done -> return ()

275+ step :>> steps -> upMigration step >> upMigrations steps

276+

277+ upMigration

278+ :: Migration (Terminally PQ IO) schemas0 schemas1

279+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

280+ upMigration step = do

281+ executed <- queryExecuted step

282+ unless (executed == 1) $ do

283+ unsafePQ . runTerminally $ up step

284+ manipulateParams_ insertMigration (Only (name step))

285+

286+ queryExecuted

287+ :: Migration (Terminally PQ IO) schemas0 schemas1

288+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

289+ queryExecuted step = do

290+ result <- runQueryParams selectMigration (Only (name step))

291+ ntuples result

292+

293+ migrateDown migrations = unsafePQ . transactionally_ $ do

294+ define createMigrations

295+ downMigrations migrations

296+

297+ where

298+

299+ downMigrations

300+ :: Path (Migration (Terminally PQ IO)) schemas0 schemas1

301+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

302+ downMigrations = \case

303+ Done -> return ()

304+ step :>> steps -> downMigrations steps >> downMigration step

305+

306+ downMigration

307+ :: Migration (Terminally PQ IO) schemas0 schemas1

308+ -> PQ MigrationsSchemas MigrationsSchemas IO ()

309+ downMigration step = do

310+ executed <- queryExecuted step

311+ unless (executed == 0) $ do

312+ unsafePQ . runTerminally $ down step

313+ manipulateParams_ deleteMigration (Only (name step))

314+

315+ queryExecuted

316+ :: Migration (Terminally PQ IO) schemas0 schemas1

317+ -> PQ MigrationsSchemas MigrationsSchemas IO Row

318+ queryExecuted step = do

319+ result <- runQueryParams selectMigration (Only (name step))

320+ ntuples result

321+

322+unsafePQ :: (Functor m) => PQ db0 db1 m x -> PQ db0' db1' m x

323+unsafePQ (PQ pq) = PQ $ fmap (SOP.K . SOP.unK) . pq . SOP.K . SOP.unK

324+

325+-- | The `TableType` for a Squeal migration.

326+type MigrationsTable =

327+ '[ "migrations_unique_name" ::: 'Unique '["name"]] :=>

328+ '[ "name" ::: 'NoDef :=> 'NotNull 'PGtext

329+ , "executed_at" ::: 'Def :=> 'NotNull 'PGtimestamptz

330+ ]

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+

343+-- | Creates a `MigrationsTable` if it does not already exist.

344+createMigrations :: Definition MigrationsSchemas MigrationsSchemas

345+createMigrations =

346+ createTableIfNotExists #schema_migrations

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

348+ (timestampWithTimeZone & notNullable & default_ currentTimestamp)

349+ `as` #executed_at )

350+ ( unique #name `as` #migrations_unique_name )

351+

352+-- | Inserts a `Migration` into the `MigrationsTable`, returning

353+-- the time at which it was inserted.

354+insertMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

355+insertMigration = insertInto_ #schema_migrations

356+ (Values_ (Set (param @1) `as` #name :* Default `as` #executed_at))

357+

358+-- | Deletes a `Migration` from the `MigrationsTable`, returning

359+-- the time at which it was inserted.

360+deleteMigration :: Manipulation_ MigrationsSchemas (Only Text) ()

361+deleteMigration = deleteFrom_ #schema_migrations (#name .== param @1)

362+

363+-- | Selects a `Migration` from the `MigrationsTable`, returning

364+-- the time at which it was inserted.

365+selectMigration

366+ :: Query_ MigrationsSchemas (Only Text) (Only UTCTime)

367+selectMigration = select_ (#executed_at `as` #fromOnly)

368+ $ from (table (#schema_migrations))

369+ & where_ (#name .== param @1)

370+

371+selectMigrations :: Query_ MigrationsSchemas () MigrationRow

372+selectMigrations = select_

373+ (#name `as` #migrationName :* #executed_at `as` #migrationTime)

374+ (from (table #schema_migrations))

375+

376+data MigrateCommand

377+ = MigrateStatus

378+ | MigrateUp

379+ | MigrateDown deriving (GHC.Generic, Show)

380+

381+{- | `defaultMain` creates a simple executable

382+from a connection string and a list of `Migration`s. -}

383+defaultMain

384+ :: Migratory p

385+ => ByteString

386+ -- ^ connection string

387+ -> Path (Migration p) db0 db1

388+ -- ^ migrations

389+ -> IO ()

390+defaultMain connectTo migrations = do

391+ command <- readCommandFromArgs

392+ maybe (pure ()) performCommand command

393+

394+ where

395+

396+ performCommand :: MigrateCommand -> IO ()

397+ performCommand = \case

398+ MigrateStatus -> withConnection connectTo $

399+ suppressNotices >> migrateStatus

400+ MigrateUp -> withConnection connectTo $

401+ suppressNotices & pqThen (migrateUp migrations) & pqThen migrateStatus

402+ MigrateDown -> withConnection connectTo $

403+ suppressNotices & pqThen (migrateDown migrations) & pqThen migrateStatus

404+

405+ migrateStatus :: PQ schema schema IO ()

406+ migrateStatus = unsafePQ $ do

407+ runNames <- getRunMigrationNames

408+ let names = ctoList name migrations

409+ unrunNames = names \\ runNames

410+ liftIO $ displayRunned runNames >> displayUnrunned unrunNames

411+

412+ suppressNotices :: PQ schema schema IO ()

413+ suppressNotices = manipulate_ $

414+ UnsafeManipulation "SET client_min_messages TO WARNING;"

415+

416+ readCommandFromArgs :: IO (Maybe MigrateCommand)

417+ readCommandFromArgs = getArgs >>= \case

418+ ["migrate"] -> pure . Just $ MigrateUp

419+ ["rollback"] -> pure . Just $ MigrateDown

420+ ["status"] -> pure . Just $ MigrateStatus

421+ args -> displayUsage args >> pure Nothing

422+

423+ displayUsage :: [String] -> IO ()

424+ displayUsage args = do

425+ putStrLn $ "Invalid command: \"" <> unwords args <> "\". Use:"

426+ putStrLn "migrate to run all available migrations"

427+ putStrLn "rollback to rollback all available migrations"

428+ putStrLn "status to display migrations run and migrations left to run"

429+

430+ getRunMigrationNames :: (MonadIO m) => PQ db0 db0 m [Text]

431+ getRunMigrationNames =

432+ fmap migrationName <$> (unsafePQ (define createMigrations & pqThen (runQuery selectMigrations)) >>= getRows)

433+

434+ displayListOfNames :: [Text] -> IO ()

435+ displayListOfNames [] = Text.putStrLn " None"

436+ displayListOfNames xs =

437+ let singleName n = Text.putStrLn $ " - " <> n

438+ in traverse_ singleName xs

439+

440+ displayUnrunned :: [Text] -> IO ()

441+ displayUnrunned unrunned =

442+ Text.putStrLn "Migrations left to run:"

443+ >> displayListOfNames unrunned

444+

445+ displayRunned :: [Text] -> IO ()

446+ displayRunned runned =

447+ Text.putStrLn "Migrations already run:"

448+ >> displayListOfNames runned

squeal-postgresql/src/Squeal/PostgreSQL/PG.hsnew file+388

@@ -0,0 +1,388 @@

1+{-|

2+Module: Squeal.PostgreSQL.PG

3+Description: Embedding of Haskell types into Postgres's type system

4+Copyright: (c) Eitan Chatav, 2010

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+`Squeal.PostgreSQL.PG` provides type families for turning Haskell

9+`Type`s into corresponding Postgres types.

10+-}

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , DeriveAnyClass

14+ , DeriveFoldable

15+ , DeriveFunctor

16+ , DeriveGeneric

17+ , DeriveTraversable

18+ , DerivingStrategies

19+ , DefaultSignatures

20+ , FlexibleContexts

21+ , FlexibleInstances

22+ , FunctionalDependencies

23+ , GADTs

24+ , LambdaCase

25+ , MultiParamTypeClasses

26+ , OverloadedStrings

27+ , ScopedTypeVariables

28+ , TypeApplications

29+ , TypeFamilies

30+ , TypeInType

31+ , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

34+#-}

35+

36+module Squeal.PostgreSQL.PG

37+ ( -- * PG embeddings

38+ PG

39+ , NullPG

40+ , TuplePG

41+ , RowPG

42+ -- * Storage newtypes

43+ , Money (..)

44+ , Json (..)

45+ , Jsonb (..)

46+ , Composite (..)

47+ , Enumerated (..)

48+ , VarArray (..)

49+ , FixArray (..)

50+ , LibPQ.Oid (..)

51+ -- * Type families

52+ , LabelsPG

53+ , DimPG

54+ , FixPG

55+ , TupleOf

56+ , TupleCodeOf

57+ , RowOf

58+ , ConstructorsOf

59+ , ConstructorNameOf

60+ , ConstructorNamesOf

61+ ) where

62+

63+import Data.Aeson (Value)

64+import Data.Kind (Type)

65+import Data.Int (Int16, Int32, Int64)

66+import Data.Scientific (Scientific)

67+import Data.Time (Day, DiffTime, LocalTime, TimeOfDay, TimeZone, UTCTime)

68+import Data.Vector (Vector)

69+import Data.UUID.Types (UUID)

70+import GHC.TypeLits

71+import Network.IP.Addr (NetAddr, IP)

72+

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

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

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

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

77+import qualified Database.PostgreSQL.LibPQ as LibPQ

78+import qualified GHC.Generics as GHC

79+import qualified Generics.SOP as SOP

80+import qualified Generics.SOP.Record as SOP

81+import qualified Generics.SOP.Type.Metadata as Type

82+

83+import Squeal.PostgreSQL.Alias

84+import Squeal.PostgreSQL.Schema

85+

86+-- $setup

87+-- >>> import Squeal.PostgreSQL

88+-- >>> import Data.Text (Text)

89+

90+{- | The `PG` type family embeds a subset of Haskell types

91+as Postgres types. As an open type family, `PG` is extensible.

92+

93+>>> :kind! PG LocalTime

94+PG LocalTime :: PGType

95+= 'PGtimestamp

96+

97+>>> newtype MyDouble = My Double

98+>>> :set -XTypeFamilies

99+>>> type instance PG MyDouble = 'PGfloat8

100+-}

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

102+-- | `PGbool`

103+type instance PG Bool = 'PGbool

104+-- | `PGint2`

105+type instance PG Int16 = 'PGint2

106+-- | `PGint4`

107+type instance PG Int32 = 'PGint4

108+-- | `PGint8`

109+type instance PG Int64 = 'PGint8

110+-- | `PGint2`

111+type instance PG LibPQ.Oid = 'PGoid

112+-- | `PGnumeric`

113+type instance PG Scientific = 'PGnumeric

114+-- | `PGfloat4`

115+type instance PG Float = 'PGfloat4

116+-- | `PGfloat8`

117+type instance PG Double = 'PGfloat8

118+-- | `PGchar` @1@

119+type instance PG Char = 'PGchar 1

120+-- | `PGtext`

121+type instance PG Strict.Text = 'PGtext

122+-- | `PGtext`

123+type instance PG Lazy.Text = 'PGtext

124+-- | `PGtext`

125+type instance PG String = 'PGtext

126+-- | `PGbytea`

127+type instance PG Strict.ByteString = 'PGbytea

128+-- | `PGbytea`

129+type instance PG Lazy.ByteString = 'PGbytea

130+-- | `PGtimestamp`

131+type instance PG LocalTime = 'PGtimestamp

132+-- | `PGtimestamptz`

133+type instance PG UTCTime = 'PGtimestamptz

134+-- | `PGdate`

135+type instance PG Day = 'PGdate

136+-- | `PGtime`

137+type instance PG TimeOfDay = 'PGtime

138+-- | `PGtimetz`

139+type instance PG (TimeOfDay, TimeZone) = 'PGtimetz

140+-- | `PGinterval`

141+type instance PG DiffTime = 'PGinterval

142+-- | `PGuuid`

143+type instance PG UUID = 'PGuuid

144+-- | `PGinet`

145+type instance PG (NetAddr IP) = 'PGinet

146+-- | `PGjson`

147+type instance PG Value = 'PGjson

148+

149+{-| The `LabelsPG` type family calculates the constructors of a

150+Haskell enum type.

151+

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

153+>>> instance SOP.Generic Schwarma

154+>>> instance SOP.HasDatatypeInfo Schwarma

155+>>> :kind! LabelsPG Schwarma

156+LabelsPG Schwarma :: [Type.ConstructorName]

157+= '["Beef", "Lamb", "Chicken"]

158+-}

159+type family LabelsPG (hask :: Type) :: [Type.ConstructorName] where

160+ LabelsPG hask =

161+ ConstructorNamesOf (ConstructorsOf (SOP.DatatypeInfoOf hask))

162+

163+{- |

164+`RowPG` turns a Haskell `Type` into a `RowType`.

165+

166+`RowPG` may be applied to normal Haskell record types provided they

167+have `SOP.Generic` and `SOP.HasDatatypeInfo` instances;

168+

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

170+>>> instance SOP.Generic Person

171+>>> instance SOP.HasDatatypeInfo Person

172+>>> :kind! RowPG Person

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

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

175+-}

176+type family RowPG (hask :: Type) :: RowType where

177+ RowPG hask = RowOf (SOP.RecordCodeOf hask)

178+

179+-- | `RowOf` applies `NullPG` to the fields of a list.

180+type family RowOf (record :: [(Symbol, Type)]) :: RowType where

181+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': col4 ::: ty4 ': record) =

182+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': col4 ::: NullPG ty4 ': RowOf record

183+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': col3 ::: ty3 ': record) =

184+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': col3 ::: NullPG ty3 ': RowOf record

185+ RowOf (col ::: ty ': col1 ::: ty1 ': col2 ::: ty2 ': record) =

186+ col ::: NullPG ty ': col1 ::: NullPG ty1 ': col2 ::: NullPG ty2 ': RowOf record

187+ RowOf (col ::: ty ': col1 ::: ty1 ': record) =

188+ col ::: NullPG ty ': col1::: NullPG ty1 ': RowOf record

189+ RowOf (col ::: ty ': record) = col ::: NullPG ty ': RowOf record

190+ RowOf '[] = '[]

191+

192+{- | `NullPG` turns a Haskell type into a `NullityType`.

193+

194+>>> :kind! NullPG Double

195+NullPG Double :: NullityType

196+= 'NotNull 'PGfloat8

197+>>> :kind! NullPG (Maybe Double)

198+NullPG (Maybe Double) :: NullityType

199+= 'Null 'PGfloat8

200+-}

201+type family NullPG (hask :: Type) :: NullityType where

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

203+ NullPG hask = 'NotNull (PG hask)

204+

205+{- | `TuplePG` turns a Haskell tuple type (including record types) into

206+the corresponding list of `NullityType`s.

207+

208+>>> :kind! TuplePG (Double, Maybe Char)

209+TuplePG (Double, Maybe Char) :: [NullityType]

210+= '[ 'NotNull 'PGfloat8, 'Null ('PGchar 1)]

211+-}

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

213+ TuplePG hask = TupleOf (TupleCodeOf hask (SOP.Code hask))

214+

215+-- | `TupleOf` turns a list of Haskell `Type`s into a list of `NullityType`s.

216+type family TupleOf (tuple :: [Type]) :: [NullityType] where

217+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': hask5 ': tuple) =

218+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': NullPG hask5 ': TupleOf tuple

219+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': hask4 ': tuple) =

220+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': NullPG hask4 ': TupleOf tuple

221+ TupleOf (hask ': hask1 ': hask2 ': hask3 ': tuple) =

222+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': NullPG hask3 ': TupleOf tuple

223+ TupleOf (hask ': hask1 ': hask2 ': tuple) =

224+ NullPG hask ': NullPG hask1 ': NullPG hask2 ': TupleOf tuple

225+ TupleOf (hask ': hask1 ': tuple) = NullPG hask ': NullPG hask1 ': TupleOf tuple

226+ TupleOf (hask ': tuple) = NullPG hask ': TupleOf tuple

227+ TupleOf '[] = '[]

228+

229+-- | `TupleCodeOf` takes the `SOP.Code` of a haskell `Type`

230+-- and if it's a simple product returns it, otherwise giving a `TypeError`.

231+type family TupleCodeOf (hask :: Type) (code :: [[Type]]) :: [Type] where

232+ TupleCodeOf hask '[tuple] = tuple

233+ TupleCodeOf hask '[] =

234+ TypeError

235+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

236+ ':$$: 'Text "It is a void type with no constructors."

237+ )

238+ TupleCodeOf hask (_ ': _ ': _) =

239+ TypeError

240+ ( 'Text "The type `" ':<>: 'ShowType hask ':<>: 'Text "' is not a tuple type."

241+ ':$$: 'Text "It is a sum type with more than one constructor."

242+ )

243+

244+-- | Calculates constructors of a datatype.

245+type family ConstructorsOf (datatype :: Type.DatatypeInfo)

246+ :: [Type.ConstructorInfo] where

247+ ConstructorsOf ('Type.ADT _module _datatype constructors) =

248+ constructors

249+ ConstructorsOf ('Type.Newtype _module _datatype constructor) =

250+ '[constructor]

251+

252+-- | Calculates the name of a nullary constructor, otherwise

253+-- generates a type error.

254+type family ConstructorNameOf (constructor :: Type.ConstructorInfo)

255+ :: Type.ConstructorName where

256+ ConstructorNameOf ('Type.Constructor name) = name

257+ ConstructorNameOf ('Type.Infix name _assoc _fix) = TypeError

258+ ('Text "ConstructorNameOf error: non-nullary constructor "

259+ ':<>: 'Text name)

260+ ConstructorNameOf ('Type.Record name _fields) = TypeError

261+ ('Text "ConstructorNameOf error: non-nullary constructor "

262+ ':<>: 'Text name)

263+

264+-- | Calculate the names of nullary constructors.

265+type family ConstructorNamesOf (constructors :: [Type.ConstructorInfo])

266+ :: [Type.ConstructorName] where

267+ ConstructorNamesOf '[] = '[]

268+ ConstructorNamesOf (constructor ': constructors) =

269+ ConstructorNameOf constructor ': ConstructorNamesOf constructors

270+

271+-- | `DimPG` turns Haskell nested homogeneous tuples into a list of lengths.

272+type family DimPG (hask :: Type) :: [Nat] where

273+ DimPG (x,x) = 2 ': DimPG x

274+ DimPG (x,x,x) = 3 ': DimPG x

275+ DimPG (x,x,x,x) = 4 ': DimPG x

276+ DimPG (x,x,x,x,x) = 5 ': DimPG x

277+ DimPG (x,x,x,x,x,x) = 6 ': DimPG x

278+ DimPG (x,x,x,x,x,x,x) = 7 ': DimPG x

279+ DimPG (x,x,x,x,x,x,x,x) = 8 ': DimPG x

280+ DimPG (x,x,x,x,x,x,x,x,x) = 9 ': DimPG x

281+ DimPG (x,x,x,x,x,x,x,x,x,x) = 10 ': DimPG x

282+ DimPG x = '[]

283+

284+-- | `FixPG` extracts `NullPG` of the base type of nested homogeneous tuples.

285+type family FixPG (hask :: Type) :: NullityType where

286+ FixPG (x,x) = FixPG x

287+ FixPG (x,x,x) = FixPG x

288+ FixPG (x,x,x,x) = FixPG x

289+ FixPG (x,x,x,x,x) = FixPG x

290+ FixPG (x,x,x,x,x,x) = FixPG x

291+ FixPG (x,x,x,x,x,x,x) = FixPG x

292+ FixPG (x,x,x,x,x,x,x,x) = FixPG x

293+ FixPG (x,x,x,x,x,x,x,x,x) = FixPG x

294+ FixPG (x,x,x,x,x,x,x,x,x,x) = FixPG x

295+ FixPG (x,x,x,x,x,x,x,x,x,x,x) = FixPG x

296+ FixPG x = NullPG x

297+

298+{- | The `Money` newtype stores a monetary value in terms

299+of the number of cents, i.e. @$2,000.20@ would be expressed as

300+@Money { cents = 200020 }@.

301+

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

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

304+>>> import Squeal.PostgreSQL

305+>>> :{

306+let

307+ roundTrip :: Query_ (Public '[]) (Only Money) (Only Money)

308+ roundTrip = values_ $ parameter @1 money `as` #fromOnly

309+:}

310+

311+>>> let input = Only (Money 20020)

312+

313+>>> :{

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

315+ result <- runQueryParams roundTrip input

316+ Just output <- firstRow result

317+ liftIO . print $ input == output

318+:}

319+True

320+-}

321+newtype Money = Money { cents :: Int64 }

322+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

323+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

324+-- | `PGmoney`

325+type instance PG Money = 'PGmoney

326+

327+{- | The `Json` newtype is an indication that the Haskell

328+type it's applied to should be stored as a `PGjson`.

329+-}

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

331+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

332+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

333+-- | `PGjson`

334+type instance PG (Json hask) = 'PGjson

335+

336+{- | The `Jsonb` newtype is an indication that the Haskell

337+type it's applied to should be stored as a `PGjsonb`.

338+-}

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

340+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

341+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

342+-- | `PGjsonb`

343+type instance PG (Jsonb hask) = 'PGjsonb

344+

345+{- | The `Composite` newtype is an indication that the Haskell

346+type it's applied to should be stored as a `PGcomposite`.

347+-}

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

349+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

350+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

351+-- | `PGcomposite` @(@`RowPG` @hask)@

352+type instance PG (Composite hask) = 'PGcomposite (RowPG hask)

353+

354+{- | The `Enumerated` newtype is an indication that the Haskell

355+type it's applied to should be stored as a `PGenum`.

356+-}

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

358+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

359+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

360+-- | `PGenum` @(@`LabelsPG` @hask)@

361+type instance PG (Enumerated hask) = 'PGenum (LabelsPG hask)

362+

363+{- | The `VarArray` newtype is an indication that the Haskell

364+type it's applied to should be stored as a `PGvararray`.

365+

366+>>> :kind! PG (VarArray (Vector Double))

367+PG (VarArray (Vector Double)) :: PGType

368+= 'PGvararray ('NotNull 'PGfloat8)

369+-}

370+newtype VarArray arr = VarArray {getVarArray :: arr}

371+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

372+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

373+-- | `PGvararray` @(@`NullPG` @hask)@

374+type instance PG (VarArray (Vector hask)) = 'PGvararray (NullPG hask)

375+type instance PG (VarArray [hask]) = 'PGvararray (NullPG hask)

376+

377+{- | The `FixArray` newtype is an indication that the Haskell

378+type it's applied to should be stored as a `PGfixarray`.

379+

380+>>> :kind! PG (FixArray ((Double, Double), (Double, Double)))

381+PG (FixArray ((Double, Double), (Double, Double))) :: PGType

382+= 'PGfixarray '[2, 2] ('NotNull 'PGfloat8)

383+-}

384+newtype FixArray arr = FixArray {getFixArray :: arr}

385+ deriving stock (Eq, Ord, Show, Read, GHC.Generic)

386+ deriving anyclass (SOP.HasDatatypeInfo, SOP.Generic)

387+-- | `PGfixarray` @(@`DimPG` @hask) (@`FixPG` @hask)@

388+type instance PG (FixArray hask) = 'PGfixarray (DimPG hask) (FixPG hask)

squeal-postgresql/src/Squeal/PostgreSQL/PQ.hs+676−170

@@ -1,206 +1,712 @@

1+{-|

2+Module: Squeal.PostgreSQL.PQ

3+Description: PQ monad

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+This module is where Squeal commands actually get executed by

9+`Database.PostgreSQL.LibPQ`. It containts two typeclasses, `IndexedMonadTransPQ` for executing

10+a `Definition` and `MonadPQ` for executing a `Manipulation` or `Query`,

11+and a `PQ` type with instances for them.

12+

13+Using Squeal in your application will come down to defining

14+the @schemas@ of your database and including @PQ schemas schemas@ in your

15+application's monad transformer stack, giving it an instance of `MonadPQ`.

16+

17+This module also provides functions for retrieving rows from the `LibPQ.Result`

18+of executing Squeal commands.

19+-}

20+

1{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}

21{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}

2{-# LANGUAGE

22{-# LANGUAGE

3− DataKinds

4− , DefaultSignatures

23+ DefaultSignatures

5 , FunctionalDependencies

24 , FunctionalDependencies

6− , PolyKinds

7− , DeriveFunctor

8 , FlexibleContexts

25 , FlexibleContexts

9 , FlexibleInstances

26 , FlexibleInstances

10− , MagicHash

27+ , InstanceSigs

11− , MultiParamTypeClasses

28+ , OverloadedStrings

12 , RankNTypes

29 , RankNTypes

13 , ScopedTypeVariables

30 , ScopedTypeVariables

14 , TypeApplications

31 , TypeApplications

15 , TypeFamilies

32 , TypeFamilies

33+ , TypeInType

16 , TypeOperators

34 , TypeOperators

17 , UndecidableInstances

35 , UndecidableInstances

18#-}

36#-}

20−module Squeal.PostgreSQL.PQ where

38+module Squeal.PostgreSQL.PQ

21−

39+ ( -- * Connection

40+ LibPQ.Connection

41+ , connectdb

42+ , finish

43+ , withConnection

44+ , lowerConnection

45+ -- * PQ

46+ , PQ (PQ, unPQ)

47+ , runPQ

48+ , execPQ

49+ , evalPQ

50+ , IndexedMonadTransPQ (..)

51+ , MonadPQ (..)

52+ -- * Results

53+ , LibPQ.Result

54+ , LibPQ.Row

55+ , ntuples

56+ , getRow

57+ , getRows

58+ , nextRow

59+ , firstRow

60+ , liftResult

61+ , LibPQ.ExecStatus (..)

62+ , resultStatus

63+ , resultErrorMessage

64+ , resultErrorCode

65+ -- * Exceptions

66+ , SquealException (..)

67+ , PQState (..)

68+ , okResult

69+ , catchSqueal

70+ , handleSqueal

71+ , trySqueal

72+ ) where

73+

22−import Control.Exception.Lifted

74+import Control.Exception (Exception, throw)

23−import Control.Monad.Base

24import Control.Monad.Except

75import Control.Monad.Except

25−import Control.Monad.Trans.Control

76+import Control.Monad.Morph

77+import UnliftIO (MonadUnliftIO (..), bracket, catch, handle, try)

26import Data.ByteString (ByteString)

78import Data.ByteString (ByteString)

79+import Data.Foldable

27import Data.Function ((&))

80import Data.Function ((&))

81+import Data.Functor ((<&>))

82+import Data.Kind

83+import Data.Text (pack, Text)

84+import Data.Traversable

28import Generics.SOP

85import Generics.SOP

29−import GHC.Exts hiding (fromList)

86+import PostgreSQL.Binary.Encoding (encodingBytes)

30−import GHC.TypeLits

88+import qualified Control.Monad.Fail as Fail

32import qualified Database.PostgreSQL.LibPQ as LibPQ

89import qualified Database.PostgreSQL.LibPQ as LibPQ

90+import qualified PostgreSQL.Binary.Encoding as Encoding

34import Squeal.PostgreSQL.Binary

92import Squeal.PostgreSQL.Binary

35−import Squeal.PostgreSQL.Statement

93+import Squeal.PostgreSQL.Definition

94+import Squeal.PostgreSQL.Manipulation

95+import Squeal.PostgreSQL.Query

36import Squeal.PostgreSQL.Schema

96import Squeal.PostgreSQL.Schema

38−newtype Connection (schema :: [(Symbol,[(Symbol,ColumnType)])]) =

98+-- For `MonadPQ` transformer instances

39− Connection { unConnection :: LibPQ.Connection }

99+import Control.Monad.Trans.Identity

40−

100+import Control.Monad.Trans.Reader

101+import Control.Monad.Trans.Maybe

102+import Control.Monad.Trans.Cont

103+

104+import qualified Control.Monad.Trans.State.Lazy as Lazy

105+import qualified Control.Monad.Trans.State.Strict as Strict

106+import qualified Control.Monad.Trans.Writer.Lazy as Lazy

107+import qualified Control.Monad.Trans.Writer.Strict as Strict

108+import qualified Control.Monad.Trans.RWS.Lazy as Lazy

109+import qualified Control.Monad.Trans.RWS.Strict as Strict

110+

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

114+{- | Makes a new connection to the database server.

115+

116+This function opens a new database connection using the parameters taken

117+from the string conninfo.

118+

119+The passed string can be empty to use all default parameters, or it can

120+contain one or more parameter settings separated by whitespace.

121+Each parameter setting is in the form keyword = value. Spaces around the equal

122+sign are optional. To write an empty value or a value containing spaces,

123+surround it with single quotes, e.g., keyword = 'a value'. Single quotes and

124+backslashes within the value must be escaped with a backslash, i.e., ' and \.

125+

126+To specify the schema you wish to connect with, use type application.

127+

128+>>> :set -XDataKinds

129+>>> :set -XPolyKinds

130+>>> :set -XTypeOperators

131+>>> type Schema = '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint2]]

132+>>> :set -XTypeApplications

133+>>> :set -XOverloadedStrings

134+>>> conn <- connectdb @Schema "host=localhost port=5432 dbname=exampledb"

135+

136+Note that, for now, squeal doesn't offer any protection from connecting

137+with the wrong schema!

138+-}

139+connectdb

140+ :: forall schemas io

141+ . MonadIO io

142+ => ByteString -- ^ conninfo

143+ -> io (K LibPQ.Connection schemas)

144+connectdb = fmap K . liftIO . LibPQ.connectdb

145+

146+-- | Closes the connection to the server.

147+finish :: MonadIO io => K LibPQ.Connection schemas -> io ()

148+finish = liftIO . LibPQ.finish . unK

149+

150+-- | Do `connectdb` and `finish` before and after a computation.

151+withConnection

152+ :: forall schemas0 schemas1 io x

153+ . MonadUnliftIO io

154+ => ByteString

155+ -> PQ schemas0 schemas1 io x

156+ -> io x

157+withConnection connString action = do

158+ K x <- bracket (connectdb connString) finish (unPQ action)

159+ return x

160+

161+-- | Safely `lowerConnection` to a smaller schema.

162+lowerConnection

163+ :: K LibPQ.Connection (schema ': schemas)

164+ -> K LibPQ.Connection schemas

165+lowerConnection (K conn) = K conn

166+

167+-- | We keep track of the schema via an Atkey indexed state monad transformer,

168+-- `PQ`.

41newtype PQ

169newtype PQ

42− (schema0 :: [(Symbol,[(Symbol,ColumnType)])])

170+ (schemas0 :: SchemasType)

43− (schema1 :: [(Symbol,[(Symbol,ColumnType)])])

171+ (schemas1 :: SchemasType)

44− (m :: * -> *)

172+ (m :: Type -> Type)

45− (x :: *) =

173+ (x :: Type) =

46− PQ { unPQ :: Connection schema0 -> m (x, Connection schema1) }

174+ PQ { unPQ :: K LibPQ.Connection schemas0 -> m (K x schemas1) }

47− deriving Functor

175+

48−

176+instance Monad m => Functor (PQ schemas0 schemas1 m) where

49−evalPQ :: Functor m => Connection schema0 -> PQ schema0 schema1 m x -> m x

177+ fmap f (PQ pq) = PQ $ \ conn -> do

50−evalPQ conn (PQ pq) = fmap fst $ pq conn

178+ K x <- pq conn

51−

179+ return $ K (f x)

180+

181+-- | Run a `PQ` and keep the result and the `LibPQ.Connection`.

52runPQ

182runPQ

53 :: Functor m

183 :: Functor m

54− => Connection schema0

184+ => PQ schemas0 schemas1 m x

55− -> PQ schema0 schema1 m x

185+ -> K LibPQ.Connection schemas0

56− -> m (Connection schema1)

186+ -> m (x, K LibPQ.Connection schemas1)

57−runPQ conn (PQ pq) = fmap snd $ pq conn

187+runPQ (PQ pq) conn = (\ x -> (unK x, K (unK conn))) <$> pq conn

58−

188+ -- K x <- pq conn

59−pqAp

189+ -- return (x, K (unK conn))

60− :: Monad m

190+

61− => PQ schema0 schema1 m (x -> y)

191+-- | Execute a `PQ` and discard the result but keep the `LibPQ.Connection`.

62− -> PQ schema1 schema2 m x

192+execPQ

63− -> PQ schema0 schema2 m y

193+ :: Functor m

194+ => PQ schemas0 schemas1 m x

195+ -> K LibPQ.Connection schemas0

196+ -> m (K LibPQ.Connection schemas1)

197+execPQ (PQ pq) conn = mapKK (\ _ -> unK conn) <$> pq conn

198+

199+-- | Evaluate a `PQ` and discard the `LibPQ.Connection` but keep the result.

200+evalPQ

201+ :: Functor m

202+ => PQ schemas0 schemas1 m x

203+ -> K LibPQ.Connection schemas0

204+ -> m x

205+evalPQ (PQ pq) conn = unK <$> pq conn

206+

207+-- | An [Atkey indexed monad](https://bentnib.org/paramnotions-jfp.pdf) is a `Functor`

208+-- [enriched category](https://ncatlab.org/nlab/show/enriched+category).

209+-- An indexed monad transformer transforms a `Monad` into an indexed monad.

210+-- And, `IndexedMonadTransPQ` is a class for indexed monad transformers that

211+-- support running `Definition`s using `define`.

212+class IndexedMonadTransPQ pq where

213+

214+ -- | indexed analog of `<*>`

215+ pqAp

216+ :: Monad m

217+ => pq schemas0 schemas1 m (x -> y)

218+ -> pq schemas1 schemas2 m x

219+ -> pq schemas0 schemas2 m y

220+

221+ -- | indexed analog of `join`

222+ pqJoin

223+ :: Monad m

224+ => pq schemas0 schemas1 m (pq schemas1 schemas2 m y)

225+ -> pq schemas0 schemas2 m y

226+ pqJoin pq = pq & pqBind id

227+

228+ -- | indexed analog of `=<<`

229+ pqBind

230+ :: Monad m

231+ => (x -> pq schemas1 schemas2 m y)

232+ -> pq schemas0 schemas1 m x

233+ -> pq schemas0 schemas2 m y

234+

235+ -- | indexed analog of flipped `>>`

236+ pqThen

237+ :: Monad m

238+ => pq schemas1 schemas2 m y

239+ -> pq schemas0 schemas1 m x

240+ -> pq schemas0 schemas2 m y

241+ pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

242+

243+ -- | indexed analog of `<=<`

244+ pqAndThen

245+ :: Monad m

246+ => (y -> pq schemas1 schemas2 m z)

247+ -> (x -> pq schemas0 schemas1 m y)

248+ -> x -> pq schemas0 schemas2 m z

249+ pqAndThen g f x = pqBind g (f x)

250+

251+ -- | Run a `Definition` with `LibPQ.exec`.

252+ --

253+ -- It should be functorial in effect.

254+ --

255+ -- @define id = return ()@

256+ -- @define (statement1 >>> statement2) = define statement1 & pqThen (define statement2)@

257+ define

258+ :: MonadIO io

259+ => Definition schemas0 schemas1

260+ -> pq schemas0 schemas1 io ()

261+

262+instance IndexedMonadTransPQ PQ where

263+

64−pqAp (PQ f) (PQ x) = PQ $ \ conn -> do

264+ pqAp (PQ f) (PQ x) = PQ $ \ conn -> do

65− (f', conn') <- f conn

265+ K f' <- f conn

66− (x', conn'') <- x conn'

266+ K x' <- x (K (unK conn))

67− return (f' x', conn'')

267+ return $ K (f' x')

68−

268+

69−pqBind

70− :: Monad m

71− => (x -> PQ schema1 schema2 m y)

72− -> PQ schema0 schema1 m x

73− -> PQ schema0 schema2 m y

74−pqBind f (PQ x) = PQ $ \ conn -> do

269+ pqBind f (PQ x) = PQ $ \ conn -> do

75− (x', conn') <- x conn

270+ K x' <- x conn

76− unPQ (f x') conn'

271+ unPQ (f x') (K (unK conn))

77−

272+

78−pqThen

79− :: Monad m

80− => PQ schema1 schema2 m y

81− -> PQ schema0 schema1 m x

82− -> PQ schema0 schema2 m y

83−pqThen pq2 pq1 = pq1 & pqBind (\ _ -> pq2)

84−

85−pqExec

86− :: MonadBase IO io

87− => Definition schema0 schema1

88− -> PQ schema0 schema1 io (Maybe (Result '[]))

89−pqExec (UnsafeDefinition q) = PQ $ \ (Connection conn) -> do

273+ define (UnsafeDefinition q) = PQ $ \ (K conn) -> do

90− result <- liftBase $ LibPQ.exec conn q

274+ resultMaybe <- liftIO $ LibPQ.exec conn q

91− return (Result <$> result, Connection conn)

275+ case resultMaybe of

92−

276+ Nothing -> throw $ ResultException

93−pqThenExec

277+ "define: LibPQ.exec returned no results"

94− :: MonadBase IO io

278+ Just result -> K <$> okResult_ result

95− => Definition schema1 schema2

279+

96− -> PQ schema0 schema1 io x

280+{- | `MonadPQ` is an @mtl@ style constraint, similar to

97− -> PQ schema0 schema2 io (Maybe (Result '[]))

281+`Control.Monad.State.Class.MonadState`, for using `Database.PostgreSQL.LibPQ` to

98−pqThenExec = pqThen . pqExec

282+

99−

283+* `manipulateParams` runs a `Manipulation` with params from a type

100−class Monad m => MonadPQ schema m | m -> schema where

284+ with a `ToParams` constraint. It calls `LibPQ.execParams` and

101−

285+ doesn't afraid of anything.

102− pqExecParams

286+

103− :: ToParams x params

287+* `manipulateParams_` is like `manipulateParams` for a returning-free statement.

104− => Manipulation schema params ys -> x -> m (Maybe (Result ys))

288+

105− default pqExecParams

289+* `manipulate` is like `manipulateParams` for a parameter-free statement.

106− :: (MonadTrans t, MonadPQ schema m1, m ~ t m1)

290+

107− => ToParams x params

291+* `manipulate_` is like `manipulate` for a returning-free statement.

108− => Manipulation schema params ys -> x -> m (Maybe (Result ys))

292+

109− pqExecParams manipulation params = lift $ pqExecParams manipulation params

293+* `runQueryParams` is like `manipulateParams` for query statements.

110−

294+

111− pqExecNil :: Manipulation schema '[] ys -> m (Maybe (Result ys))

295+* `runQuery` is like `runQueryParams` for a parameter-free statement.

112− pqExecNil statement = pqExecParams statement ()

296+

113−

297+* `traversePrepared` has the same type signature as a composition of

114−instance MonadBase IO io => MonadPQ schema (PQ schema schema io) where

298+ `traverse` and `manipulateParams` but provides an optimization by

115−

299+ preparing the statement with `LibPQ.prepare` and then traversing a

116− pqExecParams (UnsafeManipulation q :: Manipulation schema ps ys) (params :: x) =

300+ `Traversable` container with `LibPQ.execPrepared`. The temporary prepared

117− PQ $ \ (Connection conn) -> do

301+ statement is then deallocated.

118− let

302+

119− toParam' bytes = (LibPQ.invalidOid,bytes,LibPQ.Binary)

303+* `forPrepared` is a flipped `traversePrepared`

120− params' = fmap (fmap toParam') (hcollapse (toParams @x @ps params))

304+

121− result <- liftBase $ LibPQ.execParams conn q params' LibPQ.Binary

305+* `traversePrepared_` is like `traversePrepared` but works on `Foldable`

122− return (Result <$> result, Connection conn)

306+ containers for a returning-free statement.

123−

307+

308+* `forPrepared_` is a flipped `traversePrepared_`.

309+

310+* `liftPQ` lets you lift actions from `Database.PostgreSQL.LibPQ` that require a connection

311+ into your monad.

312+

313+To define an instance, you can minimally define only `manipulateParams`,

314+`traversePrepared`, `traversePrepared_` and `liftPQ`. Monad transformers get

315+a default instance.

316+

317+-}

318+class Monad pq => MonadPQ schemas pq | pq -> schemas where

319+ manipulateParams

320+ :: (ToParams x params, All OidOfParam params)

321+ => Manipulation '[] schemas params ys

322+ -- ^ `insertInto`, `update` or `deleteFrom`

323+ -> x -> pq (K LibPQ.Result ys)

324+ default manipulateParams

325+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

326+ => (ToParams x params, All OidOfParam params)

327+ => Manipulation '[] schemas params ys

328+ -- ^ `insertInto`, `update` or `deleteFrom`

329+ -> x -> pq (K LibPQ.Result ys)

330+ manipulateParams manipulation params = lift $

331+ manipulateParams manipulation params

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+

340+ manipulate :: Manipulation '[] schemas '[] ys -> pq (K LibPQ.Result ys)

341+ manipulate statement = manipulateParams statement ()

342+

343+ manipulate_ :: Manipulation '[] schemas '[] '[] -> pq ()

344+ manipulate_ = void . manipulate

345+

346+ runQueryParams

347+ :: (ToParams x params, All OidOfParam params)

348+ => Query '[] '[] schemas params ys

349+ -- ^ `select` and friends

350+ -> x -> pq (K LibPQ.Result ys)

351+ runQueryParams = manipulateParams . queryStatement

352+

353+ runQuery

354+ :: Query '[] '[] schemas '[] ys

355+ -- ^ `select` and friends

356+ -> pq (K LibPQ.Result ys)

357+ runQuery q = runQueryParams q ()

358+

359+ traversePrepared

360+ :: (ToParams x params, Traversable list, All OidOfParam params)

361+ => Manipulation '[] schemas params ys

362+ -- ^ `insertInto`, `update`, or `deleteFrom`, and friends

363+ -> list x -> pq (list (K LibPQ.Result ys))

364+ default traversePrepared

365+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

366+ => (ToParams x params, Traversable list, All OidOfParam params)

367+ => Manipulation '[] schemas params ys -> list x -> pq (list (K LibPQ.Result ys))

368+ traversePrepared manipulation params = lift $

369+ traversePrepared manipulation params

370+

371+ forPrepared

372+ :: (ToParams x params, Traversable list, All OidOfParam params)

373+ => list x

374+ -> Manipulation '[] schemas params ys

375+ -- ^ `insertInto`, `update` or `deleteFrom`

376+ -> pq (list (K LibPQ.Result ys))

377+ forPrepared = flip traversePrepared

378+

379+ traversePrepared_

380+ :: (ToParams x params, Foldable list, All OidOfParam params)

381+ => Manipulation '[] schemas params '[]

382+ -- ^ `insertInto`, `update` or `deleteFrom`

383+ -> list x -> pq ()

384+ default traversePrepared_

385+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

386+ => (ToParams x params, Foldable list, All OidOfParam params)

387+ => Manipulation '[] schemas params '[]

388+ -- ^ `insertInto`, `update` or `deleteFrom`

389+ -> list x -> pq ()

390+ traversePrepared_ manipulation params = lift $

391+ traversePrepared_ manipulation params

392+

393+ forPrepared_

394+ :: (ToParams x params, Foldable list, All OidOfParam params)

395+ => list x

396+ -> Manipulation '[] schemas params '[]

397+ -- ^ `insertInto`, `update` or `deleteFrom`

398+ -> pq ()

399+ forPrepared_ = flip traversePrepared_

400+

401+ liftPQ :: (LibPQ.Connection -> IO a) -> pq a

402+ default liftPQ

403+ :: (MonadTrans t, MonadPQ schemas pq1, pq ~ t pq1)

404+ => (LibPQ.Connection -> IO a) -> pq a

405+ liftPQ = lift . liftPQ

406+

407+instance (MonadIO io, schemas0 ~ schemas, schemas1 ~ schemas)

408+ => MonadPQ schemas (PQ schemas0 schemas1 io) where

409+

410+ manipulateParams

411+ (UnsafeManipulation q :: Manipulation '[] schemas ps ys) (params :: x) =

412+ PQ $ \ (K conn) -> do

413+ let

414+ paramSet

415+ :: forall param. OidOfParam param

416+ => K (Maybe Encoding.Encoding) param

417+ -> K (Maybe (LibPQ.Oid, ByteString, LibPQ.Format)) param

418+ paramSet (K maybeEncoding) = K $

419+ maybeEncoding <&> \encoding ->

420+ (oidOfParam @param, encodingBytes encoding, LibPQ.Binary)

421+ params'

422+ = hcollapse

423+ . hcmap (Proxy @OidOfParam) paramSet

424+ $ toParams @x @ps params

425+ q' = q <> ";"

426+ resultMaybe <- liftIO $ LibPQ.execParams conn q' params' LibPQ.Binary

427+ case resultMaybe of

428+ Nothing -> throw $ ResultException

429+ "manipulateParams: LibPQ.execParams returned no results"

430+ Just result -> do

431+ okResult_ result

432+ return $ K (K result)

433+

434+ traversePrepared

435+ (UnsafeManipulation q :: Manipulation '[] schemas xs ys) (list :: list x) =

436+ PQ $ \ (K conn) -> liftIO $ do

437+ let

438+ temp = "temporary_statement"

439+ paramOid :: forall p. OidOfParam p => K LibPQ.Oid p

440+ paramOid = K (oidOfParam @p)

441+ paramOids :: NP (K LibPQ.Oid) xs

442+ paramOids = hcpure (Proxy @OidOfParam) paramOid

443+ paramOids' :: [LibPQ.Oid]

444+ paramOids' = hcollapse paramOids

445+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

446+ case prepResultMaybe of

447+ Nothing -> throw $ ResultException

448+ "traversePrepared: LibPQ.prepare returned no results"

449+ Just prepResult -> okResult_ prepResult

450+ results <- for list $ \ params -> do

451+ let

452+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

453+ params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

454+ resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

455+ case resultMaybe of

456+ Nothing -> throw $ ResultException

457+ "traversePrepared: LibPQ.execParams returned no results"

458+ Just result -> do

459+ okResult_ result

460+ return $ K result

461+ deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

462+ case deallocResultMaybe of

463+ Nothing -> throw $ ResultException

464+ "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

465+ Just deallocResult -> okResult_ deallocResult

466+ return (K results)

467+

468+ traversePrepared_

469+ (UnsafeManipulation q :: Manipulation '[] schemas xs '[]) (list :: list x) =

470+ PQ $ \ (K conn) -> liftIO $ do

471+ let

472+ temp = "temporary_statement"

473+ paramOid :: forall p. OidOfParam p => K LibPQ.Oid p

474+ paramOid = K (oidOfParam @p)

475+ paramOids :: NP (K LibPQ.Oid) xs

476+ paramOids = hcpure (Proxy @OidOfParam) paramOid

477+ paramOids' :: [LibPQ.Oid]

478+ paramOids' = hcollapse paramOids

479+ prepResultMaybe <- LibPQ.prepare conn temp q (Just paramOids')

480+ case prepResultMaybe of

481+ Nothing -> throw $ ResultException

482+ "traversePrepared_: LibPQ.prepare returned no results"

483+ Just prepResult -> okResult_ prepResult

484+ for_ list $ \ params -> do

485+ let

486+ toParam' encoding = (encodingBytes encoding, LibPQ.Binary)

487+ params' = fmap (fmap toParam') (hcollapse (toParams @x @xs params))

488+ resultMaybe <- LibPQ.execPrepared conn temp params' LibPQ.Binary

489+ case resultMaybe of

490+ Nothing -> throw $ ResultException

491+ "traversePrepared_: LibPQ.execParams returned no results"

492+ Just result -> okResult_ result

493+ deallocResultMaybe <- LibPQ.exec conn ("DEALLOCATE " <> temp <> ";")

494+ case deallocResultMaybe of

495+ Nothing -> throw $ ResultException

496+ "traversePrepared: LibPQ.exec DEALLOCATE returned no results"

497+ Just deallocResult -> okResult_ deallocResult

498+ return (K ())

499+

500+ liftPQ pq = PQ $ \ (K conn) -> do

501+ y <- liftIO $ pq conn

502+ return (K y)

503+

504+instance MonadPQ schemas m => MonadPQ schemas (IdentityT m)

505+instance MonadPQ schemas m => MonadPQ schemas (ReaderT r m)

506+instance MonadPQ schemas m => MonadPQ schemas (Strict.StateT s m)

507+instance MonadPQ schemas m => MonadPQ schemas (Lazy.StateT s m)

508+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.WriterT w m)

509+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.WriterT w m)

510+instance MonadPQ schemas m => MonadPQ schemas (MaybeT m)

511+instance MonadPQ schemas m => MonadPQ schemas (ExceptT e m)

512+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Strict.RWST r w s m)

513+instance (Monoid w, MonadPQ schemas m) => MonadPQ schemas (Lazy.RWST r w s m)

514+instance MonadPQ schemas m => MonadPQ schemas (ContT r m)

515+

516+instance (Monad m, schemas0 ~ schemas1)

124−instance Monad m => Applicative (PQ schema schema m) where

517+ => Applicative (PQ schemas0 schemas1 m) where

125− pure x = PQ $ \ conn -> pure (x, conn)

518+ pure x = PQ $ \ _conn -> pure (K x)

126 (<*>) = pqAp

519 (<*>) = pqAp

127

520

128−instance Monad m => Monad (PQ schema schema m) where

521+instance (Monad m, schemas0 ~ schemas1)

522+ => Monad (PQ schemas0 schemas1 m) where

129 return = pure

523 return = pure

130 (>>=) = flip pqBind

524 (>>=) = flip pqBind

131

525

132−instance MonadTrans (PQ schema schema) where

526+instance (Monad m, schemas0 ~ schemas1)

133− lift m = PQ $ \ conn -> do

527+ => Fail.MonadFail (PQ schemas0 schemas1 m) where

134− x <- m

528+ fail = Fail.fail

135− return (x, conn)

136−

137−instance MonadBase b m => MonadBase b (PQ schema schema m) where

138− liftBase = lift . liftBase

139

529

140−type PQRun schema =

530+instance schemas0 ~ schemas1 => MFunctor (PQ schemas0 schemas1) where

141− forall m x. Monad m => PQ schema schema m x -> m (x, Connection schema)

531+ hoist f (PQ pq) = PQ (f . pq)

142−

143−pqliftWith :: Functor m => (PQRun schema -> m a) -> PQ schema schema m a

144−pqliftWith f = PQ $ \ conn ->

145− fmap (\ x -> (x, conn)) (f $ \ pq -> unPQ pq conn)

146−

147−instance MonadBaseControl b m => MonadBaseControl b (PQ schema schema m) where

148− type StM (PQ schema schema m) x = StM m (x, Connection schema)

149− liftBaseWith f =

150− pqliftWith $ \ run -> liftBaseWith $ \ runInBase -> f $ runInBase . run

151− restoreM = PQ . const . restoreM

152−

153−connectdb :: MonadBase IO io => ByteString -> io (Connection schema)

154−connectdb = fmap Connection . liftBase . LibPQ.connectdb

155−

156−finish :: MonadBase IO io => Connection schema -> io ()

157−finish = liftBase . LibPQ.finish . unConnection

158−

159−withConnection

160− :: MonadBaseControl IO io

161− => ByteString

162− -> (Connection schema -> io x)

163− -> io x

164−withConnection connString action =

165− bracket (connectdb connString) finish action

166−

167−newtype Result (xs :: [(Symbol,ColumnType)])

168− = Result { unResult :: LibPQ.Result }

169−

170−newtype RowNumber = RowNumber { unRowNumber :: LibPQ.Row }

171−

172−newtype ColumnNumber n cs c =

173− UnsafeColumnNumber { getColumnNumber :: LibPQ.Column }

174−

175−class KnownNat n => HasColumnNumber n columns column

176− | n columns -> column where

177− columnNumber :: ColumnNumber n columns column

178− columnNumber =

179− UnsafeColumnNumber . fromIntegral $ natVal' (proxy# :: Proxy# n)

180−instance {-# OVERLAPPING #-} HasColumnNumber 0 (column1:columns) column1

181−instance {-# OVERLAPPABLE #-}

182− (KnownNat n, HasColumnNumber (n-1) columns column)

183− => HasColumnNumber n (column' : columns) column

184−

185−getValue

186− :: (FromColumnValue colty y, MonadBase IO io)

187− => RowNumber

188− -> ColumnNumber n columns colty

189− -> Result columns

190− -> io y

191−getValue

192− (RowNumber r)

193− (UnsafeColumnNumber c :: ColumnNumber n columns colty)

194− (Result result)

195− = fromColumnValue @colty . K <$>

196− liftBase (LibPQ.getvalue result r c)

197

532

533+instance schemas0 ~ schemas1 => MonadTrans (PQ schemas0 schemas1) where

534+ lift m = PQ $ \ _conn -> do

535+ x <- m

536+ return (K x)

537+

538+instance schemas0 ~ schemas1 => MMonad (PQ schemas0 schemas1) where

539+ embed f (PQ pq) = PQ $ \ conn -> do

540+ evalPQ (f (pq conn)) conn

541+

542+instance (MonadIO m, schema0 ~ schema1)

543+ => MonadIO (PQ schema0 schema1 m) where

544+ liftIO = lift . liftIO

545+

546+instance (MonadUnliftIO m, schemas0 ~ schemas1)

547+ => MonadUnliftIO (PQ schemas0 schemas1 m) where

548+ withRunInIO

549+ :: ((forall a . PQ schemas0 schema1 m a -> IO a) -> IO b)

550+ -> PQ schemas0 schema1 m b

551+ withRunInIO inner = PQ $ \conn ->

552+ withRunInIO $ \(run :: (forall x . m x -> IO x)) ->

553+ K <$> inner (\pq -> run $ unK <$> unPQ pq conn)

554+

555+-- | Get a row corresponding to a given row number from a `LibPQ.Result`,

556+-- throwing an exception if the row number is out of bounds.

198getRow

557getRow

199− :: (FromRow columns y, MonadBase IO io)

558+ :: (FromRow columns y, MonadIO io)

559+ => LibPQ.Row

560+ -- ^ row number

200− => RowNumber -> Result columns -> io y

561+ -> K LibPQ.Result columns

562+ -- ^ result

563+ -> io y

201−getRow (RowNumber r) (Result result :: Result columns) = do

564+getRow r (K result :: K LibPQ.Result columns) = liftIO $ do

565+ numRows <- LibPQ.ntuples result

566+ when (numRows < r) $ throw $ ResultException $

567+ "getRow: expected at least " <> pack (show r) <> "rows but only saw "

568+ <> pack (show numRows)

202 let len = fromIntegral (lengthSList (Proxy @columns))

569 let len = fromIntegral (lengthSList (Proxy @columns))

203− row' <- traverse (liftBase . LibPQ.getvalue result r) [0 .. len - 1]

570+ row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

204 case fromList row' of

571 case fromList row' of

205− Nothing -> error "getRow: found unexpected length"

572+ Nothing -> throw $ ResultException "getRow: found unexpected length"

573+ Just row -> case fromRow @columns row of

574+ Left parseError -> throw $ ParseException $ "getRow: " <> parseError

575+ Right y -> return y

576+

577+-- | Intended to be used for unfolding in streaming libraries, `nextRow`

578+-- takes a total number of rows (which can be found with `ntuples`)

579+-- and a `LibPQ.Result` and given a row number if it's too large returns `Nothing`,

580+-- otherwise returning the row along with the next row number.

581+nextRow

582+ :: (FromRow columns y, MonadIO io)

583+ => LibPQ.Row -- ^ total number of rows

584+ -> K LibPQ.Result columns -- ^ result

585+ -> LibPQ.Row -- ^ row number

586+ -> io (Maybe (LibPQ.Row,y))

587+nextRow total (K result :: K LibPQ.Result columns) r

588+ = liftIO $ if r >= total then return Nothing else do

589+ let len = fromIntegral (lengthSList (Proxy @columns))

590+ row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

591+ case fromList row' of

592+ Nothing -> throw $ ResultException "nextRow: found unexpected length"

206− Just row -> return $ fromRow @columns row

593+ Just row -> case fromRow @columns row of

594+ Left parseError -> throw $ ParseException $ "nextRow: " <> parseError

595+ Right y -> return $ Just (r+1, y)

596+

597+-- | Get all rows from a `LibPQ.Result`.

598+getRows

599+ :: (FromRow columns y, MonadIO io)

600+ => K LibPQ.Result columns -- ^ result

601+ -> io [y]

602+getRows (K result :: K LibPQ.Result columns) = liftIO $ do

603+ let len = fromIntegral (lengthSList (Proxy @columns))

604+ numRows <- LibPQ.ntuples result

605+ for [0 .. numRows - 1] $ \ r -> do

606+ row' <- traverse (LibPQ.getvalue result r) [0 .. len - 1]

607+ case fromList row' of

608+ Nothing -> throw $ ResultException "getRows: found unexpected length"

609+ Just row -> case fromRow @columns row of

610+ Left parseError -> throw $ ParseException $ "getRows: " <> parseError

611+ Right y -> return y

612+

613+-- | Get the first row if possible from a `LibPQ.Result`.

614+firstRow

615+ :: (FromRow columns y, MonadIO io)

616+ => K LibPQ.Result columns -- ^ result

617+ -> io (Maybe y)

618+firstRow (K result :: K LibPQ.Result columns) = liftIO $ do

619+ numRows <- LibPQ.ntuples result

620+ if numRows <= 0 then return Nothing else do

621+ let len = fromIntegral (lengthSList (Proxy @columns))

622+ row' <- traverse (LibPQ.getvalue result 0) [0 .. len - 1]

623+ case fromList row' of

624+ Nothing -> throw $ ResultException "firstRow: found unexpected length"

625+ Just row -> case fromRow @columns row of

626+ Left parseError -> throw $ ParseException $ "firstRow: " <> parseError

627+ Right y -> return $ Just y

628+

629+-- | Lifts actions on results from @LibPQ@.

630+liftResult

631+ :: MonadIO io

632+ => (LibPQ.Result -> IO x)

633+ -> K LibPQ.Result results -> io x

634+liftResult f (K result) = liftIO $ f result

635+

636+-- | Returns the number of rows (tuples) in the query result.

637+ntuples :: MonadIO io => K LibPQ.Result columns -> io LibPQ.Row

638+ntuples = liftResult LibPQ.ntuples

639+

640+-- | Returns the result status of the command.

641+resultStatus :: MonadIO io => K LibPQ.Result results -> io LibPQ.ExecStatus

642+resultStatus = liftResult LibPQ.resultStatus

643+

644+-- | Returns the error message most recently generated by an operation

645+-- on the connection.

646+resultErrorMessage

647+ :: MonadIO io => K LibPQ.Result results -> io (Maybe ByteString)

648+resultErrorMessage = 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.hsnew file+122

@@ -0,0 +1,122 @@

1+{-|

2+Module: Squeal.PostgreSQL.Pool

3+Description: Connection pools

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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

31+-}

32+

33+{-# LANGUAGE

34+ DeriveFunctor

35+ , FlexibleContexts

36+ , FlexibleInstances

37+ , InstanceSigs

38+ , MultiParamTypeClasses

39+ , RankNTypes

40+ , ScopedTypeVariables

41+ , TypeFamilies

42+ , TypeInType

43+ , UndecidableInstances

44+#-}

45+

46+module Squeal.PostgreSQL.Pool

47+ ( -- * Pools

48+ Pool

49+ , createConnectionPool

50+ , usingConnectionPool

51+ , destroyConnectionPool

52+ ) where

53+

54+import Data.ByteString

55+import Data.Time

56+import Generics.SOP (K(..), unK)

57+import UnliftIO (MonadUnliftIO (..))

58+import UnliftIO.Pool (Pool, createPool, destroyAllResources, withResource)

59+

60+import Squeal.PostgreSQL.PQ

61+

62+-- | Create a striped pool of connections.

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.

64+createConnectionPool

65+ :: MonadUnliftIO io

66+ => ByteString

67+ -- ^ The passed string can be empty to use all default parameters, or it can

68+ -- contain one or more parameter settings separated by whitespace.

69+ -- Each parameter setting is in the form keyword = value. Spaces around the equal

70+ -- sign are optional. To write an empty value or a value containing spaces,

71+ -- surround it with single quotes, e.g., keyword = 'a value'. Single quotes and

72+ -- backslashes within the value must be escaped with a backslash, i.e., ' and \.

73+ -> Int

74+ -- ^ The number of stripes (distinct sub-pools) to maintain. The smallest acceptable value is 1.

75+ -> NominalDiffTime

76+ -- ^ Amount of time for which an unused connection is kept open. The smallest acceptable value is 0.5 seconds.

77+ -- The elapsed time before destroying a connection may be a little longer than requested, as the reaper thread wakes at 1-second intervals.

78+ -> Int

79+ -- ^ Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

80+ -- Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

81+ -> io (Pool (K Connection schemas))

82+createConnectionPool conninfo stripes idle maxResrc =

83+ createPool (connectdb conninfo) finish stripes idle maxResrc

84+

85+{-|

86+Temporarily take a connection from a `Pool`, perform an action with it,

87+and return it to the pool afterwards.

88+

89+If the pool has an idle connection available, it is used immediately.

90+Otherwise, if the maximum number of connections has not yet been reached,

91+a new connection is created and used.

92+If the maximum number of connections has been reached, this function blocks

93+until a connection becomes available.

94+-}

95+usingConnectionPool

96+ :: MonadUnliftIO io

97+ => Pool (K Connection schemas) -- ^ pool

98+ -> PQ schemas schemas io x -- ^ session

99+ -> io x

100+usingConnectionPool pool (PQ session) = unK <$> withResource pool session

101+

102+{- |

103+Destroy all connections in all stripes in the pool.

104+Note that this will ignore any exceptions in the destroy function.

105+

106+This function is useful when you detect that all connections

107+in the pool are broken. For example after a database has been

108+restarted all connections opened before the restart will be broken.

109+In that case it's better to close those connections so that

110+`usingConnectionPool` won't take a broken connection from the pool

111+but will open a new connection instead.

112+

113+Another use-case for this function is that when you know you are done

114+with the pool you can destroy all idle connections immediately

115+instead of waiting on the garbage collector to destroy them,

116+thus freeing up those connections sooner.

117+-}

118+destroyConnectionPool

119+ :: MonadUnliftIO io

120+ => Pool (K Connection schemas) -- ^ pool

121+ -> io ()

122+destroyConnectionPool = destroyAllResources

squeal-postgresql/src/Squeal/PostgreSQL/Query.hsnew file+1098

@@ -0,0 +1,1098 @@

1+{-|

2+Module: Squeal.PostgreSQL.Query

3+Description: Squeal queries

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Squeal queries.

9+-}

10+

11+{-# LANGUAGE

12+ ConstraintKinds

13+ , DeriveGeneric

14+ , FlexibleContexts

15+ , FlexibleInstances

16+ , GADTs

17+ , GeneralizedNewtypeDeriving

18+ , LambdaCase

19+ , MultiParamTypeClasses

20+ , OverloadedLabels

21+ , OverloadedStrings

22+ , QuantifiedConstraints

23+ , ScopedTypeVariables

24+ , StandaloneDeriving

25+ , TypeApplications

26+ , TypeFamilies

27+ , TypeInType

28+ , TypeOperators

29+ , RankNTypes

30+ , UndecidableInstances

31+ #-}

32+

33+module Squeal.PostgreSQL.Query

34+ ( -- * Queries

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

49+ , union

50+ , unionAll

51+ , intersect

52+ , intersectAll

53+ , except

54+ , exceptAll

55+ -- ** With

56+ , With (..)

57+ , CommonTableExpression (..)

58+ , withRecursive

59+ -- * Table Expressions

60+ , TableExpression (..)

61+ , from

62+ , where_

63+ , groupBy

64+ , having

65+ , limit

66+ , offset

67+ -- * From Clauses

68+ , FromClause (..)

69+ , table

70+ , subquery

71+ , view

72+ , common

73+ , crossJoin

74+ , innerJoin

75+ , leftOuterJoin

76+ , rightOuterJoin

77+ , fullOuterJoin

78+ -- * Grouping

79+ , By (..)

80+ , GroupByClause (..)

81+ , HavingClause (..)

82+ ) where

83+

84+import Control.DeepSeq

85+import Data.ByteString (ByteString)

86+import Data.Kind (Type)

87+import Data.String

88+import Data.Word

89+import Generics.SOP hiding (from)

90+import GHC.TypeLits

91+

92+import qualified GHC.Generics as GHC

93+

94+import Squeal.PostgreSQL.Alias

95+import 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

101+import Squeal.PostgreSQL.Render

102+import Squeal.PostgreSQL.Schema

103+

104+-- $setup

105+-- >>> import Squeal.PostgreSQL

106+-- >>> import Data.Int (Int32, Int64)

107+-- >>> import Data.Monoid (Sum (..))

108+-- >>> import Data.Text (Text)

109+-- >>> import qualified Generics.SOP as SOP

110+

111+{- |

112+The process of retrieving or the command to retrieve data from

113+a database is called a `Query`.

114+

115+The general `Query` type is parameterized by

116+

117+* @outer :: FromType@ - outer scope for a correlated subquery,

118+* @commons :: FromType@ - scope for all `common` table expressions,

119+* @schemas :: SchemasType@ - scope for all `table`s and `view`s,

120+* @params :: [NullityType]@ - scope for all `Squeal.Expression.Parameter.parameter`s,

121+* @row :: RowType@ - return type of the `Query`.

122+-}

123+newtype Query

124+ (outer :: FromType)

125+ (commons :: FromType)

126+ (schemas :: SchemasType)

127+ (params :: [NullityType])

128+ (row :: RowType)

129+ = UnsafeQuery { renderQuery :: ByteString }

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

131+instance RenderSQL (Query outer commons schemas params row) where renderSQL = renderQuery

132+

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+

156+simple query:

157+

158+>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]

159+>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]

160+>>> :{

161+let

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

163+ query = select Star (from (table #tab))

164+in printSQL query

165+:}

166+SELECT * FROM "tab" AS "tab"

167+

168+restricted query:

169+

170+>>> :{

171+let

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

173+ query =

174+ select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)

175+ ( from (table #tab)

176+ & where_ (#col1 .> #col2)

177+ & where_ (#col2 .> 0) )

178+in printSQL query

179+:}

180+SELECT ("col1" + "col2") AS "col1", "col1" AS "col2" FROM "tab" AS "tab" WHERE (("col1" > "col2") AND ("col2" > 0))

181+

182+subquery:

183+

184+>>> :{

185+let

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

187+ query = select Star (from (subquery (select Star (from (table #tab)) `as` #sub)))

188+in printSQL query

189+:}

190+SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"

191+

192+limits and offsets:

193+

194+>>> :{

195+let

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

197+ query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)

198+in printSQL query

199+:}

200+SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4

201+

202+parameterized query:

203+

204+>>> :{

205+let

206+ query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)

207+ query = select Star (from (table #tab) & where_ (#col1 .> param @1))

208+in printSQL query

209+:}

210+SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))

211+

212+aggregation query:

213+

214+>>> :{

215+let

216+ query :: Query_ (Public Schema) () (Row Int64 Int32)

217+ query =

218+ select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)

219+ ( from (table (#tab `as` #table1))

220+ & groupBy #col1

221+ & having (sum_ (Distinct #col2) .> 1) )

222+in printSQL query

223+:}

224+SELECT COALESCE(sum(ALL "col2"), 0) AS "col1", "col1" AS "col2" FROM "tab" AS "table1" GROUP BY "col1" HAVING (sum(DISTINCT "col2") > 1)

225+

226+sorted query:

227+

228+>>> :{

229+let

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

231+ query = select Star (from (table #tab) & orderBy [#col1 & Asc])

232+in printSQL query

233+:}

234+SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC

235+

236+joins:

237+

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+

273+>>> :{

274+let

275+ query :: Query_ (Public OrdersSchema) () Order

276+ query = select_

277+ ( #o ! #price `as` #price :*

278+ #c ! #name `as` #customerName :*

279+ #s ! #name `as` #shipperName )

280+ ( from (table (#orders `as` #o)

281+ & innerJoin (table (#customers `as` #c))

282+ (#o ! #customer_id .== #c ! #id)

283+ & innerJoin (table (#shippers `as` #s))

284+ (#o ! #shipper_id .== #s ! #id)) )

285+in printSQL query

286+:}

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")

288+

289+self-join:

290+

291+>>> :{

292+let

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

294+ query = select

295+ (#t1 & DotStar)

296+ (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))

297+in printSQL query

298+:}

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")

312+

313+set operations:

314+

315+>>> :{

316+let

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

318+ query = select Star (from (table #tab)) `unionAll` select Star (from (table #tab))

319+in printSQL query

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)

353+ query =

354+ select (#col1 `as` #fromOnly) (from (table (#tab `as` #t1))

355+ & where_ (exists (

356+ select Star (from (table (#tab `as` #t2))

357+ & where_ (#t2 ! #col2 .== #t1 ! #col1)))))

358+in printSQL query

359+:}

360+SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))

361+

362+-}

363+type family Query_

364+ (schemas :: SchemasType)

365+ (parameters :: Type)

366+ (row :: Type) where

367+ Query_ schemas params row =

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

369+

370+-- | The results of two queries can be combined using the set operation

371+-- `union`. Duplicate rows are eliminated.

372+union

373+ :: Query outer commons schemas params columns

374+ -> Query outer commons schemas params columns

375+ -> Query outer commons schemas params columns

376+q1 `union` q2 = UnsafeQuery $

377+ parenthesized (renderSQL q1)

378+ <+> "UNION"

379+ <+> parenthesized (renderSQL q2)

380+

381+-- | The results of two queries can be combined using the set operation

382+-- `unionAll`, the disjoint union. Duplicate rows are retained.

383+unionAll

384+ :: Query outer commons schemas params columns

385+ -> Query outer commons schemas params columns

386+ -> Query outer commons schemas params columns

387+q1 `unionAll` q2 = UnsafeQuery $

388+ parenthesized (renderSQL q1)

389+ <+> "UNION" <+> "ALL"

390+ <+> parenthesized (renderSQL q2)

391+

392+-- | The results of two queries can be combined using the set operation

393+-- `intersect`, the intersection. Duplicate rows are eliminated.

394+intersect

395+ :: Query outer commons schemas params columns

396+ -> Query outer commons schemas params columns

397+ -> Query outer commons schemas params columns

398+q1 `intersect` q2 = UnsafeQuery $

399+ parenthesized (renderSQL q1)

400+ <+> "INTERSECT"

401+ <+> parenthesized (renderSQL q2)

402+

403+-- | The results of two queries can be combined using the set operation

404+-- `intersectAll`, the intersection. Duplicate rows are retained.

405+intersectAll

406+ :: Query outer commons schemas params columns

407+ -> Query outer commons schemas params columns

408+ -> Query outer commons schemas params columns

409+q1 `intersectAll` q2 = UnsafeQuery $

410+ parenthesized (renderSQL q1)

411+ <+> "INTERSECT" <+> "ALL"

412+ <+> parenthesized (renderSQL q2)

413+

414+-- | The results of two queries can be combined using the set operation

415+-- `except`, the set difference. Duplicate rows are eliminated.

416+except

417+ :: Query outer commons schemas params columns

418+ -> Query outer commons schemas params columns

419+ -> Query outer commons schemas params columns

420+q1 `except` q2 = UnsafeQuery $

421+ parenthesized (renderSQL q1)

422+ <+> "EXCEPT"

423+ <+> parenthesized (renderSQL q2)

424+

425+-- | The results of two queries can be combined using the set operation

426+-- `exceptAll`, the set difference. Duplicate rows are retained.

427+exceptAll

428+ :: Query outer commons schemas params columns

429+ -> Query outer commons schemas params columns

430+ -> Query outer commons schemas params columns

431+q1 `exceptAll` q2 = UnsafeQuery $

432+ parenthesized (renderSQL q1)

433+ <+> "EXCEPT" <+> "ALL"

434+ <+> parenthesized (renderSQL q2)

435+

436+{-----------------------------------------

437+SELECT queries

438+-----------------------------------------}

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+

525+-- | the `TableExpression` in the `select` command constructs an intermediate

526+-- virtual table by possibly combining tables, views, eliminating rows,

527+-- grouping, etc. This table is finally passed on to processing by

528+-- the select list. The `Selection` determines which columns of

529+-- the intermediate table are actually output.

530+select

531+ :: (SListI row, row ~ (x ': xs))

532+ => Selection outer commons grp schemas params from row

533+ -- ^ selection

534+ -> TableExpression outer commons grp schemas params from

535+ -- ^ intermediate virtual table

536+ -> Query outer commons schemas params row

537+select selection tabexpr = UnsafeQuery $

538+ "SELECT"

539+ <+> renderSQL selection

540+ <+> renderSQL tabexpr

541+

542+-- | Like `select` but takes an `NP` list of `Expression`s instead

543+-- of a general `Selection`.

544+select_

545+ :: (SListI row, row ~ (x ': xs))

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

547+ -- ^ select list

548+ -> TableExpression outer commons grp schemas params from

549+ -- ^ intermediate virtual table

550+ -> Query outer commons schemas params row

551+select_ = select . List

552+

553+-- | After the select list has been processed, the result table can

554+-- be subject to the elimination of duplicate rows using `selectDistinct`.

555+selectDistinct

556+ :: (SListI columns, columns ~ (col ': cols))

557+ => Selection outer commons grp schemas params from columns

558+ -- ^ selection

559+ -> TableExpression outer commons grp schemas params from

560+ -- ^ intermediate virtual table

561+ -> Query outer commons schemas params columns

562+selectDistinct selection tabexpr = UnsafeQuery $

563+ "SELECT DISTINCT"

564+ <+> renderSQL selection

565+ <+> renderSQL tabexpr

566+

567+-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead

568+-- of a general `Selection`.

569+selectDistinct_

570+ :: (SListI columns, columns ~ (col ': cols))

571+ => NP (Aliased (Expression outer commons grp schemas params from)) columns

572+ -- ^ select list

573+ -> TableExpression outer commons grp schemas params from

574+ -- ^ intermediate virtual table

575+ -> Query outer commons schemas params columns

576+selectDistinct_ = selectDistinct . List

577+

578+{-|

579+`selectDistinctOn` keeps only the first row of each set of rows where

580+the given expressions evaluate to equal. The DISTINCT ON expressions are

581+interpreted using the same rules as for ORDER BY. ORDER BY is used to

582+ensure that the desired row appears first.

583+

584+The DISTINCT ON expression(s) must match the leftmost ORDER BY expression(s).

585+The ORDER BY clause will normally contain additional expression(s) that

586+determine the desired precedence of rows within each DISTINCT ON group.

587+

588+In order to guarantee they match and reduce redundancy, this function

589+will prepend the The DISTINCT ON expressions to the ORDER BY clause.

590+-}

591+selectDistinctOn

592+ :: (SListI columns, columns ~ (col ': cols))

593+ => [SortExpression outer commons grp schemas params from]

594+ -- ^ DISTINCT ON expression(s) and prepended to ORDER BY clause

595+ -> Selection outer commons grp schemas params from columns

596+ -- ^ selection

597+ -> TableExpression outer commons grp schemas params from

598+ -- ^ intermediate virtual table

599+ -> Query outer commons schemas params columns

600+selectDistinctOn distincts selection tab = UnsafeQuery $

601+ "SELECT DISTINCT ON"

602+ <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))

603+ <+> renderSQL selection

604+ <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})

605+ where

606+ renderDistinctOn = \case

607+ Asc expression -> renderSQL expression

608+ Desc expression -> renderSQL expression

609+ AscNullsFirst expression -> renderSQL expression

610+ DescNullsFirst expression -> renderSQL expression

611+ AscNullsLast expression -> renderSQL expression

612+ DescNullsLast expression -> renderSQL expression

613+

614+-- | Like `selectDistinctOn` but takes an `NP` list of `Expression`s instead

615+-- of a general `Selection`.

616+selectDistinctOn_

617+ :: (SListI columns, columns ~ (col ': cols))

618+ => [SortExpression outer commons grp schemas params from]

619+ -- ^ distinct on and return the first row in ordering

620+ -> NP (Aliased (Expression outer commons grp schemas params from)) columns

621+ -- ^ selection

622+ -> TableExpression outer commons grp schemas params from

623+ -- ^ intermediate virtual table

624+ -> Query outer commons schemas params columns

625+selectDistinctOn_ distincts = selectDistinctOn distincts . List

626+

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 []

665+

666+{-----------------------------------------

667+Table Expressions

668+-----------------------------------------}

669+

670+-- | A `TableExpression` computes a table. The table expression contains

671+-- a `fromClause` that is optionally followed by a `whereClause`,

672+-- `groupByClause`, `havingClause`, `orderByClause`, `limitClause`

673+-- and `offsetClause`s. Trivial table expressions simply refer

674+-- to a table on disk, a so-called base table, but more complex expressions

675+-- can be used to modify or combine base tables in various ways.

676+data TableExpression

677+ (outer :: FromType)

678+ (commons :: FromType)

679+ (grp :: Grouping)

680+ (schemas :: SchemasType)

681+ (params :: [NullityType])

682+ (from :: FromType)

683+ = TableExpression

684+ { fromClause :: FromClause outer commons schemas params from

685+ -- ^ A table reference that can be a table name, or a derived table such

686+ -- as a subquery, a @JOIN@ construct, or complex combinations of these.

687+ , whereClause :: [Condition outer commons 'Ungrouped schemas params from]

688+ -- ^ optional search coditions, combined with `.&&`. After the processing

689+ -- of the `fromClause` is done, each row of the derived virtual table

690+ -- is checked against the search condition. If the result of the

691+ -- condition is true, the row is kept in the output table,

692+ -- otherwise it is discarded. The search condition typically references

693+ -- at least one column of the table generated in the `fromClause`;

694+ -- this is not required, but otherwise the WHERE clause will

695+ -- be fairly useless.

696+ , groupByClause :: GroupByClause grp from

697+ -- ^ The `groupByClause` is used to group together those rows in a table

698+ -- that have the same values in all the columns listed. The order in which

699+ -- the columns are listed does not matter. The effect is to combine each

700+ -- set of rows having common values into one group row that represents all

701+ -- rows in the group. This is done to eliminate redundancy in the output

702+ -- and/or compute aggregates that apply to these groups.

703+ , havingClause :: HavingClause outer commons grp schemas params from

704+ -- ^ If a table has been grouped using `groupBy`, but only certain groups

705+ -- are of interest, the `havingClause` can be used, much like a

706+ -- `whereClause`, to eliminate groups from the result. Expressions in the

707+ -- `havingClause` can refer both to grouped expressions and to ungrouped

708+ -- expressions (which necessarily involve an aggregate function).

709+ , orderByClause :: [SortExpression outer commons grp schemas params from]

710+ -- ^ The `orderByClause` is for optional sorting. When more than one

711+ -- `SortExpression` is specified, the later (right) values are used to sort

712+ -- rows that are equal according to the earlier (left) values.

713+ , limitClause :: [Word64]

714+ -- ^ The `limitClause` is combined with `min` to give a limit count

715+ -- if nonempty. If a limit count is given, no more than that many rows

716+ -- will be returned (but possibly fewer, if the query itself yields

717+ -- fewer rows).

718+ , offsetClause :: [Word64]

719+ -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count

720+ -- if nonempty. The offset count says to skip that many rows before

721+ -- beginning to return rows. The rows are skipped before the limit count

722+ -- is applied.

723+ } deriving (GHC.Generic)

724+

725+-- | Render a `TableExpression`

726+instance RenderSQL (TableExpression outer commons grp schemas params from) where

727+ renderSQL

728+ (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat

729+ [ "FROM ", renderSQL frm'

730+ , renderWheres whs'

731+ , renderSQL grps'

732+ , renderSQL hvs'

733+ , renderOrderByClause srts'

734+ , renderLimits lims'

735+ , renderOffsets offs' ]

736+ where

737+ renderWheres = \case

738+ [] -> ""

739+ wh:[] -> " WHERE" <+> renderSQL wh

740+ wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)

741+ renderOrderByClause = \case

742+ [] -> ""

743+ srts -> " ORDER BY"

744+ <+> commaSeparated (renderSQL <$> srts)

745+ renderLimits = \case

746+ [] -> ""

747+ lims -> " LIMIT" <+> fromString (show (minimum lims))

748+ renderOffsets = \case

749+ [] -> ""

750+ offs -> " OFFSET" <+> fromString (show (sum offs))

751+

752+-- | A `from` generates a `TableExpression` from a table reference that can be

753+-- a table name, or a derived table such as a subquery, a JOIN construct,

754+-- or complex combinations of these. A `from` may be transformed by `where_`,

755+-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator

756+-- to match the left-to-right sequencing of their placement in SQL.

757+from

758+ :: FromClause outer commons schemas params from -- ^ table reference

759+ -> TableExpression outer commons 'Ungrouped schemas params from

760+from tab = TableExpression tab [] noGroups NoHaving [] [] []

761+

762+-- | A `where_` is an endomorphism of `TableExpression`s which adds a

763+-- search condition to the `whereClause`.

764+where_

765+ :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition

766+ -> TableExpression outer commons grp schemas params from

767+ -> TableExpression outer commons grp schemas params from

768+where_ wh rels = rels {whereClause = wh : whereClause rels}

769+

770+-- | A `groupBy` is a transformation of `TableExpression`s which switches

771+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform

772+-- a "grand total" aggregation query.

773+groupBy

774+ :: SListI bys

775+ => NP (By from) bys -- ^ grouped columns

776+ -> TableExpression outer commons 'Ungrouped schemas params from

777+ -> TableExpression outer commons ('Grouped bys) schemas params from

778+groupBy bys rels = TableExpression

779+ { fromClause = fromClause rels

780+ , whereClause = whereClause rels

781+ , groupByClause = group bys

782+ , havingClause = Having []

783+ , orderByClause = []

784+ , limitClause = limitClause rels

785+ , offsetClause = offsetClause rels

786+ }

787+

788+-- | A `having` is an endomorphism of `TableExpression`s which adds a

789+-- search condition to the `havingClause`.

790+having

791+ :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition

792+ -> TableExpression outer commons ('Grouped bys) schemas params from

793+ -> TableExpression outer commons ('Grouped bys) schemas params from

794+having hv rels = rels

795+ { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }

796+

797+instance OrderBy TableExpression where

798+ orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}

799+

800+-- | A `limit` is an endomorphism of `TableExpression`s which adds to the

801+-- `limitClause`.

802+limit

803+ :: Word64 -- ^ limit parameter

804+ -> TableExpression outer commons grp schemas params from

805+ -> TableExpression outer commons grp schemas params from

806+limit lim rels = rels {limitClause = lim : limitClause rels}

807+

808+-- | An `offset` is an endomorphism of `TableExpression`s which adds to the

809+-- `offsetClause`.

810+offset

811+ :: Word64 -- ^ offset parameter

812+ -> TableExpression outer commons grp schemas params from

813+ -> TableExpression outer commons grp schemas params from

814+offset off rels = rels {offsetClause = off : offsetClause rels}

815+

816+{-----------------------------------------

817+FROM clauses

818+-----------------------------------------}

819+

820+{- |

821+A `FromClause` can be a table name, or a derived table such

822+as a subquery, a @JOIN@ construct, or complex combinations of these.

823+-}

824+newtype FromClause outer commons schemas params from

825+ = UnsafeFromClause { renderFromClause :: ByteString }

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

827+instance RenderSQL (FromClause outer commons schemas params from) where

828+ renderSQL = renderFromClause

829+

830+-- | A real `table` is a table from the database.

831+table

832+ :: (Has sch schemas schema, Has tab schema ('Table table))

833+ => Aliased (QualifiedAlias sch) (alias ::: tab)

834+ -> FromClause outer commons schemas params '[alias ::: TableToRow table]

835+table (tab `As` alias) = UnsafeFromClause $

836+ renderSQL tab <+> "AS" <+> renderSQL alias

837+

838+-- | `subquery` derives a table from a `Query`.

839+subquery

840+ :: Aliased (Query outer commons schemas params) query

841+ -> FromClause outer commons schemas params '[query]

842+subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)

843+

844+-- | `view` derives a table from a `View`.

845+view

846+ :: (Has sch schemas schema, Has vw schema ('View view))

847+ => Aliased (QualifiedAlias sch) (alias ::: vw)

848+ -> FromClause outer commons schemas params '[alias ::: view]

849+view (vw `As` alias) = UnsafeFromClause $

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+{- |

865+@left & crossJoin right@. For every possible combination of rows from

866+@left@ and @right@ (i.e., a Cartesian product), the joined table will contain

867+a row consisting of all columns in @left@ followed by all columns in @right@.

868+If the tables have @n@ and @m@ rows respectively, the joined table will

869+have @n * m@ rows.

870+-}

871+crossJoin

872+ :: FromClause outer commons schemas params right

873+ -- ^ right

874+ -> FromClause outer commons schemas params left

875+ -- ^ left

876+ -> FromClause outer commons schemas params (Join left right)

877+crossJoin right left = UnsafeFromClause $

878+ renderSQL left <+> "CROSS JOIN" <+> renderSQL right

879+

880+{- | @left & innerJoin right on@. The joined table is filtered by

881+the @on@ condition.

882+-}

883+innerJoin

884+ :: FromClause outer commons schemas params right

885+ -- ^ right

886+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

887+ -- ^ @on@ condition

888+ -> FromClause outer commons schemas params left

889+ -- ^ left

890+ -> FromClause outer commons schemas params (Join left right)

891+innerJoin right on left = UnsafeFromClause $

892+ renderSQL left <+> "INNER JOIN" <+> renderSQL right

893+ <+> "ON" <+> renderSQL on

894+

895+{- | @left & leftOuterJoin right on@. First, an inner join is performed.

896+ Then, for each row in @left@ that does not satisfy the @on@ condition with

897+ any row in @right@, a joined row is added with null values in columns of @right@.

898+ Thus, the joined table always has at least one row for each row in @left@.

899+-}

900+leftOuterJoin

901+ :: FromClause outer commons schemas params right

902+ -- ^ right

903+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

904+ -- ^ @on@ condition

905+ -> FromClause outer commons schemas params left

906+ -- ^ left

907+ -> FromClause outer commons schemas params (Join left (NullifyFrom right))

908+leftOuterJoin right on left = UnsafeFromClause $

909+ renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right

910+ <+> "ON" <+> renderSQL on

911+

912+{- | @left & rightOuterJoin right on@. First, an inner join is performed.

913+ Then, for each row in @right@ that does not satisfy the @on@ condition with

914+ any row in @left@, a joined row is added with null values in columns of @left@.

915+ This is the converse of a left join: the result table will always

916+ have a row for each row in @right@.

917+-}

918+rightOuterJoin

919+ :: FromClause outer commons schemas params right

920+ -- ^ right

921+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

922+ -- ^ @on@ condition

923+ -> FromClause outer commons schemas params left

924+ -- ^ left

925+ -> FromClause outer commons schemas params (Join (NullifyFrom left) right)

926+rightOuterJoin right on left = UnsafeFromClause $

927+ renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right

928+ <+> "ON" <+> renderSQL on

929+

930+{- | @left & fullOuterJoin right on@. First, an inner join is performed.

931+ Then, for each row in @left@ that does not satisfy the @on@ condition with

932+ any row in @right@, a joined row is added with null values in columns of @right@.

933+ Also, for each row of @right@ that does not satisfy the join condition

934+ with any row in @left@, a joined row with null values in the columns of @left@

935+ is added.

936+-}

937+fullOuterJoin

938+ :: FromClause outer commons schemas params right

939+ -- ^ right

940+ -> Condition outer commons 'Ungrouped schemas params (Join left right)

941+ -- ^ @on@ condition

942+ -> FromClause outer commons schemas params left

943+ -- ^ left

944+ -> FromClause outer commons schemas params

945+ (Join (NullifyFrom left) (NullifyFrom right))

946+fullOuterJoin right on left = UnsafeFromClause $

947+ renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right

948+ <+> "ON" <+> renderSQL on

949+

950+{-----------------------------------------

951+Grouping

952+-----------------------------------------}

953+

954+-- | `By`s are used in `groupBy` to reference a list of columns which are then

955+-- used to group together those rows in a table that have the same values

956+-- in all the columns listed. @By \#col@ will reference an unambiguous

957+-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table

958+-- qualified column @tab.col@.

959+data By

960+ (from :: FromType)

961+ (by :: (Symbol,Symbol)) where

962+ By1

963+ :: (HasUnique table from columns, Has column columns ty)

964+ => Alias column

965+ -> By from '(table, column)

966+ By2

967+ :: (Has table from columns, Has column columns ty)

968+ => Alias table

969+ -> Alias column

970+ -> By from '(table, column)

971+deriving instance Show (By from by)

972+deriving instance Eq (By from by)

973+deriving instance Ord (By from by)

974+instance RenderSQL (By from by) where

975+ renderSQL = \case

976+ By1 column -> renderSQL column

977+ By2 rel column -> renderSQL rel <> "." <> renderSQL column

978+

979+instance (HasUnique rel rels cols, Has col cols ty, by ~ '(rel, col))

980+ => IsLabel col (By rels by) where fromLabel = By1 fromLabel

981+instance (HasUnique rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

982+ => IsLabel col (NP (By rels) bys) where fromLabel = By1 fromLabel :* Nil

983+instance (Has rel rels cols, Has col cols ty, by ~ '(rel, col))

984+ => IsQualified rel col (By rels by) where (!) = By2

985+instance (Has rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])

986+ => IsQualified rel col (NP (By rels) bys) where

987+ rel ! col = By2 rel col :* Nil

988+

989+-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.

990+-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.

991+-- @NoGroups@ is distinguised from @Group Nil@ since no aggregation can be

992+-- done on @NoGroups@ while all output `Expression`s must be aggregated

993+-- in @Group Nil@. In general, all output `Expression`s in the

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)

998+instance RenderSQL (GroupByClause grp from) where

999+ renderSQL = renderGroupByClause

1000+noGroups :: GroupByClause 'Ungrouped from

1001+noGroups = UnsafeGroupByClause ""

1002+group

1003+ :: SListI bys

1004+ => NP (By from) bys

1005+ -> GroupByClause ('Grouped bys) from

1006+group bys = UnsafeGroupByClause $ case bys of

1007+ Nil -> ""

1008+ bys' -> " GROUP BY" <+> renderCommaSeparated renderSQL bys'

1009+

1010+-- | A `HavingClause` is used to eliminate groups that are not of interest.

1011+-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`

1012+-- `TableExpression` must use `Having` whose conditions are combined with

1013+-- `.&&`.

1014+data HavingClause outer commons grp schemas params from where

1015+ NoHaving :: HavingClause outer commons 'Ungrouped schemas params from

1016+ Having

1017+ :: [Condition outer commons ('Grouped bys) schemas params from]

1018+ -> HavingClause outer commons ('Grouped bys) schemas params from

1019+deriving instance Show (HavingClause outer commons grp schemas params from)

1020+deriving instance Eq (HavingClause outer commons grp schemas params from)

1021+deriving instance Ord (HavingClause outer commons grp schemas params from)

1022+

1023+-- | Render a `HavingClause`.

1024+instance RenderSQL (HavingClause outer commons grp schemas params from) where

1025+ renderSQL = \case

1026+ NoHaving -> ""

1027+ Having [] -> ""

1028+ Having conditions ->

1029+ " HAVING" <+> commaSeparated (renderSQL <$> conditions)

1030+

1031+-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.

1032+data CommonTableExpression statement

1033+ (schemas :: SchemasType)

1034+ (params :: [NullityType])

1035+ (commons0 :: FromType)

1036+ (commons1 :: FromType) where

1037+ CommonTableExpression

1038+ :: Aliased (statement commons schemas params) (cte ::: common)

1039+ -> CommonTableExpression statement schemas params commons (cte ::: common ': commons)

1040+instance

1041+ ( KnownSymbol cte

1042+ , commons1 ~ (cte ::: common ': commons)

1043+ ) => Aliasable cte

1044+ (statement commons schemas params common)

1045+ (CommonTableExpression statement schemas params commons commons1) where

1046+ statement `as` cte = CommonTableExpression (statement `as` cte)

1047+instance

1048+ ( KnownSymbol cte

1049+ , commons1 ~ (cte ::: common ': commons)

1050+ ) => Aliasable cte

1051+ (statement commons schemas params common)

1052+ (Path (CommonTableExpression statement schemas params) commons commons1) where

1053+ statement `as` cte = csingleton (statement `as` cte)

1054+

1055+instance (forall c s p r. RenderSQL (statement c s p r)) => RenderSQL

1056+ (CommonTableExpression statement schemas params commons0 commons1) where

1057+ renderSQL (CommonTableExpression (statement `As` cte)) =

1058+ renderSQL cte <+> "AS" <+> parenthesized (renderSQL statement)

1059+

1060+-- | `with` provides a way to write auxiliary statements for use in a larger query.

1061+-- These statements, referred to as `CommonTableExpression`s, can be thought of as

1062+-- defining temporary tables that exist just for one query.

1063+class With statement where

1064+ with

1065+ :: Path (CommonTableExpression statement schemas params) commons0 commons1

1066+ -- ^ common table expressions

1067+ -> statement commons1 schemas params row

1068+ -- ^ larger query

1069+ -> statement commons0 schemas params row

1070+instance With (Query outer) where

1071+ with Done query = query

1072+ with ctes query = UnsafeQuery $

1073+ "WITH" <+> commaSeparated (ctoList renderSQL ctes) <+> renderSQL query

1074+

1075+{- |

1076+>>> import Data.Monoid (Sum (..))

1077+>>> import Data.Int (Int64)

1078+>>> :{

1079+ let

1080+ query :: Query_ schema () (Sum Int64)

1081+ query = withRecursive

1082+ ( values_ ((1 & astype int) `as` #n)

1083+ `unionAll`

1084+ select_ ((#n + 1) `as` #n)

1085+ (from (common #t) & where_ (#n .< 100)) `as` #t )

1086+ ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))

1087+ in printSQL query

1088+:}

1089+WITH RECURSIVE "t" AS ((SELECT * FROM (VALUES ((1 :: int))) AS t ("n")) UNION ALL (SELECT ("n" + 1) AS "n" FROM "t" AS "t" WHERE ("n" < 100))) SELECT COALESCE(sum(ALL "n"), 0) AS "getSum" FROM "t" AS "t"

1090+-}

1091+withRecursive

1092+ :: Aliased (Query outer (recursive ': commons) schemas params) recursive

1093+ -> Query outer (recursive ': commons) schemas params row

1094+ -> Query outer commons schemas params row

1095+withRecursive (recursive `As` cte) query = UnsafeQuery $

1096+ "WITH RECURSIVE" <+> renderSQL cte

1097+ <+> "AS" <+> parenthesized (renderSQL recursive)

1098+ <+> renderSQL query

squeal-postgresql/src/Squeal/PostgreSQL/Render.hsnew file+145

@@ -0,0 +1,145 @@

1+{-|

2+Module: Squeal.PostgreSQL.Render

3+Description: Rendering helper functions

4+Copyright: (c) Eitan Chatav, 2017

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Rendering helper functions.

9+-}

10+

11+{-# LANGUAGE

12+ AllowAmbiguousTypes

13+ , ConstraintKinds

14+ , FlexibleContexts

15+ , LambdaCase

16+ , MagicHash

17+ , OverloadedStrings

18+ , PolyKinds

19+ , RankNTypes

20+ , ScopedTypeVariables

21+ , TypeApplications

22+#-}

23+

24+module Squeal.PostgreSQL.Render

25+ ( -- * Render

26+ RenderSQL (..)

27+ , printSQL

28+ , escape

29+ , parenthesized

30+ , bracketed

31+ , (<+>)

32+ , commaSeparated

33+ , doubleQuoted

34+ , singleQuotedText

35+ , singleQuotedUtf8

36+ , renderCommaSeparated

37+ , renderCommaSeparatedConstraint

38+ , renderCommaSeparatedMaybe

39+ , renderNat

40+ , renderSymbol

41+ ) where

42+

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

44+import Data.ByteString (ByteString)

45+import Data.Maybe (catMaybes)

46+import Data.Monoid ((<>))

47+import Data.Text (Text)

48+import Generics.SOP

49+import GHC.Exts

50+import GHC.TypeLits hiding (Text)

51+

52+import qualified Data.Text as Text

53+import qualified Data.Text.Encoding as Text

54+import qualified Data.ByteString as ByteString

55+import qualified Data.ByteString.Char8 as Char8

56+

57+-- | Parenthesize a `ByteString`.

58+parenthesized :: ByteString -> ByteString

59+parenthesized str = "(" <> str <> ")"

60+

61+-- | Square bracket a `ByteString`

62+bracketed :: ByteString -> ByteString

63+bracketed str = "[" <> str <> "]"

64+

65+-- | Concatenate two `ByteString`s with a space between.

66+(<+>) :: ByteString -> ByteString -> ByteString

67+infixr 7 <+>

68+str1 <+> str2 = str1 <> " " <> str2

69+

70+-- | Comma separate a list of `ByteString`s.

71+commaSeparated :: [ByteString] -> ByteString

72+commaSeparated = ByteString.intercalate ", "

73+

74+-- | Add double quotes around a `ByteString`.

75+doubleQuoted :: ByteString -> ByteString

76+doubleQuoted str = "\"" <> str <> "\""

77+

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+

87+-- | Comma separate the renderings of a heterogeneous list.

88+renderCommaSeparated

89+ :: SListI xs

90+ => (forall x. expression x -> ByteString)

91+ -> NP expression xs -> ByteString

92+renderCommaSeparated render

93+ = commaSeparated

94+ . hcollapse

95+ . hmap (K . render)

96+

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+

107+-- | Comma separate the `Maybe` renderings of a heterogeneous list, dropping

108+-- `Nothing`s.

109+renderCommaSeparatedMaybe

110+ :: SListI xs

111+ => (forall x. expression x -> Maybe ByteString)

112+ -> NP expression xs -> ByteString

113+renderCommaSeparatedMaybe render

114+ = commaSeparated

115+ . catMaybes

116+ . hcollapse

117+ . hmap (K . render)

118+

119+-- | Render a promoted `Nat`.

120+renderNat :: forall n. KnownNat n => ByteString

121+renderNat = fromString (show (natVal' (proxy# :: Proxy# n)))

122+

123+-- | Render a promoted `Symbol`.

124+renderSymbol :: forall s. KnownSymbol s => ByteString

125+renderSymbol = fromString (symbolVal' (proxy# :: Proxy# s))

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+559−125

@@ -1,162 +1,596 @@

1+{-|

2+Module: Squeal.PostgreSQL.Schema

3+Description: Embedding of PostgreSQL type and alias system

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

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.

12+-}

1{-# LANGUAGE

13{-# LANGUAGE

2− DataKinds

14+ AllowAmbiguousTypes

15+ , ConstraintKinds

16+ , DeriveAnyClass

17+ , DeriveGeneric

3 , FlexibleContexts

18 , FlexibleContexts

4 , FlexibleInstances

19 , FlexibleInstances

20+ , FunctionalDependencies

5 , GADTs

21 , GADTs

6− , MagicHash

22+ , LambdaCase

7− , MultiParamTypeClasses

8 , OverloadedStrings

23 , OverloadedStrings

9− , PolyKinds

24+ , QuantifiedConstraints

10 , RankNTypes

25 , RankNTypes

11 , ScopedTypeVariables

26 , ScopedTypeVariables

27+ , StandaloneDeriving

12 , TypeApplications

28 , TypeApplications

13− , TypeFamilies

29+ , TypeFamilyDependencies

30+ , TypeInType

14 , TypeOperators

31 , TypeOperators

32+ , UndecidableInstances

33+ , UndecidableSuperClasses

15#-}

34#-}

17module Squeal.PostgreSQL.Schema

36module Squeal.PostgreSQL.Schema

37+ ( -- * Postgres Types

18− ( PGType (..)

38+ PGType (..)

19− , PGNum (..)

20− , PGIntegral

21− , PGFloating

22− , (:::)

23− , Alias (Alias)

24− , renderAlias

25− , Aliased (As)

26− , renderAliased

27 , NullityType (..)

39 , NullityType (..)

28− , NullifyType

40+ , RowType

29− , NullifyColumns

41+ , FromType

30− , NullifyTables

42+ -- * Schema Types

31− , ColumnType (..)

43+ , ColumnType

32− , BaseType

44+ , ColumnsType

45+ , TableType

46+ , SchemumType (..)

47+ , IndexType (..)

48+ , FunctionType

49+ , OperatorType (..)

50+ , ReturnsType (..)

51+ , SchemaType

52+ , SchemasType

53+ , Public

54+ -- * Constraints

55+ , (:=>)

56+ , ColumnConstraint (..)

57+ , TableConstraint (..)

58+ , TableConstraints

59+ , Uniquely

60+ -- * Enumerated Labels

61+ , IsPGlabel (..)

62+ , PGlabel (..)

63+ -- * Data Definitions

33 , Create

64 , Create

65+ , CreateIfNotExists

66+ , CreateOrReplace

34 , Drop

67 , Drop

68+ , DropSchemum

69+ , DropIfExists

70+ , DropSchemumIfExists

35 , Alter

71 , Alter

72+ , AlterIfExists

36 , Rename

73 , Rename

37− , Join

74+ , RenameIfExists

38− , Grouping (..)

75+ , ConstraintInvolves

39− , IsTableColumn (..)

76+ , DropIfConstraintsInvolve

40− , module GHC.OverloadedLabels

77+ , IsNotElem

41− , module GHC.TypeLits

78+ , AllUnique

79+ -- * Type Classifications

80+ , PGNum

81+ , PGIntegral

82+ , PGFloating

83+ , PGTypeOf

84+ , PGJsonType

85+ , PGJsonKey

86+ , SamePGType

87+ , AllNotNull

88+ , NotAllNull

89+ -- * Nullifications

90+ , NullifyType

91+ , NullifyRow

92+ , NullifyFrom

93+ -- * Table Conversions

94+ , TableToColumns

95+ , ColumnsToRow

96+ , TableToRow

42 ) where

97 ) where

44−import Data.ByteString

99+import Control.Category

100+import Data.Kind

45−import Data.Monoid

101+import Data.Monoid hiding (All)

46−import Data.String

102+import Data.Type.Bool

47−import GHC.OverloadedLabels

103+import Generics.SOP

48import GHC.TypeLits

104import GHC.TypeLits

105+import Prelude hiding (id, (.))

106+

107+import Squeal.PostgreSQL.Alias

108+import Squeal.PostgreSQL.List

109+import Squeal.PostgreSQL.Render

110

111+-- $setup

112+-- >>> import Squeal.PostgreSQL

113+

114+-- | `PGType` is the promoted datakind of PostgreSQL types.

115+--

116+-- >>> :kind 'PGbool

117+-- 'PGbool :: PGType

50data PGType

118data PGType

51− = PGbool

119+ = PGbool -- ^ logical Boolean (true/false)

52− | PGint2

120+ | PGint2 -- ^ signed two-byte integer

53− | PGint4

121+ | PGint4 -- ^ signed four-byte integer

54− | PGint8

122+ | PGint8 -- ^ signed eight-byte integer

55− | PGnumeric

123+ | PGnumeric -- ^ arbitrary precision numeric type

56− | PGfloat4

124+ | PGfloat4 -- ^ single precision floating-point number (4 bytes)

57− | PGfloat8

125+ | PGfloat8 -- ^ double precision floating-point number (8 bytes)

126+ | PGmoney -- ^ currency amount

58− | PGchar Nat

127+ | PGchar Nat -- ^ fixed-length character string

59− | PGvarchar Nat

128+ | PGvarchar Nat -- ^ variable-length character string

60− | PGtext

129+ | PGtext -- ^ variable-length character string

61− | PGbytea

130+ | PGbytea -- ^ binary data ("byte array")

62− | PGtimestamp

131+ | PGtimestamp -- ^ date and time (no time zone)

63− | PGtimestamptz

132+ | PGtimestamptz -- ^ date and time, including time zone

64− | PGdate

133+ | PGdate -- ^ calendar date (year, month, day)

65− | PGtime

134+ | PGtime -- ^ time of day (no time zone)

66− | PGtimetz

135+ | PGtimetz -- ^ time of day, including time zone

67− | PGinterval

136+ | PGinterval -- ^ time span

68− | PGuuid

137+ | PGuuid -- ^ universally unique identifier

69− | PGinet

138+ | PGinet -- ^ IPv4 or IPv6 host address

70− | PGjson

139+ | PGjson -- ^ textual JSON data

71− | PGjsonb

140+ | PGjsonb -- ^ binary JSON data, decomposed

72−

141+ | PGvararray NullityType -- ^ variable length array

73−class PGNum (ty :: PGType) where

142+ | PGfixarray [Nat] NullityType -- ^ fixed length array

74− decimal :: proxy ty -> Bool

143+ | PGenum [Symbol] -- ^ enumerated (enum) types are data types that comprise a static, ordered set of values.

75−instance PGNum 'PGint2 where decimal _ = False

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.

76−instance PGNum 'PGint4 where decimal _ = False

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.

77−instance PGNum 'PGint8 where decimal _ = False

146+ | PGtsquery -- ^ A tsquery value stores lexemes that are to be searched for.

78−instance PGNum 'PGnumeric where decimal _ = True

147+ | PGoid -- Object identifiers (OIDs) are used internally by PostgreSQL as primary keys for various system tables.

79−instance PGNum 'PGfloat4 where decimal _ = True

148+ | PGrange PGType -- ^ Range types are data types representing a range of values of some element type (called the range's subtype).

80−instance PGNum 'PGfloat8 where decimal _ = True

149+ | UnsafePGType Symbol -- ^ an escape hatch for unsupported PostgreSQL types

81−

150+

82−class PGNum ty => PGIntegral (ty :: PGType) where

151+-- | `NullityType` encodes the potential presence or definite absence of a

83−instance PGIntegral 'PGint2

152+-- @NULL@ allowing operations which are sensitive to such to be well typed.

84−instance PGIntegral 'PGint4

153+--

85−instance PGIntegral 'PGint8

154+-- >>> :kind 'Null 'PGint4

86−

155+-- 'Null 'PGint4 :: NullityType

87−class PGNum ty => PGFloating (ty :: PGType) where

156+-- >>> :kind 'NotNull ('PGvarchar 50)

88−instance PGFloating 'PGnumeric

157+-- 'NotNull ('PGvarchar 50) :: NullityType

89−instance PGFloating 'PGfloat4

158+data NullityType

90−instance PGFloating 'PGfloat8

159+ = Null PGType -- ^ @NULL@ may be present

91−

160+ | NotNull PGType -- ^ @NULL@ is absent

92−type (:::) (alias :: Symbol) (ty :: polykind) = '(alias,ty)

161+

93−

162+-- | The constraint operator, `:=>` is a type level pair

94−data Alias (alias :: Symbol) = Alias

163+-- between a "constraint" and some type, for use in pairing

95−

164+-- a `ColumnConstraint` with a `NullityType` to produce a `ColumnType`

96−renderAlias :: KnownSymbol alias => Alias alias -> ByteString

165+-- or a `TableConstraints` and a `ColumnsType` to produce a `TableType`.

97−renderAlias = fromString . symbolVal

166+type (:=>) constraint ty = '(constraint,ty)

98−

167+infixr 7 :=>

99−instance alias1 ~ alias2 => IsLabel alias1 (Alias alias2) where

168+

100− fromLabel = Alias

169+-- | `ColumnConstraint` encodes the availability of @DEFAULT@ for inserts and updates.

101−

170+-- A column can be assigned a default value.

102−data Aliased expression aliased where

171+-- A data `Squeal.PostgreSQL.Manipulations.Manipulation` command can also

103− As

172+-- request explicitly that a column be set to its default value,

104− :: KnownSymbol alias

173+-- without having to know what that value is.

105− => expression ty

174+data ColumnConstraint

106− -> Alias alias

175+ = Def -- ^ @DEFAULT@ is available for inserts and updates

107− -> Aliased expression (alias ::: ty)

176+ | NoDef -- ^ @DEFAULT@ is unavailable for inserts and updates

108−

177+

109−renderAliased

178+-- | `ColumnType` encodes the allowance of @DEFAULT@ and @NULL@ and the

110− :: (forall ty. expression ty -> ByteString)

179+-- base `PGType` for a column.

111− -> Aliased expression aliased

180+--

112− -> ByteString

181+-- >>> :set -XTypeFamilies -XTypeInType

113−renderAliased render (expression `As` alias) =

182+-- >>> import GHC.TypeLits

114− render expression <> " AS " <> renderAlias alias

183+-- >>> type family IdColumn :: ColumnType where IdColumn = 'Def :=> 'NotNull 'PGint4

115−

184+-- >>> type family EmailColumn :: ColumnType where EmailColumn = 'NoDef :=> 'Null 'PGtext

116−data NullityType = Null PGType | NotNull PGType

185+type ColumnType = (ColumnConstraint,NullityType)

117−

186+

118−data ColumnType = Optional NullityType | Required NullityType

187+-- | `ColumnsType` is a row of `ColumnType`s.

119−

188+--

189+-- >>> :{

190+-- type family UsersColumns :: ColumnsType where

191+-- UsersColumns =

192+-- '[ "name" ::: 'NoDef :=> 'NotNull 'PGtext

193+-- , "id" ::: 'Def :=> 'NotNull 'PGint4

194+-- ]

195+-- :}

196+type ColumnsType = [(Symbol,ColumnType)]

197+

198+-- | `TableConstraint` encodes various forms of data constraints

199+-- of columns in a table.

200+-- `TableConstraint`s give you as much control over the data in your tables

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

202+-- violate a constraint, an error is raised. This applies

203+-- even if the value came from the default value definition.

204+data TableConstraint

205+ = Check [Symbol]

206+ | Unique [Symbol]

207+ | PrimaryKey [Symbol]

208+ | ForeignKey [Symbol] Symbol [Symbol]

209+

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+-}

217+type TableConstraints = [(Symbol,TableConstraint)]

218+

219+-- | A `ForeignKey` must reference columns that either are

220+-- a `PrimaryKey` or form a `Unique` constraint.

221+type family Uniquely

222+ (key :: [Symbol])

223+ (constraints :: TableConstraints) :: Constraint where

224+ Uniquely key (uq ::: 'Unique key ': constraints) = ()

225+ Uniquely key (pk ::: 'PrimaryKey key ': constraints) = ()

226+ Uniquely key (_ ': constraints) = Uniquely key constraints

227+

228+-- | `TableType` encodes a row of constraints on a table as well as the types

229+-- of its columns.

230+--

231+-- >>> :{

232+-- type family UsersTable :: TableType where

233+-- UsersTable =

234+-- '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>

235+-- '[ "id" ::: 'Def :=> 'NotNull 'PGint4

236+-- , "name" ::: 'NoDef :=> 'NotNull 'PGtext

237+-- ]

238+-- :}

239+type TableType = (TableConstraints,ColumnsType)

240+

241+{- | A `RowType` is a row of `NullityType`. They correspond to Haskell

242+record types by means of `Squeal.PostgreSQL.Binary.RowPG` and are used in many places.

243+

244+>>> :{

245+type family PersonRow :: RowType where

246+ PersonRow =

247+ '[ "name" ::: 'NotNull 'PGtext

248+ , "age" ::: 'NotNull 'PGint4

249+ , "dateOfBirth" ::: 'Null 'PGdate

250+ ]

251+:}

252+-}

253+type RowType = [(Symbol,NullityType)]

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+

261+-- | `ColumnsToRow` removes column constraints.

262+type family ColumnsToRow (columns :: ColumnsType) :: RowType where

263+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': column5 ::: _ :=> ty5 ': columns) =

264+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': ColumnsToRow columns

265+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': column4 ::: _ :=> ty4 ': columns) =

266+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': ColumnsToRow columns

267+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': column3 ::: _ :=> ty3 ': columns) =

268+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': ColumnsToRow columns

269+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': column2 ::: _ :=> ty2 ': columns) =

270+ column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': ColumnsToRow columns

271+ ColumnsToRow (column ::: _ :=> ty ': column1 ::: _ :=> ty1 ': columns) =

272+ column ::: ty ': column1 ::: ty1 ': ColumnsToRow columns

273+ ColumnsToRow (column ::: _ :=> ty ': columns) =

274+ column ::: ty ': ColumnsToRow columns

275+ ColumnsToRow '[] = '[]

276+

277+-- | `TableToColumns` removes table constraints.

278+type family TableToColumns (table :: TableType) :: ColumnsType where

279+ TableToColumns (constraints :=> columns) = columns

280+

281+-- | Convert a table to a row type.

282+type family TableToRow (table :: TableType) :: RowType where

283+ TableToRow tab = ColumnsToRow (TableToColumns tab)

284+

285+-- | Numeric Postgres types.

286+type PGNum =

287+ '[ 'PGint2, 'PGint4, 'PGint8, 'PGnumeric, 'PGfloat4, 'PGfloat8]

288+

289+-- | Floating Postgres types.

290+type PGFloating = '[ 'PGfloat4, 'PGfloat8, 'PGnumeric]

291+

292+-- | Integral Postgres types.

293+type PGIntegral = '[ 'PGint2, 'PGint4, 'PGint8]

294+

295+-- | `PGTypeOf` forgets about @NULL@ and any column constraints.

120−type family BaseType (ty :: ColumnType) where

296+type family PGTypeOf (ty :: NullityType) :: PGType where

121− BaseType (optionality (nullity pg)) = pg

297+ PGTypeOf (nullity pg) = pg

122−

123−type family NullifyType (ty :: ColumnType) where

124− NullifyType (optionality ('Null ty)) = optionality ('Null ty)

125− NullifyType (optionality ('NotNull ty)) = optionality ('Null ty)

126−

127−type family NullifyColumns columns where

128− NullifyColumns '[] = '[]

129− NullifyColumns ((column ::: ty) ': columns) =

130− (column ::: NullifyType ty) ': NullifyColumns columns

131−

132−type family NullifyTables tables where

133− NullifyTables '[] = '[]

134− NullifyTables ((column ::: ty) ': columns) =

135− (column ::: NullifyColumns ty) ': NullifyTables columns

136

298

299+-- | Equality constraint on the underlying `PGType` of two columns.

300+class SamePGType

301+ (ty0 :: (Symbol,ColumnType)) (ty1 :: (Symbol,ColumnType)) where

302+instance ty0 ~ ty1 => SamePGType

303+ (alias0 ::: def0 :=> nullity0 ty0)

304+ (alias1 ::: def1 :=> nullity1 ty1)

305+

306+-- | `AllNotNull` is a constraint that proves a `ColumnsType` has no @NULL@s.

307+type 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

314+ AllNotNull '[] = ()

315+

316+-- | `NotAllNull` is a constraint that proves a `ColumnsType` has some

317+-- @NOT NULL@.

318+type family NotAllNull (columns :: ColumnsType) :: Constraint where

319+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

320+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

321+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

322+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

323+ NotAllNull (_ ::: _ :=> _ _ ': _ ::: _ :=> 'NotNull _ ': _) = ()

324+ NotAllNull (_ ::: _ :=> 'NotNull _ ': _) = ()

325+ NotAllNull (_ ::: _ :=> 'Null _ ': columns) = NotAllNull columns

326+

327+-- | `NullifyType` is an idempotent that nullifies a `NullityType`.

328+type family NullifyType (ty :: NullityType) :: NullityType where

329+ NullifyType ('Null ty) = 'Null ty

330+ NullifyType ('NotNull ty) = 'Null ty

331+

332+-- | `NullifyRow` is an idempotent that nullifies a `RowType`.

333+type family NullifyRow (columns :: RowType) :: RowType where

334+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': column5 ::: ty5 ': columns) =

335+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': column5 ::: NullifyType ty5 ': NullifyRow columns

336+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': column4 ::: ty4 ': columns) =

337+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': column4 ::: NullifyType ty4 ': NullifyRow columns

338+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': column3 ::: ty3 ': columns) =

339+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': column3 ::: NullifyType ty3 ': NullifyRow columns

340+ NullifyRow (column ::: ty ': column1 ::: ty1 ': column2 ::: ty2 ': columns) =

341+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': column2 ::: NullifyType ty2 ': NullifyRow columns

342+ NullifyRow (column ::: ty ': column1 ::: ty1 ': columns) =

343+ column ::: NullifyType ty ': column1 ::: NullifyType ty1 ': NullifyRow columns

344+ NullifyRow (column ::: ty ': columns) =

345+ column ::: NullifyType ty ': NullifyRow columns

346+ NullifyRow '[] = '[]

347+

348+-- | `NullifyFrom` is an idempotent that nullifies a `FromType`

349+-- used to nullify the left or right hand side of an outer join

350+-- in a `Squeal.PostgreSQL.Query.FromClause`.

351+type family NullifyFrom (tables :: FromType) :: FromType where

352+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': table5 ::: columns5 ': tables) =

353+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns5 ': table5 ::: NullifyRow columns4 ': NullifyFrom tables

354+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': table4 ::: columns4 ': tables) =

355+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': table4 ::: NullifyRow columns4 ': NullifyFrom tables

356+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': table3 ::: columns3 ': tables) =

357+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': table3 ::: NullifyRow columns3 ': NullifyFrom tables

358+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': table2 ::: columns2 ': tables) =

359+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': table2 ::: NullifyRow columns2 ': NullifyFrom tables

360+ NullifyFrom (table ::: columns ': table1 ::: columns1 ': tables) =

361+ table ::: NullifyRow columns ': table1 ::: NullifyRow columns1 ': NullifyFrom tables

362+ NullifyFrom (table ::: columns ': tables) =

363+ table ::: NullifyRow columns ': NullifyFrom tables

364+ NullifyFrom '[] = '[]

365+

366+-- | @Create alias x xs@ adds @alias ::: x@ to the end of @xs@ and is used in

367+-- `Squeal.PostgreSQL.Definition.createTable` statements and in @ALTER TABLE@

368+-- `Squeal.PostgreSQL.Definition.addColumn`.

137type family Create alias x xs where

369type family Create alias x xs where

138 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")

139 Create alias y (x ': xs) = x ': Create alias y xs

375 Create alias y (x ': xs) = x ': Create alias y xs

140

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+

394+-- | @Drop alias xs@ removes the type associated with @alias@ in @xs@

395+-- and is used in `Squeal.PostgreSQL.Definition.dropTable` statements

396+-- and in @ALTER TABLE@ `Squeal.PostgreSQL.Definition.dropColumn` statements.

141type 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" )

142− Drop alias ((alias ::: x) ': xs) = xs

402+ Drop alias (alias ::: x ': xs) = xs

143 Drop alias (x ': xs) = x ': Drop alias xs

403 Drop alias (x ': xs) = x ': Drop alias xs

144

404

145−type family Alter alias xs x where

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+

437+-- | @Alter alias x xs@ replaces the type associated with an @alias@ in @xs@

438+-- with the type @x@ and is used in `Squeal.PostgreSQL.Definition.alterTable`

439+-- and `Squeal.PostgreSQL.Definition.alterColumn`.

440+type family Alter alias x xs where

441+ Alter alias x '[] = TypeError

442+ ('Text "Alter: alias "

443+ ':<>: 'ShowType alias

444+ ':<>: 'Text " does not exist" )

146− Alter alias ((alias ::: x0) ': xs) x1 = (alias ::: x1) ': xs

445+ Alter alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

147− Alter alias (x0 ': xs) x1 = x0 ': Alter alias xs x1

446+ Alter alias x1 (x0 ': xs) = x0 ': Alter alias x1 xs

148

447

448+type family AlterIfExists alias x xs where

449+ AlterIfExists alias x '[] = '[]

450+ AlterIfExists alias x1 (alias ::: x0 ': xs) = alias ::: x1 ': xs

451+ AlterIfExists alias x1 (x0 ': xs) = x0 ': AlterIfExists alias x1 xs

452+

453+-- | @Rename alias0 alias1 xs@ replaces the alias @alias0@ by @alias1@ in @xs@

454+-- and is used in `Squeal.PostgreSQL.Definition.alterTableRename` and

455+-- `Squeal.PostgreSQL.Definition.renameColumn`.

149type 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" )

150 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

461 Rename alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

151 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

462 Rename alias0 alias1 (x ': xs) = x ': Rename alias0 alias1 xs

152

463

153−type family Join xs ys where

464+type family RenameIfExists alias0 alias1 xs where

154− Join '[] ys = ys

465+ RenameIfExists alias x '[] = '[]

155− Join (x ': xs) ys = x ': Join xs ys

466+ RenameIfExists alias0 alias1 ((alias0 ::: x0) ': xs) = (alias1 ::: x0) ': xs

467+ RenameIfExists alias0 alias1 (x ': xs) = x ': RenameIfExists alias0 alias1 xs

468+

469+-- | Check if a `TableConstraint` involves a column

470+type family ConstraintInvolves column constraint where

471+ ConstraintInvolves column ('Check columns) = column `Elem` columns

472+ ConstraintInvolves column ('Unique columns) = column `Elem` columns

473+ ConstraintInvolves column ('PrimaryKey columns) = column `Elem` columns

474+ ConstraintInvolves column ('ForeignKey columns tab refcolumns)

475+ = column `Elem` columns

476+

477+-- | Drop all `TableConstraint`s that involve a column

478+type family DropIfConstraintsInvolve column constraints where

479+ DropIfConstraintsInvolve column '[] = '[]

480+ DropIfConstraintsInvolve column (alias ::: constraint ': constraints)

481+ = If (ConstraintInvolves column constraint)

482+ (DropIfConstraintsInvolve column constraints)

483+ (alias ::: constraint ': DropIfConstraintsInvolve column constraints)

484+

485+-- | A `SchemumType` is a user-defined type, either a `Table`,

486+-- `View` or `Typedef`.

487+data SchemumType

488+ = Table TableType

489+ | View RowType

490+ | Typedef PGType

491+ | Index IndexType

492+ | Function FunctionType

493+ | Operator OperatorType

494+ | UnsafeSchemum Symbol

495+

496+type FunctionType = ([NullityType], ReturnsType)

497+

498+data IndexType

499+ = Btree

500+ | Hash

501+ | Gist

502+ | Spgist

503+ | Gin

504+ | Brin

505+

506+data ReturnsType

507+ = Returns NullityType

508+ | ReturnsTable RowType

509+

510+data OperatorType

511+ = BinaryOp NullityType NullityType NullityType

512+ | LeftOp NullityType NullityType

513+ | RightOp NullityType NullityType

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+-}

537+type SchemaType = [(Symbol,SchemumType)]

538+

539+{- |

540+A database contains one or more named schemas, which in turn contain tables.

541+The same object name can be used in different schemas without conflict;

542+for example, both schema1 and myschema can contain tables named mytable.

543+Unlike databases, schemas are not rigidly separated:

544+a user can access objects in any of the schemas in the database they are connected to,

545+if they have privileges to do so.

546+

547+There are several reasons why one might want to use schemas:

548+

549+ * To allow many users to use one database without interfering with each other.

550+ * To organize database objects into logical groups to make them more manageable.

551+ * Third-party applications can be put into separate schemas

552+ so they do not collide with the names of other objects.

553+-}

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

555+

556+-- | A type family to use for a single schema database.

557+type family Public (schema :: SchemaType) :: SchemasType

558+ where Public schema = '["public" ::: schema]

559+

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 ]

156

584

157−data Grouping

585+-- | Utility class for `AllUnique` to provide nicer error messages.

158− = Ungrouped

586+class IsNotElem x isElem where

159− | Grouped [(Symbol,Symbol)]

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

160

592

161−class IsTableColumn table column expression where

593+-- | No elem of @xs@ appears more than once, in the context of assignment.

162− (&.) :: Alias table -> Alias column -> expression

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/Statement.hsdeleted−1310

@@ -1,1310 +0,0 @@

1−{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}

2−{-# LANGUAGE

3− DataKinds

4− , FlexibleContexts

5− , FlexibleInstances

6− , FunctionalDependencies

7− , GADTs

8− , LambdaCase

9− , MagicHash

10− , OverloadedStrings

11− , PolyKinds

12− , RankNTypes

13− , ScopedTypeVariables

14− , TypeApplications

15− , TypeFamilies

16− , TypeOperators

17− , UndecidableInstances

18−#-}

19−

20−module Squeal.PostgreSQL.Statement where

21−

22−import Control.Category

23−import Data.ByteString (ByteString)

24−import Data.Foldable

25−import Data.Maybe

26−import Data.Monoid

27−import Data.Ratio

28−import Data.String

29−import Data.Word

30−import Generics.SOP

31−import GHC.Exts

32−import GHC.OverloadedLabels

33−import GHC.TypeLits

34−import Prelude hiding (RealFrac(..), id, (.))

35−

36−import qualified Data.ByteString as ByteString

37−

38−import Squeal.PostgreSQL.Schema

39−

40−{-----------------------------------------

41−column expressions

42−-----------------------------------------}

43−

44−newtype Expression

45− (params :: [ColumnType])

46− (tables :: [(Symbol,[(Symbol,ColumnType)])])

47− (grouping :: Grouping)

48− (ty :: ColumnType)

49− = UnsafeExpression { renderExpression :: ByteString }

50− deriving (Show,Eq)

51−

52−class (PGTyped (BaseType ty), KnownNat n)

53− => HasParameter (n :: Nat) params ty | n params -> ty where

54− param :: proxy n -> Expression params tables grouping ty

55− param _ = UnsafeExpression $ parenthesized $

56− "$" <> renderNat (Proxy @n) <+> "::"

57− <+> renderTypeExpression (pgtype @(BaseType ty))

58−instance {-# OVERLAPPING #-} PGTyped (BaseType ty1)

59− => HasParameter 1 (ty1:tys) ty1

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

61− => HasParameter n (ty' : params) ty

62−

63−class KnownSymbol column => HasColumn column columns ty

64− | column columns -> ty where

65− getColumn

66− :: Proxy# column

67− -> Expression params '[table ::: columns] 'Ungrouped ty

68− getColumn column = UnsafeExpression $ renderSymbol column

69−instance {-# OVERLAPPING #-} KnownSymbol column

70− => HasColumn column ((column ::: optionality ty) ': tys) ('Required ty)

71−instance {-# OVERLAPPABLE #-} (KnownSymbol column, HasColumn column table ty)

72− => HasColumn column (ty' ': table) ty

73−

74−instance (HasColumn column columns ty, tables ~ '[table ::: columns])

75− => IsLabel column (Expression params tables 'Ungrouped ty) where

76− fromLabel = getColumn (proxy# @Symbol @column)

77−

78−instance (HasTable table tables columns, HasColumn column columns ty)

79− => IsTableColumn table column (Expression params tables 'Ungrouped ty) where

80− table &. column = UnsafeExpression $

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

82−

83−def :: Expression params '[] grouping ('Optional (nullity ty))

84−def = UnsafeExpression "DEFAULT"

85−

86−unDef

87− :: Expression params '[] grouping ('Required (nullity ty))

88− -> Expression params '[] grouping ('Optional (nullity ty))

89−unDef = UnsafeExpression . renderExpression

90−

91−null :: Expression params tables grouping (optionality ('Null ty))

92−null = UnsafeExpression "NULL"

93−

94−unNull

95− :: Expression params tables grouping (optionality ('NotNull ty))

96− -> Expression params tables grouping (optionality ('Null ty))

97−unNull = UnsafeExpression . renderExpression

98−

99−coalesce

100− :: [Expression params tables grouping ('Required ('Null ty))]

101− -> Expression params tables grouping ('Required ('NotNull ty))

102− -> Expression params tables grouping ('Required ('NotNull ty))

103−coalesce nullxs notNullx = UnsafeExpression $

104− "COALESCE" <> parenthesized (commaSeparated

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

106−

107−fromNull

108− :: Expression params tables grouping ('Required ('NotNull ty))

109− -> Expression params tables grouping ('Required ('Null ty))

110− -> Expression params tables grouping ('Required ('NotNull ty))

111−fromNull notNullx nullx = coalesce [nullx] notNullx

112−

113−isNull

114− :: Expression params tables grouping ('Required ('Null ty))

115− -> Condition params tables grouping

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

117−

118−isn'tNull

119− :: Expression params tables grouping ('Required ('Null ty))

120− -> Condition params tables grouping

121−isn'tNull x = UnsafeExpression $ renderExpression x <+> "IS NOT NULL"

122−

123−matchNull

124− :: Expression params tables grouping ('Required nullty)

125− -> ( Expression params tables grouping ('Required ('NotNull ty))

126− -> Expression params tables grouping ('Required nullty) )

127− -> Expression params tables grouping ('Required ('Null ty))

128− -> Expression params tables grouping ('Required nullty)

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

130− (f (UnsafeExpression (renderExpression y)))

131−

132−nullIf

133− :: Expression params tables grouping ('Required ('NotNull ty))

134− -> Expression params tables grouping ('Required ('NotNull ty))

135− -> Expression params tables grouping ('Required ('Null ty))

136−nullIf x y = UnsafeExpression $ parenthesized $

137− renderExpression x <> ", " <> renderExpression y

138−

139−greatest

140− :: [Expression params tables grouping ('Required nullty)]

141− -> Expression params table grouping ('Required nullty)

142−greatest xs = UnsafeExpression $ "GREATEST("

143− <> commaSeparated (renderExpression <$> xs) <> ")"

144−

145−least

146− :: [Expression params tables grouping ('Required nullty)]

147− -> Expression params table grouping ('Required nullty)

148−least xs = UnsafeExpression $ "LEAST("

149− <> commaSeparated (renderExpression <$> xs) <> ")"

150−

151−unsafeBinaryOp

152− :: ByteString

153− -> Expression params tables grouping ('Required ty0)

154− -> Expression params tables grouping ('Required ty1)

155− -> Expression params tables grouping ('Required ty2)

156−unsafeBinaryOp op x y = UnsafeExpression $ parenthesized $

157− renderExpression x <+> op <+> renderExpression y

158−

159−unsafeUnaryOp

160− :: ByteString

161− -> Expression params tables grouping ('Required ty0)

162− -> Expression params tables grouping ('Required ty1)

163−unsafeUnaryOp op x = UnsafeExpression $ parenthesized $

164− op <+> renderExpression x

165−

166−unsafeFunction

167− :: ByteString

168− -> Expression params tables grouping ('Required xty)

169− -> Expression params tables grouping ('Required yty)

170−unsafeFunction fun x = UnsafeExpression $

171− fun <> parenthesized (renderExpression x)

172−

173−instance PGNum ty

174− => Num (Expression params tables grouping ('Required (nullity ty))) where

175− (+) = unsafeBinaryOp "+"

176− (-) = unsafeBinaryOp "-"

177− (*) = unsafeBinaryOp "*"

178− abs = unsafeFunction "abs"

179− signum = unsafeFunction "sign"

180− fromInteger

181− = UnsafeExpression

182− . (<> if decimal (Proxy :: Proxy ty) then "." else "")

183− . fromString

184− . show

185−

186−instance PGFloating ty => Fractional

187− (Expression params tables grouping ('Required (nullity ty))) where

188− (/) = unsafeBinaryOp "/"

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

190−

191−instance (PGFloating ty, PGTyped ty) => Floating

192− (Expression params tables grouping ('Required (nullity ty))) where

193− pi = UnsafeExpression "pi()"

194− exp = unsafeFunction "exp"

195− log = unsafeFunction "ln"

196− sqrt = unsafeFunction "sqrt"

197− b ** x = UnsafeExpression $

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

199− logBase b y = cast pgtype $ logBaseNumeric b y

200− where

201− logBaseNumeric

202− :: Expression params tables grouping ('Required (nullity ty))

203− -> Expression params tables grouping ('Required (nullity ty))

204− -> Expression params tables grouping ('Required (nullity 'PGnumeric))

205− logBaseNumeric b' y' = UnsafeExpression $ mconcat

206− [ "log("

207− , renderExpression (cast numeric b')

208− , ", "

209− , renderExpression (cast numeric y')

210− , ")"

211− ]

212− sin = unsafeFunction "sin"

213− cos = unsafeFunction "cos"

214− tan = unsafeFunction "tan"

215− asin = unsafeFunction "asin"

216− acos = unsafeFunction "acos"

217− atan = unsafeFunction "atan"

218− sinh x = (exp x - exp (-x)) / 2

219− cosh x = (exp x + exp (-x)) / 2

220− tanh x = sinh x / cosh x

221− asinh x = log (x + sqrt (x*x + 1))

222− acosh x = log (x + sqrt (x*x - 1))

223− atanh x = log ((1 + x) / (1 - x)) / 2

224−

225−atan2

226− :: PGFloating float

227− => Expression params tables grouping ('Required (nullity float))

228− -> Expression params tables grouping ('Required (nullity float))

229− -> Expression params tables grouping ('Required (nullity float))

230−atan2 y x = UnsafeExpression $

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

232−

233−cast

234− :: TypeExpression ('Required ('Null ty1))

235− -> Expression params tables grouping ('Required (nullity ty0))

236− -> Expression params tables grouping ('Required (nullity ty1))

237−cast ty x = UnsafeExpression $ parenthesized $

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

239−

240−div

241− :: PGIntegral int

242− => Expression params tables grouping ('Required (nullity int))

243− -> Expression params tables grouping ('Required (nullity int))

244− -> Expression params tables grouping ('Required (nullity int))

245−div = unsafeBinaryOp "/"

246−

247−mod

248− :: PGIntegral int

249− => Expression params tables grouping ('Required (nullity int))

250− -> Expression params tables grouping ('Required (nullity int))

251− -> Expression params tables grouping ('Required (nullity int))

252−mod = unsafeBinaryOp "%"

253−

254−trunc

255− :: PGFloating frac

256− => Expression params tables grouping ('Required (nullity frac))

257− -> Expression params tables grouping ('Required (nullity frac))

258−trunc = unsafeFunction "trunc"

259−

260−round_

261− :: PGFloating frac

262− => Expression params tables grouping ('Required (nullity frac))

263− -> Expression params tables grouping ('Required (nullity frac))

264−round_ = unsafeFunction "round"

265−

266−ceiling_

267− :: PGFloating frac

268− => Expression params tables grouping ('Required (nullity frac))

269− -> Expression params tables grouping ('Required (nullity frac))

270−ceiling_ = unsafeFunction "ceiling"

271−

272−instance IsString

273− (Expression params tables grouping ('Required (nullity 'PGtext))) where

274− fromString str = UnsafeExpression $

275− "E\'" <> fromString (escape =<< str) <> "\'"

276− where

277− escape = \case

278− '\NUL' -> "\\0"

279− '\'' -> "''"

280− '"' -> "\\\""

281− '\b' -> "\\b"

282− '\n' -> "\\n"

283− '\r' -> "\\r"

284− '\t' -> "\\t"

285− '\\' -> "\\\\"

286− c -> [c]

287−

288−type Condition params tables grouping =

289− Expression params tables grouping ('Required ('NotNull 'PGbool))

290−

291−true :: Condition params tables grouping

292−true = UnsafeExpression "TRUE"

293−

294−false :: Condition params tables grouping

295−false = UnsafeExpression "FALSE"

296−

297−not_

298− :: Condition params tables grouping

299− -> Condition params tables grouping

300−not_ = unsafeUnaryOp "NOT"

301−

302−(&&*)

303− :: Condition params tables grouping

304− -> Condition params tables grouping

305− -> Condition params tables grouping

306−(&&*) = unsafeBinaryOp "AND"

307−

308−(||*)

309− :: Condition params tables grouping

310− -> Condition params tables grouping

311− -> Condition params tables grouping

312−(||*) = unsafeBinaryOp "OR"

313−

314−caseWhenThenElse

315− :: [ ( Condition params tables grouping

316− , Expression params tables grouping ('Required ty)

317− ) ]

318− -> Expression params tables grouping ('Required ty)

319− -> Expression params tables grouping ('Required ty)

320−caseWhenThenElse whenThens else_ = UnsafeExpression $ mconcat

321− [ "CASE"

322− , mconcat

323− [ mconcat

324− [ " WHEN ", renderExpression when_

325− , " THEN ", renderExpression then_

326− ]

327− | (when_,then_) <- whenThens

328− ]

329− , " ELSE ", renderExpression else_

330− , " END"

331− ]

332−

333−ifThenElse

334− :: Condition params tables grouping

335− -> Expression params tables grouping ('Required ty)

336− -> Expression params tables grouping ('Required ty)

337− -> Expression params tables grouping ('Required ty)

338−ifThenElse if_ then_ else_ = caseWhenThenElse [(if_,then_)] else_

339−

340−(==*)

341− :: Expression params tables grouping ('Required (nullity ty))

342− -> Expression params tables grouping ('Required (nullity ty))

343− -> Expression params tables grouping ('Required (nullity 'PGbool))

344−(==*) = unsafeBinaryOp "="

345−

346−(/=*)

347− :: Expression params tables grouping ('Required (nullity ty))

348− -> Expression params tables grouping ('Required (nullity ty))

349− -> Expression params tables grouping ('Required (nullity 'PGbool))

350−(/=*) = unsafeBinaryOp "<>"

351−

352−(>=*)

353− :: Expression params tables grouping ('Required (nullity ty))

354− -> Expression params tables grouping ('Required (nullity ty))

355− -> Expression params tables grouping ('Required (nullity 'PGbool))

356−(>=*) = unsafeBinaryOp ">="

357−

358−(<*)

359− :: Expression params tables grouping ('Required (nullity ty))

360− -> Expression params tables grouping ('Required (nullity ty))

361− -> Expression params tables grouping ('Required (nullity 'PGbool))

362−(<*) = unsafeBinaryOp "<"

363−

364−(<=*)

365− :: Expression params tables grouping ('Required (nullity ty))

366− -> Expression params tables grouping ('Required (nullity ty))

367− -> Expression params tables grouping ('Required (nullity 'PGbool))

368−(<=*) = unsafeBinaryOp "<="

369−

370−(>*)

371− :: Expression params tables grouping ('Required (nullity ty))

372− -> Expression params tables grouping ('Required (nullity ty))

373− -> Expression params tables grouping ('Required (nullity 'PGbool))

374−(>*) = unsafeBinaryOp ">"

375−

376−data SortExpression params tables grouping where

377− Asc

378− :: Expression params tables grouping ty

379− -> SortExpression params tables grouping

380− Desc

381− :: Expression params tables grouping ty

382− -> SortExpression params tables grouping

383−

384−renderSortExpression :: SortExpression params tables grouping -> ByteString

385−renderSortExpression = \case

386− Asc expression -> renderExpression expression <+> "ASC"

387− Desc expression -> renderExpression expression <+> "DESC"

388−

389−{-----------------------------------------

390−aggregation

391−-----------------------------------------}

392−

393−data By

394− (tables :: [(Symbol,[(Symbol,ColumnType)])])

395− (tabcol :: (Symbol,Symbol)) where

396− By

397− :: (tables ~ '[table ::: columns], HasColumn column columns ty)

398− => Alias column

399− -> By tables '(table, column)

400− By2

401− :: (HasTable table tables columns, HasColumn column columns ty)

402− => (Alias table, Alias column)

403− -> By tables '(table, column)

404−

405−renderBy :: By tables tabcolty -> ByteString

406−renderBy = \case

407− By column -> renderAlias column

408− By2 (table, column) -> renderAlias table <> "." <> renderAlias column

409−

410−data GroupByClause tables grouping where

411− NoGroups :: GroupByClause tables 'Ungrouped

412− Group

413− :: SListI bys

414− => NP (By tables) bys

415− -> GroupByClause tables ('Grouped bys)

416−

417−renderGroupByClause :: GroupByClause tables grouping -> ByteString

418−renderGroupByClause = \case

419− NoGroups -> ""

420− Group Nil -> ""

421− Group bys -> " GROUP BY" <+> renderCommaSeparated renderBy bys

422−

423−data HavingClause params tables grouping where

424− NoHaving :: HavingClause params tables 'Ungrouped

425− Having

426− :: [Condition params tables ('Grouped bys)]

427− -> HavingClause params tables ('Grouped bys)

428−

429−renderHavingClause :: HavingClause params tables grouping -> ByteString

430−renderHavingClause = \case

431− NoHaving -> ""

432− Having [] -> ""

433− Having conditions ->

434− " HAVING" <+> commaSeparated (renderExpression <$> conditions)

435−

436−class (KnownSymbol table, KnownSymbol column)

437− => GroupedBy table column bys where

438− getGroup1

439− :: (tables ~ '[table ::: columns], HasColumn column columns ty)

440− => Proxy# column

441− -> Expression params tables ('Grouped bys) ty

442− getGroup1 column = UnsafeExpression $ renderSymbol column

443− getGroup2

444− :: (HasTable table tables columns, HasColumn column columns ty)

445− => Alias table

446− -> Alias column

447− -> Expression params tables ('Grouped bys) ty

448− getGroup2 table column = UnsafeExpression $

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

450−instance {-# OVERLAPPING #-} (KnownSymbol table, KnownSymbol column)

451− => GroupedBy table column ('(table,column) ': bys)

452−instance {-# OVERLAPPABLE #-}

453− ( KnownSymbol table

454− , KnownSymbol column

455− , GroupedBy table column bys

456− ) => GroupedBy table column (tabcol ': bys)

457−

458−instance

459− ( tables ~ '[table ::: columns]

460− , HasColumn column columns ty

461− , GroupedBy table column bys

462− ) => IsLabel column

463− (Expression params tables ('Grouped bys) ty) where

464− fromLabel = getGroup1 (proxy# @Symbol @column)

465−

466−instance

467− ( HasTable table tables columns

468− , HasColumn column columns ty

469− , GroupedBy table column bys

470− ) => IsTableColumn table column

471− (Expression params tables ('Grouped bys) ty) where (&.) = getGroup2

472−

473−unsafeAggregate

474− :: ByteString

475− -> Expression params tables 'Ungrouped ('Required xty)

476− -> Expression params tables ('Grouped bys) ('Required yty)

477−unsafeAggregate fun x = UnsafeExpression $ mconcat

478− [fun, "(", renderExpression x, ")"]

479−

480−sum_

481− :: PGNum ty

482− => Expression params tables 'Ungrouped ('Required (nullity ty))

483− -> Expression params tables ('Grouped bys) ('Required (nullity ty))

484−sum_ = unsafeAggregate "sum"

485−

486−avgInt

487− :: PGIntegral int

488− => Expression params tables 'Ungrouped ('Required (nullity int))

489− -> Expression params tables ('Grouped bys) ('Required (nullity 'PGnumeric))

490−avgInt = unsafeAggregate "avg"

491−

492−avgFloat

493− :: PGFloating float

494− => Expression params tables 'Ungrouped ('Required (nullity float))

495− -> Expression params tables ('Grouped bys) ('Required (nullity 'PGfloat8))

496−avgFloat = unsafeAggregate "avg"

497−

498−bitAnd

499− :: PGIntegral int

500− => Expression params tables 'Ungrouped ('Required (nullity int))

501− -> Expression params tables ('Grouped bys) ('Required (nullity int))

502−bitAnd = unsafeAggregate "bit_and"

503−

504−bitOr

505− :: PGIntegral int

506− => Expression params tables 'Ungrouped ('Required (nullity int))

507− -> Expression params tables ('Grouped bys) ('Required (nullity int))

508−bitOr = unsafeAggregate "bit_or"

509−

510−boolAnd

511− :: Expression params tables 'Ungrouped ('Required (nullity 'PGbool))

512− -> Expression params tables ('Grouped bys) ('Required (nullity 'PGbool))

513−boolAnd = unsafeAggregate "bool_and"

514−

515−boolOr

516− :: Expression params tables 'Ungrouped ('Required (nullity 'PGbool))

517− -> Expression params tables ('Grouped bys) ('Required (nullity 'PGbool))

518−boolOr = unsafeAggregate "bool_or"

519−

520−countStar

521− :: Expression params table ('Grouped bys) ('Required ('NotNull 'PGint8))

522−countStar = UnsafeExpression "count(*)"

523−

524−count

525− :: Expression params tables 'Ungrouped ('Required ty)

526− -> Expression params tables ('Grouped bys) ('Required ('NotNull 'PGint8))

527−count = unsafeAggregate "count"

528−

529−every

530− :: Expression params tables 'Ungrouped ('Required (nullity 'PGbool))

531− -> Expression params tables ('Grouped bys) ('Required (nullity 'PGbool))

532−every = unsafeAggregate "every"

533−

534−jsonAgg

535− :: Expression params tables 'Ungrouped ('Required ty)

536− -> Expression params tables ('Grouped bys) ('Required ('NotNull 'PGjson))

537−jsonAgg = unsafeAggregate "json_agg"

538−

539−jsonbAgg

540− :: Expression params tables 'Ungrouped ('Required ty)

541− -> Expression params tables ('Grouped bys) ('Required ('NotNull 'PGjsonb))

542−jsonbAgg = unsafeAggregate "jsonb_agg"

543−

544−jsonObjectAgg

545− :: Expression params tables 'Ungrouped ('Required ('NotNull keyty))

546− -> Expression params tables 'Ungrouped ('Required valty)

547− -> Expression params tables ('Grouped bys) ('Required ('NotNull 'PGjson))

548−jsonObjectAgg k v = UnsafeExpression $

549− "json_object_agg(" <> renderExpression k

550− <> ", " <> renderExpression v <> ")"

551−

552−jsonbObjectAgg

553− :: Expression params tables 'Ungrouped ('Required ('NotNull keyty))

554− -> Expression params tables 'Ungrouped ('Required valty)

555− -> Expression params tables ('Grouped bys) ('Required ('NotNull 'PGjsonb))

556−jsonbObjectAgg k v = UnsafeExpression $

557− "jsonb_object_agg(" <> renderExpression k

558− <> ", " <> renderExpression v <> ")"

559−

560−max_

561− :: Expression params tables 'Ungrouped ('Required (nullity ty))

562− -> Expression params tables ('Grouped bys) ('Required (nullity ty))

563−max_ = unsafeAggregate "max"

564−

565−min_

566− :: Expression params tables 'Ungrouped ('Required (nullity ty))

567− -> Expression params tables ('Grouped bys) ('Required (nullity ty))

568−min_ = unsafeAggregate "min"

569−

570−{-----------------------------------------

571−tables

572−-----------------------------------------}

573−

574−newtype Table

575− (schema :: [(Symbol,[(Symbol,ColumnType)])])

576− (columns :: [(Symbol,ColumnType)])

577− = UnsafeTable { renderTable :: ByteString }

578− deriving (Show,Eq)

579−

580−class KnownSymbol table => HasTable table tables columns

581− | table tables -> columns where

582− getTable :: Proxy# table -> Table tables columns

583− getTable table = UnsafeTable $ renderSymbol table

584−instance {-# OVERLAPPING #-} KnownSymbol table

585− => HasTable table ((table ::: columns) ': tables) columns

586−instance {-# OVERLAPPABLE #-}

587− (KnownSymbol table, HasTable table schema columns)

588− => HasTable table (table' ': schema) columns

589−

590−instance HasTable table schema columns

591− => IsLabel table (Table schema columns) where

592− fromLabel = getTable (proxy# @Symbol @table)

593−

594−data TableReference params schema tables where

595− Table

596− :: Aliased (Table schema) table

597− -> TableReference params schema '[table]

598− Subquery

599− :: Aliased (Query schema params) table

600− -> TableReference params schema '[table]

601− CrossJoin

602− :: TableReference params schema right

603− -> TableReference params schema left

604− -> TableReference params schema (Join left right)

605− InnerJoin

606− :: TableReference params schema right

607− -> Condition params (Join left right) 'Ungrouped

608− -> TableReference params schema left

609− -> TableReference params schema (Join left right)

610− LeftOuterJoin

611− :: TableReference params schema right

612− -> Condition params (Join left right) 'Ungrouped

613− -> TableReference params schema left

614− -> TableReference params schema (Join left (NullifyTables right))

615− RightOuterJoin

616− :: TableReference params schema right

617− -> Condition params (Join left right) 'Ungrouped

618− -> TableReference params schema left

619− -> TableReference params schema (Join (NullifyTables left) right)

620− FullOuterJoin

621− :: TableReference params schema right

622− -> Condition params (Join left right) 'Ungrouped

623− -> TableReference params schema left

624− -> TableReference params schema

625− (Join (NullifyTables left) (NullifyTables right))

626−

627−renderTableReference :: TableReference params schema tables -> ByteString

628−renderTableReference = \case

629− Table table -> renderAliased renderTable table

630− Subquery selection -> renderAliased renderQuery selection

631− CrossJoin right left ->

632− renderTableReference left <+> "CROSS JOIN" <+> renderTableReference right

633− InnerJoin right on left -> renderJoin "INNER JOIN" right on left

634− LeftOuterJoin right on left -> renderJoin "LEFT OUTER JOIN" right on left

635− RightOuterJoin right on left -> renderJoin "RIGHT OUTER JOIN" right on left

636− FullOuterJoin right on left -> renderJoin "FULL OUTER JOIN" right on left

637− where

638− renderJoin op right on left =

639− renderTableReference left <+> op <+> renderTableReference right

640− <+> "ON" <+> renderExpression on

641−

642−data TableExpression

643− (params :: [ColumnType])

644− (schema :: [(Symbol,[(Symbol,ColumnType)])])

645− (tables :: [(Symbol,[(Symbol,ColumnType)])])

646− (grouping :: Grouping)

647− = TableExpression

648− { fromClause :: TableReference params schema tables

649− , whereClause :: [Condition params tables 'Ungrouped]

650− , groupByClause :: GroupByClause tables grouping

651− , havingClause :: HavingClause params tables grouping

652− , orderByClause :: [SortExpression params tables grouping]

653− , limitClause :: [Word64]

654− , offsetClause :: [Word64]

655− }

656−

657−renderTableExpression

658− :: TableExpression params schema tables grouping

659− -> ByteString

660−renderTableExpression

661− (TableExpression tables whs' grps' hvs' srts' lims' offs') = mconcat

662− [ "FROM ", renderTableReference tables

663− , renderWheres whs'

664− , renderGroupByClause grps'

665− , renderHavingClause hvs'

666− , renderSorts srts'

667− , renderLimits lims'

668− , renderOffsets offs'

669− ]

670− where

671− renderWheres = \case

672− [] -> ""

673− wh:[] -> " WHERE" <+> renderExpression wh

674− wh:whs -> " WHERE" <+> renderExpression (foldr (&&*) wh whs)

675− renderSorts = \case

676− [] -> ""

677− srts -> " SORT BY"

678− <+> commaSeparated (renderSortExpression <$> srts)

679− renderLimits = \case

680− [] -> ""

681− lims -> " LIMIT" <+> fromString (show (minimum lims))

682− renderOffsets = \case

683− [] -> ""

684− offs -> " OFFSET" <+> fromString (show (sum offs))

685−

686−from

687− :: TableReference params schema tables

688− -> TableExpression params schema tables 'Ungrouped

689−from tables = TableExpression tables [] NoGroups NoHaving [] [] []

690−

691−where_

692− :: Condition params tables 'Ungrouped

693− -> TableExpression params schema tables grouping

694− -> TableExpression params schema tables grouping

695−where_ wh tables = tables {whereClause = wh : whereClause tables}

696−

697−group

698− :: SListI bys

699− => NP (By tables) bys

700− -> TableExpression params schema tables 'Ungrouped

701− -> TableExpression params schema tables ('Grouped bys)

702−group bys tables = TableExpression

703− { fromClause = fromClause tables

704− , whereClause = whereClause tables

705− , groupByClause = Group bys

706− , havingClause = Having []

707− , orderByClause = []

708− , limitClause = limitClause tables

709− , offsetClause = offsetClause tables

710− }

711−

712−having

713− :: Condition params tables ('Grouped bys)

714− -> TableExpression params schema tables ('Grouped bys)

715− -> TableExpression params schema tables ('Grouped bys)

716−having hv tables = tables

717− { havingClause = case havingClause tables of Having hvs -> Having (hv:hvs) }

718−

719−orderBy

720− :: [SortExpression params tables grouping]

721− -> TableExpression params schema tables grouping

722− -> TableExpression params schema tables grouping

723−orderBy srts tables = tables {orderByClause = orderByClause tables ++ srts}

724−

725−limit

726− :: Word64

727− -> TableExpression params schema tables grouping

728− -> TableExpression params schema tables grouping

729−limit lim tables = tables {limitClause = lim : limitClause tables}

730−

731−offset

732− :: Word64

733− -> TableExpression params schema tables grouping

734− -> TableExpression params schema tables grouping

735−offset off tables = tables {offsetClause = off : offsetClause tables}

736−

737−{-----------------------------------------

738−type expressions

739−-----------------------------------------}

740−

741−newtype TypeExpression (ty :: ColumnType)

742− = UnsafeTypeExpression { renderTypeExpression :: ByteString }

743− deriving (Show,Eq)

744−

745−bool :: TypeExpression ('Required ('Null 'PGbool))

746−bool = UnsafeTypeExpression "bool"

747−int2 :: TypeExpression ('Required ('Null 'PGint2))

748−int2 = UnsafeTypeExpression "int2"

749−smallint :: TypeExpression ('Required ('Null 'PGint2))

750−smallint = UnsafeTypeExpression "smallint"

751−int4 :: TypeExpression ('Required ('Null 'PGint4))

752−int4 = UnsafeTypeExpression "int4"

753−int :: TypeExpression ('Required ('Null 'PGint4))

754−int = UnsafeTypeExpression "int"

755−integer :: TypeExpression ('Required ('Null 'PGint4))

756−integer = UnsafeTypeExpression "integer"

757−int8 :: TypeExpression ('Required ('Null 'PGint8))

758−int8 = UnsafeTypeExpression "int8"

759−bigint :: TypeExpression ('Required ('Null 'PGint8))

760−bigint = UnsafeTypeExpression "bigint"

761−numeric :: TypeExpression ('Required ('Null 'PGnumeric))

762−numeric = UnsafeTypeExpression "numeric"

763−float4 :: TypeExpression ('Required ('Null 'PGfloat4))

764−float4 = UnsafeTypeExpression "float4"

765−real :: TypeExpression ('Required ('Null 'PGfloat4))

766−real = UnsafeTypeExpression "real"

767−float8 :: TypeExpression ('Required ('Null 'PGfloat8))

768−float8 = UnsafeTypeExpression "float8"

769−doublePrecision :: TypeExpression ('Required ('Null 'PGfloat8))

770−doublePrecision = UnsafeTypeExpression "double precision"

771−serial2 :: TypeExpression ('Optional ('NotNull 'PGint2))

772−serial2 = UnsafeTypeExpression "serial2"

773−smallserial :: TypeExpression ('Optional ('NotNull 'PGint2))

774−smallserial = UnsafeTypeExpression "smallserial"

775−serial4 :: TypeExpression ('Optional ('NotNull 'PGint4))

776−serial4 = UnsafeTypeExpression "serial4"

777−serial :: TypeExpression ('Optional ('NotNull 'PGint4))

778−serial = UnsafeTypeExpression "serial"

779−serial8 :: TypeExpression ('Optional ('NotNull 'PGint8))

780−serial8 = UnsafeTypeExpression "serial8"

781−bigserial :: TypeExpression ('Optional ('NotNull 'PGint8))

782−bigserial = UnsafeTypeExpression "bigserial"

783−text :: TypeExpression ('Required ('Null 'PGtext))

784−text = UnsafeTypeExpression "text"

785−char

786− :: KnownNat n

787− => proxy n

788− -> TypeExpression ('Required ('Null ('PGchar n)))

789−char p = UnsafeTypeExpression $ "char(" <> renderNat p <> ")"

790−character

791− :: KnownNat n

792− => proxy n

793− -> TypeExpression ('Required ('Null ('PGchar n)))

794−character p = UnsafeTypeExpression $ "character(" <> renderNat p <> ")"

795−varchar

796− :: KnownNat n

797− => proxy n

798− -> TypeExpression ('Required ('Null ('PGvarchar n)))

799−varchar p = UnsafeTypeExpression $ "varchar(" <> renderNat p <> ")"

800−characterVarying

801− :: KnownNat n

802− => proxy n

803− -> TypeExpression ('Required ('Null ('PGvarchar n)))

804−characterVarying p = UnsafeTypeExpression $

805− "character varying(" <> renderNat p <> ")"

806−bytea :: TypeExpression ('Required ('Null ('PGbytea)))

807−bytea = UnsafeTypeExpression "bytea"

808−timestamp :: TypeExpression ('Required ('Null ('PGtimestamp)))

809−timestamp = UnsafeTypeExpression "timestamp"

810−timestampWithTimeZone :: TypeExpression ('Required ('Null ('PGtimestamptz)))

811−timestampWithTimeZone = UnsafeTypeExpression "timestamp with time zone"

812−date :: TypeExpression ('Required ('Null ('PGdate)))

813−date = UnsafeTypeExpression "date"

814−time :: TypeExpression ('Required ('Null ('PGtime)))

815−time = UnsafeTypeExpression "time"

816−timeWithTimeZone :: TypeExpression ('Required ('Null ('PGtimetz)))

817−timeWithTimeZone = UnsafeTypeExpression "time with time zone"

818−interval :: TypeExpression ('Required ('Null ('PGinterval)))

819−interval = UnsafeTypeExpression "interval"

820−uuid :: TypeExpression ('Required ('Null ('PGuuid)))

821−uuid = UnsafeTypeExpression "uuid"

822−json :: TypeExpression ('Required ('Null ('PGjson)))

823−json = UnsafeTypeExpression "json"

824−jsonb :: TypeExpression ('Required ('Null ('PGjsonb)))

825−jsonb = UnsafeTypeExpression "jsonb"

826−

827−notNull

828− :: TypeExpression (optionality ('Null ty))

829− -> TypeExpression (optionality ('NotNull ty))

830−notNull ty = UnsafeTypeExpression $ renderTypeExpression ty <+> "NOT NULL"

831−default_

832− :: Expression '[] '[] 'Ungrouped ('Required ty)

833− -> TypeExpression ('Required ty)

834− -> TypeExpression ('Optional ty)

835−default_ x ty = UnsafeTypeExpression $

836− renderTypeExpression ty <+> "DEFAULT" <+> renderExpression x

837−

838−class PGTyped (ty :: PGType) where

839− pgtype :: TypeExpression ('Required ('Null ty))

840−instance PGTyped 'PGbool where pgtype = bool

841−instance PGTyped 'PGint2 where pgtype = int2

842−instance PGTyped 'PGint4 where pgtype = int4

843−instance PGTyped 'PGint8 where pgtype = int8

844−instance PGTyped 'PGnumeric where pgtype = numeric

845−instance PGTyped 'PGfloat4 where pgtype = float4

846−instance PGTyped 'PGfloat8 where pgtype = float8

847−instance PGTyped 'PGtext where pgtype = text

848−instance KnownNat n => PGTyped ('PGchar n) where pgtype = char (Proxy @n)

849−instance KnownNat n => PGTyped ('PGvarchar n) where pgtype = varchar (Proxy @n)

850−instance PGTyped 'PGbytea where pgtype = bytea

851−instance PGTyped 'PGtimestamp where pgtype = timestamp

852−instance PGTyped 'PGtimestamptz where pgtype = timestampWithTimeZone

853−instance PGTyped 'PGdate where pgtype = date

854−instance PGTyped 'PGtime where pgtype = time

855−instance PGTyped 'PGtimetz where pgtype = timeWithTimeZone

856−instance PGTyped 'PGinterval where pgtype = interval

857−instance PGTyped 'PGuuid where pgtype = uuid

858−instance PGTyped 'PGjson where pgtype = json

859−instance PGTyped 'PGjsonb where pgtype = jsonb

860−

861−{-----------------------------------------

862−statements

863−-----------------------------------------}

864−

865−newtype Definition

866− (schema0 :: [(Symbol,[(Symbol,ColumnType)])])

867− (schema1 :: [(Symbol,[(Symbol,ColumnType)])])

868− = UnsafeDefinition { renderDefinition :: ByteString }

869−

870−instance Category Definition where

871− id = UnsafeDefinition ";"

872− ddl1 . ddl0 = UnsafeDefinition $

873− renderDefinition ddl0 <+> renderDefinition ddl1

874−

875−newtype Manipulation

876− (schema :: [(Symbol,[(Symbol,ColumnType)])])

877− (params :: [ColumnType])

878− (columns :: [(Symbol,ColumnType)])

879− = UnsafeManipulation { renderManipulation :: ByteString }

880−

881−newtype Query

882− (schema :: [(Symbol,[(Symbol,ColumnType)])])

883− (params :: [ColumnType])

884− (columns :: [(Symbol,ColumnType)])

885− = UnsafeQuery { renderQuery :: ByteString }

886−

887−query

888− :: Query schema params columns

889− -> Manipulation schema params columns

890−query q = UnsafeManipulation $ renderQuery q <> ";"

891−

892−union, unionAll, intersect, intersectAll, except, exceptAll

893− :: Query schema params columns

894− -> Query schema params columns

895− -> Query schema params columns

896−q1 `union` q2 = UnsafeQuery $

897− parenthesized (renderQuery q1)

898− <+> "UNION"

899− <+> parenthesized (renderQuery q2)

900−q1 `unionAll` q2 = UnsafeQuery $

901− parenthesized (renderQuery q1)

902− <+> "UNION" <+> "ALL"

903− <+> parenthesized (renderQuery q2)

904−q1 `intersect` q2 = UnsafeQuery $

905− parenthesized (renderQuery q1)

906− <+> "INTERSECT"

907− <+> parenthesized (renderQuery q2)

908−q1 `intersectAll` q2 = UnsafeQuery $

909− parenthesized (renderQuery q1)

910− <+> "INTERSECT" <+> "ALL"

911− <+> parenthesized (renderQuery q2)

912−q1 `except` q2 = UnsafeQuery $

913− parenthesized (renderQuery q1)

914− <+> "EXCEPT"

915− <+> parenthesized (renderQuery q2)

916−q1 `exceptAll` q2 = UnsafeQuery $

917− parenthesized (renderQuery q1)

918− <+> "EXCEPT" <+> "ALL"

919− <+> parenthesized (renderQuery q2)

920−

921−{-----------------------------------------

922−SELECT statements

923−-----------------------------------------}

924−

925−select

926− :: SListI columns

927− => NP (Aliased (Expression params tables grouping)) (column ': columns)

928− -> TableExpression params schema tables grouping

929− -> Query schema params (column ': columns)

930−select list tabs = UnsafeQuery $

931− "SELECT"

932− <+> renderCommaSeparated (renderAliased renderExpression) list

933− <+> renderTableExpression tabs

934−

935−selectStar

936− :: (tables ~ '[table ::: columns])

937− => TableExpression params schema tables 'Ungrouped

938− -> Query schema params columns

939−selectStar tabs = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression tabs

940−

941−selectDotStar

942− :: HasTable table tables columns

943− => Alias table

944− -> TableExpression params schema tables 'Ungrouped

945− -> Query schema params columns

946−selectDotStar table tables = UnsafeQuery $

947− "SELECT" <+> renderAlias table <> ".*" <+> renderTableExpression tables

948−

949−selectRow

950− :: SListI columns

951− => NP (Aliased (Expression params '[] 'Ungrouped)) columns

952− -> Query schema params columns

953−selectRow row = UnsafeQuery $

954− "SELECT" <+> renderCommaSeparated (renderAliased renderExpression) row

955−

956−{-----------------------------------------

957−CREATE statements

958−-----------------------------------------}

959−

960−createTable

961− :: (KnownSymbol table, SListI columns)

962− => Alias table

963− -> NP (Aliased TypeExpression) (column ': columns)

964− -> [TableConstraint schema (column ': columns)]

965− -> Definition schema (Create table (column ': columns) schema)

966−createTable table columns constraints = UnsafeDefinition $

967− "CREATE TABLE" <+> renderAlias table

968− <+> parenthesized

969− ( renderCommaSeparated renderColumnDef columns

970− <> renderConstraints constraints )

971− <> ";"

972− where

973− renderColumnDef :: Aliased TypeExpression x -> ByteString

974− renderColumnDef (ty `As` column) =

975− renderAlias column <+> renderTypeExpression ty

976− renderConstraints :: [TableConstraint schema columns] -> ByteString

977− renderConstraints = \case

978− [] -> ""

979− _ -> ", " <> commaSeparated (renderTableConstraint <$> constraints)

980−

981−data TableConstraint

982− (schema :: [(Symbol,[(Symbol,ColumnType)])])

983− (columns :: [(Symbol,ColumnType)])

984− = UnsafeTableConstraint { renderTableConstraint :: ByteString }

985−

986−check

987− :: Condition '[] '[table ::: columns] 'Ungrouped

988− -> TableConstraint schema columns

989−check condition = UnsafeTableConstraint $

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

991−

992−data Column

993− (columns :: [(Symbol,ColumnType)])

994− (columnty :: (Symbol,ColumnType))

995− where

996− Column

997− :: HasColumn column columns ty

998− => Alias column

999− -> Column columns (column ::: ty)

1000−

1001−renderColumn :: Column columns columnty -> ByteString

1002−renderColumn (Column column) = renderAlias column

1003−

1004−unique

1005− :: SListI subcolumns

1006− => NP (Column columns) subcolumns

1007− -> TableConstraint schema columns

1008−unique columns = UnsafeTableConstraint $

1009− "UNIQUE" <+> parenthesized (renderCommaSeparated renderColumn columns)

1010−

1011−primaryKey

1012− :: (SListI subcolumns, NotNullTypes subcolumns)

1013− => NP (Column columns) subcolumns

1014− -> TableConstraint schema columns

1015−primaryKey columns = UnsafeTableConstraint $

1016− "PRIMARY KEY" <+> parenthesized (renderCommaSeparated renderColumn columns)

1017−

1018−type family SameTypes columns0 columns1 :: Constraint where

1019− SameTypes '[] '[] = ()

1020− SameTypes ((column0 ::: ty0) ': columns0) ((column1 ::: ty1) ': columns1)

1021− = (ty0 ~ ty1, SameTypes columns0 columns1)

1022−

1023−type family NotNullTypes columns :: Constraint where

1024− NotNullTypes '[] = ()

1025− NotNullTypes ((column ::: (optionality ('NotNull ty))) ': columns)

1026− = NotNullTypes columns

1027−

1028−foreignKey

1029− :: ( HasTable reftable schema refcolumns

1030− , SameTypes subcolumns refsubcolumns

1031− , NotNullTypes subcolumns

1032− , SListI subcolumns

1033− , SListI refsubcolumns)

1034− => NP (Column columns) subcolumns

1035− -> Alias reftable

1036− -> NP (Column refcolumns) refsubcolumns

1037− -> TableConstraint schema columns

1038−foreignKey columns reftable refcolumns = UnsafeTableConstraint $

1039− "FOREIGN KEY" <+> parenthesized (renderCommaSeparated renderColumn columns)

1040− <+> "REFERENCES" <+> renderAlias reftable

1041− <+> parenthesized (renderCommaSeparated renderColumn refcolumns)

1042−

1043−{-----------------------------------------

1044−DROP statements

1045−-----------------------------------------}

1046−

1047−dropTable

1048− :: KnownSymbol table

1049− => Alias table

1050− -> Definition schema (Drop table schema)

1051−dropTable table = UnsafeDefinition $ "DROP TABLE" <+> renderAlias table <> ";"

1052−

1053−{-----------------------------------------

1054−ALTER statements

1055−-----------------------------------------}

1056−

1057−alterTable

1058− :: HasTable table schema columns0

1059− => Alias table

1060− -> AlterTable columns0 columns1

1061− -> Definition schema (Alter table schema columns1)

1062−alterTable table alteration = UnsafeDefinition $

1063− "ALTER TABLE"

1064− <+> renderAlias table

1065− <+> renderAlterTable alteration

1066− <> ";"

1067−

1068−alterTableRename

1069− :: (KnownSymbol table0, KnownSymbol table1)

1070− => Alias table0

1071− -> Alias table1

1072− -> Definition schema (Rename table0 table1 schema)

1073−alterTableRename table0 table1 = UnsafeDefinition $

1074− "ALTER TABLE" <+> renderAlias table0

1075− <+> "RENAME TO" <+> renderAlias table1 <> ";"

1076−

1077−data AlterTable

1078− (columns0 :: [(Symbol, ColumnType)])

1079− (columns1 :: [(Symbol, ColumnType)]) =

1080− UnsafeAlterTable {renderAlterTable :: ByteString}

1081−

1082−addColumnDefault

1083− :: KnownSymbol column

1084− => Alias column

1085− -> TypeExpression ('Optional ty)

1086− -> AlterTable columns (Create column ('Optional ty) columns)

1087−addColumnDefault column ty = UnsafeAlterTable $

1088− "ADD COLUMN" <+> renderAlias column <+> renderTypeExpression ty

1089−

1090−addColumnNull

1091− :: KnownSymbol column

1092− => Alias column

1093− -> TypeExpression ('Required ('Null ty))

1094− -> AlterTable columns ((column ::: 'Required ('Null ty)) ': columns)

1095−addColumnNull column ty = UnsafeAlterTable $

1096− "ADD COLUMN" <+> renderAlias column <+> renderTypeExpression ty

1097−

1098−dropColumn

1099− :: KnownSymbol column

1100− => Alias column

1101− -> AlterTable columns (Drop column columns)

1102−dropColumn column = UnsafeAlterTable $

1103− "DROP COLUMN" <+> renderAlias column

1104−

1105−renameColumn

1106− :: (KnownSymbol column0, KnownSymbol column1)

1107− => Alias column0

1108− -> Alias column1

1109− -> AlterTable columns (Rename column0 column1 columns)

1110−renameColumn column0 column1 = UnsafeAlterTable $

1111− "RENAME COLUMN" <+> renderAlias column0 <+> "TO" <+> renderAlias column1

1112−

1113−alterColumn

1114− :: (KnownSymbol column, HasColumn column columns ty0)

1115− => Alias column

1116− -> AlterColumn ty0 ty1

1117− -> AlterTable columns (Alter column columns ty1)

1118−alterColumn column alteration = UnsafeAlterTable $

1119− "ALTER COLUMN" <+> renderAlias column <+> renderAlterColumn alteration

1120−

1121−data AlterColumn (ty0 :: ColumnType) (ty1 :: ColumnType) =

1122− UnsafeAlterColumn {renderAlterColumn :: ByteString}

1123−

1124−setDefault

1125− :: Expression '[] '[] 'Ungrouped ('Required ty)

1126− -> AlterColumn ('Required ty) ('Optional ty)

1127−setDefault expression = UnsafeAlterColumn $

1128− "SET DEFAULT" <+> renderExpression expression

1129−

1130−dropDefault :: AlterColumn ('Optional ty) ('Required ty)

1131−dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"

1132−

1133−setNotNull

1134− :: AlterColumn (optionality ('Null ty)) (optionality ('NotNull ty))

1135−setNotNull = UnsafeAlterColumn $ "SET NOT NULL"

1136−

1137−dropNotNull

1138− :: AlterColumn (optionality ('NotNull ty)) (optionality ('Null ty))

1139−dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"

1140−

1141−alterType

1142− :: TypeExpression (optionality (nullity ty1))

1143− -> AlterColumn (optionality (nullity ty0)) (optionality (nullity ty1))

1144−alterType ty = UnsafeAlterColumn $ "TYPE " <> renderTypeExpression ty

1145−

1146−{-----------------------------------------

1147−INSERT statements

1148−-----------------------------------------}

1149−

1150−insertInto

1151− :: (SListI columns, SListI results, HasTable table schema columns)

1152− => Alias table

1153− -> ValuesClause schema params columns

1154− -> ConflictClause params columns

1155− -> ReturningClause params columns results

1156− -> Manipulation schema params results

1157−insertInto table insert conflict returning = UnsafeManipulation $

1158− "INSERT" <+> "INTO" <+> renderAlias table

1159− <+> renderValuesClause insert

1160− <> renderConflictClause conflict

1161− <> renderReturningClause returning

1162−

1163−data ValuesClause

1164− (schema :: [(Symbol,[(Symbol,ColumnType)])])

1165− (params :: [ColumnType])

1166− (columns :: [(Symbol,ColumnType)])

1167− = Values

1168− (NP (Aliased (Expression params '[] 'Ungrouped)) columns)

1169− [NP (Aliased (Expression params '[] 'Ungrouped)) columns]

1170− | ValuesQuery (Query schema params columns)

1171−

1172−renderValuesClause

1173− :: SListI columns

1174− => ValuesClause schema params columns

1175− -> ByteString

1176−renderValuesClause = \case

1177− Values row rows ->

1178− parenthesized (renderCommaSeparated renderAliasPart row)

1179− <+> "VALUES"

1180− <+> commaSeparated

1181− (parenthesized . renderCommaSeparated renderValuePart <$> row:rows)

1182− where

1183− renderAliasPart, renderValuePart

1184− :: Aliased (Expression params '[] 'Ungrouped) ty -> ByteString

1185− renderAliasPart (_ `As` name) = renderAlias name

1186− renderValuePart (value `As` _) = renderExpression value

1187− ValuesQuery q -> renderQuery q

1188−

1189−data ReturningClause

1190− (params :: [ColumnType])

1191− (columns :: [(Symbol,ColumnType)])

1192− (results :: [(Symbol,ColumnType)])

1193− where

1194− ReturningStar :: ReturningClause params columns columns

1195− Returning

1196− :: NP (Aliased (Expression params '[table ::: columns] 'Ungrouped))

1197− results

1198− -> ReturningClause params columns results

1199−

1200−renderReturningClause

1201− :: SListI results

1202− => ReturningClause params columns results

1203− -> ByteString

1204−renderReturningClause = \case

1205− ReturningStar -> " RETURNING *;"

1206− Returning Nil -> ";"

1207− Returning results -> " RETURNING"

1208− <+> renderCommaSeparated (renderAliased renderExpression) results <> ";"

1209−

1210−data ConflictClause params columns where

1211− Conflict :: ConflictClause params columns

1212− OnConflictDoNothing :: ConflictClause params columns

1213− OnConflictDoUpdate

1214− :: NP (Aliased (UpdateExpression params '[table ::: columns])) columns

1215− -> Condition params '[table ::: columns] 'Ungrouped

1216− -> ConflictClause params columns

1217−

1218−renderConflictClause

1219− :: SListI columns

1220− => ConflictClause params columns

1221− -> ByteString

1222−renderConflictClause = \case

1223− Conflict -> ""

1224− OnConflictDoNothing -> " ON CONFLICT DO NOTHING"

1225− OnConflictDoUpdate updates wh

1226− -> " ON CONFLICT DO UPDATE SET"

1227− <+> renderCommaSeparatedMaybe renderUpdateExpression updates

1228− <+> "WHERE" <+> renderExpression wh

1229−

1230−{-----------------------------------------

1231−UPDATE statements

1232−-----------------------------------------}

1233−

1234−data UpdateExpression params table ty

1235− = Same

1236− | Set (Expression params table 'Ungrouped ty)

1237−

1238−renderUpdateExpression

1239− :: Aliased (UpdateExpression params '[table ::: columns]) column

1240− -> Maybe ByteString

1241−renderUpdateExpression = \case

1242− Same `As` _ -> Nothing

1243− Set expression `As` column -> Just $

1244− renderAlias column <+> "=" <+> renderExpression expression

1245−

1246−update

1247− :: (HasTable table schema columns, SListI columns, SListI results)

1248− => Alias table

1249− -> NP (Aliased (UpdateExpression params '[table ::: columns])) columns

1250− -> Condition params '[table ::: columns] 'Ungrouped

1251− -> ReturningClause params columns results

1252− -> Manipulation schema params results

1253−update table columns wh returning = UnsafeManipulation $

1254− "UPDATE"

1255− <+> renderAlias table

1256− <+> "SET"

1257− <+> renderCommaSeparatedMaybe renderUpdateExpression columns

1258− <+> "WHERE" <+> renderExpression wh

1259− <> renderReturningClause returning

1260−

1261−{-----------------------------------------

1262−DELETE statements

1263−-----------------------------------------}

1264−

1265−deleteFrom

1266− :: HasTable table schema columns

1267− => Alias table

1268− -> Condition params '[table ::: columns] 'Ungrouped

1269− -> Manipulation schema params '[]

1270−deleteFrom table wh = UnsafeManipulation $

1271− "DELETE FROM" <+> renderAlias table

1272− <+> "WHERE" <+> renderExpression wh <> ";"

1273−

1274−{-----------------------------------------

1275−render helper functions

1276−-----------------------------------------}

1277−

1278−parenthesized :: ByteString -> ByteString

1279−parenthesized str = "(" <> str <> ")"

1280−

1281−(<+>) :: ByteString -> ByteString -> ByteString

1282−str1 <+> str2 = str1 <> " " <> str2

1283−

1284−commaSeparated :: [ByteString] -> ByteString

1285−commaSeparated = ByteString.intercalate ", "

1286−

1287−renderCommaSeparated

1288− :: SListI xs

1289− => (forall x. expression x -> ByteString)

1290− -> NP expression xs -> ByteString

1291−renderCommaSeparated render

1292− = commaSeparated

1293− . hcollapse

1294− . hmap (K . render)

1295−

1296−renderCommaSeparatedMaybe

1297− :: SListI xs

1298− => (forall x. expression x -> Maybe ByteString)

1299− -> NP expression xs -> ByteString

1300−renderCommaSeparatedMaybe render

1301− = commaSeparated

1302− . catMaybes

1303− . hcollapse

1304− . hmap (K . render)

1305−

1306−renderSymbol :: KnownSymbol str => Proxy# str -> ByteString

1307−renderSymbol p = fromString $ symbolVal' p

1308−

1309−renderNat :: KnownNat n => proxy n -> ByteString

1310−renderNat (_ :: proxy n) = fromString (show (natVal' (proxy# :: Proxy# n)))

squeal-postgresql/src/Squeal/PostgreSQL/Transaction.hsnew file+252

@@ -0,0 +1,252 @@

1+{-|

2+Module: Squeal.PostgreSQL.Transaction

3+Description: Squeal transaction control language

4+Copyright: (c) Eitan Chatav, 2019

5+Maintainer: eitan@morphism.tech

6+Stability: experimental

8+Squeal transaction control language.

9+-}

10+

11+{-# LANGUAGE

12+ DataKinds

13+ , FlexibleContexts

14+ , LambdaCase

15+ , OverloadedStrings

16+ , TypeInType

17+#-}

18+

19+module Squeal.PostgreSQL.Transaction

20+ ( -- * Transaction

21+ transactionally

22+ , transactionally_

23+ , transactionallyRetry

24+ , ephemerally

25+ , ephemerally_

26+ , begin

27+ , commit

28+ , rollback

29+ -- * Transaction Mode

30+ , TransactionMode (..)

31+ , defaultMode

32+ , longRunningMode

33+ , IsolationLevel (..)

34+ , AccessMode (..)

35+ , DeferrableMode (..)

36+ ) where

37+

38+import UnliftIO

39+

40+import Squeal.PostgreSQL.Manipulation

41+import Squeal.PostgreSQL.Render

42+import Squeal.PostgreSQL.PQ

43+

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+-}

50+transactionally

51+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

52+ => TransactionMode

53+ -> tx x -- ^ run inside a transaction

54+ -> tx x

55+transactionally mode tx = mask $ \restore -> do

56+ manipulate_ $ begin mode

57+ result <- restore tx `onException` (manipulate_ rollback)

58+ manipulate_ commit

59+ return result

60+

61+-- | Run a computation `transactionally_`, in `defaultMode`.

62+transactionally_

63+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

64+ => tx x -- ^ run inside a transaction

65+ -> tx x

66+transactionally_ = transactionally defaultMode

67+

68+{- |

69+`transactionallyRetry` a computation;

70+

71+* first `begin`,

72+* then `try` the computation,

73+ - if it raises a serialization failure then `rollback` and restart the transaction,

74+ - if it raises any other exception then `rollback` and rethrow the exception,

75+ - otherwise `commit` and `return` the result.

76+-}

77+transactionallyRetry

78+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

79+ => TransactionMode

80+ -> tx x -- ^ run inside a transaction

81+ -> tx x

82+transactionallyRetry mode tx = mask $ \restore ->

83+ loop . try $ do

84+ x <- restore tx

85+ manipulate_ commit

86+ return x

87+ where

88+ loop attempt = do

89+ manipulate_ $ begin mode

90+ attempt >>= \case

91+ Left (PQException (PQState _ (Just "40001") _)) -> do

92+ manipulate_ rollback

93+ loop attempt

94+ Left err -> do

95+ manipulate_ rollback

96+ throwIO err

97+ Right x -> return x

98+

99+{- | Run a computation `ephemerally`;

100+Like `transactionally` but always `rollback`, useful in testing.

101+-}

102+ephemerally

103+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

104+ => TransactionMode

105+ -> tx x -- ^ run inside an ephemeral transaction

106+ -> tx x

107+ephemerally mode tx = mask $ \restore -> do

108+ manipulate_ $ begin mode

109+ result <- restore tx `onException` (manipulate_ rollback)

110+ manipulate_ rollback

111+ return result

112+

113+{- | Run a computation `ephemerally` in `defaultMode`. -}

114+ephemerally_

115+ :: (MonadUnliftIO tx, MonadPQ schemas tx)

116+ => tx x -- ^ run inside an ephemeral transaction

117+ -> tx x

118+ephemerally_ = ephemerally defaultMode

119+

120+-- | @BEGIN@ a transaction.

121+begin :: TransactionMode -> Manipulation_ schemas () ()

122+begin mode = UnsafeManipulation $ "BEGIN" <+> renderSQL mode

123+

124+-- | @COMMIT@ a transaction.

125+commit :: Manipulation_ schemas () ()

126+commit = UnsafeManipulation "COMMIT"

127+

128+-- | @ROLLBACK@ a transaction.

129+rollback :: Manipulation_ schemas () ()

130+rollback = UnsafeManipulation "ROLLBACK"

131+

132+-- | The available transaction characteristics are the transaction `IsolationLevel`,

133+-- the transaction `AccessMode` (`ReadWrite` or `ReadOnly`), and the `DeferrableMode`.

134+data TransactionMode = TransactionMode

135+ { isolationLevel :: IsolationLevel

136+ , accessMode :: AccessMode

137+ , deferrableMode :: DeferrableMode

138+ } deriving (Show, Eq)

139+

140+-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

141+-- `ReadWrite` `AccessMode` and `NotDeferrable` `DeferrableMode`.

142+defaultMode :: TransactionMode

143+defaultMode = TransactionMode ReadCommitted ReadWrite NotDeferrable

144+

145+-- | `TransactionMode` with a `Serializable` `IsolationLevel`,

146+-- `ReadOnly` `AccessMode` and `Deferrable` `DeferrableMode`.

147+-- This mode is well suited for long-running reports or backups.

148+longRunningMode :: TransactionMode

149+longRunningMode = TransactionMode Serializable ReadOnly Deferrable

150+

151+-- | Render a `TransactionMode`.

152+instance RenderSQL TransactionMode where

153+ renderSQL mode =

154+ "ISOLATION LEVEL"

155+ <+> renderSQL (isolationLevel mode)

156+ <+> renderSQL (accessMode mode)

157+ <+> renderSQL (deferrableMode mode)

158+

159+-- | The SQL standard defines four levels of transaction isolation.

160+-- The most strict is `Serializable`, which is defined by the standard in a paragraph

161+-- which says that any concurrent execution of a set of `Serializable` transactions is

162+-- guaranteed to produce the same effect as running them one at a time in some order.

163+-- The other three levels are defined in terms of phenomena, resulting from interaction

164+-- between concurrent transactions, which must not occur at each level.

165+-- The phenomena which are prohibited at various levels are:

166+--

167+-- __Dirty read__: A transaction reads data written by a concurrent uncommitted transaction.

168+--

169+-- __Nonrepeatable read__: A transaction re-reads data it has previously read and finds that data

170+-- has been modified by another transaction (that committed since the initial read).

171+--

172+-- __Phantom read__: A transaction re-executes a query returning a set of rows that satisfy

173+-- a search condition and finds that the set of rows satisfying the condition

174+-- has changed due to another recently-committed transaction.

175+--

176+-- __Serialization anomaly__: The result of successfully committing a group of transactions is inconsistent

177+-- with all possible orderings of running those transactions one at a time.

178+--

179+-- In PostgreSQL, you can request any of the four standard transaction

180+-- isolation levels, but internally only three distinct isolation levels are implemented,

181+-- i.e. PostgreSQL's `ReadUncommitted` mode behaves like `ReadCommitted`.

182+-- This is because it is the only sensible way to map the standard isolation levels to

183+-- PostgreSQL's multiversion concurrency control architecture.

184+data IsolationLevel

185+ = Serializable

186+ -- ^ Dirty read is not possible.

187+ -- Nonrepeatable read is not possible.

188+ -- Phantom read is not possible.

189+ -- Serialization anomaly is not possible.

190+ | RepeatableRead

191+ -- ^ Dirty read is not possible.

192+ -- Nonrepeatable read is not possible.

193+ -- Phantom read is not possible.

194+ -- Serialization anomaly is possible.

195+ | ReadCommitted

196+ -- ^ Dirty read is not possible.

197+ -- Nonrepeatable read is possible.

198+ -- Phantom read is possible.

199+ -- Serialization anomaly is possible.

200+ | ReadUncommitted

201+ -- ^ Dirty read is not possible.

202+ -- Nonrepeatable read is possible.

203+ -- Phantom read is possible.

204+ -- Serialization anomaly is possible.

205+ deriving (Show, Eq)

206+

207+-- | Render an `IsolationLevel`.

208+instance RenderSQL IsolationLevel where

209+ renderSQL = \case

210+ Serializable -> "SERIALIZABLE"

211+ ReadCommitted -> "READ COMMITTED"

212+ ReadUncommitted -> "READ UNCOMMITTED"

213+ RepeatableRead -> "REPEATABLE READ"

214+

215+-- | The transaction access mode determines whether the transaction is `ReadWrite` or `ReadOnly`.

216+-- `ReadWrite` is the default. When a transaction is `ReadOnly`,

217+-- the following SQL commands are disallowed:

218+-- @INSERT@, @UPDATE@, @DELETE@, and @COPY FROM@

219+-- if the table they would write to is not a temporary table;

220+-- all @CREATE@, @ALTER@, and @DROP@ commands;

221+-- @COMMENT@, @GRANT@, @REVOKE@, @TRUNCATE@;

222+-- and @EXPLAIN ANALYZE@ and @EXECUTE@ if the command they would execute is among those listed.

223+-- This is a high-level notion of `ReadOnly` that does not prevent all writes to disk.

224+data AccessMode

225+ = ReadWrite

226+ | ReadOnly

227+ deriving (Show, Eq)

228+

229+-- | Render an `AccessMode`.

230+instance RenderSQL AccessMode where

231+ renderSQL = \case

232+ ReadWrite -> "READ WRITE"

233+ ReadOnly -> "READ ONLY"

234+

235+-- | The `Deferrable` transaction property has no effect

236+-- unless the transaction is also `Serializable` and `ReadOnly`.

237+-- When all three of these properties are selected for a transaction,

238+-- the transaction may block when first acquiring its snapshot,

239+-- after which it is able to run without the normal overhead of a

240+-- `Serializable` transaction and without any risk of contributing

241+-- to or being canceled by a serialization failure.

242+-- This `longRunningMode` is well suited for long-running reports or backups.

243+data DeferrableMode

244+ = Deferrable

245+ | NotDeferrable

246+ deriving (Show, Eq)

247+

248+-- | Render a `DeferrableMode`.

249+instance RenderSQL DeferrableMode where

250+ renderSQL = \case

251+ Deferrable -> "DEFERRABLE"

252+ NotDeferrable -> "NOT DEFERRABLE"

squeal-postgresql/test/Doc.hsnew file+6

@@ -0,0 +1,6 @@

1+module Main (main) where

3+import Test.DocTest

5+main :: IO ()

6+main = doctest [ "-isrc", "src" ]

squeal-postgresql/test/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.hs+136−1

@@ -1 +1,136 @@

1−{-# OPTIONS_GHC -F -pgmF hspec-discover #-}

1+{-# LANGUAGE

2+ DataKinds

3+ , DeriveAnyClass

4+ , DeriveGeneric

5+ , DerivingStrategies

6+ , DuplicateRecordFields

7+ , FlexibleContexts

8+ , OverloadedLabels

9+ , OverloadedLists

10+ , OverloadedStrings

11+ , TypeApplications

12+ , TypeFamilies

13+ , TypeInType

14+ , TypeOperators

15+#-}

16+

17+module Main (main) where

18+

19+import Control.Concurrent.Async (replicateConcurrently)

20+import Data.ByteString (ByteString)

21+import Data.Int (Int32)

22+import Data.Text (Text)

23+import Test.Hspec

24+

25+import qualified Generics.SOP as SOP

26+import qualified GHC.Generics as GHC

27+

28+import Squeal.PostgreSQL

29+

30+main :: IO ()

31+main = hspec spec

32+

33+type Schemas = Public

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

35+ '[ "pk_users" ::: 'PrimaryKey '["id"]

36+ , "unique_names" ::: 'Unique '["name"]

37+ ] :=>

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

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

40+

41+data User = User

42+ { userName :: Text

43+ } deriving stock (Eq, Show, GHC.Generic)

44+ deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)

45+

46+insertUser :: Manipulation_ Schemas User ()

47+insertUser = insertInto_ #users

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

49+

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

51+setup =

52+ createTable #users

53+ ( serial `as` #id :*

54+ notNullable text `as` #name )

55+ ( primaryKey #id `as` #pk_users :*

56+ unique #name `as` #unique_names )

57+

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

59+teardown = dropTable #users

60+

61+silence :: MonadPQ schemas pq => pq ()

62+silence = manipulate_ $

63+ UnsafeManipulation "SET client_min_messages TO WARNING;"

64+

65+setupDB :: IO ()

66+setupDB = withConnection connectionString $

67+ silence & pqThen (define setup)

68+

69+dropDB :: IO ()

70+dropDB = withConnection connectionString $

71+ silence & pqThen (define teardown)

72+

73+connectionString :: ByteString

74+connectionString = "host=localhost port=5432 dbname=exampledb"

75+

76+spec :: Spec

77+spec = before_ setupDB . after_ dropDB $ do

78+

79+ describe "Exceptions" $ do

80+

81+ let

82+ testUser = User "TestUser"

83+ newUser = manipulateParams_ insertUser

84+ insertUserTwice = newUser testUser >> newUser testUser

85+ err23505 = PQException $ PQState FatalError (Just "23505")

86+ (Just "ERROR: duplicate key value violates unique constraint \"unique_names\"\nDETAIL: Key (name)=(TestUser) already exists.\n")

87+

88+ it "should be thrown for constraint violation" $

89+ withConnection connectionString insertUserTwice

90+ `shouldThrow` (== err23505)

91+

92+ it "should be rethrown for constraint violation in a transaction" $

93+ withConnection connectionString (transactionally_ insertUserTwice)

94+ `shouldThrow` (== err23505)

95+

96+ describe "Pools" $

97+

98+ it "should manage concurrent transactions" $ do

99+ pool <- createConnectionPool

100+ "host=localhost port=5432 dbname=exampledb" 1 0.5 10

101+ let

102+ query :: Query_ (Public '[]) () (Only Char)

103+ query = values_ (literal 'a' `as` #fromOnly)

104+ session = usingConnectionPool pool . transactionally_ $ do

105+ result <- runQuery query

106+ Just (Only chr) <- firstRow result

107+ return chr

108+ chrs <- replicateConcurrently 10 session

109+ chrs `shouldSatisfy` all (== 'a')

110+

111+ describe "Ranges" $

112+

113+ it "should correctly decode ranges" $ do

114+

115+ rangesOut <- withConnection connectionString $ do

116+ let

117+ query :: Query_ (Public '[]) () (Only (Range Int32))

118+ query = values

119+ ( range int4range (atLeast 3) `as` #fromOnly )

120+ [ range int4range (3 <=..< 5) `as` #fromOnly

121+ , range int4range Empty `as` #fromOnly

122+ , range int4range whole `as` #fromOnly ]

123+ getRows =<< runQuery query

124+ (fromOnly <$> rangesOut :: [Range Int32]) `shouldBe`

125+ [ atLeast 3, 3 <=..< 5, Empty, whole ]

126+

127+ describe "Parameters" $ do

128+

129+ it "should run queries that don't reference all their parameters" $ do

130+

131+ out <- withConnection connectionString $ do

132+ let

133+ query :: Query_ (Public '[]) (Char,Int32) (Only Int32)

134+ query = values_ (param @2 `as` #fromOnly)

135+ firstRow =<< runQueryParams query ('a', 3 :: Int32)

136+ (fromOnly <$> out :: Maybe Int32) `shouldBe` Just 3

squeal-postgresql/test/Squeal/PostgreSQL/StatementSpec.hsdeleted−328

@@ -1,328 +0,0 @@

1−{-# LANGUAGE

2− DataKinds

3− , MagicHash

4− , OverloadedLabels

5− , OverloadedStrings

6− , TypeApplications

7− , TypeOperators

8−#-}

9−

10−module Squeal.PostgreSQL.StatementSpec where

11−

12−import Control.Category ((>>>))

13−import Data.Function

14−import Generics.SOP hiding (from)

15−import Test.Hspec

16−

17−import Squeal.PostgreSQL.Statement

18−import Squeal.PostgreSQL.Schema

19−

20−spec :: Spec

21−spec = do

22− let

23− qry `queryRenders` str = query qry `manipulationRenders` str

24− definition `definitionRenders` str =

25− renderDefinition definition `shouldBe` str

26− manipulation `manipulationRenders` str =

27− renderManipulation manipulation `shouldBe` str

28− it "correctly renders a simple SELECT query" $ do

29− let

30− statement :: Query Tables '[] SumAndCol1

31− statement =

32− select ((#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)

33− (from (Table (#table1 `As` #table1)) & where_ (#col1 >* #col2))

34− statement `queryRenders`

35− "SELECT (col1 + col2) AS sum, col1 AS col1\

36− \ FROM table1 AS table1 WHERE (col1 > col2);"

37− it "combines WHEREs using AND" $ do

38− let

39− statement :: Query Tables '[] SumAndCol1

40− statement =

41− select ((#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)

42− (from (Table (#table1 `As` #table1)) & where_ true & where_ false)

43− statement `queryRenders`

44− "SELECT (col1 + col2) AS sum, col1 AS col1\

45− \ FROM table1 AS table1 WHERE (TRUE AND FALSE);"

46− it "performs sub SELECTs" $ do

47− let

48− statement :: Query Tables '[] SumAndCol1

49− statement =

50− selectStar (from (Subquery

51− (select ((#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)

52− (from (Table (#table1 `As` #table1))) `As` #sub)))

53− statement `queryRenders`

54− "SELECT * FROM\

55− \ SELECT (col1 + col2) AS sum, col1 AS col1\

56− \ FROM table1 AS table1 AS sub;"

57− it "does LIMIT clauses" $ do

58− let

59− statement :: Query Tables '[] Columns

60− statement = selectStar (from (Table (#table1 `As` #table1)) & limit 1)

61− statement `queryRenders` "SELECT * FROM table1 AS table1 LIMIT 1;"

62− it "should use the minimum of given LIMITs" $ do

63− let

64− statement :: Query Tables '[] Columns

65− statement =

66− selectStar (from (Table (#table1 `As` #table1)) & limit 1 & limit 2)

67− statement `queryRenders` "SELECT * FROM table1 AS table1 LIMIT 1;"

68− it "should render parameters using $ signs" $ do

69− let

70− statement :: Query Tables '[ 'Required ('NotNull 'PGbool)] Columns

71− statement = selectStar

72− (from (Table (#table1 `As` #table1)) & where_ (param (Proxy @1)))

73− statement `queryRenders`

74− "SELECT * FROM table1 AS table1 WHERE ($1 :: bool);"

75− it "does OFFSET clauses" $ do

76− let

77− statement :: Query Tables '[] Columns

78− statement =

79− selectStar (from (Table (#table1 `As` #table1)) & offset 1)

80− statement `queryRenders` "SELECT * FROM table1 AS table1 OFFSET 1;"

81− it "should use the sum of given OFFSETs" $ do

82− let

83− statement :: Query Tables '[] Columns

84− statement = selectStar

85− (from (Table (#table1 `As` #table1)) & offset 1 & offset 2)

86− statement `queryRenders` "SELECT * FROM table1 AS table1 OFFSET 3;"

87− it "should render GROUP BY and HAVING clauses" $ do

88− let

89− statement :: Query Tables '[] SumAndCol1

90− statement =

91− select (sum_ #col2 `As` #sum :* #col1 `As` #col1 :* Nil)

92− ( from (Table (#table1 `As` #table1))

93− & group (By #col1 :* Nil)

94− & having ((#col1 + sum_ #col2) >* 1) )

95− statement `queryRenders`

96− "SELECT sum(col2) AS sum, col1 AS col1\

97− \ FROM table1 AS table1\

98− \ GROUP BY col1\

99− \ HAVING ((col1 + sum(col2)) > 1);"

100− it "correctly renders simple INSERTs" $ do

101− let

102− statement :: Manipulation Tables '[] '[]

103− statement =

104− insertInto #table1 (Values (2 `As` #col1 :* 4 `As` #col2 :* Nil) [])

105− Conflict (Returning Nil)

106− statement `manipulationRenders`

107− "INSERT INTO table1 (col1, col2) VALUES (2, 4);"

108− it "correctly renders returning INSERTs" $ do

109− let

110− statement :: Manipulation Tables '[] SumAndCol1

111− statement =

112− insertInto #table1 (Values (2 `As` #col1 :* 4 `As` #col2 :* Nil) [])

113− Conflict

114− (Returning $ (#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)

115− statement `manipulationRenders`

116− "INSERT INTO table1 (col1, col2) VALUES (2, 4)\

117− \ RETURNING (col1 + col2) AS sum, col1 AS col1;"

118− it "correctly renders simple UPDATEs" $ do

119− let

120− statement :: Manipulation Tables '[] '[]

121− statement =

122− update #table1 (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

123− (#col1 /=* #col2) (Returning Nil)

124− statement `manipulationRenders`

125− "UPDATE table1 SET col1 = 2\

126− \ WHERE (col1 <> col2);"

127− it "correctly renders returning UPDATEs" $ do

128− let

129− statement :: Manipulation Tables '[] SumAndCol1

130− statement =

131− update #table1 (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

132− (#col1 /=* #col2)

133− (Returning $ (#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)

134− statement `manipulationRenders`

135− "UPDATE table1 SET col1 = 2\

136− \ WHERE (col1 <> col2)\

137− \ RETURNING (col1 + col2) AS sum, col1 AS col1;"

138− it "correctly renders upsert INSERTs" $ do

139− let

140− statement :: Manipulation Tables '[] '[]

141− statement =

142− insertInto #table1 (Values (2 `As` #col1 :* 4 `As` #col2 :* Nil) [])

143− (OnConflictDoUpdate

144− (Set 2 `As` #col1 :* Same `As` #col2 :* Nil) (#col1 /=* #col2))

145− (Returning Nil)

146− statement `manipulationRenders`

147− "INSERT INTO table1 (col1, col2) VALUES (2, 4)\

148− \ ON CONFLICT DO UPDATE\

149− \ SET col1 = 2 WHERE (col1 <> col2);"

150− it "correctly renders returning upsert INSERTs" $ do

151− let

152− statement :: Manipulation Tables '[] SumAndCol1

153− statement =

154− insertInto #table1 (Values (2 `As` #col1 :* 4 `As` #col2 :* Nil) [])

155− (OnConflictDoUpdate

156− (Set 2 `As` #col1 :* Same `As` #col2 :* Nil)

157− (#col1 /=* #col2))

158− (Returning $ (#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)

159− statement `manipulationRenders`

160− "INSERT INTO table1 (col1, col2) VALUES (2, 4)\

161− \ ON CONFLICT DO UPDATE\

162− \ SET col1 = 2\

163− \ WHERE (col1 <> col2)\

164− \ RETURNING (col1 + col2) AS sum, col1 AS col1;"

165− it "correctly renders DELETEs" $ do

166− let

167− statement :: Manipulation Tables '[] '[]

168− statement = deleteFrom #table1 (#col1 ==* #col2)

169− statement `manipulationRenders`

170− "DELETE FROM table1 WHERE (col1 = col2);"

171− it "should be safe against SQL injection in literal text" $ do

172− let

173− statement :: Manipulation StudentsTable '[] '[]

174− statement = insertInto #students

175− (Values ("Robert'); DROP TABLE students;" `As` #name :* Nil) [])

176− Conflict (Returning Nil)

177− statement `manipulationRenders`

178− "INSERT INTO students (name) VALUES (E'Robert''); DROP TABLE students;');"

179− describe "JOINs" $ do

180− it "should render CROSS JOINs" $ do

181− let

182− statement :: Query JoinTables '[] ValueColumns

183− statement = select

184− ( (#orders &. #orderVal) `As` #orderVal

185− :* (#customers &. #customerVal) `As` #customerVal

186− :* (#shippers &. #shipperVal) `As` #shipperVal :* Nil)

187− ( from (Table (#orders `As` #orders)

188− & CrossJoin (Table (#customers `As` #customers))

189− & CrossJoin (Table (#shippers `As` #shippers))))

190− statement `queryRenders`

191− "SELECT\

192− \ orders.orderVal AS orderVal,\

193− \ customers.customerVal AS customerVal,\

194− \ shippers.shipperVal AS shipperVal\

195− \ FROM orders AS orders\

196− \ CROSS JOIN customers AS customers\

197− \ CROSS JOIN shippers AS shippers;"

198− it "should render INNER JOINs" $ do

199− let

200− statement :: Query JoinTables '[] ValueColumns

201− statement = select

202− ( (#orders &. #orderVal) `As` #orderVal

203− :* (#customers &. #customerVal) `As` #customerVal

204− :* (#shippers &. #shipperVal) `As` #shipperVal :* Nil)

205− ( from (Table (#orders `As` #orders)

206− & InnerJoin (Table (#customers `As` #customers))

207− ((#orders &. #customerID) ==* (#customers &. #customerID))

208− & InnerJoin (Table (#shippers `As` #shippers))

209− ((#orders &. #shipperID) ==* (#shippers &. #shipperID))))

210− statement `queryRenders`

211− "SELECT\

212− \ orders.orderVal AS orderVal,\

213− \ customers.customerVal AS customerVal,\

214− \ shippers.shipperVal AS shipperVal\

215− \ FROM orders AS orders\

216− \ INNER JOIN customers AS customers\

217− \ ON (orders.customerID = customers.customerID)\

218− \ INNER JOIN shippers AS shippers\

219− \ ON (orders.shipperID = shippers.shipperID);"

220− it "should render self JOINs" $ do

221− let

222− statement :: Query JoinTables '[] OrderColumns

223− statement = selectDotStar #orders1

224− (from (Table (#orders `As` #orders1)

225− & CrossJoin (Table (#orders `As` #orders2))))

226− statement `queryRenders`

227− "SELECT orders1.*\

228− \ FROM orders AS orders1\

229− \ CROSS JOIN orders AS orders2;"

230− it "should render CREATE TABLE statements" $ do

231− createTable #table1

232− ((int4 & notNull) `As` #col1 :* (int4 & notNull) `As` #col2 :* Nil)

233− [primaryKey (Column #col1 :* Column #col2 :* Nil)]

234− `definitionRenders`

235− "CREATE TABLE table1\

236− \ (col1 int4 NOT NULL, col2 int4 NOT NULL,\

237− \ PRIMARY KEY (col1, col2));"

238− createTable #table2

239− ( serial `As` #col1 :*

240− text `As` #col2 :*

241− (int8 & notNull & default_ 8) `As` #col3 :* Nil )

242− [check (#col3 >* 0)]

243− `definitionRenders`

244− "CREATE TABLE table2\

245− \ (col1 serial,\

246− \ col2 text,\

247− \ col3 int8 NOT NULL DEFAULT 8,\

248− \ CHECK ((col3 > 0)));"

249− let

250− statement :: Definition '[]

251− '[ "users" :::

252− '[ "id" ::: 'Optional ('NotNull 'PGint4)

253− , "username" ::: 'Required ('NotNull 'PGtext)

254− ]

255− , "emails" :::

256− '[ "id" ::: 'Optional ('NotNull 'PGint4)

257− , "userid" ::: 'Required ('NotNull 'PGint4)

258− , "email" ::: 'Required ('NotNull 'PGtext)

259− ]

260− ]

261− statement =

262− createTable #users

263− (serial `As` #id :* (text & notNull) `As` #username :* Nil)

264− [primaryKey (Column #id :* Nil)]

265− >>>

266− createTable #emails

267− ( serial `As` #id :*

268− (integer & notNull) `As` #userid :*

269− (text & notNull) `As` #email :* Nil )

270− [ primaryKey (Column #id :* Nil)

271− , foreignKey (Column #userid :* Nil) #users (Column #id :* Nil)

272− , unique (Column #email :* Nil)

273− , check (#email /=* "")

274− ]

275− statement `definitionRenders`

276− "CREATE TABLE users\

277− \ (id serial, username text NOT NULL,\

278− \ PRIMARY KEY (id));\

279− \ \

280− \CREATE TABLE emails\

281− \ (id serial,\

282− \ userid integer NOT NULL,\

283− \ email text NOT NULL,\

284− \ PRIMARY KEY (id),\

285− \ FOREIGN KEY (userid) REFERENCES users (id),\

286− \ UNIQUE (email),\

287− \ CHECK ((email <> E'')));"

288− it "should render DROP TABLE statements" $ do

289− let

290− statement :: Definition Tables '[]

291− statement = dropTable #table1

292− statement `definitionRenders` "DROP TABLE table1;"

293−

294−type Columns =

295− '[ "col1" ::: 'Required ('NotNull 'PGint4)

296− , "col2" ::: 'Required ('NotNull 'PGint4)

297− ]

298−type Tables = '[ "table1" ::: Columns ]

299−type SumAndCol1 =

300− '[ "sum" ::: 'Required ('NotNull 'PGint4)

301− , "col1" ::: 'Required ('NotNull 'PGint4)

302− ]

303−type StudentsColumns = '["name" ::: 'Required ('NotNull 'PGtext)]

304−type StudentsTable = '["students" ::: StudentsColumns]

305−type OrderColumns =

306− '[ "orderID" ::: 'Required ('NotNull 'PGint4)

307− , "orderVal" ::: 'Required ('NotNull 'PGtext)

308− , "customerID" ::: 'Required ('NotNull 'PGint4)

309− , "shipperID" ::: 'Required ('NotNull 'PGint4)

310− ]

311−type CustomerColumns =

312− '[ "customerID" ::: 'Required ('NotNull 'PGint4)

313− , "customerVal" ::: 'Required ('NotNull 'PGfloat4)

314− ]

315−type ShipperColumns =

316− '[ "shipperID" ::: 'Required ('NotNull 'PGint4)

317− , "shipperVal" ::: 'Required ('NotNull 'PGbool)

318− ]

319−type JoinTables =

320− '[ "orders" ::: OrderColumns

321− , "customers" ::: CustomerColumns

322− , "shippers" ::: ShipperColumns

323− ]

324−type ValueColumns =

325− '[ "orderVal" ::: 'Required ('NotNull 'PGtext)

326− , "customerVal" ::: 'Required ('NotNull 'PGfloat4)

327− , "shipperVal" ::: 'Required ('NotNull 'PGbool)

328− ]

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 !

squeal-presentation.pdfnew file

Binary file not shown.

stack.yaml+6−1

@@ -1,3 +1,8 @@

1−resolver: nightly-2017-08-15

1+resolver: nightly-2019-07-14

2packages:

3- squeal-postgresql

5+extra-deps:

6+- unliftio-pool-0.2.1.0

7+- github: morphismtech/free-categories

8+ commit: c0e555fbefb5c21619e532264c4dfeac556d0630