@@ -11,15 +11,13 @@ Squeal data definition language.
11{-# LANGUAGE
11{-# LANGUAGE
12 AllowAmbiguousTypes
12 AllowAmbiguousTypes
13 , ConstraintKinds
13 , ConstraintKinds
15 , DeriveGeneric
14 , DeriveGeneric
17 , FlexibleContexts
15 , FlexibleContexts
18 , FlexibleInstances
16 , FlexibleInstances
18+ , GeneralizedNewtypeDeriving
20 , LambdaCase
19 , LambdaCase
21 , MultiParamTypeClasses
20 , MultiParamTypeClasses
23 , OverloadedStrings
21 , OverloadedStrings
24 , RankNTypes
22 , RankNTypes
25 , ScopedTypeVariables
23 , ScopedTypeVariables
@@ -27,25 +25,84 @@ Squeal data definition language.
27 , TypeInType
25 , TypeInType
28 , TypeOperators
26 , TypeOperators
29 , UndecidableSuperClasses
27 , UndecidableSuperClasses
30− , UndecidableInstances
33module Squeal.PostgreSQL.Definition
30module Squeal.PostgreSQL.Definition
34 ( -- * Definition
31 ( -- * Definition
35 Definition (..)
32 Definition (..)
37− , manipDefinition
34+ -- * Tables
37+ , createSchemaIfNotExists
39+ , createTableIfNotExists
43+ , createTypeComposite
44+ , createTypeCompositeFrom
47+ , TableConstraintExpression (..)
53+ , OnDeleteClause (..)
54+ , OnUpdateClause (..)
77+ , ColumnTypeExpression (..)
40import Control.Category
89import Control.Category
41import Control.DeepSeq
90import Control.DeepSeq
42import Data.ByteString
91import Data.ByteString
43import Data.Monoid
92import Data.Monoid
44import Prelude hiding ((.), id)
94import Prelude hiding ((.), id)
96+import qualified Generics.SOP as SOP
46import qualified GHC.Generics as GHC
97import qualified GHC.Generics as GHC
48−import Squeal.PostgreSQL.Manipulation
99+import Squeal.PostgreSQL.Alias
100+import Squeal.PostgreSQL.Expression
101+import Squeal.PostgreSQL.Expression.Logic
102+import Squeal.PostgreSQL.Expression.Type
103+import Squeal.PostgreSQL.List
104+import Squeal.PostgreSQL.PG
105+import Squeal.PostgreSQL.Query
49import Squeal.PostgreSQL.Render
106import Squeal.PostgreSQL.Render
50import Squeal.PostgreSQL.Schema
107import Squeal.PostgreSQL.Schema
@@ -73,10 +130,971 @@ instance Category Definition where
73 ddl1 . ddl0 = UnsafeDefinition $
130 ddl1 . ddl0 = UnsafeDefinition $
74 renderSQL ddl0 <> "\n" <> renderSQL ddl1
131 renderSQL ddl0 <> "\n" <> renderSQL ddl1
76−-- | A `Manipulation` without input or output can be run as a statement
133+{-----------------------------------------
77−-- along with other `Definition`s, by embedding it using `manipDefinition`.
134+CREATE statements
78−manipDefinition
135+-----------------------------------------}
79− :: Manipulation '[] schemas '[] '[]
136+
80− -- ^ no input or output
137+{- |
138+`createSchema` enters a new schema into the current database.
139+The schema name must be distinct from the name of any existing schema
140+in the current database.
142+A schema is essentially a namespace: it contains named objects
143+(tables, data types, functions, and operators) whose names
144+can duplicate those of other objects existing in other schemas.
145+Named objects are accessed by `QualifiedAlias`es with the schema
151+ -> Definition schemas (Create sch '[] schemas)
152+createSchema sch = UnsafeDefinition $
153+ "CREATE" <+> "SCHEMA" <+> renderSQL sch <> ";"
155+{- | Idempotent version of `createSchema`. -}
156+createSchemaIfNotExists
157+ :: (KnownSymbol sch, Has sch schemas schema)
81 -> Definition schemas schemas
159 -> Definition schemas schemas
82−manipDefinition = UnsafeDefinition . (<> ";") . renderSQL
160+createSchemaIfNotExists sch = UnsafeDefinition $
161+ "CREATE" <+> "SCHEMA" <+> "IF" <+> "NOT" <+> "EXISTS"
162+ <+> renderSQL sch <> ";"
164+{- | `createTable` adds a table to the schema.
166+>>> :set -XOverloadedLabels
169+ '[ "a" ::: 'NoDef :=> 'Null 'PGint4
170+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]
175+ setup :: Definition (Public '[]) (Public '["tab" ::: 'Table Table])
176+ setup = createTable #tab
177+ (nullable int `as` #a :* nullable real `as` #b) Nil
180+CREATE TABLE "tab" ("a" int NULL, "b" real NULL);
183+ :: ( KnownSymbol sch
185+ , columns ~ (col ': cols)
186+ , SOP.SListI columns
187+ , SOP.SListI constraints
188+ , Has sch schemas0 schema0
189+ , schemas1 ~ Alter sch (Create tab ('Table (constraints :=> columns)) schema0) schemas0 )
190+ => QualifiedAlias sch tab -- ^ the name of the table to add
191+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns
192+ -- ^ the names and datatype of each column
193+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints
194+ -- ^ constraints that must hold for the table
195+ -> Definition schemas0 schemas1
196+createTable tab columns constraints = UnsafeDefinition $
197+ "CREATE TABLE" <+> renderCreation tab columns constraints
199+{-| `createTableIfNotExists` creates a table if it doesn't exist, but does not add it to the schema.
200+Instead, the schema already has the table so if the table did not yet exist, the schema was wrong.
201+`createTableIfNotExists` fixes this. Interestingly, this property makes it an idempotent in
202+the `Category` of `Definition`s.
204+>>> :set -XOverloadedLabels -XTypeApplications
207+ '[ "a" ::: 'NoDef :=> 'Null 'PGint4
208+ , "b" ::: 'NoDef :=> 'Null 'PGfloat4 ]
211+>>> type Schemas = Public '["tab" ::: 'Table Table]
215+ setup :: Definition Schemas Schemas
216+ setup = createTableIfNotExists #tab
217+ (nullable int `as` #a :* nullable real `as` #b) Nil
220+CREATE TABLE IF NOT EXISTS "tab" ("a" int NULL, "b" real NULL);
222+createTableIfNotExists
223+ :: ( Has sch schemas schema
224+ , Has tab schema ('Table (constraints :=> columns))
225+ , SOP.SListI columns
226+ , SOP.SListI constraints )
227+ => QualifiedAlias sch tab -- ^ the name of the table to add
228+ -> NP (Aliased (ColumnTypeExpression schemas)) columns
229+ -- ^ the names and datatype of each column
230+ -> NP (Aliased (TableConstraintExpression sch tab schemas)) constraints
231+ -- ^ constraints that must hold for the table
232+ -> Definition schemas schemas
233+createTableIfNotExists tab columns constraints = UnsafeDefinition $
234+ "CREATE TABLE IF NOT EXISTS"
235+ <+> renderCreation tab columns constraints
237+-- helper function for `createTable` and `createTableIfNotExists`
239+ :: ( KnownSymbol sch
241+ , SOP.SListI columns
242+ , SOP.SListI constraints )
243+ => QualifiedAlias sch tab -- ^ the name of the table to add
244+ -> NP (Aliased (ColumnTypeExpression schemas0)) columns
245+ -- ^ the names and datatype of each column
246+ -> NP (Aliased (TableConstraintExpression sch tab schemas1)) constraints
247+ -- ^ constraints that must hold for the table
249+renderCreation tab columns constraints = renderSQL tab
251+ ( renderCommaSeparated renderColumnDef columns
252+ <> ( case constraints of
255+ renderCommaSeparated renderConstraint constraints ) )
258+ renderColumnDef :: Aliased (ColumnTypeExpression schemas) x -> ByteString
259+ renderColumnDef (ty `As` column) =
260+ renderSQL column <+> renderColumnTypeExpression ty
262+ :: Aliased (TableConstraintExpression sch tab schemas) constraint
264+ renderConstraint (constraint `As` alias) =
265+ "CONSTRAINT" <+> renderSQL alias <+> renderSQL constraint
267+-- | Data types are a way to limit the kind of data that can be stored in a
268+-- table. For many applications, however, the constraint they provide is
269+-- too coarse. For example, a column containing a product price should
270+-- probably only accept positive values. But there is no standard data type
271+-- that accepts only positive numbers. Another issue is that you might want
272+-- to constrain column data with respect to other columns or rows.
273+-- For example, in a table containing product information,
274+-- there should be only one row for each product number.
275+-- `TableConstraint`s give you as much control over the data in your tables
276+-- as you wish. If a user attempts to store data in a column that would
277+-- violate a constraint, an error is raised. This applies
278+-- even if the value came from the default value definition.
279+newtype TableConstraintExpression
282+ (schemas :: SchemasType)
283+ (constraint :: TableConstraint)
284+ = UnsafeTableConstraintExpression
285+ { renderTableConstraintExpression :: ByteString }
286+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
288+ (TableConstraintExpression sch tab schemas constraint) where
289+ renderSQL = renderTableConstraintExpression
291+{-| A `check` constraint is the most generic `TableConstraint` type.
292+It allows you to specify that the value in a certain column must satisfy
293+a Boolean (truth-value) expression.
297+ "tab" ::: 'Table ('[ "inequality" ::: 'Check '["a","b"]] :=> '[
298+ "a" ::: 'NoDef :=> 'NotNull 'PGint4,
299+ "b" ::: 'NoDef :=> 'NotNull 'PGint4
305+ definition :: Definition (Public '[]) (Public Schema)
306+ definition = createTable #tab
307+ ( (int & notNullable) `as` #a :*
308+ (int & notNullable) `as` #b )
309+ ( check (#a :* #b) (#a .> #b) `as` #inequality )
312+>>> printSQL definition
313+CREATE TABLE "tab" ("a" int NOT NULL, "b" int NOT NULL, CONSTRAINT "inequality" CHECK (("a" > "b")));
316+ :: ( Has sch schemas schema
317+ , Has tab schema ('Table table)
318+ , HasAll aliases (TableToRow table) subcolumns )
320+ -- ^ specify the subcolumns which are getting checked
321+ -> (forall t. Condition '[] '[] 'Ungrouped schemas '[] '[t ::: subcolumns])
322+ -- ^ a closed `Condition` on those subcolumns
323+ -> TableConstraintExpression sch tab schemas ('Check aliases)
324+check _cols condition = UnsafeTableConstraintExpression $
325+ "CHECK" <+> parenthesized (renderSQL condition)
327+{-| A `unique` constraint ensure that the data contained in a column,
328+or a group of columns, is unique among all the rows in the table.
332+ "tab" ::: 'Table( '[ "uq_a_b" ::: 'Unique '["a","b"]] :=> '[
333+ "a" ::: 'NoDef :=> 'Null 'PGint4,
334+ "b" ::: 'NoDef :=> 'Null 'PGint4
340+ definition :: Definition (Public '[]) (Public Schema)
341+ definition = createTable #tab
342+ ( (int & nullable) `as` #a :*
343+ (int & nullable) `as` #b )
344+ ( unique (#a :* #b) `as` #uq_a_b )
347+>>> printSQL definition
348+CREATE TABLE "tab" ("a" int NULL, "b" int NULL, CONSTRAINT "uq_a_b" UNIQUE ("a", "b"));
351+ :: ( Has sch schemas schema
352+ , Has tab schema('Table table)
353+ , HasAll aliases (TableToRow table) subcolumns )
355+ -- ^ specify subcolumns which together are unique for each row
356+ -> TableConstraintExpression sch tab schemas ('Unique aliases)
357+unique columns = UnsafeTableConstraintExpression $
358+ "UNIQUE" <+> parenthesized (renderSQL columns)
360+{-| A `primaryKey` constraint indicates that a column, or group of columns,
361+can be used as a unique identifier for rows in the table.
362+This requires that the values be both unique and not null.
366+ "tab" ::: 'Table ('[ "pk_id" ::: 'PrimaryKey '["id"]] :=> '[
367+ "id" ::: 'Def :=> 'NotNull 'PGint4,
368+ "name" ::: 'NoDef :=> 'NotNull 'PGtext
374+ definition :: Definition (Public '[]) (Public Schema)
375+ definition = createTable #tab
376+ ( serial `as` #id :*
377+ (text & notNullable) `as` #name )
378+ ( primaryKey #id `as` #pk_id )
381+>>> printSQL definition
382+CREATE TABLE "tab" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_id" PRIMARY KEY ("id"));
385+ :: ( Has sch schemas schema
386+ , Has tab schema ('Table table)
387+ , HasAll aliases (TableToColumns table) subcolumns
388+ , AllNotNull subcolumns )
390+ -- ^ specify the subcolumns which together form a primary key.
391+ -> TableConstraintExpression sch tab schemas ('PrimaryKey aliases)
392+primaryKey columns = UnsafeTableConstraintExpression $
393+ "PRIMARY KEY" <+> parenthesized (renderSQL columns)
395+{-| A `foreignKey` specifies that the values in a column
396+(or a group of columns) must match the values appearing in some row of
397+another table. We say this maintains the referential integrity
398+between two related tables.
402+ '[ "users" ::: 'Table (
403+ '[ "pk_users" ::: 'PrimaryKey '["id"] ] :=>
404+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
405+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
407+ , "emails" ::: 'Table (
408+ '[ "pk_emails" ::: 'PrimaryKey '["id"]
409+ , "fk_user_id" ::: 'ForeignKey '["user_id"] "users" '["id"]
411+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
412+ , "user_id" ::: 'NoDef :=> 'NotNull 'PGint4
413+ , "email" ::: 'NoDef :=> 'Null 'PGtext
420+ setup :: Definition (Public '[]) (Public Schema)
423+ ( serial `as` #id :*
424+ (text & notNullable) `as` #name )
425+ ( primaryKey #id `as` #pk_users ) >>>
427+ ( serial `as` #id :*
428+ (int & notNullable) `as` #user_id :*
429+ (text & nullable) `as` #email )
430+ ( primaryKey #id `as` #pk_emails :*
431+ foreignKey #user_id #users #id
432+ OnDeleteCascade OnUpdateCascade `as` #fk_user_id )
435+CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));
436+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);
438+A `foreignKey` can even be a table self-reference.
442+ '[ "employees" ::: 'Table (
443+ '[ "employees_pk" ::: 'PrimaryKey '["id"]
444+ , "employees_employer_fk" ::: 'ForeignKey '["employer_id"] "employees" '["id"]
446+ '[ "id" ::: 'Def :=> 'NotNull 'PGint4
447+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
448+ , "employer_id" ::: 'NoDef :=> 'Null 'PGint4
455+ setup :: Definition (Public '[]) (Public Schema)
457+ createTable #employees
458+ ( serial `as` #id :*
459+ (text & notNullable) `as` #name :*
460+ (integer & nullable) `as` #employer_id )
461+ ( primaryKey #id `as` #employees_pk :*
462+ foreignKey #employer_id #employees #id
463+ OnDeleteCascade OnUpdateCascade `as` #employees_employer_fk )
466+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);
469+ :: (ForeignKeyed schemas sch schema child parent
475+ -- ^ column or columns in the table
477+ -- ^ reference table
478+ -> NP Alias refcolumns
479+ -- ^ reference column or columns in the reference table
481+ -- ^ what to do when reference is deleted
483+ -- ^ what to do when reference is updated
484+ -> TableConstraintExpression sch child schemas
485+ ('ForeignKey columns parent refcolumns)
486+foreignKey keys parent refs ondel onupd = UnsafeTableConstraintExpression $
487+ "FOREIGN KEY" <+> parenthesized (renderSQL keys)
488+ <+> "REFERENCES" <+> renderSQL parent
489+ <+> parenthesized (renderSQL refs)
493+-- | A constraint synonym between types involved in a foreign key constraint.
494+type ForeignKeyed schemas
502+ ( Has sch schemas schema
503+ , Has child schema ('Table table)
504+ , Has parent schema ('Table reftable)
505+ , HasAll columns (TableToColumns table) tys
506+ , reftable ~ (constraints :=> cols)
507+ , HasAll refcolumns cols reftys
508+ , SOP.AllZip SamePGType tys reftys
509+ , Uniquely refcolumns constraints )
511+-- | `OnDeleteClause` indicates what to do with rows that reference a deleted row.
514+ -- ^ if any referencing rows still exist when the constraint is checked,
515+ -- an error is raised
516+ | OnDeleteRestrict -- ^ prevents deletion of a referenced row
518+ -- ^ specifies that when a referenced row is deleted,
519+ -- row(s) referencing it should be automatically deleted as well
520+ deriving (GHC.Generic,Show,Eq,Ord)
521+instance NFData OnDeleteClause
522+-- | Render `OnDeleteClause`.
523+instance RenderSQL OnDeleteClause where
525+ OnDeleteNoAction -> "ON DELETE NO ACTION"
526+ OnDeleteRestrict -> "ON DELETE RESTRICT"
527+ OnDeleteCascade -> "ON DELETE CASCADE"
529+-- | Analagous to `OnDeleteClause` there is also `OnUpdateClause` which is invoked
530+-- when a referenced column is changed (updated).
533+ -- ^ if any referencing rows has not changed when the constraint is checked,
534+ -- an error is raised
535+ | OnUpdateRestrict -- ^ prevents update of a referenced row
537+ -- ^ the updated values of the referenced column(s) should be copied
538+ -- into the referencing row(s)
539+ deriving (GHC.Generic,Show,Eq,Ord)
540+instance NFData OnUpdateClause
542+-- | Render `OnUpdateClause`.
543+instance RenderSQL OnUpdateClause where
545+ OnUpdateNoAction -> "ON UPDATE NO ACTION"
546+ OnUpdateRestrict -> "ON UPDATE RESTRICT"
547+ OnUpdateCascade -> "ON UPDATE CASCADE"
549+{-----------------------------------------
551+-----------------------------------------}
555+-- definition :: Definition '["muh_schema" ::: schema, "public" ::: public] '["public" ::: public]
556+-- definition = dropSchema #muh_schema
559+-- >>> printSQL definition
560+-- DROP SCHEMA "muh_schema";
562+ :: Has sch schemas schema
564+ -> Definition schemas (Drop sch schemas)
565+dropSchema sch = UnsafeDefinition $ "DROP SCHEMA" <+> renderSQL sch <> ";"
567+-- | `dropTable` removes a table from the schema.
571+-- definition :: Definition '["public" ::: '["muh_table" ::: 'Table t]] (Public '[])
572+-- definition = dropTable #muh_table
575+-- >>> printSQL definition
576+-- DROP TABLE "muh_table";
578+ :: ( Has sch schemas schema
579+ , Has tab schema ('Table table))
580+ => QualifiedAlias sch tab -- ^ table to remove
581+ -> Definition schemas (Alter sch (Drop tab schema) schemas)
582+dropTable tab = UnsafeDefinition $ "DROP TABLE" <+> renderSQL tab <> ";"
584+{-----------------------------------------
586+-----------------------------------------}
588+-- | `alterTable` changes the definition of a table from the schema.
590+ :: (Has sch schemas schema, Has tab schema ('Table table0))
591+ => QualifiedAlias sch tab -- ^ table to alter
592+ -> AlterTable sch tab schemas table1 -- ^ alteration to perform
593+ -> Definition schemas (Alter sch (Alter tab ('Table table1) schema) schemas)
594+alterTable tab alteration = UnsafeDefinition $
597+ <+> renderAlterTable alteration
600+-- | `alterTableRename` changes the name of a table from the schema.
602+-- >>> printSQL $ alterTableRename #foo #bar
603+-- ALTER TABLE "foo" RENAME TO "bar";
605+ :: (KnownSymbol table0, KnownSymbol table1)
606+ => Alias table0 -- ^ table to rename
607+ -> Alias table1 -- ^ what to rename it
608+ -> Definition schema (Rename table0 table1 schema)
609+alterTableRename table0 table1 = UnsafeDefinition $
610+ "ALTER TABLE" <+> renderSQL table0
611+ <+> "RENAME TO" <+> renderSQL table1 <> ";"
613+-- | An `AlterTable` describes the alteration to perform on the columns
618+ (schemas :: SchemasType)
619+ (table :: TableType) =
620+ UnsafeAlterTable {renderAlterTable :: ByteString}
621+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
623+-- | An `addConstraint` adds a table constraint.
627+-- definition :: Definition
628+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
629+-- '["public" ::: '["tab" ::: 'Table ('["positive" ::: 'Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
630+-- definition = alterTable #tab (addConstraint #positive (check #col (#col .> 0)))
631+-- in printSQL definition
633+-- ALTER TABLE "tab" ADD CONSTRAINT "positive" CHECK (("col" > 0));
635+ :: ( KnownSymbol alias
636+ , Has sch schemas schema
637+ , Has tab schema ('Table table0)
638+ , table0 ~ (constraints :=> columns)
639+ , table1 ~ (Create alias constraint constraints :=> columns) )
641+ -> TableConstraintExpression sch tab schemas constraint
642+ -- ^ constraint to add
643+ -> AlterTable sch tab schemas table1
644+addConstraint alias constraint = UnsafeAlterTable $
645+ "ADD" <+> "CONSTRAINT" <+> renderSQL alias
646+ <+> renderSQL constraint
648+-- | A `dropConstraint` drops a table constraint.
652+-- definition :: Definition
653+-- '["public" ::: '["tab" ::: 'Table ('["positive" ::: Check '["col"]] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
654+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
655+-- definition = alterTable #tab (dropConstraint #positive)
656+-- in printSQL definition
658+-- ALTER TABLE "tab" DROP CONSTRAINT "positive";
660+ :: ( KnownSymbol constraint
661+ , Has sch schemas schema
662+ , Has tab schema ('Table table0)
663+ , table0 ~ (constraints :=> columns)
664+ , table1 ~ (Drop constraint constraints :=> columns) )
666+ -- ^ constraint to drop
667+ -> AlterTable sch tab schemas table1
668+dropConstraint constraint = UnsafeAlterTable $
669+ "DROP" <+> "CONSTRAINT" <+> renderSQL constraint
671+-- | An `AddColumn` is either @NULL@ or has @DEFAULT@.
672+class AddColumn ty where
673+ -- | `addColumn` adds a new column, initially filled with whatever
674+ -- default value is given or with @NULL@.
678+ -- definition :: Definition
679+ -- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]
680+ -- '["public" ::: '["tab" ::: 'Table ('[] :=>
681+ -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
682+ -- , "col2" ::: 'Def :=> 'Null 'PGtext ])]]
683+ -- definition = alterTable #tab (addColumn #col2 (text & nullable & default_ "foo"))
684+ -- in printSQL definition
686+ -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL DEFAULT E'foo';
690+ -- definition :: Definition
691+ -- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]
692+ -- '["public" ::: '["tab" ::: 'Table ('[] :=>
693+ -- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
694+ -- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]]
695+ -- definition = alterTable #tab (addColumn #col2 (text & nullable))
696+ -- in printSQL definition
698+ -- ALTER TABLE "tab" ADD COLUMN "col2" text NULL;
700+ :: ( KnownSymbol column
701+ , Has sch schemas schema
702+ , Has tab schema ('Table table0)
703+ , table0 ~ (constraints :=> columns) )
704+ => Alias column -- ^ column to add
705+ -> ColumnTypeExpression schemas ty -- ^ type of the new column
706+ -> AlterTable sch tab schemas (constraints :=> Create column ty columns)
707+ addColumn column ty = UnsafeAlterTable $
708+ "ADD COLUMN" <+> renderSQL column <+> renderColumnTypeExpression ty
709+instance {-# OVERLAPPING #-} AddColumn ('Def :=> ty)
710+instance {-# OVERLAPPABLE #-} AddColumn ('NoDef :=> 'Null ty)
712+-- | A `dropColumn` removes a column. Whatever data was in the column
713+-- disappears. Table constraints involving the column are dropped, too.
714+-- However, if the column is referenced by a foreign key constraint of
715+-- another table, PostgreSQL will not silently drop that constraint.
719+-- definition :: Definition
720+-- '["public" ::: '["tab" ::: 'Table ('[] :=>
721+-- '[ "col1" ::: 'NoDef :=> 'Null 'PGint4
722+-- , "col2" ::: 'NoDef :=> 'Null 'PGtext ])]]
723+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col1" ::: 'NoDef :=> 'Null 'PGint4])]]
724+-- definition = alterTable #tab (dropColumn #col2)
725+-- in printSQL definition
727+-- ALTER TABLE "tab" DROP COLUMN "col2";
729+ :: ( KnownSymbol column
730+ , Has sch schemas schema
731+ , Has tab schema ('Table table0)
732+ , table0 ~ (constraints :=> columns)
733+ , table1 ~ (constraints :=> Drop column columns) )
734+ => Alias column -- ^ column to remove
735+ -> AlterTable sch tab schemas table1
736+dropColumn column = UnsafeAlterTable $
737+ "DROP COLUMN" <+> renderSQL column
739+-- | A `renameColumn` renames a column.
743+-- definition :: Definition
744+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["foo" ::: 'NoDef :=> 'Null 'PGint4])]]
745+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["bar" ::: 'NoDef :=> 'Null 'PGint4])]]
746+-- definition = alterTable #tab (renameColumn #foo #bar)
747+-- in printSQL definition
749+-- ALTER TABLE "tab" RENAME COLUMN "foo" TO "bar";
751+ :: ( KnownSymbol column0
752+ , KnownSymbol column1
753+ , Has sch schemas schema
754+ , Has tab schema ('Table table0)
755+ , table0 ~ (constraints :=> columns)
756+ , table1 ~ (constraints :=> Rename column0 column1 columns) )
757+ => Alias column0 -- ^ column to rename
758+ -> Alias column1 -- ^ what to rename the column
759+ -> AlterTable sch tab schemas table1
760+renameColumn column0 column1 = UnsafeAlterTable $
761+ "RENAME COLUMN" <+> renderSQL column0 <+> "TO" <+> renderSQL column1
763+-- | An `alterColumn` alters a single column.
765+ :: ( KnownSymbol column
766+ , Has sch schemas schema
767+ , Has tab schema ('Table table0)
768+ , table0 ~ (constraints :=> columns)
769+ , Has column columns ty0
770+ , table1 ~ (constraints :=> Alter column ty1 columns))
771+ => Alias column -- ^ column to alter
772+ -> AlterColumn schemas ty0 ty1 -- ^ alteration to perform
773+ -> AlterTable sch tab schemas table1
774+alterColumn column alteration = UnsafeAlterTable $
775+ "ALTER COLUMN" <+> renderSQL column <+> renderAlterColumn alteration
777+-- | An `AlterColumn` describes the alteration to perform on a single column.
778+newtype AlterColumn (schemas :: SchemasType) (ty0 :: ColumnType) (ty1 :: ColumnType) =
779+ UnsafeAlterColumn {renderAlterColumn :: ByteString}
780+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
782+-- | A `setDefault` sets a new default for a column. Note that this doesn't
783+-- affect any existing rows in the table, it just changes the default for
784+-- future insert and update commands.
788+-- definition :: Definition
789+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
790+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]]
791+-- definition = alterTable #tab (alterColumn #col (setDefault 5))
792+-- in printSQL definition
794+-- ALTER TABLE "tab" ALTER COLUMN "col" SET DEFAULT 5;
796+ :: Expression '[] '[] 'Ungrouped schemas '[] '[] ty -- ^ default value to set
797+ -> AlterColumn schemas (constraint :=> ty) ('Def :=> ty)
798+setDefault expression = UnsafeAlterColumn $
799+ "SET DEFAULT" <+> renderExpression expression
801+-- | A `dropDefault` removes any default value for a column.
805+-- definition :: Definition
806+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'Def :=> 'Null 'PGint4])]]
807+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
808+-- definition = alterTable #tab (alterColumn #col dropDefault)
809+-- in printSQL definition
811+-- ALTER TABLE "tab" ALTER COLUMN "col" DROP DEFAULT;
812+dropDefault :: AlterColumn schemas ('Def :=> ty) ('NoDef :=> ty)
813+dropDefault = UnsafeAlterColumn $ "DROP DEFAULT"
815+-- | A `setNotNull` adds a @NOT NULL@ constraint to a column.
816+-- The constraint will be checked immediately, so the table data must satisfy
817+-- the constraint before it can be added.
821+-- definition :: Definition
822+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
823+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
824+-- definition = alterTable #tab (alterColumn #col setNotNull)
825+-- in printSQL definition
827+-- ALTER TABLE "tab" ALTER COLUMN "col" SET NOT NULL;
829+ :: AlterColumn schemas (constraint :=> 'Null ty) (constraint :=> 'NotNull ty)
830+setNotNull = UnsafeAlterColumn $ "SET NOT NULL"
832+-- | A `dropNotNull` drops a @NOT NULL@ constraint from a column.
836+-- definition :: Definition
837+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
838+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]]
839+-- definition = alterTable #tab (alterColumn #col dropNotNull)
840+-- in printSQL definition
842+-- ALTER TABLE "tab" ALTER COLUMN "col" DROP NOT NULL;
844+ :: AlterColumn schemas (constraint :=> 'NotNull ty) (constraint :=> 'Null ty)
845+dropNotNull = UnsafeAlterColumn $ "DROP NOT NULL"
847+-- | An `alterType` converts a column to a different data type.
848+-- This will succeed only if each existing entry in the column can be
849+-- converted to the new type by an implicit cast.
853+-- definition :: Definition
854+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGint4])]]
855+-- '["public" ::: '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGnumeric])]]
857+-- alterTable #tab (alterColumn #col (alterType (numeric & notNullable)))
858+-- in printSQL definition
860+-- ALTER TABLE "tab" ALTER COLUMN "col" TYPE numeric NOT NULL;
861+alterType :: ColumnTypeExpression schemas ty -> AlterColumn schemas ty0 ty
862+alterType ty = UnsafeAlterColumn $ "TYPE" <+> renderColumnTypeExpression ty
865+>>> type ABC = '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4]
866+>>> type BC = '["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4]
869+ definition :: Definition
870+ '[ "public" ::: '["abc" ::: 'Table ('[] :=> ABC)]]
871+ '[ "public" ::: '["abc" ::: 'Table ('[] :=> ABC), "bc" ::: 'View BC]]
873+ createView #bc (select_ (#b :* #c) (from (table #abc)))
874+in printSQL definition
876+CREATE VIEW "bc" AS SELECT "b" AS "b", "c" AS "c" FROM "abc" AS "abc";
879+ :: (KnownSymbol sch, KnownSymbol vw, Has sch schemas schema)
880+ => QualifiedAlias sch vw -- ^ the name of the view to add
881+ -> Query '[] '[] schemas '[] view -- ^ query
882+ -> Definition schemas (Alter sch (Create vw ('View view) schema) schemas)
883+createView alias query = UnsafeDefinition $
884+ "CREATE" <+> "VIEW" <+> renderSQL alias <+> "AS"
885+ <+> renderQuery query <> ";"
891+-- definition :: Definition
892+-- '[ "public" ::: '["abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])
893+-- , "bc" ::: 'View ('["b" ::: 'Null 'PGint4, "c" ::: 'Null 'PGint4])]]
894+-- '[ "public" ::: '["abc" ::: 'Table ('[] :=> '["a" ::: 'NoDef :=> 'Null 'PGint4, "b" ::: 'NoDef :=> 'Null 'PGint4, "c" ::: 'NoDef :=> 'Null 'PGint4])]]
895+-- definition = dropView #bc
896+-- in printSQL definition
900+ :: (Has sch schemas schema, Has vw schema ('View view))
901+ => QualifiedAlias sch vw -- ^ view to remove
902+ -> Definition schemas (Alter sch (Drop vw schema) schemas)
903+dropView vw = UnsafeDefinition $ "DROP VIEW" <+> renderSQL vw <> ";"
905+-- | Enumerated types are created using the `createTypeEnum` command, for example
907+-- >>> printSQL $ (createTypeEnum #mood (label @"sad" :* label @"ok" :* label @"happy") :: Definition (Public '[]) '["public" ::: '["mood" ::: 'Typedef ('PGenum '["sad","ok","happy"])]])
908+-- CREATE TYPE "mood" AS ENUM ('sad', 'ok', 'happy');
910+ :: (KnownSymbol enum, Has sch schemas schema, SOP.All KnownSymbol labels)
911+ => QualifiedAlias sch enum
912+ -- ^ name of the user defined enumerated type
913+ -> NP PGlabel labels
914+ -- ^ labels of the enumerated type
915+ -> Definition schemas (Alter sch (Create enum ('Typedef ('PGenum labels)) schema) schemas)
916+createTypeEnum enum labels = UnsafeDefinition $
917+ "CREATE" <+> "TYPE" <+> renderSQL enum <+> "AS" <+> "ENUM" <+>
918+ parenthesized (renderSQL labels) <> ";"
920+-- | Enumerated types can also be generated from a Haskell type, for example
922+-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
923+-- >>> instance SOP.Generic Schwarma
924+-- >>> instance SOP.HasDatatypeInfo Schwarma
927+-- createSchwarma :: Definition (Public '[]) '["public" ::: '["schwarma" ::: 'Typedef (PG (Enumerated Schwarma))]]
928+-- createSchwarma = createTypeEnumFrom @Schwarma #schwarma
930+-- printSQL createSchwarma
932+-- CREATE TYPE "schwarma" AS ENUM ('Beef', 'Lamb', 'Chicken');
934+ :: forall hask sch enum schemas schema.
936+ , SOP.All KnownSymbol (LabelsPG hask)
938+ , Has sch schemas schema )
939+ => QualifiedAlias sch enum
940+ -- ^ name of the user defined enumerated type
941+ -> Definition schemas (Alter sch (Create enum ('Typedef (PG (Enumerated hask))) schema) schemas)
942+createTypeEnumFrom enum = createTypeEnum enum
943+ (SOP.hpure label :: NP PGlabel (LabelsPG hask))
945+{- | `createTypeComposite` creates a composite type. The composite type is
946+specified by a list of attribute names and data types.
949+type PGcomplex = 'PGcomposite
950+ '[ "real" ::: 'NotNull 'PGfloat8
951+ , "imaginary" ::: 'NotNull 'PGfloat8 ]
956+ setup :: Definition (Public '[]) '["public" ::: '["complex" ::: 'Typedef PGcomplex]]
957+ setup = createTypeComposite #complex
958+ (float8 `as` #real :* float8 `as` #imaginary)
961+CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
964+ :: (KnownSymbol ty, Has sch schemas schema, SOP.SListI fields)
965+ => QualifiedAlias sch ty
966+ -- ^ name of the user defined composite type
967+ -> NP (Aliased (TypeExpression schemas)) fields
968+ -- ^ list of attribute names and data types
969+ -> Definition schemas (Alter sch (Create ty ('Typedef ('PGcomposite fields)) schema) schemas)
970+createTypeComposite ty fields = UnsafeDefinition $
971+ "CREATE" <+> "TYPE" <+> renderSQL ty <+> "AS" <+> parenthesized
972+ (renderCommaSeparated renderField fields) <> ";"
974+ renderField :: Aliased (TypeExpression schemas) x -> ByteString
975+ renderField (typ `As` alias) =
976+ renderSQL alias <+> renderSQL typ
978+-- | Composite types can also be generated from a Haskell type, for example
980+-- >>> data Complex = Complex {real :: Double, imaginary :: Double} deriving GHC.Generic
981+-- >>> instance SOP.Generic Complex
982+-- >>> instance SOP.HasDatatypeInfo Complex
983+-- >>> type Schema = '["complex" ::: 'Typedef (PG (Composite Complex))]
986+-- createComplex :: Definition (Public '[]) (Public Schema)
987+-- createComplex = createTypeCompositeFrom @Complex #complex
989+-- printSQL createComplex
991+-- CREATE TYPE "complex" AS ("real" float8, "imaginary" float8);
992+createTypeCompositeFrom
993+ :: forall hask sch ty schemas schema.
994+ ( SOP.All (FieldTyped schemas) (RowPG hask)
996+ , Has sch schemas schema )
997+ => QualifiedAlias sch ty
998+ -- ^ name of the user defined composite type
999+ -> Definition schemas (Alter sch (Create ty ( 'Typedef (PG (Composite hask))) schema) schemas)
1000+createTypeCompositeFrom ty = createTypeComposite ty
1001+ (SOP.hcpure (SOP.Proxy :: SOP.Proxy (FieldTyped schemas)) fieldtype
1002+ :: NP (Aliased (TypeExpression schemas)) (RowPG hask))
1005+`createDomain` creates a new domain. A domain is essentially a data type
1006+with constraints (restrictions on the allowed set of values).
1008+Domains are useful for abstracting common constraints on fields
1009+into a single location for maintenance. For example, several tables might
1010+contain email address columns, all requiring the same `check` constraint
1011+to verify the address syntax. Define a domain rather than setting up
1012+each table's constraint individually.
1016+ createPositive :: Definition (Public '[]) (Public '["positive" ::: 'Typedef 'PGfloat4])
1017+ createPositive = createDomain #positive real (#value .> 0 .&& (#value & isNotNull))
1018+in printSQL createPositive
1020+CREATE DOMAIN "positive" AS real CHECK ((("value" > 0) AND "value" IS NOT NULL));
1023+ :: (Has sch schemas schema, KnownSymbol dom)
1024+ => QualifiedAlias sch dom
1025+ -> (forall nullity. TypeExpression schemas (nullity ty))
1026+ -> (forall tab. Condition '[] '[] 'Ungrouped schemas '[] '[tab ::: '["value" ::: 'Null ty]])
1027+ -> Definition schemas (Alter sch (Create alias ('Typedef ty) schema) schemas)
1028+createDomain dom ty condition =
1029+ UnsafeDefinition $ "CREATE DOMAIN" <+> renderSQL dom
1030+ <+> "AS" <+> renderTypeExpression ty
1031+ <+> "CHECK" <+> parenthesized (renderSQL condition) <> ";"
1033+-- | Lift `PGTyped` to a field
1034+class FieldTyped schemas ty where
1035+ fieldtype :: Aliased (TypeExpression schemas) ty
1036+instance (KnownSymbol alias, PGTyped schemas ty)
1037+ => FieldTyped schemas (alias ::: ty) where
1038+ fieldtype = pgtype `As` Alias
1042+-- >>> data Schwarma = Beef | Lamb | Chicken deriving GHC.Generic
1043+-- >>> instance SOP.Generic Schwarma
1044+-- >>> instance SOP.HasDatatypeInfo Schwarma
1045+-- >>> printSQL (dropType #schwarma :: Definition '["public" ::: '["schwarma" ::: 'Typedef (PG (Enumerated Schwarma))]] (Public '[]))
1046+-- DROP TYPE "schwarma";
1048+ :: (Has sch schemas schema, Has td schema ('Typedef ty))
1049+ => QualifiedAlias sch td
1050+ -- ^ name of the user defined type
1051+ -> Definition schemas (Alter sch (Drop td schema) schemas)
1052+dropType tydef = UnsafeDefinition $ "DROP" <+> "TYPE" <+> renderSQL tydef <> ";"
1054+-- | `ColumnTypeExpression`s are used in `createTable` commands.
1055+newtype ColumnTypeExpression (schemas :: SchemasType) (ty :: ColumnType)
1056+ = UnsafeColumnTypeExpression { renderColumnTypeExpression :: ByteString }
1057+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
1058+instance RenderSQL (ColumnTypeExpression schemas ty) where
1059+ renderSQL = renderColumnTypeExpression
1061+-- | used in `createTable` commands as a column constraint to note that
1062+-- @NULL@ may be present in a column
1064+ :: TypeExpression schemas (nullity ty)
1065+ -> ColumnTypeExpression schemas ('NoDef :=> 'Null ty)
1066+nullable ty = UnsafeColumnTypeExpression $ renderSQL ty <+> "NULL"
1068+-- | used in `createTable` commands as a column constraint to ensure
1069+-- @NULL@ is not present in a column
1071+ :: TypeExpression schemas (nullity ty)
1072+ -> ColumnTypeExpression schemas ('NoDef :=> 'NotNull ty)
1073+notNullable ty = UnsafeColumnTypeExpression $ renderSQL ty <+> "NOT NULL"
1075+-- | used in `createTable` commands as a column constraint to give a default
1077+ :: Expression '[] '[] 'Ungrouped schemas '[] '[] ty
1078+ -> ColumnTypeExpression schemas ('NoDef :=> ty)
1079+ -> ColumnTypeExpression schemas ('Def :=> ty)
1080+default_ x ty = UnsafeColumnTypeExpression $
1081+ renderSQL ty <+> "DEFAULT" <+> renderExpression x
1083+-- | not a true type, but merely a notational convenience for creating
1084+-- unique identifier columns with type `PGint2`
1085+serial2, smallserial
1086+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint2)
1087+serial2 = UnsafeColumnTypeExpression "serial2"
1088+smallserial = UnsafeColumnTypeExpression "smallserial"
1089+-- | not a true type, but merely a notational convenience for creating
1090+-- unique identifier columns with type `PGint4`
1092+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint4)
1093+serial4 = UnsafeColumnTypeExpression "serial4"
1094+serial = UnsafeColumnTypeExpression "serial"
1095+-- | not a true type, but merely a notational convenience for creating
1096+-- unique identifier columns with type `PGint8`
1098+ :: ColumnTypeExpression schemas ('Def :=> 'NotNull 'PGint8)
1099+serial8 = UnsafeColumnTypeExpression "serial8"
1100+bigserial = UnsafeColumnTypeExpression "bigserial"