@@ -1,7 +1,7 @@
2Module: Squeal.PostgreSQL.Query
2Module: Squeal.PostgreSQL.Query
3Description: Squeal queries
3Description: Squeal queries
4−Copyright: (c) Eitan Chatav, 2019
4+Copyright: (c) Eitan Chatav, 2017
5Maintainer: eitan@morphism.tech
5Maintainer: eitan@morphism.tech
6Stability: experimental
6Stability: experimental
@@ -9,81 +9,69 @@ Squeal queries.
11{-# LANGUAGE
11{-# LANGUAGE
12− ConstraintKinds
12+ DeriveGeneric
14 , FlexibleContexts
13 , FlexibleContexts
17 , GeneralizedNewtypeDeriving
15 , GeneralizedNewtypeDeriving
18 , LambdaCase
16 , LambdaCase
19− , MultiParamTypeClasses
21 , OverloadedStrings
17 , OverloadedStrings
22− , QuantifiedConstraints
23− , ScopedTypeVariables
24 , StandaloneDeriving
18 , StandaloneDeriving
27 , TypeInType
19 , TypeInType
28 , TypeOperators
20 , TypeOperators
30− , UndecidableInstances
33module Squeal.PostgreSQL.Query
23module Squeal.PostgreSQL.Query
34 ( -- * Queries
24 ( -- * Queries
35− Query_
25+ Query (UnsafeQuery, renderQuery)
50 , unionAll
27 , unionAll
51 , intersect
28 , intersect
52 , intersectAll
29 , intersectAll
54 , exceptAll
31 , exceptAll
55− -- ** With
32+ -- * Select
56− , With (..)
33+ , select
57− , CommonTableExpression (..)
34+ , selectDistinct
58− , withRecursive
35+ , selectStar
38+ , selectDistinctDotStar
59 -- * Table Expressions
40 -- * Table Expressions
60 , TableExpression (..)
41 , TableExpression (..)
42+ , renderTableExpression
67− -- * From Clauses
50+ -- * From
68 , FromClause (..)
51 , FromClause (..)
70 , subquery
53 , subquery
73 , crossJoin
55 , crossJoin
74 , innerJoin
56 , innerJoin
75 , leftOuterJoin
57 , leftOuterJoin
76 , rightOuterJoin
58 , rightOuterJoin
77 , fullOuterJoin
59 , fullOuterJoin
78 -- * Grouping
60 -- * Grouping
79− , By (..)
61+ , By (By, By2)
80− , GroupByClause (..)
62+ , renderBy
81− , HavingClause (..)
63+ , GroupByClause (NoGroups, Group)
64+ , renderGroupByClause
65+ , HavingClause (NoHaving, Having)
68+ , SortExpression (..)
69+ , renderSortExpression
84import Control.DeepSeq
72import Control.DeepSeq
85import Data.ByteString (ByteString)
73import Data.ByteString (ByteString)
86−import Data.Kind (Type)
74+import Data.Monoid hiding (All)
87import Data.String
75import Data.String
88import Data.Word
76import Data.Word
89import Generics.SOP hiding (from)
77import Generics.SOP hiding (from)
@@ -91,555 +79,358 @@ import GHC.TypeLits
92import qualified GHC.Generics as GHC
80import qualified GHC.Generics as GHC
94−import Squeal.PostgreSQL.Alias
95import Squeal.PostgreSQL.Expression
82import 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
101import Squeal.PostgreSQL.Render
83import Squeal.PostgreSQL.Render
102import Squeal.PostgreSQL.Schema
84import Squeal.PostgreSQL.Schema
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
112−The process of retrieving or the command to retrieve data from
113−a database is called a `Query`.
115−The general `Query` type is parameterized by
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`.
125− (commons :: FromType)
126− (schemas :: SchemasType)
127− (params :: [NullityType])
129− = UnsafeQuery { renderQuery :: ByteString }
130− deriving (GHC.Generic,Show,Eq,Ord,NFData)
131−instance RenderSQL (Query outer commons schemas params row) where renderSQL = renderQuery
134−The top level `Query_` type is parameterized by a @schemas@ `SchemasType`,
87+The process of retrieving or the command to retrieve data from a database
135−against which the query is type-checked, an input @parameters@ Haskell `Type`,
88+is called a `Query`. The `select`, `selectStar`, `selectDotStar`,
136−and an ouput row Haskell `Type`.
89+`selectDistinct`, `selectDistinctStar` and `selectDistinctDotStar` commands
137−
90+are used to specify queries.
138−A top-level query can be run
139−using `Squeal.PostgreSQL.PQ.runQueryParams`, or if @parameters = ()@
140−using `Squeal.PostgreSQL.PQ.runQuery`.
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.
147−Let's see some examples of queries.
149−>>> :set -XDeriveAnyClass -XDerivingStrategies
151−data Row a b = Row { col1 :: a, col2 :: b }
152− deriving stock (GHC.Generic)
153− deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
156simple query:
92simple query:
158−>>> type Columns = '["col1" ::: 'NoDef :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]
159−>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
162− query :: Query_ (Public Schema) () (Row Int32 Int32)
96+ query :: Query
163− query = select Star (from (table #tab))
97+ '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
164−in printSQL query
98+ '[]
99+ '["col" ::: 'Null 'PGint4]
100+ query = selectStar (from (table #tab))
166−SELECT * FROM "tab" AS "tab"
103+"SELECT * FROM \"tab\" AS \"tab\""
168restricted query:
105restricted query:
172− query :: Query_ (Public Schema) () (Row Int32 Int32)
109+ query :: Query
110+ '[ "tab" ::: 'Table ('[] :=>
111+ '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
112+ , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]
114+ '[ "sum" ::: 'NotNull 'PGint4
115+ , "col1" ::: 'NotNull 'PGint4 ]
174− select_ ((#col1 + #col2) `as` #col1 :* #col1 `as` #col2)
117+ select
118+ ((#col1 + #col2) `As` #sum :* #col1 :* Nil)
175 ( from (table #tab)
119 ( from (table #tab)
176 & where_ (#col1 .> #col2)
120 & where_ (#col1 .> #col2)
177 & where_ (#col2 .> 0) )
121 & where_ (#col2 .> 0) )
178−in printSQL query
122+in renderQuery query
180−SELECT ("col1" + "col2") AS "col1", "col1" AS "col2" FROM "tab" AS "tab" WHERE (("col1" > "col2") AND ("col2" > 0))
124+"SELECT (\"col1\" + \"col2\") AS \"sum\", \"col1\" AS \"col1\" FROM \"tab\" AS \"tab\" WHERE ((\"col1\" > \"col2\") AND (\"col2\" > 0))"
186− query :: Query_ (Public Schema) () (Row Int32 Int32)
130+ query :: Query
187− query = select Star (from (subquery (select Star (from (table #tab)) `as` #sub)))
131+ '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
188−in printSQL query
132+ '[]
133+ '["col" ::: 'Null 'PGint4]
136+ (from (subquery (selectStar (from (table #tab)) `As` #sub)))
190−SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"
139+"SELECT * FROM (SELECT * FROM \"tab\" AS \"tab\") AS \"sub\""
192limits and offsets:
141limits and offsets:
196− query :: Query_ (Public Schema) () (Row Int32 Int32)
145+ query :: Query
197− query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)
146+ '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
198−in printSQL query
147+ '[]
148+ '["col" ::: 'Null 'PGint4]
150+ (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)
200−SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4
153+"SELECT * FROM \"tab\" AS \"tab\" LIMIT 50 OFFSET 4"
202parameterized query:
155parameterized query:
206− query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)
159+ query :: Query
207− query = select Star (from (table #tab) & where_ (#col1 .> param @1))
160+ '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8])]
208−in printSQL query
161+ '[ 'NotNull 'PGfloat8]
162+ '["col" ::: 'NotNull 'PGfloat8]
164+ (from (table #tab) & where_ (#col .> param @1))
210−SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))
167+"SELECT * FROM \"tab\" AS \"tab\" WHERE (\"col\" > ($1 :: float8))"
212aggregation query:
169aggregation query:
216− query :: Query_ (Public Schema) () (Row Int64 Int32)
173+ query :: Query
174+ '[ "tab" ::: 'Table ('[] :=>
175+ '[ "col1" ::: 'NoDef :=> 'NotNull 'PGint4
176+ , "col2" ::: 'NoDef :=> 'NotNull 'PGint4 ])]
178+ '[ "sum" ::: 'NotNull 'PGint4
179+ , "col1" ::: 'NotNull 'PGint4 ]
218− select_ ((fromNull 0 (sum_ (All #col2))) `as` #col1 :* #col1 `as` #col2)
181+ select (sum_ #col2 `As` #sum :* #col1 :* Nil)
219− ( from (table (#tab `as` #table1))
182+ ( from (table (#tab `As` #table1))
220− & groupBy #col1
183+ & group (By #col1 :* Nil)
221− & having (sum_ (Distinct #col2) .> 1) )
184+ & having (#col1 + sum_ #col2 .> 1) )
222−in printSQL query
185+in renderQuery query
224−SELECT COALESCE(sum(ALL "col2"), 0) AS "col1", "col1" AS "col2" FROM "tab" AS "table1" GROUP BY "col1" HAVING (sum(DISTINCT "col2") > 1)
187+"SELECT sum(\"col2\") AS \"sum\", \"col1\" AS \"col1\" FROM \"tab\" AS \"table1\" GROUP BY \"col1\" HAVING ((\"col1\" + sum(\"col2\")) > 1)"
226sorted query:
189sorted query:
230− query :: Query_ (Public Schema) () (Row Int32 Int32)
193+ query :: Query
231− query = select Star (from (table #tab) & orderBy [#col1 & Asc])
194+ '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
232−in printSQL query
195+ '[]
196+ '["col" ::: 'Null 'PGint4]
198+ (from (table #tab) & orderBy [#col & AscNullsFirst])
234−SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC
201+"SELECT * FROM \"tab\" AS \"tab\" ORDER BY \"col\" ASC NULLS FIRST"
238−>>> :{
205+>>> :set -XFlexibleContexts
240− '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
241− , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4
242− , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4
243− , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4 ]
247−type OrdersConstraints =
248− '["pk_orders" ::: PrimaryKey '["id"]
249− ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]
250− ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"] ]
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"]]
258− '[ "orders" ::: 'Table (OrdersConstraints :=> OrdersColumns)
259− , "customers" ::: 'Table (CustomersConstraints :=> NamesColumns)
260− , "shippers" ::: 'Table (ShippersConstraints :=> NamesColumns) ]
266− , customerName :: Text
267− , shipperName :: Text
268− } deriving GHC.Generic
269−instance SOP.Generic Order
270−instance SOP.HasDatatypeInfo Order
275− query :: Query_ (Public OrdersSchema) () Order
208+ query :: Query
276− query = select_
209+ '[ "orders" ::: 'Table (
277− ( #o ! #price `as` #price :*
210+ '["pk_orders" ::: PrimaryKey '["id"]
278− #c ! #name `as` #customerName :*
211+ ,"fk_customers" ::: ForeignKey '["customer_id"] "customers" '["id"]
279− #s ! #name `as` #shipperName )
212+ ,"fk_shippers" ::: ForeignKey '["shipper_id"] "shippers" '["id"]] :=>
280− ( from (table (#orders `as` #o)
213+ '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
281− & innerJoin (table (#customers `as` #c))
214+ , "price" ::: 'NoDef :=> 'NotNull 'PGfloat4
215+ , "customer_id" ::: 'NoDef :=> 'NotNull 'PGint4
216+ , "shipper_id" ::: 'NoDef :=> 'NotNull 'PGint4
218+ , "customers" ::: 'Table (
219+ '["pk_customers" ::: PrimaryKey '["id"]] :=>
220+ '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
221+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
223+ , "shippers" ::: 'Table (
224+ '["pk_shippers" ::: PrimaryKey '["id"]] :=>
225+ '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
226+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
230+ '[ "order_price" ::: 'NotNull 'PGfloat4
231+ , "customer_name" ::: 'NotNull 'PGtext
232+ , "shipper_name" ::: 'NotNull 'PGtext
235+ ( #o ! #price `As` #order_price :*
236+ #c ! #name `As` #customer_name :*
237+ #s ! #name `As` #shipper_name :* Nil )
238+ ( from (table (#orders `As` #o)
239+ & innerJoin (table (#customers `As` #c))
282 (#o ! #customer_id .== #c ! #id)
240 (#o ! #customer_id .== #c ! #id)
283− & innerJoin (table (#shippers `as` #s))
241+ & innerJoin (table (#shippers `As` #s))
284 (#o ! #shipper_id .== #s ! #id)) )
242 (#o ! #shipper_id .== #s ! #id)) )
285−in printSQL query
243+in renderQuery query
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")
245+"SELECT \"o\".\"price\" AS \"order_price\", \"c\".\"name\" AS \"customer_name\", \"s\".\"name\" AS \"shipper_name\" FROM \"orders\" AS \"o\" INNER JOIN \"customers\" AS \"c\" ON (\"o\".\"customer_id\" = \"c\".\"id\") INNER JOIN \"shippers\" AS \"s\" ON (\"o\".\"shipper_id\" = \"s\".\"id\")"
289self-join:
247self-join:
293− query :: Query_ (Public Schema) () (Row Int32 Int32)
251+ query :: Query
294− query = select
252+ '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
295− (#t1 & DotStar)
253+ '[]
296− (from (table (#tab `as` #t1) & crossJoin (table (#tab `as` #t2))))
254+ '["col" ::: 'Null 'PGint4]
297−in printSQL query
255+ query = selectDotStar #t1
298−:}
256+ (from (table (#tab `As` #t1) & crossJoin (table (#tab `As` #t2))))
299−SELECT "t1".* FROM "tab" AS "t1" CROSS JOIN "tab" AS "t2"
257+in renderQuery query
305− query :: Query_ schemas () (Row String Bool)
307− ("true" `as` #col1 :* true `as` #col2)
308− ["false" `as` #col1 :* false `as` #col2]
311−SELECT * FROM (VALUES (E'true', TRUE), (E'false', FALSE)) AS t ("col1", "col2")
259+"SELECT \"t1\".* FROM \"tab\" AS \"t1\" CROSS JOIN \"tab\" AS \"t2\""
313set operations:
261set operations:
317− query :: Query_ (Public Schema) () (Row Int32 Int32)
265+ query :: Query
318− query = select Star (from (table #tab)) `unionAll` select Star (from (table #tab))
266+ '["tab" ::: 'Table ('[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4])]
319−in printSQL query
267+ '[]
320−:}
268+ '["col" ::: 'Null 'PGint4]
321−(SELECT * FROM "tab" AS "tab") UNION ALL (SELECT * FROM "tab" AS "tab")
327− query :: Query_ (Public Schema) () (Row Int32 Int32)
329− select Star (from (table #tab)) `as` #cte1 :>>
330− select Star (from (common #cte1)) `as` #cte2
331− ) (select Star (from (common #cte2)))
334−WITH "cte1" AS (SELECT * FROM "tab" AS "tab"), "cte2" AS (SELECT * FROM "cte1" AS "cte1") SELECT * FROM "cte2" AS "cte2"
336−window function queries
340− query :: Query_ (Public Schema) () (Row Int32 Int64)
342− (#col1 & Also (rank `as` #col2 `Over` (partitionBy #col1 & orderBy [#col2 & Asc])))
346−SELECT "col1" AS "col1", rank() OVER (PARTITION BY "col1" ORDER BY "col2" ASC) AS "col2" FROM "tab" AS "tab"
348−correlated subqueries
352− query :: Query_ (Public Schema) () (Only Int32)
354− select (#col1 `as` #fromOnly) (from (table (#tab `as` #t1))
270+ selectStar (from (table #tab))
355− & where_ (exists (
271+ `unionAll`
356− select Star (from (table (#tab `as` #t2))
272+ selectStar (from (table #tab))
357− & where_ (#t2 ! #col2 .== #t1 ! #col1)))))
273+in renderQuery query
360−SELECT "col1" AS "fromOnly" FROM "tab" AS "t1" WHERE EXISTS (SELECT * FROM "tab" AS "t2" WHERE ("t2"."col2" = "t1"."col1"))
275+"(SELECT * FROM \"tab\" AS \"tab\") UNION ALL (SELECT * FROM \"tab\" AS \"tab\")"
363−type family Query_
277+newtype Query
364− (schemas :: SchemasType)
278+ (schema :: SchemaType)
365− (parameters :: Type)
279+ (params :: [NullityType])
366− (row :: Type) where
280+ (columns :: RelationType)
367− Query_ schemas params row =
281+ = UnsafeQuery { renderQuery :: ByteString }
368− Query '[] '[] schemas (TuplePG params) (RowPG row)
282+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
370-- | The results of two queries can be combined using the set operation
284-- | The results of two queries can be combined using the set operation
371-- `union`. Duplicate rows are eliminated.
285-- `union`. Duplicate rows are eliminated.
373− :: Query outer commons schemas params columns
287+ :: Query schema params columns
374− -> Query outer commons schemas params columns
288+ -> Query schema params columns
375− -> Query outer commons schemas params columns
289+ -> Query schema params columns
376q1 `union` q2 = UnsafeQuery $
290q1 `union` q2 = UnsafeQuery $
377− parenthesized (renderSQL q1)
291+ parenthesized (renderQuery q1)
378 <+> "UNION"
292 <+> "UNION"
379− <+> parenthesized (renderSQL q2)
293+ <+> parenthesized (renderQuery q2)
381-- | The results of two queries can be combined using the set operation
295-- | The results of two queries can be combined using the set operation
382-- `unionAll`, the disjoint union. Duplicate rows are retained.
296-- `unionAll`, the disjoint union. Duplicate rows are retained.
384− :: Query outer commons schemas params columns
298+ :: Query schema params columns
385− -> Query outer commons schemas params columns
299+ -> Query schema params columns
386− -> Query outer commons schemas params columns
300+ -> Query schema params columns
387q1 `unionAll` q2 = UnsafeQuery $
301q1 `unionAll` q2 = UnsafeQuery $
388− parenthesized (renderSQL q1)
302+ parenthesized (renderQuery q1)
389 <+> "UNION" <+> "ALL"
303 <+> "UNION" <+> "ALL"
390− <+> parenthesized (renderSQL q2)
304+ <+> parenthesized (renderQuery q2)
392-- | The results of two queries can be combined using the set operation
306-- | The results of two queries can be combined using the set operation
393-- `intersect`, the intersection. Duplicate rows are eliminated.
307-- `intersect`, the intersection. Duplicate rows are eliminated.
395− :: Query outer commons schemas params columns
309+ :: Query schema params columns
396− -> Query outer commons schemas params columns
310+ -> Query schema params columns
397− -> Query outer commons schemas params columns
311+ -> Query schema params columns
398q1 `intersect` q2 = UnsafeQuery $
312q1 `intersect` q2 = UnsafeQuery $
399− parenthesized (renderSQL q1)
313+ parenthesized (renderQuery q1)
400 <+> "INTERSECT"
314 <+> "INTERSECT"
401− <+> parenthesized (renderSQL q2)
315+ <+> parenthesized (renderQuery q2)
403-- | The results of two queries can be combined using the set operation
317-- | The results of two queries can be combined using the set operation
404-- `intersectAll`, the intersection. Duplicate rows are retained.
318-- `intersectAll`, the intersection. Duplicate rows are retained.
405intersectAll
319intersectAll
406− :: Query outer commons schemas params columns
320+ :: Query schema params columns
407− -> Query outer commons schemas params columns
321+ -> Query schema params columns
408− -> Query outer commons schemas params columns
322+ -> Query schema params columns
409q1 `intersectAll` q2 = UnsafeQuery $
323q1 `intersectAll` q2 = UnsafeQuery $
410− parenthesized (renderSQL q1)
324+ parenthesized (renderQuery q1)
411 <+> "INTERSECT" <+> "ALL"
325 <+> "INTERSECT" <+> "ALL"
412− <+> parenthesized (renderSQL q2)
326+ <+> parenthesized (renderQuery q2)
414-- | The results of two queries can be combined using the set operation
328-- | The results of two queries can be combined using the set operation
415-- `except`, the set difference. Duplicate rows are eliminated.
329-- `except`, the set difference. Duplicate rows are eliminated.
417− :: Query outer commons schemas params columns
331+ :: Query schema params columns
418− -> Query outer commons schemas params columns
332+ -> Query schema params columns
419− -> Query outer commons schemas params columns
333+ -> Query schema params columns
420q1 `except` q2 = UnsafeQuery $
334q1 `except` q2 = UnsafeQuery $
421− parenthesized (renderSQL q1)
335+ parenthesized (renderQuery q1)
422 <+> "EXCEPT"
336 <+> "EXCEPT"
423− <+> parenthesized (renderSQL q2)
337+ <+> parenthesized (renderQuery q2)
425-- | The results of two queries can be combined using the set operation
339-- | The results of two queries can be combined using the set operation
426-- `exceptAll`, the set difference. Duplicate rows are retained.
340-- `exceptAll`, the set difference. Duplicate rows are retained.
428− :: Query outer commons schemas params columns
342+ :: Query schema params columns
429− -> Query outer commons schemas params columns
343+ -> Query schema params columns
430− -> Query outer commons schemas params columns
344+ -> Query schema params columns
431q1 `exceptAll` q2 = UnsafeQuery $
345q1 `exceptAll` q2 = UnsafeQuery $
432− parenthesized (renderSQL q1)
346+ parenthesized (renderQuery q1)
433 <+> "EXCEPT" <+> "ALL"
347 <+> "EXCEPT" <+> "ALL"
434− <+> parenthesized (renderSQL q2)
348+ <+> parenthesized (renderQuery q2)
436{-----------------------------------------
350{-----------------------------------------
437SELECT queries
351SELECT queries
438-----------------------------------------}
352-----------------------------------------}
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`.
446−data Selection outer commons grp schemas params from row where
448− :: HasUnique tab from row
449− => Selection outer commons 'Ungrouped schemas params from row
450− -- ^ `HasUnique` table in the `FromClause`
454− -- ^ `Has` table with `Alias`
455− -> Selection outer commons 'Ungrouped schemas params from 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
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
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
474−instance (KnownSymbol col, row ~ '[col ::: ty])
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
484− ( Has tab (Join outer from) row0
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])
493− (Selection outer commons 'Ungrouped schemas params from row1) where
494− fromLabel = fromLabel @col `as` Alias
496− ( HasUnique tab (Join outer from) row0
498− , row1 ~ '[col ::: ty]
499− , GroupedBy tab col bys )
501− (Selection outer commons ('Grouped bys) schemas params from row1) where
502− fromLabel = fromLabel @col `as` Alias
504−instance RenderSQL (Selection outer commons grp schemas params from row) where
506− List list -> renderCommaSeparated (renderAliased renderSQL) list
508− DotStar tab -> renderSQL tab <> ".*"
509− Also right left -> renderSQL left <> ", " <> renderSQL right
510− Over winFns winDef ->
513− :: Aliased (WindowFunction outer commons grp schemas params from) field
515− renderOver (winFn `As` col) = renderSQL winFn
516− <+> "OVER" <+> parenthesized (renderSQL winDef)
517− <+> "AS" <+> renderSQL col
519− renderCommaSeparated renderOver winFns
522− (Selection outer commons grp schemas params from '["fromOnly" ::: 'NotNull 'PGtext]) where
523− fromString str = fromString str `as` Alias
525-- | the `TableExpression` in the `select` command constructs an intermediate
354-- | the `TableExpression` in the `select` command constructs an intermediate
526-- virtual table by possibly combining tables, views, eliminating rows,
355-- virtual table by possibly combining tables, views, eliminating rows,
527-- grouping, etc. This table is finally passed on to processing by
356-- grouping, etc. This table is finally passed on to processing by
528−-- the select list. The `Selection` determines which columns of
357+-- the select list. The select list determines which columns of
529-- the intermediate table are actually output.
358-- the intermediate table are actually output.
531− :: (SListI row, row ~ (x ': xs))
360+ :: SListI columns
532− => Selection outer commons grp schemas params from row
361+ => NP (Aliased (Expression relations grouping params)) (column ': columns)
534− -> TableExpression outer commons grp schemas params from
535− -- ^ intermediate virtual table
536− -> Query outer commons schemas params row
537−select selection tabexpr = UnsafeQuery $
539− <+> renderSQL selection
540− <+> renderSQL tabexpr
542−-- | Like `select` but takes an `NP` list of `Expression`s instead
543−-- of a general `Selection`.
545− :: (SListI row, row ~ (x ': xs))
546− => NP (Aliased (Expression outer commons grp schemas params from)) row
547 -- ^ select list
362 -- ^ select list
548− -> TableExpression outer commons grp schemas params from
363+ -> TableExpression schema params relations grouping
549 -- ^ intermediate virtual table
364 -- ^ intermediate virtual table
550− -> Query outer commons schemas params row
365+ -> Query schema params (column ': columns)
551−select_ = select . List
366+select list rels = UnsafeQuery $
368+ <+> renderCommaSeparated (renderAliasedAs renderExpression) list
369+ <+> renderTableExpression rels
553-- | After the select list has been processed, the result table can
371-- | After the select list has been processed, the result table can
554-- be subject to the elimination of duplicate rows using `selectDistinct`.
372-- be subject to the elimination of duplicate rows using `selectDistinct`.
555selectDistinct
373selectDistinct
556− :: (SListI columns, columns ~ (col ': cols))
374+ :: SListI columns
557− => Selection outer commons grp schemas params from columns
375+ => NP (Aliased (Expression relations 'Ungrouped params)) (column ': columns)
558− -- ^ selection
376+ -- ^ select list
559− -> TableExpression outer commons grp schemas params from
377+ -> TableExpression schema params relations 'Ungrouped
560 -- ^ intermediate virtual table
378 -- ^ intermediate virtual table
561− -> Query outer commons schemas params columns
379+ -> Query schema params (column ': columns)
562−selectDistinct selection tabexpr = UnsafeQuery $
380+selectDistinct list rels = UnsafeQuery $
563 "SELECT DISTINCT"
381 "SELECT DISTINCT"
564− <+> renderSQL selection
382+ <+> renderCommaSeparated (renderAliasedAs renderExpression) list
565− <+> renderSQL tabexpr
383+ <+> renderTableExpression rels
567−-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead
385+-- | The simplest kind of query is `selectStar` which emits all columns
568−-- of a general `Selection`.
386+-- that the table expression produces.
569−selectDistinct_
387+selectStar
570− :: (SListI columns, columns ~ (col ': cols))
388+ :: HasUnique relation relations columns
571− => NP (Aliased (Expression outer commons grp schemas params from)) columns
389+ => TableExpression schema params relations 'Ungrouped
573− -> TableExpression outer commons grp schemas params from
574 -- ^ intermediate virtual table
390 -- ^ intermediate virtual table
575− -> Query outer commons schemas params columns
391+ -> Query schema params columns
576−selectDistinct_ = selectDistinct . List
392+selectStar rels = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression rels
578−{-|
394+-- | A `selectDistinctStar` emits all columns that the table expression
579−`selectDistinctOn` keeps only the first row of each set of rows where
395+-- produces and eliminates duplicate rows.
580−the given expressions evaluate to equal. The DISTINCT ON expressions are
396+selectDistinctStar
581−interpreted using the same rules as for ORDER BY. ORDER BY is used to
397+ :: HasUnique relation relations columns
582−ensure that the desired row appears first.
398+ => TableExpression schema params relations 'Ungrouped
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.
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.
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
597− -> TableExpression outer commons grp schemas params from
598 -- ^ intermediate virtual table
399 -- ^ intermediate virtual table
599− -> Query outer commons schemas params columns
400+ -> Query schema params columns
600−selectDistinctOn distincts selection tab = UnsafeQuery $
401+selectDistinctStar rels = UnsafeQuery $
601− "SELECT DISTINCT ON"
402+ "SELECT DISTINCT" <+> "*" <+> renderTableExpression rels
602− <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))
403+
603− <+> renderSQL selection
404+-- | When working with multiple tables, it can also be useful to ask
604− <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})
405+-- for all the columns of a particular table, using `selectDotStar`.
605− where
406+selectDotStar
606− renderDistinctOn = \case
407+ :: Has relation relations columns
607− Asc expression -> renderSQL expression
408+ => Alias relation
608− Desc expression -> renderSQL expression
409+ -- ^ particular virtual subtable
609− AscNullsFirst expression -> renderSQL expression
410+ -> TableExpression schema params relations 'Ungrouped
610− DescNullsFirst expression -> renderSQL expression
411+ -- ^ intermediate virtual table
611− AscNullsLast expression -> renderSQL expression
412+ -> Query schema params columns
612− DescNullsLast expression -> renderSQL expression
413+selectDotStar rel relations = UnsafeQuery $
613−
414+ "SELECT" <+> renderAlias rel <> ".*" <+> renderTableExpression relations
614−-- | Like `selectDistinctOn` but takes an `NP` list of `Expression`s instead
415+
615−-- of a general `Selection`.
416+-- | A `selectDistinctDotStar` asks for all the columns of a particular table,
616−selectDistinctOn_
417+-- and eliminates duplicate rows.
617− :: (SListI columns, columns ~ (col ': cols))
418+selectDistinctDotStar
618− => [SortExpression outer commons grp schemas params from]
419+ :: Has relation relations columns
619− -- ^ distinct on and return the first row in ordering
420+ => Alias relation
620− -> NP (Aliased (Expression outer commons grp schemas params from)) columns
421+ -- ^ particular virtual table
621− -- ^ selection
422+ -> TableExpression schema params relations 'Ungrouped
622− -> TableExpression outer commons grp schemas params from
623 -- ^ intermediate virtual table
423 -- ^ intermediate virtual table
624− -> Query outer commons schemas params columns
424+ -> Query schema params columns
625−selectDistinctOn_ distincts = selectDistinctOn distincts . List
425+selectDistinctDotStar rel relations = UnsafeQuery $
626−
426+ "SELECT DISTINCT" <+> renderAlias rel <> ".*"
627−-- | `values` computes a row value or set of row values
427+ <+> renderTableExpression relations
628−-- specified by value expressions. It is most commonly used
428+
629−-- to generate a “constant table” within a larger command,
630−-- but it can be used on its own.
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")
637 :: SListI cols
430 :: SListI cols
638− => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols
431+ => NP (Aliased (Expression '[] 'Ungrouped params)) cols
639− -> [NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols]
432+ -> [NP (Aliased (Expression '[] 'Ungrouped params)) cols]
640− -- ^ When more than one row is specified, all the rows must
433+ -> Query schema params cols
641− -- must have the same number of elements
642− -> Query outer commons schemas params cols
643values rw rws = UnsafeQuery $ "SELECT * FROM"
434values rw rws = UnsafeQuery $ "SELECT * FROM"
644 <+> parenthesized (
435 <+> parenthesized (
@@ -650,18 +441,9 @@ values rw rws = UnsafeQuery $ "SELECT * FROM"
650 <+> parenthesized (renderCommaSeparated renderAliasPart rw)
441 <+> parenthesized (renderCommaSeparated renderAliasPart rw)
652 renderAliasPart, renderValuePart
443 renderAliasPart, renderValuePart
653− :: Aliased (Expression outer commons 'Ungrouped schemas params '[] ) ty -> ByteString
444+ :: Aliased (Expression '[] 'Ungrouped params) ty -> ByteString
654− renderAliasPart (_ `As` name) = renderSQL name
445+ renderAliasPart (_ `As` name) = renderAlias name
655− renderValuePart (value `As` _) = renderSQL value
446+ renderValuePart (value `As` _) = renderExpression value
657−-- | `values_` computes a row value or set of row values
658−-- specified by value expressions.
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 []
666{-----------------------------------------
448{-----------------------------------------
667Table Expressions
449Table Expressions
@@ -674,17 +456,15 @@ Table Expressions
674-- to a table on disk, a so-called base table, but more complex expressions
456-- 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.
457-- can be used to modify or combine base tables in various ways.
676data TableExpression
458data TableExpression
677− (outer :: FromType)
459+ (schema :: SchemaType)
678− (commons :: FromType)
680− (schemas :: SchemasType)
681 (params :: [NullityType])
460 (params :: [NullityType])
682− (from :: FromType)
461+ (relations :: RelationsType)
462+ (grouping :: Grouping)
683 = TableExpression
463 = TableExpression
684− { fromClause :: FromClause outer commons schemas params from
464+ { fromClause :: FromClause schema params relations
685 -- ^ A table reference that can be a table name, or a derived table such
465 -- ^ 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.
466 -- as a subquery, a @JOIN@ construct, or complex combinations of these.
687− , whereClause :: [Condition outer commons 'Ungrouped schemas params from]
467+ , whereClause :: [Condition relations 'Ungrouped params]
688 -- ^ optional search coditions, combined with `.&&`. After the processing
468 -- ^ optional search coditions, combined with `.&&`. After the processing
689 -- of the `fromClause` is done, each row of the derived virtual table
469 -- of the `fromClause` is done, each row of the derived virtual table
690 -- is checked against the search condition. If the result of the
470 -- is checked against the search condition. If the result of the
@@ -693,20 +473,20 @@ data TableExpression
693 -- at least one column of the table generated in the `fromClause`;
473 -- at least one column of the table generated in the `fromClause`;
694 -- this is not required, but otherwise the WHERE clause will
474 -- this is not required, but otherwise the WHERE clause will
695 -- be fairly useless.
475 -- be fairly useless.
696− , groupByClause :: GroupByClause grp from
476+ , groupByClause :: GroupByClause relations grouping
697 -- ^ The `groupByClause` is used to group together those rows in a table
477 -- ^ 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
478 -- 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
479 -- 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
480 -- 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
481 -- rows in the group. This is done to eliminate redundancy in the output
702 -- and/or compute aggregates that apply to these groups.
482 -- and/or compute aggregates that apply to these groups.
703− , havingClause :: HavingClause outer commons grp schemas params from
483+ , havingClause :: HavingClause relations grouping params
704 -- ^ If a table has been grouped using `groupBy`, but only certain groups
484 -- ^ If a table has been grouped using `groupBy`, but only certain groups
705 -- are of interest, the `havingClause` can be used, much like a
485 -- are of interest, the `havingClause` can be used, much like a
706 -- `whereClause`, to eliminate groups from the result. Expressions in the
486 -- `whereClause`, to eliminate groups from the result. Expressions in the
707 -- `havingClause` can refer both to grouped expressions and to ungrouped
487 -- `havingClause` can refer both to grouped expressions and to ungrouped
708 -- expressions (which necessarily involve an aggregate function).
488 -- expressions (which necessarily involve an aggregate function).
709− , orderByClause :: [SortExpression outer commons grp schemas params from]
489+ , orderByClause :: [SortExpression relations grouping params]
710 -- ^ The `orderByClause` is for optional sorting. When more than one
490 -- ^ The `orderByClause` is for optional sorting. When more than one
711 -- `SortExpression` is specified, the later (right) values are used to sort
491 -- `SortExpression` is specified, the later (right) values are used to sort
712 -- rows that are equal according to the earlier (left) values.
492 -- rows that are equal according to the earlier (left) values.
@@ -716,69 +496,72 @@ data TableExpression
716 -- will be returned (but possibly fewer, if the query itself yields
496 -- will be returned (but possibly fewer, if the query itself yields
717 -- fewer rows).
497 -- fewer rows).
718 , offsetClause :: [Word64]
498 , offsetClause :: [Word64]
719− -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count
499+ -- ^ The `offsetClause` is combined with `+` to give an offset count
720 -- if nonempty. The offset count says to skip that many rows before
500 -- 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
501 -- beginning to return rows. The rows are skipped before the limit count
722 -- is applied.
502 -- is applied.
723− } deriving (GHC.Generic)
503+ }
725-- | Render a `TableExpression`
505-- | Render a `TableExpression`
726−instance RenderSQL (TableExpression outer commons grp schemas params from) where
506+renderTableExpression
727− renderSQL
507+ :: TableExpression schema params relations grouping
728− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat
508+ -> ByteString
729− [ "FROM ", renderSQL frm'
509+renderTableExpression
730− , renderWheres whs'
510+ (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat
731− , renderSQL grps'
511+ [ "FROM ", renderFromClause frm'
732− , renderSQL hvs'
512+ , renderWheres whs'
733− , renderOrderByClause srts'
513+ , renderGroupByClause grps'
734− , renderLimits lims'
514+ , renderHavingClause hvs'
735− , renderOffsets offs' ]
515+ , renderOrderByClause srts'
736− where
516+ , renderLimits lims'
737− renderWheres = \case
517+ , renderOffsets offs'
739− wh:[] -> " WHERE" <+> renderSQL wh
519+ where
740− wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)
520+ renderWheres = \case
741− renderOrderByClause = \case
521+ [] -> ""
742− [] -> ""
522+ wh:[] -> " WHERE" <+> renderExpression wh
743− srts -> " ORDER BY"
523+ wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)
744− <+> commaSeparated (renderSQL <$> srts)
524+ renderOrderByClause = \case
745− renderLimits = \case
525+ [] -> ""
746− [] -> ""
526+ srts -> " ORDER BY"
747− lims -> " LIMIT" <+> fromString (show (minimum lims))
527+ <+> commaSeparated (renderSortExpression <$> srts)
748− renderOffsets = \case
528+ renderLimits = \case
749− [] -> ""
529+ [] -> ""
750− offs -> " OFFSET" <+> fromString (show (sum offs))
530+ lims -> " LIMIT" <+> fromString (show (minimum lims))
531+ renderOffsets = \case
533+ offs -> " OFFSET" <+> fromString (show (sum offs))
752-- | A `from` generates a `TableExpression` from a table reference that can be
535-- | 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,
536-- 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_`,
537-- or complex combinations of these. A `from` may be transformed by `where_`,
755−-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
538+-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
756-- to match the left-to-right sequencing of their placement in SQL.
539-- to match the left-to-right sequencing of their placement in SQL.
758− :: FromClause outer commons schemas params from -- ^ table reference
541+ :: FromClause schema params relations -- ^ table reference
759− -> TableExpression outer commons 'Ungrouped schemas params from
542+ -> TableExpression schema params relations 'Ungrouped
760−from tab = TableExpression tab [] noGroups NoHaving [] [] []
543+from rels = TableExpression rels [] NoGroups NoHaving [] [] []
762-- | A `where_` is an endomorphism of `TableExpression`s which adds a
545-- | A `where_` is an endomorphism of `TableExpression`s which adds a
763-- search condition to the `whereClause`.
546-- search condition to the `whereClause`.
765− :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition
548+ :: Condition relations 'Ungrouped params -- ^ filtering condition
766− -> TableExpression outer commons grp schemas params from
549+ -> TableExpression schema params relations grouping
767− -> TableExpression outer commons grp schemas params from
550+ -> TableExpression schema params relations grouping
768where_ wh rels = rels {whereClause = wh : whereClause rels}
551where_ wh rels = rels {whereClause = wh : whereClause rels}
770−-- | A `groupBy` is a transformation of `TableExpression`s which switches
553+-- | A `group` is a transformation of `TableExpression`s which switches
771−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform
554+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform
772-- a "grand total" aggregation query.
555-- a "grand total" aggregation query.
774 :: SListI bys
557 :: SListI bys
775− => NP (By from) bys -- ^ grouped columns
558+ => NP (By relations) bys -- ^ grouped columns
776− -> TableExpression outer commons 'Ungrouped schemas params from
559+ -> TableExpression schema params relations 'Ungrouped
777− -> TableExpression outer commons ('Grouped bys) schemas params from
560+ -> TableExpression schema params relations ('Grouped bys)
778−groupBy bys rels = TableExpression
561+group bys rels = TableExpression
779 { fromClause = fromClause rels
562 { fromClause = fromClause rels
780 , whereClause = whereClause rels
563 , whereClause = whereClause rels
781− , groupByClause = group bys
564+ , groupByClause = Group bys
782 , havingClause = Having []
565 , havingClause = Having []
783 , orderByClause = []
566 , orderByClause = []
784 , limitClause = limitClause rels
567 , limitClause = limitClause rels
@@ -788,29 +571,34 @@ groupBy bys rels = TableExpression
788-- | A `having` is an endomorphism of `TableExpression`s which adds a
571-- | A `having` is an endomorphism of `TableExpression`s which adds a
789-- search condition to the `havingClause`.
572-- search condition to the `havingClause`.
791− :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition
574+ :: Condition relations ('Grouped bys) params -- ^ having condition
792− -> TableExpression outer commons ('Grouped bys) schemas params from
575+ -> TableExpression schema params relations ('Grouped bys)
793− -> TableExpression outer commons ('Grouped bys) schemas params from
576+ -> TableExpression schema params relations ('Grouped bys)
794having hv rels = rels
577having hv rels = rels
795 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }
578 { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }
797−instance OrderBy TableExpression where
580+-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an
798− orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}
581+-- ordering to the right of the `orderByClause`.
583+ :: [SortExpression relations grouping params] -- ^ sort expressions
584+ -> TableExpression schema params relations grouping
585+ -> TableExpression schema params relations grouping
586+orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}
800-- | A `limit` is an endomorphism of `TableExpression`s which adds to the
588-- | A `limit` is an endomorphism of `TableExpression`s which adds to the
801-- `limitClause`.
589-- `limitClause`.
803 :: Word64 -- ^ limit parameter
591 :: Word64 -- ^ limit parameter
804− -> TableExpression outer commons grp schemas params from
592+ -> TableExpression schema params relations grouping
805− -> TableExpression outer commons grp schemas params from
593+ -> TableExpression schema params relations grouping
806limit lim rels = rels {limitClause = lim : limitClause rels}
594limit lim rels = rels {limitClause = lim : limitClause rels}
808-- | An `offset` is an endomorphism of `TableExpression`s which adds to the
596-- | An `offset` is an endomorphism of `TableExpression`s which adds to the
809-- `offsetClause`.
597-- `offsetClause`.
811 :: Word64 -- ^ offset parameter
599 :: Word64 -- ^ offset parameter
812− -> TableExpression outer commons grp schemas params from
600+ -> TableExpression schema params relations grouping
813− -> TableExpression outer commons grp schemas params from
601+ -> TableExpression schema params relations grouping
814offset off rels = rels {offsetClause = off : offsetClause rels}
602offset off rels = rels {offsetClause = off : offsetClause rels}
816{-----------------------------------------
604{-----------------------------------------
@@ -821,76 +609,61 @@ FROM clauses
821A `FromClause` can be a table name, or a derived table such
609A `FromClause` can be a table name, or a derived table such
822as a subquery, a @JOIN@ construct, or complex combinations of these.
610as a subquery, a @JOIN@ construct, or complex combinations of these.
824−newtype FromClause outer commons schemas params from
612+newtype FromClause schema params relations
825 = UnsafeFromClause { renderFromClause :: ByteString }
613 = UnsafeFromClause { renderFromClause :: ByteString }
826 deriving (GHC.Generic,Show,Eq,Ord,NFData)
614 deriving (GHC.Generic,Show,Eq,Ord,NFData)
827−instance RenderSQL (FromClause outer commons schemas params from) where
828− renderSQL = renderFromClause
830−-- | A real `table` is a table from the database.
616+-- | A real `table` is a table from the schema.
832− :: (Has sch schemas schema, Has tab schema ('Table table))
618+ :: Has tab schema ('Table table)
833− => Aliased (QualifiedAlias sch) (alias ::: tab)
619+ => Aliased Alias (alias ::: tab)
834− -> FromClause outer commons schemas params '[alias ::: TableToRow table]
620+ -> FromClause schema params '[alias ::: TableToRelation table]
835table (tab `As` alias) = UnsafeFromClause $
621table (tab `As` alias) = UnsafeFromClause $
836− renderSQL tab <+> "AS" <+> renderSQL alias
622+ renderAlias tab <+> "AS" <+> renderAlias alias
838-- | `subquery` derives a table from a `Query`.
624-- | `subquery` derives a table from a `Query`.
840− :: Aliased (Query outer commons schemas params) query
626+ :: Aliased (Query schema params) rel
841− -> FromClause outer commons schemas params '[query]
627+ -> FromClause schema params '[rel]
842−subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)
628+subquery = UnsafeFromClause . renderAliasedAs (parenthesized . renderQuery)
844-- | `view` derives a table from a `View`.
630-- | `view` derives a table from a `View`.
846− :: (Has sch schemas schema, Has vw schema ('View view))
632+ :: Has view schema ('View rel)
847− => Aliased (QualifiedAlias sch) (alias ::: vw)
633+ => Aliased Alias (alias ::: view)
848− -> FromClause outer commons schemas params '[alias ::: view]
634+ -> FromClause schema params '[alias ::: rel]
849view (vw `As` alias) = UnsafeFromClause $
635view (vw `As` alias) = UnsafeFromClause $
850− renderSQL vw <+> "AS" <+> renderSQL alias
636+ renderAlias vw <+> "AS" <+> renderAlias alias
852−-- | `common` derives a table from a common table expression.
638+{- | @left & crossJoin right@. For every possible combination of rows from
853−common
639+ @left@ and @right@ (i.e., a Cartesian product), the joined table will contain
854− :: Has cte commons common
640+ a row consisting of all columns in @left@ followed by all columns in @right@.
855− => Aliased Alias (alias ::: cte)
641+ If the tables have @n@ and @m@ rows respectively, the joined table will
856− -> FromClause outer commons schemas params '[alias ::: common]
642+ have @n * m@ rows.
857−common (cte `As` alias) = UnsafeFromClause $
858− renderSQL cte <+> "AS" <+> renderSQL alias
860−instance Additional (FromClause outer commons schemas params) where
861− also right left = UnsafeFromClause $
862− renderSQL left <> ", " <> renderSQL right
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
872− :: FromClause outer commons schemas params right
645+ :: FromClause schema params right
873 -- ^ right
646 -- ^ right
874− -> FromClause outer commons schemas params left
647+ -> FromClause schema params left
875 -- ^ left
648 -- ^ left
876− -> FromClause outer commons schemas params (Join left right)
649+ -> FromClause schema params (Join left right)
877crossJoin right left = UnsafeFromClause $
650crossJoin right left = UnsafeFromClause $
878− renderSQL left <+> "CROSS JOIN" <+> renderSQL right
651+ renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right
880{- | @left & innerJoin right on@. The joined table is filtered by
653{- | @left & innerJoin right on@. The joined table is filtered by
881the @on@ condition.
654the @on@ condition.
884− :: FromClause outer commons schemas params right
657+ :: FromClause schema params right
885 -- ^ right
658 -- ^ right
886− -> Condition outer commons 'Ungrouped schemas params (Join left right)
659+ -> Condition (Join left right) 'Ungrouped params
887 -- ^ @on@ condition
660 -- ^ @on@ condition
888− -> FromClause outer commons schemas params left
661+ -> FromClause schema params left
889 -- ^ left
662 -- ^ left
890− -> FromClause outer commons schemas params (Join left right)
663+ -> FromClause schema params (Join left right)
891innerJoin right on left = UnsafeFromClause $
664innerJoin right on left = UnsafeFromClause $
892− renderSQL left <+> "INNER JOIN" <+> renderSQL right
665+ renderFromClause left <+> "INNER JOIN" <+> renderFromClause right
893− <+> "ON" <+> renderSQL on
666+ <+> "ON" <+> renderExpression on
895{- | @left & leftOuterJoin right on@. First, an inner join is performed.
668{- | @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
669 Then, for each row in @left@ that does not satisfy the @on@ condition with
@@ -898,16 +671,16 @@ innerJoin right on left = UnsafeFromClause $
898 Thus, the joined table always has at least one row for each row in @left@.
671 Thus, the joined table always has at least one row for each row in @left@.
900leftOuterJoin
673leftOuterJoin
901− :: FromClause outer commons schemas params right
674+ :: FromClause schema params right
902 -- ^ right
675 -- ^ right
903− -> Condition outer commons 'Ungrouped schemas params (Join left right)
676+ -> Condition (Join left right) 'Ungrouped params
904 -- ^ @on@ condition
677 -- ^ @on@ condition
905− -> FromClause outer commons schemas params left
678+ -> FromClause schema params left
906 -- ^ left
679 -- ^ left
907− -> FromClause outer commons schemas params (Join left (NullifyFrom right))
680+ -> FromClause schema params (Join left (NullifyRelations right))
908leftOuterJoin right on left = UnsafeFromClause $
681leftOuterJoin right on left = UnsafeFromClause $
909− renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right
682+ renderFromClause left <+> "LEFT OUTER JOIN" <+> renderFromClause right
910− <+> "ON" <+> renderSQL on
683+ <+> "ON" <+> renderExpression on
912{- | @left & rightOuterJoin right on@. First, an inner join is performed.
685{- | @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
686 Then, for each row in @right@ that does not satisfy the @on@ condition with
@@ -916,16 +689,16 @@ leftOuterJoin right on left = UnsafeFromClause $
916 have a row for each row in @right@.
689 have a row for each row in @right@.
918rightOuterJoin
691rightOuterJoin
919− :: FromClause outer commons schemas params right
692+ :: FromClause schema params right
920 -- ^ right
693 -- ^ right
921− -> Condition outer commons 'Ungrouped schemas params (Join left right)
694+ -> Condition (Join left right) 'Ungrouped params
922 -- ^ @on@ condition
695 -- ^ @on@ condition
923− -> FromClause outer commons schemas params left
696+ -> FromClause schema params left
924 -- ^ left
697 -- ^ left
925− -> FromClause outer commons schemas params (Join (NullifyFrom left) right)
698+ -> FromClause schema params (Join (NullifyRelations left) right)
926rightOuterJoin right on left = UnsafeFromClause $
699rightOuterJoin right on left = UnsafeFromClause $
927− renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right
700+ renderFromClause left <+> "RIGHT OUTER JOIN" <+> renderFromClause right
928− <+> "ON" <+> renderSQL on
701+ <+> "ON" <+> renderExpression on
930{- | @left & fullOuterJoin right on@. First, an inner join is performed.
703{- | @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
704 Then, for each row in @left@ that does not satisfy the @on@ condition with
@@ -935,56 +708,47 @@ rightOuterJoin right on left = UnsafeFromClause $
935 is added.
708 is added.
937fullOuterJoin
710fullOuterJoin
938− :: FromClause outer commons schemas params right
711+ :: FromClause schema params right
939 -- ^ right
712 -- ^ right
940− -> Condition outer commons 'Ungrouped schemas params (Join left right)
713+ -> Condition (Join left right) 'Ungrouped params
941 -- ^ @on@ condition
714 -- ^ @on@ condition
942− -> FromClause outer commons schemas params left
715+ -> FromClause schema params left
943 -- ^ left
716 -- ^ left
944− -> FromClause outer commons schemas params
717+ -> FromClause schema params
945− (Join (NullifyFrom left) (NullifyFrom right))
718+ (Join (NullifyRelations left) (NullifyRelations right))
946fullOuterJoin right on left = UnsafeFromClause $
719fullOuterJoin right on left = UnsafeFromClause $
947− renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right
720+ renderFromClause left <+> "FULL OUTER JOIN" <+> renderFromClause right
948− <+> "ON" <+> renderSQL on
721+ <+> "ON" <+> renderExpression on
950{-----------------------------------------
723{-----------------------------------------
952-----------------------------------------}
725-----------------------------------------}
954−-- | `By`s are used in `groupBy` to reference a list of columns which are then
727+-- | `By`s are used in `group` to reference a list of columns which are then
955-- used to group together those rows in a table that have the same values
728-- 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
729-- in all the columns listed. @By \#col@ will reference an unambiguous
957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
730-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
958-- qualified column @tab.col@.
731-- qualified column @tab.col@.
960− (from :: FromType)
733+ (relations :: RelationsType)
961 (by :: (Symbol,Symbol)) where
734 (by :: (Symbol,Symbol)) where
963− :: (HasUnique table from columns, Has column columns ty)
736+ :: (HasUnique relation relations columns, Has column columns ty)
964 => Alias column
737 => Alias column
965− -> By from '(table, column)
738+ -> By relations '(relation, column)
967− :: (Has table from columns, Has column columns ty)
740+ :: (Has relation relations columns, Has column columns ty)
968− => Alias table
741+ => (Alias relation, Alias column)
969− -> Alias column
742+ -> By relations '(relation, column)
970− -> By from '(table, column)
743+deriving instance Show (By relations by)
971−deriving instance Show (By from by)
744+deriving instance Eq (By relations by)
972−deriving instance Eq (By from by)
745+deriving instance Ord (By relations by)
973−deriving instance Ord (By from by)
746+
974−instance RenderSQL (By from by) where
747+-- | Renders a `By`.
975− renderSQL = \case
748+renderBy :: By relations by -> ByteString
976− By1 column -> renderSQL column
749+renderBy = \case
977− By2 rel column -> renderSQL rel <> "." <> renderSQL column
750+ By column -> renderAlias column
978−
751+ By2 (rel, column) -> renderAlias rel <> "." <> renderAlias column
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
989-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.
753-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.
990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
754-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
@@ -992,107 +756,82 @@ instance (Has rel rels cols, Has col cols ty, bys ~ '[ '(rel, col)])
992-- done on @NoGroups@ while all output `Expression`s must be aggregated
756-- done on @NoGroups@ while all output `Expression`s must be aggregated
993-- in @Group Nil@. In general, all output `Expression`s in the
757-- in @Group Nil@. In general, all output `Expression`s in the
994-- complement of @bys@ must be aggregated in @Group bys@.
758-- complement of @bys@ must be aggregated in @Group bys@.
995−newtype GroupByClause grp from = UnsafeGroupByClause
759+data GroupByClause relations grouping where
996− { renderGroupByClause :: ByteString }
760+ NoGroups :: GroupByClause relations 'Ungrouped
997− deriving (GHC.Generic,Show,Eq,Ord,NFData)
761+ Group
998−instance RenderSQL (GroupByClause grp from) where
762+ :: SListI bys
999− renderSQL = renderGroupByClause
763+ => NP (By relations) bys
1000−noGroups :: GroupByClause 'Ungrouped from
764+ -> GroupByClause relations ('Grouped bys)
1001−noGroups = UnsafeGroupByClause ""
765+
1002−group
766+-- | Renders a `GroupByClause`.
1003− :: SListI bys
767+renderGroupByClause :: GroupByClause relations grouping -> ByteString
1004− => NP (By from) bys
768+renderGroupByClause = \case
1005− -> GroupByClause ('Grouped bys) from
769+ NoGroups -> ""
1006−group bys = UnsafeGroupByClause $ case bys of
770+ Group Nil -> ""
1007− Nil -> ""
771+ Group bys -> " GROUP BY" <+> renderCommaSeparated renderBy bys
1008− bys' -> " GROUP BY" <+> renderCommaSeparated renderSQL bys'
1010-- | A `HavingClause` is used to eliminate groups that are not of interest.
773-- | A `HavingClause` is used to eliminate groups that are not of interest.
1011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
774-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
1012-- `TableExpression` must use `Having` whose conditions are combined with
775-- `TableExpression` must use `Having` whose conditions are combined with
1013-- `.&&`.
776-- `.&&`.
1014−data HavingClause outer commons grp schemas params from where
777+data HavingClause relations grouping params where
1015− NoHaving :: HavingClause outer commons 'Ungrouped schemas params from
778+ NoHaving :: HavingClause relations 'Ungrouped params
1017− :: [Condition outer commons ('Grouped bys) schemas params from]
780+ :: [Condition relations ('Grouped bys) params]
1018− -> HavingClause outer commons ('Grouped bys) schemas params from
781+ -> HavingClause relations ('Grouped bys) params
1019−deriving instance Show (HavingClause outer commons grp schemas params from)
782+deriving instance Show (HavingClause relations grouping params)
1020−deriving instance Eq (HavingClause outer commons grp schemas params from)
783+deriving instance Eq (HavingClause relations grouping params)
1021−deriving instance Ord (HavingClause outer commons grp schemas params from)
784+deriving instance Ord (HavingClause relations grouping params)
1023-- | Render a `HavingClause`.
786-- | Render a `HavingClause`.
1024−instance RenderSQL (HavingClause outer commons grp schemas params from) where
787+renderHavingClause :: HavingClause relations grouping params -> ByteString
1025− renderSQL = \case
788+renderHavingClause = \case
1026− NoHaving -> ""
789+ NoHaving -> ""
1027− Having [] -> ""
790+ Having [] -> ""
1028− Having conditions ->
791+ Having conditions ->
1029− " HAVING" <+> commaSeparated (renderSQL <$> conditions)
792+ " HAVING" <+> commaSeparated (renderExpression <$> conditions)
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)
1042− , commons1 ~ (cte ::: common ': commons)
1044− (statement commons schemas params common)
1045− (CommonTableExpression statement schemas params commons commons1) where
1046− statement `as` cte = CommonTableExpression (statement `as` cte)
1049− , commons1 ~ (cte ::: common ': commons)
1051− (statement commons schemas params common)
1052− (Path (CommonTableExpression statement schemas params) commons commons1) where
1053− statement `as` cte = csingleton (statement `as` cte)
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)
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
1065− :: Path (CommonTableExpression statement schemas params) commons0 commons1
1066− -- ^ common table expressions
1067− -> statement commons1 schemas params row
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
1075−{- |
794+{-----------------------------------------
1076−>>> import Data.Monoid (Sum (..))
795+Sorting
1077−>>> import Data.Int (Int64)
796+-----------------------------------------}
1079− let
798+-- | `SortExpression`s are used by `sortBy` to optionally sort the results
1080− query :: Query_ schema () (Sum Int64)
799+-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result
1081− query = withRecursive
800+-- column to ascending or descending. Ascending order puts smaller values
1082− ( values_ ((1 & astype int) `as` #n)
801+-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,
1083− `unionAll`
802+-- descending order is determined with the `.>` operator. `AscNullsFirst`,
1084− select_ ((#n + 1) `as` #n)
803+-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to
1085− (from (common #t) & where_ (#n .< 100)) `as` #t )
804+-- determine whether nulls appear before or after non-null values in the sort
1086− ( select_ (fromNull 0 (sum_ (All #n)) `as` #getSum) (from (common #t) & groupBy Nil))
805+-- ordering of a `Null` result column.
1087− in printSQL query
806+data SortExpression relations grouping params where
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"
808+ :: Expression relations grouping params ('NotNull ty)
1090−-}
809+ -> SortExpression relations grouping params
1091−withRecursive
810+ Desc
1092− :: Aliased (Query outer (recursive ': commons) schemas params) recursive
811+ :: Expression relations grouping params ('NotNull ty)
1093− -> Query outer (recursive ': commons) schemas params row
812+ -> SortExpression relations grouping params
1094− -> Query outer commons schemas params row
813+ AscNullsFirst
1095−withRecursive (recursive `As` cte) query = UnsafeQuery $
814+ :: Expression relations grouping params ('Null ty)
1096− "WITH RECURSIVE" <+> renderSQL cte
815+ -> SortExpression relations grouping params
1097− <+> "AS" <+> parenthesized (renderSQL recursive)
816+ AscNullsLast
1098− <+> renderSQL query
817+ :: Expression relations grouping params ('Null ty)
818+ -> SortExpression relations grouping params
820+ :: Expression relations grouping params ('Null ty)
821+ -> SortExpression relations grouping params
823+ :: Expression relations grouping params ('Null ty)
824+ -> SortExpression relations grouping params
825+deriving instance Show (SortExpression relations grouping params)
827+-- | Render a `SortExpression`.
828+renderSortExpression :: SortExpression relations grouping params -> ByteString
829+renderSortExpression = \case
830+ Asc expression -> renderExpression expression <+> "ASC"
831+ Desc expression -> renderExpression expression <+> "DESC"
832+ AscNullsFirst expression -> renderExpression expression
833+ <+> "ASC NULLS FIRST"
834+ DescNullsFirst expression -> renderExpression expression
835+ <+> "DESC NULLS FIRST"
836+ AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"
837+ DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"