@@ -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+ DataKinds
13 , DeriveGeneric
14 , DeriveGeneric
14 , FlexibleContexts
15 , FlexibleContexts
15 , FlexibleInstances
16 , FlexibleInstances
17 , GeneralizedNewtypeDeriving
18 , GeneralizedNewtypeDeriving
18 , LambdaCase
20 , LambdaCase
19 , MultiParamTypeClasses
21 , MultiParamTypeClasses
21 , OverloadedStrings
22 , OverloadedStrings
22− , QuantifiedConstraints
23 , ScopedTypeVariables
23 , ScopedTypeVariables
24 , StandaloneDeriving
24 , StandaloneDeriving
25 , TypeApplications
25 , TypeApplications
27 , TypeInType
26 , TypeInType
28 , TypeOperators
27 , TypeOperators
30 , UndecidableInstances
28 , UndecidableInstances
33module Squeal.PostgreSQL.Query
31module Squeal.PostgreSQL.Query
34 ( -- * Queries
32 ( -- * Queries
35− Query_
33+ Query (UnsafeQuery, renderQuery)
50 , unionAll
35 , unionAll
51 , intersect
36 , intersect
52 , intersectAll
37 , intersectAll
54 , exceptAll
39 , exceptAll
55− -- ** With
40+ -- * Select
56− , With (..)
41+ , select
57− , CommonTableExpression (..)
42+ , selectDistinct
58− , withRecursive
43+ , selectStar
46+ , selectDistinctDotStar
59 -- * Table Expressions
47 -- * Table Expressions
60 , TableExpression (..)
48 , TableExpression (..)
49+ , renderTableExpression
67− -- * From Clauses
57+ -- * From
68 , FromClause (..)
58 , FromClause (..)
69− , table
59+ , renderFromClause
78 -- * Grouping
60 -- * Grouping
79− , By (..)
61+ , By (By, By2)
80− , GroupByClause (..)
63+ , GroupByClause (NoGroups, Group)
64+ , renderGroupByClause
81− , HavingClause (..)
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)
@@ -91,577 +79,353 @@ 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
83+import Squeal.PostgreSQL.Prettyprint
97−import Squeal.PostgreSQL.Expression.Sort
98−import Squeal.PostgreSQL.Expression.Window
99−import Squeal.PostgreSQL.List
100−import Squeal.PostgreSQL.PG
101−import Squeal.PostgreSQL.Render
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
97+ '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
99+ '["col" ::: 'Null 'PGint4]
163− query = select Star (from (table #tab))
100+ query = selectStar (from (Table (#tab `As` #t)))
164−in printSQL query
101+in renderQuery query
166−SELECT * FROM "tab" AS "tab"
103+"SELECT * FROM tab AS t"
168restricted query:
105restricted query:
172− query :: Query_ (Public Schema) () (Row Int32 Int32)
109+ query :: Query
110+ '[ "tab" ::: '[] :=>
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)
118+ ((#col1 + #col2) `As` #sum :* #col1 `As` #col1 :* Nil)
175− ( from (table #tab)
119+ ( from (Table (#tab `As` #t))
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 t 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" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
133+ '["col" ::: 'Null 'PGint4]
136+ (from (Subquery (selectStar (from (Table (#tab `As` #t))) `As` #sub)))
188−in printSQL query
137+in renderQuery query
190−SELECT * FROM (SELECT * FROM "tab" AS "tab") AS "sub"
139+"SELECT * FROM (SELECT * FROM tab AS t) AS sub"
192limits and offsets:
141limits and offsets:
196− query :: Query_ (Public Schema) () (Row Int32 Int32)
145+ query :: Query
146+ '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
148+ '["col" ::: 'Null 'PGint4]
197− query = select Star (from (table #tab) & limit 100 & offset 2 & limit 50 & offset 2)
150+ (from (Table (#tab `As` #t)) & limit 100 & offset 2 & limit 50 & offset 2)
198−in printSQL query
151+in renderQuery query
200−SELECT * FROM "tab" AS "tab" LIMIT 50 OFFSET 4
153+"SELECT * FROM tab AS t LIMIT 50 OFFSET 4"
202parameterized query:
155parameterized query:
206− query :: Query_ (Public Schema) (Only Int32) (Row Int32 Int32)
159+ query :: Query
160+ '["tab" ::: '[] :=> '["col" ::: 'NoDef :=> 'NotNull 'PGfloat8]]
161+ '[ 'NotNull 'PGfloat8]
162+ '["col" ::: 'NotNull 'PGfloat8]
207− query = select Star (from (table #tab) & where_ (#col1 .> param @1))
164+ (from (Table (#tab `As` #t)) & where_ (#col .> param @1))
208−in printSQL query
165+in renderQuery query
210−SELECT * FROM "tab" AS "tab" WHERE ("col1" > ($1 :: int4))
167+"SELECT * FROM tab AS t WHERE (col > ($1 :: float8))"
212aggregation query:
169aggregation query:
216− query :: Query_ (Public Schema) () (Row Int64 Int32)
173+ query :: Query
174+ '[ "tab" ::: '[] :=>
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 `As` #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" ::: '[] :=> '["col" ::: 'NoDef :=> 'Null 'PGint4]]
196+ '["col" ::: 'Null 'PGint4]
198+ (from (Table (#tab `As` #t)) & orderBy [#col & AscNullsFirst])
232−in printSQL query
199+in renderQuery query
234−SELECT * FROM "tab" AS "tab" ORDER BY "col1" ASC
201+"SELECT * FROM tab AS t 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" :::
277− ( #o ! #price `as` #price :*
210+ '["pk" ::: PrimaryKey '["id"]
278− #c ! #name `as` #customerName :*
211+ ,"fk_customer" ::: ForeignKey '["customer_id"] "customers" '["id"]
279− #s ! #name `as` #shipperName )
212+ ,"fk_shipper" ::: 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
219+ '["pk" ::: PrimaryKey '["id"]] :=>
220+ '[ "id" ::: 'NoDef :=> 'NotNull 'PGint4
221+ , "name" ::: 'NoDef :=> 'NotNull 'PGtext
224+ '["pk" ::: 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" ::: '[] :=> '["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" ::: '[] :=> '["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 `As` #t)))
355− & where_ (exists (
271+ `unionAll`
356− select Star (from (table (#tab `as` #t2))
272+ selectStar (from (Table (#tab `As` #t)))
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 t) UNION ALL (SELECT * FROM tab AS t)"
363−type family Query_
277+
364− (schemas :: SchemasType)
278+newtype Query
365− (parameters :: Type)
279+ (schema :: TablesType)
366− (row :: Type) where
280+ (params :: [NullityType])
367− Query_ schemas params row =
281+ (columns :: RelationType)
368− Query '[] '[] schemas (TuplePG params) (RowPG row)
282+ = UnsafeQuery { renderQuery :: ByteString }
283+ deriving (GHC.Generic,Show,Eq,Ord,NFData)
370-- | The results of two queries can be combined using the set operation
285-- | The results of two queries can be combined using the set operation
371−-- `union`. Duplicate rows are eliminated.
286+-- `union`. Duplicate rows are eliminated.
373− :: Query outer commons schemas params columns
288+ :: Query schema params columns
374− -> Query outer commons schemas params columns
289+ -> Query schema params columns
375− -> Query outer commons schemas params columns
290+ -> Query schema params columns
376q1 `union` q2 = UnsafeQuery $
291q1 `union` q2 = UnsafeQuery $
377− parenthesized (renderSQL q1)
292+ parenthesized (renderQuery q1)
378 <+> "UNION"
293 <+> "UNION"
379− <+> parenthesized (renderSQL q2)
294+ <+> parenthesized (renderQuery q2)
381-- | The results of two queries can be combined using the set operation
296-- | The results of two queries can be combined using the set operation
382-- `unionAll`, the disjoint union. Duplicate rows are retained.
297-- `unionAll`, the disjoint union. Duplicate rows are retained.
384− :: Query outer commons schemas params columns
299+ :: Query schema params columns
385− -> Query outer commons schemas params columns
300+ -> Query schema params columns
386− -> Query outer commons schemas params columns
301+ -> Query schema params columns
387q1 `unionAll` q2 = UnsafeQuery $
302q1 `unionAll` q2 = UnsafeQuery $
388− parenthesized (renderSQL q1)
303+ parenthesized (renderQuery q1)
389 <+> "UNION" <+> "ALL"
304 <+> "UNION" <+> "ALL"
390− <+> parenthesized (renderSQL q2)
305+ <+> parenthesized (renderQuery q2)
392-- | The results of two queries can be combined using the set operation
307-- | The results of two queries can be combined using the set operation
393-- `intersect`, the intersection. Duplicate rows are eliminated.
308-- `intersect`, the intersection. Duplicate rows are eliminated.
395− :: Query outer commons schemas params columns
310+ :: Query schema params columns
396− -> Query outer commons schemas params columns
311+ -> Query schema params columns
397− -> Query outer commons schemas params columns
312+ -> Query schema params columns
398q1 `intersect` q2 = UnsafeQuery $
313q1 `intersect` q2 = UnsafeQuery $
399− parenthesized (renderSQL q1)
314+ parenthesized (renderQuery q1)
400 <+> "INTERSECT"
315 <+> "INTERSECT"
401− <+> parenthesized (renderSQL q2)
316+ <+> parenthesized (renderQuery q2)
403-- | The results of two queries can be combined using the set operation
318-- | The results of two queries can be combined using the set operation
404-- `intersectAll`, the intersection. Duplicate rows are retained.
319-- `intersectAll`, the intersection. Duplicate rows are retained.
405intersectAll
320intersectAll
406− :: Query outer commons schemas params columns
321+ :: Query schema params columns
407− -> Query outer commons schemas params columns
322+ -> Query schema params columns
408− -> Query outer commons schemas params columns
323+ -> Query schema params columns
409q1 `intersectAll` q2 = UnsafeQuery $
324q1 `intersectAll` q2 = UnsafeQuery $
410− parenthesized (renderSQL q1)
325+ parenthesized (renderQuery q1)
411 <+> "INTERSECT" <+> "ALL"
326 <+> "INTERSECT" <+> "ALL"
412− <+> parenthesized (renderSQL q2)
327+ <+> parenthesized (renderQuery q2)
414-- | The results of two queries can be combined using the set operation
329-- | The results of two queries can be combined using the set operation
415-- `except`, the set difference. Duplicate rows are eliminated.
330-- `except`, the set difference. Duplicate rows are eliminated.
417− :: Query outer commons schemas params columns
332+ :: Query schema params columns
418− -> Query outer commons schemas params columns
333+ -> Query schema params columns
419− -> Query outer commons schemas params columns
334+ -> Query schema params columns
420q1 `except` q2 = UnsafeQuery $
335q1 `except` q2 = UnsafeQuery $
421− parenthesized (renderSQL q1)
336+ parenthesized (renderQuery q1)
422 <+> "EXCEPT"
337 <+> "EXCEPT"
423− <+> parenthesized (renderSQL q2)
338+ <+> parenthesized (renderQuery q2)
425-- | The results of two queries can be combined using the set operation
340-- | The results of two queries can be combined using the set operation
426-- `exceptAll`, the set difference. Duplicate rows are retained.
341-- `exceptAll`, the set difference. Duplicate rows are retained.
428− :: Query outer commons schemas params columns
343+ :: Query schema params columns
429− -> Query outer commons schemas params columns
344+ -> Query schema params columns
430− -> Query outer commons schemas params columns
345+ -> Query schema params columns
431q1 `exceptAll` q2 = UnsafeQuery $
346q1 `exceptAll` q2 = UnsafeQuery $
432− parenthesized (renderSQL q1)
347+ parenthesized (renderQuery q1)
433 <+> "EXCEPT" <+> "ALL"
348 <+> "EXCEPT" <+> "ALL"
434− <+> parenthesized (renderSQL q2)
349+ <+> parenthesized (renderQuery q2)
436{-----------------------------------------
351{-----------------------------------------
437SELECT queries
352SELECT queries
438-----------------------------------------}
353-----------------------------------------}
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
355-- | the `TableExpression` in the `select` command constructs an intermediate
526-- virtual table by possibly combining tables, views, eliminating rows,
356-- virtual table by possibly combining tables, views, eliminating rows,
527-- grouping, etc. This table is finally passed on to processing by
357-- grouping, etc. This table is finally passed on to processing by
528−-- the select list. The `Selection` determines which columns of
358+-- the select list. The select list determines which columns of
529-- the intermediate table are actually output.
359-- the intermediate table are actually output.
531− :: (SListI row, row ~ (x ': xs))
361+ :: SListI columns
532− => Selection outer commons grp schemas params from row
362+ => NP (Aliased (Expression tables 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
363 -- ^ select list
548− -> TableExpression outer commons grp schemas params from
364+ -> TableExpression schema params tables grouping
549 -- ^ intermediate virtual table
365 -- ^ intermediate virtual table
550− -> Query outer commons schemas params row
366+ -> Query schema params (column ': columns)
551−select_ = select . List
367+select list tabs = UnsafeQuery $
369+ <+> renderCommaSeparated (renderAliasedAs renderExpression) list
370+ <+> renderTableExpression tabs
553-- | After the select list has been processed, the result table can
372-- | After the select list has been processed, the result table can
554-- be subject to the elimination of duplicate rows using `selectDistinct`.
373-- be subject to the elimination of duplicate rows using `selectDistinct`.
555selectDistinct
374selectDistinct
556− :: (SListI columns, columns ~ (col ': cols))
375+ :: SListI columns
557− => Selection outer commons grp schemas params from columns
376+ => NP (Aliased (Expression tables 'Ungrouped params)) (column ': columns)
558− -- ^ selection
377+ -- ^ select list
559− -> TableExpression outer commons grp schemas params from
378+ -> TableExpression schema params tables 'Ungrouped
560 -- ^ intermediate virtual table
379 -- ^ intermediate virtual table
561− -> Query outer commons schemas params columns
380+ -> Query schema params (column ': columns)
562−selectDistinct selection tabexpr = UnsafeQuery $
381+selectDistinct list tabs = UnsafeQuery $
563 "SELECT DISTINCT"
382 "SELECT DISTINCT"
564− <+> renderSQL selection
383+ <+> renderCommaSeparated (renderAliasedAs renderExpression) list
565− <+> renderSQL tabexpr
384+ <+> renderTableExpression tabs
567−-- | Like `selectDistinct` but takes an `NP` list of `Expression`s instead
386+-- | The simplest kind of query is `selectStar` which emits all columns
568−-- of a general `Selection`.
387+-- that the table expression produces.
569−selectDistinct_
388+selectStar
570− :: (SListI columns, columns ~ (col ': cols))
389+ :: HasUnique table tables columns
571− => NP (Aliased (Expression outer commons grp schemas params from)) columns
390+ => TableExpression schema params tables 'Ungrouped
573− -> TableExpression outer commons grp schemas params from
574 -- ^ intermediate virtual table
391 -- ^ intermediate virtual table
575− -> Query outer commons schemas params columns
392+ -> Query schema params columns
576−selectDistinct_ = selectDistinct . List
393+selectStar tabs = UnsafeQuery $ "SELECT" <+> "*" <+> renderTableExpression tabs
578−{-|
395+-- | A `selectDistinctStar` emits all columns that the table expression
579−`selectDistinctOn` keeps only the first row of each set of rows where
396+-- produces and eliminates duplicate rows.
580−the given expressions evaluate to equal. The DISTINCT ON expressions are
397+selectDistinctStar
581−interpreted using the same rules as for ORDER BY. ORDER BY is used to
398+ :: HasUnique table tables columns
582−ensure that the desired row appears first.
399+ => TableExpression schema params tables '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
400 -- ^ intermediate virtual table
599− -> Query outer commons schemas params columns
401+ -> Query schema params columns
600−selectDistinctOn distincts selection tab = UnsafeQuery $
402+selectDistinctStar tabs = UnsafeQuery $
601− "SELECT DISTINCT ON"
403+ "SELECT DISTINCT" <+> "*" <+> renderTableExpression tabs
602− <+> parenthesized (commaSeparated (renderDistinctOn <$> distincts))
404+
603− <+> renderSQL selection
405+-- | When working with multiple tables, it can also be useful to ask
604− <+> renderSQL (tab {orderByClause = distincts <> orderByClause tab})
406+-- for all the columns of a particular table, using `selectDotStar`.
605− where
407+selectDotStar
606− renderDistinctOn = \case
408+ :: Has table tables columns
607− Asc expression -> renderSQL expression
409+ => Alias table
608− Desc expression -> renderSQL expression
410+ -- ^ particular virtual Table
609− AscNullsFirst expression -> renderSQL expression
411+ -> TableExpression schema params tables 'Ungrouped
610− DescNullsFirst expression -> renderSQL expression
611− AscNullsLast expression -> renderSQL expression
612− DescNullsLast expression -> renderSQL expression
614−-- | Like `selectDistinctOn` but takes an `NP` list of `Expression`s instead
615−-- of a general `Selection`.
617− :: (SListI columns, columns ~ (col ': cols))
618− => [SortExpression outer commons grp schemas params from]
619− -- ^ distinct on and return the first row in ordering
620− -> NP (Aliased (Expression outer commons grp schemas params from)) columns
622− -> TableExpression outer commons grp schemas params from
623 -- ^ intermediate virtual table
412 -- ^ intermediate virtual table
624− -> Query outer commons schemas params columns
413+ -> Query schema params columns
625−selectDistinctOn_ distincts = selectDistinctOn distincts . List
414+selectDotStar table tables = UnsafeQuery $
626−
415+ "SELECT" <+> renderAlias table <> ".*" <+> renderTableExpression tables
627−-- | `values` computes a row value or set of row values
416+
628−-- specified by value expressions. It is most commonly used
417+-- | A `selectDistinctDotStar` asks for all the columns of a particular table,
629−-- to generate a “constant table” within a larger command,
418+-- and eliminates duplicate rows.
630−-- but it can be used on its own.
419+selectDistinctDotStar
631−--
420+ :: Has table tables columns
632−-- >>> type Row = '["a" ::: 'NotNull 'PGint4, "b" ::: 'NotNull 'PGtext]
421+ => Alias table
633−-- >>> let query = values (1 `as` #a :* "one" `as` #b) [] :: Query outer commons schemas '[] Row
422+ -- ^ particular virtual Table
634−-- >>> printSQL query
423+ -> TableExpression schema params tables 'Ungrouped
635−-- SELECT * FROM (VALUES (1, E'one')) AS t ("a", "b")
424+ -- ^ intermediate virtual table
636−values
425+ -> Query schema params columns
637− :: SListI cols
426+selectDistinctDotStar table tables = UnsafeQuery $
638− => NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols
427+ "SELECT DISTINCT" <+> renderAlias table <> ".*"
639− -> [NP (Aliased (Expression outer commons 'Ungrouped schemas params '[] )) cols]
428+ <+> renderTableExpression tables
640− -- ^ When more than one row is specified, all the rows must
641− -- must have the same number of elements
642− -> Query outer commons schemas params cols
643−values rw rws = UnsafeQuery $ "SELECT * FROM"
648− . renderCommaSeparated renderValuePart <$> rw:rws )
650− <+> parenthesized (renderCommaSeparated renderAliasPart rw)
652− renderAliasPart, renderValuePart
653− :: Aliased (Expression outer commons 'Ungrouped schemas params '[] ) ty -> ByteString
654− renderAliasPart (_ `As` name) = renderSQL name
655− renderValuePart (value `As` _) = renderSQL value
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{-----------------------------------------
430{-----------------------------------------
667Table Expressions
431Table Expressions
@@ -674,17 +438,15 @@ Table Expressions
674-- to a table on disk, a so-called base table, but more complex expressions
438-- 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.
439-- can be used to modify or combine base tables in various ways.
676data TableExpression
440data TableExpression
677− (outer :: FromType)
441+ (schema :: TablesType)
678− (commons :: FromType)
680− (schemas :: SchemasType)
681 (params :: [NullityType])
442 (params :: [NullityType])
682− (from :: FromType)
443+ (tables :: RelationsType)
444+ (grouping :: Grouping)
683 = TableExpression
445 = TableExpression
684− { fromClause :: FromClause outer commons schemas params from
446+ { fromClause :: FromClause schema params tables
685 -- ^ A table reference that can be a table name, or a derived table such
447 -- ^ 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.
448 -- as a subquery, a @JOIN@ construct, or complex combinations of these.
687− , whereClause :: [Condition outer commons 'Ungrouped schemas params from]
449+ , whereClause :: [Condition tables 'Ungrouped params]
688 -- ^ optional search coditions, combined with `.&&`. After the processing
450 -- ^ optional search coditions, combined with `.&&`. After the processing
689 -- of the `fromClause` is done, each row of the derived virtual table
451 -- of the `fromClause` is done, each row of the derived virtual table
690 -- is checked against the search condition. If the result of the
452 -- is checked against the search condition. If the result of the
@@ -693,20 +455,20 @@ data TableExpression
693 -- at least one column of the table generated in the `fromClause`;
455 -- at least one column of the table generated in the `fromClause`;
694 -- this is not required, but otherwise the WHERE clause will
456 -- this is not required, but otherwise the WHERE clause will
695 -- be fairly useless.
457 -- be fairly useless.
696− , groupByClause :: GroupByClause grp from
458+ , groupByClause :: GroupByClause tables grouping
697 -- ^ The `groupByClause` is used to group together those rows in a table
459 -- ^ 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
460 -- 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
461 -- 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
462 -- 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
463 -- rows in the group. This is done to eliminate redundancy in the output
702 -- and/or compute aggregates that apply to these groups.
464 -- and/or compute aggregates that apply to these groups.
703− , havingClause :: HavingClause outer commons grp schemas params from
465+ , havingClause :: HavingClause tables grouping params
704 -- ^ If a table has been grouped using `groupBy`, but only certain groups
466 -- ^ If a table has been grouped using `groupBy`, but only certain groups
705 -- are of interest, the `havingClause` can be used, much like a
467 -- are of interest, the `havingClause` can be used, much like a
706 -- `whereClause`, to eliminate groups from the result. Expressions in the
468 -- `whereClause`, to eliminate groups from the result. Expressions in the
707 -- `havingClause` can refer both to grouped expressions and to ungrouped
469 -- `havingClause` can refer both to grouped expressions and to ungrouped
708 -- expressions (which necessarily involve an aggregate function).
470 -- expressions (which necessarily involve an aggregate function).
709− , orderByClause :: [SortExpression outer commons grp schemas params from]
471+ , orderByClause :: [SortExpression tables grouping params]
710 -- ^ The `orderByClause` is for optional sorting. When more than one
472 -- ^ The `orderByClause` is for optional sorting. When more than one
711 -- `SortExpression` is specified, the later (right) values are used to sort
473 -- `SortExpression` is specified, the later (right) values are used to sort
712 -- rows that are equal according to the earlier (left) values.
474 -- rows that are equal according to the earlier (left) values.
@@ -716,102 +478,110 @@ data TableExpression
716 -- will be returned (but possibly fewer, if the query itself yields
478 -- will be returned (but possibly fewer, if the query itself yields
717 -- fewer rows).
479 -- fewer rows).
718 , offsetClause :: [Word64]
480 , offsetClause :: [Word64]
719− -- ^ The `offsetClause` is combined with `Prelude.+` to give an offset count
481+ -- ^ The `offsetClause` is combined with `+` to give an offset count
720 -- if nonempty. The offset count says to skip that many rows before
482 -- 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
483 -- beginning to return rows. The rows are skipped before the limit count
722 -- is applied.
484 -- is applied.
723− } deriving (GHC.Generic)
485+ }
725-- | Render a `TableExpression`
487-- | Render a `TableExpression`
726−instance RenderSQL (TableExpression outer commons grp schemas params from) where
488+renderTableExpression
727− renderSQL
489+ :: TableExpression schema params tables grouping
728− (TableExpression frm' whs' grps' hvs' srts' lims' offs') = mconcat
490+ -> ByteString
729− [ "FROM ", renderSQL frm'
491+renderTableExpression
730− , renderWheres whs'
492+ (TableExpression tables whs' grps' hvs' srts' lims' offs') = mconcat
731− , renderSQL grps'
493+ [ "FROM ", renderFromClause tables
732− , renderSQL hvs'
494+ , renderWheres whs'
733− , renderOrderByClause srts'
495+ , renderGroupByClause grps'
734− , renderLimits lims'
496+ , renderHavingClause hvs'
735− , renderOffsets offs' ]
497+ , renderOrderByClause srts'
736− where
498+ , renderLimits lims'
737− renderWheres = \case
499+ , renderOffsets offs'
739− wh:[] -> " WHERE" <+> renderSQL wh
501+ where
740− wh:whs -> " WHERE" <+> renderSQL (foldr (.&&) wh whs)
502+ renderWheres = \case
741− renderOrderByClause = \case
503+ [] -> ""
742− [] -> ""
504+ wh:[] -> " WHERE" <+> renderExpression wh
743− srts -> " ORDER BY"
505+ wh:whs -> " WHERE" <+> renderExpression (foldr (.&&) wh whs)
744− <+> commaSeparated (renderSQL <$> srts)
506+ renderOrderByClause = \case
745− renderLimits = \case
507+ [] -> ""
746− [] -> ""
508+ srts -> " ORDER BY"
747− lims -> " LIMIT" <+> fromString (show (minimum lims))
509+ <+> commaSeparated (renderSortExpression <$> srts)
748− renderOffsets = \case
510+ renderLimits = \case
749− [] -> ""
511+ [] -> ""
750− offs -> " OFFSET" <+> fromString (show (sum offs))
512+ lims -> " LIMIT" <+> fromString (show (minimum lims))
513+ renderOffsets = \case
515+ offs -> " OFFSET" <+> fromString (show (sum offs))
752-- | A `from` generates a `TableExpression` from a table reference that can be
517-- | 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,
518-- 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_`,
519-- or complex combinations of these. A `from` may be transformed by `where_`,
755−-- `groupBy`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
520+-- `group`, `having`, `orderBy`, `limit` and `offset`, using the `&` operator
756-- to match the left-to-right sequencing of their placement in SQL.
521-- to match the left-to-right sequencing of their placement in SQL.
758− :: FromClause outer commons schemas params from -- ^ table reference
523+ :: FromClause schema params tables -- ^ table reference
759− -> TableExpression outer commons 'Ungrouped schemas params from
524+ -> TableExpression schema params tables 'Ungrouped
760−from tab = TableExpression tab [] noGroups NoHaving [] [] []
525+from tables = TableExpression tables [] NoGroups NoHaving [] [] []
762-- | A `where_` is an endomorphism of `TableExpression`s which adds a
527-- | A `where_` is an endomorphism of `TableExpression`s which adds a
763-- search condition to the `whereClause`.
528-- search condition to the `whereClause`.
765− :: Condition outer commons 'Ungrouped schemas params from -- ^ filtering condition
530+ :: Condition tables 'Ungrouped params
766− -> TableExpression outer commons grp schemas params from
531+ -> TableExpression schema params tables grouping
767− -> TableExpression outer commons grp schemas params from
532+ -> TableExpression schema params tables grouping
768−where_ wh rels = rels {whereClause = wh : whereClause rels}
533+where_ wh tables = tables {whereClause = wh : whereClause tables}
770−-- | A `groupBy` is a transformation of `TableExpression`s which switches
535+-- | A `group` is a transformation of `TableExpression`s which switches
771−-- its `Grouping` from `Ungrouped` to `Grouped`. Use @groupBy Nil@ to perform
536+-- its `Grouping` from `Ungrouped` to `Grouped`. Use @group Nil@ to perform
772-- a "grand total" aggregation query.
537-- a "grand total" aggregation query.
774 :: SListI bys
539 :: SListI bys
775− => NP (By from) bys -- ^ grouped columns
540+ => NP (By tables) bys
776− -> TableExpression outer commons 'Ungrouped schemas params from
541+ -> TableExpression schema params tables 'Ungrouped
777− -> TableExpression outer commons ('Grouped bys) schemas params from
542+ -> TableExpression schema params tables ('Grouped bys)
778−groupBy bys rels = TableExpression
543+group bys tables = TableExpression
779− { fromClause = fromClause rels
544+ { fromClause = fromClause tables
780− , whereClause = whereClause rels
545+ , whereClause = whereClause tables
781− , groupByClause = group bys
546+ , groupByClause = Group bys
782 , havingClause = Having []
547 , havingClause = Having []
783 , orderByClause = []
548 , orderByClause = []
784− , limitClause = limitClause rels
549+ , limitClause = limitClause tables
785− , offsetClause = offsetClause rels
550+ , offsetClause = offsetClause tables
788-- | A `having` is an endomorphism of `TableExpression`s which adds a
553-- | A `having` is an endomorphism of `TableExpression`s which adds a
789-- search condition to the `havingClause`.
554-- search condition to the `havingClause`.
791− :: Condition outer commons ('Grouped bys) schemas params from -- ^ having condition
556+ :: Condition tables ('Grouped bys) params
792− -> TableExpression outer commons ('Grouped bys) schemas params from
557+ -> TableExpression schema params tables ('Grouped bys)
793− -> TableExpression outer commons ('Grouped bys) schemas params from
558+ -> TableExpression schema params tables ('Grouped bys)
794−having hv rels = rels
559+having hv tables = tables
795− { havingClause = case havingClause rels of Having hvs -> Having (hv:hvs) }
560+ { havingClause = case havingClause tables of Having hvs -> Having (hv:hvs) }
797−instance OrderBy TableExpression where
562+-- | An `orderBy` is an endomorphism of `TableExpression`s which appends an
798− orderBy srts rels = rels {orderByClause = orderByClause rels ++ srts}
563+-- ordering to the right of the `orderByClause`.
565+ :: [SortExpression tables grouping params]
566+ -> TableExpression schema params tables grouping
567+ -> TableExpression schema params tables grouping
568+orderBy srts tables = tables {orderByClause = orderByClause tables ++ srts}
800-- | A `limit` is an endomorphism of `TableExpression`s which adds to the
570-- | A `limit` is an endomorphism of `TableExpression`s which adds to the
801-- `limitClause`.
571-- `limitClause`.
803− :: Word64 -- ^ limit parameter
573+ :: Word64
804− -> TableExpression outer commons grp schemas params from
574+ -> TableExpression schema params tables grouping
805− -> TableExpression outer commons grp schemas params from
575+ -> TableExpression schema params tables grouping
806−limit lim rels = rels {limitClause = lim : limitClause rels}
576+limit lim tables = tables {limitClause = lim : limitClause tables}
808-- | An `offset` is an endomorphism of `TableExpression`s which adds to the
578-- | An `offset` is an endomorphism of `TableExpression`s which adds to the
809-- `offsetClause`.
579-- `offsetClause`.
811− :: Word64 -- ^ offset parameter
581+ :: Word64
812− -> TableExpression outer commons grp schemas params from
582+ -> TableExpression schema params tables grouping
813− -> TableExpression outer commons grp schemas params from
583+ -> TableExpression schema params tables grouping
814−offset off rels = rels {offsetClause = off : offsetClause rels}
584+offset off tables = tables {offsetClause = off : offsetClause tables}
816{-----------------------------------------
586{-----------------------------------------
817FROM clauses
587FROM clauses
@@ -820,279 +590,205 @@ FROM clauses
821A `FromClause` can be a table name, or a derived table such
591A `FromClause` can be a table name, or a derived table such
822as a subquery, a @JOIN@ construct, or complex combinations of these.
592as a subquery, a @JOIN@ construct, or complex combinations of these.
824−newtype FromClause outer commons schemas params from
825− = UnsafeFromClause { renderFromClause :: ByteString }
826− deriving (GHC.Generic,Show,Eq,Ord,NFData)
827−instance RenderSQL (FromClause outer commons schemas params from) where
828− renderSQL = renderFromClause
830−-- | A real `table` is a table from the database.
832− :: (Has sch schemas schema, Has tab schema ('Table table))
833− => Aliased (QualifiedAlias sch) (alias ::: tab)
834− -> FromClause outer commons schemas params '[alias ::: TableToRow table]
835−table (tab `As` alias) = UnsafeFromClause $
836− renderSQL tab <+> "AS" <+> renderSQL alias
838−-- | `subquery` derives a table from a `Query`.
840− :: Aliased (Query outer commons schemas params) query
841− -> FromClause outer commons schemas params '[query]
842−subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)
844−-- | `view` derives a table from a `View`.
846− :: (Has sch schemas schema, Has vw schema ('View view))
847− => Aliased (QualifiedAlias sch) (alias ::: vw)
848− -> FromClause outer commons schemas params '[alias ::: view]
849−view (vw `As` alias) = UnsafeFromClause $
850− renderSQL vw <+> "AS" <+> renderSQL alias
852−-- | `common` derives a table from a common table expression.
854− :: Has cte commons common
855− => Aliased Alias (alias ::: cte)
856− -> FromClause outer commons schemas params '[alias ::: common]
857−common (cte `As` alias) = UnsafeFromClause $
858− renderSQL cte <+> "AS" <+> renderSQL alias
860−instance Additional (FromClause outer commons schemas params) where
861− also right left = UnsafeFromClause $
862− renderSQL left <> ", " <> renderSQL right
864−{- |
594+* A real `Table` is a table from the schema.
865−@left & crossJoin right@. For every possible combination of rows from
595+
866−@left@ and @right@ (i.e., a Cartesian product), the joined table will contain
596+* `Subquery` derives a table from a `Query`.
867−a row consisting of all columns in @left@ followed by all columns in @right@.
597+
868−If the tables have @n@ and @m@ rows respectively, the joined table will
598+* A joined table is a table derived from two other (real or derived) tables
869−have @n * m@ rows.
599+according to the rules of the particular join type. `CrossJoin`, `InnerJoin`,
870−-}
600+`LeftOuterJoin`, `RightOuterJoin` and `FullOuterJoin` are available and can
871−crossJoin
601+be nested using the `&` operator to match the left-to-right sequencing of
872− :: FromClause outer commons schemas params right
602+their placement in SQL.
874− -> FromClause outer commons schemas params left
604+ * @t1 & CrossJoin t2@. For every possible combination of rows from
875− -- ^ left
605+ @t1@ and @t2@ (i.e., a Cartesian product), the joined table will contain
876− -> FromClause outer commons schemas params (Join left right)
606+ a row consisting of all columns in @t1@ followed by all columns in @t2@.
877−crossJoin right left = UnsafeFromClause $
607+ If the tables have @n@ and @m@ rows respectively, the joined table will
878− renderSQL left <+> "CROSS JOIN" <+> renderSQL right
608+ have @n * m@ rows.
880−{- | @left & innerJoin right on@. The joined table is filtered by
610+ * @t1 & InnerJoin t2 on@. For each row @r1@ of @t1@, the joined
881−the @on@ condition.
611+ table has a row for each row in @t2@ that satisfies the @on@ condition
884− :: FromClause outer commons schemas params right
614+ * @t1 & LeftOuterJoin t2 on@. First, an inner join is performed.
885− -- ^ right
615+ Then, for each row in @t1@ that does not satisfy the @on@ condition with
886− -> Condition outer commons 'Ungrouped schemas params (Join left right)
616+ any row in @t2@, a joined row is added with null values in columns of @t2@.
887− -- ^ @on@ condition
617+ Thus, the joined table always has at least one row for each row in @t1@.
888− -> FromClause outer commons schemas params left
618+
889− -- ^ left
619+ * @t1 & RightOuterJoin t2 on@. First, an inner join is performed.
890− -> FromClause outer commons schemas params (Join left right)
620+ Then, for each row in @t2@ that does not satisfy the @on@ condition with
891−innerJoin right on left = UnsafeFromClause $
621+ any row in @t1@, a joined row is added with null values in columns of @t1@.
892− renderSQL left <+> "INNER JOIN" <+> renderSQL right
893− <+> "ON" <+> renderSQL on
895−{- | @left & leftOuterJoin right on@. First, an inner join is performed.
896− Then, for each row in @left@ that does not satisfy the @on@ condition with
897− any row in @right@, a joined row is added with null values in columns of @right@.
898− Thus, the joined table always has at least one row for each row in @left@.
901− :: FromClause outer commons schemas params right
903− -> Condition outer commons 'Ungrouped schemas params (Join left right)
905− -> FromClause outer commons schemas params left
907− -> FromClause outer commons schemas params (Join left (NullifyFrom right))
908−leftOuterJoin right on left = UnsafeFromClause $
909− renderSQL left <+> "LEFT OUTER JOIN" <+> renderSQL right
910− <+> "ON" <+> renderSQL on
912−{- | @left & rightOuterJoin right on@. First, an inner join is performed.
913− Then, for each row in @right@ that does not satisfy the @on@ condition with
914− any row in @left@, a joined row is added with null values in columns of @left@.
915 This is the converse of a left join: the result table will always
622 This is the converse of a left join: the result table will always
916− have a row for each row in @right@.
623+ have a row for each row in @t2@.
918−rightOuterJoin
625+ * @t1 & FullOuterJoin t2 on@. First, an inner join is performed.
919− :: FromClause outer commons schemas params right
626+ Then, for each row in @t1@ that does not satisfy the @on@ condition with
920− -- ^ right
627+ any row in @t2@, a joined row is added with null values in columns of @t2@.
921− -> Condition outer commons 'Ungrouped schemas params (Join left right)
628+ Also, for each row of @t2@ that does not satisfy the join condition
922− -- ^ @on@ condition
629+ with any row in @t1@, a joined row with null values in the columns of @t1@
923− -> FromClause outer commons schemas params left
925− -> FromClause outer commons schemas params (Join (NullifyFrom left) right)
926−rightOuterJoin right on left = UnsafeFromClause $
927− renderSQL left <+> "RIGHT OUTER JOIN" <+> renderSQL right
928− <+> "ON" <+> renderSQL on
930−{- | @left & fullOuterJoin right on@. First, an inner join is performed.
931− Then, for each row in @left@ that does not satisfy the @on@ condition with
932− any row in @right@, a joined row is added with null values in columns of @right@.
933− Also, for each row of @right@ that does not satisfy the join condition
934− with any row in @left@, a joined row with null values in the columns of @left@
935 is added.
630 is added.
937−fullOuterJoin
632+data FromClause schema params tables where
938− :: FromClause outer commons schemas params right
633+ Table
939− -- ^ right
634+ :: Aliased (Table schema) table
940− -> Condition outer commons 'Ungrouped schemas params (Join left right)
635+ -> FromClause schema params '[table]
941− -- ^ @on@ condition
636+ Subquery
942− -> FromClause outer commons schemas params left
637+ :: Aliased (Query schema params) table
943− -- ^ left
638+ -> FromClause schema params '[table]
944− -> FromClause outer commons schemas params
639+ CrossJoin
945− (Join (NullifyFrom left) (NullifyFrom right))
640+ :: FromClause schema params right
946−fullOuterJoin right on left = UnsafeFromClause $
641+ -> FromClause schema params left
947− renderSQL left <+> "FULL OUTER JOIN" <+> renderSQL right
642+ -> FromClause schema params (Join left right)
948− <+> "ON" <+> renderSQL on
643+ InnerJoin
644+ :: FromClause schema params right
645+ -> Condition (Join left right) 'Ungrouped params
646+ -> FromClause schema params left
647+ -> FromClause schema params (Join left right)
649+ :: FromClause schema params right
650+ -> Condition (Join left right) 'Ungrouped params
651+ -> FromClause schema params left
652+ -> FromClause schema params (Join left (NullifyTables right))
654+ :: FromClause schema params right
655+ -> Condition (Join left right) 'Ungrouped params
656+ -> FromClause schema params left
657+ -> FromClause schema params (Join (NullifyTables left) right)
659+ :: FromClause schema params right
660+ -> Condition (Join left right) 'Ungrouped params
661+ -> FromClause schema params left
662+ -> FromClause schema params
663+ (Join (NullifyTables left) (NullifyTables right))
665+-- | Renders a `FromClause`.
666+renderFromClause :: FromClause schema params tables -> ByteString
667+renderFromClause = \case
668+ Table table -> renderAliasedAs renderTable table
669+ Subquery selection -> renderAliasedAs (parenthesized . renderQuery) selection
670+ CrossJoin right left ->
671+ renderFromClause left <+> "CROSS JOIN" <+> renderFromClause right
672+ InnerJoin right on left -> renderJoin "INNER JOIN" right on left
673+ LeftOuterJoin right on left -> renderJoin "LEFT OUTER JOIN" right on left
674+ RightOuterJoin right on left -> renderJoin "RIGHT OUTER JOIN" right on left
675+ FullOuterJoin right on left -> renderJoin "FULL OUTER JOIN" right on left
677+ renderJoin op right on left =
678+ renderFromClause left <+> op <+> renderFromClause right
679+ <+> "ON" <+> renderExpression on
950{-----------------------------------------
681{-----------------------------------------
952-----------------------------------------}
683-----------------------------------------}
954−-- | `By`s are used in `groupBy` to reference a list of columns which are then
685+-- | `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
686-- 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
687-- in all the columns listed. @By \#col@ will reference an unambiguous
957-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
688-- column @col@; otherwise @By2 (\#tab \! \#col)@ will reference a table
958-- qualified column @tab.col@.
689-- qualified column @tab.col@.
960− (from :: FromType)
691+ (tables :: RelationsType)
961 (by :: (Symbol,Symbol)) where
692 (by :: (Symbol,Symbol)) where
963− :: (HasUnique table from columns, Has column columns ty)
694+ :: (HasUnique table tables columns, Has column columns ty)
964 => Alias column
695 => Alias column
965− -> By from '(table, column)
696+ -> By tables '(table, column)
967− :: (Has table from columns, Has column columns ty)
698+ :: (Has table tables columns, Has column columns ty)
968− => Alias table
699+ => (Alias table, Alias column)
969− -> Alias column
700+ -> By tables '(table, column)
970− -> By from '(table, column)
701+deriving instance Show (By tables by)
971−deriving instance Show (By from by)
702+deriving instance Eq (By tables by)
972−deriving instance Eq (By from by)
703+deriving instance Ord (By tables by)
973−deriving instance Ord (By from by)
704+
974−instance RenderSQL (By from by) where
705+-- | Renders a `By`.
975− renderSQL = \case
706+renderBy :: By tables tabcolty -> ByteString
976− By1 column -> renderSQL column
707+renderBy = \case
977− By2 rel column -> renderSQL rel <> "." <> renderSQL column
708+ By column -> renderAlias column
978−
709+ By2 (table, column) -> renderAlias table <> "." <> 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`.
711-- | A `GroupByClause` indicates the `Grouping` of a `TableExpression`.
990-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
712-- A `NoGroups` indicates `Ungrouped` while a `Group` indicates `Grouped`.
991-- @NoGroups@ is distinguised from @Group Nil@ since no aggregation can be
713-- @NoGroups@ is distinguised from @Group Nil@ since no aggregation can be
992-- done on @NoGroups@ while all output `Expression`s must be aggregated
714-- done on @NoGroups@ while all output `Expression`s must be aggregated
993−-- in @Group Nil@. In general, all output `Expression`s in the
715+-- in @Group Nil@.
994−-- complement of @bys@ must be aggregated in @Group bys@.
716+data GroupByClause tables grouping where
995−newtype GroupByClause grp from = UnsafeGroupByClause
717+ NoGroups :: GroupByClause tables 'Ungrouped
996− { renderGroupByClause :: ByteString }
718+ Group
997− deriving (GHC.Generic,Show,Eq,Ord,NFData)
719+ :: SListI bys
998−instance RenderSQL (GroupByClause grp from) where
720+ => NP (By tables) bys
999− renderSQL = renderGroupByClause
721+ -> GroupByClause tables ('Grouped bys)
1000−noGroups :: GroupByClause 'Ungrouped from
722+
1001−noGroups = UnsafeGroupByClause ""
723+-- | Renders a `GroupByClause`.
1002−group
724+renderGroupByClause :: GroupByClause tables grouping -> ByteString
1003− :: SListI bys
725+renderGroupByClause = \case
1004− => NP (By from) bys
726+ NoGroups -> ""
1005− -> GroupByClause ('Grouped bys) from
727+ Group Nil -> ""
1006−group bys = UnsafeGroupByClause $ case bys of
728+ 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.
730-- | A `HavingClause` is used to eliminate groups that are not of interest.
1011-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
731-- An `Ungrouped` `TableExpression` may only use `NoHaving` while a `Grouped`
1012-- `TableExpression` must use `Having` whose conditions are combined with
732-- `TableExpression` must use `Having` whose conditions are combined with
1013-- `.&&`.
733-- `.&&`.
1014−data HavingClause outer commons grp schemas params from where
734+data HavingClause tables grouping params where
1015− NoHaving :: HavingClause outer commons 'Ungrouped schemas params from
735+ NoHaving :: HavingClause tables 'Ungrouped params
1017− :: [Condition outer commons ('Grouped bys) schemas params from]
737+ :: [Condition tables ('Grouped bys) params]
1018− -> HavingClause outer commons ('Grouped bys) schemas params from
738+ -> HavingClause tables ('Grouped bys) params
1019−deriving instance Show (HavingClause outer commons grp schemas params from)
739+deriving instance Show (HavingClause tables grouping params)
1020−deriving instance Eq (HavingClause outer commons grp schemas params from)
740+deriving instance Eq (HavingClause tables grouping params)
1021−deriving instance Ord (HavingClause outer commons grp schemas params from)
741+deriving instance Ord (HavingClause tables grouping params)
1023-- | Render a `HavingClause`.
743-- | Render a `HavingClause`.
1024−instance RenderSQL (HavingClause outer commons grp schemas params from) where
744+renderHavingClause :: HavingClause tables grouping params -> ByteString
1025− renderSQL = \case
745+renderHavingClause = \case
1026− NoHaving -> ""
746+ NoHaving -> ""
1027− Having [] -> ""
747+ Having [] -> ""
1028− Having conditions ->
748+ Having conditions ->
1029− " HAVING" <+> commaSeparated (renderSQL <$> conditions)
749+ " HAVING" <+> commaSeparated (renderExpression <$> 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−{- |
751+{-----------------------------------------
1076−>>> import Data.Monoid (Sum (..))
752+Sorting
1077−>>> import Data.Int (Int64)
753+-----------------------------------------}
1079− let
755+-- | `SortExpression`s are used by `sortBy` to optionally sort the results
1080− query :: Query_ schema () (Sum Int64)
756+-- of a `Query`. `Asc` or `Desc` set the sort direction of a `NotNull` result
1081− query = withRecursive
757+-- column to ascending or descending. Ascending order puts smaller values
1082− ( values_ ((1 & astype int) `as` #n)
758+-- first, where "smaller" is defined in terms of the `.<` operator. Similarly,
1083− `unionAll`
759+-- descending order is determined with the `.>` operator. `AscNullsFirst`,
1084− select_ ((#n + 1) `as` #n)
760+-- `AscNullsLast`, `DescNullsFirst` and `DescNullsLast` options are used to
1085− (from (common #t) & where_ (#n .< 100)) `as` #t )
761+-- 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))
762+-- ordering of a `Null` result column.
1087− in printSQL query
763+data SortExpression tables 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"
765+ :: Expression tables grouping params ('NotNull ty)
1090−-}
766+ -> SortExpression tables grouping params
1091−withRecursive
767+ Desc
1092− :: Aliased (Query outer (recursive ': commons) schemas params) recursive
768+ :: Expression tables grouping params ('NotNull ty)
1093− -> Query outer (recursive ': commons) schemas params row
769+ -> SortExpression tables grouping params
1094− -> Query outer commons schemas params row
770+ AscNullsFirst
1095−withRecursive (recursive `As` cte) query = UnsafeQuery $
771+ :: Expression tables grouping params ('Null ty)
1096− "WITH RECURSIVE" <+> renderSQL cte
772+ -> SortExpression tables grouping params
1097− <+> "AS" <+> parenthesized (renderSQL recursive)
773+ AscNullsLast
1098− <+> renderSQL query
774+ :: Expression tables grouping params ('Null ty)
775+ -> SortExpression tables grouping params
777+ :: Expression tables grouping params ('Null ty)
778+ -> SortExpression tables grouping params
780+ :: Expression tables grouping params ('Null ty)
781+ -> SortExpression tables grouping params
782+deriving instance Show (SortExpression tables grouping params)
784+-- | Render a `SortExpression`.
785+renderSortExpression :: SortExpression tables grouping params -> ByteString
786+renderSortExpression = \case
787+ Asc expression -> renderExpression expression <+> "ASC"
788+ Desc expression -> renderExpression expression <+> "DESC"
789+ AscNullsFirst expression -> renderExpression expression
790+ <+> "ASC NULLS FIRST"
791+ DescNullsFirst expression -> renderExpression expression
792+ <+> "DESC NULLS FIRST"
793+ AscNullsLast expression -> renderExpression expression <+> "ASC NULLS LAST"
794+ DescNullsLast expression -> renderExpression expression <+> "DESC NULLS LAST"