src/Rel8/Query/Set.hs · rel8

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1{-# language FlexibleContexts #-}

3module Rel8.Query.Set

4 ( union, unionAll

5 , intersect, intersectAll

6 , except, exceptAll

7 )

8where

10-- base

11import Prelude ()

13-- opaleye

14import qualified Opaleye.Binary as Opaleye

16-- rel8

17import Rel8.Expr ( Expr )

18import {-# SOURCE #-} Rel8.Query ( Query )

19import Rel8.Query.Opaleye ( zipOpaleyeWith )

20import Rel8.Table ( Table )

21import Rel8.Table.Eq ( EqTable )

22import Rel8.Table.Opaleye ( binaryspec )

25-- | Combine the results of two queries of the same type, collapsing

26-- duplicates. @union a b@ is the same as the SQL statement @x UNION b@.

27union :: EqTable a => Query a -> Query a -> Query a

28union = zipOpaleyeWith (Opaleye.unionExplicit binaryspec)

31-- | Combine the results of two queries of the same type, retaining duplicates.

32-- @unionAll a b@ is the same as the SQL statement @x UNION ALL b@.

33unionAll :: Table Expr a => Query a -> Query a -> Query a

34unionAll = zipOpaleyeWith (Opaleye.unionAllExplicit binaryspec)

37-- | Find the intersection of two queries, collapsing duplicates. @intersect a

38-- b@ is the same as the SQL statement @x INTERSECT b@.

39intersect :: EqTable a => Query a -> Query a -> Query a

40intersect = zipOpaleyeWith (Opaleye.intersectExplicit binaryspec)

43-- | Find the intersection of two queries, retaining duplicates. @intersectAll

44-- a b@ is the same as the SQL statement @x INTERSECT ALL b@.

45intersectAll :: EqTable a => Query a -> Query a -> Query a

46intersectAll = zipOpaleyeWith (Opaleye.intersectAllExplicit binaryspec)

49-- | Find the difference of two queries, collapsing duplicates @except a b@ is

50-- the same as the SQL statement @x INTERSECT b@.

51except :: EqTable a => Query a -> Query a -> Query a

52except = zipOpaleyeWith (Opaleye.exceptExplicit binaryspec)

55-- | Find the difference of two queries, retaining duplicates. @exceptAll a b@

56-- is the same as the SQL statement @x EXCEPT ALL b@.

57exceptAll :: EqTable a => Query a -> Query a -> Query a

58exceptAll = zipOpaleyeWith (Opaleye.exceptAllExplicit binaryspec)