src/Rel8/Statement/View.hs · rel8

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1{-# language FlexibleContexts #-}

2{-# language MonoLocalBinds #-}

4module Rel8.Statement.View

5 ( createView

6 )

7where

9-- base

10import Prelude

12-- hasql

13import qualified Hasql.Decoders as Hasql

14import qualified Hasql.Encoders as Hasql

15import qualified Hasql.Statement as Hasql

17-- rel8

18import Rel8.Query ( Query )

19import Rel8.Schema.Name ( Selects )

20import Rel8.Schema.Table ( TableSchema )

21import Rel8.Statement.Insert ( ppInto )

22import Rel8.Statement.Select ( ppSelect )

24-- pretty

25import Text.PrettyPrint ( Doc, (<+>), ($$), text )

27-- text

28import qualified Data.Text as Text

29import Data.Text.Encoding ( encodeUtf8 )

32-- | Given a 'TableSchema' and 'Query', @createView@ runs a @CREATE VIEW@

33-- statement that will save the given query as a view. This can be useful if

34-- you want to share Rel8 queries with other applications.

35createView :: Selects names exprs

36 => TableSchema names -> Query exprs -> Hasql.Statement () ()

37createView schema query = Hasql.Statement bytes params decode prepare

38 where

39 bytes = encodeUtf8 (Text.pack sql)

40 params = Hasql.noParams

41 decode = Hasql.noResult

42 prepare = False

43 sql = show doc

44 doc = ppCreateView schema query

47ppCreateView :: Selects names exprs

48 => TableSchema names -> Query exprs -> Doc

49ppCreateView schema query =

50 text "CREATE VIEW" <+>

51 ppInto schema $$

52 text "AS" <+>

53 ppSelect query