151df34 · squeal · git.iko.soy

git.iko.soy/squeal

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Merge pull request #126 from morphismtech/dev-with-recursive2

151df34Eitan Chatav8 years ago

squeal-postgresql/src/Squeal/PostgreSQL/Alias.hs+8

compare with dev

unifiedsplit

@@ -40,6 +40,7 @@ module Squeal.PostgreSQL.Alias

40 , Aliased (As)

41 , Aliasable (as)

42 , renderAliased

43+ , RenderFields (..)

43 , Has

44 , Has

44 , HasUnique

45 , HasUnique

45 , HasAll

46 , HasAll

@@ -166,6 +167,13 @@ renderAliased

166renderAliased render (expression `As` alias) =

167renderAliased render (expression `As` alias) =

167 render expression <> " AS " <> renderSQL alias

168 render expression <> " AS " <> renderSQL alias

168

169

170+class RenderFields (row :: [(Symbol, ty)]) where

171+ renderFields :: p row -> [ByteString]

172+instance RenderFields '[] where renderFields _ = []

173+instance (KnownSymbol col, RenderFields row)

174+ => RenderFields (col ::: ty ': row) where

175+ renderFields _ = renderSQL (Alias @col) : renderFields (SOP.Proxy @row)

176+

169-- | @HasUnique alias fields field@ is a constraint that proves that

177-- | @HasUnique alias fields field@ is a constraint that proves that

170-- @fields@ is a singleton of @alias ::: field@.

178-- @fields@ is a singleton of @alias ::: field@.

171type HasUnique alias fields field = fields ~ '[alias ::: field]

179type HasUnique alias fields field = fields ~ '[alias ::: field]

squeal-postgresql/src/Squeal/PostgreSQL/Query.hs+30

@@ -53,6 +53,7 @@ module Squeal.PostgreSQL.Query

53 -- ** With

54 , With (..)

55 , CommonTableExpression (..)

56+ , withRecursive

56 -- * Table Expressions

57 -- * Table Expressions

57 , TableExpression (..)

58 , TableExpression (..)

58 , from

59 , from

@@ -965,3 +966,32 @@ instance With (Query outer) where

965 with Done query = query

966 with Done query = query

966 with ctes query = UnsafeQuery $

967 with ctes query = UnsafeQuery $

967 "WITH" <+> renderSQL ctes <+> renderSQL query

968 "WITH" <+> renderSQL ctes <+> renderSQL query

969+

970+{- |

971+>>> import Data.Monoid (Sum (..))

972+>>> import Data.Int (Int32)

973+>>> :{

974+ let

975+ one :: Expr ('NotNull 'PGint4)

976+ one = 1

977+ query :: Query_ schema () (Sum Int32)

978+ query = withRecursive

979+ ( values_ (one `as` #n)

980+ `unionAll`

981+ select_ ((#n + 1) `as` #n)

982+ (from (common #t) & where_ (#n .< 100)) `as` #t )

983+ ( select_ (sum_ (All #n) `as` #getSum) (from (common #t) & groupBy Nil))

984+ in printSQL query

985+:}

986+WITH RECURSIVE "t"("n") AS ((SELECT * FROM (VALUES (1)) AS t ("n")) UNION ALL (SELECT ("n" + 1) AS "n" FROM "t" AS "t" WHERE ("n" < 100))) SELECT sum(ALL "n") AS "getSum" FROM "t" AS "t"

987+-}

988+withRecursive

989+ :: RenderFields recursive

990+ => Aliased (Query outer (cte ::: recursive ': commons) schemas params) (cte ::: recursive)

991+ -> Query outer (cte ::: recursive ': commons) schemas params row

992+ -> Query outer commons schemas params row

993+withRecursive (recursive `As` cte) query = UnsafeQuery $

994+ "WITH RECURSIVE" <+> renderSQL cte

995+ <> parenthesized (commaSeparated (renderFields recursive))

996+ <+> "AS" <+> parenthesized (renderSQL recursive)

997+ <+> renderSQL query