{-# LANGUAGE FlexibleContexts #-}
module Opaleye.RunQuery (module Opaleye.RunQuery,
IRQ.Cursor,
IRQ.FromFields,
IRQ.FromField,
QueryRunner,
IRQ.QueryRunnerColumn,
IRQ.QueryRunnerColumnDefault (..),
IRQ.fieldQueryRunnerColumn,
IRQ.fieldParserQueryRunnerColumn) where
import Control.Applicative (pure, (<$>))
import qualified Database.PostgreSQL.Simple as PGS
import qualified Database.PostgreSQL.Simple.Cursor as PGSC
import qualified Database.PostgreSQL.Simple.FromRow as FR
import qualified Data.String as String
import Opaleye.Column (Column)
import qualified Opaleye.Select as S
import qualified Opaleye.Sql as S
import Opaleye.Internal.RunQuery (QueryRunner(QueryRunner))
import qualified Opaleye.Internal.RunQuery as IRQ
import qualified Opaleye.Internal.QueryArr as Q
import qualified Data.Profunctor as P
import qualified Data.Profunctor.Product.Default as D
runQuery :: D.Default IRQ.FromFields fields haskells
=> PGS.Connection
-> S.Select fields
-> IO [haskells]
runQuery = runQueryExplicit D.def
runQueryFold
:: D.Default IRQ.FromFields fields haskells
=> PGS.Connection
-> S.Select fields
-> b
-> (b -> haskells -> IO b)
-> IO b
runQueryFold = runQueryFoldExplicit D.def
queryRunnerColumn :: (Column a' -> Column a) -> (b -> b')
-> IRQ.FromField a b -> IRQ.FromField a' b'
queryRunnerColumn colF haskellF qrc = IRQ.QueryRunnerColumn (P.lmap colF u)
(fmapFP haskellF fp)
where IRQ.QueryRunnerColumn u fp = qrc
fmapFP = fmap . fmap . fmap
runQueryExplicit :: IRQ.FromFields fields haskells
-> PGS.Connection
-> S.Select fields
-> IO [haskells]
runQueryExplicit qr conn q = maybe (return []) (PGS.queryWith_ parser conn) sql
where (sql, parser) = prepareQuery qr q
runQueryFoldExplicit
:: IRQ.FromFields fields haskells
-> PGS.Connection
-> S.Select fields
-> b
-> (b -> haskells -> IO b)
-> IO b
runQueryFoldExplicit qr conn q z f = case sql of
Nothing -> return z
Just sql' -> PGS.foldWith_ parser conn sql' z f
where (sql, parser) = prepareQuery qr q
declareCursor
:: D.Default IRQ.FromFields fields haskells
=> PGS.Connection
-> S.Select fields
-> IO (IRQ.Cursor haskells)
declareCursor = declareCursorExplicit D.def
declareCursorExplicit
:: IRQ.FromFields fields haskells
-> PGS.Connection
-> S.Select fields
-> IO (IRQ.Cursor haskells)
declareCursorExplicit qr conn q =
case mbQuery of
Nothing -> pure IRQ.EmptyCursor
Just query -> IRQ.Cursor rowParser <$> PGSC.declareCursor conn query
where
(mbQuery, rowParser) = prepareQuery qr q
closeCursor :: IRQ.Cursor fields -> IO ()
closeCursor IRQ.EmptyCursor = pure ()
closeCursor (IRQ.Cursor _ cursor) = PGSC.closeCursor cursor
foldForward
:: IRQ.Cursor haskells
-> Int
-> (a -> haskells -> IO a)
-> a
-> IO (Either a a)
foldForward IRQ.EmptyCursor _chunkSize _f z = pure $ Left z
foldForward (IRQ.Cursor rowParser cursor) chunkSize f z =
PGSC.foldForwardWithParser cursor rowParser chunkSize f z
{-# DEPRECATED prepareQuery "Will be removed in version 0.7" #-}
prepareQuery :: IRQ.FromFields fields haskells -> S.Select fields -> (Maybe PGS.Query, FR.RowParser haskells)
prepareQuery qr@(QueryRunner u _ _) q = (sql, parser)
where sql :: Maybe PGS.Query
sql = fmap String.fromString (S.showSqlForPostgresExplicit u q)
(b, _, _) = Q.runSimpleQueryArrStart q ()
parser = IRQ.prepareRowParser qr b