Added support for converting PGInt4 to Int32

(This is first part of tomjaguarpaw#110.)

Author: duairc

src/Opaleye/Constant.hs

@@ -54,6 +54,9 @@ instance D.Default Constant LT.Text (Column T.PGText) where
 instance D.Default Constant Int (Column T.PGInt4) where
   def = Constant T.pgInt4
 
+instance D.Default Constant Int.Int32 (Column T.PGInt4) where
+  def = Constant $ T.pgInt4 . fromIntegral
+
 instance D.Default Constant Int.Int64 (Column T.PGInt8) where
   def = Constant T.pgInt8
 

src/Opaleye/Internal/RunQuery.hs

@@ -33,7 +33,7 @@ import qualified Data.ByteString.Lazy as LBS
 import qualified Data.Time as Time
 import qualified Data.String as String
 import           Data.UUID (UUID)
-import           GHC.Int (Int64)
+import           GHC.Int (Int32, Int64)
 
 -- { Only needed for annoying postgresql-simple patch below
 
@@ -125,6 +125,9 @@ class QueryRunnerColumnDefault pgType haskellType where
 instance QueryRunnerColumnDefault T.PGInt4 Int where
   queryRunnerColumnDefault = fieldQueryRunnerColumn
 
+instance QueryRunnerColumnDefault T.PGInt4 Int32 where
+  queryRunnerColumnDefault = fieldQueryRunnerColumn
+
 instance QueryRunnerColumnDefault T.PGInt8 Int64 where
   queryRunnerColumnDefault = fieldQueryRunnerColumn