Opaleye.Internal.Join

Documentation

newtype NullMaker a b

Constructors

NullMaker (a -> b)

Instances

ProductProfunctor NullMaker

Defined in Opaleye.Internal.Join

Methods

purePP :: b -> NullMaker a b

(****) :: NullMaker a (b -> c) -> NullMaker a b -> NullMaker a c

empty :: NullMaker () ()

(***!) :: NullMaker a b -> NullMaker a' b' -> NullMaker (a, a') (b, b')

Profunctor NullMaker

Defined in Opaleye.Internal.Join

Methods

dimap :: (a -> b) -> (c -> d) -> NullMaker b c -> NullMaker a d

lmap :: (a -> b) -> NullMaker b c -> NullMaker a c

rmap :: (b -> c) -> NullMaker a b -> NullMaker a c

(#.) :: forall a b c q. Coercible c b => q b c -> NullMaker a b -> NullMaker a c

(.#) :: forall a b c q. Coercible b a => NullMaker b c -> q a b -> NullMaker a c

Default NullMaker (Field a) (FieldNullable a)

Defined in Opaleye.Internal.Join

Methods

def :: NullMaker (Field a) (FieldNullable a)

Default NullMaker (FieldNullable a) (FieldNullable a)

Defined in Opaleye.Internal.Join

Methods

def :: NullMaker (FieldNullable a) (FieldNullable a)

Applicative (NullMaker a)

Defined in Opaleye.Internal.Join

Methods

pure :: a0 -> NullMaker a a0

(<*>) :: NullMaker a (a0 -> b) -> NullMaker a a0 -> NullMaker a b

liftA2 :: (a0 -> b -> c) -> NullMaker a a0 -> NullMaker a b -> NullMaker a c

(*>) :: NullMaker a a0 -> NullMaker a b -> NullMaker a b

(<*) :: NullMaker a a0 -> NullMaker a b -> NullMaker a a0

Functor (NullMaker a)

Defined in Opaleye.Internal.Join

Methods

fmap :: (a0 -> b) -> NullMaker a a0 -> NullMaker a b

(<$) :: a0 -> NullMaker a b -> NullMaker a a0

toNullable :: NullMaker a b -> a -> b

joinExplicit :: Unpackspec columnsA columnsA -> Unpackspec columnsB columnsB -> (columnsA -> returnedColumnsA) -> (columnsB -> returnedColumnsB) -> JoinType -> Query columnsA -> Query columnsB -> ((columnsA, columnsB) -> Field PGBool) -> Query (returnedColumnsA, returnedColumnsB)

leftJoinAExplicit :: Unpackspec a a -> NullMaker a nullableA -> Query a -> QueryArr (a -> Field PGBool) nullableA

optionalRestrict :: Default Unpackspec a a => Select a -> SelectArr (a -> Field SqlBool) (MaybeFields a)

optionalRestrictExplicit :: Unpackspec a a -> Select a -> SelectArr (a -> Field SqlBool) (MaybeFields a)

leftJoinInTermsOfOptionalRestrict :: Default Unpackspec fieldsR fieldsR => Select fieldsL -> Select fieldsR -> ((fieldsL, fieldsR) -> Field SqlBool) -> Select (fieldsL, MaybeFields fieldsR)

An example to demonstrate how the functionality of LEFT JOIN can be recovered using optionalRestrict.

extractLeftJoinFields :: Int -> Tag -> PrimExpr -> PM [(Symbol, PrimExpr)] PrimExpr