Safe Haskell	None
Language	Haskell2010

Opaleye.Distinct

Contents

Explicit versions
Adaptors

Synopsis

distinct :: Default Distinctspec fields fields => Select fields -> Select fields
data Distinctspec a b
distinctExplicit :: Distinctspec fields fields' -> Select fields -> Select fields'
distinctspecField :: Distinctspec (Column a) (Column a)
distinctspecMaybeFields :: WithNulls Distinctspec a b -> Distinctspec (MaybeFields a) (MaybeFields b)

Documentation

distinct :: Default Distinctspec fields fields => Select fields -> Select fields Source #

Remove duplicate rows from the Select.

Example type specialization:

distinct :: Select (Field a, Field b) -> Select (Field a, Field b)

Assuming the makeAdaptorAndInstance splice has been run for the product type Foo:

distinct :: Select (Foo (Field a) (Field b) (Field c)) -> Select (Foo (Field a) (Field b) (Field c))

If you want to run distinct on SelectArrs you should apply laterally to it:

laterally distinct :: Default Distinctspec fields fields => SelectArr i fields -> SelectArr i fields

data Distinctspec a b Source #

Instances

Instances details

Profunctor Distinctspec Source #
Instance details Defined in Opaleye.Internal.Distinct Methods dimap :: (a -> b) -> (c -> d) -> Distinctspec b c -> Distinctspec a d # lmap :: (a -> b) -> Distinctspec b c -> Distinctspec a c # rmap :: (b -> c) -> Distinctspec a b -> Distinctspec a c # (#.) :: forall a b c q. Coercible c b => q b c -> Distinctspec a b -> Distinctspec a c # (.#) :: forall a b c q. Coercible b a => Distinctspec b c -> q a b -> Distinctspec a c #
ProductProfunctor Distinctspec Source #
Instance details Defined in Opaleye.Internal.Distinct Methods purePP :: b -> Distinctspec a b # (**) :: Distinctspec a (b -> c) -> Distinctspec a b -> Distinctspec a c # empty :: Distinctspec () () # (*!) :: Distinctspec a b -> Distinctspec a' b' -> Distinctspec (a, a') (b, b') #
SumProfunctor Distinctspec Source #
Instance details Defined in Opaleye.Internal.Distinct Methods (+++!) :: Distinctspec a b -> Distinctspec a' b' -> Distinctspec (Either a a') (Either b b') #
Default Distinctspec (Column a) (Column a) Source #
Instance details Defined in Opaleye.Internal.Distinct Methods def :: Distinctspec (Column a) (Column a) #
Default (WithNulls Distinctspec) a b => Default Distinctspec (MaybeFields a) (MaybeFields b) Source #
Instance details Defined in Opaleye.Internal.Distinct Methods def :: Distinctspec (MaybeFields a) (MaybeFields b) #
Functor (Distinctspec a) Source #
Instance details Defined in Opaleye.Internal.Distinct Methods fmap :: (a0 -> b) -> Distinctspec a a0 -> Distinctspec a b # (<$) :: a0 -> Distinctspec a b -> Distinctspec a a0 #
Applicative (Distinctspec a) Source #
Instance details Defined in Opaleye.Internal.Distinct Methods pure :: a0 -> Distinctspec a a0 # (<>) :: Distinctspec a (a0 -> b) -> Distinctspec a a0 -> Distinctspec a b # liftA2 :: (a0 -> b -> c) -> Distinctspec a a0 -> Distinctspec a b -> Distinctspec a c # (>) :: Distinctspec a a0 -> Distinctspec a b -> Distinctspec a b # (<*) :: Distinctspec a a0 -> Distinctspec a b -> Distinctspec a a0 #

Explicit versions

distinctExplicit :: Distinctspec fields fields' -> Select fields -> Select fields' Source #

Adaptors

distinctspecField :: Distinctspec (Column a) (Column a) Source #

distinctspecMaybeFields :: WithNulls Distinctspec a b -> Distinctspec (MaybeFields a) (MaybeFields b) Source #