Database.PostgreSQL.PQTypes.Composite

Documentation

newtype Composite a

Wrapper for (de)serializing composite types.

Constructors

Composite a

Instances

Functor Composite

Methods

fmap :: (a -> b) -> Composite a -> Composite b

(<$) :: a -> Composite b -> Composite a

Eq a => Eq (Composite a)

Methods

(==) :: Composite a -> Composite a -> Bool

(/=) :: Composite a -> Composite a -> Bool

Ord a => Ord (Composite a)

Methods

compare :: Composite a -> Composite a -> Ordering

(<) :: Composite a -> Composite a -> Bool

(<=) :: Composite a -> Composite a -> Bool

(>) :: Composite a -> Composite a -> Bool

(>=) :: Composite a -> Composite a -> Bool

max :: Composite a -> Composite a -> Composite a

min :: Composite a -> Composite a -> Composite a

Show a => Show (Composite a)

Methods

showsPrec :: Int -> Composite a -> ShowS

show :: Composite a -> String

showList :: [Composite a] -> ShowS

PQFormat t => PQFormat (Composite t)

Methods

pqFormat :: Composite t -> ByteString

pqFormat0 :: Composite t -> ByteString

pqVariables :: Composite t -> Int

CompositeFromSQL t => FromSQL (Composite t)

Associated Types

type PQBase (Composite t) :: *

Methods

fromSQL :: Maybe (PQBase (Composite t)) -> IO (Composite t)

CompositeToSQL t => ToSQL (Composite t)

Associated Types

type PQDest (Composite t) :: *

Methods

toSQL :: Composite t -> ParamAllocator -> (Ptr (PQDest (Composite t)) -> IO r) -> IO r

type PQBase (Composite t)

type PQBase (Composite t) = Ptr PGresult

type PQDest (Composite t)

type PQDest (Composite t) = PGparam

unComposite :: Composite a -> a

Extract underlying value.

type family CompositeRow t :: *

Type function which maps composite type to its intermediate representation as a tuple (row) of Haskell types that correspond to PostgreSQL types in composite type definition.

As an example, consider the type defined as (a INTEGER, b DATE). Then its CompositeRow instance could be (Maybe Int32, Maybe Day), (Maybe Int32, Day), (Int32, Maybe Day) or (Int32, Day).

class (PQFormat t, FromRow (CompositeRow t)) => CompositeFromSQL t where

Class which represents "from SQL to composite" transformation.

Minimal complete definition

toComposite

Methods

toComposite :: CompositeRow t -> t

Convert composite row to destination type.

class (PQFormat t, ToRow (CompositeRow t)) => CompositeToSQL t where

Class which represents "from composite to SQL" transformation.

Minimal complete definition

fromComposite

Methods

fromComposite :: t -> CompositeRow t

Convert composite type to its intermediate representation.