| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Database.Beam.Backend.Types
Synopsis
-
class
BeamBackend
be
where
- type BackendFromField be :: Type -> Constraint
- data Exposed x
- data Nullable (c :: Type -> Type ) x
Documentation
class BeamBackend be Source #
Class for all Beam backends
Associated Types
type BackendFromField be :: Type -> Constraint Source #
Requirements to marshal a certain type from a database of a particular backend
Instances
| BeamBackend ( MockSqlBackend syntax) Source # | |
|
Defined in Database.Beam.Backend.SQL Associated Types type BackendFromField ( MockSqlBackend syntax) :: Type -> Constraint Source # |
|
newtype mainly used to inspect the tag structure of a particular
Beamable
. Prevents overlapping instances in some case. Usually not used
in end-user code.
Instances
| FieldsFulfillConstraintNullable c t => GFieldsFulfillConstraint c ( K1 R (t ( Nullable Exposed )) :: Type -> Type ) ( K1 R (t ( Nullable ( HasConstraint c))) :: Type -> Type ) Source # | |
|
Defined in Database.Beam.Schema.Tables |
|
| FieldsFulfillConstraint c t => GFieldsFulfillConstraint c ( K1 R (t Exposed ) :: Type -> Type ) ( K1 R (t ( HasConstraint c)) :: Type -> Type ) Source # | |
|
Defined in Database.Beam.Schema.Tables |
|
| c x => GFieldsFulfillConstraint c ( K1 R ( Exposed x) :: Type -> Type ) ( K1 R ( HasConstraint c x) :: Type -> Type ) Source # | |
|
Defined in Database.Beam.Schema.Tables |
|
data Nullable (c :: Type -> Type ) x Source #
Support for NULLable Foreign Key references.
data MyTable f = MyTable
{ nullableRef :: PrimaryKey AnotherTable (Nullable f)
, ... }
deriving (Generic, Typeable)
See
Columnar
for more information.