| Copyright | 2015 Dylan Simon |
|---|---|
| Safe Haskell | None |
| Language | Haskell98 |
Database.PostgreSQL.Typed.Enum
Description
Support for PostgreSQL enums.
Documentation
class (Eq a, Ord a, Enum a, Bounded a, Show a) => PGEnum a Source #
A type based on a PostgreSQL enum. Automatically instantiated by makePGEnum.
pgEnumValues :: PGEnum a => [(a, String)] Source #
List of all the values in the enum along with their database names.
Arguments
| :: String | PostgreSQL enum type name |
| -> String | Haskell type to create |
| -> (String -> String) | How to generate constructor names from enum values, e.g. |
| -> DecsQ |
Create a new enum type corresponding to the given PostgreSQL enum type.
For example, if you have CREATE TYPE foo AS ENUM ('abc', 'DEF');, then
makePGEnum "foo" "Foo" ("Foo_"++) will be equivalent to:
data Foo = Foo_abc | Foo_DEF deriving (Eq, Ord, Enum, Bounded, Typeable) instance Show Foo where show Foo_abc = "abc" ... instance PGType "foo" instance PGParameter "foo" Foo where ... instance PGColumn "foo" Foo where ... instance PGRep "foo" Foo instance PGEnum Foo where pgEnumValues = [(Foo_abc, "abc"), (Foo_DEF, "DEF")]
Requires language extensions: TemplateHaskell, FlexibleInstances, MultiParamTypeClasses, DeriveDataTypeable, DataKinds