Num package:rel8
Return the number of rows affected.
DBEnum contains the necessary metadata to describe a
PostgreSQL enum type.
The class of database types that support the +, *,
- operators, and the abs, negate,
sign functions.
A deriving-via helper type for column types that store an "enum" type
(in Haskell terms, a sum type where all constructors are nullary)
using a Postgres
enum type.
Note that this should map to a specific type in your database's schema
(explicitly created with
CREATE TYPE ... AS ENUM). Use
DBEnum to specify the name of this Postgres type and the names
of the individual values. If left unspecified, the names of the values
of the Postgres
enum are assumed to match exactly exactly the
names of the constructors of the Haskell type (up to and including
case sensitivity).
Types that are sum types, where each constructor is unary (that is,
has no fields).
The name of the PostgreSQL enum type that a maps to.
Map Haskell values to the corresponding element of the enum
type. The default implementation of this method will use the exact
name of the Haskell constructors.