Defining a PostgreSQL enum type

color.sql

--
-- Create user-defined enum type.
-- (List details with '\dT+ color' in psql)
--
CREATE TYPE color AS ENUM ('RED', 'GREEN', 'BLUE');

--
-- Create a table using the user-defined enum type.
--
CREATE TABLE quark (
  color color not null
);

--
-- Insert a value into the table
--
INSERT INTO quark(color) values ('RED'::color);