postgresql: enum and character varying, updating

Question

I have the ENUM type in postgresql

CREATE TYPE user_state AS ENUM (\'unconfirmed\', \'locked\', \'active\');
<         


        

Answer 1

Alternatively you may register equal operator instead of define cast one. I did it for Java + MyBatis in similar situation:

CREATE FUNCTION type_user_state_with_text_equals(_a user_state, _b text)
    RETURNS boolean AS
    $func$
        SELECT _a = _b::user_state;
    $func$
    LANGUAGE SQL IMMUTABLE STRICT;

CREATE OPERATOR = (
    leftarg = user_state,
    rightarg = text,
    procedure = type_user_state_with_text_equals,
    COMMUTATOR = =,
    NEGATOR = !=,
    HASHES, MERGES
);

You may read about postgres user-defined operations in documentation and do not forget look at optimization hints.