CREATE OR REPLACE FUNCTION packagelisting_statuschange() RETURNS trigger AS $packagelisting_statuschange$
    BEGIN
        -- Check that the status changed --
        IF NEW.statuscode IS DISTINCT FROM OLD.statuscode THEN
            NEW.statuschange := current_timestamp;
        END IF;

        RETURN NEW;
    END;
$packagelisting_statuschange$ LANGUAGE plpgsql;

CREATE TRIGGER packagelisting_statuschange BEFORE INSERT OR UPDATE ON packagelisting
    FOR EACH ROW EXECUTE PROCEDURE packagelisting_statuschange() ;