Функция plpgsql с циклом по таблице change_request

CREATE FUNCTION update_users() RETURNS text AS $$
DECLARE
    i    RECORD;
BEGIN
    FOR i IN SELECT * FROM change_request ORDER BY id LOOP
        UPDATE users SET email = i.email, age = i.age WHERE id = i.user_id;
    END LOOP;
    RETURN 'OK';
END;
$$ LANGUAGE plpgsql;

SELECT update_users();

drop FUNCTION update_users();