CREATE OR REPLACE FUNCTION demographic( demographic_type varchar, demographic_code varchar, demographic_description varchar)
 RETURNS TABLE (demographic_type_id uuid, demographic_value_id uuid ) AS $$

DECLARE
        demographic_type_id uuid;
        demographic_value_id uuid;
BEGIN

    SELECT id INTO demographic_type_id FROM demographic WHERE lower(name) = lower(demographic_type);
        IF NOT FOUND THEN
                BEGIN
                        INSERT INTO demographic (id, name) VALUES (uuid_generate_v4(), demographic_type) RETURNING id INTO demographic_type_id;
            EXCEPTION WHEN unique_violation THEN
                        SELECT id INTO demographic_type_id FROM demographic WHERE lower(name) = lower(demographic_type);
                END;
        END IF;

        SELECT id INTO demographic_value_id FROM demographic_value WHERE demographic_id = demographic_type_id AND code = demographic_code;
        IF NOT FOUND THEN
                BEGIN
                        INSERT INTO demographic_value (id, demographic_id, code, description) VALUES (uuid_generate_v4(), demographic_type_id, demographic_code, demographic_description) RETURNING id INTO demographic_value_id;
                EXCEPTION WHEN unique_violation THEN
                        SELECT id INTO demographic_value_id FROM demographic_value WHERE demographic_id = demographic_type_id AND code = demographic_code;
                END;
        END IF;

        RETURN QUERY SELECT demographic_type_id, demographic_value_id;
END;
$$ LANGUAGE plpgsql;