-- adds the created or updated date tags

CREATE OR REPLACE FUNCTION set_date()
RETURNS TRIGGER AS
$$
BEGIN
    IF TG_OP = 'INSERT' THEN
        NEW.date_created := 'now';
    ELSIF TG_OP = 'UPDATE' THEN
        NEW.date_updated := 'now';
    END IF;
    RETURN NEW;
END;
$$
LANGUAGE 'plpgsql';