CREATE OR REPLACE FUNCTION site_aggregates_site ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
IF (TG_OP = 'INSERT') THEN
INSERT INTO site_aggregates (site_id)
VALUES (NEW.id);
ELSIF (TG_OP = 'DELETE') THEN
DELETE FROM site_aggregates
WHERE site_id = OLD.id;
END IF;
RETURN NULL;
END
$$;