1 CREATE OR REPLACE FUNCTION sms_credits() RETURNS trigger
4 IF NEW.cost <> OLD.cost
6 UPDATE clickatell SET credits = credits + OLD.cost - NEW.cost;
10 $_X$ LANGUAGE plpgsql;
13 ALTER TABLE clickatell ADD COLUMN credits NUMERIC NOT NULL DEFAULT 0.0;
14 CREATE TRIGGER sms_credits AFTER UPDATE OF cost ON sms FOR EACH ROW WHEN (NEW.cost <> OLD.cost) EXECUTE PROCEDURE sms_credits();