postgresql触发器

CREATE OR REPLACE FUNCTION cd03.f_repair_order_stat_update()
 RETURNS trigger
 LANGUAGE plpgsql
AS $function$
/*-------------------------------------------------------
* 功能：触发器函数,当stat被更新时                       *
* 参数：无                                              *
* 作者：jayzhou                                         *
* 版本：v1.0                                            *
* 日期：2015.6.30                                       *
*-------------------------------------------------------*/
BEGIN
    --触发条件判断
    IF (TG_OP='UPDATE') THEN
        insert into repair_process select NEW.no,NEW.stat;
    END IF;
         RETURN NEW;
END;
$function$;

CREATE TRIGGER t_repair_order_stat
AFTER UPDATE ON repair_order
    FOR EACH ROW WHEN (OLD.stat<>NEW.stat) EXECUTE PROCEDURE f_repair_order_stat_update();
    
CREATE TRIGGER t_repair_order_no    
BEFORE INSERT ON repair_order 
        FOR EACH ROW EXECUTE PROCEDURE f_orders_no_create();