mysql之触发器的简单应用

mysql之触发器的简单应用

例子1：添加时触发表操作

CREATE TRIGGER `updateitemnum` AFTER INSERT ON `in_import`
FOR EACH ROW if  new.import_item_status=1 then
update in_item set item_num=item_num+new.import_item_num where item_id=new.import_item_id;
elseif  new.import_item_status=2 then
update in_item set item_num=item_num-new.import_item_num where item_id=new.import_item_id;
end if

例子2：删除时触发表操作

CREATE TRIGGER `deleteorderdetail` BEFORE DELETE ON `in_order_master`
FOR EACH ROW BEGIN
DELETE FROM in_order_detail WHERE order_sn=old.order_sn;
DELETE FROM in_import WHERE order_sn=old.order_sn;
END