创建一个触发器
语法:
create trigger 触发器名字
create trigger xiaoshou_update_trigger after update on xiaoshou for each row begin update jiangjin set xiaoshouer=( select sum(taoshu*danjia)from xiaoshou where userid=new.userid and month=new.month) , jiangjin=(select sum(taoshu*xiaoshou.danjia*ticheng) from house,xiaoshou where userid=new.userid and month=new.month and houseid=id) where userid=new.userid and month=new.month;delete from jiangjin where xiaoshouer<500; delete from jiangjin where xiaoshouer<500; end
原文:http://sunsai.blog.51cto.com/9044695/1426487