标签:
create procedure BuyFriut @Uid varchar(50), @Fcode varchar(50), @Sl int as begin declare @kc int,@price float select @kc=Numbers,@price=Price from Fruit where Ids=@Fcode if @Sl>@kc begin print ‘库存不足!‘ end else begin declare @ye float select @ye=Account from Login where UserName=@Uid if @ye>= @price*@Sl begin update Fruit set Numbers=Numbers-@Sl where Ids=@Fcode update Login set Account=Account-@price*@Sl where UserName=@Uid declare @sj int set @sj = cast(rand()*10000 as int) insert into Orders values(@sj,@Uid,GETDATE()) insert into OrderDetails values(@sj,@Fcode,@Sl) end else begin print ‘余额不足!‘ end end end
go --使用存储过程 declare @s int exec @s = BuyFriut ‘wangwu‘,‘k001‘,20 print @s
--删除存储过程 drop proc BuyFriut
--触发器,特殊的存储过程,执行的时间和存储过程不一样,存储过程在调用的时候执行,触发器是在执行某种操作的时候触发执行,相当于C#里面的事件
--inserted表和deleted表,临时表,作用是为了恢复数据
select * from Loginone select * from biandong go --创建触发器 create trigger TR_LOGINONE_DELETE on Loginone for delete --删除的时候执行 --after delete --删除之后执行 --instead of delete --替代执行
as begin declare @uid varchar(50),@name varchar(50) select @uid=UserName,@name=Name from deleted insert into biandong values(@uid,@name,‘删除‘) end go --在对表loginnoe进行删除的时候触发器执行 delete from Loginone where UserName=‘aaa‘
go --instead of触发器 --删除student里面的数据的时候用另外两条语句替代,先删从表再删主表
create trigger TR_STUDENT_DELETE on Student instead of delete as begin declare @sno varchar(20) select @sno=sno from deleted delete from score where sno=@sno delete from student where sno=@sno end --执行删除的时候触发 delete from student where sno=‘101‘ select * from student select * from score select * from course select * from teacher
标签:
原文地址:http://www.cnblogs.com/hansonglin/p/4693192.html