sqlserver级联删除

[wccwccwcw]

sqlserver怎么实现级联删除啊 求指教 最好来个通俗易懂的例子

我是弄个论坛 在删主题时报错 不能带着回复一起删掉

拜托了

[人生无悔]

on delete cascade--级联删除
on update cascade--级联更新

[koumingjie]

--级联删除
create table ta(id int not null primary key)
insert ta
select 1

create table tb(id int foreign key references ta(id) on delete cascade)
insert tb
select 1

select * from ta
select * from tb
delete ta
select * from ta
select * from tb

drop table tb
drop table ta

[开着拖拉机泡妞]

--->>>>TravyLee生成测试数据
if object_id('test')is not null
drop table test
go
create table test(
id int primary key,
value varchar(10)
)
go
insert test(id,value)
select 1,'test1' union all
select 2,'test2' union all
select 3,'test3' union all
select 4,'test4' union all
select 5,'test5'
go


if object_id('tbl')is not null
drop table tbl
go
create table tbl(
id int foreign key references test(id) 
on delete cascade --指定级联删除
on update cascade, --指定级联更新
value varchar(5)
)
go
insert tbl
select 1,'true' union all
select 2,'false' union all
select 3,'false' union all
select 4,'true' union all
select 5,'false'
go

delete from test where value='test2'


select * from test

/*
test数据
-------------------------
id	value
1	test1
3	test3
4	test4
5	test5
-------------------------
tbl数据
--------------------------
id	value
1	true
3	false
4	true
5	false
*/

[Aaron_Chan]

[Quote=引用楼主 的回复:]
sqlserver怎么实现级联删除啊 求指教 最好来个通俗易懂的例子

我是弄个论坛 在删主题时报错 不能带着回复一起删掉

拜托了
[/Quote]

楼主，如果你的数据表已经建立好了，并且，你不希望更改你的表的话，你可以用“替代触发器”。
给你个简单的例子：

create trigger tri_d
on borrow
instead of delete
declare @bookid int
select @bookid=bookid from deleted
delete from borrow where bookid=@bookid
delete from book where bookid=@bookid

当你执行：
delete from book where bookid=1时，就会删除掉borrow中bookid=1与book表中id=1的数据库

[wccwccwcw]

好的，我试试