菜鸟问题（sql触发器）
两个表A，B
B表中的y列的值都是从A表中x列里取的   我想让A.x的值变化时对应的B.y的那些值跟着变化。如何写？谢谢


------解决方案--------------------
create trigger tri_test on a
for update
as
if update(x)
update b set y=a.x from inserted a where a.id=b.id
------解决方案--------------------
create trigger Update_b on a
for update ,insert ,delete
as
begin
if not exists(select 1 from deleted)--a表进行insert操作
insert into b(y) select x from inserted

if not exists(select 1 from inserted)--a表进行delete操作
delete from b where y in (select x from deleted)

if exists(select 1 from inserted) and exists(select 1 from deleted)--a表进行update操作
update b set b.y=i.x from b,inserted i,deleted d
where b.y=d.y
end
------解决方案--------------------
--两个表A，B
--B表中的y列的值都是从A表中x列里取的 我想让A.x的值变化时对应的B.y的那些值跟着变化。如何写？谢谢
create table a
(
uid int,
uname varchar(50)
)
insert into a values(1, 'taiji ')
insert into a values(2, 'baguai ')
insert into a values(3, 'tianlong ')
insert into a values(4, 'cao ')
insert into a values(5, 'ddd ')
insert into a values(6, 'yun ')
insert into a values(7, 'lijdjjie ')
select * from a

drop table a

create table b
(
bid int identity,
uname varchar(50)
)

insert into b(uname) select uname from a

create trigger DoOne
on a for update
as
update b set uname = (select uname from inserted ) where uname=(select uname from deleted)

drop trigger DoOne

update a set uname = 'aaa ' where uid=1