如何用触发器在修改A表的一列后，B表的一列也更新

[eagleweng]

create table a(ac1 char(20) PRIMARY KEY, ac2 char(1),ac3 int)
create table b(bc1 char(20) PRIMARY KEY, bc2 int )
当A表中的ac2的值由0变为1的时，b表的bc2的值为：bc2= bc2 - ac3
这个触发器该怎么写？

[CrazyFor]

http://expert.csdn.net/Expert/topic/1578/1578364.xml?temp=.3419001

[yoki]

create trigger ss
on a
for update
as
update b set bc2=bc2-deleted.ac3 where deleted.ac2=1

[yoki]

漏了
create trigger ss
on a
for update
as
update b set bc2=bc2-inserted.ac3 where deleted.ac2=0 and inserted.ac2=1

[pengdali]

CREATE TRIGGER 名 ON a
FOR UPDATE
AS
update b set bc2=b.bc2-a.ac3 from inserted a where a.ac1=b.bc2 and a.ac2=1

[pengdali]

CREATE TRIGGER 名 ON a
FOR UPDATE
AS
update b set bc2=b.bc2-a.ac3 from inserted a,deleted c where a.ac1=b.bc2 and a.ac1=c.ac1 and c.ac2=0 and a.ac2=1