触发器 修改一个表的记录另一个表的相应记录也修改

[Crystal1981]

如主表A，字段：ID，NAME，ADDRESS；另一表B，结构同A，其记录为表A的部分记录。
修改表A的一条记录后，如果表B也有此条记录，则表B的此条记录也跟着修改。
请问怎么写触发器

[vivianfdlpw]

create trigger tr
on A
for update
as
if exists(select 1 from B join inserted I on I.ID=B.ID)
begin
update B
set name=I.name,
address=I.address
from B
join inserted I on I.id=B.id
end
go

[netcoder]

create trigger t_test on 表A

for insert,update,delete
delete 表B
where id in(select id from deleted)
insert into 表B
select * from inserted

[zlp321002]

--给你一个例子:
create table t_a(id int identity(1,1),username varchar(20))

create table t_b(id int identity(1,1),username varchar(20))

create trigger tr_a on t_a
for update,insert,delete
as
alter table t_b DISABLE TRIGGER tr_b
----------------------------------
if not exists (select * from deleted) --插入
insert t_b(username) select username from inserted
else if not exists (select * from inserted)--删除
delete t_b where id in (select id from deleted)
else--更新
update a set a.username=i.username from t_b as a,inserted as i where a.id=i.id
alter table t_b ENABLE TRIGGER tr_b

------------------------------------------
create trigger tr_b on t_b
for update,insert,delete
as
alter table t_a DISABLE TRIGGER tr_a
----------------------------------
if not exists (select * from deleted) --插入
insert t_a(username) select username from inserted
else if not exists (select * from inserted) --删除
delete t_a where id in (select id from deleted)
else --更新
update a set a.username=i.username from t_a as a,inserted as i where a.id=i.id
alter table t_a ENABLE TRIGGER tr_a


select * from t_a
select * from t_b

--测试：
insert t_a(username) values('test')
insert t_b(username) values('test2')
update t_a set username='test1' where id=1
update t_b set username='test3' where id=1
delete from t_a where id=1
delete from t_b where id=2
--------------------------
select * from t_a
select * from t_b

[Crystal1981]

请你讲一讲select 1 from B join inserted I on I.ID=B.ID这一句的意思，好吗？

[Crystal1981]

非常感谢各位！
现在我还有表C，D，不确定的表个数，他们都同表B一样，怎么处理呢？

[MorningTea]

B join inserted I on I.ID=B.ID---就是插入A的纪录在B也存在I.ID=B.ID的话，select 1就会有资料，否则为null罗

[Crystal1981]

有没有办法把这些表一起处理啊

[MorningTea]

你写个触发器不就一起处理了吗？！

要不用外键，可是维护起来麻烦，还是不要用！

[Crystal1981]

现在我还有表C，D....不确定的表个数，他们都同表B一样，怎么处理呢？
怎样把这些表一起处理啊！