sql server触发器用到的两个逻辑表：
deleted和inserted分别代表操作所变更的旧记录集和操作所产生的新记录集。
其中：
执行INSERT操作后deleted逻辑表为空，inserted逻辑表有数据；
执行DELETE操作后inserted逻辑表为空，deleted逻辑表有数据；
执行UPDATE操作后两个逻辑表都有数据,deleted为旧记录集，inserted为新记录集。
以上操作变更几条记录，逻辑表就会产生几条记录，多条记录可以在触发器中用游标处理。
如：
CREATE TRIGGER qf_trigger
ON User_table
for INSERT,DELETE,UPDATE
AS
BEGIN
declare @userid varchar(20)
declare rs cursor for
select userid from deleted
open rs
fetch next from rs into @userid
while @@fetch_status=0
begin
if update(用户名)
insert into old_users(userid) values (@userid)
fetch next from rs into @userid
end
close rs
deallocate rs
declare rs cursor for
select userid from inserted
open rs
fetch next from rs into @userid
while @@fetch_status=0
begin
if update(用户名)
begin
if(@userid='admin')
begin
raiserror('此用户名禁用!',10,1) with nowait
rollback
return
end
insert into new_users(userid) values (@userid)
end
fetch next from rs into @userid
end
close rs
deallocate rs
END
ON User_table
for INSERT,DELETE,UPDATE
AS
BEGIN
declare @userid varchar(20)
--保存旧值
declare rs cursor for
select userid from deleted
open rs
fetch next from rs into @userid
while @@fetch_status=0
begin
if update(用户名)
insert into old_users(userid) values (@userid)
fetch next from rs into @userid
end
close rs
deallocate rs
--保存新值
declare rs cursor for
select userid from inserted
open rs
fetch next from rs into @userid
while @@fetch_status=0
begin
if update(用户名)
begin
if(@userid='admin')
begin
raiserror('此用户名禁用!',10,1) with nowait
rollback
return
end
insert into new_users(userid) values (@userid)
end
fetch next from rs into @userid
end
close rs
deallocate rs
END
在用INSERT,DELETE,UPDATE更新表时,如果触发器执行的操作失败,对表的操作也会回滚，并提示触发器程序产生错误的位置与原因。