关于 not in的疑问
挨踢直男 2010-05-23 04:53:25 if object_id('tb') is not null
drop table tb
create table tb
(
id int
)
insert tb select 1
union all
select null
union all
select 2
if object_id('t1') is not null
drop table t1
create table t1
(
col int
)
insert t1 select 1
union all
select 3
select * from t1 where col not in (select * from tb)
这个为什么会没有值啊
t1表中的 col = 3 这条记录明明符合要求的啊