PL/SQL group by

[a88622721]

select count(*),a.aa from abcd a where a.bb=bb group by a.aa
如何用 group by 显示 count（*）=0的那些行。

[学习中-------]

select count(*),a.aa from abcd a where a.bb=bb group by a.aa
having count(*)=0

[simonxt]

[Quote=引用楼主 的回复:]
select count(*),a.aa from abcd a where a.bb=bb group by a.aa
[/Quote]
从这个语句来说，既然都group by a.aa 了，所以不可能存在count（*）=0的行。

[simonxt]

唯一可能是 a.bb<>bb 的情况
所以顶多也就是
select * from abcd a where isnull(a.bb,'')<>bb -- isnull 防止字段出现null情况