ORA-00904: "AVGSAL": invalid identifier 求高手指点，贴有代码

[gmaxiaoxiang]

	select avg(sal) avgsal,deptno from emp group by deptno having avgsal=
	(
		select max(avg_sal) from 
		(
			select avg(sal) avg_sal,deptno from emp group by deptno
		)
	)

ORA-00904: "AVGSAL": invalid identifier

avgsal 这个不管改成什么都错误。。 不知道为什么，求高人帮忙

[shiyiwan]

别名在同一层级上不能用在条件中

select avg(sal) avgsal,deptno from emp group by deptno having avg(sal)=
    (
        select max(avg_sal) from 
        (
            select avg(sal) avg_sal,deptno from emp group by deptno
        )
    )

[wh62592855]