select deptno,ename,sal sal,average,sal-average diff
from emp,(select deptno dno,avg(sal) average from emp group by deptno)
where deptno=dno order by 1,2
不是說where裡不能用別名嗎?難道在subquery裡是例外?
from emp,(select deptno dno,avg(sal) average from emp group by deptno)
where deptno=dno order by 1,2
不是說where裡不能用別名嗎?難道在subquery裡是例外?
from emp,(select deptno dno,avg(sal) average from emp group by deptno) z
where emp.deptno=z.dno order by 1,2--这个你自己改吧.