SQL语句

Oracle的EMP表,查询每个部门工资前三名的员工信息，如何写？？ 
解答：（通用sql）

from emp e1
where
   (
    select count(1)
    from emp e2
    where e2.deptno=e1.deptno and e2.sal>=e1.sal
   ) <=3 /*这里的数值表示你想取前几名*/
order by deptno, sal desc;

Oracle查询：（利用分区功能） 

(select deptno,ename,sal,row_number() over (partition by deptno
    order by sal desc) rn
from emp)
   where rn<3;