oracle SQL：通过最小和最大和获得DEPT

Question

我有2个工作子查询，用于检查所有部门中的最小和最大SUMS（DEPTNO）。 表EMP和DEPT具有DEPTNO单元格

(SELECT min(sum(e.SAL)) FROM EMP e GROUP by e.DEPTNO);
(SELECT max(sum(e.SAL)) FROM EMP e GROUP by e.DEPTNO);

如何检查最小和最大子查询的DEPTNO？ 我的代码有错误：

SELECT d.DEPTNO 
FROM DEPT d 
WHERE sum(e.SAL) = (SELECT max(sum(e.SAL)) FROM EMP e GROUP by d.DEPTNO);

Answer 1

如果您希望部门获得最大的总和，则可以使用rownum或row_number() ：

select ed.*
from (select e.deptno, sum(e.sal) as sums,
             row_number() over (order by sum(e.sal) desc) as seqnum
      from emp e
      group by e.deptno
     ) ed
where seqnum = 1;

在Oracle 12g +中，也可以写成：

      select e.deptno, sum(e.sal) as sums,
             row_number() over (order by sum(e.sal) desc) as seqnum
      from emp e
      group by e.deptno
      order by sum(e.sal) desc
      fetch first 1 row only;

Answer 2

这是使用cte一种方法

with salsums as (select deptno, sum(sal) salsum from emp group by deptno)
, maxandmin as (select max(salsum) maxsal, min(salsum) minsal from salsums)
select deptno 
from salsums cross join maxandmin
where salsum = maxsal or salsum = minsal

Answer 3

好的，这比开始时要难。 这就是我最终使它工作的方式，但是我更喜欢@vkp的答案。

with sums as
(
  SELECT DEPTNO, SUM(SAL) AS SSAL
  FROM EMP
  GROUP BY DEPTNO
), mm as
(
  SELECT DEPTNO, SSAL, MIN(SSAL) OVER () as MIN_SSAL, MAX(SSAL) OVER () as MAX_SSAL
  FROM SUMS
)
SELECT 'MIN', DEPTNO, SSAL FROM mm WHERE SSAL=MIN_SSAL
UNION ALL
SELECT 'MAX', DEPTNO, SSAL FROM mm WHERE SSAL=MAX_SSAL

http://sqlfiddle.com/#!6/410c8/8