Question

我需要帮助。我有表Employees和table Departments。我需要得到最高薪水的部门。我试试这个：

SELECT department_name,MAX(sum_salary) as sum_salary 
FROM (SELECT department_name,SUM(salary) AS sum_salary 
FROM EMPLOYEES,DEPARTMENTS 
WHERE DEPARTMENTS.DEPARTMENT_ID = EMPLOYEES.DEPARTMENT_ID 
GROUP BY DEPARTMENT_NAME)
GROUP BY DEPARTMENT_NAME;

但结果是部门列表，而不仅仅是一个值。

感谢您的帮助！

Answer 1

select 
  min(max(department_name)) keep (dense_rank last order by sum(salary))
    as department_name,
  min(sum(salary)) keep (dense_rank last order by sum(salary)) 
    as sum_salary
from EMPLOYEES join DEPARTMENTS using(department_id)
group by department_id

fiddle

Answer 2

如果在关系的情况下，你只想要一个，那么order by和某种形式的获得一行是有效的。 ANSI标准方法是：

SELECT d.DEPARTMENT_NAME, SUM(e.salary) AS sum_salary 
FROM EMPLOYEES e JOIN
     DEPARTMENTS d
     ON d.DEPARTMENT_ID = e.DEPARTMENT_ID 
GROUP BY d.DEPARTMENT_NAME
ORDER BY SUM(e.salary) DESC
FETCH FIRST 1 ROW ONLY;

请注意使用正确的JOIN语法和表别名。

编辑：

Oracle 12g支持上述语法。您可以在早期版本中执行以下操作：

SELECT t.*
FROM (SELECT d.DEPARTMENT_NAME, SUM(e.salary) AS sum_salary 
      FROM EMPLOYEES e JOIN
           DEPARTMENTS d
           ON d.DEPARTMENT_ID = e.DEPARTMENT_ID 
      GROUP BY d.DEPARTMENT_NAME
      ORDER BY SUM(e.salary) DESC
     ) t
WHERE rownum = 1;

Here's一个SQL小提琴。

Answer 3

等等 - 还有另一种方式：

WITH SUM_SAL AS (SELECT d.DEPARTMENT_NAME, SUM(e.SALARY) AS SUM_SALARY
                   FROM EMPLOYEES e
                   INNER JOIN DEPARTMENTS d
                     ON d.DEPARTMENT_ID = e.DEPARTMENT_ID
                   GROUP BY DEPARTMENT_NAME),
     MAX_SAL AS (SELECT MAX(SUM_SALARY) AS MAX_SALARY
                   FROM SUM_SAL)
SELECT s.DEPARTMENT_NAME, m.MAX_SALARY
  FROM SUM_SAL s
  INNER JOIN MAX_SAL m
    ON m.MAX_SALARY = s.SUM_SALARY;

SQLFiddle here

祝你好运。

SQL - 如何获得SUM的MAX？

3 个答案: