Select EMP with max SAL from each DEPT

Question

I´m having a bad time with a SQL query. I´m using oracle default tables:

\'EMP\' TABLE

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AND

Answer 1

You can also use the analytical RANK() function:

SELECT * FROM (
  SELECT
    Dept.DeptNo,
    Dept.DName,
    Emp.EName,
    Emp.Sal,
    RANK() OVER (PARTITION BY Dept.DeptNo ORDER BY Emp.Sal DESC) AS DeptSalRank
  FROM Emp
  INNER JOIN Dept ON Emp.DeptNo = Dept.DeptNo
)
WHERE DeptSalRank = 1

Answer 2

Classic greatest-n-per-group query. Here is what you want:

select dept.dname, emp.empno, emp.ename, emp.sal
from emp
inner join dept on emp.deptno = dept.deptno
inner join
(
select emp.deptno, max(emp.sal) sal
from emp
group by emp.deptno
) ss on emp.deptno = ss.deptno and emp.sal = ss.sal
order by emp.sal desc

Here is a working fiddle: http://sqlfiddle.com/#!4/7147b/6

Additionally, you might want to checkout a different approach. Look here (SQL Select only rows with Max Value on a Column) to see an interesting answer on the topic.

Answer 3

The following query will omit duplicate values

SELECT DEPTNO, MAX(SAL) FROM EMP GROUP BY DEPTNO;

The following query will include the duplicate values

SELECT * FROM EMP WHERE (DEPTNO,SAL) IN 
( SELECT DEPTNO, MAX(SAL) FROM EMP GROUP BY DEPTNO)

Answer 4

As short as the question: SELECT DeptID, MAX(Salary) FROM Employees GROUP BY DeptID