Check this:
sql - Highest Salary in each department - Stack Overflow[
^]
You have to change it to your needs:
WITH cteRowNum AS (
SELECT DeptID, EmpName, Salary,
DENSE_RANK() OVER(PARTITION BY DeptID ORDER BY Salary DESC) AS RowNum
FROM EmpDetails
)
SELECT DeptID, EmpName, Salary
FROM cteRowNum
WHERE RowNum = 1;