Highest Salary in each department

Question

I have a table EmpDetails:

DeptID      EmpName   Salary
Engg        Sam       1000
Engg        Smith     2000
HR          Denis     1500
HR                  


        

Answer 1

Use correlated subquery:

SELECT DeptID, EmpName, Salary
FROM EmpDetails a
WHERE Salary = (SELECT MAX(Salary) 
                FROM EmpDetails b
                WHERE a.DeptID = b.DeptID)