SELECT every employee that has a higher salary than the AVERAGE of his department

Question

I have only 1 table named EMPLOYEE on my database with the 3 following collumns:

Employee_Name, Employee_Salary, Department_ID

Answer 1

Try This... This not tested.

SELECT * from employee join (SELECT AVG(employee_salary) as sal, department_ID 
FROM employee GROUP BY Department_ID) as t1 
ON employee.department_ID = t1.department_ID 
where employee.employee_salary > t1.sal