MAX function is an aggregate function that allows you to get the maximum of values.
Consider the employee table as shown below:
You can get the maximum of all salaries as shown below:
SELECT MAX(salary) FROM employee; sum ------ 72,000
You can use MAX function along with the group by clause. Example: To return maximum of salaries per department, you can group by department as shown below:
SELECT department, MAX(salary) FROM employee GROUP BY department; department sum ---------- --- sales 60,000 accounts 65,000 support 72,000
You can filter grouped results using HAVING clause. Example: Below query returns only the departments that are paying a maximum salary of more than 60,000.
SELECT department, MAX(salary) FROM employee GROUP BY department HAVING MAX(salary)>60000; department sum ---------- --- accounts 65,000 support 72,000