query to find max salary code example

Example 1: how to get max salary in each department in sql

SELECT firstname, MAX(salary)
FROM department d LEFT OUTER JOIN employee e
ON (d.department_id = e.department_id)
GROUP BY department_id;

Example 2: how to find max and min salary in sql

SELECT MAX(SALARY) FROM EMPLOYEES
UNION
SELECT MIN(SALARY) FROM EMPLOYEES;

Example 3: sql highest salary by location

/*  Highest salary by Department/Location   */
SELECT e.ename, e.sal, e.deptno, d.loc
FROM emp e
JOIN dept d
ON e.deptno = d.deptno
WHERE e.sal in
( 	
  	select max(sal) 
  	from emp 
  	group by deptno
)