[Leetcode, PostgreSQL] 184. Department Highest Salary

문제

• Write a solution to find employees who have the highest salary in each of the departments.

코드

SELECT B.NAME AS DEPARTMENT, 
        A.NAME AS EMPLOYEE,
        A.SALARY AS SALARY
FROM EMPLOYEE A, 
    DEPARTMENT B
WHERE A.DEPARTMENTID = B.ID AND 
        (A.DEPARTMENTID, A.SALARY) IN (
                                        SELECT DEPARTMENTID, MAX(SALARY) AS MAX_SALARY 
                                        FROM EMPLOYEE 
                                        GROUP BY DEPARTMENTID
                                      ) 
;