[LeetCode] 184. Department Highest Salary

내 쿼리

SELECT d.name AS Department
    ,e.name AS Employee
    ,e.salary AS Salary
FROM employee AS e
INNER JOIN department AS d
ON e.departmentid = d.id
WHERE (e.departmentid ,e.salary)
    IN (SELECT departmentid , MAX(salary) FROM employee GROUP BY departmentid )

 

SQL은 다중 컬럼 인덱싱이 가능하다