LeetCode - 184. Department Highest Salary (MySQL)

Medium, SQL - Couple로 Tuple 비교하기

RunTime : 740 ms

문제

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

Return the result table in any order.

The result format is in the following example.

풀이

• 쌍으로 비교할 땐 =가 아니라 IN을 써야한다.
  • = 썼다가 계속 틀렸음

SELECT D.name AS Department, E.name AS Employee, E.salary AS Salary
FROM Department AS D JOIN Employee AS E ON E.departmentId = D.id
WHERE (Salary, E.departmentId) IN
(
    SELECT MAX(salary), departmentId FROM Employee
    GROUP BY departmentId
)