[LeetCode] Employees Earning More Than Their Manager

https://leetcode.com/problems/employees-earning-more-than-their-managers/

Employees Earning More Than Their Managers - LeetCode

아마 관계형 DB를 배울 때 가장 유명한 예제가 아닐까? Employee의 Manager가 Employee에 속하는 것.
그 중에서 Salary를 비교하여 출력하는 예제였다.

# Write your MySQL query statement below
SELECT e1.Name as Employee
FROM Employee as e1
JOIN Employee as e2
ON e1.ManagerId=e2.Id and e2.Salary < e1.Salary;

JOIN을 사용했는데, 풀고 나서 Discussion을 보니 JOIN을 꼭 사용하지는 않아도 되었다.

FROM Employee as e1, Employee as e2

로 처리했어도 되더라!