28. Managers with at Least 5 Direct Reports
https://leetcode.com/problems/managers-with-at-least-5-direct-reports/description/
Write a solution to find managers with at least five direct reports. Return the result table in any order.
select name from employee where id in ( select managerId from employee group by managerId having count(*) >= 5 )
Join을 사용한 방법도 있음