구름 아카이브

https://www.hackerrank.com/challenges/challenges/submissions/database/331359810 SELECT h.hacker_id , h.name , count(*) Challenges_created FROM Challenges c INNER JOIN Hackers h ON h.hacker_id = c.hacker_id GROUP BY h.hacker_id, h.name HAVING Challenges_created = (SELECT MAX(Challenges_created) --Challeges_created MAX 값이 50인 것 FROM( SELECT hacker_id , count(*) Challenges_created FROM Challenges G..

Top earners - 서브쿼리 https://www.hackerrank.com/challenges/earnings-of-employees/problem SELECT months*salary as earnings , count(*) FROM employee WHERE months*salary = (SELECT MAX(months*salary) FROM employee) GROUP BY earnings -- Having >>> GROUP BY 결과물을 다시 한 번 필터링 해줄 때 SELECT months*salary AS earnings , count(*) FROM employee GROUP BY earnings HAVING earnings = (SELECT MAX(months*salary) FROM e..

*** 다시 풀어볼 것 184. Department Highest Salary https://leetcode.com/problems/Department-Highest-Salary/ # 각각의 부서에서 누가 가장 고소득자인지 # sel 부서, 직원, 급여 # 순서 상관 x SELECT d.name AS Department , e.name AS Employee , e.salary AS Salary FROM employee as e INNER JOIN ( SELECT departmentID, MAX(salary) AS max_salary FROM Employee GROUP BY departmentID ) AS dh ON e.departmentID = dh.departmentID AND e.salary = dh..