LeetCode / 1907. Count Salary Categories / MySQL(Medium)

📚문제

출처 : LeetCode(https://leetcode.com/problems/count-salary-categories/)

📝풀이

SELECT 'High Salary' AS category
     , SUM(CASE WHEN income > 50000 THEN 1 ELSE 0 END) AS accounts_count
FROM Accounts

UNION

SELECT 'Average Salary' AS category
     , SUM(CASE WHEN income BETWEEN 20000 AND 50000 THEN 1 ELSE 0 END) AS accounts_count
FROM Accounts

UNION

SELECT 'Low Salary' AS category
     , SUM(CASE WHEN income < 20000 THEN 1 ELSE 0 END) AS accounts_count
FROM Accounts;

 

그냥 GROUP BY 해서 풀면

'Average Salary' 구간에 해당되지 않는 id도 있어서 아예 행이 나오지 않는다

 

쉽게 풀리는게 없다...🤯