[LeetCode] 1633. Perentage of Users Attended a Contest

 

 

[문제]

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[MySQL]

WITH Users_cnt AS (SELECT *
         , COUNT(*) OVER () AS user_cnt
    FROM Users
)

SELECT r.contest_id
     , ROUND(COUNT(DISTINCT r.user_id) / u.user_cnt *100 , 2) AS percentage
FROM Register AS r
    LEFT JOIN Users_cnt AS u ON r.user_id = u.user_id
GROUP BY r.contest_id
ORDER BY percentage DESC, contest_id ASC