LeetCode（数据库）- 2020年最后一次登录

Posted 2021-12-28 程序员牧码

题目链接：点击打开链接

题目大意：略。

解题思路：略。

AC 代码

-- 解决方案(1)
SELECT user_id AS 'user_id',
    MAX(time_stamp) AS 'last_stamp'
FROM Logins
WHERE YEAR(time_stamp) = '2020'
GROUP BY user_id;

-- 解决方案(2)
SELECT user_id, time_stamp last_stamp
FROM (SELECT user_id, time_stamp, RANK() OVER(PARTITION BY user_id ORDER BY time_stamp DESC) rk
FROM Logins
WHERE YEAR(time_stamp) = '2020') t
WHERE rk = 1