题解 | #牛客每个人最近的登录日期(二)#

SELECT u.name u_n,c.name c_n,d date
FROM (
SELECT user_id,max(date) d 
FROM login
GROUP BY user_id) l
JOIN login l2
ON l.user_id=l2.user_id
AND l.d=l2.date
JOIN user u
ON u.id=l2.user_id
JOIN client c
ON c.id=l2.client_id
ORDER BY u_n;