题解 | #牛客每个人最近的登录日期(三)#

SELECT ROUND(COUNT(id)/COUNT(a.user_id),3) AS p
FROM
(SELECT user_id,MIN(DATE) AS DATE
FROM login
GROUP BY user_id
) AS a LEFT JOIN login AS b
ON a.user_id = b.user_id
#AND a.date+1 = b.date
and date_add(a.date,interval 1 day) = b.date