【LeetCode-SQL】1141. 查询近30天活跃用户数一、题目二、解决三、参考
目录一、题目二、解决1、分组+时间间隔+distinct三、参考一、题目活动记录表：Activity+---------------+---------+| Column Name | Type |+---------------+---------+| user_id | int || session_id | int || activity_date | date || activity_type | enum |+------
