题解 | 每天登陆最早的用户的内容喜好
每天登陆最早的用户的内容喜好
https://www.nowcoder.com/practice/24bb13a28267486ba86c1d21459fa90a
select log_day,t2.user_id,hobby from ( select * ,dense_rank()over(partition by log_day order by log_date) ranking from( select user_id uid,left(log_time,10) log_day,right(log_time,8) log_date from login_tb) as t1 join user_action_tb uat on t1.uid = uat.user_id) as t2 where ranking = 1
1.把日期分开
2.进行排序
3.表连接
4.筛选排名为1的
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