题解 | 每天登陆最早的用户的内容喜好
select t.date log_day, t.user_id, u.hobby from ( select user_id, date(log_time) date, rank()over(partition by date(log_time) order by log_time asc) rk from login_tb) t left join user_action_tb u on t. user_id = u. user_id where rk = 1 order by t.date