题解 | 每天登陆最早的用户的内容喜好

select 
  date(log_time) as log_day,
  a.user_id,
  b.hobby
from
  (
    select 
      user_id,
      log_time,
      dense_rank() over(partition by date(log_time) order by log_time asc) as log_time_rank
    from
      login_tb
  ) as a
left join 
  user_action_tb as b
on
  a.user_id=b.user_id
where
  log_time_rank in (1)
order by 
  log_day;