题解 | 每天登陆最早的用户的内容喜好

select log_day,user_id,hobby
from(
    select u.user_id,u.hobby,
    substr(l.log_time,1,10) as log_day,rank() over(partition by substr(l.log_time,1,10) order by l.log_time) as rk
    from login_tb l
    join user_action_tb u
    on l.user_id = u.user_id
)a
where a.rk =1

简单