题解 | 每天登陆最早的用户的内容喜好

with
    t1 as (
        select
            l.user_id,
            log_time,
            hobby,
            dense_rank() over (
                partition by
                    date (log_time)
                order by
                    log_time
            ) as rk
        from
            login_tb l
            left join user_action_tb u on l.user_id = u.user_id
    )
select date(log_time) log_day,user_id,hobby from t1 where rk = 1 order by log_day

给每天的登录日期分区按照时间升序排序分配序号，t1表查出来的结果