题解 | #每类视频近一个月的转发量/率#

select
    tag,
    sum(if_retweet) retweet_cut,
    round(avg(if_retweet), 3) retweet_rate
from
    tb_user_video_log l
    inner join tb_video_info i on l.video_id = i.video_id
where
    timestampdiff (day,
    date (l.start_time),
    date((select max(start_time) from tb_user_video_log))) < 30
group by
    tag
order by
    retweet_rate desc;