题解 | #每类视频近一个月的转发量/率#

# 有用户互动
# 近一个月 每类视频的转发量和转发率（保留3位小数） 降序
select tag,sum(if_retweet) retweet_cut,
round(sum(if_retweet)/count(if_retweet), 3) retweet_rate
from tb_user_video_log a
inner join tb_video_info b on a.video_id=b.video_id
and timestampdiff(day,a.start_time,(select max(start_time)  from tb_user_video_log))<30
and timestampdiff(day,a.end_time,now())>=0
group by tag
order by retweet_rate desc

有用户互动是整张表的最早日期