题解 | #每类视频近一个月的转发量/率#
每类视频近一个月的转发量/率
http://www.nowcoder.com/practice/a78cf92c11e0421abf93762d25c3bfad
select ti.tag, sum(if(if_retweet = 1,1,0)) retweet_cnt, round(sum(if(if_retweet = 1,1,0))/count(*),3) retweet_rate from tb_user_video_log tl join tb_video_info ti on tl.video_id = ti.video_id where datediff((select max(start_time) FROM tb_user_video_log),tl.start_time)<=29 group by ti.tag order by retweet_rate desc
