select tag, sum(if_retweet) retweet_cut, round(sum(if_retweet) / count(1),3) retweet_rate from tb_video_info a left join tb_user_video_log b on a.video_id = b.video_id WHERE DATEDIFF((SELECT MAX(end_time) FROM tb_user_video_log),start_time) <= 29 group by tag order by retweet_rate desc 注意要点:1、DAT...