select tb_video_info.video_id, round(sum(if((date_add(start_time,interval duration second))<=end_time,1,0))/count(uid),3)  avg_comp_play_rate from tb_user_video_log  left join tb_video_info on tb_user_video_log.video_id=tb_video_info.video_id  where year(start_time)=2021 group by video_id order b...