牛客SQL刷題第三趴——SQL大廠面試真題

• 2022 年 7 月 14 日
• 筆記
• My SQL, MySQL

01 某音短視頻

SQL156 各個視頻的平均完播率

【描述】用戶-視頻互動表tb_user_video_log。（uid-用戶ID, video_id-視頻ID, start_time-開始觀看時間, end_time-結束觀看時間, if_follow-是否關注, if_like-是否點贊, if_retweet-是否轉發, comment_id-評論ID）

短視頻信息表tb_video_info。（video_id-視頻ID, author-創作者ID, tag-類別標籤, duration-視頻時長（秒）, release_time-發佈時間）

【問題】計算2021年里有播放記錄的每個視頻的完播率(結果保留三位小數)，並按完播率降序排序

select t.video_id,
ROUND(sum(if((t.end_time-t.start_time)>=t1.duration,1,0))/count(start_time),3) as avg_comp_play_rate
from tb_user_video_log t 
left join tb_video_info t1
on t.video_id=t1.video_id
where year(t.start_time)='2021'
group by t.video_id
order by avg_comp_play_rate desc;

select t1.tag,
concat(ROUND(avg(if(timestampdiff(second,t.start_time,t.end_time)>=t1.duration,1,
             timestampdiff(second,t.start_time,t.end_time)/t1.duration))*100,2),'%') as avg_play_progress
from tb_video_info t1
join tb_user_video_log t
on t1.video_id=t.video_id
group by t1.tag
having avg_play_progress>60
order by avg_play_progress desc;