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各个视频的平均完播率

[编程题]各个视频的平均完播率
  • 热度指数：268938 时间限制：C/C++ 1秒，其他语言2秒 空间限制：C/C++ 256M，其他语言512M
  • 算法知识视频讲解
用户-视频互动表tb_user_video_log

（uid-用户ID, video_id-视频ID, start_time-开始观看时间, end_time-结束观看时间, if_follow-是否关注, if_like-是否点赞, if_retweet-是否转发, comment_id-评论ID）

短视频信息表tb_video_info

（video_id-视频ID, author-创作者ID, tag-类别标签, duration-视频时长（秒）, release_time-发布时间）

问题：计算2021年里有播放记录的每个视频的完播率(结果保留三位小数)，并按完播率降序排序(注意：计算的是2021年的数据)
注：视频完播率是指完成播放次数占总播放次数的比例。简单起见，结束观看时间与开始播放时间的差>=视频时长时，视为完成播放。

输出示例：
示例数据的结果如下：

解释：
视频2001在2021年10月有3次播放记录，观看时长分别为30秒、24秒、34秒，视频时长30秒，因此有两次是被认为完成播放了的，故完播率为0.667；
视频2002在2021年9月和10月共2次播放记录，观看时长分别为42秒、30秒，视频时长60秒，故完播率为0.000。
示例1

输入

DROP TABLE IF EXISTS tb_user_video_log, tb_video_info;
CREATE TABLE tb_user_video_log (
    id INT PRIMARY KEY AUTO_INCREMENT COMMENT '自增ID',
    uid INT NOT NULL COMMENT '用户ID',
    video_id INT NOT NULL COMMENT '视频ID',
    start_time datetime COMMENT '开始观看时间',
    end_time datetime COMMENT '结束观看时间',
    if_follow TINYINT COMMENT '是否关注',
    if_like TINYINT COMMENT '是否点赞',
    if_retweet TINYINT COMMENT '是否转发',
    comment_id INT COMMENT '评论ID'
) CHARACTER SET utf8 COLLATE utf8_bin;

CREATE TABLE tb_video_info (
    id INT PRIMARY KEY AUTO_INCREMENT COMMENT '自增ID',
    video_id INT UNIQUE NOT NULL COMMENT '视频ID',
    author INT NOT NULL COMMENT '创作者ID',
    tag VARCHAR(16) NOT NULL COMMENT '类别标签',
    duration INT NOT NULL COMMENT '视频时长(秒数)',
    release_time datetime NOT NULL COMMENT '发布时间'
)CHARACTER SET utf8 COLLATE utf8_bin;

INSERT INTO tb_user_video_log(uid, video_id, start_time, end_time, if_follow, if_like, if_retweet, comment_id) VALUES
  (101, 2001, '2021-10-01 10:00:00', '2021-10-01 10:00:30', 0, 1, 1, null),
  (102, 2001, '2021-10-01 10:00:00', '2021-10-01 10:00:24', 0, 0, 1, null),
  (103, 2001, '2021-10-01 11:00:00', '2021-10-01 11:00:34', 0, 1, 0, 1732526),
  (101, 2002, '2021-09-01 10:00:00', '2021-09-01 10:00:42', 1, 0, 1, null),
  (102, 2002, '2021-10-01 11:00:00', '2021-10-01 11:00:30', 1, 0, 1, null);

INSERT INTO tb_video_info(video_id, author, tag, duration, release_time) VALUES
  (2001, 901, '影视', 30, '2021-01-01 7:00:00'),
  (2002, 901, '美食', 60, '2021-01-01 7:00:00'),
  (2003, 902, '旅游', 90, '2021-01-01 7:00:00');

输出

2001|0.667
2002|0.000
算法知识视频讲解
添加回答
Mysql
牛客466715931号头像 牛客466715931号
select video_id,round(sum(a)/count(video_id),3) avg_comp_play_rate from(select s.video_id video_id,s.start_time,s.end_time,t.duration,case when s.end_time-s.start_time>=t.duration then 1 else 0 end a from tb_user_video_log s join tb_video_info t on s.video_id=t.video_id WHERE year(start_time) = 2021
) b group by video_id order by avg_comp_play_rate desc;


一定得加where 虽然数据里没有别的年份
发表于 2025-07-02 20:05:45 回复(0)
Mysql
Dawn0614头像 Dawn0614 
select a.video_id,round(count(if(time_diff>=duration,1,null))/count(uid),3) as avg_comp_play_rate from
(select uid,video_id,timestampdiff(second,start_time,end_time) as time_diff,start_time from tb_user_video_log)a
left join 
(select video_id,duration from tb_video_info)b
on a.video_id=b.video_id
where year(start_time)=2021
group by a.video_id
order by avg_comp_play_rate DESC

发表于 2025-06-17 14:56:05 回复(0)
Mysql
等offer的萝卜头像 等offer的萝卜
SELECT a.video_id, ROUND(SUM(IF(watch_time >= duration, 1, 0))/COUNT(*), 3) AS avg_comp_play_rate
FROM (
    SELECT video_id, TIMESTAMPDIFF(SECOND, start_time, end_time) AS watch_time
    FROM tb_user_video_log
    WHERE YEAR(end_time) = 2021
)a LEFT JOIN tb_video_info b
ON a.video_id = b.video_id
GROUP BY a.video_id
ORDER BY avg_comp_play_rate DESC;
发表于 2025-03-24 14:08:51 回复(0)
Mysql
i橙头像 i橙 
with t1 as(
select tv.video_id,
if(TIMESTAMPDIFF(SECOND, start_time, end_time)- duration>=0,1,0) as flag,
duration
from  tb_video_info as tv
left join tb_user_video_log as tu using(video_id)
where year(release_time)='2021'
)
select video_id,round(avg(flag),3) as avg_comp_play_rate
from t1
group by video_id
ORDER BY avg_comp_play_rate DESC
不知道错哪儿了哎....
发表于 2025-02-14 17:45:51 回复(0)
Mysql
风也温柔_头像 风也温柔_ 
WITH A AS(
    SELECT
        u.video_id,
        v.duration,	
        TIMESTAMPDIFF(SECOND,start_time,end_time) AS play_time
    FROM tb_user_video_log u
    JOIN tb_video_info v USING (video_id)
    WHERE YEAR(start_time)='2021'
)
SELECT
    video_id,	
    FORMAT(AVG(IF(play_time>=duration,1,0)) ,3) AS avg_comp_play_rate
FROM A
GROUP BY video_id
ORDER BY avg_comp_play_rate DESC

发表于 2024-12-24 20:08:43 回复(0)
Mysql
牛客393777248号头像 牛客393777248号 
SELECT
u.video_id,
round(sum(case when TIMESTAMPDIFF(second,u.start_time,u.end_time) >= v.duration then 1 else 0 end) / count(u.video_id),3) as avg_comp_play_rate
FROM tb_user_video_log u 
inner join tb_video_info v on u.video_id = v.video_id
where YEAR(u.start_time) = '2021'
GROUP BY 1
order by avg_comp_play_rate desc

发表于 2024-09-10 11:21:05 回复(0)
Mysql
想开了的乌龟很神奇头像 想开了的乌龟很神奇
select
    tuvl.video_id,
    round(
        avg(
            time_to_sec (tuvl.end_time) - time_to_sec (tuvl.start_time) >= tvi.duration
        ),
        3
    ) as avg_comp_play_rate
from
    tb_user_video_log tuvl
    join tb_video_info as tvi on tuvl.video_id = tvi.video_id
where
    year (tuvl.start_time) = 2021
group by
    tuvl.video_id
order by
    avg_comp_play_rate desc
发表于 2024-09-06 15:12:44 回复(0)
Mysql
Lilyttx头像 Lilyttx 
SELECT 
    user.video_id,
    round(count(IF(USE_TIME >= duration,1,NULL))/count(duration),3) AS avg_comp_play_rate
FROM
    (SELECT
        uid,
        video_id,
        TIMESTAMPDIFF(second, start_time, end_time) AS USE_TIME
    FROM
        tb_user_video_log
    WHERE YEAR(start_time) = 2021) AS user
    INNER JOIN tb_video_info AS video ON user.video_id = video.video_id
GROUP BY
    video_id
ORDER BY
    avg_comp_play_rate DESC

发表于 2024-09-06 12:07:16 回复(0)
Mysql
只想搞钱的王心凌男孩很想去重庆头像 只想搞钱的王心凌男孩很想去重庆

select
video_id,round(sum(if_all_duration)/count(*),3) as avg_comp_play_rate
from
(
select
t1.*,
case when duration_in_seconds >= duration then 1
else 0
end as if_all_duration
from
(
select t2.video_id,t2.duration, coalesce(timestampdiff(second,t1.start_time,t1.end_time),0) as duration_in_seconds  
from tb_video_info t2
left join tb_user_video_log t1
on  t2.video_id = t1.video_id and year(t1.start_time) = 2021
)t1
)t2
group by video_id
order by avg_comp_play_rate desc


发表于 2024-08-26 16:31:34 回复(0)
Mysql
小花鸡头像 小花鸡
select
    u.video_id,
    round(
        avg(
            case
                when u.end_time - u.start_time >= v.duration then 1
                else 0
            end
        ),
        3
    ) avg_comp_play_rate
from
    tb_user_video_log u
    inner join tb_video_info v on v.video_id = u.video_id
where
    year(start_time)='2021'
    and year(end_time)='2021'
group by
    u.video_id
order by
    avg_comp_play_rate desc

发表于 2024-08-02 11:27:45 回复(0)
Mysql
牛客166611890号头像 牛客166611890号
"计算2021年里有播放记录的每个视频"，这句话有歧义吧
1，计算2021年里“有播放记录的每个”视频
2，计算“2021年里有播放记录”的每个视频
出题人是第二个意思，所以WHERE条件里应该是
YEAR(start_time)=2021
而不是
WHERE YEAR(release_time)=2021
让人头痛了很久....
发表于 2024-07-15 17:00:27 回复(0)
Mysql
yuciaaa头像 yuciaaa 
WITH A AS(
    SELECT tb_user_video_log.video_id, CASE WHEN end_time - start_time >= duration
                                        THEN 1
                                        ELSE 0
                                        END
                                        AS wb, start_time
    FROM tb_user_video_log 
    LEFT JOIN tb_video_info ON tb_video_info.video_id = tb_user_video_log.video_id
    WHERE year(start_time) = 2021
),
B AS(
    SELECT video_id, ROUND(SUM(wb)/COUNT(*), 3) AS wbr
    FROM A
    GROUP BY video_id
)
SELECT * FROM B
ORDER BY wbr DESC

发表于 2024-06-15 23:56:43 回复(0)
Mysql
牛客678711165号头像 牛客678711165号 
Select vi.video_id,
round(SUM(If((vl.end_time-vl.start_time)>=vi.duration,1,0))/Count(vi.video_id),3) as avg_comp_play_rate
from tb_user_video_log vl
Right Join tb_video_info vi
Using (video_id)
group by vi.video_id
无语了自测运行啥事没有，一提交就报错
发表于 2024-05-29 11:46:50 回复(0)
Mysql
Tayspirit头像 Tayspirit 
select a.video_id,
(case when timestampdiff(second,a.start_time,a.end_time)>=b.duration then format(count(a.video_id)/count(a.uid),3) 
else 0.000 end) as avg_comp_play_rate 
from
tb_user_video_log a inner join tb_video_info b
on a.video_id=b.video_id
where year(start_time)=2021 and year(end_time)=2021
group by a.video_id 
order by avg_comp_play_rate desc;
程序异常退出, 请检查代码"是否有数组越界等异常"或者"是否有语法错误"
SQL_ERROR_INFO: "Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'a.start_time' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by"

绝望了，真的不知道哪里出问题了T-T


发表于 2024-04-16 22:22:21 回复(0)
Mysql
牛客466864729号头像 牛客466864729号 
select
    user.video_id,
    round(count(if(TIMESTAMPDIFF(second,user.start_time,user.end_time) >= video.duration,1,null))/count(*),3) as avg_comp_play_rate
from
    tb_user_video_log as user
left join
    tb_video_info as video
on user.video_id = video.video_id
where Year(user.start_time) = '2021'
group by user.video_id
order by avg_comp_play_rate DESC


发表于 2024-04-04 11:49:55 回复(0)
Mysql
牛客854222746号头像 牛客854222746号
#使用sum和count(*)
select tuvl.video_id, round(sum(if(TIMESTAMPDIFF(SECOND, tuvl.start_time, tuvl.end_time) >= duration, 1, 0)) / count(*), 3) as avg_comp_paly_rate
from tb_user_video_log tuvl left join tb_video_info tvi on tuvl.video_id = tvi.video_id
where year(tuvl.start_time) = 2021 and year(tuvl.end_time) = 2021
group by tuvl.video_id
order by avg_comp_paly_rate desc

#使用avg
select tuvl.video_id, round(avg(if(TIMESTAMPDIFF(SECOND, tuvl.start_time, tuvl.end_time) >= duration, 1, 0)), 3) as avg_comp_paly_rate
from tb_user_video_log tuvl left join tb_video_info tvi on tuvl.video_id = tvi.video_id
where year(tuvl.start_time) = 2021 and year(tuvl.end_time) = 2021
group by tuvl.video_id
order by avg_comp_paly_rate desc
发表于 2024-04-01 16:12:14 回复(0)
Mysql
牛客147531661号头像 牛客147531661号
SELECT video_id,1-ROUND(T1/COUNT(video_id),3) X
FROM tb_user_video_log
RIGHT JOIN
    (SELECT video_id ,COUNT(video_id) T1
    FROM tb_user_video_log
    RIGHT JOIN tb_video_info
    USING(video_id)
    WHERE end_time-start_time < duration
    GROUP BY video_id
)T2
USING(video_id)
GROUP BY video_id
ORDER BY X DESC

为什么2003计算出0.5！？
编辑于 2024-03-30 18:16:49 回复(1)
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