平均播放进度大于60%的视频类别
明确题意:
计算各类视频的平均播放进度,将进度大于60%的类别输出
问题分解:
- 关联用户-视频互动记录和短视频信息表:JOIN tb_video_info USING(video_id);
- 按视频类别分组:GROUP BY tag
- 计算每个类别的平均播放进度:
- 播放进度=播放时长÷视频时长*100%
- 播放时长=TIMESTAMPDIFF(SECOND, start_time, end_time);特殊情况:播放时长大于视频时长时,播放进度为100%(加个IF判断)
- 平均进度=AVG(每个进度)
- 结果保留2位小数:ROUND(x, 2)
- 百分比格式化:CONCAT(x, '%')
- 计算公式:
ROUND(AVG(
IF(TIMESTAMPDIFF(SECOND, start_time, end_time) > duration, 1,
TIMESTAMPDIFF(SECOND, start_time, end_time) / duration)
) * 100, 2) as avg_play_progress
- 筛选播放进度>60%的视频类别:HAVING avg_play_progress > 60
细节问题:
- 表头重命名:as
- 按播放进度倒序排序:ORDER BY avg_play_progress DESC;
完整代码:
SELECT tag, CONCAT(avg_play_progress, "%") as avg_play_progress
FROM (
SELECT tag,
ROUND(AVG(
IF(TIMESTAMPDIFF(SECOND, start_time, end_time) > duration, 1,
TIMESTAMPDIFF(SECOND, start_time, end_time) / duration)
) * 100, 2) as avg_play_progress
FROM tb_user_video_log
JOIN tb_video_info USING(video_id)
GROUP BY tag
HAVING avg_play_progress > 60
ORDER BY avg_play_progress DESC
) as t_progress;