题解 | #各个视频的平均完播率#

select
    video_id AS avg_comp_play_rate,
    round(avg((end_time - start_time) >= (select vi.duration from tb_video_info vi where vi.video_id = tb_user_video_log.video_id)), 3) AS avg_comp_play_rate
from tb_user_video_log
where year(start_time) = 2021
group by video_id
order by avg_comp_play_rate desc

用子查询来避免联表，我理解一般 tb_video_info 这个表的 video_id 都是有索引的，所以子查询应该会很快