题解 | #每个创作者每月的涨粉率及截止当前的总粉丝量#

SELECT 
    author, 
    date_format(start_time,'%Y-%m') month,
      round(sum(if(if_follow=2,-1,if_follow)) / count(*),3) as fans_growth_rate, 
     sum(sum(if(if_follow=2,-1,if_follow))) over(partition by author order by date_format(start_time,'%Y-%m')) total_fans
FROM tb_user_video_log log 
left join tb_video_info info on log.video_id=info.video_id
where year(start_time)=2021
group by author,month
order by author,total_fans