select author, date_format(start_time,'%Y-%m') as month, round((sum(if(if_follow=1, 1, 0))-sum(if(if_follow=2, 1, 0)))/count(*), 3) as fans_growth_rate, sum(sum(if(if_follow=1, 1, 0))-sum(if(if_follow=2, 1, 0)))over(partition by author order by date_format(start_time,'%Y-%m')) as total_fans from tb_...