select author, month, round(total_fans / open_total, 3), sum(total_fans) over(partition by author order by month) as total_fans from ( select b.author, date_format(a.start_time, "%Y-%m") as month, count(1) as open_total, sum(case when if_follow = 1 then 1 when if_follow = 2 then -1 else 0 end) as to...