使用开窗函数来实现selectround(count(t3.user_id) /(select count(distinct user_id) from login),3) cnt1from(selectt1.user_id,t1.new_dt,count(t1.new_dt) cntfrom(selectt.user_id,t.date,t.rn,t.date + t.rn new_dtfrom(selectuser_id,date,row_number() over (partition by user_id order by date desc) rnfromlogin)t)t1grou...