select submit_month as month, round(count(distinct uid,submit_day)/count(distinct uid),2) as avg_active_days,count(distinct uid) as mau from ( select id,uid,exam_id,submit_time,date_format(submit_time,'%Y%m%d') as submit_day,date_format(submit_time,'%Y%m')as submit_month from exam_record where submi...
