1、 dense_rank() 相同排序+连续 1,1,2,3 select uid,count(*) exam_complete_cnt from( select id,uid,exam_id,start_time,DATE_FORMAT(start_time,'%Y-%m-01') start_days,submit_time,score,rn from ( select id,uid,exam_id,start_time,DATE_FORMAT(start_time,'%Y-%m-01') start_...