题解 | #近三个月未完成试卷数为0的用户完成情况#

with temp as (select *
                   , dense_rank() over (partition by uid order by date_format(start_time, '%Y%m') desc ) dr
              from exam_record)
select uid
     , count(submit_time) as exam_complete_cnt
from temp
where dr <= 3
group by uid
having count(start_time) = count(submit_time)
order by exam_complete_cnt desc, uid desc;