题解 | #任意两个连续自然月练题次数大于1的用户#

select c.device_id
from
(select a.device_id
from
    (
    select device_id,count(question_id) cnt,month(event_date) as month
    from question_practice_detail
    group by device_id,month
    having cnt>1
  ) a
  left join (
    select device_id,count(question_id) cnt,month(event_date) as month
    from question_practice_detail
    group by device_id,month
    having cnt>1
  ) b
  on b.device_id=a.device_id
  where (b.month-a.month=1 or b.month-a.month=-11) and b.device_id is not null
  ) c
group by c.device_id
order by c.device_id desc