with cte as( select device_id,date_format(event_date,'%Y%m') as event_month,count(*) as num from question_practice_detail group by device_id,event_month ), cte1 as ( select a.device_id,a.num+b.num as cnt from cte a left join cte b on a.device_id=b.device_id and period_diff(a.event_month,b.event_month)=1 where b.event_month is not null ) select device_id from cte1 group by device_id having min(cnt)>1 order by device_id desc