题解 | #北京大学或练题数大于2的学生ID#
北京大学或练题数大于2的学生ID
https://www.nowcoder.com/practice/b2b639586d89409b9c1fa82c083287dd
select distinct c.device_id from (select
a.device_id
from
user_profile a,
question_practice_detail b
where
a.device_id = b.device_id
group by
b.device_id
having
count(question_id) > 2
union all
select
device_id
from
user_profile
where
university = '北京大学') c order by device_id desc
