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 u.device_id from user_profile as u left join question_practice_detail as qpd on u.device_id = qpd.device_id where university = '北京大学' union select a.device_id from (select u.device_id, count(question_id) from user_profile as u left join question_practice_detail as qpd on u.device_id = qpd.device_id group by u.device_id having count(question_id) >2) as a order by device_id desc
union 去重 union all不去重
