题解 | #统计复旦用户8月练题情况#
统计复旦用户8月练题情况
https://www.nowcoder.com/practice/53235096538a456b9220fce120c062b3
select u.device_id, u.university, count(if(month(q.date) = 8, q.device_id, null)) as question_cnt, count(if(q.result = 'right', q.result, null)) as right_question_cnt from user_profile u left join question_practice_detail q on u.device_id = q.device_id where u.university = '复旦大学' group by u.device_id