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
http://www.nowcoder.com/practice/53235096538a456b9220fce120c062b3
清晰明了
select u.device_id,university,count(question_id) question_cnt, sum(if(result='right',1,0)) right_question_cnt from user_profile u left join question_practice_detail q on u.device_id=q.device_id and MONTH(date)=8 where university='复旦大学' group by u.device_id
