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 , university, sum(if(month(date) = 8 ,1 ,0)) as question_cnt, sum(if(result = 'right' , 1,0)) as right_question_cnt from user_profile U left join question_practice_detail Q on U.device_id = Q.device_id where university = '复旦大学' group by U.device_id