题解 | #统计复旦用户8月练题情况#

select device_id, university, count(1) as question_cnt, sum(result = 'right') as right_question_cnt
from question_practice_detail inner join user_profile using(device_id)
where university = '复旦大学' and date_format(date,'%m') = '08'
group by device_id