select up.device_id, '复旦大学' as university,
count(question_id) as question_cnt,
sum(if(qpd.result='right', 1, 0)) as right_question_cnt
from user_profile as up
left join question_practice_detail as qpd
on qpd.device_id = up.device_id and month(qpd.date) = 8
where up.university = '复旦大学'
group by up.device_id
select u.device_id, u.university,
count(q.question_id) as question_cnt,
sum(if(q.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 and month(date) = 8
where u.university = '复旦大学'
group by u.device_id
