题解 | #统计复旦用户8月练题情况#

select u.device_id, u.university,
sum(if(result is not null, 1, 0) ) 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
where u.university = '复旦大学' and q.date like '%08-%'
group by u.device_id