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,
u.university,
count(if(q.question_id is null,0,1)) as question_cnt,
sum(
if(q.result='right',1,0)
) as
right_question_cnt
from user_profile as u
left join question_practice_detail as 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
