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,
count(*) as question_cnt,
sum(case
when result = 'right' then 1
else 0
end) as right_question_cnt
from
question_practice_detail as Q left join user_profile as U
on
Q.device_id = U.device_id
where
university = '复旦大学' and month(date) = 8
group by
U.device_id
