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
p1.device_id,
university,
count(question_id) as question_cnt,
sum(
case when result="right" then 1 else 0 end
) as right_question_cnt
from
user_profile as p1
inner join question_practice_detail as p2 on p1.device_id = p2.device_id
where
month (date) = 8
and p1.university = "复旦大学"
group by
device_id;
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