题解 | #统计复旦用户8月练题情况#
浙大不同难度题目的正确率
http://www.nowcoder.com/practice/d8a4f7b1ded04948b5435a45f03ead8c
from user_profile up,question_practice_detail qpd,question_detail qd
where university='浙江大学' and up.device_id=qpd.device_id and qpd.question_id=qd.question_id
group by difficult_level
order by correct_rate