题解 | #浙大不同难度题目的正确率#
浙大不同难度题目的正确率
https://www.nowcoder.com/practice/d8a4f7b1ded04948b5435a45f03ead8c
select c.difficult_level ,count(case when b.result='right' then b.question_id end)/count(b.question_id) as correct_rate from question_practice_detail b join question_detail c on b.question_id=c.question_id join user_profile a on a.device_id=b.device_id and a.university='浙江大学' group by c.difficult_level order by correct_rate
