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 qd.difficult_level,sum(if(result = 'right',1,0))/count(qd.difficult_level) as correct_rate from question_practice_detail pqd,question_detail qd where pqd.question_id = qd.question_id and pqd.device_id in (select device_id from user_profile where university = '浙江大学') group by qd.difficult_level order by correct_rate