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(q.result='right',1,0))/count(qd.difficult_level) correct_rate from (select * from user_profile where university='浙江大学') u join question_practice_detail q on q.device_id=u.device_id left join question_detail qd on q.question_id=qd.question_id group by difficult_level order by correct_rate;
