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, round(ifnull((sum(case when qpd.result = 'right' then 1 else 0 end)/nullif(count(qd.question_id),0)),0),4) as correct_rate from user_profile up join question_practice_detail qpd on up.device_id = qpd.device_id left join question_detail qd on qd.question_id = qpd.question_id where up.university = '浙江大学' group by qd.difficult_level order by correct_rate asc;
