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 dd.difficult_level difficult_level ,(ifnull((select count(dd1.result) from ( SELECT b.result , c.difficult_level FROM user_profile a left join question_practice_detail b on a.device_id = b.device_id left join question_detail c on b.question_id = c.question_id where a.university = '浙江大学') dd1 where dd1.result = 'right' and dd1.difficult_level is not null and dd1.difficult_level = dd.difficult_level group by dd1.difficult_level ),0) / count(dd.result)) correct_rate from ( SELECT b.result , c.difficult_level FROM user_profile a left join question_practice_detail b on a.device_id = b.device_id left join question_detail c on b.question_id = c.question_id where a.university = '浙江大学' ) dd where dd.difficult_level is not null group by dd.difficult_level order by correct_rate asc