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 difficult_level, sum(case when result='right' then 1 else 0 end)/sum(case when difficult_level='easy' then 1 when difficult_level='medium' then 1 when difficult_level='hard' then 1 else 0 end) as correct_rate from question_practice_detail as qpd inner join question_detail as qd on qpd.question_id = qd.question_id where device_id in( select device_id from user_profile where university = '浙江大学') group by difficult_level order by correct_rate asc
感觉还挺直来直去的