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