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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 http://www.nowcoder.com/practice/d8a4f7b1ded04948b5435a45f03ead8c SELECT t3.difficult_level, (SUM(if(t2.result='right',1,0)) / C...

Mysql

2021-09-21

31 987

题解 | #统计每个用户的平均刷题数#

SELECT t1.university, t3.difficult_level, COUNT(t2.question_id) / COUNT(DISTINCT(t2.device_id)) as avg_answer_cnt from user_profile ...

Mysql

2021-09-20

442 14695