题解 | 统计每个学校各难度的用户平均刷题数
统计每个学校各难度的用户平均刷题数
https://www.nowcoder.com/practice/5400df085a034f88b2e17941ab338ee8
SELECT
u.university,
qd.difficult_level,
ROUND(COUNT(qpd.question_id)/COUNT(DISTINCT device_id),4) AS avg_answer_cnt
FROM user_profile u
JOIN question_practice_detail qpd USING(device_id)
JOIN question_detail qd USING(question_id)
GROUP BY u.university,qd.difficult_level
查看7道真题和解析
hc锁了早不说，给我拖了快20天都没约上面，之后告诉我没hc了