题解 | #统计每个用户的平均刷题数#
统计每个用户的平均刷题数
https://www.nowcoder.com/practice/f4714f7529404679b7f8909c96299ac4
SELECT
u.university,
d.difficult_level,
COUNT(d.question_id) / COUNT(DISTINCT q.device_id) AS avg_answer_cnt
FROM
question_practice_detail q
LEFT JOIN user_profile u ON q.device_id = u.device_id
LEFT JOIN question_detail d ON q.question_id = d.question_id
WHERE
u.university = '山东大学'
GROUP BY
d.difficult_level
，目前也是月底了，面了大大小小很多次了，都没什么结果