题解 | #统计每个学校的答过题的用户的平均答题数#
统计每个学校的答过题的用户的平均答题数
https://www.nowcoder.com/practice/88aa923a9a674253b861a8fa56bac8e5
SELECT
u.university,
COUNT(question_id) / COUNT(DISTINCT q.device_id)
FROM
question_practice_detail q
LEFT JOIN user_profile u ON q.device_id = u.device_id
GROUP BY
u.university
ORDER BY
u.university ASC
查看2道真题和解析