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