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
university,
COUNT(question_id)/COUNT(DISTINCT a.device_id) avg_answer_cnt
FROM
user_profile a
RIGHT JOIN question_practice_detail b ON a.device_id=b.device_id
GROUP BY
university
ORDER BY
university
