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
t.university,
round(COUNT(p.question_id)/count(distinct(p.device_id)),4) AS avg_answer_cnt
FROM user_profile t
INNER JOIN question_practice_detail p
ON t.device_id = p.device_id
GROUP BY t.university
ORDER BY t.university;
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