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
WITH CTE1 AS
(
SELECT *
FROM question_practice_detail
JOIN user_profile
USING(device_id)
)
SELECT university,
ROUND(COUNT(*) / COUNT(DISTINCT device_id), 4) AS avg_answer_cnt
FROM CTE1
GROUP BY university
