文章來(lái)源:http://www.zghlxwxcb.cn/news/detail-545088.html
文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-545088.html
SELECT
u.university,
qd.difficult_level,
count(q.question_id)/count(distinct(q.device_id)) AS avg_answer_cnt
FROM question_practice_detail AS q
LEFT JOIN user_profile AS u
ON u.device_id=q.device_id
LEFT JOIN question_detail AS qd
ON q.question_id=qd.question_id
GROUP BY u.university, qd.difficult_level;
到了這里,關(guān)于SQL23 統(tǒng)計(jì)每個(gè)學(xué)校各難度的用戶平均刷題數(shù)的文章就介紹完了。如果您還想了解更多內(nèi)容,請(qǐng)?jiān)谟疑辖撬阉鱐OY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章,希望大家以后多多支持TOY模板網(wǎng)!