题解 | #统计每个用户的平均刷题数#
统计每个用户的平均刷题数
https://www.nowcoder.com/practice/f4714f7529404679b7f8909c96299ac4
select university, difficult_level, count(qpd.question_id)/count(distinct up.device_id) as avg_answer_cnt from question_practice_detail as qpd left join user_profile as up on qpd.device_id=up.device_id left join question_detail as qd on qpd.question_id=qd.question_id group by university, difficult_level having university='山东大学'
这题好像这样也行
where university='山东大学'
group by university, difficult_level
投递科大讯飞等公司10个岗位
