题解 | #浙江大学用户题目回答情况#
浙江大学用户题目回答情况
https://www.nowcoder.com/practice/55f3d94c3f4d47b69833b335867c06c1
select
up.device_id,qpd.question_id,qpd.result
from question_practice_detail qpd
INNER JOIN user_profile up
where up.university='浙江大学' and qpd.device_id=up.device_id
up.device_id,qpd.question_id,qpd.result
from question_practice_detail qpd
INNER JOIN user_profile up
where up.university='浙江大学' and qpd.device_id=up.device_id
order by question_id
INNER JOIN user_profile up:两个表操作,所以需要连接操作
where up.university='浙江大学' and qpd.device_id=up.device_id:连接两个表需要找到两个表所共有的属性,明显device_id符合,同时需要控制学校