题解 | #浙江大学用户题目回答情况#

记录一下等价的sql写法：

完整代码：

方法1代码: select qpd.device_id, qpd.question_id, qpd.result from question_practice_detail as qpd inner join user_profile as up on up.device_id=qpd.device_id and up.university='浙江大学'

方法2代码： select device_id, question_id, result from question_practice_detail where device_id in ( select device_id from user_profile where university='浙江大学' )