-- join两种写法 以及子查询 方法1： 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：

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' )

方法3： select a.device_id device_id,a.question_id question_id,a.result result from question_practice_detail a,user_profile b where b.device_id = a.device_id and university = '浙江大学'