多表查询法一表联立的关键是正确连接和正确查询select q.device_id, q.question_id, q.resultfrom question_practice_detail as qinner join user_profile as uon q.device_id = u.device_idwhere u.university = '浙江大学';法二子查询的关键是锁定两张表的相同列,然后利用筛选条件选出要找的行的位置,最后利用位置选中另一张表中的数据select device_id, question_id, result from question_practice_detailwhere device_id in ( select device_id from user_profile where university = '浙江大学')