1.从主从表中查询外键内容(常见问题)从主从表中查询对应的外键,需要指定外键的表,即sno=》 student.sno或者score.sno错误:select sno,sname,degree from student,score where student.sno=score.sno;正确:select student.sno,sname,degree from student,score where student.sno=score.sno;