查询「」老师授课的同学的信息select student.*from student, scwhere student.sid = sc.sidand sc.cid in (select cid from course, teacher where course.tid = teacher.tid and Tname = '')同时连接多张表select student.*from teacher ,course ,student, scwhere teacher.Tname=''and teacher.TId=course.TIdand course.CId=sc.CIdand sc.SId=student.SId