teacher --教师表
teacher_id--教师姓名或ID
class_id--班级
student--学生表
student_id--学生姓名或ID
teacher_id--教师姓名或ID
class_id--班级
score--成绩
select *
from studet
where class_id in (select class_id from teacher where teacher_id = '张老师')
order by class_id,score
王老湿
老王