orm之多对多

class TeacherModel(models.Model):
    teacher_name = models.CharField(max_length=32)


    class Meta:
        db_table = ‘teacher‘



class StudentModel(models.Model):
    student_name = models.CharField(max_length=32)
    age = models.IntegerField(null=True)
    home = models.CharField(max_length=32)
    teacher = models.ManyToManyField(TeacherModel, related_name=‘stu‘)
    class Meta:
        db_table = ‘student‘

    def get(self, request):
    # 方法一：在建立manytomany的models里查数据
        teacherobj = models.TeacherModel.objects.get(id=2)
        data = teacherobj.stu.all()        #这是重点
        data_list = []
        for i in data:
            data_dic={
                "student_name":i.student_name,
                "teacher_name":teacherobj.teacher_name
            }
            data_list.append(data_dic)
        return Response(data_list)

    # 方法二：在未建立manytomany的models里查数据
        studentobj = models.StudentModel.objects.get(id=2)
        data = studentobj.teacher.all()      #这是重点
        data_list = []
        for i in data:
            data_dic = {
                "student_name": studentobj.student_name,
                "teacher_name": i.teacher_name
            }
            data_list.append(data_dic)
        return Response(data_list)

# 方法一：在建立manytomany的models里添加数据，（一条，一个对象）
        teacherobj = models.TeacherModel.objects.filter(id=2).first()
        studentobj = models.StudentModel.objects.filter(id=4).first()
        teacherobj.stu.add(studentobj)    #重点
        return Response({
            "status": 200
        })

#方法二：在未建立manytomany的models里添加数据，（一条，一个对象）
        teacherobj = models.TeacherModel.objects.all()
        studentobj = models.StudentModel.objects.filter(id=3).first()
        studentobj.teacher.set(teacherobj)    #重点
        return Response({
            "status": 200
        })

        # 方法一：在建立manytomany的models里修改数据，参数只能是可迭代对象
        teacherobj = models.TeacherModel.objects.filter(id=3).first()
        studentobj = models.StudentModel.objects.filter(id=2)
        teacherobj.stu.set(studentobj)    #重点
        return Response({
            "status": 200
        })

        #方法二：在未建立manytomany的models里修改数据，参数只能是可迭代对象
        # teacherobj = models.TeacherModel.objects.all()
        # studentobj = models.StudentModel.objects.filter(id=2).first()
        # studentobj.teacher.set(teacherobj)      #重点
        # return Response({
        #     "status": 200
        # })

        # 方法一：在建立manytomany的models里删除数据，（一条，一个对象）
        # teacherobj = models.Teacher.objects.filter(id=1).first()
        # studentobj = models.Student.objects.filter(id=2).first()
        # teacherobj.stu.remove(studentobj)   #重点
        # return Response({
        #     "status": 200
        # })

        #方法二：在未建立manytomany的models里删除数据，（多条，可迭代对象）
        teacherobj = models.TeacherModel.objects.all()
        studentobj = models.StudentModel.objects.filter(id=2).first()
        studentobj.teacher.remove(*teacherobj)     重点
        return Response({
            "status": 200
        })