Django Models.py N对N的关系，总是说一个对象没有定义

Question

我正在与学院、教师和学生一起使用 Django 项目进行简单测试。

我正在尝试这个：

class Student(models.Model):
    name = models.CharField()
    direction = models.CharField()
    city = models.CharField()
    telephone = models.CharField(max_length=9)
    email = models.EmailField()
    teachers = models.ForeignKey(Teacher)

class Teacher(models.Model):
    name = models.CharField(max_length=50)
    direction = models.CharField(max_length=150)
    city = models.CharField(max_length=50)
    telephone = models.CharField(max_length=9)
    email = models.EmailField()
    students = models.ForeignKey(Student)

class Academy(models.Model):
    name = models.CharField(max_length=50)
    direction = models.CharField(max_length=150)
    city = models.CharField(max_length=50)
    teacher = models.ForeignKey(Teacher, blank=True, null=True)
    students = models.ForeignKey(Student)

问题是如果我实现第一个Student，没有找到老师来制作外键，如果我实现第一个Teacher，也是一样。

有什么方法可以在像 C 中的函数一样实现模型之前定义它们？

谢谢！

Answer 1

就在 Student 模型中将外键设置为 Teahcer 模型作为字符串：

teachers = models.ForeignKey('Teacher')

如前所述here：

If you need to create a relationship on a model that has not yet been defined, you can use the name of the model, rather than the model object itself

Django Models.py N对N的关系，总是说一个对象没有定义

Django Models.py N to N relationship, always says one object is not defined

django

django-models

foreign-key-relationship

cross-reference