Django模型在其他模型上的继承'；s场

我有以下型号：

class Engine(models.Model):
    ...
    def speed(self):
        return 100
    objects = InheritanceManager()

class TurboEngine(Engine):
    ...
    def speed(self):
        return 500

class Car(models.Model):
    ...
    engine = models.ForeignKey(Engine)

---

不，我正在使用带有

涡轮发动机的
汽车
的详细视图，但是
汽车.engine.speed（）
返回100。如何选择合适的课程？
这是一个非常有趣的问题，我们在两三年前遇到过同样的问题：

class RealInstaceProvider(object):
    def get_real_instance(self):
        """
        Makes a SQL sentence which does the JOIN with its real model class
        """

        if hasattr(self, '_real_instance'):  # try looking in our cache
            return self._real_instance
        subclasses = self.__class__.__subclasses__()
        if not subclasses:  # already real_instance
            real_instance = getattr(self, self.__class__.__name__, self)
            self._real_instance = real_instance
            return real_instance
        else:
            subclasses_names = [cls.__name__.lower() for cls in subclasses]
            for subcls_name in subclasses_names:
                if hasattr(self, subcls_name):
                    self._real_instance = getattr(self, subcls_name, self).get_real_instance()
                    return self._real_instance
            self._real_instance = self
            return self

class Engine(models.Model, RealInstaceProvider):
    ...
    def speed(self):
        return 100
    objects = InheritanceManager()

class TurboEngine(Engine):
    ...
    def speed(self):
        return 500

class Car(models.Model):
    ...
    engine = models.ForeignKey(Engine)

您必须访问下一种方式：car.engine.get\u real\u provider（）.speed（）
谢谢，这只需要做一些小改动：self.\uuuuu class.\uuuu.get\u subclass（）应该是self.\uuuu class.\uuu subclass.\uuu子类和self.class\uu名称应该是self.\uuuuu class.\uu好的，我为您复制、粘贴和概括了，我会编辑我的回答我相信我不需要这个
objects=InheritanceManager（）
，对吗？是的，我想你不需要这个