AttributeError, 'AnimalType' 没有属性 'animals_set'

Question

由于某种原因，我收到了一个 AttributeError 。“'动物类型'没有属性'animals_set'”这是它所指的模型：

class AnimalType(models.Model):

    """Type of animal that can classify the animal"""

    owner = models.ForeignKey(User, on_delete=models.CASCADE)

    a_type = models.CharField(max_length=50, default='')

    date_added = models.DateField(auto_now_add=True)

    def __str__(self):

        return self.a_type

class Animal(models.Model):

    """The actual animal, embeded in animaltype"""

    animal_type = models.ForeignKey(AnimalType, on_delete=models.CASCADE)

    name = models.CharField(max_length=60, default='')

    date_added = models.DateField(auto_now_add=True)

    def __str__(self):

        if len(self.name)>20:

            return self.name[:20] + "..."

        else:

            return self.name

这是它正在执行的函数：

@login_required

def animal_type(request, animal_type_id):

    """Shows a single animal type and all of the animals associated"""

    animal_type = AnimalType.objects.get(id=animal_type_id)

    #animal type belongs to user

    if animal_type.owner != request.user:

        raise Http404

    animals = animal_type.animals_set.order_by('-date_added')

    context = {'animal_type':animal_type, 'animals':animals}

    return render(request, 'zoo_animal_feeders/animal_type.html', context)

Answer 1

related_name这种情况下的默认值是animal_set。我建议始终related_name在您的关系字段中进行设置以避免这种混淆。