无法将关键字u'blanks'解析为字段。选择是：id，name，sort_order

Question

我已多次发布此问题，但无法找到解决问题的方法。

下面，我的代码在Django 1.6.3中运行良好，但在更新到1.9.6之后它无法正常工作，尽管我已经更新了所有依赖项并进行了所有数据库迁移。

我的错误是：

for color_group in blank.color_groups.all():

指向view.py

以下是我的代码

Model.py

class ColorGroup(models.Model):
    """Categorization for Colors"""
    name = models.CharField(max_length=100)
    sort_order = models.IntegerField()

    class Meta:
        ordering = ['sort_order']
        app_label='portal'

    def __unicode__(self):
        return self.name

class Blank(models.Model):
    """
    A particular instance of a printable item, such as the Black Men's 
    American Apparel 50/50 t-shirt.
    """
    image = models.ImageField(upload_to="blank_images", blank=True, validators=[validate_file_extension])
    color = models.CharField(max_length=100)
    style = models.ForeignKey(BlankStyle)
    is_featured = models.BooleanField(verbose_name="Featured?", default=False)
    color_groups = models.ManyToManyField(ColorGroup, related_name='blanks')

    def as_hash(self):
         image_url = ""
         if self.image:
             image_url = self.image.url

        return {
            'id': self.id,
            'color': self.color,
            'style_code': self.style.code,
            'style': self.style.as_hash(),
            'image_url': image_url,
            'sizes': [bs.as_hash() for bs in self.sizes.all()]
         }

    @property
    def image_url(self):
        if self.image:
            return self.image.url
        return None

    @property
    def public_thumbnail_url(self):
        from sorl.thumbnail import get_thumbnail
        if self.image:
            im = get_thumbnail(self.image, '58x58', crop='center',quality=99)
            return im.url
        return None

    @property
    def public_medium_url(self):
        from sorl.thumbnail import get_thumbnail
        if self.image:
            im = get_thumbnail(self.image, '382x456',quality=99)
            return im.url
        return None

    def __unicode__(self):
        return self.style.code + ": " + self.color


    class Meta:
        app_label = 'portal'

和view.py

def order_new_json_data(request,all=False):
    # Brands
    brands = Brand.objects.all()
    json_brands = serializers.serialize("json", brands)

    # Blanks
    blanks = Blank.objects.prefetch_related('style').filter(is_featured=True).order_by('style__id')

    # custom output
    blank_list = []
    for blank in blanks.all():
        color_groups = []
        for color_group in blank.color_groups.all():
            color_groups.append(color_group.pk)

回溯：

File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site- packages/django/core/handlers/base.py" in get_response 149. response = self.process_exception_by_middleware(e, request)
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response 147. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/utils/decorators.py" in _wrapped_view 149. response = view_func(request, *args, **kwargs)
File "/home/muhammad/Desktop/ClockwiseLatest/clockwise/public/orders/views.py" in order_new_json_data 356. for color_group in blank.color_groups.all():
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/manager.py" in all 223. return self.get_queryset()
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/fields/related_descriptors.py" in get_queryset 792. return qs._next_is_sticky().filter(**self.core_filters)
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/query.py" in filter 790. return self._filter_or_exclude(False, *args, **kwargs)
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/query.py" in _filter_or_exclude 808. clone.query.add_q(Q(*args, **kwargs))
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in add_q 1243. clause, _ = self._add_q(q_object, self.used_aliases)
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in _add_q 1269. allow_joins=allow_joins, split_subq=split_subq,
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in build_filter 1149. lookups, parts, reffed_expression = self.solve_lookup_type(arg)
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in solve_lookup_type 1035. _, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
File "/home/muhammad/Desktop/ClockwiseLatest/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in names_to_path 1330. "Choices are: %s" % (name, ", ".join(available)))

Exception Type: FieldError at /orders/new/json_data/
Exception Value: Cannot resolve keyword u'blanks' into field. Choices are: id, name, sort_order