Haystack SearchQuerySet使用内容过滤器返回None

我有以下SearchIndex:

class ProductIndex(indexes.SearchIndex, indexes.Indexable):
    text = indexes.CharField(document=True)
    display_name = indexes.CharField(model_attr='display_name')
    link = indexes.CharField(model_attr='link')

    def get_model(self):
        return Product

    def index_queryset(self, using=None):
        """Used when the entire index for model is updated."""
        return self.get_model().objects.\
                    filter(last_updated__lte=datetime.datetime.now())

它可以很好地处理以下查询:

 >>>> SearchQuerySet().filter(display_name='Levis jeans')
 [<SearchResult ... >, <SearchResult ... >, ...]

但当我使用任何内容过滤器时,它都会返回空列表:

 >>>> SearchQuerySet().filter(content='Levis jeans')
 []

此外,没有带有的solr Docs text 领域