Django AttributeError：模型对象没有属性'filter'。

Question

我正在尝试使用Django创建自己的博客。我有一个视图来显示一篇文章，该视图是从DetailView扩展而来的。 为了避免与slug相关的任何问题，我正在尝试使用文章的发布日期对其进行分类。一篇文章的url如下（其中pk对应于文章的slug）：

r'articles/(?P<year>\d{4})/(?P<month>\d{2})/(?P<day>\d{2})/(?P<pk>[\w-]+)/$'

依我之见，我想要做这件事：

def get_queryset(self):
    year = self.kwargs.get("year", None)
    month = self.kwargs.get("month", None)
    day = self.kwargs.get("day", None)

    publication_date = year + "-" + month + "-" + day

    return Article.objects.get(created_at__startswith=publication_date, slug=self.kwargs.get("pk", None))

但它不起作用，我不明白......实际上，当我这样做时，它就起作用了：

return Article.objects.filter(created_at__startswith=publication_date, slug=self.kwargs.get("pk", None))

但它返回一个QuerySet，而我只想要一篇文章！([0]返回相同的错误)

这是错误信息:

AttributeError at /articles/2015/03/04/nouveau-site/
'Article' object has no attribute 'filter'
Django Version: 1.6.2
Exception Location: C:\Python27\lib\site-packages\django\views\generic\detail.py in get_object, line 37
Python Version: 2.7.6

完整的回溯信息如下：

Environment:


Request Method: GET
Request URL: http://localhost:8000/articles/2015/03/04/nouveau-site/

Django Version: 1.6.2
Python Version: 2.7.6
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'groups',
 'posts',
 'users')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Traceback:
File "C:\Python27\lib\site-packages\django\core\handlers\base.py" in get_response
  114.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Python27\lib\site-packages\django\views\generic\base.py" in view
  69.             return self.dispatch(request, *args, **kwargs)
File "C:\Python27\lib\site-packages\django\views\generic\base.py" in dispatch
  87.         return handler(request, *args, **kwargs)
File "C:\Python27\lib\site-packages\django\views\generic\detail.py" in get
  110.         self.object = self.get_object()
File "C:\Python27\lib\site-packages\django\views\generic\detail.py" in get_object
  37.             queryset = queryset.filter(pk=pk)

Exception Type: AttributeError at /articles/2015/03/04/nouveau-site/
Exception Value: 'Article' object has no attribute 'filter'

提前致谢！

- Yann Bertrand

---

问题是：.get()返回一个模型对象，而get_queryset期望返回一个queryset。因此出现了错误。 - karthikr

Answer 1

def get_queryset(self):
    ...

    return Article.objects.filter(created_at__startswith=publication_date, slug=self.kwargs.get("pk", None))

由于get_queryset必须返回QuerySet对象，而不是模型对象。

- Andrey Nelubin

Answer 2

你还可以使用 get_object()。

def get_object(self):
    ...

    return Article.objects.get(created_at__startswith=publication_date, slug=self.kwargs.get("pk", None))

- mohammad