Python 使用.filter（）返回多个对象？

我正在编写一个自定义身份验证后端，用于将legacyusers迁移到运行在django 1.3.1上的新django站点。 我必须这样做的原因有两个，一个是使用非唯一电子邮件地址对用户进行身份验证。我只有他们密码的md5散列

我有一个名为LegacyUser的模型，其字段名为login_email和login_password（来自旧数据库设计）

以下是我的身份验证后端：

from django.contrib.auth.models import User, check_password
from webshipping.accounts.models import LegacyUser, UserProfile
from hashlib import md5

# see https://docs.djangoproject.com/en/1.3/topics/auth/
# and http://query7.com/django-authentication-backends
class AccountBackend:
    supports_object_permissions = False
    supports_anonymous_user = False
    supports_inactive_user = False

    def authenticate(self, username=None, password=None):
        users = User.objects.filter(email=username)
        for user in users:
            pwd_valid = check_password(password, user.password)
            if pwd_valid:
                return user
        try:
            md5hash = md5(password).hexdigest()
            lu = LegacyUser.objects.filter(login_email=username).filter(login_password=md5hash)
            if lu == []:
                return None

            user = User.objects.create_user(lu[0].login_email, lu[0].login_email, password)
            (first, sep, last) = lu[0].login_realname.rpartition(" ");
            user.first_name = first
            user.last_name = last
            p = user.get_profile()
            p.language = lu[0].login_language
            p.save()
            user.save()
            return user

        except LegacyUser.DoesNotExist:
            return None

    def get_user(self, user_id):
        try:
            return User.objects.get(pk=user_id)
        except User.DoesNotExist:
            return None

问题是当我打电话的时候

LegacyUser.objects.filter(login_email=username).filter(login_password=md5hash) 

它抛出：

get() returned more than one LegacyUser -- it returned 3! Lookup parameters were {'login_email': u'test'}

这正是我想要它做的，我想要所有的LegacyUser实例与这个特定的电子邮件和密码组合，这样我就可以将它们组合成一个新的django用户

如果我刷新页面2-3次，它就会通过并创建用户对象，所有未来的登录都会按预期工作

我的问题是，我错过了什么？过滤器不应该返回多个对象吗

以下是完整的回溯：

Environment:


Request Method: POST
Request URL: http://192.168.100.65/accounts/login/?next=/

Django Version: 1.3.1
Python Version: 2.7.2
Installed Applications:
['django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django_extensions',
 'webshipping.accounts',
 'webshipping.addressbooks',
 'webshipping.shipments',
 'webshipping.transports']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware')


Traceback:
File "/usr/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/usr/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapped_view
  93.                     response = view_func(request, *args, **kwargs)
File "/usr/lib/python2.7/dist-packages/django/views/decorators/cache.py" in _wrapped_view_func
  79.         response = view_func(request, *args, **kwargs)
File "/usr/lib/python2.7/dist-packages/django/contrib/auth/views.py" in login
  35.         if form.is_valid():
File "/usr/lib/python2.7/dist-packages/django/forms/forms.py" in is_valid
  121.         return self.is_bound and not bool(self.errors)
File "/usr/lib/python2.7/dist-packages/django/forms/forms.py" in _get_errors
  112.             self.full_clean()
File "/usr/lib/python2.7/dist-packages/django/forms/forms.py" in full_clean
  268.         self._clean_form()
File "/usr/lib/python2.7/dist-packages/django/forms/forms.py" in _clean_form
  296.             self.cleaned_data = self.clean()
File "/usr/lib/python2.7/dist-packages/django/contrib/auth/forms.py" in clean
  85.             self.user_cache = authenticate(username=username, password=password)
File "/usr/lib/python2.7/dist-packages/django/contrib/auth/__init__.py" in authenticate
  55.             user = backend.authenticate(**credentials)
File "/usr/local/lib/link/dev/webshipping/../webshipping/accounts/backends.py" in authenticate
  20.                     lu = LegacyUser.objects.filter(login_email=username).filter(login_password=md5hash)
File "/usr/lib/python2.7/dist-packages/django/db/models/manager.py" in get
  132.         return self.get_query_set().get(*args, **kwargs)
File "/usr/lib/python2.7/dist-packages/django/db/models/query.py" in get
  351.                 % (self.model._meta.object_name, num, kwargs))

Exception Type: MultipleObjectsReturned at /accounts/login/
Exception Value: get() returned more than one LegacyUser -- it returned 3! Lookup parameters were {'login_email': u'test'}

---

我不确定，但您的错误消息说，

LegacyUser

有3个实例具有相同的“登录电子邮件”。现在你说你想“组合”他们的密码。这是否意味着您将允许使用3个密码中的任何一个登录到此帐户？您是否计划在数据库中使用列表/数组作为密码字段？我有一个旧网站，我想迁移该网站的用户。用户被绑定到多个组中，每个组成员在

LegacyUser

中都有记录。因此，每个

LegacyUser

login\u电子邮件都是非唯一的，每个用户都通过电子邮件和密码进行标识。所以我希望所有3个（密码相同）都是一个用户。这实际上似乎是服务器与代码不同步。您最初是否编写了

get

，然后将其更改为

filter

？如果是这样，请删除所有

.pyc

文件并重新启动服务器。我认为你是对的。。。我想我发现了这个问题，我正在通过mod_wsgi在apache上运行这个站点。。apache/mod_wsgi似乎存储了站点的某种缓存。正如我重新启动apache时一样，它自己解决了问题。除非您要求，否则mod_wsgi不会使用新代码。您可以触摸.wsgi文件（首选方式）或重新启动Apache。