有关Django自定义身份验证和登录的错误？

我为登录系统创建了一个自定义身份验证后端。当然，当我在python shell中尝试该自定义后端时，它可以工作。但是，在服务器中运行它时出现错误。错误消息为“以下字段在此模型中不存在，或者为m2m字段：last_login”。我是否需要在客户模型中包含last_login字段，或者是否有其他解决方案来解决该问题？这是我的示例代码：

In my models.py

class Customer(models.Model):

  yes_or_no = ((True, 'Yes'),(False, 'No'))
  male_or_female = ((True,'Male'),(False,'Female'))

  name = models.CharField(max_length=100)
  email = models.EmailField(max_length=100,blank = False, null = False)
  password = models.CharField(max_length=100)
  gender = models.BooleanField(default = True, choices = male_or_female)
  birthday = models.DateField(default =None,blank = False, null = False)
  created = models.DateTimeField(default=datetime.now, blank=True)
  _is_active = models.BooleanField(default = False,db_column="is_active")

  @property
  def is_active(self):
    return self._is_active
  # how to call setter method, how to pass value ?
  @is_active.setter
  def is_active(self,value):
    self._is_active = value

  def __str__(self):
    return self.name

在backends.py中

from .models import Customer
from django.conf import settings

class CustomerAuthBackend(object):

    def authenticate(self, name=None, password=None):
        try:
            user = Customer.objects.get(name=name)

            if password == getattr(user,'password'):
                # Authentication success by returning the user
                user.is_active = True
                return user
            else:
                # Authentication fails if None is returned
                return None
        except Customer.DoesNotExist:
            return None

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

在views.py中

@login_required(login_url='/dataInfo/login/')
def login_view(request):
    if request.method == 'POST':

        username = request.POST['username']
        password = request.POST['password']
        user = authenticate(name=username,password=password)
        if user is not None:

            if user.is_active:
                login(request,user)
                #redirect to user profile
                print "suffcessful login!"
                return HttpResponseRedirect('/dataInfo/userprofile')
            else:
                # return a disable account
                return HttpResponse("User acount or password is incorrect")
        else:
            # Return an 'invalid login' error message.
            print "Invalid login details: {0}, {1}".format(username, password)
            # redirect to login page
            return HttpResponseRedirect('/dataInfo/login')
    else:

        login_form = LoginForm()
    return render_to_response('dataInfo/login.html', {'form': login_form}, context_instance=RequestContext(request))

在setting.py中

AUTHENTICATION_BACKENDS = ('dataInfo.backends.CustomerAuthBackend', 'django.contrib.auth.backends.ModelBackend',)