在视图中定义get_queryset，属性错误

Question

我正在尝试编写自定义 get_queryset 函数，因为我想从“request.user.email”访问用户的电子邮件，并使用它来形成另一个查询，我想使用我的视图 @987654323 显示@。第一次在这里问问题，搜索了网站，但没有找到类似的东西，但如果你确实找到了东西，直接告诉我，我会尽快删除这个

环境：

Request Method: GET
Request URL: http://192.168.24.169:8000/products/cart/

    Django Version: 3.1.2
    Python Version: 3.6.9
    Installed Applications:
    ['products.apps.ProductsConfig',
     'accounts.apps.AccountsConfig',
     'django.contrib.admin',
     'django.contrib.auth',
     'django.contrib.contenttypes',
     'django.contrib.sessions',
     'django.contrib.messages',
     'django.contrib.staticfiles']
    Installed Middleware:
    ['django.middleware.security.SecurityMiddleware',
     '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 (most recent call last):
  File "/home/nirman/.local/lib/python3.6/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/home/nirman/.local/lib/python3.6/site-packages/django/core/handlers/base.py", line 179, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/nirman/.local/lib/python3.6/site-packages/django/views/generic/base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/nirman/.local/lib/python3.6/site-packages/django/views/generic/base.py", line 98, in dispatch
    return handler(request, *args, **kwargs)
  File "/home/nirman/.local/lib/python3.6/site-packages/django/views/generic/list.py", line 142, in get
    self.object_list = self.get_queryset()
  File "/home/nirman/Desktop/login/products/views.py", line 91, in get_queryset
    self.user = request.user

Exception Type: AttributeError at /products/cart/
Exception Value: 'cartv' object has no attribute 'user'

观看次数：

class cartv(generic.ListView):
    model = cart
    context_object_name = 'cart_list'   
    template_name='products/cartview.html'

    def get_queryset(request):
        qs = cart.objects.filter(user__email=request.user.email) #error points here
        if qs.exists():
            c = qs[0]
            return c.items.all()

        else:
            return redirect('failure')

型号：

class cart_item(models.Model): 
products = models.ManyToManyField(product) 
quantity = models.IntegerField(null=False, default=1) 
user = models.ManyToManyField(User) 

class cart(models.Model): 
items = models.ManyToManyField(cart_item) 
user = models.ManyToManyField(User) 
ordered = models.BooleanField(null=False, default=False)

Answer 1

您应该将self 参数传递给get_queryset 方法。然后，在self 参数中，您可以通过self.request 访问request。

在你的情况下应该是这样的：

class cartv(generic.ListView):
    model = cart
    context_object_name = 'cart_list'   
    template_name='products/cartview.html'

    def get_queryset(self):
        qs = cart.objects.filter(user__email=self.request.user.email)
        if qs.exists():
            c = qs[0]
            return c.items.all()

        else:
            return redirect('failure')

Answer 2

get_queryset(…) method [Django-doc] 不带参数request，它有一个参数self（与任何对象方法一样）。

此外，redirect 在这种情况下将不起作用。 get_queryset 应该返回 QuerySet，而不是 redirect。例如，在这种情况下，您可以引发 Http404 异常：

from django.http import Http404

class cartv(generic.ListView):
    model = cart_item
    context_object_name = 'cart_list'   
    template_name='products/cartview.html'

    def get_queryset(self):
        cart = cart.objects.filter(user=self.request.user)
        try:
            cart[0].items.all()
        except IndexError:
            raise Http404

然而，首先使用cart[0] 有点“奇怪”。如果用户有多个购物车，那为什么要退回第一个？