Question

我在django中存储数据时遇到了麻烦。我附加一个元组，但每次我发一个帖子请求它都会显示一个空数组。它应该每次都附加？谁能让我知道为什么会这样？（我的表格和数据工作正常，信息在request.POST中收到）

views.py

会话在用户登录时启动

    def post(request):
    username = request.POST["username"]
    password = request.POST["password"]

    user = authenticate(username=username, password=password)

    if user is not None:
        login(request, user)
        request.session['cart'] = []
        return redirect("/")
    else:
        return render(request, 'sign_in.html', {
            "error": "Invalid Credentials"
        })

现在是

的问题所在

获取方法（基于类的视图）

 def get(request):
    stalls = available_stalls()
    products = Product.objects.all()

    if 'cart' not in request.session:
        request.session['cart'] = []
        cart_count = 0
    else:
        cart_count = len(request.session['cart'])

    context = {
        "stalls": stalls,
        "products": products,
        'cart_count': cart_count
    }

    if request.user.is_authenticated:
        user = request.user
        customer = Customer.objects.filter(user=user)[0]
        full_name = customer.full_name
        context["name"] = full_name

    return render(request, 'product_catalog.html', context)

post方法（基于类的视图）

    def post(request):

    if "product" not in request.POST or "quantity" not in request.POST:
        raise Http404("Product or quantity not in POST data")

    product_id = request.POST["product"]
    quantity = request.POST["quantity"]

    try:
        product = Product.objects.get(id=product_id)
    except:
        raise Http404("Product ID not in database")


    print(request.session["cart"])
    request.session["cart"].append((product, quantity))
    cart_count = len(request.session['cart'])


    stalls = available_stalls()
    products = Product.objects.all()

    # TODO: Compute recommendations
    return render(request, 'product_catalog.html', {
        'added_to_cart': product,
        'cart_count': cart_count,
        'quantity': quantity,
        'stalls': stalls,
        'products': products
    })

Answer 1

when sessions are saved上的文档解释了这一点。基本上，会话仅在修改其中一个顶级键时自动保存。但是您要在会话中的现有列表中添加元素。您需要明确说出request.session.modified = True来触发保存。

存储在会话中的信息不保存django

1 个答案: