当我们在Django中搜索某些产品时如何进行产品排序？

Question

views.py：-

def search(request):
global pro
global products
if not request.GET.get('price_filter') == '1' or request.GET.get('price_filter') == '2':
    q = request.GET.get("q")
    products = Product.objects.filter(active=True, name__icontains=q)
    categories = Category.objects.filter(active=True)
    brands = Brand.objects.filter(active=True)
    context = {"products": products,
               "categories": categories,
                "brands": brands,
                "title": q + " - search"}
    return render(request, "shop/home.html", context)
pro = products

if request.GET.get('price_filter') == '1':
    products = pro.order_by('price')
    categories = Category.objects.filter(active=True)
    brands = Brand.objects.filter(active=True)
    context = {"products": products,
               "categories": categories,
               "brands": brands}
    return render(request, "shop/home.html", context)

elif request.GET.get('price_filter') == '2':
    products = pro.order_by('-price')
    categories = Category.objects.filter(active=True)
    brands = Brand.objects.filter(active=True)
    context = {"products": products,
               "categories": categories,
               "brands": brands}
    return render(request, "shop/home.html", context)

在HTML中：-

<form method='get' action='#' style="margin-top:-20px; margin-left: 8px;">
        <input class="btn btn-outline-dark" type="checkbox" value="1" name="price_filter"/>Low to High

        <input class="btn btn-outline-dark" type="checkbox" value="2" name="price_filter"/>High to Low
        <button class="btn" type="submit" value="Sort">Sort</button>
    </form>

使用该搜索，我们可以从低到高排序，但是当我选择从高到低时，它会显示某些错误：-

Cannot use None as a query value

我知道这不是执行此操作的正确方法，但是可以帮助我解决此问题，或者为我提供正确的排序方法。

Answer 1

此行发生此错误：

if not request.GET.get('price_filter') == '1' or request.GET.get('price_filter') == '2':
                                                ^^^

表示如果没有request.GET.get('price_filter')的值而有request.GET.get('price_filter')的值。我认为这里应该是这样的not子句：

if not request.GET.get('price_filter') == '1' or not request.GET.get('price_filter') == '2':
                                                 ^^^

原因是，模板中没有q的输入字段。

此外，您也可以将querystring值存储在变量中，以使该代码更清晰：

price_filter = request.GET.get('price_filter')

if price_filter not in ["1", "2"]:
    q = request.GET.get("q")
    # rest of the code
elif price_filter == "1":
    # more code
elif price_filter == "2":
    # more code