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

我知道这不是正确的方法，但请帮我解决这个问题，或指导我正确的排序方法。

Answer 1

此行出现此错误：

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

它指出如果没有request.GET.get('price_filter') 的值并且有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，您的模板中没有 q 的输入字段。

此外，您可以将查询字符串值存储在变量中以使这段代码更简洁：

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

Answer 2

你应该尝试我给出的代码

def search(request):
    price_filter = request.GET.get('price_filter',None) 
    context = {}
    if price_filter not in '12': 
        q = request.GET.get("q")
        products = Product.objects.filter(active=True, name__icontains=q)
        context = {"title": q + " - search"}

    if price_filter == '1':
        pro = Product.objects.filter(active=True, name__icontains=q) if request.GET.get("q",None) else  Product.objects.filter(active=True)
        products = pro.order_by('price')

    elif price_filter == '2':
        pro = Product.objects.filter(active=True, name__icontains=q) if request.GET.get("q",None) else  Product.objects.filter(active=True)
        products = pro.order_by('-price')



    categories = Category.objects.filter(active=True)
    brands = Brand.objects.filter(active=True)               
    context =context.update({"products": products,
                   "categories": categories,
                    "brands": brands})               
    return render(request, "shop/home.html", context)

如果遇到或使用这些东西有任何问题，请告诉我

Answer 3

在视图中我改变了这个，现在它工作得很好：-

views.py

def search(request):
global pro
global products
if request.GET.get('price_filter') not in ["1", "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)