def create_transaction(request, product_id): purchase = Purchase() product = Product.objects.get(pk=product_id) purchase.product_id = product if request.method == 'POST': purchase.buyer_name = request.POST.get("name", "") purchase.quantity = request.POST.get("quantity", "") purchase.buyer_phone_number = request.POST.get("telephone", "") purchase.buyer_location = request.POST.get("location", "") purchase.product_id = Product.objects.get(pk=product_id) purchase.save() product.quantity = product.quantity - int(purchase.quantity) product.save() return redirect('home') return render(request, 'core/purchase/create_transaction.html', {'purchase': purchase});