Django：取消訂單時調整庫存的麻煩

Question

因此，在我的網站中，當用戶取消訂單時，我希望將用戶購買的產品的庫存帶回來，但是每當我測試它時，庫存都保持不變（但當用戶購買某物時會成功減少）。 我嘗試使用的函數是order/views.py 中的adjust_stock ，如下所示：

from django.shortcuts import render, get_object_or_404, redirect
from .models import OrderItem, Order
from cart.models import Cart, CartItem
from cart.views import _cart_id
from shop.models import Product
from django.core.exceptions import ObjectDoesNotExist
from django.contrib.auth.decorators import login_required
from datetime import datetime, timezone
from django.contrib import messages
from django.core.paginator import Paginator, EmptyPage, InvalidPage
import stripe

@login_required()
def order_create(request, total=0, cart_items = None):
    if request.method == 'POST':
        cart = Cart.objects.get(cart_id=_cart_id(request))
        cart_items = CartItem.objects.filter(cart=cart)
        for item in cart_items:
            total += (item.quantity * item.product.price)
        print('Total', total)
        charge = stripe.Charge.create(
            amount=str(int(total*100)),
            currency='EUR',
            description = 'Credit card charge',
            source=request.POST['stripeToken']
        )
    if request.user.is_authenticated:
        email = str(request.user.email)
        order_details = Order.objects.create(emailAddress = email)
        order_details.save()
    try:
        cart = Cart.objects.get(cart_id=_cart_id(request))
        cart_items = CartItem.objects.filter(cart=cart)
        for order_item in cart_items:
            oi = OrderItem.objects.create(
                product = order_item.product.name,
                quantity = order_item.quantity,
                price = order_item.product.price, 
                order = order_details)
        total += (order_item.quantity * order_item.product.price)
        oi.save()

        #Reduce stock when order is placed or saved
        products = Product.objects.get(id=order_item.product_id)
        if products.stock > 0:
            products.stock = int(order_item.product.stock - order_item.quantity)
        products.save()
        order_item.delete()
    except ObjectDoesNotExist:
        pass
    return render(request, 'order.html', dict(cart_items = cart_items, total=total))

def adjust_stock(id, quantity):
    products = Product.objects.filter(id=id)
    products.stock = int(product.stock + quantity)
    products.save()



@login_required()
def order_history(request):
    if request.user.is_authenticated:
        email = str(request.user.email)
        order_details = Order.objects.filter(emailAddress=email)
    paginator = Paginator(order_details, 3)
    try:
        page = int(request.GET.get('page', '1'))
    except:
        page = 1
    try:
        orders = paginator.page(page)
    except (EmptyPage, InvalidPage):
        orders = paginator.page(paginator.num_pages)
    return render(request, 'orders_list.html', {'orders':orders})




def cancel_order(request, order_id):
    order = get_object_or_404(Order, id=order_id)
    order_date = order.created
    current_date = datetime.now(timezone.utc)
    date_diff = current_date - order_date
    minutes_diff = date_diff.total_seconds() / 60.0
    order_items = OrderItem.objects.filter(id=order_id)
    if minutes_diff <= 30:
        for product in order_items:
            product.adjust_stock(order_items.product.id, order_items.quantity)



        order.delete()
        messages.add_message(request, messages.INFO,
                        'Your order is cancelled.')
    else:
        messages.add_message(request, messages.INFO,
                        'Sorry, it is too late to cancel this order.')
    return redirect('order_history')

如您所見，我在cancel_order函數中調用它，但它似乎不起作用。 任何幫助都將不勝感激！ 以下是相關代碼的其余部分：

訂單/models.py

from django.db import models
from shop.models import Product

class Order(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    emailAddress = models.EmailField(max_length=250, blank=True)

    class Meta:
        db_table = 'Order'
        ordering = ('-created', )

    def __str__(self):
        return 'Order {}'.format(self.id)

    def get_total_cost(self):
        return sum(item.get_cost() for item in self.items.all())

    def get_items(self):
        return OrderItem.objects.filter(order=self)

class OrderItem(models.Model):
    order = models.ForeignKey(Order, related_name='items', on_delete=models.CASCADE)
    product = models.CharField(max_length=250)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    quantity = models.PositiveIntegerField(default=1)

    def __str__(self):
        return '{}'.format(self.id)

    def get_cost(self):
        return self.price * self.quantity

購物車/models.py

from django.db import models
from shop.models import Product

class Cart(models.Model):
    cart_id = models.CharField(max_length=250, blank = True)
    date_added = models.DateField(auto_now_add=True)
    class Meta:
        db_table = 'Cart'
        ordering = ['date_added']

    def __str__(self):
        return self.cart_id

class CartItem(models.Model):
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    cart = models.ForeignKey(Cart, on_delete=models.CASCADE)
    quantity = models.IntegerField()
    class Meta:
        db_table = 'CartItem'

    def sub_total(self):
        return self.product.price * self.quantity

    def __str__(self):
        return self.product

購物車/views.py

from django.shortcuts import render, redirect, get_object_or_404
from shop.models import Product
from .models import Cart, CartItem
from django.contrib import messages
from django.core.exceptions import ObjectDoesNotExist
from django.conf import settings
import stripe

# Create your views here.
def _cart_id(request):
    cart = request.session.session_key
    if not cart:
        cart = request.session.create()
    return cart

def add_cart(request, product_id):
    product = Product.objects.get(id=product_id)
    try:
        cart = Cart.objects.get(cart_id=_cart_id(request))
    except Cart.DoesNotExist:
        cart = Cart.objects.create(
                cart_id = _cart_id(request)
            )
        cart.save()
    try:
        cart_item = CartItem.objects.get(product=product, cart=cart)
        if cart_item.quantity < cart_item.product.stock:
            cart_item.quantity += 1
            cart_item.save()
        else:
            messages.add_message(request, messages.INFO, 
                    'Sorry, no more of this item available')
    except CartItem.DoesNotExist:
        cart_item = CartItem.objects.create(
                    product = product,
                    quantity = 1,
                    cart = cart
            )
        cart_item.save()
    return redirect('cart_detail')

def cart_detail(request, total=0, counter=0, cart_items = None):
    try:
        cart = Cart.objects.get(cart_id=_cart_id(request))
        cart_items = CartItem.objects.filter(cart=cart)
        for cart_item in cart_items:
            total += (cart_item.product.price * cart_item.quantity)
            counter += cart_item.quantity
    except ObjectDoesNotExist:
        pass
    stripe.api_key = settings.STRIPE_SECRET_KEY
    stripe_total = int(total*100)
    description = 'MyTea - Order'
    data_key = settings.STRIPE_PUBLISHABLE_KEY
    return render(request, 'cart.html', dict(cart_items = cart_items, total = total, 
                    counter = counter, data_key = data_key, stripe_total = stripe_total, description = description))

def cart_remove(request, product_id):
    cart = Cart.objects.get(cart_id=_cart_id(request))
    product = get_object_or_404(Product, id=product_id)
    cart_item = CartItem.objects.get(product=product, cart=cart)
    if cart_item.quantity > 1:
        cart_item.quantity -= 1
        cart_item.save()
    else:
        cart_item.delete()
    return redirect('cart_detail')

def full_remove(request):
    cart = Cart.objects.get(cart_id=_cart_id(request))
    cart_items = CartItem.objects.filter(cart=cart)
    for cart_item in cart_items:
        cart_item.delete()
    return redirect('cart_detail')

謝謝！

Answer 1

products = Product.objects.filter(id=id) 應該是 product = Product.objects.get(id=id)

查詢集上的調用股票屬性應該在您的請求中引發錯誤？