Django prefetch_related 输出 None

Question

我是 Django 的新手。我正在做一个简单的商店。目前我正在处理订单部分。每个订单中都有订单项目。每个订单商品都有一些值和一个产品 ID。

我想在 index.html 上显示的是其中的订单及其项目。但是 order.items 总是输出 order.OrderItem.None

views.py

class IndexView(generic.ListView):
    template_name = 'order/index.html'
    context_object_name = 'all_orders'

    def get_queryset(self):
        return Order.objects.all().prefetch_related('items')

    def get_context_data(self, **kwargs):
        context = super(IndexView, self).get_context_data(**kwargs)
        return context

views.py

# Create your models here.
class Order(models.Model):
    user = models.ForeignKey(User, related_name='orders')
    created_at = models.DateTimeField(auto_now_add=True, null=True)

class OrderItem(models.Model):
    product = models.ForeignKey(Product)
    order = models.ForeignKey(Order, related_name='items')
    item_name = models.CharField(max_length=255, null=True, blank=True)
    item_price_in_usd = models.DecimalField(max_digits=6, decimal_places=2, null=True, blank=True)

    def __str__(self):
        return self.product.name

index.html

{% for order in all_orders %}
        <tr>
            <td>{{ order}}</td>
            <td>{{ order.created_at}}</td>
            <td>{{ order.items}}</td>
        </tr>
    {% endfor %}

Answer 1

好的，我已经找到解决办法了。显然你必须添加 .all

{% for order in all_orders %}
        <tr>
            <td>{{ order}}</td>
            <td>{{ order.created_at}}</td>
            <td>
                {% for items in order.items.all %}
                    <td>{{ items.item_name}}</td>
                {% endfor %}
            </td>
        </tr>
    {% endfor %}

Django prefetch_related 输出 None

Django prefetch_related outputs None

python

django

django-1.11