Django 详细视图：在详细视图中从另一个模型中检索数据

Question

我正在尝试显示给定“项目”的关联“集团类”列表，但无法正确获取循环模板。我还想更进一步，只附加与项目关联的类（基于外键）

我已经尝试了一段时间，但到目前为止还没有任何运气，尤其是在模板方面！

Models.py

class Item(models.Model):
    title = models.CharField(max_length=100)
    price = models.FloatField()
    discount_price = models.FloatField(blank=True, null=True)
    category = models.CharField(choices=CATEGORY_CHOICES, max_length=2)
    label = models.CharField(choices=LABEL_CHOICES, max_length=1)
    slug = models.SlugField()
    description = models.TextField()
    image = models.ImageField()

    def save(self, *args, **kwargs):
    ...

    def __str__(self):
        return self.title
    ...

class CliqueClass(models.Model):
    title = models.CharField(max_length=100)
    start_date = models.DateTimeField(auto_now_add=True)
    end_date = models.DateTimeField(auto_now_add=True)
    item = models.ForeignKey(Item, related_name='items',
                             on_delete=models.CASCADE)
    description = models.TextField()
    plan = models.TextField()
    slug = models.SlugField()
    image = models.ImageField()

    def save(self, *args, **kwargs):
    ...

    def __str__(self):
    ...

My Views.py

class ItemDetailView(DetailView):
    model = Item
    template_name = "clique.html"
    # queryset = CliqueClass.objects.filter(title=Item.title)

    def get_context_data(self, **kwargs):
        """
        This has been overridden to add `cliqueclass` to the template context,
        now you can use {{ cliqueclass }} within the template
        """
        context = super().get_context_data(**kwargs)
        context['cliqueclass'] = CliqueClass.objects.all()
        return context

我的网址的.py

path('clique/<slug>/', ItemDetailView.as_view(), name='clique'),

我的 clique.html 模板：

 {% for class in object.cliqueclass_set.all %}
  <!--Look through all cliques classes-->
  <div class="mb-3">
    <a href="">
      <span>{{ class }}</span>
      <span class="badge purple mr-1">{{ class.title }}</span>

      <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Natus suscipit modi sapiente illo soluta odit
        voluptates,
        quibusdam officia. Neque quibusdam quas a quis porro? Molestias illo neque eum in laborum.</p>

    </a>
  </div>

  <hr class="solid">
  {% endfor %}

任何帮助将不胜感激:)

Answer 1

首先，你需要更改FK的related_name

class CliqueClass(models.Model):
    # rest of your code
    item = models.ForeignKey(Item, related_name='clique_classes',
                             on_delete=models.CASCADE)

related_name 可以是任意名称，但是，我认为clique_classes 是更合适的名称。

如果您不熟悉related_name，请阅读更多

1. What is related_name in Django -- (SO Post)

2. Following backwards relationship -- (Django doc)

3. ForeignKey.related_name -- (Django doc)

更改related_name后，需要执行以下命令迁移数据库，

1. python manage.py makemigrations
2. python manage.py migrate

然后，在您看来，删除 get_context_data(...) 方法，因为它与此特定问题无关。

class ItemDetailView(DetailView):
    model = Item
    template_name = "clique.html"

然后，将模板代码改为

{% for clique_class in object.clique_classes.all %}
    {{ clique_class.title }}
{% endfor %}