如何从 Django 中的外键 model 获取属性？

Question

I have three models, item, variation and item_variations. The item has a foreignkey relation with variation, which in turn have a foreignkey relation with ItemVariation model. My question is, how do I access the attributes of Item variation to get hold of dynamic data by using the model Item. But I'm not being able to do so. Can anyone please help me with this?

My models.py:

class Item(models.Model):
    title = models.CharField(max_length=120)
    price = models.FloatField()

class Variation(models.Model):
    item = models.ForeignKey(Item, on_delete=models.CASCADE)
    name = models.CharField(max_length=50) # size, color

class ItemVariation(models.Model):
    variation  = models.ForeignKey(Variation, on_delete=models.CASCADE)
    value = models.CharField(max_length=50) # small, medium large etc

My admin.py:

class ItemVariationAdmin(admin.ModelAdmin):
    list_display = ['variation',
                    'value']

    list_filter = ['variation', 'variation__item']
    search_fields = ['value']


class ItemVariationInLineAdmin(admin.TabularInline):
    model = ItemVariation
    extra = 1


class VariationAdmin(admin.ModelAdmin):
    list_display = ['item',
                    'name']
    list_filter = ['item']
    search_fields = ['name']
    inlines = [ItemVariationInLineAdmin]


admin.site.register(ItemVariation, ItemVariationAdmin)
admin.site.register(Variation, VariationAdmin)

My views.py:

class ItemDetailView(DetailView):
    model = Item
    template_name = 'products/product.html'

My product.html:

<h1 class="product-title">{{ item.title }}</h1>
                  <a href="#">
                    <span class="badge purple mr-1">{{ object.get_category_display }}</span>
                  </a> 
<form class="form" method="POST" action="{{ object.get_add_to_cart_url }}">
                    {% csrf_token %}
                    {% if object.itemvariation_set.all %}

                      <h5>{{ object.itemvariation_set.all }}</h5>
                    {% endif %}
                    <div class="action">
                      <button class="btn btn-success">Add to Cart</button>
                    </div>
                  </form>

Answer 1

this way you can display item variation set

{% for var in object.variation_set.all %}
 <h5>{{ var.name }}</h5>
{% for item in var.itemvariation_set.all %}
 <h5>{{ item.value }}</h5>
{% endfor %}{% endfor %}