如何将序列化程序中的字段获取到 ListView 中进行过滤

Question

the model in question:

class CustomerPrices(models.Model):
    url = models.OneToOneField('CustomerProductUrls', models.DO_NOTHING, db_column="url", primary_key=True)
    written = models.DateTimeField()
    reseller = models.CharField(max_length=250)
    price = models.FloatField(blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'customer_prices'
        unique_together = (('url', 'written', 'reseller'),)

the serializer (and one related serializer) in question:

class CustomerProductUrlsSerializer(serializers.ModelSerializer):
    ean = CustomerProductsSerializer()
    url = serializers.CharField(max_length=255, required=False)
    class Meta:
        model = CustomerProductUrls
        fields = '__all__'

class CustomerPricesSerializer(serializers.ModelSerializer):
    written = serializers.DateTimeField(format='%Y-%m-%d %H:%M:00', required=False)
    reseller = serializers.CharField(max_length=250, required=False)
    url = CustomerProductUrlsSerializer()
    name = serializers.SerializerMethodField('get_name')
    ean = serializers.SerializerMethodField('get_ean')
    url = serializers.SerializerMethodField('get_url')
    price = serializers.FloatField()

    class Meta:
        model = CustomerPrices
        fields = '__all__'

    def get_name(self, obj):
        return obj.url.ean.name

    def get_ean(self, obj):
        return obj.url.ean.ean

    def get_url(self, obj):
        return obj.url.url

and the ListAPIView for the CustomerPrices class:

class CustomerPricesListView(generics.ListAPIView):
    serializer_class = CustomerPricesSerializer
    filter_backends = (DjangoFilterBackend, OrderingFilter)
    fields = ('written', 'url', 'price')
    filter_fields = fields
    search_fields = fields
    def get_queryset(self):
        """
        This view should return a list of all the products where price >= 70
        """
        return CustomerPrices.objects.filter(price__gte=70)

Inside my CustomerPricesSerializer I've got a field named ean as well as name the values for these two come through the related CustomerProductUrlsSerializer (and corresponding model). The code is working so far, I get a response looking like this:

"results": [
    {
        "url": "https://www.example.com/p/12345678",
        "written": "2020-04-05 12:00:00",
        "reseller": "ABC123",
        "name": "Product 12345678",
        "ean": "1234567890123",
        "price": 98.3
    }, ... 
    ]

I'm using the DjangoFilterBackend and I would like to filter on the ean as well as the name , which is available in my response. But as soon as I add ean to my fields tupel inside the Serializer I get the Meta.fields contains fields that are not defined on this FilterSet: ean . I do understand that my queryset is returning the fields from CustomerPrices Model inside my ListAPIView, but how do I get get the ean as well as the name to be a part of the queryset and therefore a part of the available fields

Answer 1

The field ean does not belong to the CustomerPrices model but somewhere else. The DRF expects the filter tuples are directly related to the model (here CustomerPrices ) and hence the error.

To resolve this issue, you have to provide the actual relationship to the ean field.

class CustomerPricesListView(generics.ListAPIView):
    fields = ('written', 'url', 'price', )
    filter_fields = fields
    # rest of the code