DRF annotated queryset filtering with django-filter

Question

can anyone help with filtering in DRF. I have some products models, say Product and manager ProductManager:

class ProductItem(Model):
    price = DecimalField()

class Product(Model):
    items = ManyToManyField(ProductItem)
    priceman = ProductManager()

class ProductManager(Manager):
    def get_queryset(self):
        qs = super().get_queryset().annotate(total_price=Sum('items__price'))
    return qs

Here if filter class:

class ProductFilter(django_filters.rest_framework.FilterSet):
    class Meta:
        model = Product
        fields = {
            'total_price': ['lt', 'gt'],
        }

Here is view:

class ProductViewSet(ModelViewSet):
    queryset = Product.priceman.all()
    filterset_class = ProductFilter

and I get the error:

TypeError: 'Meta.fields' contains fields that are not defined on this FilterSet: total_price

How should I configure the filter class to make this work?

score 2 · Answer 1 · answered Oct 30 '18 at 12:17

I found answer, this can be done by changing filter class like this:

class ProductFilter(django_filters.rest_framework.FilterSet):
    min_price = NumberFilter(field_name="total_price", lookup_expr='gt')
    max_price = NumberFilter(field_name="total_price", lookup_expr='lt')
    class Meta:
        model = Product
        fields = ['min_price', 'max_price']

DRF annotated queryset filtering with django-filter

1 Answers1