Hi @stvdrsch

See #811 - you need to add by_alias=True :

@api.get('/dealers', response=list[DealerSchema], by_alias=True)
def dealers(request):
    return Dealer.objects.all()

to make this behaviour by default you can extend the Router and add by_alias as default:

from ninja import Router


class MyRouter(Router):
    def add_api_operation(self, *a, **kw):
           kw['by_alias'] = True
           return super().add_api_operation(*a, **kw)

...

router = MyRouter()

@router.get('/dealers', response=list[DealerSchema])
def dealers(request):
    return Dealer.objects.all()

Yes, that was added and the by_alias works for every other field. But the ForeignKey fields, and any other fields that use related models I would guess, still just outputs ..._id

In the response in the initial question fields like countryCode and postalCode are defined like country_code and postal_code in the original Django model and get correctly aliased. It's just the foreignkey id field that doesn't seem to pass through the alias_generator.

I think I have a solution for this. Let's say we have a django model and ninja schema like so

class Book(models.Model):
    id = models.AutoField(primary_key=True)
    full_name = models.CharField(max_length=100)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

class BookSchema(ModelSchema):
    model_config = dict(alias_generator=to_camel, populate_by_name=True)
    class Meta:
        model = Book
        fields = ["id", "full_name", "author"]

The ModelSchema metaclass factory currently creates fields for ForeignKeys with aliases that correspond with their Django field attribute name (author here gets an author_id alias). This is the reason why Pydantic fields mapping foreign keys need the alias at the moment and why there is a conflict with the alias_generator.

Instead, we could set the property names on the Pydantic model to match these field attribute names, so BookSchema.author would become BookSchema.author_id, and stop setting the alias on that field. Then, it will be aliased for the API if you do .model_dump(by_alias=True) and properly named for Django if you do .model_dump(by_alias=False).

This causes a new problem where users can no longer access the property by the field name as they would expect since it has been renamed (BookSchema.author is now at BookSchema.author_id instead). To solve this, we can additionally generate property functions to access through the expected name.

The final generated class would be equivalent to:

 class BookSchema(Schema):
    model_config = dict(alias_generator=to_camel, populate_by_name=True)
   
    id: int = Field(...)
    full_name: str = Field(...)  # generated alias "fullName"
    author_id: int = Field(...)  # generated alias "authorId"
    
    @property
    def author(self):
        return self.author_id

    @author.setter
    def author(self, value):
        self.author_id = value

How does this sound @vitalik ? If you're OK with this solution I can write a PR for it.