def _model_fields(self, model: Type[Model]) -> Iterator[DjangoField]:
        "returns iterator with all the fields that can be part of schema"
        for fld in model._meta.get_fields():
            if isinstance(fld, (ManyToOneRel, ManyToManyRel)):
                # skipping relations
                continue
            yield cast(DjangoField, fld)
returns iterator with all the fields that can be part of schema
ninja/orm/factory.py