Schema is loading deferred properties

[vitalik]

Discussed in https://github.com/vitalik/django-ninja/discussions/928

^{Originally posted by mustafa0x November 17, 2023}

class File(Schema):
    id: int
    text: str | None = None

@router.get('/file/{file_id}/', response=File, exclude_unset=True)
def get_file(request: ASGIRequest, file_id: int):
    return File.objects.only(('id',)).get(id=file_id)

The response includes the text, even though I excluded/deferred it using only.

[mustafa0x]

Sorry @vitalik, it seems like things are indeed working properly. This can be closed!

[mustafa0x]

Ok, I apologize again, things are indeed not working as originally reported.

The following line is what triggers instance.refresh_from_db(fields=[field_name]) in django.

https://github.com/vitalik/django-ninja/blob/6f27eeef965f15091b7f51a2a9f4d5eef275f674/ninja/schema.py#L65

[mustafa0x]

Something like this should be a good solution. It might need to be made opt-in, to avoid a breaking change.

if key in self._obj.get_deferred_fields():
    # skip field

[mustafa0x]

Similar discussion: https://github.com/pydantic/pydantic/discussions/6861

[mustafa0x]

https://github.com/pydantic/pydantic/issues/8192

Lazy loaded orm fields are loaded inadvertently by model_validate. I'd like to be able to exclude fields from model_validate.

[mustafa0x]

This overlaps with #333.

Also, I filed an issue in pydantic core https://github.com/pydantic/pydantic-core/issues/1095