__empty=False filter not working / filter on cabled front ports in Export Templates

[ajsiersema]

I'm trying to filter cabled / non cabled Device Front Ports in an Export Template.

This works for front ports without a cable:

{% for server in queryset %}
{%- for port in server.frontports.filter(cable_id=None)  -%}

Filtering ports with a cable, this seems to work, but leaves me with a nagging feeling that I really should be testing for not None (but how ?):

{%- for port in server.frontports.filter(cable_id__gt=-1)  -%}

I tried this instead, but I'm getting this error: Unsupported lookup 'empty' for ForeignKey or join on the field not permitted. :

{%- for port in server.frontports.filter(cable_id__empty=False)  -%}

Does anyone know if using gt=-1 is the only solution, or if there's a better alternative ?

As an aside, cabled only seems to work in GraphQL:

device_list(name:"foo") {
  frontports(cabled: true)

[candlerb]

https://docs.djangoproject.com/en/4.2/ref/models/querysets/#field-lookups
https://docs.djangoproject.com/en/4.2/ref/models/querysets/#isnull

Looks like cable_id__isnull=False is likely to be the answer.

[ajsiersema]

Indeed.
Thanks for adding the links, very useful for any future query questions that might pop up, that are not covered by the Netbox documentation.

[candlerb]

Cheers. It's not always obvious, but the query parameters in REST API and GraphQL APIs (defined as "filtersets" in the code) are not the same as the filter expressions in the Django ORM, even though some terms are similar.