Disallow the use of double underscores in a custom field name

[JonasEinfach]

NetBox version

v3.5.0

Python version

3.8

Steps to Reproduce

1. Create Custom Field --> Type: Object (Location), Assigned Models: ipam | VLAN
2. Go to IPAM --> Vlans --> Edit Vlan and chose Location Object by custom Field
3. In the Vlans overview chosed location not showing, if you click on the specific vlan the location is showing
4. Same behavior if you assign the custom field to other models like ipam | ip addresses

Expected Behavior

Location from custom Field should be shown in vlan overview

Observed Behavior

Location from custom Field no shown in vlan overview

Location from custom Field only show if you click on the vlan

[kkthxbye-code]

Cannot replicate this, it seems likely that you added the wrong column to the table. Please revise your replication steps.

My test:

[JonasEinfach]

I create another custom Field with another Name and it works.

If I delete the Custom Field Test__Location and recreate the Field with the same Name, I have the same Issue.
Maybe the Name Test__Location trigger anything. Very Strange behaviour.

I would close the bug. Thank you for your time.

[jeremystretch]

I notice that you're using two underscores in the custom field name. This is likely the issue: The table is interpreting the double underscore as a relationship (i.e. test.location) rather than a single field name. Try using a single underscore.

[JonasEinfach]

Perfect, thank you!

[jeremystretch]

We should probably prevent the use of double underscores in a custom field name to prevent this issue.