changelog does not retain object creation after it is deleted

[michaeldialpad]

NetBox version

v3.0.1

Python version

3.7

Steps to Reproduce

1. create new prefix object
2. validated CREATE changelog entry is present
3. delete newly created prefix object
4. validated DELETE changelog entry is present, but CREATE changelog entry is gone

Expected Behavior

I would expect changelog to keep previous change state if it is deleted

Observed Behavior

once object is deleted, changelog is gone

[jeremystretch]

Looks like this is a regression introduced in 88d2441 when adding the changelog reverse relationship for GraphQL. Django forces a CASCADE action on this relationship when the related object is deleted. We can probably just omit the reverse relationship from the model and make the forward query directly within the GraphQL object.

Thanks for the report!