How to revert changes, specifically deletions, with django-simple-history

Question

We have django-simple-history set up for our models. Recently a whole bunch of models were mysteriously deleted. This was noticed a few days after the fact, so it would be nice to avoid a full DB backup restore since that would wipe manual changes that happened after the fact.

I cannot find any way to easily restore an model instance, specifically a deleted one. I can query the Historical version of the model and find everything that was deleted. With that I can also observe that all of them had deletions as their last change. I can use the instance property on history - 1 to get the state before deletion but if I try to save that it errors since the model instance was deleted and doesn't exist anymore.

So basically, what is the cleanest way to restore a deleted model instance if I have the Historical record of it with django-simple-history? I would like to retain the history if possible, so I am looking into any solution before totally recreating the objects.

Answer 1

As I understand, the question, it is about restoring a deleted model instance, not the class itself. So Kal's answer does not help here. To restore a deleted instance, simple history can NOT be used. According to the documentation, simple history can only restore model instances that are still existing. Since you have a full backup of the database, you can import this database into the django environment, load the old model instance from this backup database and save it to the production database (choose the database in django shell with "using"). See this post. The best way to avoid such situations is to use the app "reversion". With this django-app, you actually can restore deleted instances. See the documentation.