orphaned polymorphic_ctype_id rows

[TZanke]

While debugging with django-polymorphic i deleted some data without django-polymorhpic. The real instances table rows are gone, but in the base polymorphic table, the rows with polymorphic_ctype_id still exist.

BaseClass.objects.all() => empty Queryset
BaseClass.objects.non_polymorphic().all() => Complete Queryset with all "old" data.

if polymorphic_ctype_id does not match any real row i would expect an exception.

Questions:

1.

how to delete the non_polymorphic-only BaseClass objects?
With non_polymorphic() i get existing BaseClasses plus "corrupt" BaseClasses. How to determine if a non_polymorphic object has no concrete object?

2.

how to avoid this corrupt state in the future? This should normally not happen, but i would feel better if i know the database never can enter this corrupt state.

[vdboor]

I've been in the same situation, and created a script for my specific use case:
https://github.com/django-fluent/django-fluent-pages/blob/master/fluent_pages/management/commands/remove_stale_pages.py

You could make this script even more generic.

I think it's hard to avoid this problem. When you remove a table, or perform a manual DELETE FROM in the database, there is no "cascade delete" to the base table so the base records will remain. Only using model.delete() will remove both the subclass and base class.