Deleting child table does not delete rows in parent table when using multi-table inheritance

[Stephen Finucane]

If you have a child model that depends on a parent model via multi-table inheritance, then deleting the child will not delete rows in the parent model's table.

I am aware that we don't use database-level cascades (ticket:21961) but I expected this to be implemented by Django in Python, given the docs (​https://docs.djangoproject.com/en/4.2/topics/db/models/#multi-table-inheritance) say that the automatically-created OneToOneField on the child model will have on_delete=models.CASCADE.

place_ptr = models.OneToOneField(
    Place,
    on_delete=models.CASCADE,
    parent_link=True,
    primary_key=True,
)

I have a minimal reproducer which can be found at ​https://github.com/stephenfin/django-bug-34796. In summary though, you simply need to create a table using multi-table inheritance and then delete that table. While the child table will be deleted, the corresponding rows in the parent table will remain.