Recursive delete in google app engine

Question

I\'m using google app engine with django 1.0.2 (and the django-helper) and wonder how people go about doing recursive delete. Suppose you have a model that\'s something like thi

Answer 1

You need to implement this manually, by looking up affected records and deleting them at the same time as you delete the parent record. You can simplify this, if you wish, by overriding the .delete() method on your parent class to automatically delete all related records.

For performance reasons, you almost certainly want to use key-only queries (allowing you to get the keys of entities to be deleted without having to fetch and decode the actual entities), and batch deletes. For example:

db.delete(Bottom.all(keys_only=True).filter("daddy =", top).fetch(1000))