Question

I need to be able to make a tree like structure in the appengine database.
I have try to make an object reference itself but have not gotten it to work.

class Item(db.Model):
    children = db.ListProperty(db.ReferenceProperty(Item))

Answer 1

Alternatively, you can store references to children in the parent with:

class Node(db.Model):
    children = db.ListProperty(db.Key)

This answer shamelessly stolen (with credit!) from Nick Johnson’s answer to this related question