Django self-recursive foreignkey filter query for all childs

sunn0's suggestion is great idea, but get_all_children() returns weird results. It returns something like [Person1, [Person3, Person4], []]. It should be changed to like below.

def get_all_children(self, include_self=True):
    r = []
    if include_self:
        r.append(self)
    for c in Person.objects.filter(parent=self):
        _r = c.get_all_children(include_self=True)
        if 0 < len(_r):
            r.extend(_r)
    return r

You should read about Modified preorder tree traversal. Here is django implementation. https://github.com/django-mptt/django-mptt/

If you know the max depth of your tree, you could try something like this (untested):

Person.objects.filter(Q(parent=my_person)|Q(parent__parent=my_person)| Q(parent__parent__parent=my_person))

You can always add a recursive function to your model:

EDIT: Corrected according to SeomGi Han

def get_all_children(self, include_self=True):
    r = []
    if include_self:
        r.append(self)
    for c in Person.objects.filter(parent=self):
        _r = c.get_all_children(include_self=True)
        if 0 < len(_r):
            r.extend(_r)
    return r

(Don't use this if you have a lot of recursion or data ...)

Still recommending mptt as suggested by errx.

EDIT: 2021 since this answer is still getting attention :/

Use django-tree-queries instead!