Order items that have an external parent_id ?

[danielsum]

Hi there,

Is it possible to order items that are scoped by an external parent_id ?

Exemple I have this :

articles

• id

photos

• article_id
• parent_id
• lft
• rgt
• depth

=> What I want is the ability to order photos of a specified article_id without having a root photos (no children all siblings).

=> is it possible ? And how to achieve that ?