I need to store a tree data structure in my database, for which I plan on using django-treebeard or possibly django-mptt. My source of confusion is that each node could be one of three different possible types: root nodes will always be a type A entity, leaf nodes a type C entity, and anything in between will be a type B entity. I woul...
Hi! I'm trying to make a model for categorizing some objects. I already tried using django-mptt to easily retrieve related categories, and now I'm searching different solutions to find the best one. I can't find out though what are main differences between Materialized Path, Adjacency List and Nested Set. Wikipedia didn't give me a sh...
I'm looking for a Django tree library and doing my best to avoid Nested Sets (they're a nightmare to maintain). The cons of the adjacency list model have always been an inability to fetch descendants without resorting to multiple queries. The WITH clause in Postgres seems like a solid solution to this problem. Has anyone seen any perfo...
I'm getting a non-descriptive (or at least I don't know how to interpret in this context) error message when sub-lassing from a Django-Treebeard node and am not sure how to debug. I'm using the installation instructions at: http://code.tabo.pe/django-treebeard/src/tip/tbexample/ (see at end of posting). I create a subclass of MP_Node a...
I've setup Treebeard in Django and everything seems to have gone well. I tried to setup the admin system and I can see my models being presented in the admin interface. However, when I try to add new data using the admin interface, I get the following error in my template. The code still works fine, and I did a check in my DB and the da...