Django model structure for org charts

Question

I need to build org charts for positions in a company (CTO answers to CEO, Developers answer to CTO, etc), and I need to create a friendly UI to reflect this. The UI part is not my concern right now, because if I build the backend right, the frontend will be easy.

So without using any fancy patterns (like graphs), what would be the best structure for a Position model (making my life easier when I fetch the org chart)?

So far I've thought of something like the following, but having a parent foreign key to itself won't help me much if I need to go 10 levels deep in the org chart.

class Position(models.Model):
    name = models.CharField(max_length=100)
    company = models.ForeignKey(Company)  # irrelevant
    level = models.PositiveSmallIntegerField()  # depth level (not sure if I need this since I have parent_position)
    parent_position = models.ForeignKey("self")

PS. Earlier in my question I wanted to avoid using graphs and such, simply because I have zero knowledge about them, and am on a tight schedule. Would learning and using graphs be a lot of help in this case?

Answer 1

You could use django-mptt package for the project. It would compose your HR part as a tree structure and query subtrees in one batch without traversing the tree. Something like this should get you started(nothing near production obviously):

from mptt.models import MPTTModel, TreeForeignKey, TreeManager

class Organization(MPTTModel):
    name = models.CharField(max_length=255, unique=True)
    members = models.ManyToManyField(User)
    parent = TreeForeignKey('self', related_name='children')
    objects = TreeManager()