Edit Question - KnowledgeHub

Title Body

I've been banging my head against the desk for a couple weeks on this problem, so I figure it may be time to seek some help. I'm trying to implement a database structure which has hierarchical data of parts for assemblies. My main problem lies with trying to assign one "subassembly" to another "assembly"/tree. Refering to the example trees below- I have no problem creating and working with assembly 1 and 2. But when I make assembly 3, I get multiple objects returned errors when I call up the subassemblies (which I understand base on the way I'm attempting). assembly 1: assembly 2: assembly 3: 1.1 2.1 2.1 - 1.1.1 - 2.1.1 - 2.1.1 1.2 2.2 1.2 - 1.2.1 - 2.2.1 - 1.2.1 Here is the model I've been trying: #models.py snippet class Part(models.Model): part_name = models.CharField(max_length=30, primary_key=True) description = models.TextField(max_length=500, blank=True, null=True) revision = models.CharField(max_length=10, blank=True, null=True) def __unicode__(self): return u'%s' % (self.part_name) class Assembly(MPTTModel): name = models.ForeignKey(Part) parent = models.ForeignKey('self', null=True, blank=True, related_name='children') def __unicode__(self): return u'%s' % (self.name) #views.py snippet def assembly_details(request, assembly_name): context_instance=RequestContext(request) assembly = Assembly.objects.get(name=assembly_name) descendants_list = assembly.get_descendants(include_self=False) return render_to_response('assembly_details.html', locals(), context_instance,) So basically I'm creating very basic trees and linking to the more detailed data through the Part FK. I need to be able to query any assembly and look at it's descendants- so although I can call assembly 3,

Tags (comma-separated) Cancel