django-eav provides an Entity-Attribute-Value storage model for django apps.
For a decent explanation of what an Entity-Attribute-Value storage model is, check Wikipedia.
This software was inspired / derived from the excellent eav-django written by Andrey Mikhaylenko.
There are a few notable differences between this implementation and the eav-django implementation.
- This one is called django-eav, whereas the other is called eav-django.
- This app allows you to to 'attach' EAV attributes to any existing django model (even from third-party apps) without making any changes to the those models' code.
- This app has slightly more robust (but still not perfect) filtering.
You can install django-eav directly from guthub:
pip install -e git+git://github.com/mvpdev/django-eav.git#egg=django-eav
Add eav to your INSTALLED_APPS in your project's settings.py file.
Register your model(s)
Before you can attach eav attributes to your model, you must register your model with eav:
>>> import eav >>> eav.register(MyModel)
Generally you would do this in your models.py immediate after your model declarations.
Create some attributes
>>> from eav.models import Attribute >>> Attribute.objects.create(name='Weight', datatype=Attribute.TYPE_FLOAT) >>> Attribute.objects.create(name='Color', datatype=Attribute.TYPE_TEXT)
Assign eav values
>>> m = MyModel() >>> m.eav.weight = 15.4 >>> m.eav.color = 'blue' >>> m.save() >>> m = MyModel.objects.get(pk=m.pk) >>> m.eav.weight 15.4 >>> m.eav.color blue >>> p = MyModel.objects.create(eav__weight = 12, eav__color='red')
Filter on eav values
>>> MyModel.objects.filter(eav__weight=15.4) >>> MyModel.objects.exclude(name='bob', eav__weight=15.4, eav__color='red')