2

Preface

I need to have objects (Object model) with an individual set of fields (Field model). It contains name and type (see the diagram). Each connection between Object and Field stores the field's value. Datatype of value depends on the Field type property and physically the value will be stored in one of the predefined db columns (value_number, value_text, ...).

How I want it to work:

field = Field.objects.get(pk=1)
sought_for = Object.fields.filter(field=field, value='test')

Is there a way to create such a field that can be put to QuerySet just as simple as in the example but it actually, depending on the field's type, uses different db column or even columns as I suppose that in the future there will types that involve more than one column to store its value.

P.S. I tried some EAV applications but they seemed to be too complicated for my case.

The diagram:

  • Field model, it stores name and type of fields
  • FieldValue, the model the values for the fields are stored.

How I see the db realization

UPD: Eventually I came to a thought that the very approach to use Postgres (or any relational database) is not the best choice. I got this implemented easily in MongoDB.

Boris S
  • 301
  • 3
  • 10
  • Do you need to filter on or search those fields later? – okm Apr 06 '12 at 13:35
  • Yes, of course. Like in the example `Object.fields.filter(field=field, value='test')` – Boris S Apr 06 '12 at 13:56
  • have you checked solutions listed here: http://stackoverflow.com/questions/7933596/django-dynamic-model-fields might be relevant – fsw Dec 06 '13 at 08:57

0 Answers0