Question

I’m new to Python/Django and i have a question.
I need to get a QuerySet filtered by a Value from a multidimensional dictionary (JSONField).
So far, I got this:

def make_cond(name, value):
    from django.utils import simplejson
    cond = simplejson.dumps({key:value})[1:-1] # remove '{' and '}'
    return ' ' + cond # avoid '"'

Post.objects.filter(JSONField__contains=make_cond('key', 'value')) 

That works, but only for the 1st dimension of the dict.
How can I reach the other dimensions?

Answer 1

SQL can’t help you with that.

Given an arbitrary json object whose serialization might look like this,

'{"a": {"c": "C", "b": "B"}, "c": {}, "b": {"e": "E", "d": "D"}}'

you’d have to construct a LIKE clause that matches, say, the {"a", then another { and then "b": "B" without caring what’s in place of "c": "C". A LIKE clause supports wildcards only before and after, so you can’t get what you want.

It’s possible you could figure it out with a fulltext index; you could try Haystack or Sphinx for that.

The correct tool for the job, though, is a NoSQL database like mongodb.