Listing only usable values in OneToOneField Django

Question

I want to list only usable items in OneToOneField not all items, its not like filtering values in ChoiceField because we need to find out only values which can be used which

Answer 1

You need something like this in the init() method of your form.

def __init__(self, *args, **kwargs):

    super(BarForm, self).__init__(*args, **kwargs)

    # returns Bar(s) who are not in Foo(s).
    self.fields['foo'].queryset = Bar.objects.exclude(id__in=Foo.objects.all().values_list(
            'bar_id', flat=True))

PS: Code not tested.