CODEWITHSUNDEEP
djangodjango-modelsdjango-forms
user3628119
user3628119

Reputation: 357

Django changing modelchoice's queryset

Model:

class Event(models.Model):
    organizer = models.ForeignKey( Person )
    event_date = models.DateField()

I want to create a form for event_id = 1:

form_class = modelform_factory( Event, exclude = () )
instance = Event.objects.get( id = 1 )
event_form = form_class( instance = instance )

Now, I want to alter the organizer select field so that it only shows the existing person as the only option. So:

event_form.fields[ 'organizer' ].queryset = Person.objects.filter( id = instance.organizer_id )

My question is this: in the process of assigning a new queryset, I need to do a new query to the database. I feel that this is unnecessary as I already have the specific organizer that I want to assign to (instance.organizer). Is there a way to convert this organizer instance into a queryset thereby avoiding the need to do a new query?

It's not a big deal for one form, but I do want to make a formset out of the modelform which would mean n queries for n forms. Thanks.

Upvotes: 0

Views: 95

Answers (1)

anjaneyulubatta505
anjaneyulubatta505

Reputation: 11675

Try this below code

from django import forms

instance = Event.objects.select_related().get(id=1)
choices = [(instance.organizer.pk, str(instance.organizer))]
event_form.fields[ 'organizer' ] = forms.ChoiceField(choices=choices)

Upvotes: 2

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