Question

These are my models:

class war(models.Model):
    title = models.CharField(max_length=20)

class option(models.Model):
    warval =models.ForeignKey(war)
    value = models.CharField(max_length=10)

class warform(ModelForm):
    class Meta:
        model = war

class option_form(ModelForm):
    class Meta:
        model = option
    exclude = ('warval')

And this is the view which handles creation of option:

def warhandler(request,war_id):
    f=modelformset_factory(option,form=option_form)
    wobj=get_object_or_404(war,pk=war_id)
    if request.method == 'POST':
        formset = f(request.POST,queryset=option.objects.filter(warval=wobj))
        if formset.is_valid():
            formset.save()
            return HttpResponse("Saved!check your model")   
        else:
            return render_to_response("formset.html",RequestContext(request,{"set":formset}))
    else:
        formset = f(queryset=option.objects.filter(warval=wobj))
        print(formset)
        return render_to_response("formset.html",RequestContext(request,{"set":formset,"war":wobj}))

So when I submit the form to this view,I get the following error:

Exception Type: IntegrityError
Exception Value: hit_option.warval_id may not be NULL

I know what this error is and why it is coming but how can I remove this error?

Answer 1

Make warval a non-required field with

class option(models.Model):
    warval =models.ForeignKey(war, null=True)
    value = models.CharField(max_length=10)

or define formset.warval before saving, make a default value…

edit:

read here and here for using subset of fields on a form and saving.