Python-сообщество

#models.py
class Test(Model):
    filed1 = ...
    field2 = ...
    ...

    class Meta:
        unique_together = ('field1', 'field2')

#forms.py
class TestForm(ModelForm):
    class Meta:
        model = Test
        exclude = ('field2')

class TestForm(ModelForm):
    curr_field1 = ...

    class Meta:
        model = Test

    def __init__(self, test, *args, **kwargs):
        super(ModelForm, self).__init__(*args, **kwargs)
        self.curr_field1 = test.field1
        self.field2 = test.field2

    def clean_field1(self):
        field1 = self.cleaned_data['field1']
        field2 = self['field2'].data
        if Test.objects.filter(field1 = field1, field2 = field2):
            if field1 <> self.curr_field1:   
                raise ValidationError(u'field1 and field2 isn't unique!')