[Answered ]-Catching integrity error in django generic view for ajax forms

You should return form_invalid in the except clause rather than using render_to_response

def form_valid(self, form):
    form.instance.user = self.request.user
    try:
        return super(DataCreate, self).form_valid(form)
    except IntegrityError:
        form.add_error('unique_name','You already have a user by that name')
        return self.form_invalid(form)