Django transaction.atomic() 不起作用

Question

I have a problem with this code:

PhoneNumberFormSet = inlineformset_factory(Person, PhoneNumber, fields=('phone_number',), 
can_delete=False, extra=1)

EmailAddressFormSet = inlineformset_factory(Person, EmailAddress, fields=('email_address',), 
can_delete=False, extra=1)

class PersonCreateView(CreateView):

    form_class = PersonForm
    success_url = reverse_lazy('person-list')
    template_name = 'contacts/person_create.html'

    def get_context_data(self, **kwargs):
        data = super(PersonCreateView, self).get_context_data(**kwargs)
        data['phone_formset'] = PhoneNumberFormSet(self.request.POST or None)
        data['email_formset'] = EmailAddressFormSet(self.request.POST or None)
        return data

    def form_valid(self, form):
        context = self.get_context_data()
        phone_formset = context['phone_formset']
        email_formset = context['email_formset']
        with transaction.atomic():
            o = form.save() # <--- this object is saved even when formsets below are not valid
            condition = phone_formset.is_valid() and email_formset.is_valid()
            if not condition:
                return render(self.request, self.template_name, self.get_context_data())
            phone_formset.instance = o
            phone_formset.save()
            email_formset.instance = o
            email_formset.save()
        return super(PersonCreateView, self).form_valid(form)

The transaction.atomic() is saving obcject "o" even when phone_formset or email_formset are not valid and view renders forms with errors (object should not be saved)

Answer 1

It doesn't work because atomic transactions roll back only if exception is raised. In your case, you just return normal response object, which doesn't trigger roll back and hence commits to database.

More about atomic transactions in django docs .

Change your code to something like this (didn't confirm it's working, but this type of example is in the linked docs):

from django.core.exceptions import ValidationError

def form_valid(self, form):
        context = self.get_context_data()
        phone_formset = context['phone_formset']
        email_formset = context['email_formset']
        try:
            with transaction.atomic():
                o = form.save() # <--- this object is saved even when formsets below are not valid
                condition = phone_formset.is_valid() and email_formset.is_valid()
                if not condition:
                    raise ValidationError
                phone_formset.instance = o
                phone_formset.save()
                email_formset.instance = o
                email_formset.save()
        except ValidationError:
            return render(self.request, self.template_name, self.get_context_data())
        return super(PersonCreateView, self).form_valid(form)