Django transaction.atomic() 不起作用

Question

我对这段代码有一个问题：

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)

即使phone_formset或email_formset无效并且视图渲染表单时出现错误，transaction.atomic()也会保存对象“o”（不应保存对象）

Answer 1

它不起作用，因为原子事务仅在引发异常时才会回滚。在您的情况下，您只返回正常的响应对象，这不会触发回滚并因此提交到数据库。

有关django 文档中原子事务的更多信息。

将您的代码更改为如下所示（未确认它是否有效，但此类示例位于链接的文档中）：

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)