Django級聯保存？

Question

我有我的用戶登記表上的一個方法，看起來像這樣：

def save(self): 
    user = User(
     username = self.cleaned_data['username'], 
     email = self.cleaned_data['email1'], 
     first_name = self.cleaned_data['first_name'], 
     last_name = self.cleaned_data['last_name'], 
    ) 
    user.set_password(self.cleaned_data['password1']) 
    user.profile = Profile(
     primary_phone = self.cleaned_data['phone'], 
    ) 
    user.profile.address = Address(
     country = self.cleaned_data['country'], 
     province = self.cleaned_data['province'], 
     city = self.cleaned_data['city'], 
     postal_code = self.cleaned_data['postal_code'], 
     street1 = self.cleaned_data['street1'], 
     street2 = self.cleaned_data['street2'], 
     street3 = self.cleaned_data['street3'], 
    ) 
    user.save() 
    return user 

問題是，當我打電話form.save()它創建如預期user對象，但不保存他的個人資料或地址。爲什麼它不會級聯並保存所有的子模型？我懷疑我可以手動調用user.profile.save()和user.profile.address.save()，但我想整個事情成功或失敗在一起。什麼是最好的方法來做到這一點？

---

目前的解決方案：

def save(self): 
    address = Address(
     country = self.cleaned_data['country'], 
     province = self.cleaned_data['province'], 
     city = self.cleaned_data['city'], 
     postal_code = self.cleaned_data['postal_code'], 
     street1 = self.cleaned_data['street1'], 
     street2 = self.cleaned_data['street2'], 
     street3 = self.cleaned_data['street3'], 
    ) 
    address.save() 

    user = User(
     username = self.cleaned_data['username'], 
     email = self.cleaned_data['email1'], 
     first_name = self.cleaned_data['first_name'], 
     last_name = self.cleaned_data['last_name'], 
    ) 
    user.set_password(self.cleaned_data['password1']) 
    user.save() 

    profile = Profile(
     primary_phone = self.cleaned_data['phone'], 
    ) 
    profile.address = address 
    profile.user = user 
    profile.save() 

我不得不做出profile 「中央」 的對象。需要設置profile.user = user，而不是user.profile = profile，使其工作（我猜是因爲關鍵是在剖面模型，而不是在用戶模型）。

---

較新的解決方案：

我參加了一個暗示從this article在this answer建議。

現在我已經分開我的模型形式和移動的邏輯到視圖：

def register(request): 
    if request.POST: 
     account_type_form = forms.AccountTypeForm(request.POST) 
     user_form = forms.UserForm(request.POST) 
     profile_form = forms.ProfileForm(request.POST) 
     address_form = forms.AddressForm(request.POST) 

     if user_form.is_valid() and profile_form.is_valid() and address_form.is_valid(): 
      user = user_form.save() 
      address = address_form.save() 
      profile = profile_form.save(commit=False) 
      profile.user = user 
      profile.address = address 
      profile.save() 
      return HttpResponseRedirect('/thanks/') 
    else: 
     account_type_form = forms.AccountTypeForm() 
     user_form = forms.UserForm() 
     profile_form = forms.ProfileForm() 
     address_form = forms.AddressForm() 

    return render_to_response(
     'register.html', 
     {'account_type_form': account_type_form, 'user_form': user_form, 'address_form': address_form, 'profile_form': profile_form}, 
     context_instance=RequestContext(request) 
    ) 

我不是太喜歡快慰的觀點，但我想我得到一個更靈活一點這辦法？

Answer 1

它不會級聯保存，因爲它實際上並不知道是否需要保存其他對象需要。

要做到這一點一氣呵成，第一start a transaction：

@transaction.commit_on_success 
def save(self): 
    .... 

然後保存子對象依次是：

user.profile.address.save() 
    user.profile.save() 
    user.save() 

Answer 2

的問題是，你想創建或在更新領域尚未存在的用戶對象。所以其他字段並不真正更新，因爲它們沒有關聯到子字段的任何主鍵。

你實例化一個新的模式場每一次，你必須確保你節省使得兒童模型場有一個id（主鍵）與關聯。

你需要更多的東西是這樣的：

def save(self): 
    user = User(
     username = self.cleaned_data['username'], 
     email = self.cleaned_data['email1'], 
     first_name = self.cleaned_data['first_name'], 
     last_name = self.cleaned_data['last_name'], 
    ) 
    ## save user so we get an id 
    user.save() 

    ## make sure we have a user.id 
    if user.id: 
     ## this doesn't save the password, just updates the working instance 
     user.set_password(self.cleaned_data['password1']) 
     user.profile = Profile(
      primary_phone = self.cleaned_data['phone'], 
     ) 
     ## save the profile so we get an id 
     user.profile.save() 

    ## make sure we have a profile.id 
    if user.profile.id: 
     user.profile.address = Address(
      country = self.cleaned_data['country'], 
      province = self.cleaned_data['province'], 
      city = self.cleaned_data['city'], 
      postal_code = self.cleaned_data['postal_code'], 
      street1 = self.cleaned_data['street1'], 
      street2 = self.cleaned_data['street2'], 
      street3 = self.cleaned_data['street3'], 
     ) 
     ## save the profile address 
     user.profile.address.save() 

    ## final save to commit password and profile changes 
    user.save() 
    return user 

這你怎麼回事級聯save()事情只是感覺不對。你容易途中有太多的錯誤，如果任何字段不保存，你會最終有一個完整的部分用戶實例和posisbly與副本最終用戶是否回去，然後再試一次。不好玩！

編輯：刪除了後半部分，因爲它不準確。