ValueError：「需要在此多對多關係可以使用之前爲字段」id「設置一個值」

我已經在我的註冊頁面上創建了一個擴展用戶模型。這兩個定製模型是「克里斯汀」和一個名爲「Rolle」的多對多字段（該組織的角色）。ValueError：「需要在此多對多關係可以使用之前爲字段」id「設置一個值」

後我加入了很多對多場，我收到以下錯誤信息：ValueError異常在/帳號/註冊/ - 「Userextended：username_that_I_registered_with」需要有場「ID」的值，在此之前可以使用多對多的關係。

我已經搜索了三個小時了，看起來解決方法是在保存模型之前在用戶ID上使用commit = False。但是，我對Django和Python很陌生，並且無法準確指出我應該在哪裏編寫代碼，而且我的嘗試迄今未成功。如果您可以幫助我解決這個問題，請通過代碼提供解決方案。

我models.py文件：

class User(auth.models.User,auth.models.PermissionsMixin): 
def __str__(self): 
    return "@{}".format(self.username) 

class Personrolle(models.Model): 
    id = models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID') 
    persrolle = models.CharField(max_length = 30, verbose_name="Role") 
    def __str__(self): 
     return self.persrolle 

class Userextended(models.Model): 
    id = models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID') 
    user = models.OneToOneField(User, on_delete=models.CASCADE) 
    cristin = models.IntegerField(blank=True, null=True) 
    rolle = models.ManyToManyField(Personrolle) 

    def __str__(self): 
     return self.user.username 

...

我forms.py文件：

... 

from django import forms 
from django.contrib.auth.models import User 
from accounts.models import Userextended 
from accounts.models import Personrolle 
from django.contrib.auth.forms import UserCreationForm 
class UserCreateForm(UserCreationForm): 

    cristin = forms.IntegerField(required=False) 
    rolle = forms.ModelChoiceField(queryset=Personrolle.objects.all()) 

    class Meta(): 
     fields = ('first_name','last_name','username','email','password1','password2') 
     model = User 
     labels = {'username': 'Email', 
        'first_name': 'First name', 
        'last_name': 'Last name', 
        'email': 'Confirm email', 
        'password1': 'Password', 
        'password2': 'Confirm password', 
        'cristin': 'Cristin-ID', 
        'rolle': 'Rolle'} 

    def save(self, commit=True): 
     if not commit: 
      raise NotImplementedError("Can't create User and Userextended without database save") 
     user = super(UserCreateForm, self).save(commit=True) 
     user_profile = Userextended(user=user,cristin=self.cleaned_data['cristin'],rolle=self.cleaned_data['rolle']) 
     user_profile.save() 
     return user 

...

錯誤的更詳細描述

請求方法：POST
請求URL：http://127.0.0.1:8000/accounts/signup/
Django的版本：1.11.2
異常類型：ValueError異常
異常值：「Userextended：username_that_I_registered_with」之前需要有現場「ID」的值這種多對多的關係可以被使用。
異常位置：... /蟒蛇/ ENVS/myEnv/lib中/ python3.6 /站點包/ Django的/ DB /模型/場/在初始化 related_descriptors.py，線830
Python的可執行文件：... /蟒蛇/ ENVS/myEnv /斌/ Python的
Python版本：3.6.1

我回溯：

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner 
    41.    response = get_response(request) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response 
    187.     response = self.process_exception_by_middleware(e, request) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response 
    185.     response = wrapped_callback(request, *callback_args, **callback_kwargs) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/views/generic/base.py" in view 
    68.    return self.dispatch(request, *args, **kwargs) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/views/generic/base.py" in dispatch 
    88.   return handler(request, *args, **kwargs) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/views/generic/edit.py" in post 
    217.   return super(BaseCreateView, self).post(request, *args, **kwargs) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/views/generic/edit.py" in post 
    183.    return self.form_valid(form) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/views/generic/edit.py" in form_valid 
    162.   self.object = form.save() 

File "…PROJECT/accounts/forms.py" in save 
    57.   user_profile = Userextended(user=user,cristin=self.cleaned_data['cristin'],rolle=self.cleaned_data['rolle']) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/db/models/base.py" in __init__ 
    566.        _setattr(self, prop, kwargs[prop]) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py" in __set__ 
    536.   manager = self.__get__(instance) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py" in __get__ 
    513.   return self.related_manager_cls(instance) 

File ".../anaconda/envs/myEnv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py" in __init__ 
    830.         (instance, self.pk_field_names[self.source_field_name])) 

Exception Type: ValueError at /accounts/signup/ 
Exception Value: "<Userextended: [email protected]>" needs to have a value for field "id" before this many-to-many relationship can be used.

來源

2017-06-28 Christian

發生錯誤信息是因爲「rolle」應該指定爲多對一關係而不是多對多關係。該型號已更新至以下版本，現在可以完美工作：

class Userextended(models.Model): 
    ... 
    rolle = models.ForeignKey(Personrolle, models.SET_NULL, blank=True, null=True)

來源

2017-06-28 14:43:03 Christian

你只需要編輯您的保存方法在你的形式，

def save(self, commit=True): 
    if not commit: 
     raise NotImplementedError("Can't create User and Userextended without database save") 
    user = super(UserCreateForm, self).save(commit=True) 
    user_profile = Userextended(user=user,cristin=self.cleaned_data['cristin']) 
    user_profile.save() 
    user_profile.rolle.add(self.cleaned_data['rolle']) 
    user_profile.save() 
    return user

您需要先保存UserExtended模式，那麼Rolle實例添加到多對多的關係。

來源

2017-06-28 14:33:20 zaidfazil

ValueError：「需要在此多對多關係可以使用之前爲字段」id「設置一個值」

回答

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