Django的模型多ForeignKey的一個表

Question

Possible Duplicate:
Django: Why some fields clashes with other

我試着描述模型，但Django的報告一些錯誤。我可以修復一些錯誤，但無法修復所有錯誤。然後我不會改變它來更清楚地描述我的目的：

from django.db import models 

class Person(models.Model): 
    name = models.CharField(max_length=128) 
    father_is = models.ForeignKey('self') 

    def __unicode__(self): 
     return self.name 

class Group(models.Model): 
    name = models.CharField(max_length=128) 
    members = models.ManyToManyField(Person, through='Membership') 
    led_by = models.ForeignKey(Person) 

    def __unicode__(self): 
     return self.name 

class Membership(models.Model): 
    person = models.ForeignKey(Person) 
    group = models.ForeignKey(Group) 
    date_joined = models.DateField() 
    invite_reason = models.CharField(max_length=64) 
    invited_by = models.ForeignKey(Person) # who invited this person to this group 

你能否給我一個解決方案，請問？ （這是2個字段的錯誤：led_by和invited_by） 非常感謝！ PS：我剛開始學習Django。

編輯：現在我知道這是關於Django的ORM的限制。 OFFTOPIC！

Answer 1

是在單個模型上有多個外鍵屬於同一類型的問題？在這種情況下，django無法爲您設置自動向後關係，因此您需要明確指定related_name。有關說明

見 the docs

編輯：從你的錯誤 ，似乎正是這個問題。它甚至會告訴你該怎麼做：

Add a related_name argument to the definition for 'members'

EDIT2： 好了，現在我們取得了一些進展。儘管如此，答案仍然是「閱讀文檔」。從docs on using through relations（強調）：

There are a few restrictions on the intermediate model:

• Your intermediate model must contain one - and only one - foreign key to the target model (this would be Person in our example). If you have more than one foreign key, a validation error will be raised.

• Your intermediate model must contain one - and only one - foreign key to the source model (this would be Group in our example). If you have more than one foreign key, a validation error will be raised.