MongoEngine GenericReferenceField高級查詢

Question

概述：

我的用戶文檔引用帶有FileFields的Image文檔。您無法使用FileField深入複製對象（爲什麼不？）。因此，對用戶文檔進行深度複製將關聯圖像（使用FileField）取消引用失敗。

---

我想查詢使用MongoEngine（0.7.8）的集合，如果我查詢這樣：

>>> cls.objects(Q(author=devin_user)) 
    [<FollowUserEvent: [<User: Devin> => <User: Strike>]>] 
    # Querying author works fine 

    >>> cls.objects(Q(parent=strike_user)) 
    [<FollowUserEvent: [<User: Devin> => <User: Strike>]>] 
    # Querying parent works fine 

    >>> cls.objects(Q(parent=strike_user) & Q(author=devin_user)) 
    *** TypeError: 'Collection' object is not callable. If you meant to call the '__deepcopy__' method on a 'Collection' object it is failing because no such method exists. 
    # Definitely fails here, but why? 


    # Even stranger, if I combine a query on parent and hidden_at it succeeds, but if I combine a query on author and hidden_at it gloriously fails 
    >>> cls.objects(Q(parent=strike_user) & Q(hidden_at=None)) 
    [<FollowUserEvent: [<User: Devin> => <User: Strike>]>] 
    # Querying parent works fine 

    >>> cls.objects(Q(author=devin_user) & Q(hidden_at=None)) 
    *** TypeError: 'Collection' object is not callable. If you meant to call the '__deepcopy__' method on a 'Collection' object it is failing because no such method exists. 
    # Boom! 

strike_user和devin_user兩種用戶的文檔。這是事件的樣子（順便說一下，它允許繼承）。

class Event(Document):            
     """                
     :param anti: tells if an event is related to an inverse event 
      e.g. follow/unfollow, favorite/unfavorite     
     :param partner: relates an anti-event to an event.    
      only set on the undoing event        
     """                
     author = GenericReferenceField(required=True)     
     parent = GenericReferenceField(required=True)     
     created_at = DateTimeField(required=True, default=datetime.now) 
     hidden_at = DateTimeField()          

     anti = BooleanField(default=False)        
     partner = ReferenceField('Event', dbref=False)     
     meta = {              
      'cascade': False,           
      'allow_inheritance': True } 

     def __repr__(self): 
      action = "=/>" if self.anti else "=>" 
      return "<%s: [%s %s %s]>" % (self.__class__.__name__, 
       self.author.__repr__(), action, self.parent.__repr__()) 

好像對我的錯誤，但我聽到的反饋:)

---

更新很感興趣：

似乎mongoengine/queryset.py：98個來電覆制.deepcopy。這跟在一個ReferenceField之後，並且試圖複製它的FileField數據。不幸的是，這不起作用。

Class Image(Document): 
     file = FileField(required=True) 

    Class User(Document): 
     name = StringField() 
     image = ReferenceField('Image') 

    >>> copy.deepcopy(user) 
    *** TypeError: 'Collection' object is not callable. If ... 

    >>> user.image = None 
    >>> copy.deepcopy(user) 
    <User: Devin> 

Answer 1

原來，這是一個錯誤！我在概述中所說的是正確的。錯誤

有用的鏈接[狀態：

status of the bug

mailing list discussion