MongoEngine GenericReferenceField高级查询

Question

概述：

我的用户文档使用FileFields引用图像文档。不能用FileField深入复制对象(为什么？)深入复制用户文档，取消关联的映像(使用FileField)，因此失败。

我试图使用MongoEngine (0.7.8)查询一个集合，如果我是这样查询的话：

    >>> 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是两个用户文档。下面是事件的外观(顺便说一句，它确实允许继承)。

    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__())

对我来说好像是个窃听器，但我很想听到反馈:)

更新：

看起来mongoengine/queryset.py:98调用copy.deepcopy。它遵循一个ReferenceField，并试图复制它的FileField数据。不幸的是，这不起作用。

    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

原来，这是个虫子！我在概述中所说的是正确的。[臭虫的状态

有用的链接：

bug的状态

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