python之如何将不是 "Document"的直接子类的子类存储在自己的集合中

根据 Document Inheritence 上的 MongoEngine 文档

我尝试创建一个基类，如下所示

import datetime 
from mongoengine import * 
connect("testdb") 
class Base(Document): 
   companyId = StringField(required=True) 
   creationDate = DateTimeField() 
   modifiedDate = DateTimeField() 
 
   meta = {'allow_inheritance': True} 
 
   def save(self, *args, **kwargs): 
       if not self.creationDate: 
           self.creationDate = datetime.datetime.now() 
       self.modifiedDate = datetime.datetime.now() 
       return super(Base, self).save(*args, **kwargs) 
 
 class Child1(Base): 
   #     identifier = StringField(required=True, unique=True, primary_key=True) 
    createdBy = StringField(required=True) 
 
 class Child2(Base):     
     memberId = StringField(required=True) 
 
 Child1(companyId='ab', createdBy='123').save() 
 Child2(companyId='ab', memberId='123').save() 

我的目标是在“testdb”下创建两个名为 Child1 和 Child2 的集合，但只创建一个名为“base”的集合，其中包含两个文档。

{ 
"_id" : ObjectId("5656b66381f49543f27af85a"), 
"_cls" : "Base.Child1", 
"companyId" : "ab", 
"creationDate" : ISODate("2015-11-26T13:06:01.689Z"), 
"modifiedDate" : ISODate("2015-11-26T13:06:01.689Z"), 
"createdBy" : "123" 
} 
 
/* 1 */ 
{ 
"_id" : ObjectId("5656b66381f49543f27af85b"), 
"_cls" : "Base.Child2", 
"companyId" : "ab", 
"creationDate" : ISODate("2015-11-26T13:06:03.621Z"), 
"modifiedDate" : ISODate("2015-11-26T13:06:03.621Z"), 
"memberId" : "123" 
} 

如何为我的子类指定不同的集合名称？

版本

python 2.7.10

mongodb 3.0.3

mongoengine 0.8.7

pymongo 2.7.2

请您参考如下方法:

这是根据 documentation 的预期行为你链接。

To create a specialised type of a Document you have defined, you may subclass it and add any extra fields or methods you may need. As this is new class is not a direct subclass of Document, it will not be stored in its own collection; it will use the same collection as its superclass uses.

据说要存储在它自己的集合中，您需要基类必须是抽象类，并且您可以选择使用其元属性指定子类集合的名称。

class Base(Document): 
   ... 
   meta = { 
       'allow_inheritance': True, 
       'abstract': True 
   } 
   ... 
 
class Child1(Base):     
    ... 
    meta = {'collection': 'child1'} # optional