如何使用mongoengine“插入如果不存在其他更新”？

I'm working with mongoengine in Django,
this is my document defination:

我在Django中使用mongoengine，这是我的文档定义：

class Location(mongoengine.Document):  
    user_id = mongoengine.IntField(required=True)  
    point = mongoengine.GeoPointField(required=True)

I want to do this:
given a user_id and a point:
if there is no document that have this user_id, create one with the user_id and point and save it;
else update the document with user_id with point.
Can I do this in one statement with mongoengine?

我想这样做：给定一个user_id和一个点：如果没有这个user_id的文档，用user_id创建一个并指向并保存它;否则用user_id用point更新文档。我可以用mongoengine在一个声明中这样做吗？

3 个解决方案

#1

Note that get_or_create is now scheduled to be deprecated, because with no transaction support in MongoDB it cannot ensure atomicity.

请注意，get_or_create现在计划不推荐使用，因为MongoDB中没有事务支持，因此无法确保原子性。

The preferred way is update with upsert:

首选方法是使用upsert进行更新：

Location.objects(user_id=user_id).update_one(set__point=point, upsert=True)

More on upserts on the MongoDB documentation.

有关MongoDB文档的upsert的更多信息。

#2

this is what I came up with:

这就是我提出的：

location = Location.objects.get_or_create(user_id=user_id)[0]  
location.point = point  
location.save()

#3

There is a new way to do it since version 0.9 (explained here):

从版本0.9开始，有一种新的方法（在此解释）：

location = Location.objects(user_id=user_id).modify(upsert=True, new=True, set__point=point)

It returns the created or updated object.

它返回创建或更新的对象。

#1