mongodb - 如果不存在则创建文档，否则推送到数组 [英] mongodb - create doc if not exist, else push to array

问题描述

我有一个格式如下的文档:

I have a document in the following form:

{
"_id" : ObjectId("4d2d8deff4e6c1d71fc29a07"),
"user_id" : "714638ba-2e08-2168-2b99-00002f3d43c0",
"events" : [
        {
                "profile" : 10,
                "data" : "....."
        }
        {
                "profile" : 10,
                "data" : "....."
        }
        {
                "profile" : 20,
                "data" : "....."
        }
        ...
   ]
 }

我想要某种upsert 语句.它需要添加一个 event 到 user_id 的 events 数组，以防已经存在这样的文档，否则它需要使用event 项目.

I'd like to have some sort of upsert statement. It needs to add an event to the events array for user_id in case there is already such doc exist, else it needs to create the doc with the event item.

能做到吗?

推荐答案

您可以在 Mongo 中进行 upserts，请参阅 Mongo 文档:

You can do upserts in Mongo, see "Upserts with Modifiers" from the Mongo doc:

您可以使用带有修饰符的 upsert手术.在这种情况下，修饰符将应用于更新标准成员和结果对象将被插入.

You may use upsert with a modifier operation. In such a case, the modifiers will be applied to the update criteria member and the resulting object will be inserted.

您需要的查询将如下所示:

The query you need will look like:

db.events.update( { "user_id" : "714638ba-2e08-2168-2b99-00002f3d43c0" }, 
{ $push : { "events" : { "profile" : 10, "data" : "X"}}}, {"upsert" : true});

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