如何从 Mongo ObjectID 中提取创建日期 [英] How do I extract the created date out of a Mongo ObjectID
问题描述
我正在使用 Mongo shell 来查询我的 Mongo 数据库.我想将 ObjectID 中包含的时间戳用作我的查询的一部分,也用作提取到输出中的列.我已经设置 Mongo 自己创建 ObjectID.
I'm using the Mongo shell to query my Mongo db. I want to use the timestamp contained in the ObjectID as part of my query and also as a column to extract into output. I have setup Mongo to create ObjectIDs on its own.
我的问题是我不知道如何使用 ObjectID 来提取其时间戳.
My problem is I can not find out how to work with the ObjectID to extract its timestamp.
以下是我正在尝试解决的问题.createdDate"字段是占位符;不确定正确的字段是什么:
Here are the queries I am trying to get working. The 'createdDate' field is a placeholder; not sure what the correct field is:
//Find everything created since 1/1/2011
db.myCollection.find({date: {$gt: new Date(2011,1,1)}});
//Find everything and return their createdDates
db.myCollection.find({},{createdDate:1});
推荐答案
getTimestamp()
你需要的功能就是这个,它已经包含在你的shell中了:
getTimestamp()
The function you need is this one, it's included for you already in the shell:
ObjectId.prototype.getTimestamp = function() {
return new Date(parseInt(this.toString().slice(0,8), 16)*1000);
}
参考文献
从文档中查看此部分:
References
Check out this section from the docs:
此单元测试也演示了相同的内容:
This unit test also demostrates the same:
> db.col.insert( { name: "Foo" } );
> var doc = db.col.findOne( { name: "Foo" } );
> var timestamp = doc._id.getTimestamp();
> print(timestamp);
Wed Sep 07 2011 18:37:37 GMT+1000 (AUS Eastern Standard Time)
> printjson(timestamp);
ISODate("2011-09-07T08:37:37Z")
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