如何从 Spring Data MongoDB 中的 MongoDB ObjectId 中提取时间戳? [英] How do you extract a timestamp from a MongoDB ObjectId in Spring Data MongoDB?

问题描述

MongoDB documentation 建议从 ObjectId 中提取插入时间，而不是使用单独的时间字段.有谁知道如何使用 Spring Data MongoDB 做到这一点?

特别是，我想查询插入特定日期范围的文档.

解决方案

从 ObjectId 中获取时间很容易...但是您无法获得毫秒精度.

org.bson.types.ObjectId 有 2 种方法可供您使用:getTimeSecond() 和 getTime()(与`getTimeSecond() * 1000L).这些将获得您的 unix 时间戳.

我没有将 MongoDB 与 Spring 一起使用 - 但如果你能掌握实际的 ObjectId 实例，它就像调用上述方法之一一样简单.

现在 - 要查询某个时间范围内的文档，您必须倒退并根据时间戳创建 ObjectId 对象.再一次 - 这很简单 - ObjectId 有一个构造函数可以为您执行此操作:

ObjectId(日期时间)

所以 - 创建 2 个 ObjectId 实例来代表您的最小和最大时间界限，然后执行如下查询:

db.collection.find({ "field" : { $gt: value1, $lt: value2 } } );

其中 value1 和 value2 代表您通过 ObjectId(Date time)

ObjectId 实例>

The MongoDB documentation recommends extracting insertion times from the ObjectId rather than having a separate time field. Does anyone know how to do this with Spring Data MongoDB?

In particular, I'd like to query for documents inserted in a specific date range.

解决方案

It's easy to get times from an ObjectId... however you do NOT get ms precision.

org.bson.types.ObjectId has 2 methods you can use on it: getTimeSecond() and getTime() (same as `getTimeSecond() * 1000L). These will get your a unix timestamp.

I haven't used MongoDB with Spring - but if you can get your hands on the actual ObjectId instance its as simple as calling a one of the methods above.

Now - to query for documents in a time range you have to go backwards and create ObjectId objects based on a timestamp. Again - this is simple - the ObjectId has a constructor can do this for you:

ObjectId(Date time)

So - create 2 ObjectId instances that represent your min and max time bounds then do a query like:

db.collection.find({ "field" : { $gt: value1, $lt: value2 } } );

where value1 and value2 represent the ObjectId instance you created via ObjectId(Date time)

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