mongodb objectid

ObjectId IntroductionIn MongoDB, a unique _ id field is required to store documents in collections as the primary key. By default, ObjectId is used to define the _ id, because the definition of ObjectId is short enough to maintain uniqueness as much

The recent transformation of two applications, a series of problems in the online process (part of which is due to objectid misunderstanding) first to understand the following objectid: TimeStampThe first 4 bits is a UNIX timestamp, is an int

The recent transformation of two applications, a series of problems in the online process (part of which is due to objectid misunderstanding)first to understand the following objectid:TimeStampThe first 4 bits is a UNIX timestamp, is an int category,

Mongodb entry-8 query 3 continue to learn about mongodb query $ or $ nor $ or, or the meaning is identified as long as there is a match. $ nor is opposite to $ or, as long as $ or can be found as the removed part. [html] db. user. find () {_ id:

_ID and ObjectidThe document stored in MongoDB must have a "_id" key. The value of this key can be any type, and the default is a Objectid object.Within a collection, each collection has a unique "_id" value to ensure that each document within the

Zookeeper _ Id and ObjectIdThe document stored in MongoDB must have a "_ id" key. The value of this key can be of any type and is an ObjectId object by default.In a set, each set has a unique "_ id" value to ensure that each document in the set is

Objectid is the default type for "_id". It is designed to be light-weight, and different machines can easily generate it with a globally unique homogeneous method.This is the main reason that MongoDB uses objectid instead of other more conventional

Statement: The article is mainly from the "MongoDB actual Combat" a book, the main want to learn MongoDB knowledge through the book, deepen understanding, so write in their own blog, as a record, in the final chapter, there will be a collection of

One. MongoDB Insert Document Insert () methodTo insert data into a MongoDB collection, you need to use the MongoDB Insert () or Save () method.GrammarThe basic syntax for the Insert () command is as follows:>db. Collection_name.insert

To complete the requirements in this introduction, we start with the objectid of MONGO, we know that the first four bytes of Objectid are timestamps, then we can filter the records in Mongodump-q. If you do not understand the structure of the MONGO