mongodb id 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

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

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:

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,

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

In addition to the tangle of queries, the rest are relatively simple! In fact, when I learned how to add, delete, modify, and query mongodb command lines, I also tried it one by one based on the examples on the official website, so please feel free

In addition to the tangle of queries, the rest are relatively simple! In fact, when I learned how to add, delete, modify, and query mongodb command lines, I also tried it one by one based on the examples on the official website, so please feel free

Original: MongoDB Data summaryThe previous Redis Data summary topic is very popular, here the MongoDB series of information is also a simple collation. Hope to be useful to everyone. Last update time: 2013-04-22What is 1.MongoDB? MongoDB