The MongoId class
(PECL mongo >=0.8.0)
This extension that defines this class is deprecated. Instead, the MongoDB extension should be used. Alternatives to this class include:
Introduction
A unique identifier created for database objects. If an object is inserted into the database without an _id field, an _id field will be added to it with a MongoId instance as its value. If the data has a naturally occuring unique field (e.g. username or timestamp) it is fine to use this as the _id field instead, and it will not be replaced with a MongoId.
Instances of the MongoId class fulfill the role that autoincrementing does in a relational database: to provide a unique key if the data does not naturally have one. Autoincrementing does not work well with a sharded database, as it is difficult to determine the next number in the sequence. This class fulfills the constraints of quickly generating a value that is unique across shards.
Each MongoId is 12 bytes (making its string form 24 hexadecimal characters). The first four bytes are a timestamp, the next three are a hash of the client machine's hostname, the next two are the two least significant bytes of the process id running the script, and the last three bytes are an incrementing value.
MongoIds are serializable/unserializable. Their serialized form is similar to their string form:
C:7:"MongoId":24:{4af9f23d8ead0e1d32000000}
Class synopsis
Fields
- $id
-
This field contains the string representation of this object.
Note: The property name begins with a $ character. It may be accessed using complex variable parsed syntax (e.g. $mongoId->{'$id'}).
Table of Contents
- MongoId::__construct — Creates a new id
- MongoId::getHostname — Gets the hostname being used for this machine's ids
- MongoId::getInc — Gets the incremented value to create this id
- MongoId::getPID — Gets the process ID
- MongoId::getTimestamp — Gets the number of seconds since the epoch that this id was created
- MongoId::isValid — Check if a value is a valid ObjectId
- MongoId::__set_state — Create a dummy MongoId
- MongoId::__toString — Returns a hexidecimal representation of this id
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-class.mongoid.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.