The MongoDB\BSON\ObjectId class

(mongodb >=1.0.0)

Introduction

BSON type for an » ObjectId. The value consists of 12 bytes, where the first four bytes are a timestamp that reflect the ObjectId's creation. Specifically, the value consists of:

a 4-byte value representing the seconds since the Unix epoch,
a 5-byte random number unique to a machine and process, and
a 3-byte counter, starting with a random value.

In MongoDB, each document stored in a collection requires a unique _id field that acts as a primary key. If an inserted document omits the _id field, the extension automatically generates an ObjectId for the _id field.

Using ObjectIds for the _id field provides the following additional benefits:

The creation time of the ObjectId may be accessed using the MongoDB\BSON\ObjectId::getTimestamp() method.
Sorting on an _id field that stores ObjectId values is roughly equivalent to sorting by creation time.

Class synopsis

final class MongoDB\BSON\ObjectId implements MongoDB\BSON\ObjectIdInterface, MongoDB\BSON\Type, JsonSerializable, Stringable {

/* Methods */

final public function __construct(?string $id = null)

final public function getTimestamp(): int

final public function jsonSerialize(): mixed

final public function __toString(): string

}

Changelog

Version	Description
PECL mongodb 2.0.0	This class no longer implements the Serializable interface.
PECL mongodb 1.12.0	Implements Stringable for PHP 8.0+.
PECL mongodb 1.3.0	Renamed from `MongoDB\BSON\ObjectID` to `MongoDB\BSON\ObjectId`. Implements MongoDB\BSON\ObjectIdInterface.
PECL mongodb 1.2.0	Implements Serializable and JsonSerializable.

MongoDB\BSON\ObjectId::__construct — Construct a new ObjectId
MongoDB\BSON\ObjectId::getTimestamp — Returns the timestamp component of this ObjectId
MongoDB\BSON\ObjectId::jsonSerialize — Returns a representation that can be converted to JSON
MongoDB\BSON\ObjectId::__toString — Returns the hexadecimal representation of this ObjectId

The MongoDB\BSON\ObjectId class

Introduction

Class synopsis

Changelog

Table of Contents