CascadiaPHP 2024

The MongoDB\BSON\ObjectId class

(mongodb >=1.0.0)


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.


/* メソッド */
final public __construct(?string $id = null)
final public getTimestamp(): int
final public jsonSerialize(): mixed
final public serialize(): string
final public __toString(): string
final public unserialize(string $data): void


バージョン 説明
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.


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User Contributed Notes 2 notes

naip1984 at gmail dot com
6 years ago
I struggled for awhile to identify the way to find() using a ObjectID

This seems to work, I hope this helps someone else out.

$mongoId = '5a2493c33c95a1281836eb6a';

$collection->find(['_id'=> new MongoDB\BSON\ObjectId("$mongoId")]);

I found it here:

Note this is for the PHP library, not the legacy library.
Mike T
6 years ago
Worth noting this will throw an InvalidArgumentException if string is not in the correct format
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