(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:
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 driver automatically
generates an ObjectId for the _id
field.
Using ObjectIds for the _id
field provides the following
additional benefits:
_id
field that stores ObjectId values is roughly equivalent to sorting by creation time.
Version | Description |
---|---|
1.3.0 |
Renamed from Implements MongoDB\BSON\ObjectIdInterface. |
1.2.0 | Implements Serializable and JsonSerializable. |