ObjectID()

Constructor

Create a new ObjectID instance

class ObjectID()

Arguments:

• id (string) – Can be a 24 byte hex string, 12 byte binary string or a Number.

Returns:

object instance of ObjectID.

toHexString

Return the ObjectID id as a 24 byte hex string representation

toHexString()

Returns:string return the 24 byte hex string representation.

Examples

Generate a 24 character hex string representation of the ObjectID

var Db = require('mongodb').Db,
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    ReplSetServers = require('mongodb').ReplSetServers,
    ObjectID = require('mongodb').ObjectID,
    Binary = require('mongodb').Binary,
    GridStore = require('mongodb').GridStore,
    Grid = require('mongodb').Grid,
    Code = require('mongodb').Code,
    BSON = require('mongodb').pure().BSON,
    assert = require('assert');

// Create a new ObjectID
var objectId = new ObjectID();
// Verify that the hex string is 24 characters long
assert.equal(24, objectId.toHexString().length);

equals

Compares the equality of this ObjectID with <code>otherID</code>.

equals(otherID)

Arguments:

• otherID (object) – ObjectID instance to compare against.

Returns:

bool the result of comparing two ObjectID’s

Examples

Compare two different ObjectID’s using the equals method

var Db = require('mongodb').Db,
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    ReplSetServers = require('mongodb').ReplSetServers,
    ObjectID = require('mongodb').ObjectID,
    Binary = require('mongodb').Binary,
    GridStore = require('mongodb').GridStore,
    Grid = require('mongodb').Grid,
    Code = require('mongodb').Code,
    BSON = require('mongodb').pure().BSON,
    assert = require('assert');

// Create a new ObjectID
var objectId = new ObjectID();
// Create a new ObjectID Based on the first ObjectID
var objectId2 = new ObjectID(objectId.id);
// Create another ObjectID
var objectId3 = new ObjectID();
// objectId and objectId2 should be the same
assert.ok(objectId.equals(objectId2));
// objectId and objectId2 should be different
assert.ok(!objectId.equals(objectId3));

getTimestamp

Returns the generation date (accurate up to the second) that this ID was generated.

getTimestamp()

Returns:date the generation date

Examples

Generate 12 byte binary string representation using a second based timestamp or default value

var Db = require('mongodb').Db,
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    ReplSetServers = require('mongodb').ReplSetServers,
    ObjectID = require('mongodb').ObjectID,
    Binary = require('mongodb').Binary,
    GridStore = require('mongodb').GridStore,
    Grid = require('mongodb').Grid,
    Code = require('mongodb').Code,
    BSON = require('mongodb').pure().BSON,
    assert = require('assert');

// Get a timestamp in seconds
var timestamp = Math.floor(new Date().getTime()/1000);
// Create a date with the timestamp
var timestampDate = new Date(timestamp*1000);

// Create a new ObjectID with a specific timestamp
var objectId = new ObjectID(timestamp);

// Get the timestamp and validate correctness
assert.equal(timestampDate.toString(), objectId.getTimestamp().toString());

ObjectID.createFromTime

Creates an ObjectID from a second based number, with the rest of the ObjectID zeroed out. Used for comparisons or sorting the ObjectID.

ObjectID.createFromTime(time)

Arguments:

• time (number) – an integer number representing a number of seconds.

Returns:

objectid return the created ObjectID

Examples

Show the usage of the Objectid createFromTime function

var Db = require('mongodb').Db,
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    ReplSetServers = require('mongodb').ReplSetServers,
    ObjectID = require('mongodb').ObjectID,
    Binary = require('mongodb').Binary,
    GridStore = require('mongodb').GridStore,
    Grid = require('mongodb').Grid,
    Code = require('mongodb').Code,
    BSON = require('mongodb').pure().BSON,
    assert = require('assert');

var objectId = ObjectID.createFromTime(1);
assert.equal("000000010000000000000000", objectId.toHexString());

ObjectID.createFromHexString

Creates an ObjectID from a hex string representation of an ObjectID.

ObjectID.createFromHexString(hexString)

Arguments:

• hexString (string) – create a ObjectID from a passed in 24 byte hexstring.

Returns:

objectid return the created ObjectID

Examples

Convert a ObjectID into a hex string representation and then back to an ObjectID

var Db = require('mongodb').Db,
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    ReplSetServers = require('mongodb').ReplSetServers,
    ObjectID = require('mongodb').ObjectID,
    Binary = require('mongodb').Binary,
    GridStore = require('mongodb').GridStore,
    Grid = require('mongodb').Grid,
    Code = require('mongodb').Code,
    BSON = require('mongodb').pure().BSON,
    assert = require('assert');

// Create a new ObjectID
var objectId = new ObjectID();
// Convert the object id to a hex string
var originalHex = objectId.toHexString();
// Create a new ObjectID using the createFromHexString function
var newObjectId = new ObjectID.createFromHexString(originalHex)
// Convert the new ObjectID back into a hex string using the toHexString function
var newHex = newObjectId.toHexString();
// Compare the two hex strings
assert.equal(originalHex, newHex);

ObjectID.isValid

Checks if a value is a valid bson ObjectId

ObjectID.isValid()

Returns:boolean return true if the value is a valid bson ObjectId, return false otherwise.