Class: MongoClient

Extends

• EventEmitter

Methods

staticMongoClient.connect(url, options){Promise.<MongoClient>}

lib/mongo_client.js, line 417

Connect to MongoDB using a url as documented at

docs.mongodb.org/manual/reference/connection-string/

Note that for replicasets the replicaSet query parameter is required in the 2.0 driver

Name	Type	Description
url	string	The connection URI string
options	MongoClientOptions	optional Optional settings

Returns:

Promise if no callback passed

close(force, callback){Promise}

lib/mongo_client.js, line 303

Close the db and its underlying connections

Name	Type	Default	Description
force	boolean	false	optional Force close, emitting no events
callback	Db~noResultCallback		optional The result callback

Returns:

Promise if no callback passed

connect(callback){Promise.<MongoClient>}

lib/mongo_client.js, line 274

Connect to MongoDB using a url as documented at

docs.mongodb.org/manual/reference/connection-string/

Note that for replicasets the replicaSet query parameter is required in the 2.0 driver

Name	Type	Description
callback	MongoClient~connectCallback	optional The command result callback

Returns:

Promise if no callback passed

db(dbName, options){Db}

lib/mongo_client.js, line 354

Create a new Db instance sharing the current socket connections. Be aware that the new db instances are
related in a parent-child relationship to the original instance so that events are correctly emitted on child
db instances. Child db instances are cached so performing db('db1') twice will return the same instance.
You can control these behaviors with the options noListener and returnNonCachedInstance.

Name	Type	Description
dbName	string	optional The name of the database we want to use. If not provided, use database name from connection string.
options	object	optional Optional settings. Name Type Default Description noListener boolean false optional Do not make the db an event listener to the original connection. returnNonCachedInstance boolean false optional Control if you want to return a cached instance or have a new one created

isConnected(options){boolean}

lib/mongo_client.js, line 397

Check if MongoClient is connected

Name	Type	Description
options	object	optional Optional settings. Name Type Default Description noListener boolean false optional Do not make the db an event listener to the original connection. returnNonCachedInstance boolean false optional Control if you want to return a cached instance or have a new one created

Deprecated

• Yes

startSession(options){ClientSession}

lib/mongo_client.js, line 435

Starts a new session on the server

Name	Type	Description
options	SessionOptions	optional optional settings for a driver session

Returns:

newly established session

watch(pipeline, options){ChangeStream}

lib/mongo_client.js, line 499

Create a new Change Stream, watching for new changes (insertions, updates, replacements, deletions, and invalidations) in this cluster. Will ignore all changes to system collections, as well as the local, admin,
and config databases.

Name	Type	Description
pipeline	Array	optional An array of aggregation pipeline stages through which to pass change stream documents. This allows for filtering (using $match) and manipulating the change stream documents.
options	object	optional Optional settings Name Type Default Description fullDocument string 'default' optional Allowed values: ‘default’, ‘updateLookup’. When set to ‘updateLookup’, the change stream will include both a delta describing the changes to the document, as well as a copy of the entire document that was changed from some time after the change occurred. resumeAfter object optional Specifies the logical starting point for the new change stream. This should be the _id field from a previously returned change stream document. maxAwaitTimeMS number optional The maximum amount of time for the server to wait on new documents to satisfy a change stream query batchSize number 1000 optional The number of documents to return per batch. See aggregation documentation. collation object optional Specify collation settings for operation. See aggregation documentation. readPreference ReadPreference optional The read preference. See read preference documentation. startAtOperationTime Timestamp optional receive change events that occur after the specified timestamp session ClientSession optional optional session to use for this operation

Since:

• 3.1.0

Returns:

ChangeStream instance.

withSession(options, operation){Promise}

lib/mongo_client.js, line 454

Runs a given operation with an implicitly created session. The lifetime of the session
will be handled without the need for user interaction.

NOTE: presently the operation MUST return a Promise (either explicit or implicity as an async function)

Name	Type	Description
options	Object	optional Optional settings to be appled to implicitly created session
operation	function	An operation to execute with an implicitly created session. The signature of this MUST be (session) => {}

Type Definitions

connectCallback(error, client)

lib/mongo_client.js, line 256

The callback format for results

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
client	MongoClient	The connected client.