- Tutorials
- Connect to MongoDB
Connect to MongoDB
Use the client.connect
method to connect to a running MongoDB deployment.
Connect to a Single MongoDB Instance
To connect to a single MongoDB instance, specify the URI of the MongoDB instance to connect to.
In the following example, the
URI connection string
specifies connecting to a MongoDB instance that is running on
localhost
using port 27017
. The myproject
indicates the database
to use.
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
// Connection URL
const url = 'mongodb://localhost:27017';
// Database Name
const dbName = 'myproject';
// Create a new MongoClient
const client = new MongoClient(url);
// Use connect method to connect to the Server
client.connect(function(err) {
assert.equal(null, err);
console.log("Connected successfully to server");
const db = client.db(dbName);
client.close();
});
For more information on the URI connection string, see URI Connection String .
Connect to a Replica Set
To connect to a replica set, include a seedlist of replica set members and the name of the replica set in the URI connection string.
In the following example, the connection string specifies two of the replica set members running on localhost:27017
and localhost:27018
and the name of the replica set (foo
).
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
// Connection URL
const url = 'mongodb://localhost:27017,localhost:27018/?replicaSet=foo';
// Database Name
const dbName = 'myproject';
// Create a new MongoClient
const client = new MongoClient(url);
// Use connect method to connect to the Server
client.connect(function(err) {
assert.equal(null, err);
console.log("Connected correctly to server");
const db = client.db(dbName);
client.close();
});
For more information on the URI connection string, see URI Connection String .
Connect to Sharded Cluster
To connect to a sharded cluster, specify the mongos
instance or instances in the URI connection string.
In the following example, the connection string specifies the mongos
instances running on localhost:50000
and localhost:50001
.
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
// Connection URL
const url = 'mongodb://localhost:50000,localhost:50001';
// Database Name
const dbName = 'myproject';
// Create a new MongoClient
const client = new MongoClient(url);
// Use connect method to connect to the Server
client.connect(function(err, client) {
assert.equal(null, err);
console.log("Connected successfully to server");
const db = client.db(dbName);
client.close();
});
For more information on the URI connection string, see URI Connection String .
Connection Options
You can specify various connection settings in the URI Connection String .
For example, you can specify TLS/SSL and authentication setting.
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
const fs = require('fs');
// Read the certificate authority
const ca = [fs.readFileSync(__dirname + "/ssl/ca.pem")];
const cert = fs.readFileSync(__dirname + "/ssl/client.pem");
// Connection URL
const url = 'mongodb://dave:password@localhost:27017?authMechanism=DEFAULT&authSource=db&ssl=true"';
// Create a client, passing in additional options
const client = new MongoClient(url, {
sslValidate: true,
sslCA: ca,
sslCert: cert
});
// Use connect method to connect to the server
client.connect(function(err) {
assert.equal(null, err);
console.log("Connected correctly to server");
client.close();
});
For more information on connecting with authentication and TSL/SSL, see:
- Authentication: detailed documentation of the various ways to specify authentication credentials
- TLS/SSL: Detailed documentation of the various ways to specify the properties of an TLS/SSL connection
For more information on the connection options:
- URI Connection String: MongoDB connection string URI.
- Connection Settings: Reference on the driver-specific connection settings.