Getting started

Getting started with the DataStax Node.js driver for Apache Cassandra.

Connecting to a cluster

To connect to a Cassandra cluster, you need to provide at least 1 node of the cluster, if there are more nodes than the ones provided, the driver will discover all the nodes in the cluster after it connects to the first node.

Typically you create only 1 Client instance for a given Cassandra cluster and use it across your application.

const cassandra = require('cassandra-driver');
const client = new cassandra.Client({ contactPoints: ['host1'] });
client.connect(function (err) {

At this point, the driver will be connected to one of the contact points and discovered the rest of the nodes in your cluster.

Even though calling #connect() is not required (the execute method internally calls to connect), it is recommended you call to #connect() on application startup, this way you can ensure that you start your app once your are connected to your Cassandra cluster.

Retrieving data

The #execute() method can be used to send a CQL query to a Cassandra node, a simple way to use would be to provide a query and a callback.

const query = "SELECT name, email, birthdate FROM users WHERE key = 'mick-jagger'";
client.execute(query, function (err, result) {
  var user = result.first();
  //The row is an Object with column names as property keys. 
  console.log('My name is %s and my email is %s',,;

Using query parameters and prepared statements

Instead of hard coding your parameters in your query, you can use parameter markers in your queries and provide the parameters as an Array.

const query = 'SELECT name, email, birthdate FROM users WHERE key = ?';
client.execute(query, ['mick-jagger'], callback);

This way you can reuse the query and forget about escaping / stringifying the parameters in your query.

Additionally, if you plan to reuse a query within your application (it is generally the case, your parameter value changes but there is only a small number of different queries for a given schema), you can benefit from using prepared statements.

Using prepared statements increases performance compared to plain executes, especially for repeated queries as the query only needs to be parsed once by the Cassandra node. It has the additional benefit of providing metadata of the parameters to the driver, allowing better type mapping between javascript and Cassandra without the need of additional info (hints) from the user.

const query = 'SELECT name, email, birthdate FROM users WHERE key = ?';
//Set the prepare flag in your queryOptions
client.execute(query, ['mick-jagger'], { prepare: true }, callback);

See the data types documentation to see how CQL types are mapped to javascript types.

Inserting data

You can use the #execute() method to execute any CQL query.

const query = 'INSERT INTO users (key, name, email, birthdate) VALUES (?, ?, ?)';
const params = ['mick-jagger', 'Sir Mick Jagger', '', new Date(1943, 6, 26)];
client.execute(query, params, { prepare: true }, function (err) {
  //Inserted in the cluster

Setting the consistency level

To specify how consistent the data must be for a given read or write operation, you can set the consistency level per query

client.execute(query, params, { consistency: types.consistencies.quorum }, function (err) {
  //This callback will be called once it has been written in the number of replicas
  //satisfying the consistency level specified.

Or you can provide a default consistency level for all your queries when creating the Client instance (defaults to one).

const client = new Client({ queryOptions: { consistency: types.consistencies.quorum } });

Authentication (optional)

Using an authentication provider on an auth-enabled Cassandra cluster:

const authProvider = new cassandra.auth.PlainTextAuthProvider('my_user', 'p@ssword1!');
//Set the auth provider in the clientOptions when creating the Client instance
const client = new Client({ authProvider: authProvider });