Connect an application

YSQL
YCQL

YugabyteDB Node.js Driver

YugabyteDB Node.js Driver for YCQL is based on DataStax Node.js Driver for YCQL with additional smart driver features.

YugabyteDB Aeon

To use the driver's partition-aware load balancing feature in a YugabyteDB Aeon cluster, applications must be deployed in a VPC that has been peered with the cluster VPC so that they have access to all nodes in the cluster. For more information, refer to Using YCQL drivers with YugabyteDB Aeon.

Install the Yugabyte Node.js Driver for YCQL

To install the YugabyteDB Node.js driver for YCQL, run the following command:

$ npm install yb-ycql-driver

Create the sample Node.js application

Prerequisites

This tutorial assumes that you have:

installed YugabyteDB and created a cluster. Refer to Quick start.
installed a recent version of Node.js.
installed the async utility to work with asynchronous Javascript.

To install the async utility, run the following command:

$ npm install --save async

Write the sample Node.js application

Create a file yb-cql-helloworld.js and add the following content to it.

const ycql = require('yb-ycql-driver');
const async = require('async');
const assert = require('assert');

// Create a YB CQL client.
// DataStax Nodejs 4.0 loadbalancing default is TokenAwarePolicy with child DCAwareRoundRobinPolicy
// Need to provide localDataCenter option below or switch to RoundRobinPolicy
const loadBalancingPolicy = new ycql.policies.loadBalancing.RoundRobinPolicy ();
const client = new ycql.Client({ contactPoints: ['127.0.0.1'], policies : { loadBalancing : loadBalancingPolicy }});

async.series([
  function connect(next) {
    client.connect(next);
  },
  function createKeyspace(next) {
    console.log('Creating keyspace ybdemo');
    client.execute('CREATE KEYSPACE IF NOT EXISTS ybdemo;', next);
  },
  function createTable(next) {
    // The create table statement.
    const create_table = 'CREATE TABLE IF NOT EXISTS ybdemo.employee (id int PRIMARY KEY, ' +
                                                                     'name varchar, ' +
                                                                     'age int, ' +
                                                                     'language varchar, ' +
                                                                     'location jsonb);';
    // Create the table.
    console.log('Creating table employee');
    client.execute(create_table, next);
  },
  function insert(next) {
    // Create a variable with the insert statement.
    const insert = "INSERT INTO ybdemo.employee (id, name, age, language, location) " +
                                        "VALUES (1, 'John', 35, 'NodeJS', '{ \"city\": \"San Francisco\", \"state\": \"California\", \"lat\": 37.77, \"long\": 122.42 }');";
    // Insert a row with the employee data.
    console.log('Inserting row with: %s', insert)
    client.execute(insert, next);
  },
  function select(next) {

    // Query the row for employee id 1 and print the results to the console.
    const select = 'SELECT name, age, language, location FROM ybdemo.employee WHERE id = 1;';
    client.execute(select, function (err, result) {
      if (err) return next(err);
      var row = result.first();
      const city = row.location.city;
      console.log('Query for id=1 returned: name=%s, age=%d, language=%s, city=%s',
                                            row.name, row.age, row.language, city);
      next();
    });
  }
], function (err) {
  if (err) {
    console.error('There was an error', err.message, err.stack);
  }
  console.log('Shutting down');
  client.shutdown();
});

Run the application

To use the application, run the following command:

$ node yb-cql-helloworld.js

You should see the following output.

Creating keyspace ybdemo
Creating table employee
Inserting row with: INSERT INTO ybdemo.employee (id, name, age, language) VALUES (1, 'John', 35, 'NodeJS');
Query for id=1 returned: name=John, age=35, language=NodeJS
Shutting down