Query Elasticsearch Data as a SQL Server Database in Node.js

You can use CData Connect AI to query Elasticsearch data through a SQL Server interface. Follow the procedure below to create a virtual database for Elasticsearch in Connect AI and start querying using Node.js.

CData Connect AI provides a pure MySQL, cloud-to-cloud interface for Elasticsearch, allowing you to easily query live Elasticsearch data in Node.js — without replicating the data to a natively supported database. As you query data in Node.js, CData Connect AI pushes all supported SQL operations (filters, JOINs, etc) directly to Elasticsearch, leveraging server-side processing to quickly return Elasticsearch data.

Getting Started

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Configure Elasticsearch Connectivity for NodeJS

Connectivity to Elasticsearch from NodeJS is made possible through CData Connect AI. To work with Elasticsearch data from NodeJS, we start by creating and configuring a Elasticsearch connection.

1. Log into Connect AI, click Sources, and then click Add Connection
👁 Adding a Connection

2. Select "Elasticsearch" from the Add Connection panel
👁 Selecting a data source

3. Enter the necessary authentication properties to connect to Elasticsearch.

   Set the Server and Port connection properties to connect. To authenticate, set the User and Password properties, PKI (public key infrastructure) properties, or both. To use PKI, set the SSLClientCert, SSLClientCertType, SSLClientCertSubject, and SSLClientCertPassword properties.

   The data provider uses X-Pack Security for TLS/SSL and authentication. To connect over TLS/SSL, prefix the Server value with 'https://'. Note: TLS/SSL and client authentication must be enabled on X-Pack to use PKI.

   Once the data provider is connected, X-Pack will then perform user authentication and grant role permissions based on the realms you have configured.

   👁 Configuring a connection (Salesforce is shown)
   
4. Click Save & Test
5. Navigate to the Permissions tab in the Add Elasticsearch Connection page and update the User-based permissions. 👁 Updating permissions
   

Add a Personal Access Token

When connecting to Connect AI through the REST API, the OData API, or the Virtual SQL Server, a Personal Access Token (PAT) is used to authenticate the connection to Connect AI. It is best practice to create a separate PAT for each service to maintain granularity of access.

1. Click on the Gear icon () at the top right of the Connect AI app to open the settings page.
2. On the Settings page, go to the Access Tokens section and click Create PAT.
3. Give the PAT a name and click Create. 👁 Creating a new PAT
   
4. The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

With the connection configured and a PAT generated, you are ready to connect to Elasticsearch data from Node.js.

Query Elasticsearch from Node.js

The following example shows how to define a connection and execute queries to Elasticsearch with the SQL Server module. You will need the following information:

• server: tds.cdata.com
• port: 14333
• user: a Connect AI user (e.g. [email protected])
• password: the PAT for the above user
• database: The connection you configured for Elasticsearch (Elasticsearch1)

Connect to Elasticsearch data and start executing queries with the code below:

var sql = require('mssql')
var config = {
	server: 'tds.cdata.com',
	port: 14333, 
	user: '[email protected]', //update me
	password: 'CONNECT_USER_PAT', //update me	
	options: {
		encrypt: true,
		database: 'Elasticsearch1'
	}
}

sql.connect(config, err => { 
 if(err){
 throw err ;
 }
 new sql.Request().query('SELECT * FROM Orders', (err, result) => {
 console.dir(result)
 })
 
});

sql.on('error', err => {
 console.log("SQL Error: " ,err);
})