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

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

CData Connect AI provides a pure MySQL, cloud-to-cloud interface for Avro, allowing you to easily query live Avro 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 Avro, leveraging server-side processing to quickly return Avro data.

Configure Avro Connectivity for NodeJS

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

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

2. Select "Avro" from the Add Connection panel

3. Enter the necessary authentication properties to connect to Avro. Connect to your local Avro file(s) by setting the URI connection property to the location of the Avro file.
4. Click Save & Test
5. Navigate to the Permissions tab in the Add Avro Connection page and update the User-based 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.
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 Avro data from Node.js.

Query Avro from Node.js

The following example shows how to define a connection and execute queries to Avro 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 Avro (Avro1)

Connect to Avro 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: 'Avro1'
	}
}

sql.connect(config, err => { 
    if(err){
        throw err ;
    }
    new sql.Request().query('SELECT * FROM SampleTable_1', (err, result) => {
        console.dir(result)
    })
        
});

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