Query Cosmos DB Data as a SQL Server Database in Node.js

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

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

Configure Cosmos DB Connectivity for NodeJS

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

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

2. Select "Cosmos DB" from the Add Connection panel

3. Enter the necessary authentication properties to connect to Cosmos DB.

   To obtain the connection string needed to connect to a Cosmos DB account using the SQL API, log in to the Azure Portal, select Azure Cosmos DB, and select your account. In the Settings section, click Connection String and set the following values:

   • AccountEndpoint: The Cosmos DB account URL from the Keys blade of the Cosmos DB account
   • AccountKey: In the Azure portal, navigate to the Cosmos DB service and select your Azure Cosmos DB account. From the resource menu, go to the Keys page. Find the PRIMARY KEY value and set AccountKey to this value.
   
4. Click Create & Test
5. Navigate to the Permissions tab in the Add Cosmos DB Connection page and update the User-based permissions.

Add a Personal Access Token

When connecting to Connect Cloud 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 Cloud. 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 Cloud 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 Cosmos DB data from Node.js.

Query Cosmos DB from Node.js

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

• server: tds.cdata.com
• port: 14333
• user: a Connect Cloud user (e.g. [email protected])
• password: the PAT for the above user
• database: The connection you configured for Cosmos DB (CosmosDB1)

Connect to Cosmos DB 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: 'CosmosDB1'
	}
}

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

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