Query Cosmos DB Data as a MySQL Database in Node.js

You can use the SQL Gateway from the ODBC Driver for Cosmos DB to query Cosmos DB data through a MySQL interface. Follow the procedure below to start the MySQL remoting service of the SQL Gateway and start querying using Node.js.

Connect to Cosmos DB Data

If you have not already done so, provide values for the required connection properties in the data source name (DSN). You can use the built-in Microsoft ODBC Data Source Administrator to configure the DSN. This is also the last step of the driver installation. See the "Getting Started" chapter in the help documentation for a guide to using the Microsoft ODBC Data Source Administrator to create and configure a DSN.

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.

Configure the SQL Gateway

See the SQL Gateway Overview to set up connectivity to Cosmos DB data as a virtual MySQL database. You will configure a MySQL remoting service that listens for MySQL requests from clients. The service can be configured in the SQL Gateway UI.

Query Cosmos DB from Node.js

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

• Host name or address, and port: The machine and port where the MySQL remoting service is listening for MySQL connections.
• Username and password: The username and password of a user you authorized on the Users tab of the SQL Gateway.
• Database name: The DSN you configured for the MySQL remoting service.

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

var mysql      = require('mysql');
var connection = mysql.createConnection({
  host     : 'localhost',
  database : 'CData CosmosDB Sys',
  port	   : '3306',
  user     : 'mysql_user',
  password : 'test'
});
connection.connect();
connection.query('SELECT * FROM Customers', function(err, rows, fields) {
  if (err) throw err;
  console.log(rows);
});

connection.end();