Query Azure Data Lake Storage Data as a MySQL Database in Node.js

You can use the SQL Gateway from the ODBC Driver for Azure Data Lake Storage to query Azure Data Lake Storage 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 Azure Data Lake Storage 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.

Authenticating to a Gen 1 DataLakeStore Account

Gen 1 uses OAuth 2.0 in Azure AD for authentication.

For this, an Active Directory web application is required. You can create one as follows:

1. Sign in to your Azure Account through the .
2. Select "Azure Active Directory".
3. Select "App registrations".
4. Select "New application registration".
5. Provide a name and URL for the application. Select Web app for the type of application you want to create.
6. Select "Required permissions" and change the required permissions for this app. At a minimum, "Azure Data Lake" and "Windows Azure Service Management API" are required.
7. Select "Key" and generate a new key. Add a description, a duration, and take note of the generated key. You won't be able to see it again.

To authenticate against a Gen 1 DataLakeStore account, the following properties are required:

• Schema: Set this to ADLSGen1.
• Account: Set this to the name of the account.
• OAuthClientId: Set this to the application Id of the app you created.
• OAuthClientSecret: Set this to the key generated for the app you created.
• TenantId: Set this to the tenant Id. See the property for more information on how to acquire this.
• Directory: Set this to the path which will be used to store the replicated file. If not specified, the root directory will be used.

Authenticating to a Gen 2 DataLakeStore Account

To authenticate against a Gen 2 DataLakeStore account, the following properties are required:

• Schema: Set this to ADLSGen2.
• Account: Set this to the name of the account.
• FileSystem: Set this to the file system which will be used for this account.
• AccessKey: Set this to the access key which will be used to authenticate the calls to the API. See the property for more information on how to acquire this.
• Directory: Set this to the path which will be used to store the replicated file. If not specified, the root directory will be used.

Configure the SQL Gateway

See the SQL Gateway Overview to set up connectivity to Azure Data Lake Storage 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 Azure Data Lake Storage from Node.js

The following example shows how to define a connection and execute queries to Azure Data Lake Storage 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 Azure Data Lake Storage data and start executing queries with the code below:

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

connection.end();