Connect to Azure Data Lake Storage Data in Ruby

The CData ODBC Driver for Azure Data Lake Storage makes it easy to integrate connectivity to live Azure Data Lake Storage data in Ruby. This article shows how to create a simple Ruby app that connects to Azure Data Lake Storage data, executes a query, and displays the results.

Create an ODBC Connection to Azure Data Lake Storage Data

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

Authenticating to a Gen 1 DataLakeStore Account

Gen 1 uses OAuth 2.0 in Entra ID (formerly 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 "Entra ID" (formerly Azure AD).
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.

Installing Ruby and Necessary Gems

If you do not have Ruby installed, refer to the Ruby installation page. With Ruby installed, you will need to install the ruby-dbi, dbd-odbc, and ruby-odbc gems:

gem install dbi
gem install dbd-odbc
gem install ruby-odbc

Create a Ruby App with Connectivity to Azure Data Lake Storage Data

Create a new Ruby file (for example: ADLSSelect.rb) and open it in a text editor. Copy the following code into your file:

#connect to the DSN
require 'dbi'
cnxn = DBI.connect('DBI:ODBC:CData ADLS Source','','')

#execute a SELECT query and store the result set
resultSet = cnxn.execute("SELECT FullPath, Permission FROM Resources WHERE Type = 'FILE'")

#display the names of the columns
resultSet.column_names.each do |name|
 print name, "\t"
end
puts

#display the results
while row = resultSet.fetch do
 (0..resultSet.column_names.size - 1).each do |n|
 print row[n], "\t"
 end
 puts
end
resultSet.finish

#close the connection
cnxn.disconnect if cnxn

With the file completed, you are ready to display your Azure Data Lake Storage data with Ruby. To do so, simply run your file from the command line:

ruby ADLSSelect.rb

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