Connect to Amazon DynamoDB Data in Ruby

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

Create an ODBC Connection to Amazon DynamoDB 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.

The connection to Amazon DynamoDB is made using your AccessKey, SecretKey, and optionally your Domain and Region. Your AccessKey and SecretKey can be obtained on the security credentials page for your Amazon Web Services account. Your Region will be displayed in the upper left-hand corner when you are logged into DynamoDB.

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 Amazon DynamoDB Data

Create a new Ruby file (for example: AmazonDynamoDBSelect.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 AmazonDynamoDB Source','','')

#execute a SELECT query and store the result set
resultSet = cnxn.execute("SELECT Industry, Revenue FROM Lead")

#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 Amazon DynamoDB data with Ruby. To do so, simply run your file from the command line:

ruby AmazonDynamoDBSelect.rb

Writing SQL-92 queries to Amazon DynamoDB allows you to quickly and easily incorporate Amazon DynamoDB data into your own Ruby applications. Download a free trial today!