Connect to Cloudant Data in Ruby

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

Create an ODBC Connection to Cloudant 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.

Set the following connection properties to connect to Cloudant:

• User: Set this to your username.
• Password: Set this to your password.

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 Cloudant Data

Create a new Ruby file (for example: CloudantSelect.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 Cloudant Source','','')

#execute a SELECT query and store the result set
resultSet = cnxn.execute("SELECT MovieRuntime, MovieRating FROM Movies")

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

ruby CloudantSelect.rb

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