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Get the Report →Connect to Cassandra Data in Ruby
Connect to Cassandra data in Ruby with ruby-dbi, dbd-odbc, and ruby-odbc.
The CData ODBC Driver for Cassandra makes it easy to integrate connectivity to live Cassandra data in Ruby. This article shows how to create a simple Ruby app that connects to Cassandra data, executes a query, and displays the results.
Create an ODBC Connection to Cassandra 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 Server, Port, and Database connection properties to connect to Cassandra. Additionally, to use internal authentication set the User and Password connection properties.
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 Cassandra Data
Create a new Ruby file (for example: CassandraSelect.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 Cassandra Source','','')
#execute a SELECT query and store the result set
resultSet = cnxn.execute("SELECT City, SUM(TotalDue) FROM Customer GROUP BY City")
#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 Cassandra data with Ruby. To do so, simply run your file from the command line:
ruby CassandraSelect.rb
Writing SQL-92 queries to Cassandra allows you to quickly and easily incorporate Cassandra data into your own Ruby applications. Download a free trial today!