Connect to PostgreSQL Data in Ruby



Connect to PostgreSQL data in Ruby with ruby-dbi, dbd-odbc, and ruby-odbc.

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

Create an ODBC Connection to PostgreSQL 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.

To connect to PostgreSQL, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you wish to use to authenticate to the server. If the Database property is not specified, the data provider connects to the user's default database.

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 PostgreSQL Data

Create a new Ruby file (for example: PostgreSQLSelect.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 PostgreSQL Source','','') #execute a SELECT query and store the result set resultSet = cnxn.execute("SELECT ShipName, ShipCity FROM Orders") #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 PostgreSQL data with Ruby. To do so, simply run your file from the command line:

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

Ready to get started?

Download a free trial of the PostgreSQL ODBC Driver to get started:

 Download Now

Learn more:

PostgreSQL Icon PostgreSQL ODBC Driver

The PostgreSQL ODBC Driver is a powerful tool that allows you to connect with live PostgreSQL data, directly from any applications that support ODBC connectivity.

Access PostgreSQL databases from virtually anywhere through a standard ODBC Driver interface.