Connect to HarperDB Data in JRuby

JRuby is a high-performance, stable, fully threaded Java implementation of the Ruby programming language. The CData JDBC Driver for HarperDB makes it easy to integrate connectivity to live HarperDB data in JRuby. This article shows how to create a simple JRuby app that connects to HarperDB data, executes a query, and displays the results.

Configure a JDBC Connection to HarperDB Data

Before creating the app, note the installation location for the JAR file for the JDBC Driver (typically C:\Program Files\CData\CData JDBC Driver for HarperDB\lib).

JRuby natively supports JDBC, so you can easily connect to HarperDB and execute SQL queries. Initialize the JDBC connection with the getConnection function of the java.sql.DriverManager class.

Set the Server, User, and Password connection properties to connect to HarperDB. Set UseSSL to secure connections with TLS/SSL.

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the HarperDB JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

java -jar cdata.jdbc.harperdb.jar

Fill in the connection properties and copy the connection string to the clipboard.

Below is a typical JDBC connection string for HarperDB:

jdbc:harperdb:Server=127.0.0.1;User=admin;Password=1234;

Create a JRuby App with Connectivity to HarperDB Data

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

require 'java'
require 'rubygems'
require 'C:/Program Files/CData/CData JDBC Driver for HarperDB 2018/lib/cdata.jdbc.harperdb.jar'

url = "jdbc:harperdb:Server=127.0.0.1;User=admin;Password=1234;"
conn = java.sql.DriverManager.getConnection(url)
stmt = conn.createStatement
rs = stmt.executeQuery("SELECT City, CompanyName FROM Customers")
while (rs.next) do
 puts rs.getString(1) + ' ' + rs.getString(2)
end

With the file completed, you are ready to display your HarperDB data with JRuby. To do so, simply run your file from the command line:

jruby -S HarperDBSelect.rb

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