Connect to CockroachDB Data in JRuby

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

Configure a JDBC Connection to CockroachDB 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 CockroachDB\lib).

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

Set the following to connect to CockroachDB.

• Server: The host name or IP address of the server.
• Port: The port number of the CockroachDB server. If not specified, the default port is 26257.
• Database: The name of the Cockroach database. If not specified, you connect to the user's default database.
• User: The Cockroach DB user account used to authenticate.
• Password: The password used to authenticate the user.

Built-in Connection String Designer

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

java -jar cdata.jdbc.cockroachdb.jar

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

Below is a typical JDBC connection string for CockroachDB:

jdbc:cockroachdb:User=root;Password=root;Database=system;Server=localhost;Port=26257

Create a JRuby App with Connectivity to CockroachDB Data

Create a new Ruby file (for example: CockroachDBSelect.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 CockroachDB 2018/lib/cdata.jdbc.cockroachdb.jar'

url = "jdbc:cockroachdb:User=root;Password=root;Database=system;Server=localhost;Port=26257"
conn = java.sql.DriverManager.getConnection(url)
stmt = conn.createStatement
rs = stmt.executeQuery("SELECT ShipName, ShipCity FROM Orders")
while (rs.next) do
 puts rs.getString(1) + ' ' + rs.getString(2)
end

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

jruby -S CockroachDBSelect.rb

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