Connect to Lakebase Data in JRuby

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

Configure a JDBC Connection to Lakebase 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 Lakebase\lib).

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

• DatabricksInstance: The Databricks instance or server hostname, provided in the format instance-abcdef12-3456-7890-abcd-abcdef123456.database.cloud.databricks.com.
• Server: The host name or IP address of the server hosting the Lakebase database.
• Port (optional): The port of the server hosting the Lakebase database, set to 5432 by default.
• Database (optional): The database to connect to after authenticating to the Lakebase Server, set to the authenticating user's default database by default.

OAuth Client Authentication

To authenicate using OAuth client credentials, you need to configure an OAuth client in your service principal. In short, you need to do the following:

1. Create and configure a new service principal
2. Assign permissions to the service principal
3. Create an OAuth secret for the service principal

For more information, refer to the Setting Up OAuthClient Authentication section in the Help documentation.

OAuth PKCE Authentication

To authenticate using the OAuth code type with PKCE (Proof Key for Code Exchange), set the following properties:

• AuthScheme: OAuthPKCE.
• User: The authenticating user's user ID.

For more information, refer to the Help documentation.

Built-in Connection String Designer

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

java -jar cdata.jdbc.lakebase.jar

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

Below is a typical JDBC connection string for Lakebase:

jdbc:lakebase:DatabricksInstance=lakebase;Server=127.0.0.1;Port=5432;Database=my_database;InitiateOAuth=GETANDREFRESH;

Create a JRuby App with Connectivity to Lakebase Data

Create a new Ruby file (for example: LakebaseSelect.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 Lakebase 2018/lib/cdata.jdbc.lakebase.jar'

url = "jdbc:lakebase:DatabricksInstance=lakebase;Server=127.0.0.1;Port=5432;Database=my_database;InitiateOAuth=GETANDREFRESH;"
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 Lakebase data with JRuby. To do so, simply run your file from the command line:

jruby -S LakebaseSelect.rb

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