Connect to AlloyDB Data in JRuby

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

Configure a JDBC Connection to AlloyDB 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 AlloyDB\lib).

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

The following connection properties are usually required in order to connect to AlloyDB.

• Server: The host name or IP of the server hosting the AlloyDB database.
• User: The user which will be used to authenticate with the AlloyDB server.
• Password: The password which will be used to authenticate with the AlloyDB server.

You can also optionally set the following:

• Database: The database to connect to when connecting to the AlloyDB Server. If this is not set, the user's default database will be used.
• Port: The port of the server hosting the AlloyDB database. This property is set to 5432 by default.

Authenticating with Standard Authentication

Standard authentication (using the user/password combination supplied earlier) is the default form of authentication.

No further action is required to leverage Standard Authentication to connect.

Authenticating with pg_hba.conf Auth Schemes

There are additional methods of authentication available which must be enabled in the pg_hba.conf file on the AlloyDB server.

Find instructions about authentication setup on the AlloyDB Server here.

Authenticating with MD5 Authentication

This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to md5.

Authenticating with SASL Authentication

This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to scram-sha-256.

Authenticating with Kerberos

The authentication with Kerberos is initiated by AlloyDB Server when the ∏ is trying to connect to it. You should set up Kerberos on the AlloyDB Server to activate this authentication method. Once you have Kerberos authentication set up on the AlloyDB Server, see the Kerberos section of the help documentation for details on how to authenticate with Kerberos.

Built-in Connection String Designer

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

java -jar cdata.jdbc.alloydb.jar

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

Below is a typical JDBC connection string for AlloyDB:

jdbc:alloydb:User=alloydb;Password=admin;Database=alloydb;Server=127.0.0.1;Port=5432

Create a JRuby App with Connectivity to AlloyDB Data

Create a new Ruby file (for example: AlloyDBSelect.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 AlloyDB 2018/lib/cdata.jdbc.alloydb.jar'

url = "jdbc:alloydb:User=alloydb;Password=admin;Database=alloydb;Server=127.0.0.1;Port=5432"
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 AlloyDB data with JRuby. To do so, simply run your file from the command line:

jruby -S AlloyDBSelect.rb

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