Connect to Alchemy Data in JRuby

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

Configure a JDBC Connection to Alchemy 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 Alchemy\lib).

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

Start by setting the Profile connection property to the location of the Alchemy Profile on disk (e.g. C:\profiles\Alchemy.apip). Next, set the ProfileSettings connection property to the connection string for Alchemy (see below).

Alchemy API Profile Settings

Alchemy uses API key authentication. The API key is supplied in the request URL path. To obtain an API key:

1. Sign in to your Alchemy account at https://dashboard.alchemy.com.
2. Open an existing app or create a new one.
3. Copy the app's API key from the API Key dialog.

After obtaining your API key, set the following connection properties:

• AuthScheme: Set this to APIKey.
• Network: Optional. The blockchain network slug for NFT API requests (for example, eth-mainnet, base-mainnet, polygon-mainnet). Defaults to eth-mainnet.

Set the following in the ProfileSettings connection property:

• APIKey: Set this to your Alchemy app API key.

Built-in Connection String Designer

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

java -jar cdata.jdbc.api.jar

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

Below is a typical JDBC connection string for Alchemy:

jdbc:api:Profile=C:\profiles\Alchemy.apip;AuthScheme=APIKey;Network=eth-mainnet;ProfileSettings='APIKey=your_api_key';

Create a JRuby App with Connectivity to Alchemy Data

Create a new Ruby file (for example: APISelect.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 Alchemy 2018/lib/cdata.jdbc.api.jar'

url = "jdbc:api:Profile=C:\profiles\Alchemy.apip;AuthScheme=APIKey;Network=eth-mainnet;ProfileSettings='APIKey=your_api_key';"
conn = java.sql.DriverManager.getConnection(url)
stmt = conn.createStatement
rs = stmt.executeQuery("SELECT Address, Name FROM ContractsForOwner")
while (rs.next) do
  puts rs.getString(1) + ' ' + rs.getString(2)
end

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

jruby -S APISelect.rb

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