Learn more about the CData JDBC Driver for JSON or download a free trial:
JRuby はRuby プログラミング言語の高性能で安定した、完全にスレッド化されたJava 実装です。CData JDBC Driver for JSON を使用すると、JRuby からリアルタイムJSON services へのデータ連携を簡単に実装できます。ここでは、JSON services に接続し、クエリを実行して結果を表示する簡単なJRuby アプリを作成する方法を説明します。
Before creating the app, note the installation location for the JAR file for the JDBC Driver (typically C:\Program Files\CDatat\CData JDBC Driver for JSON\lib).
JRuby natively supports JDBC, so you can easily connect to JSON and execute SQL queries.Initialize the JDBC connection with the getConnection function of the java.sql.DriverManager class.
See the Getting Started chapter in the data provider documentation to authenticate to your data source: The data provider models JSON APIs as bidirectional database tables and JSON files as read-only views (local files, files stored on popular cloud services, and FTP servers). The major authentication schemes are supported, including HTTP Basic, Digest, NTLM, OAuth, and FTP. See the Getting Started chapter in the data provider documentation for authentication guides.
After setting the URI and providing any authentication values, set DataModel to more closely match the data representation to the structure of your data.
The DataModel property is the controlling property over how your data is represented into tables and toggles the following basic configurations.
See the Modeling JSON Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.
For assistance in constructing the JDBC URL, use the connection string designer built into the JSON JDBC Driver.Either double-click the JAR file or execute the jar file from the command-line.
java -jar cdata.jdbc.json.jar
Fill in the connection properties and copy the connection string to the clipboard.
Below is a typical JDBC connection string for JSON:
jdbc:json:URI=C:\people.json;DataModel=Relational;
Create a new Ruby file (for example: JSONSelect.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 JSON 2018/lib/cdata.jdbc.json.jar'
url = "jdbc:json:URI=C:\people.json;DataModel=Relational;"
conn = java.sql.DriverManager.getConnection(url)
stmt = conn.createStatement
rs = stmt.executeQuery("SELECT [ personal.name.first ], [ personal.name.last ] FROM people")
while (rs.next) do
puts rs.getString(1) + ' ' + rs.getString(2)
end
With the file completed, you are ready to display your JSON services with JRuby.To do so, simply run your file from the command line:
jruby -S JSONSelect.rb
Writing SQL-92 queries to JSON allows you to quickly and easily incorporate JSON services into your own JRuby applications.Download a free trial today!