Learn more about the CData JDBC Driver for PostgreSQL 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 PostgreSQL を使用すると、JRuby からリアルタイムPostgreSQL data へのデータ連携を簡単に実装できます。ここでは、PostgreSQL data 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 PostgreSQL\lib).
JRuby natively supports JDBC, so you can easily connect to PostgreSQL and execute SQL queries.Initialize the JDBC connection with the getConnection function of the java.sql.DriverManager class.
To connect to PostgreSQL, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you wish to use to authenticate to the server. If the Database property is not specified, the data provider connects to the user's default database.
For assistance in constructing the JDBC URL, use the connection string designer built into the PostgreSQL JDBC Driver.Either double-click the JAR file or execute the jar file from the command-line.
java -jar cdata.jdbc.postgresql.jar
Fill in the connection properties and copy the connection string to the clipboard.
Below is a typical JDBC connection string for PostgreSQL:
jdbc:postgresql:User=postgres;Password=admin;Database=postgres;Server=127.0.0.1;Port=5432
Create a new Ruby file (for example: PostgreSQLSelect.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 PostgreSQL 2018/lib/cdata.jdbc.postgresql.jar'
url = "jdbc:postgresql:User=postgres;Password=admin;Database=postgres;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 PostgreSQL data with JRuby.To do so, simply run your file from the command line:
jruby -S PostgreSQLSelect.rb
Writing SQL-92 queries to PostgreSQL allows you to quickly and easily incorporate PostgreSQL data into your own JRuby applications.Download a free trial today!