Connect an application

This page documents a preview version. v2.23 Preview
Preview includes features under active development and is for development and testing only.
For production, use the latest stable version (v2024.1).

Prerequisites

Install the Ruby PostgreSQL driver (pg) using the following command:

$ gem install pg -- --with-pg-config=<yugabyte-install-dir>/postgres/bin/pg_config

For more information on the driver, see the pg driver documentation.

Create the application

Create a file yb-sql-helloworld.rb and add the following content to it.

#!/usr/bin/env ruby

require 'pg'

begin
  # Output a table of current connections to the DB
  conn = PG.connect(host: '127.0.0.1', port: '5433', dbname: 'yugabyte', user: 'yugabyte', password: 'yugabyte')

  # Create table
  conn.exec ("CREATE TABLE employee (id int PRIMARY KEY, \
                                     name varchar, age int, \
                                     language varchar)");

  puts "Created table employee\n";

  # Insert a row
  conn.exec ("INSERT INTO employee (id, name, age, language) \
                            VALUES (1, 'John', 35, 'Ruby')");
  puts "Inserted data (1, 'John', 35, 'Ruby')\n";

  # Query the row
  rs = conn.exec ("SELECT name, age, language FROM employee WHERE id = 1");
  rs.each do |row|
    puts "Query returned: %s %s %s" % [ row['name'], row['age'], row['language'] ]
  end

rescue PG::Error => e
  puts e.message
ensure
  rs.clear if rs
  conn.close if conn
end

Run the application

To use the application, run the following command:

$ ./yb-sql-helloworld.rb

You should see the following output.

Created table employee
Inserted data (1, 'John', 35, 'Ruby')
Query returned: John 35 Ruby

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