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Build a Ruby application

Attention

This page documents an earlier version. Go to the latest (v2.3) version.

Install the pg driver gem

Install the Ruby PostgreSQL driver (pg) using the following command. You can get further details for the driver here.

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

Working example

Prerequisites

This tutorial assumes that you have:

installed YugabyteDB and created a universe with YSQL enabled. If not, please follow these steps in the Quick Start guide.

Writing the Ruby code

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: 'postgres', user: 'postgres', password: 'postgres')

  # 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

Running the application

To run the application, type the following:

$ ./yb-sql-helloworld.rb

You should see the following output.

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