Simple usage of AR outside of rails

active-record-demo.rb

require 'rubygems'
require 'active_record'
ActiveRecord::Base.establish_connection :adapter => "sqlite3", :database => ":memory:"

ActiveRecord::Schema.define do
  create_table :authors do |t|
    t.string :name, :null => false
  end

  add_index :authors, :name, :unique

  create_table :posts do |t|
    t.integer :author_id, :null => false
    t.string :subject
    t.text :body
    t.boolean :private, :default => false
  end

  add_index :posts, :author_id
end

class Author < ActiveRecord::Base
  has_many :posts
end

class Post < ActiveRecord::Base
end

author = Author.create :name => "Jeremy"
author.posts.build :subject => "A test", :body => "The body"
p author.posts