Gemfile

source "https://rubygems.org"

gem "activerecord"
gem "sqlite3"

group :development do
  gem "pry"
end

sites.yml

rubyonrails:
  name: Ruby on Rails
  url: http://www.rubyonrails.org

google:
  name: Google
  url: http://www.google.com

sqyaml.rb

require "active_record"
require "active_record/fixtures"

ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")

ActiveRecord::Schema.define(version: 1) do
  create_table :sites do |t|
    t.text :name
    t.text :url
  end
end

class Site < ActiveRecord::Base
end

ActiveRecord::FixtureSet.create_fixtures(__dir__, Dir["*.yml"].map {|file| File.basename(file, ".yml") })

require "pry"
binding.pry