This post originated from an RSS feed registered with Ruby Buzz by Jamis Buck. Original Post: Easy ActiveRecord Scripts Feed Title: the buckblogs here Feed URL: http://weblog.jamisbuck.org/blog.cgi/programming/index.rss Feed Description: Jamis Buck's corner of the blogging universe. Mostly about ruby, but includes ramblings on a variety of topics. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Jamis Buck Latest Posts From the buckblogs here

ActiveRecord (the ORM component of Rails) is really a pretty slick little piece of equipment. Not only does it integrate seamlessly with the other parts of the Rails stack, it can be easily used on its own. I do so frequently when trying to duplicate reported bugs. Consider the following little script:

  require 'active_record'

  ActiveRecord::Base.logger = Logger.new(STDERR)
  ActiveRecord::Base.colorize_logging = false

  ActiveRecord::Base.establish_connection(
    :adapter => "sqlite",
    :dbfile  => ":memory:" 
  )

  ActiveRecord::Schema.define do
    create_table :foxes do |t|
      t.column :name, :string
    end

    create_table :trucks do |t|
      t.column :fox_id, :integer
      t.column :color, :string
    end
  end

  class Fox < ActiveRecord::Base
    has_many :trucks
  end

  class Truck < ActiveRecord::Base
    belongs_to :fox
  end

  fox = Fox.create :name => "Small" 
  fox.trucks.create :color => "Blue" 
  fox.trucks.create :color => "Orange" 

  puts Fox.find(1).trucks.length

The above script uses an in-memory SQLite database, so it doesn’t leave any messes around on disk. It also logs to STDERR, so I can see all the SQL that is produced, and it turns off colorized logging (because I prefer a white-background terminal and AR’s colors aren’t very friendly to that). It then defines the tables using ActiveRecord::Schema, defines the classes, adds some data, and then manipulates the data.

Nice and simple! (Note that ActiveRecord::Schema is only available in the beta gems, currently, but everything else should work with the released version of AR.)