Remove ActiveRecord in Rails 3

I’m going by this from reading the source, so let me know if it actually worked. 🙂

The rails command that generates the application template now has an option -O, which tells it to skip ActiveRecord.

If you don’t feel like rerunning rails, you should check the following in your existing app:

• Check that your config/application.rb doesn’t have require 'rails/all' or require "active_record/railtie". Instead, for a standard Rails setup without ActiveRecord, it should have only the following requires:

  require File.expand_path('../boot', __FILE__)
  
  require "action_controller/railtie"
  require "action_mailer/railtie"
  require "active_resource/railtie"
  require "rails/test_unit/railtie"
  require "sprockets/railtie"
  
  # Auto-require default libraries and those for the current Rails environment. 
  Bundler.require :default, Rails.env
  

• If, in config/application.rb, you are using the config.generators section, make sure it doesn’t have the line g.orm :active_record. You can set this explicitly to nil, if you want, but this should be the default when g.orm is completely omitted.

• Optional, but in your Gemfile, remove the gem line that loads the module for your database. This could be the line gem "mysql" for example.