ar_model_without_tables.rb

class MyModel < ActiveRecord::Base

  def self.columns
    @columns ||= []
  end

  def self.column(name, sql_type = nil, default = nil, null = true)
    columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, default,
      sql_type.to_s, null)
  end

  # Override the save method to prevent exceptions.
  def save(validate = true)
    validate ? valid? : true
  end


  attr_accessor :a, :b # etc...

end