Poor man's magic models

magic.rb

require 'active_record'

class ActiveRecord::Base
  def self.magic!
    connection.tables.map { |table|
      klass = Class.new(self)
      Object.send(:const_set, table.singularize.camelize, klass)
    }.each { |model|
      model.column_names.grep(/_id$/).each { |foreign_key|
        name = foreign_key.sub(/_id$/, '')
        model.belongs_to(name)
        name.camelize.constantize.has_many(model.name.tableize)
      }
    }
  end
end

ActiveRecord::Base.establish_connection(:adapter => 'sqlite3', :database => ':memory:')

ActiveRecord::Schema.define do
  create_table "managers" do |t|
    t.string "name"
  end
  create_table "employees" do |t|
    t.string "name"
    t.belongs_to "manager"
  end
end

ActiveRecord::Base.magic!

mislav = Manager.create :name => "Mislav"
mislav.employees.create(:name => "Josh")
mislav.employees.create(:name => "Mike")

p Manager.first.employees.count
p Employee.first.manager