mysql_love_2

create_table_1.rb

create_table :foo, :id => false do |t|
  t.column :id, :manual_pk
  t.column :bytes, :big_integer
end

new_natives.rb

module ActiveRecord
  module ConnectionAdapters
    class MysqlAdapter < AbstractAdapter
      alias :original_native_database_types :native_database_types

      def native_database_types
        original_native_database_types.update(
            :big_integer  => { :name => "bigint", :limit => 21 },
            :manual_pk    => "int(11) NOT NULL PRIMARY KEY")
      end
    end
  end
end

rails.rb

ActiveRecord::ConnectionAdapters::MysqlAdapter.register :big_integer, { :name => "bigint", :limit => 21 }
ActiveRecord::ConnectionAdapters::MysqlAdapter.register :manual_pk, "int(11) NOT NULL PRIMARY KEY"

refactor.rb

create_table :foo, :id => false do |t|
  t.manual_pk :id
  t.big_integer :bytes
end

table_definition.rb

module ActiveRecord
  module ConnectionAdapters
    class TableDefinition
      %w(big_integer manual_pk).each do |column_type|
        class_eval <<-EOV
          def #{column_type}(*args)
            options = args.extract_options!
            column_names = args

            column_names.each { |name| column(name, '#{column_type}', options) }
          end
        EOV
      end
    end
  end
end