>> ActiveRecord::Base.find_by_sql("show tables")[-1]
=> #<ActiveRecord::Base:0x408209b0 @attributes={"Tables_in_tmk_predictivo"=>"usuarios"}>
>> ActiveRecord::Base.find_by_sql("show tables").class
=> Array
>> ActiveRecord::Base.find_by_sql("show tables")[-1][:Tables_in_tmk_predictivo]
NoMethodError: undefined method `abstract_class?' for Object:Class
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1252:in `class_of_active_record_descendant'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:903:in `base_class'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:565:in `reset_table_name'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:561:in `table_name'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:696:in `columns'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:704:in `columns_hash'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1562:in `column_for_attribute'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1801:in `read_attribute'
        from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1489:in `[]'
        from (irb):64
        from :0