add_delete.rb

# http://gist.github.com/343293
# it's for rails 1.2.5 
# add require 'add_delete.rb' in environment.rb

class ActiveRecord::Base

  def delete!
    unless new_record?

      affected_rows = connection.delete(
        "DELETE FROM #{self.class.quoted_table_name} " +
        "WHERE #{connection.quote_column_name(self.class.primary_key)} = #{quoted_id} ",
        "#{self.class.name} Destroy"
      )

      unless affected_rows == 1
        raise ActiveRecord::StaleObjectError, "Attempted to delete a stale object"
      end
    end
  end

end