Problema con un el orden de un while

[abimaelrc]

Trata así

Código MySQL:

DROP TABLE IF EXISTS `foo`;
CREATE TABLE IF NOT EXISTS `foo` (
  `ID` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `bar` varchar(10) NOT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=16 ;
 
INSERT INTO `foo` (`ID`, `bar`) VALUES
(1, '1'),
(2, '2'),
(3, '3-4'),
(4, '5'),
(5, '6'),
(6, '7'),
(7, '8'),
(8, '9'),
(9, '10'),
(10, '11-12'),
(11, '13'),
(12, '14'),
(13, '15-17'),
(14, '18'),
(15, '19');
 
SELECT * FROM `foo` ORDER BY cast(`bar` AS SIGNED);