php递归实现无限分类原理

DROP TABLE IF EXISTS `navs`;
CREATE TABLE IF NOT EXISTS `navs` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) NOT NULL,
  `pid` int(11) NOT NULL DEFAULT '0',
  `path` char(128) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;
INSERT INTO `navs` (`id`, `name`, `pid`) VALUES
(1, '舞文弄墨', 0, '-1-'),
(2, '似水流年', 2, '-2-'),
(3, '隔岸观火', 2, '-2-3-'),
(4, 'WEB开发', 0, '-4-'),
(5, 'PHP', 4, '-4-5-'),
(6, 'Javascript', 4, '-4-6-');
(7, 'jquery', 6, '-4-6-7-');