CREATE TABLE IF NOT EXISTS `category` (
`id` int(6) unsigned NOT NULL,
`orderNum` int(6) NULL,
`name` varchar(200) NOT NULL,
PRIMARY KEY (`id`)
) DEFAULT CHARSET=utf8;
INSERT INTO `category` (`id`, `orderNum`, `name`) VALUES
('1', '17', 'test 4'),
('2', null, 'test 3'),
('3', '35', 'test 6'),
('4', null, 'test 2'),
('5', '22', 'test 1'),
('6', '24', 'test 5');
SELECT * FROM `category`
ORDER BY COALESCE(`orderNum`, `name`)