可能效率很低,但不需要用户定义的函数:
SELECT GROUP_CONCAT(LETTER SEPARATOR '') AS ReOrderedLetters
FROM ( SELECT 'A' as LETTER FROM <table> WHERE UPPER(`name`) like '%A%'
UNION ALL
SELECT 'B' as LETTER FROM <table> WHERE UPPER(`name`) like '%B%'
UNION ALL
SELECT 'C' as LETTER FROM <table> WHERE UPPER(`name`) like '%C%'
UNION ALL
SELECT 'D' as LETTER FROM <table> WHERE UPPER(`name`) like '%D%'
...
UNION ALL
SELECT 'Y' as LETTER FROM <table> WHERE UPPER(`name`) like '%Y%'
UNION ALL
SELECT 'Z' as LETTER FROM <table> WHERE UPPER(`name`) like '%Z%'
) alpha
EDIT
睡觉前我必须想出一个更好的选择,否则我永远睡不着;所以这里有一个更干净、更有效的替代方案。
我创建了一个名为 letter 的表,其中包含一个名为 letter 的 VARCHAR(1) 列;
然后用字母 A 到 Z 填充该表
CREATE TABLE IF NOT EXISTS `letters` (
`letter` varchar(1) NOT NULL,
PRIMARY KEY (`letter`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `letters` (`letter`) VALUES
('A'),('B'),('C'),('D'),('E'),('F'),('G'),('H'),('I'),('J'),('K'),('L'),('M'),
('N'),('O'),('P'),('Q'),('R'),('S'),('T'),('U'),('V'),('W'),('X'),('Y'),('Z');
then:
select U.`name`,
GROUP_CONCAT(L.`letter`
ORDER BY L.`letter` ASC
SEPARATOR '') AS ReOrderedLetters
FROM `users` U
LEFT JOIN `letters` L ON POSITION(L.`letter` IN UPPER(U.`name`)) > 0
GROUP BY U.`name`