求助，如何使用mysql实现得到汉字的首字母

Question

表table:
id hanzi
1  东
2  西
3  南
4  北
5  中执行函数后得到table为
id hanzi
1  d
2  x
3  n
4  b
5  z

Answer 1

我在网上搜了一些方法，如下DROP   TABLE   IF   EXISTS   `pyk`;   
  CREATE   TABLE   `pyk`   (   
      `PY`   varchar(1)    ,   
      `HZ1`   int  ,
      `HZ2`   int      
  ) ;
   
INSERT   INTO   `pyk`   (`PY`,`HZ1`,`HZ2`)   VALUES     
('A',-20319,-20284),
('B',-20283,-19776),
('C',-19775,-19219),
('D',-19218,-18711),
('E',-18710,-18527),
('F',-18526,-18240),
('G',-18239,-17923),
('I',-17922,-17418),              
('J',-17417,-16475),              
('K',-16474,-16213),              
('L',-16212,-15641),              
('M',-15640,-15166),              
('N',-15165,-14923),              
('O',-14922,-14915),              
('P',-14914,-14631),              
('Q',-14630,-14150),              
('R',-14149,-14091),              
('S',-14090,-13319),              
('V',-13318,-12839),              
('W',-12838,-12557),              
('X',-12556,-11848),              
('Y',-11847,-11056),              
('Z',-11055,-10247);
DROP FUNCTION IF EXISTS hzcode;delimiter //CREATE FUNCTION hzcode (s CHAR(255)) RETURNS char
BEGIN
DECLARE hz_code int;
DECLARE hz_py char;
SET hz_code = ord(substring(s,1,1))*256+ord(substring(s,2,1))-65536 ;
select py into hz_py from pyk where  hz_code>=pyk.hz1 and hz_code<=pyk
.hz2;                  
RETURN hz_py;
END
//delimiter ;

Answer 2

但是在执行到SET hz_code = ord(substring(s,1,1))*256+ord(substring(s,2,1))-65536 ;
select py into hz_py from pyk where  hz_code>=pyk.hz1 and hz_code<=pyk
.hz2;时，总是得不到应有的hz_code,比如执行select ord(substring('火',1,1))*256+ord(substring('火',2,1))-65536
得到的值是3883969280，根本不在取值范围中

Answer 3

http://topic.csdn.net/u/20090611/17/7579bb9a-0a7c-4460-a302-10bae7f4a9c5.html
mysql 根据英文首字母来查询汉字函数 [推荐]