今天碰到了取拼音首字母的需求。整理了一下。
1、编码表：

/*DDL Information For - test.cs_char2letter*/
------------------------------------------------------

Table           Create Table                                
--------------  ---------------------------------------------
cs_char2letter  CREATE TABLE `cs_char2letter` (             
                  `PY` char(1) character set utf8 NOT NULL, 
                  `HZ` char(1) NOT NULL default '',         
                  PRIMARY KEY  (`PY`)                       
                ) ENGINE=InnoDB DEFAULT CHARSET=gbk   
 

2、记录信息：

query result(23 records)

PY	HZ
A	骜
B	簿
C	错
D	�
E	�
F	鳆
G	�
H	�
J	�
K	�
L	�
M	�
N	�
O	沤
P	曝
Q	�
R	�
S	�
T	箨
W	鹜
X	�
Y	韵
Z	�

3、取拼音首字母的函数：
DELIMITER $$

DROP FUNCTION IF EXISTS `test`.`func_get_first_letter`$$

CREATE DEFINER=`root`@`localhost` FUNCTION `func_get_first_letter`(
 words   varchar(255)) RETURNS  char(1) CHARSET utf8
BEGIN  
  declare fpy char(1);  
  declare pc char(1);  
  declare cc char(4);  
  set @fpy = UPPER(left(words,1));  
  set @pc = (CONVERT(@fpy   USING   gbk));  
  set @cc = hex(@pc);  
  if @cc >= "8140" and @cc <="FEA0" then 
    begin  
      select PY from cs_char2letter where hz>= @pc limit 1 into @fpy;
    end;  
  end   if;  
  Return   @fpy;  
  END$$

DELIMITER ;

4、测试结果：

select func_get_first_letter('我是月亮'),func_get_first_letter('月亮是我'),func_get_first_letter('他爸也是我');

query result(1 records)

func_get_first_letter('我是月亮')	func_get_first_letter('月亮是我')	func_get_first_letter('他爸也是我')
W	Y	T

5、附上表插表语句：
truncate table cs_char2letter;
set names utf8;
insert into cs_char2letter values
('A','骜'),
('B','簿'),
('C','错'),
('D','�'),
('E','�'),
('F','鳆'),
('G','�'),
('H','�'),
('J','�'),
('K','�'),
('L','�'),
('M','�'),
('N','�'),
('O','沤'),
('P','曝'),
('Q','�'),
('R','�'),
('S','�'),
('T','箨'),
('W','鹜'),
('X','�'),
('Y','韵'),
('Z','�');