sql中怎么根据汉字的拼音首字母查询

--可用，速度可以
if   exists   (select   *   from   dbo.sysobjects   where   id   =   object_id(N'[dbo].[fGetPy]')   and   xtype   in   (N'FN',   N'IF',   N'TF'))   
   drop   function   [dbo].[fGetPy]   
   GO   
     
   --创建取拼音函数  
   create   function   fGetPy(@Str   varchar(500)='')   
   returns   varchar(500)   
   as   
   begin   
   declare   @strlen   int,@return   varchar(500),@ii   int   
   declare   @n   int,@c   char(1),@chn   nchar(1)   
     
   select   @strlen=len(@str),@return='',@ii=0   
   set   @ii=0   
   while   @ii <@strlen   
   begin   
   select   @ii=@ii+1,@n=63,@chn=substring(@str,@ii,1)   
   if   @chn>'z'   
   select   @n   =   @n   +1   
   ,@c   =   case   chn   when   @chn   then   char(@n)   else   @c   end   
   from(   
   select   top   27   *   from   (   
   select   chn   =   '吖'   
   union   all   select   '八'   
   union   all   select   '嚓'   
   union   all   select   '咑'   
   union   all   select   '妸'   
   union   all   select   '发'   
   union   all   select   '旮'   
   union   all   select   '铪'   
   union   all   select   '丌' --because   have   no   'i'   
   union   all   select   '丌'   
   union   all   select   '咔'   
   union   all   select   '垃'   
   union   all   select   '嘸'   
   union   all   select   '拏'   
   union   all   select   '噢'   
   union   all   select   '妑'   
   union   all   select   '七'   
   union   all   select   '呥'   
   union   all   select   '仨'   
   union   all   select   '他'   
   union   all   select   '屲' --no   'u'   
   union   all   select   '屲' --no   'v'   
   union   all   select   '屲'   
   union   all   select   '夕'   
   union   all   select   '丫'   
   union   all   select   '帀'   
   union   all   select   @chn)   as   a   
   order   by   chn   COLLATE   Chinese_PRC_CI_AS     
   )   as   b   
   else   set   @c='a'   
   set   @return=@return+@c   
   end   
   return(@return)   
   end   
     
   go  
--测试 
select * from dbo.T_CITY_INFO where dbo.fGetPy(cy_name)='sh'

速度太慢
--2. 汉字首字母查询处理用户定义函数
CREATE FUNCTION f_GetPY(@str nvarchar(4000))
RETURNS nvarchar(4000)
AS
BEGIN
    DECLARE @py TABLE(
        ch char(1),
        hz1 nchar(1) COLLATE Chinese_PRC_CS_AS_KS_WS,
        hz2 nchar(1) COLLATE Chinese_PRC_CS_AS_KS_WS)
    INSERT @py SELECT 'A',N'吖',N'鏊'
    UNION  ALL SELECT 'B',N'八',N'簿'
    UNION  ALL SELECT 'C',N'嚓',N'错'
    UNION  ALL SELECT 'D',N'哒',N'跺'
    UNION  ALL SELECT 'E',N'屙',N'贰'
    UNION  ALL SELECT 'F',N'发',N'馥'
    UNION  ALL SELECT 'G',N'旮',N'过'
    UNION  ALL SELECT 'H',N'铪',N'蠖'
    UNION  ALL SELECT 'J',N'丌',N'竣'
    UNION  ALL SELECT 'K',N'咔',N'廓'
    UNION  ALL SELECT 'L',N'垃',N'雒'
    UNION  ALL SELECT 'M',N'妈',N'穆'
    UNION  ALL SELECT 'N',N'拿',N'糯'
    UNION  ALL SELECT 'O',N'噢',N'沤'
    UNION  ALL SELECT 'P',N'趴',N'曝'
    UNION  ALL SELECT 'Q',N'七',N'群'
    UNION  ALL SELECT 'R',N'蚺',N'箬'
    UNION  ALL SELECT 'S',N'仨',N'锁'
    UNION  ALL SELECT 'T',N'他',N'箨'
    UNION  ALL SELECT 'W',N'哇',N'鋈'
    UNION  ALL SELECT 'X',N'夕',N'蕈'
    UNION  ALL SELECT 'Y',N'丫',N'蕴'
    UNION  ALL SELECT 'Z',N'匝',N'做'
    DECLARE @i int
    SET @i=PATINDEX('%[吖-做]%' COLLATE Chinese_PRC_CS_AS_KS_WS,@str)
    WHILE @i>0
        SELECT @str=REPLACE(@str,SUBSTRING(@str,@i,1),ch)
            ,@i=PATINDEX('%[吖-做]%' COLLATE Chinese_PRC_CS_AS_KS_WS,@str)
        FROM @py
        WHERE SUBSTRING(@str,@i,1) BETWEEN hz1 AND hz2
    RETURN(@str)
END
GO