SQL中文字符转换为拼音首字母的方法与技巧

--可支持大字符集20000个汉字!

create function f_ch2py(@chn nchar(1))
returns char(1)
as
begin
declare @n int
declare @c char(1)
set @n = 63

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‘ union all select  --because have no ‘i‘
‘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‘ union all select  --no ‘u‘
‘屲‘ union all select  --no ‘v‘
‘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
return(@c)
end
go

select dbo.f_ch2py(‘中‘)  --Z
select dbo.f_ch2py(‘国‘)  --G
select dbo.f_ch2py(‘人‘)  --R
select dbo.f_ch2py(‘镆‘)  --M
go
-----------------调用
CREATE FUNCTION F_GetHelpCode (
        @cName VARCHAR(20) )
RETURNS VARCHAR(12)
AS
BEGIN
   DECLARE @i SMALLINT, @L SMALLINT , @cHelpCode VARCHAR(12), @e VARCHAR(12), @iAscii SMALLINT
   SELECT @i=1, @L=0 , @cHelpCode=‘‘
   while @L<=12 AND @i<=LEN(@cName) BEGIN
      SELECT @e=LOWER(SUBSTRING(@cname,@i,1))
      SELECT @iAscii=ASCII(@e)
      IF @iAscii>=48 AND @iAscii <=57 OR @iAscii>=97 AND @iAscii <=122 or @iAscii=95 
       SELECT @cHelpCode=@cHelpCode  +@e
      ELSE
      IF @iAscii>=176 AND @iAscii <=247
            SELECT @cHelpCode=@cHelpCode  + dbo.f_ch2py(@e)
        ELSE SELECT @L=@L-1
      SELECT @i=@i+1, @L=@L+1 END 
    RETURN @cHelpCode
END
GO

--调用
select dbo.F_GetHelpCode(‘大力‘)