sql 中文转拼音首字母

--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')