sqlServer 获取汉字字串的拼音声母

CREATE function fGetPy(@str varchar(500)='')
returns varchar(500)
as
begin
declare @strlen int,@return varchar(500),@ii int
declare @c nchar(1),@chn nchar(1)
select @strlen=len(@str),@return='',@ii=0
set @ii=0
while @ii<@strlen
begin
select @ii=@ii+1,@chn=substring(@str,@ii,1)
if @chn>='吖'
select @c = char(count(*)+63) from (
select top 27 * from (
select chn = '吖'
union all select '八'
union all select '嚓'
union all select '??'
union all select '??'
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 '?`'
union all select '??'
union all select '噢'
union all select '?r'
union all select '七'
union all select '??'
union all select '仨'
union all select '他'
union all select '??' --no 'u'
union all select '??' --no 'v'
union all select '??'
union all select '夕'
union all select '丫'
union all select '??'
union all select @chn
) as a
order by chn COLLATE Chinese_PRC_CI_AS ) as b
where b.chn <=@chn
else set @c=@chn
set @return=@return+@c
end
return(@return)
end