SQL Server编写函数获取汉字的拼音码（首字母）

Create function fun_getPY ( @str nvarchar(4000) ) 
returns nvarchar(4000) 
as 
begin 
declare @word nchar(1),@PY nvarchar(4000) 
set @PY='' 
while len(@str)>0 
begin 
set @word=left(@str,1) 
--如果非汉字字符，返回原字符 
set @PY=@PY+(case when unicode(@word) between 19968 and 19968+20901 
then ( 
select top 1 PY 
from 
( 
select 'A' as PY,N'驁' as word 
union all select 'B',N'簿' 
union all select 'C',N'錯' 
union all select 'D',N'鵽' 
union all select 'E',N'樲' 
union all select 'F',N'鰒' 
union all select 'G',N'腂' 
union all select 'H',N'夻' 
union all select 'J',N'攈' 
union all select 'K',N'穒' 
union all select 'L',N'鱳' 
union all select 'M',N'旀' 
union all select 'N',N'桛' 
union all select 'O',N'漚' 
union all select 'P',N'曝' 
union all select 'Q',N'囕' 
union all select 'R',N'鶸' 
union all select 'S',N'蜶' 
union all select 'T',N'籜' 
union all select 'W',N'鶩' 
union all select 'X',N'鑂' 
union all select 'Y',N'韻' 
union all select 'Z',N'咗' 
) T 
where word>=@word collate Chinese_PRC_CS_AS_KS_WS 
order by PY ASC 
) 
else @word 
end) 
set @str=right(@str,len(@str)-1) 
end 
return @PY 
end 

--调用

select dbo.fun_getpy('张三') 

--结果：ZS