mysql 取名字首字母的存储过程

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