转来的，很好用，要谢谢作者的

Create function [dbo].[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