create function fun_getPY(@str nvarchar(4000)) returns nvarchar(4000)
as
begin
    declare @word nchar(1)
    declare @PY nvarchar(4000)
    set @PY=''
    WHILE len(@str)>0
    begin
        set @word=left(@str,1)
        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
go
select dbo.fun_getPY('dddd)
drop function fun_getPY