Sqlserver 取汉字的第一个字母，方便模糊查询

 create function comm_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'
         &nb