ms sql汉字首字母查询

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[fGetPy]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[fGetPy]
GO

--创建取拼音函数
create function fGetPy(@Str varchar(500)='')
returns varchar(500)
as
begin
declare @strlen int,@return varchar(500),@ii int
declare @n int,@c char(1),@chn nchar(1)

select @strlen=len(@str),@return='',@ii=0
set @ii=0
while @ii<@strlen
begin
select @ii=@ii+1,@n=63,@chn=substring(@str,@ii,1)
if @chn>'z'
select @n = @n +1
,@c = case chn when @chn then char(@n) else @c end
from(
select top 27 * from (
select chn = '吖'
union all select '八'
union all select '嚓'
union all select '咑'
union all select '妸'
union all select '发'
union all select '旮'
union all select '铪'
union all select '丌'  --because have no 'i'
union all select '丌'
union all select '咔'
union all select '垃'
union all select '呒'
union all select '拏'
union all select '噢'
union all select '妑'
union all select '七'
union all select '呥'
union all select '仨'
union all select '他'
union all select '屲'  --no 'u'
union all select '屲'  --no 'v'
union all select '屲'
union all select '夕'
union all select '丫'
union all select '帀'
union all select @chn) as a
order by chn COLLATE Chinese_PRC_CI_AS
) as b
else set @c='a'
set @return=@return+@c
end
return(@return)
end

go

测试语句：
SELECT * from N_Drugs_Info where  dbo.fgetpy(aaa.dbo.N_Drugs_Info.Drugs_CnName) LIKE '%yww%'