sqlserver 根据拼音首字母查询数据

create function f_GetPy(@Str nvarchar(400))
returns nvarchar(4000)
as

begin

declare @strlen int,@re nvarchar(4000)
declare @t table(chr nchar(1) collate Chinese_PRC_CI_AS,letter nchar(1))
insert @t select '吖','A'
union all select '八','B'
union all select '嚓','C'
union all select '咑','D'
union all select '妸','E'
union all select '发','F'
union all select '旮','G'
union all select '铪','H'
union all select '丌','J'
union all select '咔','K'
union all select '垃','L'
union all select '嘸','M'
union all select '拏','N'
union all select '噢','O'
union all select '妑','P'
union all select '七','Q'
union all select '呥','R'
union all select '仨','S'
union all select '他','T'
union all select '屲','W'
union all select '夕','X'
union all select '丫','Y'
union all select '帀','Z'
select @strlen=len(@str),@re=''
while @strlen>0
begin 
select top 1 @re=letter+@re,@strlen=@strlen-1
from @t a where chr<=substring(@str,@strlen,1)
order by chr desc
if @@rowcount=0 
select @re=substring(@str,@strlen,1)+@re,@strlen=@strlen-1
end 
return(@re)
end
go 

select dbo.f_GetPy('北京') as 北京

select * from uUsers where left(dbo.f_GetPy(uName),1)='L'