按拼音首字母查询（mssql）

1. 先创建function

create function   f_GetPy(@str   nvarchar(4000)) 
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   into   @t(chr,letter) 
    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 

2. 通过调用该function即可. 
select dbo.f_GetPy('我')---->W

select dbo.f_GetPy('你')---->N