[MSSQL]取汉字首字母的两个函数

go
--创建取汉字首字母函数(第一版)
create function [dbo].[f_getpy_V1] (@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) 
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

--创建取汉字首字母函数(第二版)
create function [dbo].[f_getpy_V2](@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 '嘸'
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
--测试示例
select dbo.[f_getpy_V1]('王立国') as V11
select dbo.[f_getpy_V2]('王立国') as V21
select dbo.[f_getpy_V1]('重复') as V21
select dbo.[f_getpy_V2]('重复') as V22
--运行结果
/*
V11
--------
WLG
V21
--------
WLG
V21
--------
ZF
V22
--------
ZF
*/
--由上我们可以看到，两种方法都没有解决多音字的问题。