SQL Server中全半角转换函数

CREATE FUNCTION F_Convert_CharSet(

@string nvarchar(4000) -- 输入的字符串

,@flag tinyint -- 转换标识(1:全角转半角；其他：半角转全角)

)

RETURNS nvarchar(2000)

WITH ENCRYPTION

AS

BEGIN

DECLARE @i int

,@ret nvarchar(2000)

select @i=1

SET @ret= ' '

if(@flag=1)

begin

while SUBSTRING(@string,@i,1) <> ' '

begin

if UNICODE(SUBSTRING(@string,@i,1))> 255

SET @ret=@ret+NCHAR(UNICODE(SUBSTRING(@string,@i,1))-

CASE

WHEN SUBSTRING(@string,@i,1)= '。 ' THEN 12244 ELSE 65248

END )

else

SET @ret=@ret+(SUBSTRING(@string,@i,1))

SET @i=@i+1

end

end

else

begin

while @i <=len(@string)

begin

if unicode(SUBSTRING(@string, @i, 1)) <256

select @ret = @ret + NCHAR(unicode(SUBSTRING(@string, @i, 1))+ 0xFEE0 )

else

select @ret = @ret + SUBSTRING(@string, @i, 1)

SET @i=@i+1

end

end

return @ret

end