十六进制转十进制

来源：互联网发布：linux启动tftp服务编辑：程序博客网时间：2024/04/28 04:24

CREATE FUNCTION FN_HEXTOBINARY (@HEX VARCHAR(8))
RETURNS VARCHAR(255)
AS

    BEGIN
     DECLARE @BASE TINYINT
     DECLARE @string VARCHAR(255)
     DECLARE @return VARCHAR(255)
     DECLARE @div INT
     DECLARE @char CHAR(1)
     DECLARE @pos INT
     DECLARE @digit INT
     DECLARE @result varchar(16)
     SELECT @string= '0123456789ABCDEF'
     SELECT @pos = 1
     SELECT @result= ''
     SELECT @return= ''
    SELECT @base=2

    WHILE (@pos<>len(@hex)+1)
    BEGIN
    IF substring(@hex,@pos,1) NOT in ('0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F')
    BEGIN
      RETURN NULL
    END
    SELECT @digit=charindex(substring(@hex,@pos,1),@string)-1
      WHILE (@digit<>0)
      BEGIN
       SELECT @div=@digit/@base
       SELECT @result=convert(varchar(1),(@digit % @base)) + @result
       SELECT @digit=@div
      END
      SELECT @return=@return + CASE WHEN len(@result)<4 THEN replace(space(4-len(@result)) + @result,' ','0') ELSE @result END
      SELECT @result=''
      SELECT @pos=@pos+1
    END
    RETURN @return
END