做过笔记，好记性不如烂笔头：
1 if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[HEXTOINT]') and xtype in (N'FN', N'IF', N'TF')) 2 drop function [dbo].[HEXTOINT] 3 GO 4 5 SET QUOTED_IDENTIFIER ON 6 GO 7 SET ANSI_NULLS ON 8 GO 9 10 11 12 CREATE function HEXTOINT(@hexstr varchar(10)) 13 returns bigint 14 as 15 begin 16 if left(@hexstr,2) in ('0x','0X') set @hexstr=substring(@hexstr,3,10) 17 declare @i int, @res bigint, @l int, @c char, @ascii0 int, @asciiF int 18 select @i=1, @l=len(@hexstr), @res=0, @ascii0=ascii('0'), @asciiF=ascii('F') 19 if @hexstr is null OR @l=0 return null 20 while @i<=@l begin 21 set @c=upper(substring(@hexstr,@i,1)) 22 if not ascii(@c) between @ascii0 and @asciiF return(null) 23 set @res=@res+cast(1.0 as bigint)*case when isnumeric(@c)=1 then 24 cast(@c as int) else ascii(@c)-55 end*power(16,@l-@i) 25 set @i=@i+1 26 end 27 return(@res) 28 end 29 30 31 32 33 GO 34 SET QUOTED_IDENTIFIER OFF 35 GO 36 SET ANSI_NULLS ON 37 GO
