十进制/十八进制的互转换(此方法应用于所有进制与10进制的转换)

-- ----十进制转换为十八进制
create function F_int18( @num int )
returns nvarchar ( 50 )
as
begin
if @num = 0
return ' 0 '
declare @s nvarchar ( 50 )
set @s = ''
while @num > 0
select @s = substring ( ' 0123456789ABCDEFHG ' , @num % 18 + 1 , 1 ) + @s , @num = @num / 18
return @s
end

go
-- --------十八进制转换为十进制
create function F_int10( @s nvarchar ( 50 ))
returns int
as
begin
declare @i int , @s2 nvarchar ( 2 ), @num int
select @i = len ( @s ), @num = 0
while @i > 0
select @s2 = substring ( reverse ( @s ), @i , 1 ),
@num = power ( 18 , @i - 1 ) * ( charindex ( @s2 , ' 0123456789ABCDEFHG ' ) - 1 ) + @num ,
@i = @i - 1
return @num
end
go


select dbo.F_int18( 9999 )
select dbo.F_int10( ' 1CF9 ' )

/**/ /*
--------------------------------------------------
1CF9

（所影响的行数为1行）


-----------
9999

（所影响的行数为1行）

*/