HexToINT
An optimized function for converting a HEX string into a INT. Built for being faster then other HexToDec converters.
Slightly slower then HexToSMALLINT.
If there is any faster function to do this conversion, I am intrested of using it instead.
/*
Input has to be a Valid Hexadecimal number. Example 4F or 04F or 004F.
7FFFFFFF is the maximum value and it gives 2147483647 (Max INT)
Hans Lindgren
*/CREATE FUNCTION dbo.HexToINT
(
@Value VARCHAR(8)
)
RETURNS INT
AS
BEGIN
SET @Value = REVERSE( RIGHT( UPPER( '0000000' + @Value ) , 8 ) )
RETURN (
(CHARINDEX( SUBSTRING( @Value , 1 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 ) +
16* (CHARINDEX( SUBSTRING( @Value , 2 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 ) +
256* (CHARINDEX( SUBSTRING( @Value , 3 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 ) +
4096* (CHARINDEX( SUBSTRING( @Value , 4 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 ) +
65536* (CHARINDEX( SUBSTRING( @Value , 5 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 ) +
1048576* (CHARINDEX( SUBSTRING( @Value , 6 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 ) +
16777216* (CHARINDEX( SUBSTRING( @Value , 7 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 ) +
268435456*(CHARINDEX( SUBSTRING( @Value , 8 , 1 ) , '0123456789ABCDEF' , 1 ) - 1 )
)
END
GO
SELECT
dbo.HexToINT('0ABCDEF') ,
dbo.HexToINT('01234567') ,
dbo.HexToINT('0FFF') ,
dbo.HexToINT('0') AS MinValue,
dbo.HexToINT('7FFFFFFF') AS MaxValue 
