Peter DeBetta's blog about programming in SQL Server using technologies such as T-SQL, .NET, CLR, C#, VB, Visual Studio, and SQL Server Management Studio.
[EDIT] I made a few changes to account for the issues Chris and Cooter noted in the comments.
One last post before I go on vacation next week...
SQL Server 2005 includes an undocumented function, sys.fn_varbintohexstr, that converts a hex value to a string representation of that hex value (0x3a becomes '0x3a'), but there is no function to go back from a hex string to a hex value. Now there is J:
CREATE FUNCTION dbo.HexStrToVarBin(@hexstr VARCHAR(8000))
DECLARE @hex CHAR(2), @i INT, @count INT, @b varbinary(8000), @odd BIT, @start bit
SET @count = LEN(@hexstr)
SET @start = 1
SET @b = CAST('' AS varbinary(1))
IF SUBSTRING(@hexstr, 1, 2) = '0x'
SET @i = 3
SET @i = 1
SET @odd = CAST(LEN(SUBSTRING(@hexstr, @i, LEN(@hexstr))) % 2 AS BIT)
WHILE (@i <= @count)
IF @start = 1 AND @odd = 1
SET @hex = '0' + SUBSTRING(@hexstr, @i, 1)
SET @hex = SUBSTRING(@hexstr, @i, 2)
SET @b = @b +
CAST(CASE WHEN SUBSTRING(@hex, 1, 1) LIKE '[0-9]'
THEN CAST(SUBSTRING(@hex, 1, 1) AS INT)
ELSE CAST(ASCII(UPPER(SUBSTRING(@hex, 1, 1)))-55 AS INT)
END * 16 +
CASE WHEN SUBSTRING(@hex, 2, 1) LIKE '[0-9]'
THEN CAST(SUBSTRING(@hex, 2, 1) AS INT)
ELSE CAST(ASCII(UPPER(SUBSTRING(@hex, 2, 1)))-55 AS INT)
END AS binary(1))
SET @i = @i + (2 - (CAST(@start AS INT) * CAST(@odd AS INT)))
IF @start = 1
SET @start = 0
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About Peter W. DeBetta
Peter DeBetta works for Microsoft as an Application Platform Technology Strategist, specializing in strategies, design, implementation, and deployment of Microsoft SQL Server and .NET solutions. Peter writes courseware, articles, and books – most recently the title Introducing SQL Server 2008 from Microsoft Press. Peter speaks at conferences around the world, including TechEd, SQL PASS Community Summit, DevTeach, SQL Connections, DevWeek, and VSLive!
When Peter isn’t working, you can find him singing and playing guitar (click here
to hear an original song by Peter), taking pictures, or simply enjoying life with his wife, son, and daughter.