Thursday, July 03, 2008

Converting from hex string to varbinary and vice versa

by SQL Server Engine Team via SQL Server Engine Tips on 7/3/2008 4:26:00 AM

Converting hexadecimal values to varbinary and vice versa is now easier using the XQuery functionality available from SQL Server 2005. The code samples below show how to perform the conversion(s):

-- Convert hexstring value in a variable to varbinary:

declare @hexstring varchar(max);

set @hexstring = 'abcedf012439';

select cast('' as xml).value('xs:hexBinary( substring(sql:variable("@hexstring"), sql:column("t.pos")) )', 'varbinary(max)')

from (select case substring(@hexstring, 1, 2) when '0x' then 3 else 0 end) as t(pos)

go

-- Convert binary value in a variable to hexstring:

declare @hexbin varbinary(max);

set @hexbin = 0xabcedf012439;

select '0x' + cast('' as xml).value('xs:hexBinary(sql:variable("@hexbin") )', 'varchar(max)');

go

For more details on XQuery see link below:

http://msdn.microsoft.com/en-us/library/ms189075(SQL.100).aspx

In SQL Server 2008, these conversions are even more easier since we added support directly in the CONVERT built-in function. The code samples below show how to perform the conversion(s):

declare @hexstring varchar(max);

set @hexstring = '0xabcedf012439';

select CONVERT(varbinary(max), @hexstring, 1);

set @hexstring = 'abcedf012439';

select CONVERT(varbinary(max), @hexstring, 2);

go

declare @hexbin varbinary(max);

set @hexbin = 0xabcedf012439;

select CONVERT(varchar(max), @hexbin, 1), CONVERT(varchar(max), @hexbin, 2);

go

For more details on the new CONVERT binary styles see link below:

http://msdn.microsoft.com/en-us/library/ms187928(SQL.100).aspx