DECLARE @myDoc xml
DECLARE @AppName VARCHAR(100)
SET @myDoc = '<assembly xmlns="urn:schemas-microsoft-com:asm.v1">
			  <assemblyidentity version="2.2.2.2" Appname="Application2.app">			  
			</assemblyidentity></assembly>'
			
SET @AppName =  @myDoc.value('(/assembly/assemblyidentity/@Appname)[1]', 'char(150)' )
SELECT @AppName

SET @AppName =  @myDoc.value('declare default element namespace "urn:schemas-microsoft-com:asm.v1";
    (/assembly/assemblyidentity/@Appname)[1]', 'char(150)' )
SELECT @AppName