Create single XML from SQL Server multiple tables query

Question

I would like to query multiple tables from SQL Server 2005 and create a single XML document and do this in a stored procedure.

I know that I can query multiple tables within a stored procedure and get a DataSet in my .NET application that can be easily saved as XML. However, I'm trying to do something similar within the context of a stored procedure.

Essentially I want to do something like this:

declare @x xml
select @x = x.result
from (select y.* from tabley y for xml path('y')
      union
      select a.* from tablea a for xml path('aa')
     ) as x
select @x

Answer 1

If you want them just one after the other, you can try something like this:

SELECT
    (SELECT y.* FROM dbo.TableY FOR XML PATH('y'), TYPE) AS 'YElements',
    (SELECT a.* FROM dbo.TableA FOR XML PATH('aa'), TYPE) AS 'AElements'
FOR XML PATH(''), ROOT('root')

That return an XML something like:

<root>
   <YElements>
     <Y>
       ....
     </Y>
     <Y>
       ....
     </Y>
      ......
   </YElements>
   <AElements>
     <A>
       ....
     </A>
     <A>
       ....
     </A>
      ......
   </AElements>
</root>