<!--
 -  
 -  This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
 -  project.
 -  
 -  Copyright (C) 1998-2012 OpenLink Software
 -  
 -  This project is free software; you can redistribute it and/or modify it
 -  under the terms of the GNU General Public License as published by the
 -  Free Software Foundation; only version 2 of the License, dated June 1991.
 -  
 -  This program is distributed in the hope that it will be useful, but
 -  WITHOUT ANY WARRANTY; without even the implied warranty of
 -  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 -  General Public License for more details.
 -  
 -  You should have received a copy of the GNU General Public License along
 -  with this program; if not, write to the Free Software Foundation, Inc.,
 -  51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 -  
 -  
-->
<Sales xmlns:sql="urn:schemas-openlink-com:xml-sql">
    <sql:sqlx><![CDATA[  
	select  XMLELEMENT ('Month', 
             XMLATTRIBUTES (sub.year as "year", sub.month as "month"),
                (select XMLAGG (        
                         XMLELEMENT ('Category', XMLATTRIBUTES (sub2.CategoryName), XMLELEMENT ('Sales', sub2.volume)) 
                       )
                      from 
                        (select
                         cat.CategoryName as CategoryName, 
                         sum (od.Quantity*od.UnitPrice*(1-od.Discount)) as volume 
                         from Demo.demo.Orders o1, Demo.demo.Order_Details od, Demo.demo.Products p, Demo.demo.Categories cat 
                         where od.OrderID = o1.OrderID and od.ProductID = p.ProductID and cat.CategoryID = p.CategoryID 
                         and year(o1.OrderDate) = sub.year and month(o1.OrderDate) = sub.month
                         group by 1 
                        ) sub2
                   )
          )
        as result from 
        (select distinct year(o.OrderDate) as year, 
                month(o.OrderDate) as month from Demo.demo.Orders o) sub
	]]></sql:sqlx>
</Sales>
