En version som använder en temporär tabell för att lägga till attributen till XML.
select OrderID,
OrderCode,
DateShipped,
ShipmentXML
into #Order
from [Order]
update #Order
set ShipmentXML.modify
('insert attribute DateShipped {sql:column("DateShipped")}
into (/Order/Item)[1]')
update O
set ShipmentXML.modify
('insert attribute TrackingNumber {sql:column("T.TrackingNumber")}
into (/Order/Item)[1]')
from #Order as O
inner join Tracking as T
on O.OrderCode = T.OrderCode
select OrderID,
OrderCode,
ShipmentXML
from #Order
drop table #Order