-- Use FOR XML PATH('Customer')
SELECT
CustomerID as "@CustomerID",
CompanyName,
Address as "address/street",
City as "address/city",
Region as "address/region",
PostalCode as "address/zip",
Country as "address/country",
ContactName as "contact/name",
ContactTitle as "contact/title",
Phone as "contact/phone",
Fax as "contact/fax"
FROM Customers
FOR XML PATH('Customer')
-- will result in
<Customer CustomerID="ALFKI">
<CompanyName>Alfreds Futterkiste</CompanyName>
<address>
<street>Obere Str. 57</street>
<city>Berlin</city>
<zip>12209</zip>
<country>Germany</country>
</address>
<contact>
<name>Maria Anders</name>
<title>Sales Representative</title>
<phone>030-0074321</phone>
<fax>030-0076545</fax>
</contact>
</Customer>