n(V(edge-attribute-equality-string,order.@id,=,'1'),P(edge-element-presence-none,=,root:http://www.sleepycat.com/2002/dbxml.order),P(node-element-equality-string,prefix,customer_id)) P(edge-element-presence-none,=,root:http://www.sleepycat.com/2002/dbxml.order) P(node-element-equality-string,prefix,customer_id)