A method for converting relational data to XML (Extensible Markup Language) is provided. The method, sometimes referred to as SilkRoute, provides a general, dynamic and efficient tool for viewing and querying relational data in XML. SilkRoute can express mappings of relational data in XML that conforms to arbitrary public document type definitions. Also, SilkRoute can materialize the fragment of an XML view needed by an application and it can fully exploit the query engine of a relational database management system whenever data items in an XML view need to be materialized.