NOTE:
These slides have not been updated since 2003. They have been superseded by the book
Anders Møller and Michael Schwartzbach, February 2006 |
THE XML REVOLUTION - TECHNOLOGIES FOR THE FUTURE WEB |
Example:
<unique name="uniqueness-requirement-87"> <selector xpath=".//personlist"/> <field xpath="person/@ssn"/> </unique> |
occurring in an element declaration, means that: within each personlist, every ssn attribute of a person element must have a unique value.
Similarly, we can define keys (with key) and references (with keyref) which generalizes the ID/IDREF mechanism from DTD in a straightforward way.
Only a simple subset of XPath is allowed:
COPYRIGHT © 2000-2003 ANDERS MØLLER & MICHAEL I. SCHWARTZBACH |