1. Jennifer Widom Querying XML XSLT

2. Jennifer Widom XSLT Querying XML Not nearly as mature as Querying Relational  Newer  No underlying algebra Sequence of development 1. XPath 2. XSLT 3. XQuery

3. Jennifer Widom XSLT XSL = Extensible Stylesheet Language XSLT = XSL (with) Transformations XSLT

4. Jennifer Widom XSLT as Query Language XSLT Processor XSLT Processor XML Document or Stream XML Document or Stream XML Document or Stream XML Document or Stream XSLT Specification (in XML) XSLT Specification (in XML) Query Processor Query Processor Database Query Answer

5. Jennifer Widom XSLT: Rule-Based Transformations XSLT  Match template and replace  Recursively match templates  Extract values  Iteration (for-each)  Conditionals (if)  Strange default/whitespace behavior  Implicit template priority scheme Demo: XSLT examples over bookstore data Demo: XSLT examples over bookstore data