XML, XSLT, XPath, XQuery 5 Aug 2002

Introduction XML (eXtensible Markup Language) –Holding data XSLT (eXtensible Style Language Transform) –Transform one XML to another XML or other text such as HTML XPath (XML Path) –A way to locate items in a XML file XQuery (XML Query) –Query on one or more XML file to produce another XML file

Analogy XML viewDatabase view XMLData XSLTHTML with ASP,JSP XPathReferring to a field, such as Student.id XQuerySQL RDMS enforced constraintSelf-describing storageExchange and sharing structuredSemi-structured Properties

Sample XML (link)link Mozart Austrian Beethoven German Bach German Mahler Austrian Specify XSL for display

DOM Tree Text Node Element Node Root Node Attribute Node authors author period Classical namenationality period Classical namenationality period Baroque namenationality MozartAustrian GermanBeethovenGermanBach

Sample XSL (link)link Authors Composers from Austria Name XSL version XPath

Output (link)link Original XML Transformed XML

Sample XSL Authors Composers from classical period Name

Output Original XML Transformed XML

P2P Example (link)link

XQuery (link) (xquery)linkxquery { FOR $i IN document(“index.xml")/peer/image WHERE $i/signature > “10” AND $i/signature < “16” RETURN $i } > sample –f index.xml –a index.xml –q query.xqu 15 13

Illustration XML XQueryXML XQuery engine DTD/ schema Validating parser XSL XML/ text/ HTML Browser XPath Assist

Possible Application XML index file P2P Web/ Gnutella gateway XQuery XML Web Other P2P client XQuery Other presentation method