Building Oracle XML Applications

Acquiring Web-based XML Content

We check out the ServletsFAQ.xml file on Sun’s site, which they update periodically, and notice that it has a format like this:

<?xml version = '1.0' encoding = 'UTF-8'?> 
<Servlets-FAQ>
  <FAQ>
    <Q>What's the next major release of the Servlet API?</Q>
    <A>Servlet API 2.2</A>
  </FAQ>
  <FAQ>
    <Q>How do I set the age of a cookie?</Q>
    <A>yourCookie.setAge(120);</A>
  </FAQ>
  <FAQ>
    <Q>How do I save a variable in a per-user session?</Q>
    <A>request.getSession(true).putValue('varname','value');</A>
  </FAQ>
</Servlets-FAQ>

We want this Servlet FAQ content and others like it from Sun’s site to reside in our database so we can search over it together with all of our own content. We learn that the Oracle XML SQL Utility can insert XML documents automatically into our faq_table if they have the canonical <ROWSET>/<ROW> structure, so we create another XSLT stylesheet to transform a document in Sun’s <Servlets-FAQ> vocabulary into a <ROWSET>/<ROW> document:

<ROWSET xsl:version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:for-each select="/Servlets-FAQ/FAQ">
    <ROW>
      <CATEGORY>SERVLETS</CATEGORY>
      <QLEVEL>1</QLEVEL>
      <QUESTION><xsl:value-of select="Q"/></QUESTION>
      <ANSWER><xsl:value-of select="A"/></ANSWER>
      <SUBMITTED_BY>Sun</SUBMITTED_BY>
    </ROW>
  </xsl:for-each>
</ROWSET>

This time, the tables are turned and our XPath expressions in <xsl:for-each> are looping over Sun’s XML format and constructing the <ROWSET>, <ROW>, and column-name elements required for the automatic ...