Prepare a (nested) table of contents for Book1, listing all the sections and their titles. Preserve the original attributes of each <section> element, if any.

Solution in XQuery:

declare function local:toc($book-or-section as element()) as element()*
{
    for $section in $book-or-section/section
    return
      <section>
         { $section/@* , $section/title , local:toc($section) }                 
      </section>
};

<toc>
   {
     for $s in doc("book.xml")/book return local:toc($s)
   }
</toc> 

Expected Result:

<toc>
    <section id="intro" difficulty="easy">
        <title>Introduction</title>
        <section>
            <title>Audience</title>
        </section>
        <section>
            <title>Web Data and the Two Cultures</title>
        </section>
    </section>
    <section id="syntax" difficulty="medium">
        <title>A Syntax For Data</title>
        <section>
            <title>Base Types</title>
        </section>
        <section>
            <title>Representing Relational Databases</title>
        </section>
        <section>
            <title>Representing Object Databases</title>
        </section>
    </section>
</toc> 



Prepare a (flat) figure list for Book1, listing all the figures and their titles. Preserve the original attributes of each <figure> element, if any.

Solution in XQuery:

<figlist>
  {
    for $f in doc("book.xml")//figure
    return
        <figure>
            { $f/@* }
            { $f/title }
        </figure>
  }
</figlist> 

Expected Result:

<figlist>
    <figure  height="400" width="400">
        <title>Traditional client/server architecture</title>
    </figure>
    <figure  height="200" width="500">
        <title>Graph representations of structures</title>
    </figure>
    <figure  height="250" width ="400">
        <title>Examples of Relations</title>
    </figure>
</figlist> 



How many sections are in Book1, and how many figures?

Solution in XQuery:

<section_count>{ count(doc("book.xml")//section) }</section_count>, 
<figure_count>{ count(doc("book.xml")//figure) }</figure_count> 

Expected Result:

<section_count>7</section_count>
<figure_count>3</figure_count> 




How many top-level sections are in Book1?

Solution in XQuery:

<top_section_count>
 { 
   count(doc("book.xml")/book/section) 
 }
</top_section_count>

Expected Result:

<top_section_count>2</top_section_count> 



Make a flat list of the section elements in Book1. In place of its original attributes, each section element should have two attributes, containing the title of the section and the number of figures immediately contained in the section.

Solution in XQuery:

<section_list>
  {
    for $s in doc("book.xml")//section
    let $f := $s/figure
    return
        <section title="{ $s/title/text() }" figcount="{ count($f) }"/>
  }
</section_list> 

Expected Result:

<section_list>
    <section title="Introduction" figcount="0"/>
    <section title="Audience" figcount="0"/>
    <section title="Web Data and the Two Cultures" figcount="1"/>
    <section title="A Syntax For Data" figcount="1"/>
    <section title="Base Types" figcount="0"/>
    <section title="Representing Relational Databases" figcount="1"/>
    <section title="Representing Object Databases" figcount="0"/>
</section_list>



Make a nested list of the section elements in Book1, preserving their original attributes and hierarchy. Inside each section element, include the title of the section and an element that includes the number of figures immediately contained in the section.

Solution in XQuery:

declare function local:section-summary($book-or-section as element())
  as element()*
{
  for $section in $book-or-section
  return
    <section>
       { $section/@* }
       { $section/title }       
       <figcount>         
         { count($section/figure) }
       </figcount>                
       { local:section-summary($section/section) }                      
    </section>
};

<toc>
  {
    for $s in doc("book.xml")/book/section
    return local:section-summary($s)
  }
</toc> 

Editorial note   
This solution was provided by Michael Wenger, a student at the University of Würzburg. 

Expected Result:

<toc>
    <section id="intro" difficulty="easy">
        <title>Introduction</title>
        <figcount>0</figcount>
        <section>
            <title>Audience</title>
            <figcount>0</figcount>
        </section>
        <section>
            <title>Web Data and the Two Cultures</title>
            <figcount>1</figcount>
        </section>
    </section>
    <section id="syntax" difficulty="medium">
        <title>A Syntax For Data</title>
        <figcount>1</figcount>
        <section>
            <title>Base Types</title>
            <figcount>0</figcount>
        </section>
        <section>
            <title>Representing Relational Databases</title>
            <figcount>1</figcount>
        </section>
        <section>
            <title>Representing Object Databases</title>
            <figcount>0</figcount>
        </section>
    </section>
</toc>