List books published by Addison-Wesley after 1991, including their year and title.

Solution in XQuery:

<bib>
 {
  for $b in doc("http://bstore1.example.com/bib.xml")/bib/book
  where $b/publisher = "Addison-Wesley" and $b/@year > 1991
  return
    <book year="{ $b/@year }">
     { $b/title }
    </book>
 }
</bib> 

Expected Result:

<bib>
    <book year="1994">
        <title>TCP/IP Illustrated</title>
    </book>
    <book year="1992">
        <title>Advanced Programming in the Unix environment</title>
    </book>
</bib>



Create a flat list of all the title-author pairs, with each pair enclosed in a "result" element.

Solution in XQuery:

<results>
  {
    for $b in doc("http://bstore1.example.com/bib.xml")/bib/book,
        $t in $b/title,
        $a in $b/author
    return
        <result>
            { $t }    
            { $a }
        </result>
  }
</results>

Expected Result:

<results>
    <result>
        <title>TCP/IP Illustrated</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </result>
    <result>
        <title>Advanced Programming in the Unix environment</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </result>
    <result>
        <title>Data on the Web</title>
        <author>
            <last>Abiteboul</last>
            <first>Serge</first>
        </author>
    </result>
    <result>
        <title>Data on the Web</title>
        <author>
            <last>Buneman</last>
            <first>Peter</first>
        </author>
    </result>
    <result>
        <title>Data on the Web</title>
        <author>
            <last>Suciu</last>
            <first>Dan</first>
        </author>
    </result>
</results>




For each book in the bibliography, list the title and authors, grouped inside a "result" element.

Solution in XQuery:

<results>
{
    for $b in doc("http://bstore1.example.com/bib.xml")/bib/book
    return
        <result>
            { $b/title }
            { $b/author  }
        </result>
}
</results> 

Expected Result:

<results>
    <result>
        <title>TCP/IP Illustrated</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </result>
    <result>
        <title>Advanced Programming in the Unix environment</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </result>
    <result>
        <title>Data on the Web</title>
        <author>
            <last>Abiteboul</last>
            <first>Serge</first>
        </author>
        <author>
            <last>Buneman</last>
            <first>Peter</first>
        </author>
        <author>
            <last>Suciu</last>
            <first>Dan</first>
        </author>
    </result>
    <result>
        <title>The Economics of Technology and Content for Digital TV</title>
    </result>
</results>



For each author in the bibliography, list the author's name and the titles of all books by that author, grouped inside a "result" element.

Solution in XQuery:

<results>
  {
    let $a := doc("http://bstore1.example.com/bib/bib.xml")//author
    for $last in distinct-values($a/last),
        $first in distinct-values($a[last=$last]/first)
    order by $last, $first
    return
        <result>
            <author>
               <last>{ $last }</last>
               <first>{ $first }</first>
            </author>
            {
                for $b in doc("http://bstore1.example.com/bib.xml")/bib/book
                where some $ba in $b/author 
                      satisfies ($ba/last = $last and $ba/first=$first)
                return $b/title
            }
        </result>
  }
</results> 

The order in which values are returned by distinct-values() is undefined. The distinct-values() function returns atomic values, extracting the names from the elements.

Expected Result:

<results>
    <result>
        <author>
            <last>Abiteboul</last>
            <first>Serge</first>
        </author>
        <title>Data on the Web</title>
    </result>
    <result>
        <author>
            <last>Buneman</last>
            <first>Peter</first>
        </author>
        <title>Data on the Web</title>
    </result>
    <result>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
        <title>TCP/IP Illustrated</title>
        <title>Advanced Programming in the Unix environment</title>
    </result>
    <result>
        <author>
            <last>Suciu</last>
            <first>Dan</first>
        </author>
        <title>Data on the Web</title>
    </result>
</results>





For each book (in reviews xml file) found at both bstore1.example.com and bstore2.example.com, list the title of the book and its price from each source.

Solution in XQuery:

<books-with-prices>
  {
    for $b in doc("http://bstore1.example.com/bib.xml")//book,
        $a in doc("http://bstore2.example.com/reviews.xml")//entry
    where $b/title = $a/title
    return
        <book-with-prices>
            { $b/title }
            <price-bstore2>{ $a/price/text() }</price-bstore2>
            <price-bstore1>{ $b/price/text() }</price-bstore1>
        </book-with-prices>
  }
</books-with-prices>

Expected Result:

<books-with-prices>
    <book-with-prices>
        <title>TCP/IP Illustrated</title>
        <price-bstore2>65.95</price-bstore2>
        <price-bstore1>65.95</price-bstore1>
    </book-with-prices>
    <book-with-prices>
        <title>Advanced Programming in the Unix environment</title>
        <price-bstore2>65.95</price-bstore2>
        <price-bstore1>65.95</price-bstore1>
    </book-with-prices>
    <book-with-prices>
        <title>Data on the Web</title>
        <price-bstore2>34.95</price-bstore2>
        <price-bstore1>39.95</price-bstore1>
    </book-with-prices>
</books-with-prices> 






For each book that has at least one author, list the title and first two authors, and an empty "et-al" element if the book has additional authors.

Solution in XQuery:

<bib>
  {
    for $b in doc("http://bstore1.example.com/bib.xml")//book
    where count($b/author) > 0
    return
        <book>
            { $b/title }
            {
                for $a in $b/author[position()<=2]  
                return $a
            }
            {
                if (count($b/author) > 2)
                 then <et-al/>
                 else ()
            }
        </book>
  }
</bib>

Expected Result:

<bib>
    <book>
        <title>TCP/IP Illustrated</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </book>
    <book>
        <title>Advanced Programming in the Unix environment</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </book>
    <book>
        <title>Data on the Web</title>
        <author>
            <last>Abiteboul</last>
            <first>Serge</first>
        </author>
        <author>
            <last>Buneman</last>
            <first>Peter</first>
        </author>
        <et-al/>
    </book>
</bib> 


List the titles and years of all books published by Addison-Wesley after 1991, in alphabetic order.

Solution in XQuery:

<bib>
  {
    for $b in doc("http://bstore1.example.com/bib.xml")//book
    where $b/publisher = "Addison-Wesley" and $b/@year > 1991
    order by $b/title
    return
        <book>
            { $b/@year }
            { $b/title }
        </book>
  }
</bib> 

Expected Result:

<bib>
    <book year="1992">
        <title>Advanced Programming in the Unix environment</title>
    </book>
    <book year="1994">
        <title>TCP/IP Illustrated</title>
    </book>
</bib>     




Find books in which the name of some element ends with the string "or" and the same element contains the string "Suciu" somewhere in its content. For each such book, return the title and the qualifying element.

Solution in XQuery:

for $b in doc("http://bstore1.example.com/bib.xml")//book
let $e := $b/*[contains(string(.), "Suciu") 
               and ends-with(local-name(.), "or")]
where exists($e)
return
    <book>
        { $b/title }
        { $e }
    </book> 

In the above solution, string(), local-name() and ends-with() are functions defined in the Functions and Operators document.

Expected Result:

<book>
        <title>Data on the Web</title>
        <author>
            <last>Suciu</last>
            <first>Dan</first>
        </author>
 </book>




In the document "books.xml", find all section or chapter titles that contain the word "XML", regardless of the level of nesting.

Solution in XQuery:

<results>
  {
    for $t in doc("books.xml")//(chapter | section)/title
    where contains($t/text(), "XML")
    return $t
  }
</results> 

Expected Result:

<results>
    <title>XML</title>
    <title>XML and Semistructured Data</title>
</results> 




In the document "prices.xml", find the minimum price for each book, in the form of a "minprice" element with the book title as its title attribute.

Solution in XQuery:

<results>
  {
    let $doc := doc("prices.xml")
    for $t in distinct-values($doc//book/title)
    let $p := $doc//book[title = $t]/price
    return
      <minprice title="{ $t }">
        <price>{ min($p) }</price>
      </minprice>
  }
</results> 

Expected Result:

<results>
    <minprice title="Advanced Programming in the Unix environment">
        <price>65.95</price>
    </minprice>
    <minprice title="TCP/IP Illustrated">
        <price>65.95</price>
    </minprice>
    <minprice title="Data on the Web">
        <price>34.95</price>
    </minprice>
</results> 




For each book with an author, return the book with its title and authors. For each book with an editor, return a reference with the book title and the editor's affiliation.

Solution in XQuery:

<bib>
{
        for $b in doc("http://bstore1.example.com/bib.xml")//book[author]
        return
            <book>
                { $b/title }
                { $b/author }
            </book>
}
{
        for $b in doc("http://bstore1.example.com/bib.xml")//book[editor]
        return
          <reference>
            { $b/title }
            {$b/editor/affiliation}
          </reference>
}
</bib>  

Expected Result:

<bib>
    <book>
        <title>TCP/IP Illustrated</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </book>
    <book>
        <title>Advanced Programming in the Unix environment</title>
        <author>
            <last>Stevens</last>
            <first>W.</first>
        </author>
    </book>
    <book>
        <title>Data on the Web</title>
        <author>
            <last>Abiteboul</last>
            <first>Serge</first>
        </author>
        <author>
            <last>Buneman</last>
            <first>Peter</first>
        </author>
        <author>
            <last>Suciu</last>
            <first>Dan</first>
        </author>
    </book>
    <reference>
        <title>The Economics of Technology and Content for Digital TV</title>
        <affiliation>CITI</affiliation>
    </reference>
</bib> 




Find pairs of books that have different titles but the same set of authors (possibly in a different order).

Solution in XQuery:

<bib>
{
    for $book1 in doc("http://bstore1.example.com/bib.xml")//book,
        $book2 in doc("http://bstore1.example.com/bib.xml")//book
    let $aut1 := for $a in $book1/author 
                 order by $a/last, $a/first
                 return $a
    let $aut2 := for $a in $book2/author 
                 order by $a/last, $a/first
                 return $a
    where $book1 << $book2
    and not($book1/title = $book2/title)
    and deep-equal($aut1, $aut2) 
    return
        <book-pair>
            { $book1/title }
            { $book2/title }
        </book-pair>
}
</bib> 

Expected Result:

<bib>
    <book-pair>
        <title>TCP/IP Illustrated</title>
        <title>Advanced Programming in the Unix environment</title>
    </book-pair>
</bib>