Query Form
XQuery #1
(:
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.
:)
let $d := doc('bib.xml')
for $a in distinct-values($d//author)
return
<author name="{$a}">
{
for $b in $d//book[author=$a]
return $b/title
}
</author>
XQuery #2
(:
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.
:)
let $d := doc('bib.xml')
for $b in $d//book
return
<book title="{data($b/title)}">
{
for $a in $b/author[position() <= 2]
return $a
}
{
if (count($b/author) > 2)
then <et-al/>
else ()
}
</book>
XQuery #3
(:
Find all books such that:
1. the name of some element ends with the string "or" and the
same element contains the string "Dan" somewhere in its
content, and
2. some element contains the string "Morgan" somewhere in its
content.
For each such book, return the title and the
qualifying elements.
:)
let $d := doc('bib.xml')
for $b in $d//book
let $e1 := $b/*[contains(string(.), "Dan")
and ends-with(local-name(.), "or")]
let $e2 := $b/*[contains(string(.), "Morgan")]
where exists($e1) and exists($e2)
return
<book>
{ $b/title }
{ $e1 }
{ $e2 }
</book>
XQuery #4
(:
For each author, show his/her full name as a single string and the
number of books he/she has authored.
:)
let $d := doc('bib.xml')
for $da in distinct-values($d//author)
let $group := $d//author[. = $da]
return
<author
name="{concat($group[1]/first/text(), ' ', $group[1]/last/text())}"
published="{count($d//book[author = $group[1]])}" />
XQuery #5
(:
Find pairs of books that have different titles but the same set of
authors (possibly in a different order).
:)
let $d := doc('bib.xml')
for $book1 in $d//book, $book2 in $d//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 << $book2
and deep-equal($aut1, $aut2)
return
<book-pair>
{ $book1/title }
{ $book2/title }
</book-pair>
XQuery #6
(:
For each book with an author, return the book with its title and
authors. For each book with an editor, return reference with the
book title and the editor's affiliation.
:)
let $d := doc('bib.xml')
for $b in $d//book
return
if ($b[author]) then
<book>
{ $b/title }
{ $b/author }
</book>
else if ($b[editor]) then
<reference>
{ $b/title }
{ $b/editor/affiliation }
</reference>
else ()
XQuery #7
(:
Return the first and last name of all people who are authors
(or co-authors) of all the books.
:)
let $d := doc('bib.xml')
for $da in distinct-values($d//author)
let $group := $d//author[. = $da]
where
every $b in $d//book[author] satisfies
some $a2 in $b/author satisfies ($a2 = $group[1])
return $group[1]
XQuery #8
(:
Display the book information using year elements and, for
each year, display the title of the book as an attribute.
:)
let $d := doc('bib.xml')
for $a in $d//*[@year]
return <year book="{$a/title}"> {string($a/@year)} </year>
XQuery #9
(:
Display the total number of authors, both non-distinct and distinct.
:)
let $d := doc('bib.xml')
return
<authors
total="{count($d//author)}"
distinct="{count(distinct-values($d//author))}" />
XQuery #10: Your turn!
(:
Find all Witold Lipski's PhD students.
:)
XQuery #11: Your turn!
(:
Find all Alfred Tarski's descendants who graduated from a US university.
:)
XQuery #12: Your turn!
(:
Who are the common ancestors of Krzysztof Apt and Jan Chomicki?
:)
XQuery #13: Your turn!
(:
For every PhD recipient, compute the number of descendants.
:)
