65
XQuery
Find book titles by the coauthors of “Database Theory”:
FOR $x
IN bib/book[title/text()
= “Database Theory”]/author
$y IN bib/book[author/text() = $x/text()]/title
$y IN bib/book[author/text() = $x/text()]/title
RETURN
<answer> { $y/text() } </answer>
Result:
<answer>
abc </ answer >
< answer >
def </ answer >
< answer >
ghi </ answer >
The answer will
contain duplicates !
contain duplicates !