XQuery: A typed functional language for querying XML

Abstract

XQuery is a typed, functional language for querying XML, currently being designed by the XML Query Working Group of the World-Wide Web Consortium. Here are examples of XQuery queries on a suitable XML document describing books. To list titles of all books published before 2000 you might write: document("books.xml")/BOOKS/BOOK[@YEAR < 2000]/TITLE To list the year and title of all books published before 2000 you might write: for $book in document("books.xml")/BOOKS/BOOK where $book/@YEAR < 2000 return 〈BOOK〉{ $book/@YEAR, $book/TITLE }〈/BOOK〉 And to list for each author the titles of all books by that author you might write: let $books := document("books.xml")/BOOKS for $author in distinct($books/BOOK/AUTHOR) return 〈AUTHOR NAME="{ $author }"〉{ $books/BOOK[AUTHOR = $author]/TITLE }〈/AUTHOR〉. © Springer-Verlag Berlin Heidelberg 2003.