XQuery: A Typed Functional Language for Querying XML

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 { $book/@YEAR, $book/TITLE } 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 { $books/BOOK[AUTHOR = $author]/TITLE }