August 2003
Intermediate to advanced
512 pages
11h 23m
English
book
XQuery from the Experts: A Guide to the W3C XML Query Language
by Howard Katz - Editor, Don Chamberlin, Denise Draper, Mary Fernández, Michael Kay, Jonathan Robie, Michael Rys, Jérôme Siméon, Jim Tivy, Philip Wadler
Content preview from XQuery from the Experts: A Guide to the W3C XML Query Language
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Path Expressions
We saw earlier in the chapter many examples of path expressions. Here are some more:
$auction/articles has type element(articles) $auction/articles/article has type element(article)+ $auction/itesm/article is a static type error
These assume that $auction has type element(auction) as defined in Listing 4.2. The first expression has type element(articles) because there is exactly one articles element in an auction element. The second expression has type element(article)+ because there are one or more article elements in an articles element. The third expression is a static type error, because there is no itesm element in an auction element. Here is how the error is caught: the type rules assign to the last path expression the ...