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
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
External Functions and Variables
XQuery implementations are often embedded in an environment such as a Java or C# program or a relational database. The environment can provide external functions and variables to XQuery. To access these, a query must declare them in the prolog:
define function outtie($v as xs:integer) as xs:integer external define variable $v as xs:integer external
XQuery does not specify how such functions and variables are made available by the external environment, or how function parameters and arguments are converted between the external environment and XQuery.