XML XQuery Node Constructors

How it works

Enclosed expressions use braces to insert values into a constructed element. The new node is a result, not a change to the source document on disk. Adding content in the returned value is different from the XQuery Update Facility, which Saxon-HE does not provide as an update service. Keep controlled vocabulary names separate from untrusted values and serialize the result according to the consumer’s contract.

Run the code

Use Saxon-HE 12.9 with Java 21 or newer. Download the official Java distribution, keep its dependency JARs in a lib folder, and save exchange.xml beside the example. On Windows the command is java -cp "lib/*" net.sf.saxon.Query -s:exchange.xml -q:query-constructors.xq !method=text. Use your actual Saxon JAR folder; the official archive may put dependencies in a nested lib directory, so include both folders in the Java classpath when needed. Saxon-HE does not supply XSD schema-aware processing or the XQuery Update Facility.

Download the complete query-constructors.xq source. Keep each lab in its own folder. Sources are served as text, not as public executable server scripts. Review the starting setup.

Example

xquery version "3.1";
let $result := <available>{
  for $packet in /exchange/packet[@available="true"]
  return <seed id="{$packet/@id}">{$packet/name/string()}</seed>
}</available>
return string-join($result/seed ! concat(@id, ":", string(.)), ";")

Expected result

p1:Marigold;p3:Basil

Two new seed nodes are created inside available. The final expression reads the constructed result into a concise checked output. The source still contains all three original packet elements.