Path Expressions

Path Expressions

This type of expression is used to locate nodes in a given tree or XML document.

Expression:

Example(s):

Path Expressions

1. document("xqt")

In this first example (which is by default shown when the application is run), the output is simply the same as your input XML. The document() function is used here to access the XML source as an XQuery navigator collection, in which each navigator has its own name – in this case, ‘xqt’. We'll see more of this when we come to look at the code, later on in this tutorial.

2. <root> { document("xqt")//title } </root>

which in this case is basically the same as

<root>

{ document("xqt")/root/tutorials/tutorial/title }

</root>

The output shown is:

<?xml version="1.0"?>

<root>

  <title>Introduction to XQuery</title>

  <title>XQuery's Syntax</title>

  <title>XQuery: Advanced Tricks</title>

</root>

Here, the path expression selects every title that can be found in the XML source. From this xquery, a screenshot is added after the next third example.

3. <root>

     { document("xqt")//title/text() }

   </root>

Here, the input xquery is neatly formatted, but that does not influence the output in any way – it is just for readability and easy writing.

The output shown is:

<?xml version="1.0"?>

<root>Introduction to XQueryXQuery's

SyntaxXQuery: Advanced Tricks</root>

In this case, the values of the four found titles are concatenated into one string here (actually on one line) because the path expression contains text(). Note that whitespace or other special characters (like returns and linefeeds) located outside the element nodes are not outputted by the XSL processor.