Syntax for Specifying an Axis in a Query

The previous sections provide examples of XPath expression syntax that uses abbreviations. This section introduces you to the axis syntax that many of the abbreviations represent. For a list of XPath abbreviations, see XPath Abbreviations Quick Reference.

You can use axis syntax to specify a location path in a query. An axis specifies the tree relationship between the nodes selected by an expression and the context node. The syntax for specifying an axis in a query is as follows:

axis_name ::node_test

The axis names are defined in Supported Axes.

A node test is a simple expression that tests for a specified node type or node name. For example:

  • node() matches any type of node.
  • text() matches text or CDATA nodes.
  • comment() matches comment nodes.
  • processing-instruction() matches any processing instruction.
  • processing-instruction(name ) matches processing instructions whose target is name.
  • name matches elements or attributes whose name is name.
  • * matches any elements or any attributes.

XPath 2.0 adds additional tests, such as

  • element() matches any element node
  • attribute() matches any attribute node
  • document-node() matches any document node

In addition, you can follow the node test with any number of filters.

 
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