Specifying an Axis

The axis specifies the tree relationship between the nodes selected by the location step and the context node. These axes are supported:

• child

  Contains the child of the context node.

  This XPath expression (location path) selects from the current context node all the <Customer> children:

  child::Customer
  

  In this XPath query, child is the axis. Customer is the node test.

• parent

  Contains the parent of the context node.

  This XPath expression selects all the <Customer> parents of the <Order> children:

  child::Customer/child::Order[parent::Customer/@customerID="ALFKI"]
  

  This is same as specifying Child::Customer. In this XPath query, child and parent are the axes. Customer and Order are the node tests.

• attribute

  Contains the attribute of the context node.

  This XPath expression selects CustomerID attribute of the context node:

  attribute::CustomerID 
  

• self

  Contains the context node itself.

  This XPath expression selects the current node if it is the <Order> node:

  self::Order
  

  In this XPath query, self is the axis, and Order is the node test.