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:
Contains the child of the context node.
This XPath expression (location path) selects from the current context node all the <Customer> children:
In this XPath query, child is the axis. Customer is the node test.
Contains the parent of the context node.
This XPath expression selects all the <Customer> parents of the <Order> children:
This is same as specifying Child::Customer. In this XPath query, child and parent are the axes. Customer and Order are the node tests.
Contains the attribute of the context node.
This XPath expression selects CustomerID attribute of the context node:
Contains the context node itself.
This XPath expression selects the current node if it is the <Order> node:
In this XPath query, self is the axis, and Order is the node test.