XQuery uses
XPath expressions to locate nodes in a document and to navigate from one location to another within a single document or across documents. Navigation paths defined using XPath consist of a sequence of steps separated by /. A single step comprises an axis, a node test, and zero or more step qualifiers.
The
axis specifies the direction of movement, relative to the context node. Supported axes in SQL Server 2005 are child, descendant, parent, attribute, self and descendant-or-self.
child : the children of the context node
descendant : all descendants (children, childrens children, ...)
parent : the parent (empty if at the root)
ancestor : all ancestors from the parent to the root
following-sibling : siblings to the right
preceding-sibling : siblings to the left
following : all following nodes in the document, excluding descendants
preceding : all preceding nodes in the document, excluding ancestors
attribute : the attributes of the context node
namespace : namespace declarations in the context node
self : the context node itself
descendant-or-self : the union of descendant and self
ancestor-or-self : the union of ancestor and self