The name of an axis or an abbreviation for it.
In a location step, an AxisSpecifier determines the initial
node set originating in the context node. In practice it means that you
navigate through a document tree in a certain direction that is specified by
the axis. In the unabbreviated XPath syntax, you can use an
AxisName to determine the direction of navigation (for example
child:: selects the axis of child nodes in document order starting
at the context node).
Since unabbreviated axis specifiers are not supported in X-Query, you
can alternatively use an AbbreviatedAxisSpecifier to select the
child axis (AbbreviatedAxisSpecifier is empty) or the
attribute axis (AbbreviatedAxisSpecifier is
"@"). You can further use a
SequenceExpr to simulate navigation on the axes
following-sibling and preceding-sibling.
It corresponds to the expression AxisSpecifier defined in
XPath, Section
2.1, Rule 5, with the restriction that AxisName is not
supported in X-Query.
Select all medication that has been administered in the form of tablets
(starting from the root node select all descendant type nodes that
satisfy the following predicate expression: the value of the form
node on the attribute axis equals the string value
"tablet"):
//type[@form = 'tablet']
Step |