Specifying Children or Descendants of Parent Nodes

Sometimes you want a query to return information about a sibling of the context node. One way to obtain a sibling is to define a query that navigates up to the parent and then down to the sibling.

For example, suppose the context node is the first author element. You want to find out the title associated with this author. The following query returns the associated title element:



The double dot ( ..) at the beginning of the query instructs the XPath processor to select the parent of the context node. This query returns the title elements that are children of the first book element, which is the parent of the first author element. In the bookstore.xml document, there is only one such title element.

Now suppose that the context node is still the first author element and you want to obtain the style attribute for the book that contains this author. The following query does this:



The double dot notation need not appear at the beginning of a query. It can appear anywhere in a query string, just like the dot notation.

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