• Chapter 1: Getting Started with Stylus Studio
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
• Chapter 8: Defining Document Type Definitions
• Chapter 9: Writing XPath Expressions
  • About the XPath Processor
  • Sample Data for Examples and Testing
  • Getting Started with Queries
  • Specifying the Nodes to Evaluate
  • Handling Strings and Text
  • Specifying Boolean Expressions and Functions
  • Specifying Number Operations and Functions
  • Comparing Values
  • Finding a Particular Node
  • Obtaining a Union
  • Obtaining Information About a Node or a Node Set
  • Using XPath Expressions in Stylesheets
  • Accessing Other Documents During Query Execution
  • XPath Quick Reference
• Chapter 10: Working with XQuery in Stylus Studio
• Chapter 11: Composing Web Service Calls
• Chapter 12: Accessing Relational Data as XML
• Chapter 13: Extending Stylus Studio
• Chapter 14: Stylus Studio Reference

Home > Online Product Documentation > Table of Contents > Positions in Relation to Parent Nodes

Positions in Relation to Parent Nodes

Positions are relative to the parent. Consider the following data, which has line numbers on the left for explanation only.

1 	<x>
               
2 		<z>
               
3 		<z/>
               
4 	</x>
               
5 	<x>
               
6 		<y>
               
7 		<y/>
               
8	</x>
               
9	<x>
               
10		<y>
               
11		<y/>
               
12	</x>
               

            

The following query returns the first y element contained in each x element. It returns the elements on lines 6 and 10. The XPath processor finds all x elements. For each x element, the XPath processor then returns the first y element it finds.

x/y[1] 
               

            

The next query returns the first y element that is contained in an x element that is in the context node set. It returns the element on line 6. The XPath processor finds all y elements inside x elements. The XPath processor then returns the first element in that set.

(x/y)[1] 
               

            

The next query returns the empty set. The XPath processor finds the first x element. It then searches that first x element for the first y. Because the first x element does not contain a y element, this query returns the empty set.

x[1]/y[1]