specifying-an-axis-sqlxml-4-0.md

title	Specifying an Axis (SQLXML)
description	Learn how specifying an axis in an SQLXML 4.0 XPath query specifies the tree relationship between the nodes selected by the location step and the context node.
author	MikeRayMSFT
ms.author	mikeray
ms.date	03/04/2017
ms.service	sql
ms.subservice	xml
ms.topic	reference
helpviewer_keywords	XPath queries [SQLXML], axes XPath queries [SQLXML], location paths self axis attribute axis [SQLXML] axis [SQLXML] child axis parent axis location path for XPath query axes [SQLXML]
monikerRange	=azuresqldb-current||>=sql-server-2016||>=sql-server-linux-2017||=azuresqldb-mi-current

Specifying an Axis (SQLXML 4.0)

[!INCLUDE SQL Server Azure SQL Database]

• The axis specifies the tree relationship between the nodes selected by the location step and the context node. The following axes are supported: child

  Contains the child of the context node.

  The following XPath expression (location path) selects from the current context node all the <Customer> children:

  child::Customer  
  

  In the following XPath query, child is the axis. Customer is the node test.

• parent

  Contains the parent of the context node.

  The following XPath expression selects all the <Customer> parents of the <Order> children:

  child::Customer/child::Order[parent::Customer/@customerID="ALFKI"]  
  

  This is the same as specifying child::Customer. In this XPath query, child and parent are the axes. Customer and Order are the node tests.

• attribute

  Contains the attribute of the context node.

  The following XPath expression selects the CustomerID attribute of the context node:

  attribute::CustomerID  
  

• self

  Contains the context node itself.

  The following XPath expression selects the current node if it is the <Order> node:

  self::Order  
  

  In this XPath query, self is the axis and Order is the node test.