EXISTSNODE

Note:

The EXISTSNODE function is deprecated. It is still supported for backward compatibility. However, Oracle recommends that you use the XMLEXISTS function instead. See XMLEXISTS for more information.

Syntax

Description of the illustration existsnode.gif

Purpose

EXISTSNODE determines whether traversal of an XML document using a specified path results in any nodes. It takes as arguments the XMLType instance containing an XML document and a VARCHAR2 XPath string designating a path. The optional namespace_string must resolve to a VARCHAR2 value that specifies a default mapping or namespace mapping for prefixes, which Oracle Database uses when evaluating the XPath expression(s).

The namespace_string argument defaults to the namespace of the root element. If you refer to any subelement in Xpath_string, then you must specify namespace_string, and you must specify the "who" prefix in both of these arguments.

See Also:

"Using XML in SQL Statements" for examples that specify namespace_string and use the "who" prefix.

The return value is NUMBER:

0 if no nodes remain after applying the XPath traversal on the document
1 if any nodes remain

Examples

The following example tests for the existence of the /Warehouse/Dock node in the XML path of the warehouse_spec column of the sample table oe.warehouses:

SELECT warehouse_id, warehouse_name
  FROM warehouses
  WHERE EXISTSNODE(warehouse_spec, '/Warehouse/Docks') = 1
  ORDER BY warehouse_id;

WAREHOUSE_ID WAREHOUSE_NAME
------------ -----------------------------------
           1 Southlake, Texas
           2 San Francisco
           4 Seattle, Washington