INSERTXMLBEFORE

Syntax

Description of the illustration insertXMLBefore.gif

Purpose

INSERTXMLBEFORE inserts a user-supplied value into the target XML before the node indicated by the XPath expression. Compare this function with INSERTCHILDXML.

• XMLType_instance is an instance of XMLType.

• The XPath_string is an Xpath expression indicating one or more nodes into which one or more child nodes are to be inserted. You can specify an absolute XPath_string with an initial slash or a relative XPath_string by omitting the initial slash. If you omit the initial slash, the context of the relative path defaults to the root node.

• The value_expr is a fragment of XMLType that defines one or more nodes being inserted and their position within the parent node. It must resolve to a string.

• The optional namespace_string provides namespace information for the XPath_string. This parameter must be of type VARCHAR2.

Examples

The following example is similar to that for INSERTCHILDXML, but it adds a third /Owner node before the /Owner node added in the other example. The output of the query has been formatted for readability.

UPDATE warehouses SET warehouse_spec =
   INSERTXMLBEFORE(warehouse_spec,
   '/Warehouse/Building/Owner[2]',
   XMLType('<Owner>ThirdOwner</Owner>'))
   WHERE warehouse_id = 3;

SELECT warehouse_name, EXTRACT(warehouse_spec, 
   '/Warehouse/Building/Owner') "Owners"
   FROM warehouses
   WHERE warehouse_id = 3;

Name         Owners
------------ --------------------------------------------------------------------
New Jersey <Owner>Grandco</Owner>
           <Owner>ThirdOwner</Owner>
           <Owner>LesserCo</Owner>