Syntax

Purpose

INSERTXMLBEFORE inserts a user-supplied value into the target XML before the node indicated by the XPath expression. This function is similar to INSERTXMLAFTER, but it inserts before, not after, the target node. Compare this function with INSERTCHILDXML.

• XMLType_instance is an instance of XMLType.

• 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, then the context of the relative path defaults to the root node.

• 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;

WAREHOUSE_NAME                      Owners
----------------------------------- ------------------------------
New Jersey                          <Owner>GrandCo</Owner>
                                    <Owner>ThirdOwner</Owner>
                                    <Owner>LesserCo</Owner>