|Oracle8i Application Developer's Guide - XML
Release 3 (8.1.7)
Part Number A86030-01
Introduction to Oracle XML, 16 of 27
Thus if the user has stored purchase_order as an XML document, to retrieve the first line item numbers of a particular document, you can execute a query such as:
SELECT extractNode(e.po_xml_column, `//line_item_list/itemno') FROM purchase_order_tab e WHERE e.pono = 100;
This example shows how SQL and XML querying can coexist. XPath behaves as a sublanguage within a SQL operator.
Two operators are provided, extractNode and existsNode:
The boolean operator is useful in predicates.
For example, the following query lists all documents which contain a line item with itemno equal to 100.