Navigating XML in Oracle

A few code snippets for navigating and extracting dynamically from XML in PL/SQL.

--The executable section of the traverse_and_display procedure. 
BEGIN
  -- get all elements
  nodes := xmldom.getElementsByTagName (doc, '*');

  -- loop through elements
  FOR node_index IN 0 .. xmldom.getLength (nodes) - 1
  LOOP
     one_node := xmldom.item (nodes, node_index);

     display_element (one_node);

     node_map := xmldom.getAttributes (one_node);

     FOR attr_index IN
        0 .. xmldom.getLength (node_map) - 1
     LOOP
        display_attribute (node_map, attr_index);
     END LOOP;
  END LOOP;
END traverse_and_display;



-- The code required for displaying the name and value of an element. 
PROCEDURE display_element (node IN xmldom.DOMNode)
IS
  one_element   xmldom.DOMElement;
  value_node    xmldom.DOMNode;
BEGIN
  one_element := xmldom.makeElement (node);
  DBMS_OUTPUT.put_line ('Element: ' ||
                       xmldom.getTagName (one_element
                       )
  );
  value_node := xmldom.getFirstChild (node);
  DBMS_OUTPUT.put_line ('Value: ' ||
                       xmldom.getNodeValue (value_node
                       )
  );
END;



--Displaying the value of an attribute. 
PROCEDURE display_attribute (
  node_map     IN   xmldom.DOMNamedNodeMap,
  attr_index   IN   PLS_INTEGER
)
IS
  one_node   xmldom.DOMNode;
  attrname   VARCHAR2 (100);
  attrval    VARCHAR2 (100);
BEGIN
  one_node := xmldom.item (node_map, attr_index);
  attrname := xmldom.getNodeName (one_node);
  attrval := xmldom.getNodeValue (one_node);
  DBMS_OUTPUT.put_line ('   ' || 
        attrname || ' = ' || attrval
  );
END;