Nested hierachy query to xml

Question

<pre>
To use dynatree(https://code.google.com/p/dynatree/) I want the result to be in the xml form.
but the result is not what I want.
can anybody help me?
SELECT
XMLELEMENT("div",xmlattributes('tree' AS "id"),
(SELECT DBMS_XMLGEN.getXMLType(
DBMS_XMLGEN.newContextFromHierarchy('
SELECT LEVEL,
case
when CONNECT_BY_ISLEAF = 0 then
XMLELEMENT("ul", XMLELEMENT("li", xmlattributes(empno AS "id"), ename))
when CONNECT_BY_ISLEAF = 1 then
XMLELEMENT("li", xmlattributes(empno AS "id"), ename)
end
FROM emp
START WITH mgr is null
CONNECT BY PRIOR empno = mgr '
) FROM DUAL
)) XMLDOC
FROM DUAL;
CURRENT RESULT
&lt;div id="tree"&gt;&lt;ul&gt;
&lt;li id="7839"&gt;KING&lt;/li&gt;
&lt;ul&gt;
&lt;li id="7566"&gt;JONES&lt;/li&gt;
&lt;ul&gt;
&lt;li id="7788"&gt;SCOTT&lt;/li&gt;
&lt;li id="7876"&gt;ADAMS&lt;/li&gt;
&lt;/ul&gt;
&lt;ul&gt;
&lt;li id="7902"&gt;FORD&lt;/li&gt;
&lt;li id="7369"&gt;SMITH&lt;/li&gt;
&lt;/ul&gt;
&lt;/ul&gt;
&lt;ul&gt;
&lt;li id="7698"&gt;BLAKE&lt;/li&gt;
&lt;li id="7499"&gt;ALLEN&lt;/li&gt;
&lt;li id="7521"&gt;WARD&lt;/li&gt;
&lt;li id="7654"&gt;MARTIN&lt;/li&gt;
&lt;li id="7844"&gt;TURNER&lt;/li&gt;
&lt;li id="7900"&gt;JAMES&lt;/li&gt;
&lt;/ul&gt;
&lt;ul&gt;
&lt;li id="7782"&gt;CLARK&lt;/li&gt;
&lt;li id="7934"&gt;MILLER&lt;/li&gt;
&lt;/ul&gt;
&lt;/ul&gt;
&lt;/div&gt;
DESIRED RESULT
&lt;ul&gt;
&lt;li id="7839"&gt;KING
&lt;ul&gt;
&lt;li id="7566"&gt;JONES
&lt;ul&gt;
&lt;li id="7788"&gt;SCOTT
&lt;ul&gt;
&lt;li id="7876"&gt;ADAMS&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;li id="7902"&gt;FORD
&lt;ul&gt;
&lt;li id="7369"&gt;SMITH&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;li id="7698"&gt;BLAKE
&lt;ul&gt;
&lt;li id="7499"&gt;ALLEN&lt;/li&gt;
&lt;li id="7521"&gt;WARD&lt;/li&gt;
&lt;li id="7654"&gt;MARTIN&lt;/li&gt;
&lt;li id="7844"&gt;TURNER&lt;/li&gt;
&lt;li id="7900"&gt;JAMES&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;li id="7782"&gt;CLARK
&lt;ul&gt;
&lt;li id="7934"&gt;MILLER&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
</pre>
Edited by: kang on Mar 5, 2013 8:27 PM

Answer 1

DBMS_XMLGEN.newContextFromHierarchy can only append children elements to their parents while walking the hierarchical tree down.
That means if a parent is :
<ul><li>KING</li></ul>then children are added to the &lt;ul> element, not to &lt;li> as you require.
Maybe you can explore one of the other solutions described here : http://odieweblog.wordpress.com/2011/11/24/how-to-generate-a-recursive-xml-structure/
Example with XQuery (requires 10.2) :
SQL> SELECT XMLSerialize(DOCUMENT
  2           XMLQuery(
  3           'declare function local:getEmployees($emps as element(ROW)*, $mgr as xs:integer?) as element()*
  4            {
  5              let $li :=
  6                for $i in $emps
  7                where $i/MGR = $mgr
  8                   or ( empty($mgr) and not(exists($i/MGR)) )
  9                order by $i/EMPNO
10                return
11                  <li id="{$i/EMPNO}">
12                  {
13                     $i/ENAME/text()
14                   , local:getEmployees($emps, $i/EMPNO)
15                  }
16                  </li>
17              return if ($li) then <ul>{$li}</ul> else ()
18            }; (: :)
19            <div id="tree">
20            {
21              local:getEmployees(fn:collection("oradb:/SCOTT/EMP")/ROW, ())
22            }
23            </div>'
24           returning content
25           )
26           AS CLOB INDENT
27         )
28  FROM dual
29  ;
XMLSERIALIZE(DOCUMENTXMLQUERY(
<div id="tree">
  <ul>
    <li id="7839">KING<ul>
        <li id="7566">JONES<ul>
            <li id="7788">SCOTT<ul>
                <li id="7876">ADAMS</li>
              </ul>
            </li>
            <li id="7902">FORD<ul>
                <li id="7369">SMITH</li>
              </ul>
            </li>
          </ul>
        </li>
        <li id="7698">BLAKE<ul>
            <li id="7499">ALLEN</li>
            <li id="7521">WARD</li>
            <li id="7654">MARTIN</li>
            <li id="7844">TURNER</li>
            <li id="7900">JAMES</li>
          </ul>
        </li>
        <li id="7782">CLARK<ul>
            <li id="7934">MILLER</li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</div>