Retrieve Distinct Values using XQuery

Question

The following query is returning me duplicate rows. How can we retrieve the distinct values? Can we use Distinct somewhere in this query? Please help me.
SELECT XMLQuery('<Update>
{ for $demo in (ora:view("TableA")),
$demo_audit in ora:view("TableA_AUDIT")
let $demo_id := $demo/ROW/ID/text(),
$demo_audit_trans_date := $demo_audit/ROW/DATE/text(),
$demo_audit_id := $demo_audit/ROW/ID/text(),
$demo_audit_type := $demo_audit/ROW/TYPE/text()
where $demo_id = $demo_audit_id and
$demo_audit_type = "U"
return
<result>
<type>U</type>
<id>{$demo_id}</id>
</result>}</Data>' RETURNING CONTENT)
FROM dual;

Answer 1

Geoff,
I tried distinct-values in both let and return; however the result isn't distinct. Is the usage correct?
SELECT XMLQuery('<Update>
{for   $a in ora:view("EMP")
       let   $a_empno         := distinct-values($a/ROW/EMPNO/text()),
             $a_ename         := $a/ROW/ENAME/text(),
             $a_job           := $a/ROW/JOB/text(),
             $a_mgr           := $a/ROW/MGR/text(),
             $a_deptno        := distinct-values($a/ROW/DEPTNO/text())
       return
       <op>
             <empno>{distinct-values($a_empno)}</empno>
<name>{$a_ename}</name>
<deptno>{distinct-values($a_deptno)}</deptno>
</op>}
</Update>'
RETURNING CONTENT)
FROM dual;
The output generated is given below:
<Update>
<op>
<empno>1</empno>
<name>Henry</name>
<deptno>10</deptno>
</op>
<op>
<empno>1</empno>
<name>Henry1</name>
<deptno>10</deptno>
</op>
</Update>