SQL> select id, TYPEID, VALUE from MR_PRESIDENT t;
        ID TYPEID     VALUE
---------- ---------- --------------------------------------------------------------------------------
   1638508            
   1638508 1          iddqd

 

    select xmlelement("Parent",
                      xmlagg(xmlelement("iamachild", 
                                        xmlattributes(t.typeid as
                                                      "typeId"),
                                                      t.value)))
      from MR_PRESIDENT t
     where t._id = 1638508;

<Parent>
 <iamachild></iamachild>
 <iamachild typeId="1">iddqd</iamachild>
</Parent>

<Parent>
 <iamachild typeId="1">iddqd</iamachild>
</Parent>

SQL> select id, TYPEID, VALUE from MR_PRESIDENT t;
        ID TYPEID     VALUE
---------- ---------- --------------------------------------------------------------------------------
нет записей

<Parent>
 <iamachild></iamachild>
</Parent>