WITH thinker AS(
  SELECT 1 AS THINKER_ID, 'Ciceron' AS THINKER_NAME, 'Roma' AS THINKER_PLACE FROM DUAL)
  
SELECT
  XMLELEMENT("thinker",
  XMLCONCAT(
    XMLELEMENT("ID",t.THINKER_ID),
    XMLELEMENT("ID",t.THINKER_NAME))) AS XML_ROW
FROM thinker t
-----------------------------------------
<thinker><ID>1</ID><ID>Ciceron</ID></thinker>