<?xml version="1.0"?>
 <EMP>
   <EMPNO>221</EMPNO>
   <ENAME>John</ENAME>
 </EMP>

<EMP>
   <EMPNO>221</EMPNO>
   <ENAME>John</ENAME>
 </EMP>

SQL> INSERT INTO clobtab VALUES (
  2  '<?xml version="1.0"?>
  3   <EMP>
  4     <EMPNO>221</EMPNO>
  5     <ENAME>John</ENAME>
  6   </EMP>');

SELECT (
  select XMLSerialize
  (
   CONTENT
    xmlelement("data",(select 1 from dual))
  )
  from dual
      )from dual

SELECT  XMLTYPE(
                (
                 select  XMLSerialize(
                                      CONTENT
                                      xmlelement("data",(select 1 from dual))
                                     )
                   from  dual
               )
              )
  from  dual
/

SQL> select XMLTYPE (
  2   XMLSerialize   (
  3     CONTENT
  4      xmlelement("data",(select 1 from dual))
  5    ))
  6  from dual
  7  /
XMLTYPE(XMLSERIALIZE(CONTENTXMLELEMENT("DATA",(SELECT1FROMDUAL))))
-------------------------------------------------------------------
<data>1</data>