title: Insert xml into XmlType field
body: <p>I have this table in Oracle 11g:</p>
  
  <pre><code>create table tmp_test_xml (
      name_xml varchar2(4000),
      file_xml xmltype
  );
  </code></pre>
  
  <p>At this link <a href="http://docs.oracle.com/cd/B10500_01/appdev.920/a96620/xdb04cre.htm#1035571" rel="nofollow">oracle binding xmltype</a>, I have read that for a correct insert into a field <code>XMLType</code> I must to use the "Xmltype binding" as this insert:</p>
  
  <pre><code>insert into tmp_test_xml values (
            'file.xml',
            xmltype(
              '&lt;?xml version="1.0" encoding="UTF-8"?&gt;
              &lt;list_book&gt;
                  &lt;book&gt;1&lt;/book&gt;
                  &lt;book&gt;2&lt;/book&gt;
                  &lt;book&gt;3&lt;/book&gt;
              &lt;/list_book&gt;'
            )
  );
  </code></pre>
  
  <p>But, if I try to lunch this insert without the binding in <code>XMLType</code>, work very fine:</p>
  
  <pre><code>insert into tmp_test_xml values (
            'file.xml',
              '&lt;?xml version="1.0" encoding="UTF-8"?&gt;
              &lt;list_book&gt;
                  &lt;book&gt;1&lt;/book&gt;
                  &lt;book&gt;2&lt;/book&gt;
                  &lt;book&gt;3&lt;/book&gt;
              &lt;/list_book&gt;'
  );
  </code></pre>
  
  <p>Now, is facoltative use binding or not? What is the correct insert?</p>
  
  <p>Why the second insert works?</p>