title: Oracle 10g: Extract data (select) from XML (CLOB Type)
body: <p>I'm new in Oracle and I've - maybe trivial - a problem in a select. (I'm using Oracle 10g Express Edition).</p>
  
  <p>I've a DB with a field CLOB: mytab.xml
  This column have an XML like this:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="iso-8859-1"?&gt;
  &lt;info&gt;
  &lt;id&gt; 954 &lt;/id&gt;
  &lt;idboss&gt; 954 &lt;/idboss&gt;
  &lt;name&gt; Fausto &lt;/name&gt;
  &lt;sorname&gt; Anonimo &lt;/sorname&gt;
  &lt;phone&gt; 040000000 &lt;/phone&gt;
  &lt;fax&gt; 040000001 &lt;/fax&gt;
  &lt;/info&gt;
  </code></pre>
  
  <p>I'm trying to do a 'simple' select to get, for example, the value of 'fax' tag. But I've a bit of problem and I'm not able to understand my error. For example:</p>
  
  <pre><code>select extract(xml, '//fax').getStringVal() from mytab;
  ORA-00932: inconsistent datatypes: expected - got
  
  select extract(xmltype(xml), '//fax').getStringVal() from mytab;
  ORA-06502: PL/SQL: numeric or value error
  ORA-06512: at "SYS.XMLTYPE", line 254
  </code></pre>
  
  <p>I've tryed also with 'extractvalue', but I've the same problems.
  where I'm wrong to do this?</p>