title: extracting text from a column using regexp_substr
body: <p>I have a table with a <em>varchar</em> column with data like this:</p>
  
  <pre><code>"&lt;tasa&gt;
    &lt;parametros&gt;
      &lt;parametro&gt;
        &lt;nombre&gt;ea&lt;/nombre&gt;
        &lt;valor&gt;35&lt;/valor&gt;
      &lt;/parametro&gt;
    &lt;/parametros&gt;
    &lt;valorTasa&gt;3.15&lt;/valorTasa&gt;
  &lt;/tasa&gt;"
  </code></pre>
  
  <p>I need to be able to extract the value between the <strong>valorTasa</strong> tags, but don't know how to use the function and can't access oracle documentation.</p>
  
  <p>I'm trying something like </p>
  
  <pre><code>select regexp_substr(field, '&lt;valorTasa&gt;[0-9]{0-3}&lt;/valorTasa') from dual;
  </code></pre>
  
  <p>With no results.
  Any help would be greatly appreciated</p>