title: Oracle extract alpha characters from string
body: <p>I want to extract only alpha characters separately. <br>
  For example Output for "<strong>NIC132DA.1</strong>"  should be "<strong>NIC</strong>" and "<strong>DA</strong>" separately without any numbers.
  <br>
  I tried following query:<br></p>
  
  <pre><code>select regexp_replace('NIC132DA.1','[^A-Za-z]') from dual;
  </code></pre>
  
  <p>I get following output: <strong>NICDA</strong>
  <br> Expected out put is "NIC" and "DA" separately. 
  <br>Note: Number of alpha characters are not fixed in input string.</p>