title: Ckeck the presence of xml tag using oracle
body: <pre><code> &lt;wbi:appData&gt;
       &lt;wbi:content wbi:name="1st_status"&gt;
           &lt;wbi:value xsi:type="xsd:string"&gt;Success&lt;/wbi:value&gt;
       &lt;/wbi:content&gt;
  &lt;/wbi:appData&gt;
  </code></pre>
  
  <p>this xml is in a table which has a column in the form of CLOB type.</p>
  
  <p>I wanted to find if "wbi:value" tag exists in this xml or not ?</p>
  
  <p>I tried using existsnode but in sql developer it is saying an error as to declare existsnode.</p>