title: execute immediate oracle string concatenate issue
body: <p>I am having issues concatenating a string to be called be execute immediate. Anybody have any idea what is wrong with the following statement below.  </p>
  
  <p>EXECUTE IMMEDIATE 'ALTER SESSION SET smtp_out_server = ''||SMTPServer||''';</p>
  
  <pre><code>select smtpserver into SMTPServer from mytable;
  
  if(SMTPServer is not null)
  then
    EXECUTE IMMEDIATE 'ALTER SESSION SET smtp_out_server = ''||SMTPServer||''';
    --*****above does not work, below does work****
    EXECUTE IMMEDIATE 'ALTER SESSION SET smtp_out_server = ''10.1.1.1''';
  </code></pre>