title: Must ORDER BY items appear in the select list if the statement contains a UNION operator?
body: <p>A sql script , It have run with no problem in production server for long time, 
  But lately system report "ORDER BY items Must appear in the select list if the 
  statement contains a UNION operator "</p>
  
  <p>It is strange that the sql script still can run in my test server. So I don't 
  know if any revision that I do can run correctly in production. </p>
  
  <pre><code>SELECT '' as value ,'Outstanding' as text , 0 as disp_order
  union
  select a.buyer_status_code AS value , a.buyer_status_name AS text ,a.disp_order
  FROM   rfq_buyer_status_v a WITH (NOLOCK)
  ORDER BY a.disp_order
  </code></pre>