title: How to resolve ambigious colum after join in sqlalchemy
body: <p>When I join two tables (objects) using statement as </p>
  
  <pre><code>session.query(object, robject).filter(getattr(object.c, "hid")==getattr(robject.c,\
   )).subquery()
  </code></pre>
  
  <p>results in column reference "hid" is ambiguous since both tables have hid column. 
  How should I resolve this?</p>
  
  <p>Thanks  </p>