title: SQL Alchemy order_by with case
body: <p>I'm trying to do a query where one row should always come first and otherwise ordered ascending or descending.
  I'm using SQLAlchemy ORM.</p>
  
  <pre><code>the_case = case([(table.name != "foo", table.name)], else_="")
  
  a = db.query(table).order_by(the_case, asc(table.name)).all()
  b = db.query(table).order_by(the_case, desc(table.name)).all()
  </code></pre>
  
  <p>It works except a == b</p>