title: sqlalchemy literal text added to an insert
body: <p>I'm trying to get sqlalchemy to accept some more complex behavior on an insert, and can't figure out the idiomatic way to do it.  To simplify things, I was just trying to add a literal string to the end of the query, but can't find a valid way to do it.  I've seen the <strong>"text()"</strong> function use to add string literals to queries, but it wouldn't work the way I am using it. Here is an example of what I'm trying to do (this won't compile, but captures the idea at least...)</p>
  
  <pre><code>from sqlalchemy import *
  
  metadata = MetaData()
  
  user = Table('user', metadata,
      Column('user_id', Integer, primary_key = True),
      Column('likes', Integer, nullable = False),
      Column('last_liked', TIMESTAMP, nullable = False),
  )
  
  userid = 1
  newlikes = 5
  
  user.insert().values(user_id=userid, likes=newlikes) + 
      text("ON DUPLICATE KEY UPDATE last_liked=NOW(), likes = likes + " + newlikes)
  </code></pre>
  
  <p>Any recommendations would be appreciated. </p>