title: How to set DEFAULT ON UPDATE CURRENT_TIMESTAMP in mysql with sqlalchemy?
body: <p>I am creating table with sqlalchemy.</p>
  <pre><code>user = Table('users', Metadata,
  Column('datecreated', TIMESTAMP,                                  
              server_default=text('CURRENT_TIMESTAMP')),            
  Column('datemodified', TIMESTAMP,                                 
                 server_onupdate=text('CURRENT_TIMESTAMP')),
  )
  </code></pre>
  <p>But this will not set <code>DEFAULT ON UPDATE CURRENT_TIMESTAMP</code>.</p>
  <p>I checked out <a href="https://stackoverflow.com/q/2450593">How do you get SQLAlchemy to override MySQL &quot;on update CURRENT_TIMESTAMP&quot;</a> but that will for literal I need to wire that in create table definition.</p>