title: How to create an auto-generated Date/timestamp field in a Play! / JPA?
body: <p>I'd like to add a Date/DateTime/Timestamp field on an entity object, that will be automatically created when the entity is created/persisted and set to "now", never to be updated again.</p>
  
  <p>Other use cases included fields that were always updated to contain the last modification date of the entity.</p>
  
  <p>I used to achieve such requirements <a href="https://stackoverflow.com/questions/168736/how-do-you-set-a-default-value-for-a-mysql-datetime-column">in the mysql schema</a>.</p>
  
  <p>What's the best way to do this in Play! / JPA?</p>