title: Symfony Doctrine Models for Entity Without Primary Keys
body: <p>I'm working with a legacy database while re-building the web application. I want to use Symfony2.x which obviously has Doctrine as ORM. </p>
  
  <p>I've around 50 (mysql) tables which has NO Primary Keys. When I try to generate models, it does not let me do and throw an exception with "No Primary Key on ... table". </p>
  
  <p>Do I must have Primary Keys on tables to use Doctrine or is there any way around it?</p>
  
  <p>Any help would be great. </p>
  
  <p>Thanks.</p>