title: Doctrine 2.0 | Create Database | Are Foreign Keys Unique
body: <ol>
  <li>I'm using Doctrine 2.0 and the latest version of MySQL aswell as PHP 5.3.5</li>
  <li>I currently use PHP mapping to create my database.  </li>
  </ol>
  
  <p>I have a model (Event) which has a one2one relationship with another model (EventInvitations) - this should probably be one2many but lets move on from that.  </p>
  
  <p>My current mapping for EventInvitations has a UniqueConstraint on an eventid and a userid.<br>
  My EventInivitation also has a OneToOne Join on Event, this is a Foreign Key</p>
  
  <p>when i run: "doctrine.php orm:schema-tool:update --force" Doctrine will successfully create my Unique index but it also seems to create another Uniq index which has a key name like Uniq_AHJHAUSH7J but on EventId field.</p>
  
  <p>The problem is that i dont want the Foreign Key to create a Unique Field.  Is there a way for me to tell Doctrine not to create the Unique index for the foreign key?</p>