title: Doctrine Many-to-many - how to access join(pivot) table?
body: <p>I'm making many-to many relatioships with categories and articles. But article must have "main" category, so in oters categories "rel="canonical"" to be placed. And logically to place it in join table.
  In Laravel there is wery simple mechanism to do so: <a href="http://laravel.com/docs/5.0/eloquent#working-with-pivot-tables" rel="nofollow">http://laravel.com/docs/5.0/eloquent#working-with-pivot-tables</a></p>
  
  <p>But I read about association mapping in Doctrine: <a href="http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/association-mapping.html" rel="nofollow">http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/association-mapping.html</a> - and there is no info about how to access or modify that table. Is there any way to do this in Doctrine?</p>