public function retrieveTacheWithJoins(){
    return Doctrine_Query::create()
          ->select('
              t.*,
              e.*,
              tc.id_comment,
              tu.id_user,
              c.titre, c.comment, c.user_id, c.updated_at,
              cu.username,
              u.username
            ')
          ->from('Tache t')
          ->leftJoin('t.Etat e')
          ->leftJoin('t.TacheComment tc')
          ->leftJoin('tc.Comment c')
          ->leftJoin('c.sfGuardUser cu')
          ->leftJoin('t.TacheUser tu')
          ->leftJoin('tu.sfGuardUser u')
          ->execute(array(), Doctrine::HYDRATE_ARRAY);
  }