How to catch two tables without joining them with Zend1.12 query Builder?

Question

Based on documentation of Zend 1.12, using the Builder query:

How I select two tables with comma only without joinInner:

Example:

SELECT TABELA1 FROM 
(
 BLABLABLA...
) A, 
(SELECT TABELA2) B

To understand my problem, this is the code:

 $selectRankQuery = $this->dbTable->select()
        ->setIntegrityCheck(false)
       ->from(array('opn' => 'olympic_players_niveis'),
       array(
           'opn.user_id',
           'SUM(opn.points) as total_points'
       ));

       if ($olympic_id != null) {
          $selectRankQuery->where('opn.olympic_id = ? ', $olympic_id);
       } else {
          $selectRankQuery->joinInner(array('ol' => 'olympics'),
            'opn.olympic_id = ol.ID and ol.active = 1',
            array(
            ));
       }

       $selectRankQuery->group('opn.user_id');

       $init = new Zend_Db_Expr("SELECT @rank := 0");


        $select = $this->dbTable->select()
            ->setIntegrityCheck(false)
            ->from(array('rank_res' => $selectRankQuery),
            array(
                'rank_res.*',
                new Zend_Db_Expr('@rank := @rank + 1 rank')
            ))
            //o que eu uso aqui para ficar uma vírgula ????
            ->join(array('init' => $init));

             $r = $select->assemble();

I just need to start the variable @rank := 0 in select;

I tried this, but the query did not show the ranking value: ->from(array('rank_res' => $selectRankQuery, 'init' => $init);

Basically, this should be the way out:

SELECT 
    `rank_res`.*,

    @rank:=@rank + 1 rank
FROM
    (SELECT 
        `opn`.`user_id`, SUM(opn.points) AS `total_points`
    FROM
        `olympic_players_niveis` AS `opn`
    WHERE
        (opn.olympic_id = 9)
    GROUP BY `opn`.`user_id`) AS `rank_res`,
     (SELECT @rank:=0) AS `init`

Answer 1

I resolved it this way:

 $init = new Zend_Db_Expr(",(SELECT @rank := 0) init");

 $select = $this->dbTable->select()
            ->setIntegrityCheck(false)
            ->from(array('rank_res' => $selectRankQuery),
            array(
                'rank_res.*',
                new Zend_Db_Expr('@rank := @rank + 1 rank')
            ));

$select.=$init;