如何编写子查询IN条件zend 2

Question

我有MySQL Query我想写这个查询zend 2.

(*p)[0]

在zend 2 am尝试这样写但是

select billsec,call_status,Count(*) from (select billsec,
if(ANSWERED_NUM is Null, 'Missed','Answered') call_status from cust_info 
where billsec in (SELECT id FROM `users` WHERE `account_id` = 452 AND `added_by` = 20694 AND `status` = 'active'))a 
group by a.billsec,a.call_status 

何时打印此查询输出如下：

$adapter   = $this->getAdapter();
    $resultset = $this->select( function( Select $select ) use ( $request, $adapter ) {
        $sub1  = new Select( 'users' );
        $sub1->columns( array( 'id'  ) );
        $sub1->where( array( 'account_id' => '452','added_by' => '20694','status' => 'active' ) );

        $sub2   = new Select( 'cust_info' );
        $sub2->columns(array("id","billsec", "if(ANSWERED_NUM is Null, 'Missed','Answered')"=>"call_status"));
        $sub2->where('billsec IN(?)', new \Zend\Db\Sql\Expression( '?', array( $sub1 ) ));


        var_dump( $sub2->getSqlString( $adapter->getPlatform() ) );die();
    });

这里无法写入IN条件查询，提前谢谢。