yii中的子查询

Am trying to code for a subquery

select * from mob_reg where name in (select name from auth where
parent ="naga");

I followed all these answer's

[Sub-queries ActiveRecord Yii [How to set multiple condition on criteria for CActiveDataProvider?

But am getting invalid arguments for foreach().

   $model=new MobReg('search');
$model->unsetAttributes();


$criteria = new CDbCriteria(array(
    'select' => 't.imei, t.emp_name, t.email, t.name',
    'join' => 'INNER JOIN auth ON (t.name = auth.name AND auth.parent = :parent)',
    'group' => 't.id',
    'params' => array(':parent' => 'naga')
)); 
$dataProvider = new CActiveDataProvider('MobReg', array(
        'criteria'=>$criteria,
));

<?php $this->widget('zii.widgets.grid.CGridView', array(
    'id'=>'mob-reg-grid',
    'dataProvider'=>$dataProvider,
    'filter'=>$model,
    'columns'=>array(
        'imei',
        'emp_name',
                'email',
               'name',
        array(
            'class'=>'CButtonColumn',
        ),
    ),
)); ?>

What I have to replace? any idea? where am I going wrong?

I guess the problem am facing is in referencing two different tables, one in subquery and another in main query. how to handle this one?

What about something along the lines of:

$criteria = new CDbCriteria(array(
    'select' => 't.imei, t.emp_name, t.email, t.name',
    'join' => 'INNER JOIN auth ON (t.name = auth.name AND auth.parent = :parent)',
    'group' => 't.id',
    'params' => array(':parent' => 'naga')
));

$dataProvider = new CActiveDataProvider('MobReg', array(
       'criteria' => $criteria,
));

Would that work for you?