Cactivedataprovider怎么实现Group By

用group按column1聚合,然后统计每个聚合的数量, 如下:

    $groupSumDataProvider=new CActiveDataProvider('Statistics', array(


            'criteria' =>array(


                    'select'=>'count(*), column1',


                'group'=>'column1',


	        ),


    ));

发现生成的sql是:SELECT COUNT() FROM (SELECT count(), column1 FROM statistics t GROUP BY column1) sq

实际我想要的是:SELECT count(*), column1 FROM statistics GROUP BY column1

这个怎么做