Yii 实现数据库SUM操作

$criteria = new CDbCriteria();  
$criteria->select = ‘sum(amount) total‘;  
$criteria->order = ‘wom_id desc’;  
$criteria->addCondition(“wom_id=4");//也可以$criteria->condition = "$wom_id=4";  
$aResult = Member::model()->findAll($criteria);

//获取账户已到帐总额
    public static function GetAmountAlreadyArrive($int_wom_id){
        $connection = Yii::app()->weimob_payment;
        $str_sql  = "select sum(`ww_amount`) as `total_balance` from `t_wm_weimobpay_withdrawal_new`";
        $str_sql .= " where wom_id={$int_wom_id} and ww_pay_status=1 and ww_check_status=1";
        $command = $connection->createCommand($str_sql);
        return $command->queryAll();
    }
    
    //获取账户提现总额
    public static function getCashamount($int_wom_id){
        $connection = Yii::app()->weimob_payment;
        $str_sql  = "select sum(`ww_amount`) as `total_balance` from `t_wm_weimobpay_withdrawal_new`";
        $str_sql .= " where wom_id={$int_wom_id} and ww_check_status!=2";
        $command = $connection->createCommand($str_sql);
        return $command->queryAll();
    }