Execute Ms Sql Stored Procedure

Hi!

I've started using Yii just a couple of days ago.
Setting up was easy. I'm still learning the whole MVC architecture.
I need to execute stored procedures from a MS SQL Server Database.

I have a model class named Marcas:

<?php

/**
 * This is the model class for table "TblMarcas".
 *
 * The followings are the available columns in table 'TblMarcas':
 * @property integer $IDMarca
 * @property string $NomeMarca
 * @property string $DenominacaoSocial
 * @property string $Morada
 * @property string $Telefone
 * @property string $Data
 * @property string $PaginaWeb
 * @property string $TextoLivre
 * @property string $DataRegisto
 * @property string $DataAlteracao
 * @property string $UserRegisto
 * @property string $UserAlteracao
 *
 * The followings are the available model relations:
 * @property TblPackdeOpcoes[] $tblPackdeOpcoes
 * @property TblMarcaDoconcessionario[] $tblMarcaDoconcessionarios
 * @property TblModelos[] $tblModeloses
 */
class Marcas extends CActiveRecord
{
	/**
	 * Returns the static model of the specified AR class.
	 * @param string $className active record class name.
	 * @return Marcas the static model class
	 */
	public static function model($className=__CLASS__)
	{
		return parent::model($className);
	}

	/**
	 * @return string the associated database table name
	 */
	public function tableName()
	{
		return 'TblMarcas';
	}

	/**
	 * @return array validation rules for model attributes.
	 */
	public function rules()
	{
		// NOTE: you should only define rules for those attributes that
		// will receive user inputs.
		return array(
			array('IDMarca', 'required'),
			array('IDMarca', 'numerical', 'integerOnly'=>true),
			array('NomeMarca', 'length', 'max'=>25),
			array('DenominacaoSocial', 'length', 'max'=>100),
			array('Morada', 'length', 'max'=>200),
			array('Telefone, UserRegisto, UserAlteracao', 'length', 'max'=>20),
			array('PaginaWeb, TextoLivre', 'length', 'max'=>1073741823),
			array('Data, DataRegisto, DataAlteracao', 'safe'),
			// The following rule is used by search().
			// Please remove those attributes that should not be searched.
			array('IDMarca, NomeMarca', 'safe', 'on'=>'search'),
		);
	}

	/**
	 * @return array relational rules.
	 */
	public function relations()
	{
		// NOTE: you may need to adjust the relation name and the related
		// class name for the relations automatically generated below.
		return array(
			'tblPackdeOpcoes' => array(self::HAS_MANY, 'TblPackdeOpcoes', 'IDMarca'),
			'tblMarcaDoconcessionarios' => array(self::HAS_MANY, 'TblMarcaDoconcessionario', 'IDMarca'),
			'tblModeloses' => array(self::HAS_MANY, 'TblModelos', 'IDMarca'),
		);
	}

	/**
	 * @return array customized attribute labels (name=>label)
	 */
	public function attributeLabels()
	{
		return array(
			'IDMarca' => 'Idmarca',
			'NomeMarca' => 'Nome Marca',
			//'DenominacaoSocial' => 'Denominacao Social',
			//'Morada' => 'Morada',
			//'Telefone' => 'Telefone',
			//'Data' => 'Data',
			//'PaginaWeb' => 'Pagina Web',
			//'TextoLivre' => 'Texto Livre',
			//'DataRegisto' => 'Data Registo',
			//'DataAlteracao' => 'Data Alteracao',
			//'UserRegisto' => 'User Registo',
			//'UserAlteracao' => 'User Alteracao',
		);
	}

	/**
	 * Retrieves a list of models based on the current search/filter conditions.
	 * @return CActiveDataProvider the data provider that can return the models based on the search/filter conditions.
	 */
	public function search()
	{
		// Warning: Please modify the following code to remove attributes that
		// should not be searched.

		$criteria=new CDbCriteria;

		$criteria->compare('IDMarca',$this->IDMarca);
		$criteria->compare('NomeMarca',$this->NomeMarca,true);
		//$criteria->compare('DenominacaoSocial',$this->DenominacaoSocial,true);
		//$criteria->compare('Morada',$this->Morada,true);
		//$criteria->compare('Telefone',$this->Telefone,true);
		//$criteria->compare('Data',$this->Data,true);
		//$criteria->compare('PaginaWeb',$this->PaginaWeb,true);
		//$criteria->compare('TextoLivre',$this->TextoLivre,true);
		//$criteria->compare('DataRegisto',$this->DataRegisto,true);
		//$criteria->compare('DataAlteracao',$this->DataAlteracao,true);
		//$criteria->compare('UserRegisto',$this->UserRegisto,true);
		//$criteria->compare('UserAlteracao',$this->UserAlteracao,true);

		return new CActiveDataProvider($this, array(
			'criteria'=>$criteria,
			'sort'=>array(
            'defaultOrder'=>'NomeMarca ASC',
        ),
        'pagination'=>array(
            'pageSize'=>50
        ),
		));
	}

	public function showMarcas()
	{
		$marcas=array();
		$connection=Yii::app()->db;

		$result =$connection->createCommand("exec usp_pn_GetMarcas_Web")->queryColumn();
		foreach($result as $record)
		{
		array_push($marcas,$record['NomeMarca']);
		}

		return $marcas;
	}
}

My controller MarcasController:

class MarcasController extends Controller
{
	public function actionIndex()
	{
		$marcas = Marcas::model()->showMarcas();
		$this->render('index', array('model' => $marcas));
	}
}

And my view index.php

<?php
/* @var $this MarcasController */

$this->breadcrumbs=array(
	'Marcas',
);
?>
<h1><?php echo $this->id . '/' . $this->action->id; ?></h1>

&lt!--<p>
	You may change the content of this page by modifying
	the file <tt><?php echo __FILE__; ?></tt>.
</p>-->
<p>
	<?php 
		
		$marcas = Marcas::model()->showMarcas();
		$count_marcas = count($marcas);
		if($count_marcas > 0)
		{
			foreach($marcas as $marca) 
			{
				echo $marca->NomeMarca. '<br/>';
			}
		}
		
	?>
</p>

But nothing is displayed.

Can somebody please give me some input as to what I'm doing wrong?

Thank you very much.
Mário