$criteria = new CDbCriteria;
$criteria->select = 'username,id,email';
$criteria->order = 'id DESC';
$users = modelName::model()->findAll( $criteria );

$users = modelName::model()->findAll(array(
  'select' =>array('username','id','email'),
  'order' => 'id DESC', 
));

$user = modelName::model()->find(array(
  'select' =>array('username','id','email'),
  'order' => 'id DESC',
  'condition' => 'id='.$id,
));

$users = $this->user->find(array(
  'select'=>array('id','username','email'),
  'order' => 'id DESC',
  'condition' => 'state=:state AND id=:id',
  'params' => array(':state'=>'1',':id' => '2'),
));

$criteria = new CDbCriteria() ; 
$criteria -> select = array('v_id','title','big_class','sub_class','upload_time','comment_num');     
$criteria -> condition = 'status = 1'; 
$criteria -> order = 'lastmodifytime desc'; 
$criteria -> limit = 3; 
 $criteria ->params = array (':status' => $你的变量) ; 
$result = VideoInfo::model()->findAll($criteria); 

$criteria -> condition = 'status = :status'; 

foreach ($result as $ob){ 
      print_r($ob->attributes); 
 } 

$ob->attributes['title']; 

      $count =VideoInfo::model()->count($criteria)

      $pages=new CPagination($count);    
      $pages->pageSize=30; //每页分多少条
      $pages->applyLimit($criteria); 

$result = VideoInfo::model()->findAll($criteria);