yii框架builder、update、delete使用方法

$connection = Yii::app()->db;
$mand = $connection->createCommand();
$operate_rst = 0;
if(!empty($_POST['lid'])){
    $operate_rst = $mand->update('emg_landing', $landing_info, 'lid=:lid', array(':lid' => $_POST['lid']));
}
else{
    $operate_rst = $mand->insert('emg_landing', $landing_info);
}
$connection->active = false;
if($operate_rst > 0){
    Functions::returnOk('OK!');
}
Functions::returnErrorJson();

{return}    integer    number of rows affected by the execution.