yii2里面的ActiveRecord-＞curd

<?php
namespace frontend\models;
use yii\db\ActiveRecord;
class Article extends ActiveRecord
{

}

<?php
namespace frontend\controllers;
use frontend\models\Article;
class IndexController extends \yii\web\Controller
{
	
	public function actionIndex()
	{//增加
		/*$article=new Article();
		$article->title="cyg";
		$article->created_at=time();
		$article->save();*/
		//修改
		/*$article=Article::findOne(['id'=>1]);
		$article->title="lwien";
		$article->save();*/
		//删除
		$article=Article::findOne(['id'=>1]);
		$article->delete();
	
}}