yii 原生语句 增删改查

html:隐藏域<input type="hidden" name="_csrf" value="<?php echo yii::$app->request->csrfToken?>"><?phpnamespace app\controllers;use Yii;use yii\web\Controller;class IndexController extends  Controller{//显示表单界面public  function  actionIndex(){return $this->renderPartial('index');    }//执行添加public  function  actionAdd(){$connection = \Yii::$app->db;$arr = \Yii::$app->request->post();$connection->createCommand()->insert('ceshi',['title'=>$arr['title'],'username'=>$arr['username'],       ])->execute();$this->redirect(array('/index/list'));    }//查询数据库public  function  actionList(){$sql = "select * from ceshi";$connection=\Yii::$app->db->createCommand($sql);$arr=$connection->queryAll();return $this->renderPartial('list',['arr'=>$arr]);    }}