xxxxxxxxxx
$mysql_query = Yii::$app->db->createCommand("SELECT MAX(date) AS `lastDate` FROM `customers`")->queryOne();
$mysql_query = Yii::$app->db->createCommand("SELECT * FROM `customers`")->queryAll();
xxxxxxxxxx
$this->execute(" UPDATE example_table SET example_field = '1' WHERE example_field = '2' ");