Как в yii2 query builder составляют запрос с текстовой строкой (literal string)?

$query = (new \yii\db\Query())
    ->select("CategoryID, CategoryName, CONCAT('Northwind Category', '' ) AS Note")
    ->from('categories');

$query = (new \yii\db\Query())
    ->select([
         'CategoryID', 
         'CategoryName', 
         'Note' => new  \yii\db\Expression("'Northwind Category'")])
    ->from('categories');