如何在cakephp 3.X中的select查询中键入cast数据库字段？

in my table, I have a decimal field of quantity. The value of 'quantity' in the database is 1.00 but when I selecting it from query, it is giving me integer 1. However, if the value will 1.25, it gives the same float value 1.25. Here is my query and output -

Query

$app_cart = $this->AppCart->find()->select(['AppCart.id','item'=>'Items.name','price'=>'Items.sales_rate','quantity'=>'AppCart.quantity'])
        ->where(['AppCart.user_id'=>1])->contain(['Items']);

Output

{
"success": true,
"message": "List Found",
"app_cart": [
    {
        "id": 4,
        "item": "KANGAN SAREE",
        "price": 1375,
        "quantity": 1
    },
    {
        "id": 5,
        "item": "KANGAN SAREE",
        "price": 1375,
        "quantity": 1
    }
]}

I have tried

$app_cart
        ->selectTypeMap()
        ->addDefaults([
            'quantity' => 'decimal'
        ]);