Call to undefined method Illuminate\Database\Query\Builder::isEmpty on eager loading laravel

Question

I have a Cart model like this :

class Cart extends Model
    {
        protected $table = 'cart';

        protected $fillable = ['user_id', 'delivery_method'];

        public function products ()
        {
            return $this->belongsToMany(Product::class, 'cart_products', 'cart_id', 'product_id')->withPivot('quantity');
        }

    }

And cart table columns are :

id
user_id
delivery_method
created_at
updated_at

And there is a pivot table named cart_products to relate Card model to a Product Model.

Suppose I have an specific $user_id variable. now I want Cart with that user_id with their products. for that I wrote this :

$cartWithProducts = Cart::with('products')->where(['user_id' => $user_id])->first();

if (!$cartWithProducts->isEmpty()) {
//Some codes come here
}

But after run, I got this error :

Call to undefined method Illuminate\Database\Query\Builder::isEmpty() {"exception":"[object] (BadMethodCallException(code: 0): Call to undefined method Illuminate\\Database\\Query\\Builder::isEmpty() at D:\\wamp\\www\\barlly\\vendor\\laravel\\framework\\src\\Illuminate\\Database\\Query\\Builder.php:2461

I do not want to use lazy loading approach beacause n query problem. what is solution in this case?

Also each User can have only one Cart in time.

When you call `first()`, it returns a single object or null. So, you are trying to call `isEmpty()`, which is a `Collection` method, on a single object. — Laerte, Jan 26 '18 at 18:31

score 12 · Accepted Answer · answered Jan 26 '18 at 18:28

12

you can just call

if ($cartWithProducts) {
//Some codes come here
}

Have a read over this Answer

answered Jan 26 '18 at 18:28

ATechGuy

1,240
8
13

I tired that, But if block does not run while I have a Card this that conditions in database. – Ahmad Badpey Jan 26 '18 at 18:32
1

Oops, I forgot to remove `!` – Ahmad Badpey Jan 26 '18 at 18:34
use ->get() instead of ->first() in your query – ATechGuy Jan 26 '18 at 19:21
But in this case it return an array of cart, right?. but I only save one cart for each `user_id` and now I want to select that one only – Ahmad Badpey Jan 26 '18 at 19:22

score 3 · Answer 2 · answered Jan 26 '18 at 18:39

Expecting your can have multiple carts for specified users and you may proceed more than one I would recommend to do something like this:

$cartWithProducts = Cart::whereUserId($user_id)->with('products')->get();

if ($cartWithProducts->isNotEmpty()) {
    //Some codes come here
}

score 2 · Answer 3 · answered Jan 26 '18 at 18:33

2

first() returns null if there is no Cart for the user, so if you want to check if it's empty, you can use is_null() or empty() instead of if (!$cartWithProducts) to keep is readable:

if (is_null($cartWithProducts))

answered Jan 26 '18 at 18:33

Alexey Mezenin

158,981
26
290
279

Call to undefined method Illuminate\Database\Query\Builder::isEmpty on eager loading laravel

3 Answers3