I’ve this simple application built with Laravel and Eloquent, that should connect to a localhost phpmyAdmin Database.
I’ve got this method:

public function clickOrderPlateClient($id_client, $id_plate){
        $order = Order::where('id_client', $id_client)
            ->where('id_plate', $id_plate)
            ->first();

        $order->qt = ($order->qt) + 1;
        $order->save();
    }

which should increment by 1 the attribute “qt” in my table “orders” (described by the class Order) in the record corresponding to the given client which has ordered the given dish.

But I’m always getting an “Illegal offset type” error corresponding to the $order->save(); row.

error

this is my Order class:

<?php

namespace AppModels;

use IlluminateDatabaseEloquentFactoriesHasFactory;
use IlluminateDatabaseEloquentModel;

class Order extends Model
{
    protected $table ='orders';
    protected $primaryKey = ['id_client','id_plate'];
    public $timestamps = false;
    public $incrementing = false;

    public function getClient(){
        return $this->belongsTo('AppModelsClient','id_client');
    }

    public function getPlate(){
        return $this->belongsTo('AppModelsPlates','id_plate');
    }
}