Fatal error: uncaught mysqli_SQL_exception: you have an error in your SQL syntax; check the manual that corresponds to your mariadb server version

Fatal error: Uncaught mysqli_sql_exception: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ' , 2)' at line 1 in C:\xampp\htdocs\macibas_4p\formsKD\services\order_item_services.php:46 Stack trace: #0 C:\xampp\htdocs\macibas_4p\formsKD\services\order_item_services.php(46): mysqli->query('INSERT INTO ord...') #1 C:\xampp\htdocs\macibas_4p\formsKD\index.php(72): OrderItemServices->insertOrderItem('Juris Priede', '28741234', '23.11.2022', 'Razer pele 24.1...', '2') #2 {main} thrown in C:\xampp\htdocs\macibas_4p\formsKD\services\order_item_services.php on line 46

<pre><?php
                if(isset($_POST['add'])){
                    $orderData = $_POST['order'];
                    $productData = $_POST['product'];
                    
                    $fName = explode(" ", $orderData)[0];
                    $lName = explode(" ", $orderData)[1];
                    
                    $customer = $fName." ".$lName;
                    
                    $customerPhone = explode(" ", $orderData)[2];
                    $orderDate = explode(" ", $orderData)[3];
                    $qnt = $_POST['quantity'];
                    $p = $_POST['product'];
                    $product = explode(" ", $productData)[0];
                    
                    
                   	$result = $orderItemService->insertOrderItem($customer, $customerPhone, $orderDate, $p, $qnt);
                        
                    if($result){
                        echo "<p>Order item data insertion has been successful</p><br>";
                    }else{
                        echo "<p>Order item data insertion hasnt been successful</p><br>";
                    }
                
                }
            ?>

<pre>public function insertOrderItem($customer, $phone, $orderDate, $product, $quantity){
            if($customer == null || $phone == null || $orderDate == null || $product == null){
                return false;
            }
            
            $orderItems = $this->selectAllOrderItems();
            
            if(sizeof($orderItems) > 0){
               foreach($orderItems as $orderItem){
                   $customerName = $orderItem->getOrder()->getCustomer()->getName();
                   $customerPhone = $orderItem->getOrder()->getCustomer()->getPhone();
                   
                   $orderDateCheck = date_create($orderDate);
                   $orderDateCheck = date_format($orderDateCheck, 'd.m.Y');
                   
                   $isOrder = $customerName == $customer && 
                       $customerPhone == $phone &&
                       $orderDateCheck == $orderItem->getOrder()->getOrderDate();
                   
                   $productName = $orderItem->getProduct()->getName();
                   $isProduct = $productName == $product;
                   
                   if($isOrder && $isProduct){
                       return false;
                   }
               } 
            }
            
            $orderService = new OrderServices();
            $orderID = $orderService->selectOrderID($customer, $phone, $orderDate);
            
            $productService = new ProductServices();
            $productID = $productService->selectProductID($product);
            
            if($quantity == null)
                $quantity = 1;
            
            $sql = "INSERT INTO ".$this->table."(order_id, product_id, quantity) VALUES ($orderID, $productID, $quantity)";

            $isInserted = $this->conn->query($sql);

            if($isInserted){
                return true;
            }
            else{
                return false;
            }
        }