我已经创建了一个ims系统。因为我的库存为负数，我必须停止它，所以我的主要目的是在输入的产品超过可用库存时生成警报（例如，如果用户输入12个数量，而可用库存仅为10个数量，则警报消息应生成，如输入的数量超过可用库存，因此您无法生成警报）以下是我的代码

public function create()
    {
        $user_id = $this->session->userdata('id');
        $query = $this->db->query("SELECT bill_no FROM orders ORDER BY id DESC LIMIT 1");
        $result = $query->row()->bill_no;
        $result++;
        //echo $result;
        //end();
        //$curYear = date('Y');
        $invoice_no = $result;
        //$invoice['invoice_no'] = $invoice_no;
        $data = array(
            'po_no' => $this->input->post('po_no'),
            'po_date' => $this->input->post('po_date'),
            'challan_no' => $this->input->post('challan_no'),
            'challan_date' => $this->input->post('challan_date'),
            'bill_no' => $invoice_no,
            'bill_date' => $this->input->post('bill_date'),
            'terms' => $this->input->post('terms'),
            'dispatch' => $this->input->post('dispatch'),
            'party_id' => $this->input->post('id'),
            'name' => $this->input->post('name_value'),
            'address' => $this->input->post('address_value'),
            'gstin' => $this->input->post('gstin_value'),
            'mobile' => $this->input->post('mobile_value'),
            'date_time' => strtotime(date('Y-m-d h:i:s a')),
            'qty' => $this->input->post('qty_value'),
            'gross_amount' => $this->input->post('gross_amount_value'),
            'central_amount' => $this->input->post('central_amount_value'),
            'net_amount' => $this->input->post('net_amount_value'),
            'round_amount' =>$this->input->post('round_amount_value'),
            'round_amount_words' => $this->input->post('round_amount_words'),
            'paid_status' => 2,
            'user_id' => $user_id
        );
        $insert = $this->db->insert('orders', $data);
        $order_id = $this->db->insert_id();

        $this->load->model('model_products');

        $count_product = count($this->input->post('product'));
        for($x = 0; $x < $count_product; $x++) {
            $items = array(
                'order_id' => $order_id,
                'product_id' => $this->input->post('product')[$x],
                'hsn' => $this->input->post('hsn_value')[$x],
                'rate' => $this->input->post('rate')[$x],
                'qty' => $this->input->post('qty')[$x],
                'unit' => $this->input->post('unit_value')[$x],
                'amount' => $this->input->post('amount_value')[$x],
                'gst' => $this->input->post('gst_value')[$x],
                'gst_amount' => $this->input->post('gst_amount_value')[$x],
                'last_amount' => $this->input->post('last_amount_value')[$x],
            );

            $this->db->insert('orders_item', $items);

            // now decrease the stock from the product
            $product_data = $this->model_products->getProductData($this->input->post('product')[$x]);
            $qty = (int) $product_data['qty'] - (int) $this->input->post('qty')[$x];

            $update_product = array('qty' => $qty);

            $this->model_products->update($update_product, $this->input->post('product')[$x]);
        }

        return ($order_id) ? $order_id : false;
    }