如何使用PHP编写库存管理系统中的订单配送功能代码

CREATE DATABASE inventory_management;

USE inventory_management;

CREATE TABLE orders (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT,
    product_id INT,
    quantity INT,
    address VARCHAR(255),
    status INT
);

<?php

class Delivery {
    private $db;

    public function __construct() {
        $this->db = new mysqli('localhost', 'username', 'password', 'inventory_management');

        if ($this->db->connect_errno) {
            die('连接失败: ' . $this->db->connect_error);
        }
    }

    public function deliverOrder($orderId) {
        // 检查订单是否存在
        $orderExists = $this->checkOrderExists($orderId);

        if (!$orderExists) {
            die('订单不存在');
        }

        // 检查订单配送状态
        $orderStatus = $this->checkOrderStatus($orderId);

        if ($orderStatus == 1) {
            die('订单已配送');
        }

        // 更新订单配送状态为已配送
        $updateQuery = "UPDATE orders SET status = 1 WHERE id = '$orderId'";

        if ($this->db->query($updateQuery)) {
            echo '订单配送成功';
        } else {
            echo '订单配送失败';
        }
    }

    private function checkOrderExists($orderId) {
        $query = "SELECT id FROM orders WHERE id = '$orderId'";

        $result = $this->db->query($query);

        if ($result->num_rows > 0) {
            return true;
        } else {
            return false;
        }
    }

    private function checkOrderStatus($orderId) {
        $query = "SELECT status FROM orders WHERE id = '$orderId'";

        $result = $this->db->query($query);

        if ($result) {
            $row = $result->fetch_assoc();

            return $row['status'];
        } else {
            return null;
        }
    }
}

?>

<?php

require_once('order_delivery.php');

$delivery = new Delivery();

$orderId = $_GET['order_id'];

$delivery->deliverOrder($orderId);

?>