PHPとMQTTを利用したリアルタイム在庫管理・早期警報機能

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "inventory";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
// 检查连接是否成功
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 从数据库中读取产品的库存信息
$sql = "SELECT id, name, quantity FROM products";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    echo "<table>";
    echo "<tr><th>产品ID</th><th>产品名称</th><th>产品数量</th></tr>";
  
    while($row = $result->fetch_assoc()) {
        echo "<tr><td>".$row["id"]."</td><td>".$row["name"]."</td><td>".$row["quantity"]."</td></tr>";
    }
  
    echo "</table>";
} else {
    echo "暂无产品信息";
}

$conn->close();
?>

<?php
require("phpMQTT.php");

$server = 'localhost';     //MQTT服务器地址
$port = 1883;                     //MQTT服务器端口号
$username = 'username';   //MQTT用户名
$password = 'password';   //MQTT密码

$mqtt = new phpMQTT($server, $port, "PHP MQTT Client");
if (!$mqtt->connect(true, NULL, $username, $password)) {
    exit(1);
}

$topic = 'inventory/alert';      //MQTT主题
$message = '产品A库存不足，请及时补货！';  //预警消息

// 发布MQTT消息
$mqtt->publish($topic, $message, 0, false);

$mqtt->close();
?>

<?php
require("phpMQTT.php");

$server = 'localhost';     //MQTT服务器地址
$port = 1883;                     //MQTT服务器端口号
$username = 'username';   //MQTT用户名
$password = 'password';   //MQTT密码

$mqtt = new phpMQTT($server, $port, "PHP MQTT Client");
if (!$mqtt->connect(true, NULL, $username, $password)) {
    exit(1);
}

$topic = 'inventory/alert';      //MQTT主题

// 定义接收消息的回调函数
function messageReceived($topic, $message) {
    echo "接收到预警消息：[{$topic}] {$message}<br/>";
}

// 订阅MQTT主题并设置接收消息的回调函数
$mqtt->subscribe($topic, function($topic, $message){
    messageReceived($topic, $message);
}, 0);

while ($mqtt->proc()) { }

$mqtt->close();
?>