如何用PHP实现微信小程序的车辆追踪功能？

CREATE TABLE vehicle_location (
  id INT PRIMARY KEY AUTO_INCREMENT,
  latitude DECIMAL(10,6),
  longitude DECIMAL(10,6),
  timestamp INT
);

<?php
// 连接数据库
$mysqli = new mysqli("localhost", "用户名", "密码", "数据库名");

// 检查连接是否成功
if ($mysqli->connect_errno) {
    die("连接数据库失败: " . $mysqli->connect_error);
}

// 获得车辆位置
function getVehicleLocation($vehicleId) {
    global $mysqli;
    
    $query = "SELECT latitude, longitude, timestamp FROM vehicle_location WHERE id = ?";
    $stmt = $mysqli->prepare($query);
    $stmt->bind_param("i", $vehicleId);
    $stmt->execute();
    $stmt->bind_result($latitude, $longitude, $timestamp);

    $result = array();
    while ($stmt->fetch()) {
        $result[] = array(
            "latitude" => $latitude,
            "longitude" => $longitude,
            "timestamp" => $timestamp
        );
    }
    
    return $result;
}

// 更新车辆位置
function updateVehicleLocation($vehicleId, $latitude, $longitude) {
    global $mysqli;
    
    $timestamp = time();
    
    $query = "INSERT INTO vehicle_location (id, latitude, longitude, timestamp) VALUES (?, ?, ?, ?)";
    $stmt = $mysqli->prepare($query);
    $stmt->bind_param("iddi", $vehicleId, $latitude, $longitude, $timestamp);
    
    if ($stmt->execute()) {
        return true;
    } else {
        return false;
    }
}

// 处理请求
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $action = $_POST['action'];
    
    if ($action === 'getVehicleLocation') {
        $vehicleId = $_POST['vehicleId'];
        $result = getVehicleLocation($vehicleId);
        echo json_encode($result);
    } elseif ($action === 'updateVehicleLocation') {
        $vehicleId = $_POST['vehicleId'];
        $latitude = $_POST['latitude'];
        $longitude = $_POST['longitude'];
        $result = updateVehicleLocation($vehicleId, $latitude, $longitude);
        echo json_encode($result);
    }
}

// 关闭数据库连接
$mysqli->close();
?>

// 获取车辆位置
function getVehicleLocation(vehicleId) {
  wx.request({
    url: 'https://your-website.com/vehicle-tracker.php',
    method: 'POST',
    data: {
      action: 'getVehicleLocation',
      vehicleId: vehicleId
    },
    success: function(res) {
      var location = res.data[0];
      var latitude = location.latitude;
      var longitude = location.longitude;
      var timestamp = location.timestamp;
      
      // 在地图上显示车辆位置
      // ...
    }
  })
}

// 更新车辆位置
function updateVehicleLocation(vehicleId, latitude, longitude) {
  wx.request({
    url: 'https://your-website.com/vehicle-tracker.php',
    method: 'POST',
    data: {
      action: 'updateVehicleLocation',
      vehicleId: vehicleId,
      latitude: latitude,
      longitude: longitude
    },
    success: function(res) {
      // 更新成功
      // ...
    }
  })
}

// 调用函数示例
getVehicleLocation(1);
updateVehicleLocation(1, 39.9069, 116.3974);