PHP 学習ステップ: 権限制御管理システムの使用方法

CREATE TABLE `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(255) NOT NULL,
  `password` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
);

CREATE TABLE `permissions` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` int(11) NOT NULL,
  `permission` varchar(255) NOT NULL,
  PRIMARY KEY (`id`),
  FOREIGN KEY (`user_id`) REFERENCES `users`(`id`) ON DELETE CASCADE
);

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

// 程序继续执行...
?>

<form action="login.php" method="POST">
  <input type="text" name="username" placeholder="用户名">
  <input type="password" name="password" placeholder="密码">
  <input type="submit" value="登录">
</form>

<?php
session_start();

if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $username = $_POST["username"];
  $password = $_POST["password"];

  $sql = "SELECT * FROM users WHERE username = '$username' AND password = '$password'";
  $result = $conn->query($sql);

  if ($result->num_rows > 0) {
    $row = $result->fetch_assoc();
    $_SESSION["user_id"] = $row["id"];
    header("Location: dashboard.php");
  } else {
    echo "用户名或密码错误";
  }
}

$conn->close();
?>

<?php
session_start();

if(!isset($_SESSION["user_id"])){
  header("Location: login.php");
  exit;
}

$user_id = $_SESSION["user_id"];

$sql = "SELECT * FROM permissions WHERE user_id = $user_id AND permission = 'admin'";
$result = $conn->query($sql);

if ($result->num_rows == 0) {
  echo "权限不足";
  exit;
}

// 程序继续执行...
?>