php实现登录注册

PHP 登录注册实现

数据库准备

创建用户表存储用户信息，表结构示例：

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL UNIQUE,
    email VARCHAR(100) NOT NULL UNIQUE,
    password VARCHAR(255) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

注册功能实现

处理用户提交的注册表单数据，验证并存储到数据库：

// 连接数据库
$db = new PDO('mysql:host=localhost;dbname=test', 'username', 'password');

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $username = trim($_POST['username']);
    $email = trim($_POST['email']);
    $password = password_hash($_POST['password'], PASSWORD_DEFAULT);

    // 验证输入
    if (empty($username) || empty($email) || empty($_POST['password'])) {
        $error = '所有字段必须填写';
    } else {
        // 检查用户名和邮箱是否已存在
        $stmt = $db->prepare("SELECT id FROM users WHERE username = ? OR email = ?");
        $stmt->execute([$username, $email]);

        if ($stmt->fetch()) {
            $error = '用户名或邮箱已存在';
        } else {
            // 插入新用户
            $stmt = $db->prepare("INSERT INTO users (username, email, password) VALUES (?, ?, ?)");
            if ($stmt->execute([$username, $email, $password])) {
                header('Location: login.php');
                exit;
            }
        }
    }
}

登录功能实现

验证用户凭据并创建会话：

session_start();

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

    $stmt = $db->prepare("SELECT id, username, password FROM users WHERE username = ?");
    $stmt->execute([$username]);
    $user = $stmt->fetch();

    if ($user && password_verify($password, $user['password'])) {
        $_SESSION['user_id'] = $user['id'];
        $_SESSION['username'] = $user['username'];
        header('Location: dashboard.php');
        exit;
    } else {
        $error = '用户名或密码错误';
    }
}

安全注意事项

密码必须使用password_hash()进行哈希处理，验证时使用password_verify()

会话管理要确保使用session_start()并在登录后设置适当的会话变量

所有数据库查询应使用预处理语句防止SQL注入

表单提交应进行CSRF防护，可通过添加隐藏令牌字段实现

前端表单示例

注册表单：

<form method="post">
    <input type="text" name="username" required placeholder="用户名">
    <input type="email" name="email" required placeholder="邮箱">
    <input type="password" name="password" required placeholder="密码">
    <button type="submit">注册</button>
</form>

登录表单：

<form method="post">
    <input type="text" name="username" required placeholder="用户名">
    <input type="password" name="password" required placeholder="密码">
    <button type="submit">登录</button>
</form>