PHP和MySQL搭建社交网站时用户系统的设计

<?php
// 连接到数据库
$conn = new mysqli("localhost", "username", "password", "database");

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

// 获取表单数据
$username = $_POST['username'];
$email = $_POST['email'];
$password = $_POST['password'];

// 对密码进行哈希处理
$hashed_password = password_hash($password, PASSWORD_DEFAULT);

// 插入新用户到数据库
$sql = "INSERT INTO users (username, email, password) VALUES (?, ?, ?)";
$stmt = $conn->prepare($sql);
$stmt->bind_param("sss", $username, $email, $hashed_password);

if ($stmt->execute()) {
    echo "新用户注册成功";
} else {
    echo "错误: " . $stmt->error;
}

$stmt->close();
$conn->close();
?>

<?php
// 连接到数据库
$conn = new mysqli("localhost", "username", "password", "database");

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

// 获取表单数据
$username = $_POST['username'];
$password = $_POST['password'];

// 查询用户
$sql = "SELECT id, password FROM users WHERE username = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("s", $username);
$stmt->execute();
$stmt->store_result();

if ($stmt->num_rows > 0) {
    $stmt->bind_result($id, $hashed_password);
    $stmt->fetch();

    if (password_verify($password, $hashed_password)) {
        // 登录成功
        echo "登录成功";
        // 这里可以设置会话或生成令牌
    } else {
        echo "密码错误";
    }
} else {
    echo "用户不存在";
}

$stmt->close();
$conn->close();
?>

<?php
// 生成唯一的重置令牌
$reset_token = bin2hex(random_bytes(32));

// 更新用户的重置令牌
$sql = "UPDATE users SET reset_token = ? WHERE email = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("ss", $reset_token, $email);

if ($stmt->execute()) {
    // 发送重置链接的电子邮件
    $reset_link = "http://example.com/reset-password.php?token=" . $reset_token;
    $to = $email;
    $subject = "密码重置";
    $message = "请点击以下链接重置密码: " . $reset_link;
    $headers = "From: webmaster@example.com" . "\r\n";

    mail($to, $subject, $message, $headers);
    echo "重置链接已发送到您的电子邮件";
} else {
    echo "错误: " . $stmt->error;
}

$stmt->close();
?>

<?php
// 假设用户已登录，获取用户ID
$user_id = $_SESSION['user_id'];

// 查询用户角色
$sql = "SELECT role_id FROM user_roles WHERE user_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $user_id);
$stmt->execute();
$stmt->bind_result($role_id);
$stmt->fetch();

// 根据角色ID查询权限
$sql = "SELECT permission FROM role_permissions WHERE role_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $role_id);
$stmt->execute();
$stmt->bind_result($permission);

$user_permissions = array();
while ($stmt->fetch()) {
    $user_permissions[] = $permission;
}

// 现在$user_permissions数组包含了用户的所有权限
?>