PHP大作业我的博客及详细代码

很棒！下面是一个简单的博客系统的示例代码：

1. 创建数据库表格

首先，我们需要创建一个MySQL数据库，并创建两个表格：`users`和`posts`。

CREATE TABLE `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) NOT NULL,
  `password` varchar(255) NOT NULL,
  `email` varchar(100) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE `posts` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) NOT NULL,
  `content` text NOT NULL,
  `author_id` int(11) NOT NULL,
  `created_at` datetime NOT NULL,
  PRIMARY KEY (`id`),
  KEY `author_id` (`author_id`),
  CONSTRAINT `posts_ibfk_1` FOREIGN KEY (`author_id`) REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

2. 创建PHP连接数据库的类

接下来，我们需要编写一个PHP类，用于连接数据库和执行一些常见的数据库操作。这里我们使用PDO来连接MySQL数据库。

class Database {
  private $host = 'localhost';
  private $username = 'root';
  private $password = 'password';
  private $database = 'blog';

  private $connection;

  public function __construct() {
    try {
      $dsn = "mysql:host={$this->host};dbname={$this->database}";
      $this->connection = new PDO($dsn, $this->username, $this->password);
      $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    } catch (PDOException $e) {
      die("Connection failed: " . $e->getMessage());
    }
  }

  public function query($sql) {
    $stmt = $this->connection->prepare($sql);
    $stmt->execute();
    return $stmt;
  }

  public function lastInsertId() {
    return $this->connection->lastInsertId();
  }
}

3. 用户登录和注册功能

接下来，我们需要编写用户登录和注册的功能。这里我们使用session来保存用户登录状态。

session_start();

if (isset($_POST['login'])) {
  $username = $_POST['username'];
  $password = $_POST['password'];

  $sql = "SELECT * FROM users WHERE username = :username";
  $stmt = $db->query($sql);
  $stmt->bindParam(':username', $username);
  $stmt->execute();
  $user = $stmt->fetch(PDO::FETCH_ASSOC);

  if ($user && password_verify($password, $user['password'])) {
    $_SESSION['user_id'] = $user['id'];
    header('Location: index.php');
    exit;
  } else {
    $error = 'Invalid username or password';
  }
}

if (isset($_POST['register'])) {
  $username = $_POST['username'];
  $password = $_POST['password'];
  $email = $_POST['email'];

  $sql = "INSERT INTO users (username, password, email) VALUES (:username, :password, :email)";
  $stmt = $db->query($sql);
  $stmt->bindParam(':username', $username);
  $stmt->bindParam(':password', password_hash($password, PASSWORD_DEFAULT));
  $stmt->bindParam(':email', $email);
  $stmt->execute();

  $_SESSION['user_id'] = $db->lastInsertId();

  header('Location: index.php');
  exit;
}

4. 添加博客文章

现在，我们可以添加博客文章了。我们需要一个表单，让用户输入文章标题和内容。当用户提交表单时，我们将文章信息插入到`posts`表中。

if (isset($_POST['create_post'])) {
  $title = $_POST['title'];
  $content = $_POST['content'];
  $author_id = $_SESSION['user_id'];
  $created_at = date('Y-m-d H:i:s');

  $sql = "INSERT INTO posts (title, content, author_id, created_at) VALUES (:title, :content, :author_id, :created_at)";
  $stmt = $db->query($sql);
  $stmt->bindParam(':title', $title);
  $stmt->bindParam(':content', $content);
  $stmt->bindParam(':author_id', $author_id);
  $stmt->bindParam(':created_at', $created_at);
  $stmt->execute();

  header('Location: index.php');
  exit;
}

5. 显示博客文章

最后，我们需要显示博客文章。我们从`posts`表中获取所有文章，并将它们显示在网页上。

$sql = "SELECT * FROM posts ORDER BY created_at DESC";
$stmt = $db->query($sql);
$posts = $stmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($posts as $post) {
  $sql = "SELECT * FROM users WHERE id = :id";
  $stmt = $db->query($sql);
  $stmt->bindParam(':id', $post['author_id']);
  $stmt->execute();
  $author = $stmt->fetch(PDO::FETCH_ASSOC);

  echo '<h1>' . $post['title'] . '</h1>';
  echo '<p>' . $post['content'] . '</p>';
  echo '<small>Written by ' . $author['username'] . ' on ' . $post['created_at'] . '</small>';
}

这就是一个简单的博客系统的示例代码。当然，它仅仅是一个示例，实际上你需要根据你的需求和想法进行修改和拓展。希望对你有所帮助！