PHP学习笔记：论坛与博客系统开发

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  // 获取用户提交的表单数据
  $username = $_POST["username"]; 
  $password = $_POST["password"];
  $email = $_POST["email"];

  // 执行数据库插入操作
  $sql = "INSERT INTO users (username, password, email) VALUES ('$username', '$password', '$email')";
  // ... 执行SQL语句

  // 提示用户注册成功并跳转到登录页面
  echo "注册成功！请 <a href='login.php'>登录</a>";
}
?>

<form method="POST" action="">
  <label for="username">用户名：</label>
  <input type="text" name="username" id="username" required>

  <label for="password">密码：</label>
  <input type="password" name="password" id="password" required>

  <label for="email">电子邮件：</label>
  <input type="email" name="email" id="email" required>

  <input type="submit" value="注册">
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  // 获取用户提交的表单数据
  $username = $_POST["username"]; 
  $password = $_POST["password"];

  // 执行数据库查询操作
  $sql = "SELECT * FROM users WHERE username='$username' AND password='$password'";
  // ... 执行SQL语句

  // 检查数据库记录，如果匹配则登录成功，否则提示用户登录失败
  if ($result->num_rows > 0) {
    echo "登录成功！";
  } else {
    echo "登录失败！请检查您的用户名和密码。";
  }
}
?>

<form method="POST" action="">
  <label for="username">用户名：</label>
  <input type="text" name="username" id="username" required>

  <label for="password">密码：</label>
  <input type="password" name="password" id="password" required>

  <input type="submit" value="登录">
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  session_start(); // 开启会话
  $userId = $_SESSION["userId"]; // 获取当前登录用户的ID
  $title = $_POST["title"];
  $content = $_POST["content"];

  // 执行数据库插入操作
  $sql = "INSERT INTO posts (userId, title, content) VALUES ('$userId', '$title', '$content')";
  // ... 执行SQL语句

  // 提示用户发帖成功并跳转到论坛或博客页面
  echo "发帖成功！";
  echo "<a href='forum.php'>返回论坛</a> 或 <a href='blog.php'>返回博客</a>";
}
?>

<form method="POST" action="">
  <label for="title">标题：</label>
  <input type="text" name="title" id="title" required>

  <label for="content">内容：</label>
  <textarea name="content" id="content" required></textarea>

  <input type="submit" value="发帖">
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  session_start(); // 开启会话
  $userId = $_SESSION["userId"]; // 获取当前登录用户的ID
  $postId = $_POST["postId"];
  $comment = $_POST["comment"];

  // 执行数据库插入操作
  $sql = "INSERT INTO comments (postId, userId, comment) VALUES ('$postId', '$userId', '$comment')";
  // ... 执行SQL语句

  // 提示用户评论成功并返回到帖子页面
  echo "评论成功！";
  echo "<a href='post.php?id=$postId'>返回</a>";
}
?>

<form method="POST" action="">
  <input type="hidden" name="postId" value="postId">

  <label for="comment">评论：</label>
  <textarea name="comment" id="comment" required></textarea>

  <input type="submit" value="评论">
</form>