基于 PHP 开发的社区交流系统可以是一个论坛、博客平台或是问答网站等形式的在线平台，用于用户之间的互动交流。以下是一个简单的 PHP 社区交流系统的示例，包括用户注册、登录、发布帖子、回复帖子等功能。
技术栈
- 前端：HTML, CSS, JavaScript
- 后端：PHP
- 数据库：MySQL
环境准备
- 安装 PHP 和 MySQL 服务。
- 安装 Web 服务器（如 Apache 或 Nginx）。
- 创建 MySQL 数据库。
数据库设计
创建一个名为 community_db 的数据库，并创建如下表结构：
- users 表：存储用户信息。
- posts 表：存储帖子信息。
- comments 表：存储评论信息。
CREATE DATABASE community_db;
USE community_db;
CREATE TABLE users (
id INT AUTO_INCREMENT PRIMARY KEY,
username VARCHAR(255) NOT NULL UNIQUE,
password VARCHAR(255) NOT NULL,
email VARCHAR(255) NOT NULL UNIQUE
);
CREATE TABLE posts (
id INT AUTO_INCREMENT PRIMARY KEY,
user_id INT NOT NULL,
title VARCHAR(255) NOT NULL,
content TEXT NOT NULL,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (user_id) REFERENCES users(id)
);
CREATE TABLE comments (
id INT AUTO_INCREMENT PRIMARY KEY,
post_id INT NOT NULL,
user_id INT NOT NULL,
content TEXT NOT NULL,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (post_id) REFERENCES posts(id),
FOREIGN KEY (user_id) REFERENCES users(id)
);
PHP 脚本
1. 用户注册 (register.php)
<?php
session_start();
require_once 'db.php';
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$username = $_POST['username'];
$email = $_POST['email'];
$password = password_hash($_POST['password'], PASSWORD_DEFAULT);
$stmt = $db->prepare("INSERT INTO users (username, email, password) VALUES (?, ?, ?)");
$stmt->bind_param("sss", $username, $email, $password);
if ($stmt->execute()) {
header("Location: login.php");
} else {
echo "Error: " . $stmt->error;
}
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Register</title>
</head>
<body>
<h1>Register</h1>
<form action="register.php" method="post">
Username: <input type="text" name="username" required><br>
Email: <input type="email" name="email" required><br>
Password: <input type="password" name="password" required><br>
<input type="submit" value="Register">
</form>
</body>
</html>
2. 用户登录 (login.php)
<?php
session_start();
require_once 'db.php';
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$username = $_POST['username'];
$password = $_POST['password'];
$stmt = $db->prepare("SELECT * FROM users WHERE username = ?");
$stmt->bind_param("s", $username);
$stmt->execute();
$result = $stmt->get_result();
if ($row = $result->fetch_assoc()) {
if (password_verify($password, $row['password'])) {
$_SESSION['user_id'] = $row['id'];
header("Location: index.php");
} else {
echo "Invalid username or password.";
}
} else {
echo "User not found.";
}
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Login</title>
</head>
<body>
<h1>Login</h1>
<form action="login.php" method="post">
Username: <input type="text" name="username" required><br>
Password: <input type="password" name="password" required><br>
<input type="submit" value="Login">
</form>
</body>
</html>
3. 主页 (index.php)
<?php
session_start();
require_once 'db.php';
if (!isset($_SESSION['user_id'])) {
header("Location: login.php");
exit;
}
$user_id = $_SESSION['user_id'];
$stmt = $db->query("SELECT * FROM posts ORDER BY created_at DESC");
$posts = $stmt->fetch_all(MYSQLI_ASSOC);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Community</title>
</head>
<body>
<h1>Welcome to the Community!</h1>
<a href="logout.php">Logout</a>
<h2>Create Post</h2>
<form action="create_post.php" method="post">
Title: <input type="text" name="title" required><br>
Content: <textarea name="content" required></textarea><br>
<input type="submit" value="Create Post">
</form>
<hr>
<?php foreach ($posts as $post): ?>
<h2><?php echo htmlspecialchars($post['title']); ?></h2>
<p><?php echo htmlspecialchars($post['content']); ?></p>
<a href="comment.php?id=<?php echo $post['id']; ?>">Comment</a>
<hr>
<?php endforeach; ?>
</body>
</html>
4. 创建帖子 (create_post.php)
<?php
session_start();
require_once 'db.php';
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$title = $_POST['title'];
$content = $_POST['content'];
$user_id = $_SESSION['user_id'];
$stmt = $db->prepare("INSERT INTO posts (user_id, title, content) VALUES (?, ?, ?)");
$stmt->bind_param("iss", $user_id, $title, $content);
if ($stmt->execute()) {
header("Location: index.php");
} else {
echo "Error: " . $stmt->error;
}
}
5. 发表评论 (comment.php)
<?php
session_start();
require_once 'db.php';
$post_id = intval($_GET['id']);
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$content = $_POST['content'];
$user_id = $_SESSION['user_id'];
$stmt = $db->prepare("INSERT INTO comments (post_id, user_id, content) VALUES (?, ?, ?)");
$stmt->bind_param("iii", $post_id, $user_id, $content);
if ($stmt->execute()) {
header("Location: comment.php?id=$post_id");
} else {
echo "Error: " . $stmt->error;
}
}
$stmt = $db->query("SELECT * FROM posts WHERE id = $post_id");
$post = $stmt->fetch_assoc();
$stmt = $db->query("SELECT * FROM comments WHERE post_id = $post_id");
$comments = $stmt->fetch_all(MYSQLI_ASSOC);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Comment on Post</title>
</head>
<body>
<h1><?php echo htmlspecialchars($post['title']); ?></h1>
<p><?php echo htmlspecialchars($post['content']); ?></p>
<h2>Add Comment</h2>
<form action="comment.php?id=<?php echo $post_id; ?>" method="post">
Content: <textarea name="content" required></textarea><br>
<input type="submit" value="Add Comment">
</form>
<hr>
<h2>Comments</h2>
<?php foreach ($comments as $comment): ?>
<p><?php echo htmlspecialchars($comment['content']); ?></p>
<?php endforeach; ?>
</body>
</html>
其他脚本
6. 注销 (logout.php)
<?php
session_start();
session_destroy();
header("Location: login.php");
exit;
数据库连接 (db.php)
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "community_db";
$db = new mysqli($servername, $username, $password, $dbname);
if ($db->connect_error) {
die("Connection failed: " . $db->connect_error);
}
?>
总结
以上代码展示了如何创建一个简单的基于 PHP 的社区交流系统，包括用户注册、登录、创建帖子、发表评论等功能。实际应用中还需要考虑安全性问题，如输入验证、SQL 注入防护等，并且可以增加更多功能，如搜索、分类、用户权限管理等。
