【毕业设计】基于 PHP 开发的社区交流系统

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);
}
?>