使用MySQL和PHP创建一个公告板

创建一个简单的公告板涉及到几个关键步骤：

1. 创建数据库和表：

CREATE DATABASE noticeboard;
 
USE noticeboard;
 
CREATE TABLE messages (
    id INT AUTO_INCREMENT PRIMARY KEY,
    author VARCHAR(50) NOT NULL,
    message TEXT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

2. 创建一个简单的HTML表单来提交新公告：

<form action="submit.php" method="post">
    Author: <input type="text" name="author" /><br />
    Message: <textarea name="message"></textarea><br />
    <input type="submit" value="Post" />
</form>

3. 创建PHP脚本来处理表单提交并将数据插入到数据库中：

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "noticeboard";
 
// 检查输入是否为空
if(empty($_POST["author"]) || empty($_POST["message"])) {
    die("All fields are required.");
}
 
// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
 
// 检查连接
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
 
$stmt = $conn->prepare("INSERT INTO messages (author, message) VALUES (?, ?)");
$stmt->bind_param("ss", $author, $message);
 
$author = $_POST["author"];
$message = $_POST["message"];
 
if($stmt->execute()) {
    header("Location: success.php");
} else {
    echo "Error: " . $stmt->error;
}
 
$stmt->close();
$conn->close();
?>

4. 创建一个PHP脚本来显示公告：

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "noticeboard";
 
// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
 
// 检查连接
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
 
$result = $conn->query("SELECT * FROM messages ORDER BY id DESC");
 
if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "Author: " . $row["author"]. " - Message: " . $row["message"]. " - Posted on: " . $row["created_at"]. "<br>";
    }
} else {
    echo "0 results";
}
$conn->close();
?>

确保替换数据库连接信息中的your_username和your_password为实际的用户名和密码。这个公告板的简单版本就完成了，你可以根据需要添加更多功能，例如用户验证、分页显示公告、删除公告等。