如何使用PHP实现表单提交后的数据存储

<form action="submit.php" method="POST">
  <label for="name">姓名：</label>
  <input type="text" name="name" id="name" required><br><br>
  
  <label for="email">邮箱：</label>
  <input type="email" name="email" id="email" required><br><br>
  
  <label for="message">留言：</label>
  <textarea name="message" id="message" required></textarea><br><br>
  
  <input type="submit" value="提交">
</form>

<?php
// 接收表单提交的数据
$name = $_POST['name'];
$email = $_POST['email'];
$message = $_POST['message'];

// 建立数据库连接
$servername = "localhost";
$username = "数据库用户名";
$password = "数据库密码";
$dbname = "数据库名";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 将数据存储到数据库中
$sql = "INSERT INTO 表名 (name, email, message)
        VALUES ('$name', '$email', '$message')";

if ($conn->query($sql) === TRUE) {
    echo "数据存储成功";
} else {
    echo "数据存储失败: " . $conn->error;
}

// 关闭数据库连接
$conn->close();
?>

CREATE DATABASE mydatabase;

USE mydatabase;

CREATE TABLE messages (
    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(30) NOT NULL,
    email VARCHAR(50) NOT NULL,
    message TEXT NOT NULL
);