html5显示mysql数据

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>显示 MySQL 数据</title>
</head>
<body>
    <h1>用户信息</h1>
    <table border="1">
        <tr>
            <th>ID</th>
            <th>姓名</th>
            <th>邮箱</th>
        </tr>
        <?php
        // 连接数据库
        $conn = new mysqli("localhost", "username", "password", "database_name");

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

        // 查询数据
        $sql = "SELECT id, name, email FROM users";
        $result = $conn->query($sql);

        // 显示数据
        if ($result->num_rows > 0) {
            while($row = $result->fetch_assoc()) {
                echo "<tr>";
                echo "<td>" . $row["id"] . "</td>";
                echo "<td>" . $row["name"] . "</td>";
                echo "<td>" . $row["email"] . "</td>";
                echo "</tr>";
            }
        } else {
            echo "<tr><td colspan='3'>没有数据</td></tr>";
        }

        // 关闭连接
        $conn->close();
        ?>
    </table>
</body>
</html>