登陆数据库，获取用户名和密码的PHP网页

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    password VARCHAR(255) NOT NULL
);

<?php
// 数据库连接信息
$servername = "localhost";
$username = "db_username";
$password = "db_password";
$dbname = "myDB";

// 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);
}

// 获取用户输入的用户名和密码
$myusername = $_POST['username'];
$mypassword = $_POST['password'];

// 对用户名和密码进行清理
$myusername = strip_tags($myusername);
$mypassword = strip_tags($mypassword);

// 查询数据库
$sql = "SELECT id, username, password FROM users WHERE username = '$myusername' AND password = '$mypassword'";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "登录成功";
        // 这里可以添加进一步的操作，比如重定向到用户的主页
    }
} else {
    echo "用户名或密码错误";
}

$conn->close();
?>