mysqli登录注册

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = mysqli_connect($servername, $username, $password, $dbname);

// 检查连接
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// 注册
if ($_SERVER["REQUEST_METHOD"] == "POST" && isset($_POST['register'])) {
    $username = $_POST['username'];
    $password = password_hash($_POST['password'], PASSWORD_DEFAULT);
    $sql = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
    if (mysqli_query($conn, $sql)) {
        echo "New record created successfully";
    } else {
        echo "Error: " . $sql . "<br>" . mysqli_error($conn);
    }
}

// 登录
if ($_SERVER["REQUEST_METHOD"] == "POST" && isset($_POST['login'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];
    $sql = "SELECT * FROM users WHERE username = '$username'";
    $result = mysqli_query($conn, $sql);
    if (mysqli_num_rows($result) > 0) {
        $row = mysqli_fetch_assoc($result);
        if (password_verify($password, $row['password'])) {
            echo "Login successful";
        } else {
            echo "Invalid password";
        }
    } else {
        echo "User not found";
    }
}

mysqli_close($conn);
?>

<?php
$servername = "localhost";
$username = "username";
$password = "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);
}

// 注册
if ($_SERVER["REQUEST_METHOD"] == "POST" && isset($_POST['register'])) {
    $username = $_POST['username'];
    $password = password_hash($_POST['password'], PASSWORD_DEFAULT);
    $sql = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
    if ($conn->query($sql) === TRUE) {
        echo "New record created successfully";
    } else {
        echo "Error: " . $sql . "<br>" . $conn->error;
    }
}

// 登录
if ($_SERVER["REQUEST_METHOD"] == "POST" && isset($_POST['login'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];
    $sql = "SELECT * FROM users WHERE username = '$username'";
    $result = $conn->query($sql);
    if ($result->num_rows > 0) {
        $row = $result->fetch_assoc();
        if (password_verify($password, $row['password'])) {
            echo "Login successful";
        } else {
            echo "Invalid password";
        }
    } else {
        echo "User not found";
    }
}

$conn->close();
?>