Untitled

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>
    <?php
    $serwer = "localhost";
    $login = "root";
    $haslo = "";
    $baza = 'klasa';
    $tabela = 'uczen';

    $conn = mysqli_connect($serwer, $login, $haslo, $baza);

    ?>
    <form method="post">
        <input type="text" name="id" id="">
        <input type="text" name="name" id="">
        <input type="text" name="surname" id="">
        <input type="text" name="address" id="">
        <input type="submit" value="">
    </form>

    <?php

    $id = $_POST['id'];
    $name = $_POST['name'];
    $surname = $_POST['surname'];
    $address = $_POST['address'];

    $sql = " UPDATE uczen SET name='$name', surname='$surname', address='$address' WHERE idUcznia='$id'";

    if (mysqli_query($conn, $sql)) {
        echo "Record updated successfully";
    } else {
        echo "Error updating record: " . mysqli_error($conn);
    }
    mysqli_close($conn);

    ?>
</body>

</html>