Why does he not want to pull data from the database or does the variable not work?

Question

PHP

<?php
    $host = 'localhost';  // Хост, у нас все локально
    $user = 'test1';    // Имя созданного вами пользователя
    $pass = 'testtest11122'; // Установленный вами пароль пользователю
    $db_name = 'user1213408_test';   // Имя базы данных
    $link = mysqli_connect($host, $user, $pass, $db_name); // Соединяемся с базой

    // Ругаемся, если соединение установить не удалось
    if (!$link) {
      echo 'Не могу соединиться с БД. Код ошибки: ' . mysqli_connect_errno() . ', ошибка: ' . mysqli_connect_error();
      exit;
    }	
?>
<?php
   if (isset($_GET['id'])) {
      $sql = mysqli_query($link, "SELECT `ID`, `Name`, `Price`, `Nickname` FROM `product` WHERE `ID`={$_GET['id']}");
      $product = mysqli_fetch_array($sql);
    $order_id = isset($_GET['id']) ? $product['ID'] : ''; 
    $description = isset($_GET['id']) ? $product['Name'] : '';
    $amount = isset($_GET['id']) ? $product['Price'] : '';  
    $login = isset($_GET['id']) ? $product['Nickname'] : ''; 
   }
?>

variables

<?=$amount;?>
" . $login . "

I don't get anything I
would be grateful for any hint

Answer 1

one)

WHERE `ID`={$_GET['id']}

for this, in a decent society, they beat the clave on the kumpol, until complete enlightenment.
2) there is an important function that for some reason all beginners ignore - var_dump(); 100% solves problems, the main thing is to use it correctly and often.
3) If there is a request and there is a problem with its use - display the request (as a string) and run this request "manually", for example, through phpmyadmin.
4) Wang that the output of errors and warnings is turned off for you. See logs or turn on error output.

Answer 2

To work with the database, I highly recommend using RedBeanPHP ORM . Very good and handy item.