It does not generate errors, but does not display echo.
// ПРОВЕРКА mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); $connect = mysqli_connect ("localhost","root","vertrigo","my_bd"); if (!$connect) { mysqli_error(); } if (isset($_POST['enter'])) { $enter_login = $_POST['enter_login']; $enter_pswd = md5($_POST['enter_pswd']); $sql = mysqli_query($connect, " SELECT * FROM users WHERE 'login' = '$enter_login' "); $user_data = mysqli_fetch_array($sql); if ($user_data['password'] == $enter_pswd) { echo 'HELLO HELLO HELLO HELLO HELLO'; } } mysqli_close($connect);