Change the value of ENUM in database - php

Question

I am trying to change the value of an ENUM in a mySQL database that will help identify when a user is logged on or logged off on a website to be displayed to all users of the site. I set an ENUM column with possible values of 0 and 1. 0 being logged off, and 1 being logged on. But it doesnt seem to be changing anything. Here is my code:
//LOGIN
session_start();
$username = ($_POST['username']);
$password = ($_POST['password']);
$sql = "SELECT * FROM users WHERE username = '$username' LIMIT 1";
$query = mysqli_query($conn, $sql);
if ($query) {
$row = mysqli_fetch_row($query);
$userid = $row[0];
$dbusername = $row[1];
$dbpassword = $row[2];
$email = $row[4];
$status = $row[7];
$permit = $row[6];
$active = $row[5];
$fname = $row[8];
$lname = $row[9];
$dob = $row[10];
$signupdate = $row[3];
$ipadd = $row[11];
$loggedin = $row[12];
}
if ($username == $dbusername && $password == $dbpassword){
$_SESSION['username'] = $username;
$_SESSION['id'] = $userid;
$_SESSION['email'] = $email;
$_SESSION['status'] = $status;
$_SESSION['permit'] = $permit;
$_SESSION['email_activation'] = $active;
$_SESSION['first_name'] = $fname;
$_SESSION['last_name'] = $lname;
$_SESSION['dob'] = $dob;
$_SESSION['sign_up_date'] = $signupdate;
$_SESSION['ipv4'] = $ipadd;
$_SESSION['loggedin'] = $loggedin;
$sql = "UPDATE username SET loggedin = '1'";
header("Location: ../main.php");

Answer 1

Replace your update query with this one
"UPDATE users SET loggedin = '1' where `id` = $userid ";

Answer 2

//LOGIN
session_start();
$username = ($_POST['username']);
$password = ($_POST['password']);
$sql = "SELECT * FROM users WHERE username = '$username' LIMIT 1";
$query = mysqli_query($conn, $sql);
if ($query) {
$row = mysqli_fetch_row($query);
$userid = $row[0];
$dbusername = $row[1];
$dbpassword = $row[2];
$email = $row[4];
$status = $row[7];
$permit = $row[6];
$active = $row[5];
$fname = $row[8];
$lname = $row[9];
$dob = $row[10];
$signupdate = $row[3];
$ipadd = $row[11];
$loggedin = $row[12];
$sql = "UPDATE users SET loggedin = '1' where id = '$userid'";
mysqli_query($conn, $sql);
}
if ($username == $dbusername && $password == $dbpassword){
$_SESSION['username'] = $username;
$_SESSION['id'] = $userid;
$_SESSION['email'] = $email;
$_SESSION['status'] = $status;
$_SESSION['permit'] = $permit;
$_SESSION['email_activation'] = $active;
$_SESSION['first_name'] = $fname;
$_SESSION['last_name'] = $lname;
$_SESSION['dob'] = $dob;
$_SESSION['sign_up_date'] = $signupdate;
$_SESSION['ipv4'] = $ipadd;
$_SESSION['loggedin'] = $loggedin;
header("Location: ../main.php");