SESSION循环增加计数器

Question

My session checks if a user is logged , however when I refresh the page the session test runs again and starts to execute the code which then adds +1 to the members online counter everytime . I would like my code to check if the session is true like below but not if I refresh the page or navigate to another page .(Only Once per login) How can this be possible ?

PS MY code is not secure My code is not in any live environment , Security will be applied later to prevent sql injection .

 include('..\db.php');
    $con = mysqli_connect($dbsrvname, $dbusername, $dbpassword, $dbname);
    $guest_timeout = time() -1 * 60;
    $member_timeout = time() -2 * 60;
    $guest_ip = $_SERVER['REMOTE_ADDR'];
    $time = time()

    // This session check adds +1 to my member online counter when page is reloaded
    if(isset($_SESSION['CurrentUser'])){

        //if user is logged
        $sqlt = mysqli_query($con,"DELETE * FROM active_guests WHERE guest_ip='".$guest_ip."'");
        $sqlt2 = mysqli_query($con,"REPLACE INTO active_members VALUES ('".$_SESSION['CurrentUser']."','".$time."')");

    }else{

        //if user not logged
        $sqlt3 = mysqli_query($con,"REPLACE INTO active_guest (guest_ip,time_visited)VALUES ('".$guest_ip."','".$time."')");

    }
    $sqlt4 = mysqli_query($con,"DELETE * FROM  active_guest WHERE time_visited < ".$guest_timeout);
    $sqlt5 = mysqli_query($con,"DELETE * FROM  active_members WHERE time_visited < ".$member_timeout);
    $sqlt6 = mysqli_query($con,"SELECT guest_ip FROM active_guests");
    $online_guests = mysqli_num_rows($sqlt6);
    $sqlt7 = mysqli_query($con,"SELECT username FROM active_members");
    $online_members = mysqli_num_rows($sqlt7);
    ?>

    <div class="container">
    <p>online Guests : <?php echo $online_guests ; ?></p>
    <p>online Members : <?php echo $online_members ; ?></p>
    </div>

Answer 1

You need a unique index on the username column so that REPLACE will replace instead of inserting a duplicate row.

ALTER TABLE active_members ADD UNIQUE INDEX (username);

You probably also need a unique index on the guest_ip column of active_guests, although it's possible that multiple users could be coming from the same IP.