PHP Question

[Trigs]

Haven't done anything in PHP in around 6 months so I don't remember.

How do you count the number of users in a table again?

Also, how do I see what users are online? My system uses sessions so I guess I would set a cookie?

Sorry for the simple questions, but again, I haven't done anything in around 6 months.

[Trigs]

Also, I'm getting:


Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/fazon/public_html/test/config.php on line 42

It's coming from:

// User's info
$query = mysql_query("SELECT * FROM users WHERE username = '{$_SESSION['username']}'");
$users = mysql_fetch_array($query);

[RastaLulz]

To count the number of users you have you use mysql_num_rows()

Example:

<?php
include("config.php"); //where MySQL connection details are

$query = mysql_query("SELECT * FROM users"); //gets info from users
$count = mysql_num_rows($query); //counts the amount of users

echo $count; //echos the amount of users
?>

I don't know anything about PHP and sessions.

[Blinger1]

For the users online:

http://www.pixel2life.com/viewtutori...stem_tutorial/
http://www.pixel2life.com/viewtutori...rs_are_online/

either one

[Trigs]

Thanks guys, what about the error I get?

[RastaLulz]

Well, I don't know how to do it via sessions, but I could show you another way I do it. It may not be the best way of doing it, but it gets the job done.

First, I added a column to my "database", or whatever it's called to users called last_active. Every time a user is logged in, it gives them a time stamp and adds it to last_active (every page they load while logged in it updates the time stamp).

//last active
if($logged) {
      $time = date("omdHis");
      $updatetime = mysql_query("UPDATE users SET `last_active` = '$time' WHERE `username` = '$logged[username]'");
}else{

} 

Then I use the time stamp with a simple function that I created.

function whosonline() {
    //current time
    $timestamp = date("omdHis");

    //subtracts 15 minutes of the current time
    $subtract = (date('omdHis', strtotime('- 15 minutes')));

    $result = mysql_query("SELECT * FROM users WHERE `last_active` > '$subtract' ORDER BY username DESC");
    if(1 > mysql_num_rows($result)) {
        echo "There's currently no user online.";
    }else{
        //loops until everyone has been added
        while($online = mysql_fetch_array($result)) {

            //the users information
            $onlineuser = $online['username'];

            echo '<a href="profile/'.$onlineuser.'">'.$onlineuser.'</a> ';
        }
    }
} 

As I said above, it may not be the best, but it gives a rough idea of how you could do it.

[RastaLulz]

Ugh sorry for the double post (but we can't edit our previous posts which is lame), but I think that your getting an error because of the 's wrapped around username in the SQL query.

It should look like the following:
$_SESSION[username]

[LMS16]

Ugh sorry for the double post (but we can't edit our previous posts which is lame), but I think that your getting an error because of the 's wrapped around username in the SQL query.

It should look like the following:
$_SESSION[username]

Thats surely doesn't matter? I use $_SESSION["name"]; & $_SESSION['name']; all the time without errors...

Lew.

[RastaLulz]

Thats surely doesn't matter? I use $_SESSION["name"]; & $_SESSION['name']; all the time without errors...

Lew.

It surely gives me errors when I do it because it's cutting off the string (or whatever) when you do that.

[RastaLulz]

Sigh, something really needs to be done about editing posts.. :eusa_pray

But now that I think of it, it most likely isn't that because it'd return:

Parse error:  parse error, expecting `T_STRING' or `T_VARIABLE' or `T_NUM_STRING' in C:\xampp\htdocs\yoursite\file.php on line line

So, it's most likely that $_SESSION['username']; doesn't mean anything, because there's no argument for MySQL, but then again I could be wrong. But mysql_fetch_array has nothing to get, therefore it's putting out an error.