Is it wise to code who's online like this for a big site?

mband2000

Ok.. after a day of going crazy trying to search for help with building a who's online script.. i finally came up with this little solution... BUT.. I'm not sure if it's a good way to keep track of online users... here is the code. I'll explain afterwards.

<?
$oTime = time();
$pastTime = time()-300;
$db = mysql_connect("localhost", "root");
mysql_select_db("test", $db);
mysql_query("UPDATE users SET oTime = '".$oTime."' WHERE username ='".$logged_in_user."'");
mysql_query("UPDATE users SET iTime = 0 WHERE oTime < '".$pastTime."'");
?>

Basically I've added a field to my user table that says "oTime" and what I've done is added the code above to all my php pages.. so that when the user loads the page.. the script sends the current time to the user table.

It also at the same time updates the table to set a user's time to zero if their time hasn't been updated within the past 5 minutes.

When I create my whosonline.php page I just add the following to query the results..

<?
	$db = mysql_connect("localhost", "root");
	mysql_select_db("test", $db);
	$query = "SELECT username FROM users WHERE iTime != 0 ORDER BY RIGHT(username, 2) ASC";
	$result = mysql_query($query);
	while ($record = mysql_fetch_assoc($result)) {
		while (list ($fieldname, $fieldvalue) = each ($record)) {
			echo $fieldname.": <b><a href='profile.php?name=".$fieldvalue."'>".$fieldvalue."</a></b><br>";
		}
		echo "<br>";
	}
?>

What do you guys think? if this too much for a server that has a lot of visitors? I'm running a Windows p4 with 1.5gb ram.

If you know of any other ways of doing a better who's online script please let me know... because I'm a total newbie at all of this..:glare:

shorty114

It won't be the most efficient PHP script out there, since everytime you have to query the database. No, with your specs it won't be that bad compared to other machines.

What type of website is this?

mband2000

It will be a member community type site.. where users can view profiles of other users and send them private messages.

Actually its not being made for a real site... it's just that I'm learning PHP so I'm making this site on my local PC... I may test it as a real website to see how much server load it takes up.

shorty114

Yes, it will add extranous load because of the MySQL querying, but it won't add much.

mband2000

Would you happen to know of a better way to do this? I've been searching everywhere.. can't find anything I understand🙁

tsinka

Hi,

two points. If you have user ids (as primary key) in the users table I'd suggest to use the user id to update the otime. If you use the username I'd suggest to at least add an index to the username field. Especially if the users table gets very big this update query will slow down without an index.

The second update with iTime=0 doesn't really have to be executed each time a script is loaded. I'd suggest to add a scheduled task using the Windows task scheduler that executes a php script every 5 minutes to update the iTime (add an index to the oTime amd iTime fields, too).

Is there a reason for using RIGHT(username, 2) in the SELECT query ?

Thomas

mband2000

Hey thanks a lot!

The reason I was using RIGHT(username, 2) was to sort the online users alpabetically. Is that not a good way to do it?

And question.. how would I use the userID field to update oTime?