Finding How Many Users Are On Your Site With PHP - Displaying the number of users

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At this point some of you may be questioning the method that we’re using to grab the number of users from the database, however, coming from an ASP background, I've used what I know about ASP to accomplish this, and as far as I and many other people are concerned, the statelessness of HTTP sucks. If there was some way to tell PHP when a session starts and ends, then this task would be made so much easier, but because we don’t we're making the best of what we have: a stateless protocol, a database, and the users IP address.

Anyhow, create a new file called usersonline.php and enter the following code into it:

<?php

include("dbinfo.php");

// Set length of session to twenty minutes
define("SESSION_LENGTH", 20);

$sConn = @mysql_connect($dbServer, $dbUser, $dbPass)
or die("Couldnt connect to database");

$dbConn = @mysql_select_db($dbName, $sConn)
or die("Couldnt select database $dbName");

$timeMax = time() - (60 * SESSION_LENGTH);

$result = mysql_query("select count(*) from usersOnline where unix_timestamp(dateAdded) >= '$timeMax'");

$usersOnline = mysql_result($result, 0, 0);

echo "There " . ($usersOnline != 1 ? "are" : "is") . " $usersOnline user" . ($usersOnline != 1 ? "s" : "") . " online. ";

if($usersOnline == 0)
echo "It's not too busy at the moment.";
else if($usersOnline >= 1 && $usersOnline <= 10)
echo "Users are starting to build up.";
else if($usersOnline >= 11 && $usersOnline <= 30)
echo "Wow, it's getting packed in here!";
else if($usersOnline >= 31 && $usersOnline <= 50)
echo "The servers are running on full speed ahead!";
else
echo "Wow!!! This site is packed!";

?>

The first eight lines or so are exactly the same as adduser.php, i.e. we're still connecting to the database, defining SESSION_LENGTH, etc. After that we get a count of all users who a record was added for in the last twenty minutes or less:

$result = mysql_query("select count(*) from usersOnline where unix_timestamp(dateAdded) >= '$timeMax'");

We then use mysql_result to get the number of users into $usersOnline and print out how many users are online. We set the syntax of the statement so that if there is 1 user online then "There is 1 user online" will be printed instead of "There are 1 users online":

$usersOnline = mysql_result($result, 0, 0);

echo "There " . ($usersOnline != 1 ? "are" : "is") . " $usersOnline user" . ($usersOnline != 1 ? "s" : "") . " online. ";

Lastly, we output a comment, depending on how many users are online:

if($usersOnline == 0)
echo "It's not too busy at the moment.";
else if($usersOnline >= 1 && $usersOnline <= 10)
echo "Users are starting to build up.";
else if($usersOnline >= 11 && $usersOnline <= 30)
echo "Wow, it's getting packed in here!";
else if($usersOnline >= 31 && $usersOnline <= 50)
echo "The servers are running on full speed ahead!";
else
echo "Wow!!! This site is packed!";

If you're feeling creative then you should change these messages to maybe include some humor or make them relate to your site somehow.

Once I got a couple of work colleagues to visit my page, here's how it looked:



To use our scripts, simple include adduser.php at the top of every page on your site like this:

<?php include("adduser.php"); ?>

Then, wherever you want to display how many users are online, just include usersonline.php, like this:

<?php include("usersonline.php"); ?>

Of course, the support material for this article contains all of our scripts as well as the MySQL code to re-create our database and table. You can download it on the next page.

Next: Conclusion >>
 

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