سؤال عن سكربت

قم بهذا الاستعلام

CREATE TABLE `useronline` (
  `timestamp` int(15) NOT NULL default '0',
  `ip` varchar(40) NOT NULL default '',
  `file` varchar(100) NOT NULL default '',
  PRIMARY KEY  (`timestamp`),
  KEY `ip` (`ip`),
  KEY `file` (`file`)
) TYPE=MyISAM;

انظر هذا الكود يفي بلغرض

<?php 
//fill in some basic info
$server = "localhost"; 
$db_user = ""; 
$db_pass = ""; 
$database = ""; 
$timeoutseconds = 300; 

//get the time
$timestamp = time(); 
$timeout = $timestamp-$timeoutseconds; 

//connect to database
mysql_connect($server, $db_user, $db_pass); 

//insert the values
$insert = mysql_db_query($database, "INSERT INTO useronline VALUES
('$timestamp','$REMOTE_ADDR','$PHP_SELF')"); 
if(!($insert)) { 
print "Useronline Insert Failed > "; 
} 

//delete values when they leave
$delete = mysql_db_query($database, "DELETE FROM useronline WHERE timestamp<$timeout"); 
if(!($delete)) { 
print "Useronline Delete Failed > "; 
} 

//grab the results
$result = mysql_db_query($database, "SELECT DISTINCT ip FROM useronline WHERE file='$PHP_SELF'"); 
if(!($result)) { 

print "Useronline Select Error > "; 
} 

//number of rows = the number of people online
$user = mysql_num_rows($result); 


//spit out the results
mysql_close(); 

?>