alright guys, i have a script here where it works perfectly fine. expect it stores the user ID in a txt. document can help me with storing it in my database. thanks!

PHP Code:

<?php
 
$userIP= $_SERVER["REMOTE_ADDR"];
$file= "IPfile.txt";
 
if (file_exists($file)) {
   $fh = fopen($file,"r")
   or die ("Can't open file to read.");
   
   #  Read file line by line and put into array
   #
   while(!feof($fh))
   {
       $fileContents[] = fgets($fh);
   }
   fclose($fh);
 
   #  Check lines for IP match
   #
   foreach($fileContents as $line)
   {
            
       if($line = $userIP){
             $found = "True";
             echo "IP already exists.";
             break;
       }
   }
}
## If IP not found will append userIP to end of file.  
## If file doesn't exist it will create file and write IP to first line.
 
if ($found != "True"){
   echo "<p>IP not found.<p>";
   $fh = fopen($file ,"a")
    or die ("Can't open file to append.");
   fwrite($fh, "$userIP\n");
   fclose($fh);
   echo "<p>File Updated.<p>";
}
 
?>

I give you the logic, and let you try to code it.

1) gather the ip from the user
2) connect to the db
3) do a SELECT query with the gathered ip to chek if it exists
4) if it doesn't exists, make an INSERT query

And if your db have a UNIQUE INDEX on the field storing the ip, you can even avoid the check, as the db will refuse to insert a second time this ip.
A bit dirty, but it works.

It would be alot easier if you rewrote the db part of the script.