PHP/MYSQL IP Check/Logger - php

Question

Ok, ive got a minecraft server and im making a voting script for it.
I need a way to check the users ip in a mySQL.
If it doesn't exist it will put the ip in the database, and it will remove it after 24 hours in the database.
If anyone could help me do this, it would be great, thanks

Answer 1

There are plenty of tutorials online on how to achieve this, thus I wont give you the code. Just a few hints to get you started.
In PHP, you can get the user's ip address from the $_SERVER superglobal
$ip = $_SERVER['REMOTE_ADDR'];
To check if it exists in your table
$query = sprintf("SELECT COUNT(*) FROM yourtable WHERE `ip` = '%s'", mysql_real_escape_string($ip));
If it does not exist, store it using the INSERT command along with a timestamp.
As for removing after 24 hours, you can set up a cron job that runs through the table every hour or so and removes all entries that have expired. However, it would be easier to not remove the entries. Instead, when a user votes, just check the timestamp of his last vote. If 24 hours have passed since the last vote, just update the timestamp.
Basically, the workflow would be:
1. Get users's IP address.
2. Does this IP exist in table?
2a. If no, let user vote, and enter his ip in the table along with the current time in the timestamp column
2b. If yes, get the timestamp of his last vote. Has it been 24 hours since his last vote?
2b.a. If yes, let user vote and update timestamp column with current time.
2b.b. If no, do not let user vote / reject his vote. Leave timestamp column unchanged.

Answer 2

The easiest way is to do the following
$ip = $_SERVER['REMOTE_ADDR'];
// Run cleanup for given IP
$result = mysql_query("SELECT * FROM table
WHERE `ip`='$ip' AND `timestamp` > NOW() - 24*3600");
if (mysql_num_rows($result)==0)
// there is no record within the last 24h, let insert a new one
{
mysql_query("INSERT INTO table SET `ip`='$ip', `timestamp` = NOW()");
echo "Thank you for your vote!";
}
else echo "You may vote only once in 24 hours";
// run total cleanup query from time to time
if (rand(1,5)<2) mysql_query("DELETE FROM table
WHERE `timestamp` < NOW() - 24*3600");
ps: If you have different votings, each of them should have different unique ID. and the MySQL table, which had before two columns ip and timestamp, should have one more column voteid, for example. In that case the code above will change to
// voteid should be somehow set to the id of the voting.
// for example by GET request
$voteid = intval($_GET['voteid']);
$ip = $_SERVER['REMOTE_ADDR'];
// Run cleanup for given IP
$result = mysql_query("SELECT * FROM table
WHERE `ip`='$ip' AND `voteid`='$voteid` AND `timestamp` > NOW() - 24*3600");
if (mysql_num_rows($result)==0)
// there is no record within the last 24h, let insert a new one
{
mysql_query("INSERT INTO table SET `ip`='$ip',
`voteid`='$voteid', `timestamp` = NOW()");
echo "Thank you for your vote!";
}
else echo "You may vote only once in 24 hours";
// run total cleanup query from time to time
if (rand(1,5)<2) mysql_query("DELETE FROM table
WHERE `timestamp` < NOW() - 24*3600");