Bukkit

<form method="get" action="register.php">
    <input type="text" name="player" placeholder="username">
    <input type="submit" value="Register">
</form>

<?php
    $host="localhost";
    $port=3306;
    $user="root";
    $pass="root";
    $db="minecraft";
    $table="whitelist";
    $player=$_GET['player'];
    $mysqli=new mysqli($host, $user, $pass, $db, $port);
    if($mysqli->query("INSERT INTO ".$table." VALUES ('".$player."')")){
        printf("Successful!\n");
    } else {
        printf("Error: %s\n", $mysqli->error);
    }
    $mysqli->close();
?>