PHP - Sql Injection Prevention, Question.

Hi,

I'm trying to understand any how I can block all users trying to view my website through proxies. With the following code, what I have done is a quick version through php (with headers and ports) and not the firewall which isn't exactly the best way but still stops a lot of them.

<?php
$user_ip = $_SERVER['REMOTE_ADDR'];
$headers = array('CLIENT_IP','FORWARDED','FORWARDED_FOR','FORWARDED_FOR_IP','VIA','X_FORWARDED','X_FORWARDED_FOR','HTTP_CLIENT_IP','HTTP_FORWARDED','HTTP_FORWARDED_FOR','HTTP_FORWARDED_FOR_IP','HTTP_PROXY_CONNECTION','HTTP_VIA','HTTP_X_FORWARDED','HTTP_X_FORWARDED_FOR');
foreach ($headers as $header) {
	if (isset($_SERVER[$header])) {
		header("Location: /proxy-not-allowed/");
		die;
	}
}
$queryIP = "SELECT `user_ip_address` FROM `my_table` WHERE `user_ip_address` = :user_ip_address AND `user_blocked` = :user_blocked LIMIT 1";
$queryIP1 = $pdo->prepare($queryIP);
$queryIP1->execute(array(':user_ip_address' => $user_ip, ':user_blocked' => 'No'));
$queryIP2 = $queryIP1->rowCount();
if ($queryIP2 === 0) {
	$ports = array(80, 81, 553, 554, 1080, 3128, 4480, 6588, 8000, 8080);
	foreach ($ports as $port) {
		$connection = @fsockopen($user_ip, $port, $errno, $errstr, 0.1);
		if (is_resource($connection)) {
			header("Location: /proxy-not-allowed/");
			die;
		}
	}
}
?>

The headers script blocks any proxy sending those headers while the ports script blocks those using any assigned ports I add. I have tested this which seems to be good, though it won't block all proxies due to the assigned one I have. Is this the best way to go about blocking scripts if I don't have access to the firewall?

What I am trying to do is allow users to view my HTTPS website normally and block all proxies. Even if I have some users blocked, I do not want them to be cheeky and use a proxy or even register on my website through a proxy. I was thinking of just using the 443 port as my website is https (is that wise?). Any advice would be great.