I have GET[] input and would like to carry out their validation. The input data is always a number by. Schema. I want to make sure that the pass number and the appropriate amount - not to throw the sql query.

at this moment I am using the procedures

$cc = $_GET['cc'];
if ($cc=='') $cc='9012';$find=array("..", "/", "\\");
$replace=array("", "", "");
$cc=str_replace($find, $replace, $cc);

$eic = $_GET['eic']; 
.... ect.

// where f.ex. 9012 is an real existing data (in dbase) to generate sucure sql question

GET[] variable data schema

$_GET[$cc] - always 4 digits
$_GET[$eic] - always 4 digits
$_GET[$iy] - always 4 digits
$_GET[$ir] - always 1 digit

Can you show me a better way to secure my GET?