generate

<?php
define('HOST','localhost');
define('PORT','3306');
define('USER','root');
define('PASS','');
define('DB','rolling');

$link = new mysqli(HOST,USER,PASS,DB);

function GenerateSession(){
    if ($link->connect_error) {
    die('Error : ('. $link->connect_errno .') '. $link->connect_error);
    }else{
        $permitted_chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
        $generate = substr(str_shuffle($permitted_chars), 0, 10);
        $statement = $link->prepare("SELECT * FROM code WHERE code = ?");
        $statement->bind_param("s", $code);
        $code = GenerateSession();
        $statement->execute();
        $total_row = $statement->fetch_row();
        if($total_row > 0 ){
            return GenerateSession();
        }else{
            return $generate;
            $state = $link->prepare("INSERT INTO code(code) VALUES(?)");
            $state->bind_param("s", $generate);
            $state->execute();
        }
        $statement->close()
    }
};

?>