class database
{
    private $conn;
    private $db_name = 'profil_penduduk';
    private $db_user = 'root';
    private $db_pass = '';
    private $db_host = 'localhost';

    public function connect()
    {

        $this->conn = null;
        try
        {
            $this->conn = new PDO("mysql:host=$this->db_host;dbname=$this->db_name", $this->db_user, $this->db_pass);
            $this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
        catch(PDOException $exception)
        {
            echo "Connection error: " . $exception->getMessage();
        }

        return $this->conn;
    }
}

class admin
{
    private $conn;

    function __construct()
    {
        # code...
        $database = new database();
        $db = $database->connect();
        $this->conn = $db;
    }

    public function runQuery($sql)
    {
        # code...
        $stmt = $this->conn->prepare($sql);
        return $stmt;
    }
}

$auth_admin = new admin();


$admin_id = $_SESSION['admin_session'];

$stmt = $auth_admin->runQuery("SELECT * FROM admin WHERE admin_id=:admin_id");
$stmt->execute(array(":admin_id"=>$admin_id));

$adminRow=$stmt->fetch(PDO::FETCH_ASSOC);

"SELECT * FROM admin WHERE admin_id=:admin_id"