<?php  kategoriYaz(); ?>
<?php
function kategoriYaz($kid = NULL) {
db = new mysqli('sunucu', 'kullanici', 'sifre', 'vt_adi');
$sql  = "SELECT * FROM kategori WHERE ".($kid ? "kid = ".$kid : "ISNULL(kid)")."  ORDER BY id desc";
  $rs = $db->query($sql );
print $kid  . " -> " . $sql;
    if($rs->num_rows) {
      while($row = $rs->fetch_assoc()) {
        echo $row['isim'];
        kategoriYaz($row['id']);
      }
    }
  }
?>