static $types;

$type_id = mysqli_fetch_field_direct($result, $field_offset)->type;

if (!isset($types)) {

$types = array();

$constants = get_defined_constants(true);

foreach ($constants['mysqli'] as $c => $n) if (preg_match('/^MYSQLI_TYPE_(.*)/', $c, $m)) $types[$n] = $m[1];

}

return array_key_exists($type_id, $types) ? $types[$type_id] : NULL;