Mysql insert not working properly

[eluser]ppwalks[/eluser]
Think may have found an easier way to get the values into db, but stumbled across another problem, I have used the batch_update method to insert the arrays but I cannot think of a way to add an identifier to the table. here is the bit of code:

Code:

$data = array(
    $product, $cat_id
  );
      $this->db->insert_batch('product_category', $data);

And this produces:

Unknown column '0' in 'field list'

INSERT INTO `product_category` (`0`, `1`, `2`) VALUES ('297','297','297'), ('1','4','6')

So how can I change the table selection, this is seriously driving me mad now!

thanks in advance....