Nid or Vid ?

Are nid and vid fields the same? The current ecommerce.mysql doesn't create a vid field only the nid field... Should I create the vid field that product.module is calling for? Or should I change the p.vid call to p.nid?

Here is the call... Line 44 of product.module
$result = pager_query(db_rewrite_sql('SELECT n.nid FROM {node} n INNER JOIN {ec_product} p ON n.vid = p.vid WHERE n.status = 1 ORDER BY n.sticky DESC, n.created DESC'), $rows * $columns, 0);

P.S. I added the field to the database and I no longer get the error. I just don't know if the module will function correctly.

Thanks,
Tom