Hi all,

I am new on php/MySQL and now want to learning it to take more control of Zen Cart.

I have one questions not understand.

It is on MySQL table, such as products, inside it haven't the "p", for example products_id, products_model etc.

But general on the php coding, will see like that query

$products_query_raw = "select p.products_id, p.products_model, pd.products_name, p.products_quantity, p.products_type from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd where p.products_id = pd.products_id and pd.language_id='" . $_SESSION['languages_id'] . "' order by ".$sOrder." ";
$products = $db->Execute($products_query_raw);


Why add the addition p or pd. on the table's column name on the query? What do it doing?

Thank you very much. And anyone can give me a tutorial good for beginner like me?