<?php
/*********************************************
* step 2
* - get_products_by_category($category_id)
**********************************************/
function get_products_by_category($category_id) {
    global $db;
    $query = "SELECT * FROM products
              WHERE products.categoryID = '$category_id'
              ORDER BY productID";
    $products = $db->query($query);
    return $products;
}

/***********************************************
* step 3
* delete_product($product_id)
***********************************************/
function delete_product($product_id) {
    global $db;
    $query = "DELETE FROM products
              WHERE productID = '$product_id'";
    $db->exec($query);
}
?>