showing products after categories php - php

Question

I have the following markup which shows a list of categories and subcategories:
<table border="0" width="100%" cellspacing="0" cellpadding="2">
<tr class="dataTableHeadingRow">
<td class="dataTableHeadingContent"><?php echo TABLE_HEADING_PRODUCTS; ?></td>
<td class="dataTableHeadingContent" align="right"><?php echo TABLE_HEADING_TOTAL_WEIGHT; ?> </td>
</tr>
<?php
function category_list( $category_parent_id = 0 )
{
$sql = 'select cd.categories_name,c.categories_id, c.parent_id, c.sort_order from ' . TABLE_CATEGORIES . ' c, ' . TABLE_CATEGORIES_DESCRIPTION . ' cd where c.categories_id = cd.categories_id AND c.parent_id='.$category_parent_id;
$res = tep_db_query( $sql );
$cats = array();
while ( $cat = tep_db_fetch_array( $res ) )
{
$cats[] = $cat;
}
if (count($cats) == 0)
{
return '';
}
$list_items = array();
foreach ( $cats as $cat )
{
$list_items[] = '<tr class="dataTableRow"><td class="dataTableContent">';
if($category_parent_id != 0) $list_items[] = ' ';
if($category_parent_id == 0 )$list_items[] = '<b>';
$list_items[] = $cat['categories_name'];
if($category_parent_id == 0) $list_items[] = '</b>';
$list_items[] = '</td><td class="dataTableContent">';
$list_items[] = category_list( $cat['categories_id'] );
$list_items[] = '</td></tr>';
}
$list_items[] = '';
return implode( '', $list_items );
}
echo category_list();
?>
</table>
Each category is show in bold and the sub category is shown slightly indented to the right. I need to show the products available in each of the subcategory's. I tried adding the needed product fields to the sql query, but it didn't respond. The fields I need to add to search for the products are: products_id, products_name, these are from the table TABLE_PRODUCTS_DESCRIPTION, and to sort it their categories, there is another table called TABLE_PRODUCTS_TO_CATEGORIES, which has the fields products_id and categories_id.
How would I go about doing this?

Answer 1

It looks like you are using osCommerce or one of its forks and you want to display the amount of products for each category.
If you have only two levels of categories that's ok to do, if your category tree goes deeper, be warned that this is a real performance killer as building the category-tree in osCommerce is done, let's say, not really performance optimized, especially for complex tree structures.
The straight forward way is, to count the entries of the TABLE_PRODUCTS_TO_CATEGORIES table where the column categories_id holds the current category id:
$query = 'SELECT COUNT(*) FROM `'.TABLE_PRODUCTS_TO_CATEGORIES.'` WHERE `categories_id` = "'.$cat['categories_id'].'"';
Fetch the result and you have the count.
With this approach though you will only get the count of products directly in tnis category, not the count of products which reside in children categories.
You might also have a look on includes/boxes/categories.php as this is already built in in osC - the methods tep_show_category() and the herein called tep_count_products_in_category() might be usable for your purpose so no need to write it yourself.

Answer 2

I don't really like the from thing in the query for joining 2 tables. I have changed the query the way I prefer. You can change it to the from way if you wish.
$sql = 'select cd.categories_name,c.categories_id, c.parent_id, c.sort_order, pd.products_id, pd.products_name
from ' . TABLE_CATEGORIES . ' c
inner join ' . TABLE_CATEGORIES_DESCRIPTION . ' cd on c.categories_id = cd.categories_id
inner join '. TABLE_PRODUCTS_TO_CATEGORIES .' pc on pc.categories_id=c.categories_id
inner join ' . TABLE_PRODUCTS_DESCRIPTION . ' pd on pd.products_id=pc.products_id
where c.parent_id='.$category_parent_id;