Question

I am using Zen Cart and currently am building a menu for ecommerce site. I have managed to figure out how to call all the categories but customer only wants the first 4 categories to be shown. There are over 20 categories right now and I only need the first 4 to show on the list. I am not sure the best, and easiest way to do this.

Is there a way to call a list

Example:

<ul>
   <li>Menu One</li>
   <li>Menu Two
      <ul>
         <li>Submenu One</li>
         <li>Submenu Two</li>
         <li>Submenu Three</li>
      </ul>
   </li>
   <li>Menu Three</li>
   <li>Menu Four</li>
   <li>Menu Five</li>
   <li>ect...</li>
</ul>

And then only show

<ul>
   <li>Menu One</li>
   <li>Menu Two
      <ul>
         <li>Submenu One</li>
         <li>Submenu Two</li>
         <li>Submenu Three</li>
      </ul>
   </li>
   <li>Menu Three</li>
   <li>Menu Four</li>
</ul>

I am hoping this is a simple solution!

Thanks!

Answer 1

Based on your reply, your query should be:

// Categories
$lid = (int) $_SESSION['languages_id']; 
$sql = "SELECT c.categories_id, cd.categories_name, c.parent_id "
     . "FROM " . TABLE_CATEGORIES . " c, " 
     . TABLE_CATEGORIES_DESCRIPTION . " cd "
     . "WHERE c.categories_id = cd.categories_id and c.categories_status = 1 " 
     . "AND cd.language_id = '{$lid}' "
     . "ORDER BY c.parent_id, c.sort_order, cd.categories_name "
     . "LIMIT 4"; 
$categories = $db->Execute($sql);

// Subcategories of the above
$lid = (int) $_SESSION['languages_id']; 
$sql = "SELECT c.categories_id, cd.categories_name, c.parent_id "
     . "FROM " . TABLE_CATEGORIES . " c, " 
     . TABLE_CATEGORIES_DESCRIPTION . " cd "
     . "WHERE c.categories_id IN ("
     .     "SELECT c.categories_id "
     .     "FROM " . TABLE_CATEGORIES . " c, " 
     .     TABLE_CATEGORIES_DESCRIPTION . " cd "
     .     "WHERE c.categories_id = cd.categories_id and c.categories_status = 1 " 
     .     "AND cd.language_id = '{$lid}' "
     .     "ORDER BY c.parent_id, c.sort_order, cd.categories_name "
     .     "LIMIT 4" 
     . "); 
$subcategories = $db->Execute($sql);

I don’t know the structure of your db but you can use the above to do a 2 step approach. The first one would be to get the first 4 categories. The second query is to get the subcategories of those 4 categories.

I am not so much in favor of subqueries – I avoid them as much as possible, so that in my view is not a very efficient solution. You could effectively traverse the first query and get the ids from there like so:

// Categories
$lid = (int) $_SESSION['languages_id']; 
$sql = "SELECT c.categories_id, cd.categories_name, c.parent_id "
     . "FROM " . TABLE_CATEGORIES . " c, " 
     . TABLE_CATEGORIES_DESCRIPTION . " cd "
     . "WHERE c.categories_id = cd.categories_id and c.categories_status = 1 " 
     . "AND cd.language_id = '{$lid}' "
     . "ORDER BY c.parent_id, c.sort_order, cd.categories_name "
     . "LIMIT 4"; 
$categories = $db->Execute($sql);

// Loop through the $categories and get the ids
$category_ids = array();
foreach ($categories as $category)
{
    $category_ids[] = $caregory->categories_id;
}
// Subcategories of the above
$lid = (int) $_SESSION['languages_id']; 
$sql = "SELECT c.categories_id, cd.categories_name, c.parent_id "
     . "FROM " . TABLE_CATEGORIES . " c, " 
     . TABLE_CATEGORIES_DESCRIPTION . " cd "
     . "WHERE c.categories_id IN (" . implode(",", $category_ids) . ")";
$subcategories = $db->Execute($sql);

The above in my view is much better than the subquery.

HTH

Credits to Lion