List products from nested categories

Question

I work hierarchical categories and products table for my project.

categories table structure:

ID - PARENT - TITLE

1 - 0 - Computer

1 - 0 - Phones

...

Categories table count of row 25107.

Product Table structure

ID - CAT - TITLE

1 - 1 - Product Name is here

I want current category and sub categories for list product.

echo $subcats = categoryChild(0);

Output is: 64198,18355,18356,95623,90504,6118,90505,6117,90506,90507,6119,6120,90508,90509,90510,90511,6103,90512,90513,90514,90515,142686,142688,142790,90516,6105,90517,90518,90519,90520,90521,91691,91692,92189,92190,92312,92313,95618,95619,95620,95621,95622,142684,142690,142692,142694,142696,142698,142700,3596

And I'm using this output MySQL IN statment. Finally generate this SQL query:

SELECT * FROM products WHERE cat IN (64198,18355,18356,95623,90504,6118,90505,6117,90506,90507,6119,6120,90508,90509,90510,90511,6103,90512,90513,90514,90515,142686,142688,142790,90516,6105,90517,90518,90519,90520,90521,91691,91692,92189,92190,92312,92313,95618,95619,95620,95621,95622,142684,142690,142692,142694,142696,142698,142700,3596)

This query is very slow... Please help me.

Answer 1

try this:

select p.id as id, p.title as title, c.title as category, c.id as catid
from products p JOIN
(select * from category where id = 1 OR parent = 1) c
on p.cat = c.id

see how it works on SQLFIDDLE

to list all hierarchy levels, write a code like this:

// return all childs of category with id $cat
function list_childs($cat){
    // run above query and change (select * from category where id = 1 OR parent = 1)
    // to (select * from category where parent = $cat) and return results
}

then in your code call this function for every category where you want to get children's

Answer 2

use this will allow you to fetch cat and sub cat for the parent_id argument. its nested and can be style with css and html.

`

     <ul class="" id="">

<?php
   function query($parent_id, $extension = null) { //function to run a query
   $query = mysql_query ( "SELECT * FROM exe_categories WHERE parent_id=$parent_id");
   return $query;
}
   function has_child($query) { //This function checks if the menus has childs or not
   $rows = mysql_num_rows ( $query );
   if ($rows > 0) {
    return true;
   } else {
    return false;
   }
}
function fetch_menu($query) {
   while ( $result = mysql_fetch_array ( $query ) ) {
     $id = $result ['id'];
     $title = $result ['title'];
     $menu_link = $result ['menu_link'];
     echo "<li><a href='{$menu_link}'><span>{$title}</span></a>";

        if (has_child ( query ( $id ) )) {
                    echo "<div>";
                    echo '<ul role="menu" class="fofc">';

                    fetch_menu ( query ( $id ) );
                    echo "</ul>";
                    echo "</div>";
        }

             echo "</li>";
      }
 }
   fetch_menu (query(1)); //call this function with 1 parent id

 ?>`