How to get all the child and grandchild categories of a parent category in codeigniter?

categories, codeigniter, parent-child, php

Solution

You need recursivity. Create a function like this (assuming you use active records):

function getCategoriesByParentId($category_id) {
    $category_data = array();

    $category_query = $this->db->query("SELECT * FROM categories WHERE parent_category = '" . (int)$category_id . "'");

    foreach ($category_query->result() as $category) {
        $category_data[] = array(
            'category_id' => $category->category_id,
            'category_name' => $category->category_name,
            'category_alias' => $category->category_alias,
            'parent_category' => $category->parent_category
        );

        $children = getCategoriesByParentId($category->category_id);

        if ($children) {
            $category_data = array_merge($children, $category_data);
        }           
    }

    return $category_data;
}

and call it like this:

$all_categories = getCategoriesByParentId(0);

The output will be like this:

Array
(
    [0] => Array
        (
            [category_id] => 14
            [category_name] => s3
            [category_alias] => s3
            [parent_category] => 13
        )

    [1] => Array
        (
            [category_id] => 13
            [category_name] => Samsung
            [category_alias] => samsung
            [parent_category] => 12
        )

    [2] => Array
        (
            [category_id] => 12
            [category_name] => Phone
            [category_alias] => phone
            [parent_category] => 0
        )

)

For more info, this was taken from `OpenCart 1.5.4`, class `ModelCatalogCategory` under `catalog\model\catalog\category.php`.

Problem

Original source