Subcategory inside category in the Codeigniter framework - php

Question

I want to show subcategory inside the main category. My table looks like this. but when i print_r($cat_id) it returns only the last id of the category. How can I fix this? Here is my controller:
$data['categories'] = $this->courses_model->get_all_categories_for_courses();
foreach($data['categories'] as $ct){
$cat_id = $ct['id'];
}
$data['subcategories'] = $this->courses_model->get_all_subcategories_for_courses($cat_id);
$this->load->view('templates/header');
$this->load->view('courses/courses-grid-fullwidth', $data);
$this->load->view('templates/footer');
}
and here is my model:
public function get_all_categories_for_courses() {
$query = $this->db->get_where('categories', array('parent_id' => NULL));
return $query->result_array();
}
function get_all_subcategories_for_courses($cat_id) {
$query = $this->db->get_where('categories', array('parent_id' => $cat_id));
return $query->result_array();
}
and here is my view page:
<?php foreach($categories as $cat): ?>
<div class="col-md-3 col-sm-6 incat">
<h4>
<a href="#" class="catname"><i class="fa <?= $cat['icon']; ?>" aria-hidden="true"></i>
<?= $cat['name_rus']; ?></a>
</h4>
<ul>
<?php foreach($subcategories as $subcat): ?>
<li><?= $subcat['name_rus']; ?></li>
<?php endforeach; ?>
</ul>
</div>
<?php endforeach; ?>
Thanks in advance!

Answer 1

Or you can do this
<?php foreach($categories as $cat): ?>
<div class="col-md-3 col-sm-6 incat">
<h4>
<a href="<?= site_url('/courses/category/'.$cat['category_slug']); ?>" class="catname"><i class="fa <?= $cat['icon']; ?>" aria-hidden="true"></i>
<?= $cat['name_rus']; ?></a>
</h4>
<ul>
<?php
$query = $this->db->get_where('categories', array('parent_id' => $cat['id']));
?>
<?php foreach($query->result() as $subcat): ?>
<li><?= $subcat->name_rus; ?></li>
<?php endforeach; ?>
</ul>
</div>
<?php endforeach; ?>

Answer 2

As Ukasyah said in a comment on your question, you're overwriting the $cat_id value each time you loop through your categories.
What you will need to do is get an array populated with the IDs and use $this->db->where_in() to match an array rather than a single value.
Your controller will need to look more like this:
$data['categories'] = $this->courses_model->get_all_categories_for_courses();
$cat_ids = [];
foreach($data['categories'] as $ct){
$cat_ids[] = $ct['id'];
}
$data['subcategories'] = $this->courses_model->get_all_subcategories_for_courses($cat_ids);
$this->load->view('templates/header');
$this->load->view('courses/courses-grid-fullwidth', $data);
$this->load->view('templates/footer');
While you will need to change your model function to look like this:
function get_all_subcategories_for_courses($cat_ids) {
$query = $this->db->where_in('parent_id', $cat_ids)->get('categories');
return $query->result_array();
}
Best of luck.