Display categories in Codeigniter / PHP - php

Question

I am trying to display categories stored in my database:
http://dl.dropbox.com/u/16459516/Screen%20shot%202012-05-05%20at%2015.59.40.png
My idea was to get all data out of the database within my model and the reconstruct the array within my function:
function get_all_categories() {
$query = $this->db->query('SELECT * FROM categories');
//code to reconstruct my array like:
//foreach($query->result_array() as $row) {
//$categories[$row['niveau_1']] = array[]
//}
return $categories;
}
and output some array like:
[0] => Array
(
[niveau_1] => main category name
[niveau_2] => Array(
...children here and children of these childs
)
)
Does anyone know how to do this? Im stuck here and dont know how to create the array... i know how to display it in my views but getting them in the array seems hard for me.
Thanks in advance!

Answer 1

This is an idea:
foreach category (except level 4) check if it is present into the result array($c)
if it is not then create an array using a label the category's name
once controlle categories 2 and 3 you can insert the last one inside the generated array
$query = $this->db->query('SELECT * FROM categories');
$raw_categories = $query->result_array();
$c = array();
foreach($raw_categories AS $row)
{
if(!array_key_exists($row['niveau_2'],$c) && !empty($row['niveau_2']))
{
$c[$row['niveau_2']] = array();
}
if(!array_key_exists($row['niveau_3'],$c[$row['niveau_2']]) &&
!empty($row['niveau_3']))
{
$c[$row['niveau_2']]['niveau_3'] = array();
}
$c[$row['niveau_2']]['niveau_3'][] = $row['niveau_4'];
}
this is not tested but you can use it as an idea

Answer 2

I think your database is wrong. As I understand it's a "table of content" or similar (category, sub-category, sub-sub-category, etc.). "1. Visie, Beleid..." appears many-many times.
If I'd do I change the database:
table niveau_1
id_1 - primary key
title - string
table niveau_2
id_2 - primary key
id_1 - connect to niveau_1 (which niveau_1 is its 'parent')
title - string
table niveau_3
id_3 - primary key
id_2 - connect to niveau_2 (which niveau_2 is its parent)
title - string
In this case in your database will not duplicated elements and I think your desired query will be simplier:
SELECT
niveau_1.title AS title_1,
GROUP_CONCAT(niveau_2.title,"#") AS title_2,
GROUP_CONCAT(niveau_3.title,"#") AS title_3
FROM niveau_1
LEFT JOIN niveau_2 ON niveau_2.id_1=niveau_1.id_1
LEFT JOIN niveau_3 ON niveau_3.id_2=niveau_2.id_2
GROUP BY niveau_2.id_2
This query is only a half-solution, it isn't perfect for you but you can start from here.

Answer 3

// your model using activerecord
public function getCategories(){
$q = $this->db->get('categories');
if($q->num_rows > 0){
return $q->result();
}else{
return false;
}
}
//your controller
$this->load->model('category_model');
$data['results'] = $this->category_model->getCategories();
foreach($data['results'] as $c){
//iterate through categories, match them to points.
//match category_id in results with category_id in the other table results
//setup a multi dimensional array to build up what you need.
}