Need help to retrieve some datas between tables in one query [SOLVED]

[eluser]Ludovic-r[/eluser]
Hi !

I'm stuck with something that I can't fix and need your help, let me explain my configuration :

I have 3 TABLES :

TABLE #1 : called post
TABLE #2 : called categories
TABLE #3 : called post_categories

In my TABLE #1 I have some fields like id, text, title, date and so on
In my TABLE #2 I have id and category_name
In my TABLE #3 I link the post_id with the category_id

This is for the MySQL part.

Now I would retrieve my TABLE #1 entire informations and link my TABLE #2 category_name informations within the post
So to do that I've created TABLE #3 which make the link between post and category

The problem is that I can't retrieve my informations I don't know why :/

I've tried that :

Code:

$this->db->select('*');
        $this->db->from('post');
        $this->db->join('categories', 'post_categories.post_id = post_categories.category_id');
        $this->db->where('post.id', 'post_id');
        $this->db->order_by('rank', 'asc');
        
        $q = $this->db->get();
        
        return $q->result();

Oh and one another thing, If I need to DELETE once the category_name and the occurence in the TABLE #3 is it possible? I heard something like ON CASCADE but don't really know how to use it.

Any idea and help would be very very appreciated!

Thanks! (Sorry for my poor english)