Send only selected data .. many-to-many relationship table.

So, I want to create a many-to-many relationship table in my database for which I decided to create a function which is supposed to let me send data with not problem.

PHP Code:

           // Create many-to-many relationship
            $taxonomy_list = $this->Terms_model->get_list();

            foreach ( $taxonomy_list as $cat )
            {
                    //do insert here
                    $data = array(
                        'term_taxonomy_id'  => $this->db->insert_id(),
                        'term_id'           => $cat->term_id,
                        'type'              => 'category',
                    );
            }

            $this->Taxonomy_model->add($data);

            $relationship_list = $this->Taxonomy_model->get_list();

            $data = array();

            foreach ( $relationship_list as $rel )
            {
                    // Insert selected values
                    $data[] = array(
                        'post_id'           => $last_post_id,
                        'term_taxonomy_id'  => $rel->term_taxonomy_id,
                        'term_order'        => 0,
                    );
            }

//            $this->Relationship_model->add($data);
            $this->db->insert_batch('ci_terms_relationship', $data); 


So far it works great, the problem comes when selecting specific data (sometimes I just get to choose 1, sometimes 2,etc.).

The current function actually send all the values without taking into account that I just selected 1(maybe?).

Here are some pictures to clarify what I mean:



Second Pic:


third pic:

then in the post appear all three(or more depending on the number of categories that I have created).



I hope I could make myself clear.

Thanks in advance.

I do Front-End development most of the time 

Make a var_dump on categories and see what you are actually sending to your controller. If it's more then one (if only one selected) it's a javascript problem.