Insert , Update , Delete -> Normalization & Code I

Working with tables and normalization

I have three tables

-----------
articles  
-----------
id  int(11)  auto_increment 
title varchar(100)


-----------
categories
----------
id  int(11) auto_increment 
title varchar(100)


-------------------
articles_categories
--------------------
articles_id  int(11)
categories_id int(11)

I want to save it according to normalization rule to achieve like this

articles_id  | categories_id
     1                1 
     1                2 
     1                3

How can I achieve with code igniter thanks. So far I had already tried like this

View | Create.php

<?php echo form_input('title','','id="title_input"'); ?><br>
Category
<?php 
    foreach ($categories as $c)
    {
        echo '<input type="checkbox" id="categories[]" name="categories[]" value="'.$c['id'].'">';
        echo $c['title'].'&nbsp';
        }
?>

    <?php
        echo form_submit('Submit',"Submit");
        echo form_close();
    ?>

Controller | articles.php

function insert()
{
    $this->articles_model->save();

}

Model | articles_model.php

Thomas Clayson already help with insert issue.

Saving articles and related categories according to normalization

function insert()
{
      $title = $this->input->post('title');
      $data = array('title' => $title);
      $this->db->insert('articles', $data);
      $article_id = $this->db->insert_id();
      $categories = $this->input->post('categories');
      $data = array();

      foreach($categories as $category_id)
      {
         $data[] = array(
          'articles_id' => $article_id,
          'categories_id' => $caregory_id
         );
      }
      $this->db->insert_batch('articles_categories', $data);
}

This is delete method

function delete($id)
{
     $this->db->delete('articles',array('id'=>$id));
}

I am now stuck with update method

function update($id)
{
    $id= $this->input->post('id');
    $title=$this->input->post('title');
    $categories = $_POST['categories'];

    $data=array(
        'title'=>$title,
    );

    $this->db->where('id', $id);
    $this->db->update('articles',$data);
    /*can update articles table now */


    /* here is the missing idea and what I had done so far*/
    $bb = array();
    foreach($categories as $categories_id )
    {
      $bb[] = array(
        'articles_id' => $id ,
    'categories_id' =>$categories_id 
      );                    
    }
    $this->db->update('articles_categories',$bb);
    /* end of missing idea */
}

   function select($id)
   {
     $query=$this->db->get_where('articles',array('slug'=>$slug));
     return $query->row_array();    

      /*missing idea to retieve categories */
   }

  function select_categories()

  {
     /*missing idea to retieve categories */
  }

Thanks for help

If you need to update articles_categories table with new values, there are some ways to do it. But my offer is deleting all relations by article id, and then insert them again. It's the best way to update relations table. To do that you can split you insert model;

function insert() {
    $title = $this->input->post('title');
    $data = array('title' => $title);
    $this->db->insert('articles', $data);
    $article_id = $this->db->insert_id();
    $categories = $this->input->post('categories');
    $this->insert_relations($article_id);
}

function insert_relations($article_id,$categories) {
    $data = array();
    foreach($categories as $category_id) {
        $data[] = array(
          'articles_id' => $article_id,
          'categories_id' => $caregory_id
        );
    }
    $this->db->insert_batch('articles_categories', $data);
}

and you need delete model for relations;

function delete_relations($articles_id) {
    $this->db->delete('articles_categories',array('id'=>$articles_id));
}

and you need to change your missing part like that;

/* here is the missing idea and what I had done so far*/
$this->delete_relations($id);
$this->insert_relations($id,$categories);
/* end of missing idea */