Base Codeigniter Model

base_m.php

<?php if (! defined('BASEPATH')) exit('No direct script access');

class Base_m extends CI_Model {

    protected $table_name;
    protected $pk_field;

    public function __construct() 
    {
        parent::__construct();
    }
    
    public function get_all()
    {
        $query = $this->db->get($this->table_name);
        
        if ($query->num_rows() > 0)
        {
            return $query->result();
        }
        else
        {
            return false;
        }
    }
    
    public function get($id)
    {
        $this->db->where($this->pk_field, $id);
        $result = $this->get_all();
        
        if (count($result) == 1)
        {
            return $result[0];
        }
        else
        {
            return false;
        }
    }
    
    public function create($data)
    {
        return $this->db->insert($this->table_name, $data);
    }
    
    public function update($pk, $data)
    {
        $this->db->where($this->pk_field, $pk);
        return $this->db->update($this->table_name, $data);
    }
    
    public function delete($key, $value = NULL)
    {
        if ($value == NULL)
        {
            return $this->db->delete($this->table_name, array($this->pk_field => $key));    
        }
        else
        {
            return $this->db->delete($this->table_name, array($key => $value));
        }
    }

}

implemented.php

<?php if (! defined('BASEPATH')) exit('No direct script access');

class Implemented extends Base_m {

    function __construct() 
    {
        $this->table_name = 'implemented_table';
        $this->pk_field = 'id';
        parent::__construct();
    }

    /***
     * Stack on more specific functions on top of the basic CRUD provided
     * by the base model easily
     */
    function get_by_user_id($user_id)
    {
        $this->db->where('user_id', $user_id);
        return parent::get_all();
    }

}

/***

$this->load->model('implemented');

$all_items = $this->implemented->get_all();

$all_items_by_user_id = $this->implemented->get_by_user_id($user_id);

etc...

*/