Model concept question

Why re-invent the wheel?
Avenirer has developed a great MY_Model class:
https://github.com/avenirer/CodeIgniter-MY_Model

You must put the MY_Model.php file in the application/core folder.
Then, create your own model in application/models and extend the MY_Model class.
Like this:

PHP Code:

class User_model extends MY_Model {
   //... your code here
} 


With minimal setup, you can use the built-in functions of MY_Model.
Example:

PHP Code:

$this->load->model('user_model');
$this->user_model->where('city','London');
$this->user_model->order_by('address','ASC');
$users = $this->user_model->get_all(); 


It even works with method chaining:

PHP Code:

$users = $this->user_model->where('city','London')->order_by('address', 'ASC')->get_all(); 


Now, users is an array of objects with all the records that meet the 'where city = "London"' condition, in order of address. Easy as can be!