how can I access database in a helper function ?

[eluser]danmontgomery[/eluser]
get_instance() returns a copy of the codeigniter instance, you treat $CI like the controller object.

Code:

// In Controller
$this->load->model('my_model');
$this->my_model->my_function();

// Outside of controller
$CI =& get_instance();
$CI->load->model('my_model');
$CI->my_model->my_function();