controller :
function insert_brand() {
	if (empty($this->input->post())) {
	$content_header = new DVORE_admin_header_obj();
	$content_header->save_button = new stdClass();
	$content_header->save_button->target_form = "#add-brand";
	$page_data["content_header"] = $content_header;
	$page_data["page_name"] = "insert_test_data/brand";
	$this->load->view('admin', 'site/index', $page_data);
	}else{
	$post = $this->input->post();
	$this->{$this->model_name}->insert_test_brand($post);
	redirect(dvore_base_url("admin/brands/all"));
	}
}

model :
function insert_test_brand($post){
    $nb_brand = $post["nb_brand"];
    if(is_numeric($nb_brand)){
        for($i = 0; $i < $nb_brand; $i++){
            $insert = [];
            $insert["name"] = "brand" . $i . "_test";
            $insert["user_added"] = 999999;
            $insert["date_added"] = date("Y-m-d H:i:s");
            $this->db->insert("VORE_SHOP_brands", $insert);
        }
    }
}