codeigniter pass variable from controller to model

simple issue I presume.

My controller is getting the if to display from the url using $this->uri->segment(3). This will always be a single value. I am putting this in an array to pass to the model with:

$customerid = array(
   'id' => $this->uri->segment(3)
);

The controller syntax is below:

function confirm_delete_customer()
{
            $data['title']="Confirm Customer Deletion";

            $customerid=array(
                'id'=>$this->uri->segment(3)
                );

            //query model to get data results for form
            $data=array();

            if($query=$this->model_master_data->get_customer_records_to_delete()){
                $data['records']=$query;


            $this->load->view("master_data/view_master_data_header",$data);
            $this->load->view("master_data/view_master_data_nav");
            $this->load->view("master_data/view_content_master_data_confirm_customer_deletion",$data);
            $this->load->view("master_data/view_master_data_footer");



}

I am then trying to access this array value and pass it to my model to process. If I hard code the array into the model it works as per below syntax:

Model - Manual Syntax is:

function get_customer_records_to_delete()
{
    $query = $this->db->get_where('customers', array('id'=>43));
    return $query->result();
}

if I try replace this with the array from my controller it fails with error: Undefined variable: customerid

idea of model that I want to get working:

function get_customer_records_to_delete()
{
    $query = $this->db->get_where('customers', $customerid);
    return $query->result();
}

I have a feeling it is something small. however is this the best way to get a single record from the database in order to output to a view?

Thanks in advance for the assistance.

The best way to do that is:

function confirm_delete_customer()
{
    $data=array();

    $data['title']="Confirm Customer Deletion";

    $customerId = $this->uri->segment(3);

    //Prevent SQL injections
    if(!is_numeric($customerId) || empty($customerId)) {
        show_error("Bad Request");
    }

    $query = $this->model_master_data->get_customer_records_to_delete($customerId);

    if ($query){
        $data['records']=$query;


        $this->load->view("master_data/view_master_data_header",$data);
        $this->load->view("master_data/view_master_data_nav");
        $this->load->view("master_data/view_content_master_data_confirm_customer_deletion",$data);
        $this->load->view("master_data/view_master_data_footer");

    }
}

and then you can simply call:

function get_customer_records_to_delete($customerId)
{
    $query = $this->db->get_where('customers', array('id'=>$customerId));
    return $query->result();
}

at your model.