<?php

# See application/core/MY_Model for this parent model
class Cpm_model extends Crud_model
{

  public function __construct()
  {
    parent::__construct();
    $this->table = 'cpm';

  }

  public function getAllByType($id, $type)
  {
    $this->db->where('fixture_id', $id);
    $this->db->where('coverage_type', $type);
    return $this->db->get($this->table)->result();
  }

}

<?php

# See application/core/MY_Model for this parent model
class Cpm_model extends Crud_model
{

  public function __construct()
  {
    parent::__construct();
    $this->table = 'cpm';

  }

  public function getAllByType($id, $type)
  {
    $this->db->where('fixture_id', $id);
    $this->db->where('coverage_type', $type);
    return $this->formatNull($this->db->get($this->table)->result());
  }

  public function formatNull($res)
  {
    foreach($res as $key => $val){
      if($res[$key]->icon_type == null || $res[$key]->icon_type == ''){
        $res[$key]->icon_type = 'N/A';
      }
    }
    return $res;
  }
}

Add format null for CPM
Add format null for CPM
