how can we use where condition if data is stored as implode

i want to get all the departments if location_id is 3. that means if location id 3 is used i need to get the department_names of cardiology and hair

My controller

public function get_location_departments()
{
   $d = $_POST['location'];
   $data['departments'] = $this->Hospital_model->get_location_departments($d);
   $this->load->view('frontend/ajax_get_departments',$data);
}

My model

public function get_location_departments($d)
{
  $this->db->where_in('location_id',$d);
  $query=$this->db->get('department')->result();
  return $query;
}

Hope this will help you :

You have to query first to get the department and get location_id into an array using explode

Your model get_location_departments method should be like this :

public function get_location_departments($d)
{
    if (! empty($d))
    {
        $query = $this->db->get('department');
        if ($query->num_rows() > 0 )
        {  
            foreach ($query->result() as $location)
            {
                $location_ids = explode(',',$location->location_id);
                if (in_array($d, $location_ids))
                {
                    $data[] = $location;
                }

            }
        }
    return $data;
    //print_r($data);  
    }
}