phpmyadmin - Codeigniter get sum of goals a player has made -

i got database. mysql script of it. player can appear more in table want sum of goals player has made.

script:

create table if not exists `spelerswedstrijden` ( `id` int(5) not null auto_increment, `spelerid` int(2) not null, `wedstrijdid` int(5) not null, `goals` int(5) default null, `assisten` int(5) default null, `gelekaarten` int(5) default null, `rodekaarten` int(5) default null,  primary key (`id`)  ) 

my model code:

function getgoals($id) {      $this->db->where('spelerid', $id);     $this->db->from('spelerswedstrijden');     $goals = $this->db->select_sum('goals');;      return $goals; } 

using code gives me following error: object of class ci_db_mysql_driver not converted string ideas how can fix this? in advance

function getgoals($id)  {     $this->db->select('count(id) totalgoals');     $this->db->where('spelerid', $id);     $this->db->group_by('spelerid');     $goals = $this->db->get('goals');;     return $goals->row(); } 

in controller access this

$result = $this->mymodel->getgoals($id);  echo $result->totalgoals;