public function getGroups()
{
    $result = $this->db->select('*')->from('tabulka')->execute();
    $pairs = $result->fetchPairs('id|name');
    $groups = array();
    foreach ($result->fetchAssoc('parent[]=id') as $parent => $ids) {
        $group = &$groups[$pairs[$parent]];
        foreach ($ids as $id) {
            $group[$id] = $pairs[$id];
        }
    }

    return $groups;
}