public function ref($mode = null)
{
if (!$this->owner->loaded()) {
throw $this->exception('Model must be loaded before traversing reference');
}
if ($mode == 'model') {
/** @type SQL_Model $m */
$m = $this->add($this->model_name);
return $m->addCondition($this->their_field, $this->owner->get($this->our_field));
}
$this->restoreConditions();
$this->model->unload();
return $this->model->addCondition($this->their_field, $this->owner->get($this->our_field));
}