Base::prepareElementQueryFields

protected function prepareElementQueryFields()
{
	$result = $this->prepareQueryFields($this->selectFields, $this->filterFields, $this->sortFields);
	$this->selectFields = $result['SELECT'];
	$this->filterFields = $result['FILTER'];
	$this->sortFields = $result['ORDER'];
	if (!empty($this->globalFilter))
	{
		$result = $this->prepareQueryFields([], $this->globalFilter, []);
		$this->globalFilter = $result['FILTER'];
	}
	unset($result);
}