public function orderByASC(array $cols, $order_asc = true)
    {
        $this->order_asc = $order_asc;
        return $this->addOrderBy($cols);
    }
public function orderByASC(array $cols, $order_asc = true)
    {
        $this->order_asc = $order_asc;
        return $this->addOrderBy($cols);
    }
public function orderByASC ( array $ cols , $ order_asc = true ) { $ this -> order_asc = $ order_asc ; return $ this -> addOrderBy ( $ cols ) ; }
order by ASC OR DESC

@param array $cols
@param bool  $order_asc
@return self
order by ASC OR DESC