Sum Count Of Weekend Days In Overlapping Periods (MySQL)

- id (int)
- apartment_id (int)
- start (date)
- end (date)
- price (int)

$weekendDays = Helper::getNumberOfWeekendDays($checkIn, $checkOut);

            $query->leftJoin(\DB::raw('(
                SELECT
                    apartment_id,
                    SUM(DATEDIFF(LEAST("' . $checkOut . '", end), GREATEST("' . $checkIn . '", start)) * price) AS total_special_price,
                    SUM(DATEDIFF(LEAST("' . $checkOut . '", end), GREATEST("' . $checkIn . '", start))) AS special_days_count,
                    SUM(count_weekend_days(GREATEST("' . $checkIn . '", start), LEAST("' . $checkOut . '", end))) AS special_weekend_days
                FROM special_prices
                WHERE start < "' . $checkOut . '" AND end > "' . $checkIn . '"
                GROUP BY apartment_id
            ) AS sp'), 'sp.apartment_id', '=', 'a.id');

            $priceExpression = "ROUND(
                (pr." . $column . " * (" . $numberOfNights . " - COALESCE(sp.special_days_count, 0))
                + (COALESCE(a.weekend_extra_price, 0) * (" . $weekendDays . " - COALESCE(sp.special_weekend_days, 0)))
                + COALESCE(sp.total_special_price, 0)
                ) / " . $numberOfNights . "
            )";