Get total amount of days for the month between 2 dates grouped by month

Question

I have a booking system for hotel rooms, sometimes there are reservations that start in one month and finish in another month. For example 22 April 2019 to 07 May 2019.

I need to be able to see how many days the room was booked in April.

Can't figure out how to reduce the overlapping days in the next month.

So if I have those bookings:

07/Apr/2019 to 12/Apr/2019
22/Apr/2019 to 07/May/2019
29/May/2019 to 03/June/2019

It should give me:

April 2019: 13 Days May 2019: 10 Days June 2019: 3 Days

I tried using DATEDIFF and SUM but it adds MAY Dates also.

$sql = "SELECT 
id, SUM(DATEDIFF(booking_to, transaction_date)) + 1 AS occup,
COALESCE(COUNT(id), 0) AS `transactions`,
COALESCE(SUM(revenue), 0) AS `revenue`
FROM transactions
WHERE property_id = $pvid
AND MONTH(transaction_date) = $tranmonth 
AND YEAR(transaction_date) = $tranyear
group by property_id"; 

Currently it is giving me 20 Days which is incorrect.

Is it possible to the amount of days booked only for April?

Answer 1

what you probably need is the last day of the month and diff it after

SELECT LAST_DAY(NOW());

edit:

     select now() as now, timestampdiff(day, now(), last_day(now())) as diff;
+---------------------+------+
| now                 | diff |
+---------------------+------+
| 2019-05-04 05:48:43 |   26 |
+---------------------+------+
1 row in set (0.00 sec)