How to split revenue by day between two months - sql

Question

We have group bookings held in our system as blocks. I can get total revenue held on the block per group by arrival and departure date.
The problem is that the revenue per group is the total revenue shown is that generated during the whole period the bedrooms are blocked for. This would be ok if each group arrived and left in the same month. However, there are groups that arrive in a month and leave on the following month.
I need to split the revenue for these groups by month. So, for example if a group arrives on 28/06 and leaves on 3/07, I need to know how much of that revenue is generated in June (3 nights) and how much in July (2 nights).
The query below is correct but will give me total revenue based on EndDate (check out date), so revenue will all go on the month the group departs.
I am also comparing same time last year
SELECT DAILYREV = ProjectedRevenueAccomNett/ DATEDIFF(Day,BeginDate, EndDate), DATEDIFF(DAY,BeginDate, EndDate) AS StayNights, Year(BeginDate) ArrivalYear, GroupRef, GAStatus, SourceSiteId, BeginDate, EndDate, CreatedTimestamp, DefMarketSegmentCode,ProjectedRevenueAccomNett, ProjectedRevenueFBNett
From SyncGroupRoomBlockHeaders
WHERE CreatedTimestamp <= '2019-03-28'
AND BeginDate BETWEEN '2019-03-28' AND '2019-12-31'
or
CreatedTimestamp <= '2018-03-28'
AND BeginDate BETWEEN '2018-03-28' AND '2018-12-31'
Order By YEAR (BeginDate)

Answer 1

Your question can be interpreted in different ways. I think the following query will point you in the right direction. Maybe you can use this approach and edit it to your own needs:
USE TEMPDB
IF OBJECT_ID ('TEMPDB..Bookings') IS NOT NULL DROP TABLE Bookings;
CREATE TABLE Bookings (ID INT,
StartDate DATE,
EndDate Date,
Total DECIMAL (8,2),
NumberDays AS DATEDIFF (DAY, StartDate, EndDate))
INSERT INTO Bookings VALUES (1, '20190130', '20190202', 210.15)
IF OBJECT_ID ('TEMPDB..BookingNew') IS NOT NULL DROP TABLE BookingNew;
SELECT *, Total / NumberDays AS PricePerDay
INTO BookingNew
FROM Bookings
DECLARE #StartDate DATE
DECLARE #EndDate DATE
SET #StartDate = '2000-01-01' -- << user input >>
SET #EndDate = '2040-12-31' -- << user input >>
IF OBJECT_ID ('TEMPDB..#Date') IS NOT NULL DROP TABLE #Date
IF OBJECT_ID ('TEMPDB..#Date') IS NULL CREATE TABLE #Date (Date DATE)
INSERT INTO #Date VALUES (#StartDate)
WHILE #StartDate < #EndDate
BEGIN
INSERT INTO #Date
SELECT DATEADD (DD, 1, #StartDate) AS Date
SET #StartDate = DATEADD (DD, 1, #StartDate)
END
SELECT *
FROM #Date AS D
INNER JOIN BookingNew AS B ON D.Date BETWEEN B.StartDate AND B.EndDate