How to exclude nights from a TSQL query? - tsql

Question

I'm writing a TSQL query to find the next available datetime from a list of appointments. So far what I've managed to get working does find the gaps in a time query but I can't seem to find a great way to exclude nights (after 7pm lets say).
;WITH CTE
AS ( SELECT
ID,StartAptDate,EndAptDate,
RowNumber = ROW_NUMBER() OVER( ORDER BY StartAptDate ASC )
FROM Appointments WHERE StylistId = 1 AND StartAptDate > CAST( CONVERT( CHAR(8), GetDate(), 112) AS DATETIME)
)
SELECT FirstApptAvail = min( a.EndAptDate )
FROM CTE a
INNER JOIN CTE b
ON a.RowNumber = b.RowNumber - 1
WHERE datediff( minute, a.EndAptDate, b.StartAptDate) >= 15 AND ...
A little pseudo code for the ... would be something like this
(a.StartAptDate < GETDATE #7pm AND a.StartAptDate > GETDATE + 1 #8am)
The part I can't seem to get right is constructing the right side of each comparison. I need to exclude anything that might be returned between 7pm that night - 8am the next morning.
Thank you in advance

Answer 1

Thanks for the quick feedback - it looks like I was able to get the desired result using the BETWEEN statement mentioned in the comments above. I first made the startdate and enddate in question time specific (meaning the date part was 1900 / 01 / 01 so it didn't matter) This way I could use the time ONLY to compare with.
;WITH CTE
AS ( SELECT
ID,StartAptDate,EndAptDate,
RowNumber = ROW_NUMBER() OVER( ORDER BY StartAptDate ASC )
FROM Appointments WHERE StylistId = 1 AND StartAptDate > CAST( CONVERT( CHAR(8), GetDate() - 5, 112) AS DATETIME)
)
SELECT FirstApptAvail = min( a.EndAptDate )
FROM CTE a
INNER JOIN CTE b
ON a.RowNumber = b.RowNumber - 1
WHERE datediff( minute, a.EndAptDate, b.StartAptDate) >= 15 AND (CAST ( CONVERT( CHAR(8), a.StartAptDate, 108) AS DATETIME) BETWEEN '1900-01-01 07:59:59' AND '1900-01-01 18:59:59' AND CAST ( CONVERT( CHAR(8), a.EndAptDate, 108) AS DATETIME) BETWEEN '1900-01-01 07:59:59' AND '1900-01-01 18:59:59')