SQL Server-Abfrage:Verwenden von JOIN zum Einschließen von NULL-Werten

Um NULL zurückzugeben oder zu erzeugen Werte müssen Sie LEFT JOIN verwenden s.

Ihre Abfrage sollte also etwa so aussehen:

SELECT 
     a.ReservationStayID AS 'Reservation Id'
    ,a.PMSConfirmationNumber AS 'PMS No'
    ,a.CreatedOn AS 'Date Created'
    ,a.ArrivalDate AS 'Date of Arrival'
    ,a.DepartureDate AS 'Date of Departure'
    ,a.TAProfileID AS 'TA Id'
    ,a.StatusCode AS 'Status'
    ,b.PropertyCode AS 'Hotel'
    ,c.NAME AS 'Travel Agency'
    ,c.CountryCode AS 'Market Code'
    ,d.CountryName AS 'Mkt'
FROM ReservationStay a
    INNER JOIN GuestStaySummary b ON a.ReservationStayID = b.ReservationStayID
    LEFT JOIN TravelAgency c ON a.TAProfileID = c.TravelAgencyID
    LEFT JOIN Market d ON c.CountryCode = d.CountryCode