I agree. There is no special tricks to use multiple tables with outer joins other than ensuring you avoid ambiguous joins
Here's another one aggregate query of mine. This time with 4 tables all with outer joins
Code:
SELECT DISTINCT Subjects.FacultyID, Timetable.RoomID, Count(Timetable.RoomID) AS Lessons
FROM ((Classes LEFT JOIN Subjects ON Classes.SubjectID = Subjects.SubjectID)
RIGHT JOIN Timetable ON Classes.ClassID = Timetable.ClassID)
LEFT JOIN Faculties ON Subjects.FacultyID = Faculties.FacultyID
WHERE (((Classes.Offsite)=False))
GROUP BY Subjects.FacultyID, Timetable.RoomID
HAVING (((Subjects.FacultyID)<>'') AND ((Timetable.RoomID)<>'' And (Timetable.RoomID)<>'-'))
ORDER BY Subjects.FacultyID, Timetable.RoomID;
If you're finding this process difficult I suggest you try creating it first as a standard select query and modify as necessary to ensure it gives the correct records.
Then change it to an aggregate query