Advice on SQL and records

I'm teaching in computing. A question appeared in a trial paper recently and I'm trying to establish whether the suggested answer is correct.

The question was:

SELECT Students.Surname, Students.Name FROM Courses, Classes, StudentClasses, Students WHERE Courses.CourseID="10MA"

AND
    Courses.CourseID=Classes.CourseID
AND
    Classes.ClassID=StudentClasses.ClassID AND

StudentClasses.StudentID=STudents.StudentID

ORDER BY Students.Surname, Students.Name

Which of the tables is likely to contain the most records?

The suggested answer from Courses; Classes; StudentClassses and Students was:

StudentClasses

How would this be determined? Why wouldn't Students contain the most records?

Thanks

Fran Received on Sun Aug 21 2005 - 03:02:56 CDT