On Tue, Oct 15, 2002 at 09:07:36AM -0400, Ronan Heffernan wrote:
>
> >
> >>STUDENTS_CLASSES_TBL(_STUDENT_ID_, _CLASS_ID_, CLASS_PERIOD,GRADE_AVG)
> >>
> >
> >
> >The classes_tbl would really need the class_period field, not this one.
> >This is just a many-to-many table to link students to classes. And
> >grade_avg? Really needed?
>
>
> Yes and no. There should be another layer which defines a particular
> class, occurring at a certain period (and semester and schoolyear, so
> you don't have to clear your entire database each semester). The
> CLASSES_TBL is a good thing, acting as a course catalog. The name and
> description of the class may not change for many years (the same "AP
> English" class is offered every year). But you're right, there should
> be another layer above STUDENTS_CLASSES_TBL.
Ah, hadn't thought of that. You're right. If you want this to be more
than a snapshot, then the classes table might need a semester and year
(or semester_year) field.
Paul
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