proper format for this database table

[mensanator at aol.com]

John Salerno wrote:
> Carsten Haese wrote:
>
> >>> [id] [university] [yearStart] [yearEnd] [degreeEarned]
> >>> 1     U of I       1971        1975      BS
> >>> 1     U of I       1975        1976      MS
> >>> 1     U of I       1976        1977      PhD
> >>>
> >> Thanks guys. I do plan to have an id entry for each person as well, I
> >> just forgot to mention that. But since it's a primary key, I didn't know
> >> I could list it more than once. Or does primary key not necessarily mean
> >> unique?
> >
> > Primary key *does* mean unique in the table that defines it. However, if
> > you take a primary key ID from one table and store it in a different
> > table, that's a foreign key. There are no inherent uniqueness
> > constraints on a foreign key.
> >
>
> So in the example above, isn't that using the same primary key multiple
> times in the same table?

Actually, the [id] in the example was intended to be the
foreign key, I didn't specify an id for the degree records
themselves. A more typical example would be

[Eid] [Sid] [university] [yearStart] [yearEnd] [degreeEarned]
5      1     U of I       1971        1975      BS
6      1     U of I       1975        1976      MS
7      1     U of I       1976        1977      PhD

where [Eid] is the primary key of the Education table and
[Sid] is the foreign key from the Student table so that the
single student record (1) links to three education records
(5,6,7).