Re: Question about "linking tables"

Kevin Porter wrote:
>
> Folks,
>
> I have a theory question regarding relational databases and linking tables:
>
> I saw an example where there were three tables, Books, Authors, and Categories,
> each with a sequential ID for a primary key.
>
> Now instead of having a field in Books that pointed to the foreign key in
> Authors, they had a linking table that had just the foreign keys listing the
> relationship between all the items in both tables. Then they had the same kind
> of table between Categories and Books, just with the foreign keys in it.
>
> So what is the advantage of having the linking table instead of the two foreign
> keys directly in the Books table? Is it easier for the users? Or is there
> database theory at work that I don't understand?
>
> Thanks - Bob
>
Consider that one author can have many (unknown number) books, one book many authors, and similarly categories and books Received on Sat May 19 2007 - 07:51:09 CEST