[Dbix-class] Newbie - database structure

[Dermot]

>
> >There is a section about making 3 tables with SQLite3; books, authors and
> book_authors. The last table is described as
> >'book_authors' is a many-to-many join table between books & authors'
> >
> >My query is: Is this the "best practise" or an over-simplification for us
> newbies? Would you normally create a table for >joins to show many to many
> relationships? I would have though that you could use SQL statements to
> retreive that rather >than create a table of it.
>
>
> To answer your question, yes, you need a join table. Each record in it
> expresses a relationship between a record in table A and a record in table
> B.
>
> I'd recommend working through an SQL book that explains SQL concepts in
> more
> detail as that really is a prerequisite for using a database or DBIC
> effectively.
> E.g. http://tinyurl.com/ywdxfu
>
> I am unsettled by this. I went and re-read chapter 4 of the book I do have
(learning MYSQL) on database design and modelling. I still can't see the
value in creating a separate table for a join.

If you have a 1:N table of authors and a table of books with the author ID
as a foreign key, surely that all you need to create any join you might
want. I know sqlite3 doesn't understand foreign keys but DBIC can create
them for you. Isn't that where the relationship is established?

Sorry to drone on but if I am told that this is standard practise, I can see
a proliferation of tables being created for every relationship that might
exist in the application I am trying to create.

Thoughts?
Dp.
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