Hello all...

My class diagram...

Author
name
compositions

Composition
publisher
authors

How can I list Authors to associate him to a composition???
I explain: I would like to list the authors that yet aren't authors of a composition.

So, how can I write a query that list all authors, except the authors of the a composition.

Something like this query in SQL:
SELECT DISTINCT a.name
FROM author AS a
INNER JOIN authors_compositions AS ac ON a.idAuthor = ac.idAuthor
WHERE ac.idComposition <> ?


Can I make me clear, with my poor english? :-)

Sorry...

Alex.