El sábado 23 de junio de 2001  (13:52), Kristian Duske escribió:

> > The problem involves 2 tables, one of editors and one of categories, both
> > have unique ID numbers.  Each editor can have authority over an arbitrary
> > number of categories, and conversely, each category can have an arbitrary
> > number of editors.  So what is the best way to represent this in the DB?
> > (Which is PostgreSQL 7 BTW)
> 
> This is a so-called N:N relation, and this usually calls for a third table
> to store the cross-relations:
> 
> table editors
> id, name, email
> 
> table categories
> id, name
> 
> table ediors_categories
> editor (id of editor)
> category (id of category)

With index in the third table, How would it be ?

PRIMARY KEY (editor, category)

 or

KEY (editor),
KEY (category)

What's the better (more efficient and correct) ??

Regards
-- 
Antonio Mármol Albert ( [EMAIL PROTECTED] )
http://www.infurma.es

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