Rails - Aug 2006 - More on n-way.

Hey, i found some n-way threads on the list, but I think they don`t
solve my case, or I didn`t understand how all of it works. I''m new to
Rails, so be pacient. :)

I''ll use an example of movie catalog, I''m realing doing a kind
of
movie catalog, for laerning rails, and I did this:

Models:
Movie, Actor, Director, Writer, Country, Language

The Movie model HABTM Actor, Director and Writer, and belongs_to
Country and Language

@Movie
id
name
country_id
language_id
year

Join tables:
movies_actors
movies_writers
movies_directors

Everything works! But I have a situation where I can have an *Actor*,
that is ALSO a *Director* or a *Writer too.
If I update some Actor information, I have to update it on the other
tables (Directors,Writers), if it''s there.

Solution ?

Using database, I solve like this.

@person
id
name
birth
...

@type
id
name

@movies_people_types
movie_id
person_id
type_id

In this way, I can have the same person working on a movie as a
Director AND as an Actor,
and I just update information in one place, the Person model.

How to put this on Rails ? If theres another way to get in the same
result, I`d appreciate suggetsiont.


PS. Sorry my English, I don''t know this tech english language, correct
me If I'' wrong.



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>
> In this way, I can have the same person working on a movie as a
> Director AND as an Actor,
> and I just update information in one place, the Person model.
>
> How to put this on Rails ? If theres another way to get in the same
> result, I`d appreciate suggetsiont.
>
>
Try something like this:

class Person
  has_many :roles
end

class Role
  belongs_to :person
  belongs_to :movie
end

class Actor < Role
end

class Director < Role
end

class Movie
  has_many :actors
  has_many :directors
end

Where the Role table is effectively the join table for the n:m relationship.

Max