Hi everyone,
my apologies in advance since this is a rather trivial question, I
believe. But although I have the Pragmatic Programmers book laying on
my desk, I cant quite find a clear answer to the following question:
I have two tables - genes and organisms (therefore the models gene and
organism). Using the normal procedure, I created both models and a
controller (interface_controller) for my application.
The genes table holds information on genes, using ‘id’, ‘organism_id’,
and some other information. Obviously, an organism has many genes. I
thus created “belongs_to” in the gene model and “has_many” in the
organism model. genes.organism_id references to organisms.id in the
database.
The main page displays a list of organisms in the database, but what I
have failed to figure out thus far is the following:
How do I link an organism to all its genes (via organism_id). Meaning:
How do I pass the organism_id to a method in the controller and
thereby deciding which genes are then shown in a new page
(list_genes.rhtml). I hope that is kind of clear 
I believe I have
to write a method in the controller “def list-genes”, but I dont know
quite how.
Any advice would be greatly appreciated.
Cheers,
Marc