Hey,
The table you call a 'tying' table is also called a 'join' table. It is part of what it is known as a 'has and belongs to many' relationship. The good news is that Rails handles this very easily.
Let's take the Organizations - Addresses relationship. First you'll create your models and tables. You'll end up with these tables: organizations addresses
Then you need to create the join table:
addresses_organizations
Well you kinda need to write the code to add the address. It'd look something like this:
Let's say you've got an 'add address' form and it posts to an action that you want to add the address to an existing organization:
# Create and validate the new address address = Address.new(params[:address])
if address.save # Find the existing organization organization = Organization.find_by_id(params[:organization_id])
# Associate the address with this organization organization.addresses << address end
Obviously there's a lot more to getting it to work than that code, but I hope it demonstrates the concept.
Steve