Rails migration for has_and_belongs_to_many join table

Question

How do I do a script/generate migration to create a join table for a has_and_belongs_to_many relationship?

The application runs on Rails 2.

Answer 1

You should name the table the names of 2 models you want to connect by alphabetical order and put the two model id's in the table. Then connect each model to each other creating the associations in the model.

Here's an example:

# in migration
def self.up
  create_table 'categories_products', :id => false do |t|
    t.column :category_id, :integer
    t.column :product_id, :integer
  end
end

# models/product.rb
has_and_belongs_to_many :categories

# models/category.rb
has_and_belongs_to_many :products

But this is not very flexible and you should think about using has_many :through