has_many :through with has_and_belongs_to_many in Rails

Question

In Rails - what is the effect of using has_many :through with has_and_belongs_to_many? Consider having two models - Posts and Tags which have a many-to-many relationship as indi

Answer 1

While I'm not sure of the exact effects of having a has_many :through on one side of a relationship and a has_and_belongs_to_many on the other side, I do know that the more correct way, would be to use a reversed has_many :through like so:

class Tag < ActiveRecord::Base
  has_many :posts_tag
  has_many :posts,  :through => posts_tag
end

Keeping the other relationships the same.