ActiveRecord class association

Question

Let's pretend that we have two tables, Posts and Categories, that have a many to one relationship, one category to many posts. Which would be the best way to go about defining that in the class definitions?

1. Just Category { has_many Posts }
2. Just Post { belongs_to Category }
3. Both Category { has_many Posts } AND Post { belongs_to Category }

Answer 1

As you want to be able to do something like myCategory->Posts if you have a category, but also myPost->categories, you want to define both relations.