Question

belongs_to :keeper, :class_name => "Staff"
belongs_to "staff", :foreign_key => "keeper_id"

In my basic tests, these seem to be doing the exact same thing.
Are they indeed the same?
Is one better than the other?

Answer 1

The two statements define the same association. The difference is how the defined associations are referenced by the class defining those associations.

Calling belongs_to defines a whole whack of new instance methods for the calling class to handle the given relation. These new methods are named based on the first argument of belongs_to. As with most of the rest of Rails, ActiveRecord will use sensible defaults derived from the first argument to generate the methods that manage the association. Providing additional arguments to belongs_to just override those defaults.

In reality, they are identical in all but name. It all comes down to your personal preference. Would you rather refer to the association with @model.keeper or @model.staff?

Have a read through the belongs_to section of the Associations reference to get a better idea of the methods provided when a model belongs to another and how the options to belongs_to are used.