default_scope and associations

Question

Suppose I have a Post model, and a Comment model. Using a common pattern, Post has_many Comments.

If Comment has a default_scope set:

default_scope where("deleted_at IS NULL")

How do I easily retrieve ALL comments on a post, regardless of scope? This produces invalid results:

Post.first.comments.unscoped

Which generates the following queries:

SELECT * FROM posts LIMIT 1;
SELECT * FROM comments;

Instead of:

SELECT * FROM posts LIMIT 1;
SELECT * FROM comments WHERE post_id = 1;

Running:

Post.first.comments

Produces:

SELECT * FROM posts LIMIT 1;
SELECT * FROM comments WHERE deleted_at IS NULL AND post_id = 1;

I understand the basic principle of unscoped removing all existing scopes, but shouldn't it be aware and to keep the association scope?

What is the best way to pull ALL comments?

Answer 1

For some strange reasons,

Comment.unscoped { Post.last.comments }

includes the default_scope of Comment,

however,

Comment.unscoped { Post.last.comments.to_a }
Comment.unscoped { Post.last.comments.order }

do not include the default_scope of Comment.

I experienced this in a rails console session with Rails 3.2.3.