A puzzle about default_scope

rubyonrails-core
1

Hi, guys

I have a puzzle about default_scope.

Suppose I have two model:

  class User < ActiveRecord::Base
has_many :blogs
default_scope where(deleted_at: nil)
end
class Blog < ActiveRecord::Base
belongs_to :user
end

I want to produce sqlselect blogs.* from blogs inner join users on users.id = blogs.user_id and users.deleted_at is null

And the code Blog.joins(:user), which I think is good, produceselect blogs.* from blogs inner join users on users.id = blogs.user_id

The default_scope is not appended to the join condition, why?

To reach my goal, I must add conditions to belongs_to:

  class Blog < ActiveRecord::Base
belongs_to :user, conditions: "deleted_at is null"
end

Why not append default_scope to join condition directly as the doc said:

2

I came across this exact same behavior about three months ago.

If every other access to an AR class with a default scope honors that scope in the generated SQL, why not in a join situation?

Wes