How to unscope default_scope in join/eager_load? - ruby-on-rails

Question

I have two models:
class User
default_scope -> { where(deleted_at: nil) }
end
class Order
belongs_to :user
end
And I want to get orders with deleted or not deleted users:
Order.joins(:user).merge(User.unscoped)
Order.joins(:user).merge(User.unscope(where: :deleted_at))
# SELECT "orders".* FROM "orders"
# INNER JOIN "users" ON "users"."id" = "orders"."user_id" AND "users"."deleted_at" IS NULL
# ORDER BY "orders"."id" DESC LIMIT 1
Order.eager_load(:user).merge(User.unscoped)
Order.eager_load(:user).merge(User.unscope(where: :deleted_at))
# SELECT "orders"."id" AS t0_r0, "orders"."user_id" AS t0_r1,
# "users"."id" AS t1_r0, "users"."deleted_at" AS t1_r1 FROM "orders"
# LEFT OUTER JOIN "users" ON "users"."id" = "orders"."user_id" AND "users"."deleted_at" IS NULL
# ORDER BY "orders"."id" DESC LIMIT 1
None of these work.
Every query adds "AND "users"."deleted_at" IS NULL" into join statement.
Nothing changes if I specify association scope:
class Order
belongs_to :user, -> { unscoped }
end
However includes works as expected:
Order.includes(:user).merge(User.unscoped).last
# SELECT "orders".* FROM "orders" ORDER BY "orders"."id" DESC LIMIT 1
# SELECT "users".* FROM "users" WHERE "users"."id" = 1054
How can I make rails to unscope association in a join?

Answer 1

You can try like this. It works in Rails >= 3
User.unscoped { Order.joins(:user) }

Answer 2

I solved this issue by writing join query manually. For your case it should look like:
Order.joins('INNER JOIN users ON users.id=orders.user_id')
Although Order.includes(:user).merge(User.unscoped)solution, that you found, looks a bit nicer, unless you really want to have only one query

Answer 3

You can define another association on same model to target specifically those deleted users:
This example works assuming you use act-as-paranoid to handle soft-deletion.
class Order
belongs_to :user
belongs_to :all_user, -> { with_deleted }, foreign_key: 'user_id'
end
Then choose your weapons:
Order.includes(:user).pluck(:email) # Only non soft-deleted emails
Order.includes(:all_user).pluck(:email) # All emails including where deleted_at is null
```