ActiveRecord::Delegation leaks scope to inner queries on the same model about rails HOT 4 CLOSED

This is the expected behavior.

from rails.

Just to be clear #50396 might change that, but right now this is the expected behavior. If that PR changes it we will have to document it, but at the moment this isn't an issue.

from rails.

Edit: side note of an issue that popped up along with it:

It might be a good idea to document that passing a relation will result in immediate database access in connected_to

How about adding a sentence like:

Please be aware, that passing a relation in a connected_to block will immediately load the entire relation

to https://guides.rubyonrails.org/active_record_multiple_databases.html#using-manual-connection-switching?

from rails.

For anyone encountering this issue in the future, a workaround is to define the methods on ActiveRecord::Relation instead of on your model:

-class ApplicationRecord
-  def self.replica_find_each(...)
+class ActiveRecord::Relation
+  def replica_find_each(...)
     ActiveRecord::Base.connected_to(role: :replica) do
       find_each(...)
     end
   end
 end
+ApplicationRecord.delegate :replica_find_each, to: :all

This way, the method itself still uses the correct scope, but the scope does not leak into the method body or passed block.

from rails.