Incorrect counts and records returned for associated models

[davismattg]

Rails 5.1.6, Ruby 2.4.3, paranoia 2.4.1. MySQL 5.7

I have the following model setup:

class Parent < ApplicationRecord
    acts_as_paranoid
    has_many :children, dependent: :destroy
    accepts_nested_attributes_for :children, reject_if: :all_blank, allow_destroy: true
    ...
end
class Child < ApplicationRecord
    acts_as_paranoid
    belongs_to :parent
    ...
end

I'm seeing issues when trying to do get the associated children records for a given parent:

parent = Parent.find(1)

One record in the associated_children collection is soft-deleted, but the others are not.

parent.children.count 
=> 0 # returns 0 even though I can see 32 non-deleted associated_children records in the DB and Rails console

parent.children.with_deleted.count
=> 33

So there should be 32 records returned for associated_children, but instead I see:

parent.children.without_deleted.count
=> 0

parent.children.with_deleted.pluck(:deleted_at)
=> [nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, Thu, 03 Jan 2019 16:56:33 UTC +00:00, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil]

The kicker is this is only happening on 1 table of my database, and only on production. When I copy the production database locally the exact same queries as above work just fine for the same models that are failing on production.

[davismattg]

I've found that I can workaround the issue by changing my Child model to the following:

class Child < ApplicationRecord
    acts_as_paranoid without_default_scope: true
    default_scope {where(deleted_at: [nil, ''])}
    ...
end

Any idea why that would be?

[duybn-0885]

Do you use recursive delete ?