Rails Ruby on Rails

We have normal one_to_many association

  class User < ActiveRecord::Base
    has_many :movies
  end
  
  class Movie < ActiveRecord::Base
    belongs_to :user
  end

Let's create user and some movies

user = User.create(:name => "user")
=> #<User id: 1, name: "user", movies_count: nil>
user.movies << [Movie.new(:name => "Titanic"), Movie.new(:name => "Matrix")]
=> [#<Movie id: 1, name: "Titanic", subject_type: "User", subject_id: 1>, #<Movie id: 2, name: "Matrix", subject_type: "User", subject_id: 1>]
titanic = @user.movies[0]
=> #<Movie id: 1, name: "Titanic", subject_type: "User", subject_id: 1>

Everything is ok now:

user.movies
=> [#<Movie id: 1, name: "Titanic", subject_type: "User", subject_id: 1>, #<Movie id: 2, name: "Matrix", subject_type: "User", subject_id: 1>]

After destroy

user.movies.destroy(titanic)
=> [#<Movie id: 1, name: "Titanic", subject_type: "User", subject_id: 1>, #<Movie id: 2, name: "Matrix", subject_type: "User", subject_id: 1>]
user.movies
=> [#<Movie id: 1, name: "Titanic", subject_type: "User", subject_id: 1>, #<Movie id: 2, name: "Matrix", subject_type: "User", subject_id: 1>]

It is not ok. Array contains destroyed movie. You need to reload object(make new database query)

user.reload.movies
=> [#<Movie id: 2, name: "Matrix", subject_type: "User", subject_id: 1>]
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