如何使用 ActiveRecord::Base.update 当default_scope排除记录时

Question

当我的默认范围不包括要更新的记录时，如何在对象上使用更新？

默认范围

class Player < ActiveRecord::Base
  default_scope { where(imported_with_errors: false) }
end

播放器控制器

respond_to do |format|
   if @player.update(player_params)    # errors out at this line...
     # ...
   else
     # ...
   end
end

错误

Couldn't find Player with 'id'=34839 [WHERE [players].[imported_with_errors] = 0]

set_player

@player = Player.unscoped.friendly.find(params[:id])

堆栈跟踪

activerecord (4.2.0) lib/active_record/relation/finder_methods.rb:336:in `raise_record_not_found_exception!'
activerecord (4.2.0) lib/active_record/relation/finder_methods.rb:456:in `find_one'
activerecord (4.2.0) lib/active_record/relation/finder_methods.rb:435:in `find_with_ids'
activerecord (4.2.0) lib/active_record/relation/finder_methods.rb:71:in `find'
app/controllers/players_controller.rb:106:in `set_player'
activesupport (4.2.0) lib/active_support/callbacks.rb:427:in `block in make_lambda'
activesupport (4.2.0) lib/active_support/callbacks.rb:145:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:145:in `block in halting_and_conditional'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:151:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:151:in `block in halting_and_conditional'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:308:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:308:in `block (2 levels) in halting'
rails-observers (0.1.2) lib/rails/observers/action_controller/caching/sweeping.rb:73:in `around'
activesupport (4.2.0) lib/active_support/callbacks.rb:450:in `public_send'
activesupport (4.2.0) lib/active_support/callbacks.rb:450:in `block in make_lambda'
activesupport (4.2.0) lib/active_support/callbacks.rb:307:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:307:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:151:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:151:in `block in halting_and_conditional'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_process_action_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.2.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.2.0) lib/abstract_controller/base.rb:137:in `process'
actionview (4.2.0) lib/action_view/rendering.rb:30:in `process'
actionpack (4.2.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal.rb:236:in `block in action'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:42:in `serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:43:in `block in serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `each'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `serve'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:802:in `call'
rack (1.6.4) lib/rack/etag.rb:24:in `call'
rack (1.6.4) lib/rack/conditionalget.rb:38:in `call'
rack (1.6.4) lib/rack/head.rb:13:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/flash.rb:260:in `call'
rack (1.6.4) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.6.4) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/cookies.rb:560:in `call'
activerecord (4.2.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.2.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:647:in `call'
activerecord (4.2.0) lib/active_record/migration.rb:378:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_call_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
web-console (2.2.1) lib/web_console/middleware.rb:31:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/static.rb:113:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.0) lib/rails/engine.rb:518:in `call'
railties (4.2.0) lib/rails/application.rb:164:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
/home/daveomcd/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
/home/daveomcd/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
/home/daveomcd/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'

Answer 1

它会

在那之前，你会得到@player，但我认为rails不会评估它，直到它需要。 要访问它，您只需调用 unscoped。

@player = Player.unscoped.find(params[:id)

Answer 2

Player.unscoped.find(id) 

返回

模型的范围，而不返回以前设置的范围。

class Post < ActiveRecord::Base
  def self.default_scope
    where published: true
  end
end
Post.all                                  # Fires "SELECT * FROM posts WHERE published = true"
Post.unscoped.all                         # Fires "SELECT * FROM posts"
Post.where(published: false).unscoped.all # Fires "SELECT * FROM posts"

Answer 3

在 Player 类中，我们可以定义一个新的作用域 ：with_errors，它将取消默认的作用域：

class Player < ActiveRecord::Base
    default_scope { where(imported_with_errors: false) }
    scope :with_errors, -> { unscope(where: :imported_with_errors) }
end

因此，您可以使用它根据需要查找播放器：

Player.with_errors.find(params[:id])