Ruby on Rails的 - 无法协会工作

Question

另一个nooby的问题 - 我有这两款车型在我的项目：

class Invoice < ActiveRecord::Base 
    has_many :items 
end 

和

class Item < ActiveRecord::Base 
    belongs_to :invoice ,:foreign_key=>'invoice_number',:primary_key=>'invoice_number' 
end 

在我的控制器

所以，我想增加新通过按下绑定到某个动作的按钮将该项目添加到发票中。该行动将生成一个表格，让客户填写有关该项目的信息。我想这样的事情在控制器：

@invoice.items << Item.new 

此操作可能是错的，但问题是，Rails的告诉我，有取消定义方法“项目”。有人可以给我一个关于如何解决这个问题的提示吗？

以下是错误跟踪：

activemodel (3.2.8) lib/active_model/attribute_methods.rb:407:in `method_missing' 
activerecord (3.2.8) lib/active_record/attribute_methods.rb:149:in `method_missing' 
app/controllers/return_controller.rb:4:in `index' 
actionpack (3.2.8) lib/action_controller/metal/implicit_render.rb:4:in `send_action' 
actionpack (3.2.8) lib/abstract_controller/base.rb:167:in `process_action' 
actionpack (3.2.8) lib/action_controller/metal/rendering.rb:10:in `process_action' 
actionpack (3.2.8) lib/abstract_controller/callbacks.rb:18:in `block in process_action' 
activesupport (3.2.8) lib/active_support/callbacks.rb:414:in `_run__3004877794972512718__process_action__435319474484567757__callbacks' 
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.8) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks' 
activesupport (3.2.8) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.8) lib/abstract_controller/callbacks.rb:17:in `process_action' 
actionpack (3.2.8) lib/action_controller/metal/rescue.rb:29:in `process_action' 
actionpack (3.2.8) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' 
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `block in instrument' 
activesupport (3.2.8) lib/active_support/notifications/instrumenter.rb:20:in `instrument' 
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `instrument' 
actionpack (3.2.8) lib/action_controller/metal/instrumentation.rb:29:in `process_action' 
actionpack (3.2.8) lib/action_controller/metal/params_wrapper.rb:207:in `process_action' 
activerecord (3.2.8) lib/active_record/railties/controller_runtime.rb:18:in `process_action' 
actionpack (3.2.8) lib/abstract_controller/base.rb:121:in `process' 
actionpack (3.2.8) lib/abstract_controller/rendering.rb:45:in `process' 
actionpack (3.2.8) lib/action_controller/metal.rb:203:in `dispatch' 
actionpack (3.2.8) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' 
actionpack (3.2.8) lib/action_controller/metal.rb:246:in `block in action' 
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:73:in `call' 
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:73:in `dispatch' 
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:36:in `call' 
journey (1.0.4) lib/journey/router.rb:68:in `block in call' 
journey (1.0.4) lib/journey/router.rb:56:in `each' 
journey (1.0.4) lib/journey/router.rb:56:in `call' 
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:600:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' 
rack (1.4.1) lib/rack/etag.rb:23:in `call' 
rack (1.4.1) lib/rack/conditionalget.rb:25:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/head.rb:14:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/params_parser.rb:21:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/flash.rb:242:in `call' 
rack (1.4.1) lib/rack/session/abstract/id.rb:205:in `context' 
rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/cookies.rb:339:in `call' 
activerecord (3.2.8) lib/active_record/query_cache.rb:64:in `call' 
activerecord (3.2.8) lib/active_record/connection_adapters/abstract/connection_pool.rb:473:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call' 
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `_run__2876506060705866238__call__963306619056181882__callbacks' 
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.8) lib/active_support/callbacks.rb:385:in `_run_call_callbacks' 
activesupport (3.2.8) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.8) lib/action_dispatch/middleware/callbacks.rb:27:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/reloader.rb:65:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/remote_ip.rb:31:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call' 
railties (3.2.8) lib/rails/rack/logger.rb:26:in `call_app' 
railties (3.2.8) lib/rails/rack/logger.rb:16:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/request_id.rb:22:in `call' 
rack (1.4.1) lib/rack/methodoverride.rb:21:in `call' 
rack (1.4.1) lib/rack/runtime.rb:17:in `call' 
activesupport (3.2.8) lib/active_support/cache/strategy/local_cache.rb:72:in `call' 
rack (1.4.1) lib/rack/lock.rb:15:in `call' 
actionpack (3.2.8) lib/action_dispatch/middleware/static.rb:62:in `call' 
railties (3.2.8) lib/rails/engine.rb:479:in `call' 
railties (3.2.8) lib/rails/application.rb:223:in `call' 
rack (1.4.1) lib/rack/content_length.rb:14:in `call' 
railties (3.2.8) lib/rails/rack/log_tailer.rb:17:in `call' 
rack (1.4.1) lib/rack/handler/webrick.rb:59:in `service' 
/usr/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service' 
/usr/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run' 
/usr/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread' 

，并在控制台它说：

NoMethodError (undefined method `items' for #<Invoice:0x00000002b822c8>): 
app/controllers/invoice_controller.rb:4:in `index' 

反馈的问题： 感谢您你们帮我在这mass.I已经解决了这个问题 - 我发现了一个拼写错误（缺少''），我很抱歉花时间。 再次感谢

Answer 1

您是否在数据库中创建这些模型并给出商品invoice_number？

rails g migration AddInvoiceNumberToItems invoice_number:integer 
rake db:migrate