ruby-on-rails - rails : NameError: uninitialized constant OrderItem

Question

models/order_item.rb

class OrderItem < ActiveRecord::Base    
  belongs_to :item
  belongs_to :order 
  belongs_to :user
end

models/order.rb

 class Order < ActiveRecord::Base   
     has_many :order_item
 end

现在，我使用 rails console 测试它们。当我输入 OrderItem 时，它抛出了

NameError: uninitialized constant OrderItem

更新

我是在 rails console 中完成的

2.1.3 :021 >   reload!
Reloading...
 => true 
2.1.3 :022 > Order
 => Order(id: integer, user_id: integer, created_at: datetime, updated_at: datetime, status: integer) 
2.1.3 :023 > Item
 => Item(id: integer, status: integer, name: string, price: integer, descript: text, created_at: datetime, updated_at: datetime, cover_file_name: string, cover_content_type: string, cover_file_size: integer, cover_updated_at: datetime, cate_id: integer) 
2.1.3 :024 > User
 => User(id: integer, email: string, encrypted_password: string, created_at: datetime, updated_at: datetime) 
2.1.3 :025 > OrderItem
NameError: uninitialized constant OrderItem
    from (irb):25
    from /Users/Coda/.rvm/gems/ruby-2.1.3@rails416/gems/railties-4.2.3/lib/rails/commands/console.rb:110:in `start'
    from /Users/Coda/.rvm/gems/ruby-2.1.3@rails416/gems/railties-4.2.3/lib/rails/commands/console.rb:9:in `start'
    from /Users/Coda/.rvm/gems/ruby-2.1.3@rails416/gems/railties-4.2.3/lib/rails/commands/commands_tasks.rb:68:in `console'
    from /Users/Coda/.rvm/gems/ruby-2.1.3@rails416/gems/railties-4.2.3/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
    from /Users/Coda/.rvm/gems/ruby-2.1.3@rails416/gems/railties-4.2.3/lib/rails/commands.rb:17:in `<top (required)>'
    from /Users/Coda/Desktop/code/ruby_pra/shop/bin/rails:8:in `<top (required)>'
    from /Users/Coda/.rvm/rubies/ruby-2.1.3/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /Users/Coda/.rvm/rubies/ruby-2.1.3/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from -e:1:in `<main>'

Answer 1

NameError: uninitialized constant OrderItem

has_many 的关联名称 应该是复数，所以更改 has_many :order_item 到 has_many :order_items in order.rb

#order.rb
class Order < ActiveRecord::Base   
  has_many :order_items #plural
end

更新:

查看您在 github 上的代码，order_item 和 .rb 之间有一个空格 即，(order_item .rb) 在文件名(app/models/order_item .rb ).将其更改为 order_item.rb