从 rails 2.3 迁移到 rails 3.1 时出现活动记录错误

Question

我正在从 Rails 2.3 应用程序迁移到 Rails 3.1，尝试保存记录时出现此错误。这不是早些时候发生的，我不确定可能是什么原因，任何帮助将不胜感激，谢谢。

这是我的模型的预览

**

class Store < ActiveRecord::Base 
has_many :orders
end

**

**

class Order < ActiveRecord::Base 
has_many :items, :dependent => :delete_all
end

**

**

class Item < ActiveRecord::Base 
belongs_to :order
validates_presence_of :order_id
end

**

以下是我尝试保存时的错误消息日志

**

ActiveRecord::RecordInvalid: Validation failed: Items order can't be blank
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/validations.rb:56:in `save!'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/attribute_methods/dirty.rb:33:in `save!'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/transactions.rb:246:in `block in save!'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/transactions.rb:295:in `block in with_transaction_returning_status'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/connection_adapters/abstract/database_statements.rb:194:in `transaction'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/transactions.rb:208:in `transaction'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/transactions.rb:293:in `with_transaction_returning_status'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/activerecord-3.1.12/lib/active_record/transactions.rb:246:in `save!'
    from (irb):16
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/railties-3.1.12/lib/rails/commands/console.rb:45:in `start'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/railties-3.1.12/lib/rails/commands/console.rb:8:in `start'
    from /Users/branch/.rvm/gems/ruby-1.9.3-p484/gems/railties-3.1.12/lib/rails/commands.rb:40:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'
1

**

当我尝试通过控制台保存订单时。主键被保存为 nil。

o = st.orders.new(:store_order_id => "1M",:date_time => Time.now)

这是我看到的时候

o.save

#<Order id: nil, store_order_id: "12121M", date_time: nil>

下面是我的订单控制器创建代码的预览

def create
@order = @store.orders.new(params[:order])
@order.save

end

Answer 1

你的问题是你不能这样做：

validates_presence_of :order_id

在项目模型中。原因很简单：Order id 是在验证后创建的，因此不存在。

有几件事要做：

1. 添加反向关系
2. 将您的验证更改为仅检查是否存在“order”，而不是“order_id”

代码如下：

class Order < ActiveRecord::Base 
  has_many :items, :inverse_of => :order, :dependent => :delete_all
end

class Item < ActiveRecord::Base 
  belongs_to :order, :inverse_of => :items
  validates_presence_of :order
end