0

我有一堂课，Page. 我想打电话page.next_page，甚至page.page想得到下一页。当我创建一个新Page页面时，我想将我的最后一页关联到Book我创建next_page的新页面中Page。

class AddNextPageToPages < ActiveRecord::Migration
  def change
   add_column :pages, :page, :references
 end
end

此迁移失败。

```

-- add_column(:pages, :next_page, {:class_name=>"Page"})
rake aborted!
An error has occurred, this and all later migrations canceled:

undefined method `to_sym' for {:class_name=>"Page"}:Hash/Users/username/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.12/lib/active_record/connection_adapters/sqlite_adapter.rb:395:in     `valid_alter_table_options'

```

4

1 回答 1

-1

您可以阅读 rails http://guides.rubyonrails.org/v3.2.13/migrations.html中的迁移来处理。

于 2013-06-29T03:38:31.447 回答