Ruby/Sinatra/DataMapper多对多如何创建对象

Question

我有两个类叫做User和Gig，还有一个连接表Usergig。

  class Usergig
    include DataMapper::Resource
    property :id, Serial
    belongs_to :user
    belongs_to :gig
  end
  class Gig
    include DataMapper::Resource
    property :id, Serial
    property :gigname, String
    property :gigtext, Text
    has n, :usergigs
    has n, :users, :through => :usergigs
  end
  class User
    include DataMapper::Resource
    property :id, Serial
    property :username, String
    property :realname, String
    has n, :usergigs
    has n, :gigs, :through => :usergigs
  end

当我试图运行:

  post '/gig/add' do
    user = User.get(1)
    gig = user.gigs.create(:gigname => params[:gig_gigname], :gigtext => params[:gig_gigtext])
  end

我得到错误:在/gig/add处出现错误未定义的方法' include?' for nil:NilClass

我已经在谷歌上搜索了大约两个小时，并阅读了DataMapper文档。有人知道我哪里做错了吗?

Answer 1

在Usergig中尝试以下操作:

belongs_to :user, :key => true
belongs_to :gig, :key => true

Answer 2

您忘记调用DataMapper.finalize…这是加载所有模型后需要调用的函数。在Sinatra中，你必须手动调用它