ruby-on-rails-3 - 在具有两个外键的一个模型与另一个模型之间创建关联

Question

与这种关联作斗争，我有两个模型：人偶和市场，市场是您可以与其他人交易您的玩具人偶的地方。

Figure class
  figure_id:integer
  name     :string
  image_url:string

Market class
  market_id:integer
  figure_you_want_to_trade_id         :integer #this should be associated with the figure_id
  figure_you_want_from_someone_else_id:integer #this should be associated with the figure_id

我该如何建立这个协会？

我在想：

market.rb
  has_many :figure_to_trade, :class_name => Figure, :foreign_key => figure_id
  has_many :figure_you_want, :class_name => Figure, :foreign_key => figure_id

figure.rb
  belongs_to :figure_you_want_to_trade, :class_name => Market
  belongs_to :figure_you_want_from_someone_else, :class_name => Market

这是我在尝试输出时收到的错误：<%= market.figure_to_trade %>

SQLite3::SQLException：没有这样的列：figures.figure_id: SELECT "figures".* FROM "figures" WHERE "figures"."figure_id" = 1

Answer 1

弄清楚了

market.rb
    belongs_to :figure_you_want_to_trade, :class_name => Figure
    belongs_to :figure_you_want_from_someone_else, :class_name => Figure

figure.rb
    has_many :figure_to_trade, :class_name => Market, :foreign_key => :figure_you_want_to_trade_id
    has_many :figure_you_want, :class_name => Market, :foreign_key => :figure_you_want_from_someone_else_id

然后我可以通过（假设 Figure 类具有名称：字符串）来调用它

<% @markets.each do |market| %>
  <%= market.figure_you_want_to_trade.name %>
  <%= market.figure_you_want_from_someone_else.name %>
<% end %>