Question

在这个协会中苦苦挣扎，我有两种模式：图和市场，你可以在市场上与其他人交换你的玩具形象。

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

如何进行此关联？

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：＆lt;％= market.figure_to_trade％＆gt;

SQLite3 :: SQLException：没有这样的列：figures.figure_id：SELECT“数字”。* FROM“数字”WHERE“数字”。“figure_id”= 1

Answer 1

想出来

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

然后我可以调用它（假设Figure类有名字：string）

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

在具有两个foreign_keys的模型与另一个模型之间创建关联

1 个答案: