Question

我将关于我的数据库中议会事务的数据保存为Affair，该数据可以属于Councillor或Group。我是Ruby和ActiveRecord的新手。在以前的RoR版本中，我会使用has_and_belongs_to_many，它也可以使用。

class Councillor < ActiveRecord::Base
  has_many :affair_holdings, :foreign_key => :councillor_id
  has_many :affairs, through: :affair_holdings
end

class Affair < ActiveRecord::Base
  has_many :affair_holdings, :foreign_key => :affair_id
  has_many :councillors, through: :affair_holdings
end

class Affair_Holdings < ActiveRecord::Base
  belongs_to :affair
  belongs_to :councillor
end

稍后在代码中，我想建立一个新的关联：

affair.councillors << Councillor.find_by(:id => 3)

但无论如何它都不起作用。它给我一个错误信息：

/Users/me/.rvm/gems/ruby-2.0.0-p353/gems/activerecord-4.0.2/lib/active_record/inheritance.rb:125:in `compute_type': uninitialized constant Affair::AffairHolding (NameError)
from /Users/me/.rvm/gems/ruby-2.0.0-p353/gems/activerecord-4.0.2/lib/active_record/reflection.rb:178:in `klass'
from /Users/me/.rvm/gems/ruby-2.0.0-p353/gems/activerecord-4.0.2/lib/active_record/associations/association.rb:123:in `klass'
from /Users/me/.rvm/gems/ruby-2.0.0-p353/gems/activerecord-4.0.2/lib/active_record/associations/collection_association.rb:37:in `reader'
from /Users/me/.rvm/gems/ruby-2.0.0-p353/gems/activerecord-4.0.2/lib/active_record/associations/builder/association.rb:70:in `affair_holdings'
from crawl.rb:196:in `affair'
from crawl.rb:233:in `<main>'

我的错是什么？我怎么解决这个问题？谢谢你的帮助。

Answer 1

班级名称应为AffairHolding而不是Affair_Holdings。

Answer 2

是类名应该是AffairHolding，并且总是使用单数和首字母大写字母作为类名

has_many / belongs_to RoR中的唯一关联

2 个答案: