has_one:through不提供build_association

Question

TimeLog可以是开票还是不开票,而发票包含许多时间日志.我们的数据库不能有可空的外键,所以我们使用的是连接模型.代码:

class TimeLog < ActiveRecord::Base
  has_one :invoices_time_logs
  has_one :invoice, through: :invoices_time_logs
end

class Invoice < ActiveRecord::Base
  has_many :invoices_time_logss
  has_many :time_logs, through: :invoices_time_logss
end

class InvoicesTimeLogs
  belongs_to :invoice
  belongs_to :time_log
end

Invoice.first.time_logs.build工作正常,但TimeLog.first.build_invoice给出

NoMethodError:#TimeLog:0x4acd588>的未定义方法`build_invoice'

是不是has_one应该使build_association方法可用？

更新:

我为这个问题做了一个样本回购:build_assocation_test.要查看问题,请克隆存储库,安装捆绑包,运行迁移(或加载架构),然后在rails控制台中:

Invoice.create
Invoice.first.time_logs.build
TimeLog.create
TimeLog.first.build_invoice

Answer 1

我相信你有一个错字。

class Invoice < ActiveRecord::Base
  has_many :invoices_time_logss
  has_many :time_logs, through: :invoices_time_logss
end

应该...

class Invoice < ActiveRecord::Base
  has_many :invoices_time_logs
  has_many :time_logs, through: :invoices_time_logs
end

不？