两个域对象之间的多个关系

Question

我有两个域类：Contract和Orgainisation。合同有一个contractor（Orgaisation的实例）和多个/一个/无beneficiaries（也是Orgaisation的实例）。我如何建模这些关系？我希望Contract拥有这两种关系，以便我可以执行以下操作：

contractInstance = new Contract()
contractInstance.addToBeneficiaries(name: 'A Company')
contractInstance.addToBeneficiaries(name: 'Other Company')
contractInstance.contractor = new Orgaisation('Antoher Company')
contractInstance.save()

我尝试了一些事情，但不断收到错误消息（瞬态值，没有多对多关系的拥有类等等）

合同

static belongsTo = [contractor:Organisation]
static hasMany = [beneficiaries:Organisation]

orgainisation

static hasMany = [contractorContracts:Contract, beneficiariesContracts:Contract]

我如何表示这些关系？

编辑：我忘了提及合同受益人应该是一个多对多的协会（我希望在合同中重复使用受益人）。

Answer 1

我的解决方案是使用描述性名称明确M：M加入类。在你的情况下，似乎我们可以创建一个类ProvidedService或类似的东西，并具有：

Contract {
  static belongsTo = [contractor: Organization]
  static hasMany = [benefits: ProvidedService]
}
Organization {
  static hasMany = [contractorContracts: Contract, receivedServices: ProvidedService]
}
ProvidedService {
  //Feasibly there could be differences in the service provided to each beneficiary of a contract which could go in here.
  static belongsTo = [contract: Contract, serviceRecipient: Organization]
}