Sequelize.js - 如何在没有原始 SQL 的情况下创建非平凡的关联?

Sequelize.js - How to create non-trivial associations without raw SQL?

这是我的情况:

我正在使用 postgres 9.4,Sequelize ORM 并具有以下模型:

我需要构建填充有 Service 和 ServiceGroup 对象的 Task 对象。 示例:

In database:
Service {
  serviceCode: '123232',
  serviceTitle: 'svc title #1',
}

ServiceGroup {
  serviceCodePrefix: ['12', '13', '92', ...],
  serviceGroupTitle: 'svc grp title #1',
}

Task {
  serviceCode: '123232',
}

Result:
Task {
  service: {
    serviceTitle: 'svc title #1',
  },
  serviceGroup: {
    serviceGroupTitle: 'svc grp title #1',
  },
}

问题在于 serviceCodePrefix 包含的不是简单的 ID,它可用于使用 hasOne/belongsTo/etc 创建关联,而是 ID 的前缀。

所以问题是:没有原始 sql 如何做到这一点?

事实证明,现在 Sequelize 具有实验性功能:'on' 'include' 选项。此选项允许用户自定义加入条件。所以我的问题可以这样解决:

const Service = sequelize.define('service', {
  serviceTitle: Sequelize.STRING,
  serviceCode: Sequelize.STRING,
});

const ServiceGroup = sequelize.define('service_group', {
  serviceGroupTitle: Sequelize.STRING,
  // Array of prefixes (e.g. ['01%', '023%'])
  serviceCodePrefix: Sequelize.ARRAY(Sequelize.STRING),
});

const Task = sequelize.define('task', {
  taskTitle: Sequelize.STRING,
  serviceCode: Sequelize.STRING,
});

Task.belongsTo(Service, { foreignKey: 'serviceCode' });

// Hack needed to allow 'include' option to work
Task.hasMany(ServiceGroup, { foreignKey: 'serviceCodePrefix', constraints: false });

// And finally
Task.findAll({
  include: [
    { model: Service },
    {
      model: ServiceGroup,
      on: [' "task"."serviceCode" LIKE ANY("serviceGroup"."serviceCodePrefix") '],
    },
  ],
});

虽然不确定性能。