使用 Waterline ORM / SailsJS 查询连接结果

Question

我有 2 个模型：

• 手术
• 米（不应该是复数，但现在省略它;）

一个仪表有许多操作。

我应该如何获得 operation.Name 知道 Meter.ID ？

这是我的 2 个模型：

手术：

module.exports = {

  attributes: {

    Id: {type: 'string'}, // operation_id
    name: {type: 'string', required: true},
    meters: {
      collection: 'meters',
      via: 'operation'
    }
  },
};

米：

module.exports = {

  attributes: {
    Id: {type: 'string', required: true, unique: true}, // meter_id
    name: {type: 'string', required: true},
    state: {type: 'number', required: true},
    operation: {
      model: 'operation',
    }
  },
};

Answer 1

// myApp/api/models/meter.js
// A meter may have many operations
module.exports = {
  attributes: {
    Id: {type: 'string', required: true, unique: true}, // meter_id
    name: {type: 'string', required: true},
    state: {type: 'number', required: true},

    // Add a reference to operations
    operations: {
      collection: 'operations',
      via: 'meter'
    }
  }
};


// myApp/api/models/operation.js
// A operation may only belong to a single meter
module.exports = {
  attributes: {
    Id: {type: 'string'}, // operation_id
    name: {type: 'string', required: true},

    // Add a reference to User
    meter: {
      model: 'meter'
    }
  }
};


var meters = await Meters.find(id: 123).populate('operations');
// The meters object would look something like the following
// [{
//   id: 123,
//   name: 'Foo',
//   state: '1',
//   meters: [{
//     id: 1,
//     name: 'mymeter',
//     user: 123
//   }]
// }]

希望这对你有帮助:)