如何使用MongoDb聚合3个集合的计数/总和？

我正在尝试聚合多个集合，并根据

createdAt

字段获取每日总计：

db={
  "agents": [
    {
      "_id": ObjectId("5a934e000ac2030405000370"),
      "name": "Book Now"
    }
  ],
  "tolls": [
    {
      "_id": ObjectId("5a934e000102030405000000"),
      "amountCollected": 20,
      "plaza": "Shimabala",
      "directionLane": "South/3",
      "cashier": "Chishala",
      "agent": {
        "_id": ObjectId("5a934e000ac2030405000370"),
        "name": "Book Now"
      },
      "createdAt": ISODate("2021-06-02T13:23:06.232Z")
    },
    {
      "_id": ObjectId("a9934ec001a203040500dc00"),
      "amountCollected": 150,
      "plaza": "Shimabala",
      "directionLane": "South/3",
      "cashier": "Chishala",
      "agent": {
        "_id": ObjectId("5a934e000ac2030405000370"),
        "name": "Book Now"
      },
      "createdAt": ISODate("2021-06-04T13:23:06.232Z")
    }
  ],
  "fuel": [
    {
      "_id": ObjectId("60b79e4e4afd77a1c27c730c"),
      "litres": 5.2,
      "price": 90,
      "station": "Chilanga",
      "fuelAttendant": "Manda",
      "agent": {
        "_id": ObjectId("5a934e000ac2030405000370"),
        "name": "Book Now"
      },
      "createdAt": ISODate("2021-06-04T16:06:16.232Z")
    }
  ]
}

预期成果：

[
  {
    "_id": "2021-06-02",
    "fuel": 0,
    "tolls": 1
  },
  {
    "_id": "2021-06-04",
    "fuel": 1,
    "tolls": 1
  }
]

因为两个集合连接到代理的集合，所以我有这个查询，但不确定如何从那里开始：

db.agents.aggregate([
  {
    "$lookup": {
      "localField": "_id",
      "from": "tolls",
      "foreignField": "agent._id",
      "as": "tolls"
    }
  },
  {
    "$unwind": {
      "path": "$tolls",
      "preserveNullAndEmptyArrays": true
    }
  },
  {
    "$lookup": {
      "localField": "_id",
      "from": "fuel",
      "foreignField": "agent._id",
      "as": "fuel"
    }
  },
  {
    "$unwind": {
      "path": "$fuel",
      "preserveNullAndEmptyArrays": true
    }
  } 
])

• 从

  收费查询
  收费

• $project

  显示必填字段并为“通行费”添加新字段

• $unionWith

  with

  fuel

  采集和

  $project

  显示必填字段为“fuel”添加新字段

  类型

• 现在，我们在根目录中合并了两个集合文档，并为每个文档添加了

  type

• $group

  按

  日期

  和

  类型

  计算元素总数

• $group

  仅按

  日期

  进行分组，并使用其

  计数

  键值格式构造这两种

  类型

  的数组

• $addFields

  使用

  $arrayToObject

结果是：

[
  {
    "_id": "2021-06-04",
    "analytic": {
      "fuel": 1,
      "tolls": 1
    }
  },
  {
    "_id": "2021-06-02",
    "analytic": {
      "tolls": 1
    }
  }
]

这不会添加0计数字段，您必须在前端/客户端对其进行管理

[
  {
    "_id": "2021-06-04",
    "analytic": {
      "fuel": 1,
      "tolls": 1
    }
  },
  {
    "_id": "2021-06-02",
    "analytic": {
      "tolls": 1
    }
  }
]