如何从三个 mongodb 集合中按条件分组和求和

Question

我有三个 mongodb 集合。我想按日期、月份和年份对集合进行分组，然后按条件求和，以便在一个表中显示三个集合的总计。但是，我在生成 mongodb 聚合代码时遇到了问题。

收藏A

{
  _id: "1",
  "Name": "John",
  "Booked": "Executive"
  "date": 2023 - 03 - 02 T18: 15: 26.723 + 00: 00
}, {
  _id: "2",
  "Name": "Peter",
  "Booked": "Economy",
  "date": 2023 - 03 - 19 T19: 15: 26.723 + 00: 00
}, {
  _id: "3",
  "Name": "Wade",
  "Booked": "Economy",
  "date": 2023 - 03 - 19 T19: 15: 26.723 + 00: 00
},

收藏B

{
  _id: "1",
  "Name": "John",
  "Amount": 200,
  "date": 2023 - 03 - 19 T19: 15: 26.723 + 00: 00
}, {
  _id: "2",
  "Name": "Peter",
  "Amount": 300,
  "date": 2023 - 03 - 19 T19: 15: 26.723 + 00: 00
}, {
  _id: "3",
  "Name": "Wade",
  "Amount": 100,
  "date": 2023 - 03 - 19 T19: 15: 26.723 + 00: 00
},

收藏C

{
  _id: "3",
  "Name": "Wade",
  "Country": "USA",
  "date": 2023 - 03 - 19 T19: 15: 26.723 + 00: 00
},

我希望能够按日期、月份和年份汇总经济舱预订总数，也能够按日期、月份和年份汇总客户的原籍国。

我怎样才能改进这段代码

collectionA.aggregate([
              {$lookup:
                {
                  from: "collectionB",
                  localField: "_id",
                  foreignField: "_id",
                  as: "collectionB"
                }
              },
              {$unwind: "$collectionB"},
              {$lookup:
                {
                   from: "collectionC",
                   localField: "_id",
                   foreignField: "_id",
                   as: "collectionC"
                }
              },
              {$unwind: "$collectionC"},
              {
                "$group": {
                  _id: {
                    year: {$year: "$date"},
                    month: {$month: "$date"},
                    dayOfMonth: {$dayOfMonth: "$date"},
                  },
                  "Economy": {
                    $sum: {
                      "$cond": [
                        {"$eq": ["$Booked", "Economy"]},
                        1,
                        0
                      ]
                    }
                  },
                  "USA": {
                    $sum: {
                      "$cond": [
                        {"$eq": ["$Country", "USA"]},
                        1,
                        0
                      ]
                    }
      
                  }
                }
              }
         ])

提前致谢