MongoDb 文档与内部对象连接

Question

我有 2 个名为 call 和 customers 的文档 我想加入对customers.location._id的呼叫的locationId

通话

      "_id": "5d456560221b9147e4af4b97",
      "customerId": "5d0a3bbfac9470aea56ad619",
      "locationId": "5d11d2c4cba8151f67f735b1",
      "startDateTime": "2019-06-21T05:30:00.000Z",
      "endDateTime": "2019-06-21T06:00:00.000Z"
    }

客户

      "_id": "5d0a3bbfac9470aea56ad619",
      "locations": [
        {
          "_id": "5d11d2c4cba8151f67f735b1",
          "phone": "9889599999",
          "ext": "91",
          "address": "sad",
          "neighborhood": "sda",
          "city": "punetest",
          "state": "MH",
          "zip": "589365",
          "country": "india",
          "isBillingAddress": false,
          "taxPercentage": 0,
          "type": "Residential",
          "status": "Active",
          "firstName": "A",
          "lastName": "B"
        },
        {
          "_id": "5d11e457cba8151f67f735b3",
          "phone": "969696999",
          "ext": "91",
          "address": "",
          "neighborhood": "",
          "city": "udaipur",
          "state": "raj",
          "zip": "312563",
          "country": "india",
          "isBillingAddress": false,
          "taxPercentage": 0,
          "type": "Residential",
          "status": "Deleted",
          "firstName": "AB",
          "lastName": "CD"
        }
      ],
      "createdAt": "2019-06-19T13:42:23.479Z",
      "updatedAt": "2019-06-25T13:39:07.597Z"
    }

    [
     {
        $lookup: {
          from: 'customers.locations',
          localField: 'locationId',
          foreignField: '_id',
          as: 'customers.locations',
        },
      }
     ]);

它不工作 我有 2 个名为 call 和客户的文档，我想将 locationId 加入到customers.location._id 的呼叫中

我要输出``` { "_id": "5d456560221b9147e4af4b97", "customerId": "5d0a3bbfac9470aea56ad619", "locationId": "5d11d2c4cba8151f67f735b1", “位置”：{“_id”：“5d11d2c4cba8151f67f735b1”， “电话”：“9889599999”， “分机”：“91”， “地址”：“悲伤”， “邻居”：“sda”， "城市": "punetest", “状态”：“MH”， “邮编”：“589365”， “国家”：“印度”， “isBillingAddress”：假， “税收百分比”：0， “类型”：“住宅”， “状态”：“活动”， “名字”：“A”， “姓氏”：“B”} }

Answer 1

好的，这就是您正在查看的内容：

如果您在calls中的locationId在customer中只有一个匹配的customer.locations._id：

 db.getCollection('calls').aggregate([
  {
    $lookup: {
      from: 'customers',
      localField: 'locationId',
      foreignField: 'locations._id',
      as: 'customersCalls',
    }
  }, { $unwind: '$customersCalls' },
  {
    $project: {
      customerId: 1, locationId: 1, locations: {
        $filter: {
          input: "$customersCalls.locations",
          as: "item",
          cond: { $eq: ["$$item._id", '$locationId'] }
        }
      }
    }
  },
  { $group: { _id: '$_id', result: { $first: '$$ROOT' } } },
  { $replaceRoot: { newRoot: "$result" } }
])

如果您在calls中的locationId在customer中有多个匹配的customer.locations._id：

db.getCollection('calls').aggregate([
  {
    $lookup: {
      from: 'customers',
      localField: 'locationId',
      foreignField: 'locations._id',
      as: 'customersCalls',
    }
  }, { $unwind: '$customersCalls' },
  {
    $project: {
      customerId: 1, locationId: 1, locations: {
        $filter: {
          input: "$customersCalls.locations",
          as: "item",
          cond: { $eq: ["$$item._id", '$locationId'] }
        }
      }
    }
  },
  { $group: { _id: '$_id', locations: { $push: { $arrayElemAt: ["$locations", 0] } }, result: { $first: '$$ROOT' } } },
  { $addFields: { 'result.locations': '$locations' } },
  { $replaceRoot: { newRoot: "$result" } }
])