Javascript 如何使用node.js在mongodb中获得按组名分组的聚合值？_Javascript_Node.js_Mongodb_Mongoose

Javascript 如何使用node.js在mongodb中获得按组名分组的聚合值？

javascript node.js mongodb mongoose

Javascript 如何使用node.js在mongodb中获得按组名分组的聚合值？,javascript,node.js,mongodb,mongoose,Javascript,Node.js,Mongodb,Mongoose,我有一个用例，其中我有3个集合。i、 e、模板、组和每个模板的1-动态集合，将在创建模板后立即创建每个模板由设备组成，每个设备由组集合的组ID组成。动态收集存储模板设备推送的数据现在，我需要找出Groups集合中按groupName分组的设备的聚合（总和）值以下是我收集的样本数据模板数据 { "_id": "5e0ae38729218b0a3861118b", "templateId": "27127206822", "devices": [ { "dev

我有一个用例，其中我有3个集合。i、 e、模板、组和每个模板的1-动态集合，将在创建模板后立即创建

每个

模板

由

设备

组成，每个

设备

由组集合的

组ID

组成。动态收集存储模板设备推送的数据

现在，我需要找出Groups集合中按groupName分组的设备的聚合（总和）值

以下是我收集的样本数据

模板数据

{
  "_id": "5e0ae38729218b0a3861118b",
  "templateId": "27127206822",
  "devices": [
    {
      "deviceId": "waterTest",
      "_id": "5e0ae49629218b0a3861118f",
      "group": "5e0ae41d29218b0a3861118d",
    },{
       "deviceId": "Test",
       "_id": "5e0af166981f39410cd89b72",
       "group": "5e0af11d981f39410cd89b70"
    }]
}

[
  {
    "_id": "5e0ae793b1384737a4f855cf",
    "template": "27127206822",
    "deviceId": "waterTest",
    "heat" : 20,
    "humidity" : 10
   },{
      "_id": "5e0ae7a2b1384737a4f855d0",
      "template": "27127206822",
      "deviceId": "waterTest",
      "heat" : 40,
      "humidity" : 20
   },{
      "_id": "5e0ae890b1384737a4f855d3",
      "template": "27127206822",
      "deviceId": "waterTest",
      "heat" : 60,
      "humidity" : 50
    },{
       "_id": "5e0af188981f39410cd89b73",
       "template": "27127206822",
       "deviceId": "Test",
       "heat": 60,
       "humidity": 50
   },{
      "_id": "5e0af196981f39410cd89b74",
      "template": "27127206822",
      "deviceId": "Test",
      "heat": 10,
      "humidity": 20
   }]

[{
   "_id": "5e0af11d981f39410cd89b70",
   "template": "5e0ae38729218b0a3861118b",
   "groupName": "Flats"
 },{
    "_id": "5e0ae41d29218b0a3861118d",
    "template": "5e0ae38729218b0a3861118b",
    "groupName": "SPool"
 }]

动态采集数据

{
  "_id": "5e0ae38729218b0a3861118b",
  "templateId": "27127206822",
  "devices": [
    {
      "deviceId": "waterTest",
      "_id": "5e0ae49629218b0a3861118f",
      "group": "5e0ae41d29218b0a3861118d",
    },{
       "deviceId": "Test",
       "_id": "5e0af166981f39410cd89b72",
       "group": "5e0af11d981f39410cd89b70"
    }]
}

[
  {
    "_id": "5e0ae793b1384737a4f855cf",
    "template": "27127206822",
    "deviceId": "waterTest",
    "heat" : 20,
    "humidity" : 10
   },{
      "_id": "5e0ae7a2b1384737a4f855d0",
      "template": "27127206822",
      "deviceId": "waterTest",
      "heat" : 40,
      "humidity" : 20
   },{
      "_id": "5e0ae890b1384737a4f855d3",
      "template": "27127206822",
      "deviceId": "waterTest",
      "heat" : 60,
      "humidity" : 50
    },{
       "_id": "5e0af188981f39410cd89b73",
       "template": "27127206822",
       "deviceId": "Test",
       "heat": 60,
       "humidity": 50
   },{
      "_id": "5e0af196981f39410cd89b74",
      "template": "27127206822",
      "deviceId": "Test",
      "heat": 10,
      "humidity": 20
   }]

[{
   "_id": "5e0af11d981f39410cd89b70",
   "template": "5e0ae38729218b0a3861118b",
   "groupName": "Flats"
 },{
    "_id": "5e0ae41d29218b0a3861118d",
    "template": "5e0ae38729218b0a3861118b",
    "groupName": "SPool"
 }]

集团数据

{
  "_id": "5e0ae38729218b0a3861118b",
  "templateId": "27127206822",
  "devices": [
    {
      "deviceId": "waterTest",
      "_id": "5e0ae49629218b0a3861118f",
      "group": "5e0ae41d29218b0a3861118d",
    },{
       "deviceId": "Test",
       "_id": "5e0af166981f39410cd89b72",
       "group": "5e0af11d981f39410cd89b70"
    }]
}

[
  {
    "_id": "5e0ae793b1384737a4f855cf",
    "template": "27127206822",
    "deviceId": "waterTest",
    "heat" : 20,
    "humidity" : 10
   },{
      "_id": "5e0ae7a2b1384737a4f855d0",
      "template": "27127206822",
      "deviceId": "waterTest",
      "heat" : 40,
      "humidity" : 20
   },{
      "_id": "5e0ae890b1384737a4f855d3",
      "template": "27127206822",
      "deviceId": "waterTest",
      "heat" : 60,
      "humidity" : 50
    },{
       "_id": "5e0af188981f39410cd89b73",
       "template": "27127206822",
       "deviceId": "Test",
       "heat": 60,
       "humidity": 50
   },{
      "_id": "5e0af196981f39410cd89b74",
      "template": "27127206822",
      "deviceId": "Test",
      "heat": 10,
      "humidity": 20
   }]

[{
   "_id": "5e0af11d981f39410cd89b70",
   "template": "5e0ae38729218b0a3861118b",
   "groupName": "Flats"
 },{
    "_id": "5e0ae41d29218b0a3861118d",
    "template": "5e0ae38729218b0a3861118b",
    "groupName": "SPool"
 }]

现在看看我到目前为止编写的聚合查询

let templateId = "27127206822"; // Dynamic Collection

[err, templateData] = await to(mongoose.connection.db.collection(templateId)
  .aggregate([
     {
          $lookup:{
             from:"templates",
             localField:"template",
             foreignField:"templateId",
             as:"template"
          }
      },{ 
          $unwind:"$template"
      },{ 
          $unwind:"$template.devices"
      },{
          $lookup:{
             from:"groups",
             localField:"template.devices.group",
             foreignField:"_id",
             as:"group"
          }
      },{
          $unwind:"$group"
      },{
          $group:{
             _id: "$groupData.groupName",
             heat:{$sum:"$heat"},
             humidity:{$sum:"$humidity"},
             count:{$sum:1}
          }
      }]));

现在，我需要得到组集合的

groupName

分组的每个

设备的热和湿度的总和。但是我得到了错误的数据。i、 e，一组的总和也被加到所有其他组中
**返回输出**
//Am getting this Data
[
  {
    "_id": "Flats",
    "heat": 190,  // 2 group's data getting added in both the groups
    "humidity": 150,
    "count":5
  },{
    "_id": "SPool",
    "heat": 190,
    "humidity": 150,
    "count":5
  }]

预期产出
[
  {
    "_id": "Flats",
    "heat": 70,
    "humidity": 70,
    "count":2
  },{
    "_id": "SPool",
    "heat": 120,
    "humidity": 80,
    "count":3
  }]

要得到所需的结果，我是否遗漏了什么？
您可以将其添加为下一个聚合阶段，并将其用于计数和相加：
{
    $group: {
        _id: "$group.groupName",
        "count": { $sum: 1 },
        "heat": { $sum: "$heat" },
        "humidity": { $sum: "$humidity" }
    }
}

更新：
我解决了这个问题。一旦$unwind:“$template.devices”
完成，每个文档都会获得$template.devices
数组中的每个设备，并使用该数组复制文档
因此，为了得到正确的答案，我们需要将deviceId
与每个文档的template.devices
对象的deviceId进行匹配
问题是
[err, templateData] = await to(mongoose.connection.db.collection(templateId)
  .aggregate([
     {
          $lookup:{
             from:"templates",
             localField:"template",
             foreignField:"templateId",
             as:"template"
          }
      },{ 
          $unwind:"$template"
      },{ 
          $unwind:"$template.devices"
      },{
          $match:{
            $expr:{
              $eq: [ "$deviceId","$template.devices.deviceId" ]
            }
          }
      },{
          $lookup:{
             from:"groups",
             localField:"template.devices.group",
             foreignField:"_id",
             as:"group"
          }
      },{
          $unwind:"$group"
      },{
          $group:{
             _id: "$groupData.groupName",
             heat:{$sum:"$heat"},
             humidity:{$sum:"$humidity"},
             count:{$sum:1}
          }
      }]));

通过使用它，我们将获得预期的输出。就是
[
  {
    "_id": "Flats",
    "heat": 70,
    "humidity": 70,
    "count":2
  },{
    "_id": "SPool",
    "heat": 120,
    "humidity": 80,
    "count":3
  }]

为什么您要尝试使用外部模板ID
查找$lookup
本地模板
？我看不到任何方法可以在“13435158964”
和动态集合中的任何值之间进行匹配。我已经使用了它，并且工作正常。但每组都得到了相同的结果。像这样，[{u id:“游泳池”，“热量”：1498，“湿度”：3924}，{{u id:“平坦”，“热量”：1498，“湿度”：3924}，{{u id:“游泳池”，“热量”：1498，“湿度”：3924}，{“_id”：“公共区域”，“热量”：1498，“湿度”：3924}]
@Aravind他们都引用同一个模板吗？你需要调试你的管道-我首先从$lookup
开始，看看你是否得到了预期的结果，添加下一个阶段etcYeah，@mickl。他们都引用同一个模板。我想，我发现了问题。实际上，每个组的数据都被添加到了所有组中。但是如何在获取总数时区分组名？@Aravind你能编辑你的问题并展示一个这样的例子吗？@Aravind我猜你是从多个组获取数据，因为你是按groupName
分组的，更好的方法是用\u id
替换groupName
，然后添加>groupName:{$first:$groupName}
到$group
阶段