按月对记录进行分组并对其进行计数 - Mongoose、nodeJs、mongoDb

fak*_*e97 1 mongoose mongodb node.js mongodb-query aggregation-framework

我需要在数据库(猫鼬)中查询并获取一种特定产品(一年内)一年中每个月的销售额。

我是节点和 mongoDb 的新手,我提供了一个“虚拟”解决方案,我在数据库中查询并获取一个产品的所有结果,然后我使用 3 个循环在几个月内分割结果,但我认为它使用了更多资源比应有的资源多,如果填充了更多数据,它将使用更多资源,因此我需要帮助进行数据库查询来解决该问题。

这是我的代码的一部分:

假设需要从17-02-202017-02-2019的结果,我知道如果是从1 月12 月,它将毫无意义地进入一个循环,但我还有另一部分代码控制它是否需要 1年份结果例如:01-01-202031-12-2020它不会执行下面的代码,我正在谈论的代码只有一个循环哈哈。

let startTime = performance.now();
Sales.find({productId:req.params.productId, "created_at": { "$gte": oneYearFromNow, "$lte": dateNow}}).then(result => {
        let newMonthsArray= new Array();
        let monthsArray = ['January','February','March','April','May','June','July','August','September','October', 'November','December'];
        let months = {};
        for(let i=parseInt(req.params.startDate.substring(5,7))-1; i<12; i++){
            let year = parseInt(req.params.startDate.substring(0,4))-1;
            let month = parseInt(req.params.startDate.substring(5,7));
            newMonth = monthsArray[i] + '-' + year;
            newMonthsArray.push(newMonth);
            months[newMonth] = 0; 
        }

        for(let i=0; i<parseInt(req.params.startDate.substring(5,7)); i++){
            let year = parseInt(req.params.startDate.substring(0,4));
            let month = parseInt(req.params.startDate.substring(5,7));
            newMonth = monthsArray[i] + '-' + year;
            newMonthsArray.push(newMonth);
            months[newMonth] = 0; 
          }

        for(i=0; i<result.length; i++){
            let getDate = result[i].created_at.toISOString();
            let year = getDate.substring(0,4);
            let month = parseInt(getDate.substring(5,7));
            let monthName = monthsArray[month-1];
            let date =  monthName + '-' + year;
            let count = Number(months[date]) + 1;
            months[date] = count;
        }

        let endTime = performance.now();
        res.status(200).send({Data: months, 'Execution time': endTime - startTime + ' mls'});
    });
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我希望一切都清楚,我想我需要使用聚合,但我不知道如何!

样本数据:

{
    {
        "created_at": "2020-04-04T17:02:07.832Z",
        "updated_at": "2020-04-04T17:02:07.832Z",
        "_id": "5e88bdcda3080736ac70f9c1",
        "price": 16800,
        "productId": "5e88bf90b9e5102ae46b154e",
        "__v": 0
    },
    {
        "created_at": "2020-04-04T17:02:07.832Z",
        "updated_at": "2020-04-04T17:02:07.832Z",
        "_id": "5e88bdf9a3080736ac70f9c2",
        "price": 12800,
        "productId": "5e88bf90b9e5102ae46b154e",
        "__v": 0
    }
}
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期望的结果:

在此输入图像描述

pra*_*ad_ 6

这是一个返回预期输出的聚合查询。一些示例文档:

[
  { created_at: "2020-04-04T17:02:07.832Z", productId: 1 },
  { created_at: "2020-02-01T17:02:07.832Z", productId: 1 },
  { created_at: "2020-02-19T17:02:07.832Z", productId: 1 },
  { created_at: "2019-05-22T17:02:07.832Z", productId: 1 },
  { created_at: "2020-01-15T17:02:07.832Z", productId: 1 },
  { created_at: "2020-01-30T17:02:07.832Z", productId: 2 },  // not selected
  { created_at: "2019-03-15T17:02:07.832Z", productId: 1 }   // not selected
]
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输入变量和聚合:

let TODAY = "2020-04-06T23:59:59"
let YEAR_BEFORE = "2019-04-07T00:00:00"
let req = { params: { productId: 1 } }
const monthsArray = [ 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December' ]

db.sales.aggregate( [
  { 
      $match: { 
          productId: req.params.productId, 
          created_at: { $gte: YEAR_BEFORE, $lte: TODAY }
      }
  },
  { 
      $group: {
          _id: { "year_month": { $substrCP: [ "$created_at", 0, 7 ] } }, 
          count: { $sum: 1 }
      } 
  },
  {
      $sort: { "_id.year_month": 1 }
  },
  { 
      $project: { 
          _id: 0, 
          count: 1, 
          month_year: { 
              $concat: [ 
                 { $arrayElemAt: [ monthsArray, { $subtract: [ { $toInt: { $substrCP: [ "$_id.year_month", 5, 2 ] } }, 1 ] } ] },
                 "-", 
                 { $substrCP: [ "$_id.year_month", 0, 4 ] }
              ] 
          }
      } 
  },
  { 
      $group: { 
          _id: null, 
          data: { $push: { k: "$month_year", v: "$count" } }
      } 
  },
  {
      $project: { 
          data: { $arrayToObject: "$data" }, 
          _id: 0 
      } 
  }
] )
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输出:

{
        "data" : {
                "May-2019" : 1,
                "January-2020" : 1,
                "February-2020" : 2,
                "April-2020" : 1
        }
}
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这是更新后的聚合

请注意以下更改:(1) 新常量 FIRST_MONTH 和 LAST_MONTH,(2) 将monthsArray变量名称更改为 MONTHS_ARRAY,(3) 添加 3 个新的管道阶段。

前两个管道阶段(新)构建包含所有月份的模板(涵盖起始和结束输入日期范围)。第三个新阶段将模板与从先前聚合导出的输出数据合并。

const FIRST_MONTH = 1
const LAST_MONTH = 12
const MONTHS_ARRAY = [ 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December' ]

let TODAY = "2020-04-06T23:59:59"
let YEAR_BEFORE = "2019-04-07T00:00:00"

db.sales.aggregate( [
  { 
      $match: { 
          productId: req.params.productId, 
          created_at: { $gte: YEAR_BEFORE, $lte: TODAY }
      }
  },
  { 
      $group: {
          _id: { "year_month": { $substrCP: [ "$created_at", 0, 7 ] } }, 
          count: { $sum: 1 }
      } 
  },
  {
      $sort: { "_id.year_month": 1 }
  },
  { 
      $project: { 
          _id: 0, 
          count: 1, 
          month_year: { 
              $concat: [ 
                 { $arrayElemAt: [ monthsArray, { $subtract: [ { $toInt: { $substrCP: [ "$_id.year_month", 5, 2 ] } }, 1 ] } ] },
                 "-", 
                 { $substrCP: [ "$_id.year_month", 0, 4 ] }
              ] 
          }
      } 
  },
  { 
      $group: { 
          _id: null, 
          data: { $push: { k: "$month_year", v: "$count" } }
      } 
  },
  { 
      $addFields: { 
          start_year: { $substrCP: [ YEAR_BEFORE, 0, 4 ] }, 
          end_year: { $substrCP: [ TODAY, 0, 4 ] },
          months1: { $range: [ { $toInt: { $substrCP: [ YEAR_BEFORE, 5, 2 ] } }, { $add: [ LAST_MONTH, 1 ] } ] },
          months2: { $range: [ FIRST_MONTH, { $add: [ { $toInt: { $substrCP: [ TODAY, 5, 2 ] } }, 1 ] } ] }
      } 
  },
  { 
      $addFields: { 
          template_data: { 
              $concatArrays: [ 
                  { $map: { 
                       input: "$months1", as: "m1",
                       in: {
                           count: 0,
                           month_year: { 
                               $concat: [ { $arrayElemAt: [ MONTHS_ARRAY, { $subtract: [ "$$m1", 1 ] } ] }, "-",  "$start_year" ] 
                           }                                            
                       }
                  } }, 
                  { $map: { 
                       input: "$months2", as: "m2",
                       in: {
                           count: 0,
                           month_year: { 
                               $concat: [ { $arrayElemAt: [ MONTHS_ARRAY, { $subtract: [ "$$m2", 1 ] } ] }, "-",  "$end_year" ] 
                           }                                            
                       }
                  } }
              ] 
         }
      }
  },
  { 
      $addFields: { 
          data: { 
             $map: { 
                 input: "$template_data", as: "t",
                 in: {   
                     k: "$$t.month_year",
                     v: { 
                         $reduce: { 
                             input: "$data", initialValue: 0, 
                             in: {
                                 $cond: [ { $eq: [ "$$t.month_year", "$$this.k"] },
                                              { $add: [ "$$this.v", "$$value" ] },
                                              { $add: [ 0, "$$value" ] }
                                 ]
                             }
                         } 
                     }
                 }
              }
          }
      }
  },
  {
      $project: { 
          data: { $arrayToObject: "$data" }, 
          _id: 0 
      } 
  }
] )
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输出:

{
        "data" : {
                "April-2019" : 0,
                "May-2019" : 1,
                "June-2019" : 0,
                "July-2019" : 0,
                "August-2019" : 0,
                "September-2019" : 0,
                "October-2019" : 0,
                "November-2019" : 0,
                "December-2019" : 0,
                "January-2020" : 1,
                "February-2020" : 2,
                "March-2020" : 0,
                "April-2020" : 1
        }
}
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