如何使用mongo比较值和分组？

如何解决如何使用mongo比较值和分组？

我正在尝试检查两个日期是否相等，然后根据日期对另一个结果进行分组。

{"creationDate": "2021/3/19","_id": "60549366ab4eb00aa1ed2fd9","avgPower": 8241,"WaterConsumption": 22},{"creationDate": "2021/3/19","_id": "605493f4ab4eb00aa1ed2fda",{"creationDate": "2021/2/17","_id": "60549433ab4eb00aa1ed2fdb","avgPower": 4300,"WaterConsumption": 32,}

我能够使用如下例所示的字符串进行聚合。这是我所能进行的最远的聚合。

let dateTwo = await Measure.aggregate([
  {$match: {creationDate: "2021/3/19"}},<=======
  {$group: {_id: "$user",total: {$sum: "$WaterConsumption"}}}
]);

代码应该做什么：

let dateTwo = await Measure.aggregate([
  {$match: {creationDate: ==>Check if the dates are equal<==}},{$group: {_id: "$user",total: {$sum: "$WaterConsumption"}}}
]);

预期结果

{"creationDate": "2020/3/19","_id": "someID","WaterConsumption": 44}

如何声明一个表达式来检查 creationDates 是否相等？我真的很挣扎。我可以使用 JavaScript 做到这一点，但我不知道如何使用 mongo 做到这一点。

解决方法

希望这就是您想要弄清楚的。如果不是，请尝试重新表述您的问题。

MongoPlayground

db.collection.aggregate({
  $match: {
    creationDate: "2021/3/19"
  }
},{
  $group: {
    _id: "$creationDate",ids: {
      $push: "$_id"
    },total: {
      $sum: "$WaterConsumption"
    }
  }
},{
  $project: {
    "creationDate": "$_id","_id": "$ids","WaterConsumption": "$total"
  }
})

,

我使用以下行解决了问题：

    let dateTwo = await Measure.aggregate([
        {$group: {_id: {creationDate: "$creationDate"},total: {$sum: "$WaterConsumption"}}}
    ])