Javascript 在mongo中使用$sum和$cond获取$sum值，而不是实例总数

我尝试使用$group和$project操作符的组合，除非有更好的替代方法来生成两个值

考虑如下所示的文档数据结构：

[
  {
    _id: 1,
    openBalance: 22,
    customerResponsible: true
  },
  {
    _id: 2,
    openBalance: 16,
    customerResponsible: false
  },
  {
    _id: 3,
    openBalance: 10,
    customerResponsible: true
  },
  {
    _id: 4,
    openBalance: 20,
    customerResponsible: false
  },
]

我要做的是输出一个值为customerOpenBalance的文档，它表示customerResponsible为true的文档的总openBalance。以及一个值agencyOpenBalance，它表示customerResponsible设置为false的总openBalance

现在，我可以在$group阶段执行此操作：

然后在稍后的$project阶段执行以下操作：

"customerResponsibleOpenBalance" : { "$sum": "$customerResponsibleOpenBalance" }

但这给了我实例的$sum，而不是我实际想要的，openBalance中的$sum值，其中，对于CustomerResponsiblePenbalance，我所针对的布尔值customerResponsible是真的

如何调整此聚合以获得$openBalance中的$sum值，而不是实例的$sum值

我的完整聚合管道如下所示。关键阶段是第6阶段的$group，以及第18阶段的$project：

db.transactions.aggregate

  // Pipeline
  [
    // Stage 1
    {
      $match: {
        "openBalance": {
          "$ne": 0.0
        }
      }
    },

    // Stage 2
    {
      $lookup: {
        "from": "customers",
        "localField": "customer.id",
        "foreignField": "_id",
        "as": "customer"
      }
    },

    // Stage 3
    {
      $unwind: {
        "path": "$customer"
      }
    },

    // Stage 4
    {
      $lookup: {
        "from": "visits",
        "localField": "visit.id",
        "foreignField": "_id",
        "as": "visit"
      }
    },

    // Stage 5
    {
      $unwind: {
        "path": "$visit"
      }
    },

    // Stage 6
    {
      $group: {
        "_id": "$customer._id",
        "submissions": {
          "$push": "$submissions"
        },
        "staffMember": {
          "$first": "$staffMember.id"
        },
        "visit": {
          "$first": "$visit"
        },
        "openBalance": {
          "$sum": "$openBalance"
        },
        "customerResponsibleOpenBalance": {
          "$sum": {
            "$cond": ["$visit.customerResponsibility", 1, 0]
          }
        },
        "agencyResponsibleOpenBalance": {
          "$sum": {
            "$cond": ["$visit.customerResponsibility", 0, 1]
          }
        },
        "openClaims": {
          "$sum": {
            "$cond": {
              "if": {
                "$gt": ["$submissions.0.responses.balance", 0.0]
              },
              "then": 1.0,
              "else": 0.0
            }
          }
        }
      }
    },

    // Stage 7
    {
      $addFields: {
        "payerInfo": "$submissions.0.details.agency._id"
      }
    },

    // Stage 8
    {
      $lookup: {
        "from": "agencies",
        "localField": "submissions.0.details.agency._id",
        "foreignField": "_id",
        "as": "agency"
      }
    },

    // Stage 9
    {
      $unwind: {
        "path": "$agency"
      }
    },

    // Stage 10
    {
      $addFields: {
        "claimSupervisor": "$agency.claims.supervisor"
      }
    },

    // Stage 11
    {
      $lookup: {
        "from": "staffmembers",
        "localField": "claimSupervisor",
        "foreignField": "_id",
        "as": "claimSupervisor"
      }
    },

    // Stage 12
    {
      $unwind: {
        "path": "$claimSupervisor"
      }
    },

    // Stage 13
    {
      $lookup: {
        "from": "customers",
        "localField": "_id",
        "foreignField": "_id",
        "as": "customer"
      }
    },

    // Stage 14
    {
      $unwind: {
        "path": "$customer"
      }
    },

    // Stage 15
    {
      $lookup: {
        "from": "locales",
        "localField": "customer.locale",
        "foreignField": "_id",
        "as": "locale"
      }
    },

    // Stage 16
    {
      $unwind: {
        "path": "$locale"
      }
    },

    // Stage 17
    {
      $lookup: {
        "from": "agencies",
        "localField": "agencies",
        "foreignField": "_id",
        "as": "agencies"
      }
    },

    // Stage 18
    {
      $project: {
        "customer": {
          "_id": 1.0,
          "name": 1.0
        },
        "agency": {
          "_id": 1.0,
          "name": 1.0,
          "transactionType": 1.0
        },
        "visit": {
          "_id": 1.0,
          "customerResponsibility": 1.0
        },
        "openBalance": 1.0,
        "openClaims": 1.0,
        "customerResponsibleOpenBalance": {
          "$sum": "$customerResponsibleOpenBalance"
        },
        "agencyResponsibleOpenBalance": {
          "$sum": "$agencyResponsibleOpenBalance"
        },
        "locale": {
          "_id": 1.0,
          "name": 1.0
        },
        "firstSubmission": {
          "$arrayElemAt": ["$submissions", 0.0]
        },
        "lastSubmission": {
          "$arrayElemAt": ["$submissions", -1.0]
        },
        "claimSupervisor": {
          "_id": 1.0,
          "name": 1.0
        }
      }
    },

    // Stage 19
    {
      $unwind: {
        "path": "$firstSubmission"
      }
    },

    // Stage 20
    {
      $unwind: {
        "path": "$lastSubmission"
      }
    },

    // Stage 21
    {
      $project: {
        "firstSubmission": {
          "details": 0.0,
          "responses": 0.0
        },
        "lastSubmission": {
          "details": 0.0,
          "responses": 0.0
        }
      }
    },
  ],

);

---

对不起，一开始我被你的样本数据误导了。现在，有了经过编辑的问题和完整的管道，我想你只需要从

"customerResponsibleOpenBalance" : { "$sum" : { "$cond" : [ "$customerResponsibile", 1, 0 ] }}

到

---

这将为customerResponsible为true时获得一个值，但我还需要customerResponsible为false时的值。我该怎么做？错了两次；请查看更新的答案，其中解释了这里发生的事情。是的。请参见此处的示例：。还可以看到我的更新答案。啊，这样你就可以把数组传递给$cond了。我没有意识到。只需交换if和else位：customerResponsibleOpenBalance:{$sum:{$cond:[$customerResponsibile:0，$openBalance]}我有一种感觉，在管道中有很多事情不太对劲。如果您可以发布一些匹配的样本数据与所需的输出，我相信我们可以得到这个权利为您。

"customerResponsibleOpenBalance" : { "$sum" : { "$cond" : [ "$customerResponsibile", 1, 0 ] }}

"customerResponsibleOpenBalance" : { "$sum" : { "$cond" : [ "$customerResponsibile", "$openBalance", 0 ] }},