Node.js 基于分组的$sum在sum字段的mongodb rathar重新分组中未获得正确的sum？

我有几个系列，我想从中获得前六大畅销品牌

收藏品： //这就是mongodb atlas上的外观

收款顺序：

//这就是mongodb atlas上的外观

收款单\产品\枢轴：

//这就是mongodb atlas上的外观

品牌系列：

这是我为这个问题编写的代码，但是它基于sum字段重新组合，而不是给我sum

   const join = OrderProductPivot.aggregate([
      {
        $lookup: {
            from: "products",
            localField: "productId",
            foreignField: "_id",
            as: "TheProduct"
        }
    },
    {
        $unwind: "$TheProduct"
    },
    {
        $lookup: {
            from: "brands",
            localField: "TheProduct.belongsToBrand",
            foreignField: "_id",
            as: "TheBrand"
        }
    },
    {
        $unwind: "$TheBrand"
    },
    {
        $project: {
            '_id': 1,
            'TheProduct.belongsToBrand': 1,
            'TheBrand.name': 1,
            'quantityPurchased': 1,
            'productId': 1,
            // 'shortDescription': 1,
            // 'createdAt': 1,
            // 'AddedBy.username': 1,
        }
    },
    {
        $group: {
            _id: {
                "_id": "$TheProduct.belongsToBrand",
                "name": "$TheBrand.name",
                "total": {
                    $sum: "$quantityPurchased"
                },
              
            },
            products: { $push: "$$ROOT" }
        }
    }

]);

join.exec((err, res) => {
    if (err) return callback({
        status: process.env.SERVER_ERROR_CODE,
        message: err.message
    });

    callback({
        status: process.env.SUCCESS_CODE,
        data: res
    });
});

我现在得到的结果示例：

    {
    "status": "200",
    "data": [
        {
            "_id": {
                "_id": null,
                "total": {
                    "$numberDecimal": "2"
                }
            },
            "products": [
                {
                    "_id": "5f5a2d1e6130d73820358a81",
                    "productId": "5f5266b37f32df29c5f0488e",
                    "quantityPurchased": {
                        "$numberDecimal": "2"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f4651532f6fae13ac5d8a18"
                    },
                    "TheBrand": {
                        "name": "Apple"
                    }
                },
                {
                    "_id": "5f5a2d1e6130d73820358a82",
                    "productId": "5f5266b37f32df29c5f0488f",
                    "quantityPurchased": {
                        "$numberDecimal": "2"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f4651532f6fae13ac5d8a18"
                    },
                    "TheBrand": {
                        "name": "Apple"
                    }
                }
            ]
        },
        {
            "_id": {
                "_id": null,
                "total": {
                    "$numberDecimal": "1"
                }
            },
            "products": [
                {
                    "_id": "5f5a24bf6130d73820358a74",
                    "productId": "5f57d8632bdc2470827c12f2",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a24bf6130d73820358a75",
                    "productId": "5f58a96a42fe8c168e4e47d8",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a24bf6130d73820358a76",
                    "productId": "5f58bd6142fe8c168e4e47f7",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f4651532f6fae13ac5d8a18"
                    },
                    "TheBrand": {
                        "name": "Apple"
                    }
                },
                {
                    "_id": "5f5a24bf6130d73820358a77",
                    "productId": "5f58c1f442fe8c168e4e47fc",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f4651532f6fae13ac5d8a18"
                    },
                    "TheBrand": {
                        "name": "Apple"
                    }
                },
                {
                    "_id": "5f5a2ca96130d73820358a7a",
                    "productId": "5f58a96a42fe8c168e4e47d8",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2ca96130d73820358a7b",
                    "productId": "5f57d8632bdc2470827c12f2",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2ca96130d73820358a7c",
                    "productId": "5f58aa5e42fe8c168e4e47d9",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2ca96130d73820358a7d",
                    "productId": "5f58ab9642fe8c168e4e47da",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2ca96130d73820358a7e",
                    "productId": "5f58af2742fe8c168e4e47db",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2ca96130d73820358a7f",
                    "productId": "5f58b97842fe8c168e4e47f2",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2d1e6130d73820358a83",
                    "productId": "5f5283e5bb2e474606413c51",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2d1e6130d73820358a84",
                    "productId": "5f528711bb2e474606413d0b",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2d1e6130d73820358a85",
                    "productId": "5f5283e1bb2e474606413c50",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2d1e6130d73820358a86",
                    "productId": "5f52874abb2e474606413d19",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2d1e6130d73820358a87",
                    "productId": "5f52874abb2e474606413d32",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2d1e6130d73820358a88",
                    "productId": "5f52874abb2e474606413d33",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f463416cfd44876a5e96f5e"
                    },
                    "TheBrand": {
                        "name": "Samsung"
                    }
                },
                {
                    "_id": "5f5a2ddb6130d73820358a8a",
                    "productId": "5f5266b37f32df29c5f0488e",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f4651532f6fae13ac5d8a18"
                    },
                    "TheBrand": {
                        "name": "Apple"
                    }
                },
                {
                    "_id": "5f5a2ddb6130d73820358a8b",
                    "productId": "5f5266b37f32df29c5f0488f",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f4651532f6fae13ac5d8a18"
                    },
                    "TheBrand": {
                        "name": "Apple"
                    }
                },
                {
                    "_id": "5f5a2e776130d73820358a8d",
                    "productId": "5f5266b37f32df29c5f0488e",
                    "quantityPurchased": {
                        "$numberDecimal": "1"
                    },
                    "TheProduct": {
                        "belongsToBrand": "5f4651532f6fae13ac5d8a18"
                    },
                    "TheBrand": {
                        "name": "Apple"
                    }
                }
            ]
        }
    ]
}

---

如果您提供在mongo shell中创建数据的示例insert命令，然后在您尝试使用的mongo shell中提供聚合命令，那么这个问题将更容易理解。并删除与mongoose/js有关的所有内容。我正在尝试按组获取和，但不是获取和。我的聚合方法是基于重新分组的在property QuantityPurchased上，

total

字段不应位于

$group

阶段的

\U id

内。谢谢@Joe，请将您的评论作为答案发布，以便我检查。这对我有用