我怎样才能得到 mongoDB 的总和 属性

Question

我有一个带有 属性 UserTo 的对象数组，每个对象都有 属性 Amount，我想添加所有具有相同 UserTo 的用户数量，我如何在 mongoDB 或 javaScript。正如您在下面的数组中看到的那样，其中许多具有相同的 UserTo 并且每个都有不同的金额，所以我想将它们的所有金额与总金额相加在一个文档中并删除重复项

代码：

(4) [{…}, {…}, {…}, {…}]
0:
Amount: 5
CoinpackPurchasedID: "617f96255c47518b6741893c"
Level: 1
Status: "Active"

UserTo: "617f8d255c47518b674188c9"
created_at: "2021-11-01T07:24:36.962Z"
updated_at: "2021-11-01T07:24:36.962Z"
__v: 0
_id: "617f96345c47518b6741894b"
[[Prototype]]: Object


1:
Amount: 5
CoinpackPurchasedID: "617f96255c47518b6741893c"
Level: 1
Status: "Active"

UserTo: "617f8d255c47518b674188c9"
created_at: "2021-11-01T07:24:36.962Z"
updated_at: "2021-11-01T07:24:36.962Z"
__v: 0
_id: "6186558fec66b04ecb6892ce"
[[Prototype]]: Object
2:
Amount: 5
CoinpackPurchasedID: "617f96255c47518b6741893c"
Level: 1
Status: "Active"

UserTo: "617f8d255c47518b674188c9"
created_at: "2021-11-01T07:24:36.962Z"
updated_at: "2021-11-01T07:24:36.962Z"
__v: 0
_id: "61867816329e07487e91ea9b"
[[Prototype]]: Object


3:
Amount: 10
CoinpackPurchasedID: "617f96255c47518b6741893c"
Level: 2
Status: "Active"

UserTo: "617f8c9d5c47518b674188ba"
created_at: "2021-11-01T07:24:36.963Z"
updated_at: "2021-11-01T07:24:36.963Z"
__v: 0
_id: "617f96345c47518b6741894c"
[[Prototype]]: Object

Answer 1

使用$group

db.collection.aggregate([
  {
    "$group": {
      "_id": "$UserTo",
      "sum": {
        "$sum": "$Amount"
      }
    }
  }
])

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