Mongodb 需要帮助聚合猫鼬数据吗

我有一个MERN堆栈应用程序，当我进行GET调用时，我希望返回所有MongoDB对象的投票

这就是我的对象的外观：

{_id: ObjectId("6092d48d96984d233cf77152")
user: "John Doe"
movies: [
     0:
          _id: ObjectId("6092b19345f48a33447468a7"),
          title: "Alpha",
          ranking: 3
     1:
          _id: ObjectId("6092b19345f48a33447468a7"),
          title: "Bravo",
          ranking: 2
     2:
          _id: ObjectId("6092b19345f48a33447468a7"),
          title: "Charlie",
          ranking: 1
]}

{_id: ObjectId("6092d48d96984d233cf77152")
user: "John Doe"
movies: [
     0:
          _id: ObjectId("6092b19345f48a33447468a7"),
          title: "Alpha",
          ranking: 3
     1:
          _id: ObjectId("6092b19345f48a33447468a7"),
          title: "Bravo",
          ranking: 2
     2:
          _id: ObjectId("6092b19345f48a33447468a7"),
          title: "Charlie",
          ranking: 1
]}

显然会有更多的数据，但基本上我希望返回：

[{title: "Alpha", ranking: 6},
{title: "Bravo", ranking: 4},
{title: "Charlie", ranking: 2}]

我假设我必须使用

$match

函数，但这是我第一次这样使用Mongoose/MongoDB。提前谢谢

• $unwind

  deconstruct

  movies

  array

• $group

  by

  movies.title

  和sum

  排名

---

太好了，非常感谢！我知道电影阵列有些奇怪

let result = await YourModelName.aggregate([ // replace your model name
  { $unwind: "$movies" },
  {
    $group: {
      _id: "$movies.title",
      ranking: { $sum: "$movies.ranking" }
    }
  }
])