如何通过isDisliked字段为false的位置填充用户id

Question

我需要通过isDisliked为false的位置填充来自likedBy的用户，请找到文档架构。

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我正在使用下面的查询，但无法填充用户。使用下面的查询，

let likedBy = await StoryComment.aggregate([{"$match":{"_id": exportLib.ObjectId(currentPost)}}, {"$match":{"comments.likedBy.isDisliked": false}}]);

获取如下所示的输出

[
  {
    _id: 60fd5b5336a2780754021ce0,
    comments: { reply: [], likedBy: [Array], report: [] },
    isDeleted: false,
    isArchived: false,
    storyId: 60fa45be78e0cc052760922f,
    comment: 'New to this place bro',
    userId: 60e7ce8e0812ba086dc16074,
    createdAt: 2021-07-25T12:38:43.427Z,
    updatedAt: 2021-07-25T13:46:28.728Z,
    __v: 0
  }
]

预期输出：

[
  {
    isDisliked: false,
    _id: 60fd5d08ddf94d07d0da9d57,
    likedBy: 60e7ce8e0812ba086dc16074
  },
  {
    isDisliked: false,
    _id: 60fd6b34fa5bdf06a743fc3c,
    likedBy: 60df550da01794081fc83762
  }
]

需要填充位置上的用户详细信息(就像我们简单地使用likedBy一样)，这只是likedBy数组的非结构化版本。

请在此处找到该架构：

const storyComments = new mongoose.Schema(
  {
    storyId: { type: schema.Types.ObjectId, ref: "stories" },
    comment: { type: String },
    userId: { type: schema.Types.ObjectId, ref: "Users" },
    comments: {
      reply: [{
        comment: { type: String },
        userId: { type: schema.Types.ObjectId, ref: "Users" },
      }],
      likedBy : [{
        likedBy: { type: schema.Types.ObjectId, ref: "Users" },
        isDisliked: { type: Boolean, default: false}
      }],
      report : [{
        reportedBy: { type: schema.Types.ObjectId, ref: "Users" },
        reason: { type: String },
        isReported: { type: Boolean, default: false },
        isAdminApproved: { type: Boolean, default: false },
        isCreatorApproved: { type: Boolean, default: false },
        creatorEmail: { type: String },
        tokenToApprove: { type: String, default: ""}
      }]
    },
    isDeleted: { type: Boolean, default: false },
    isArchived: { type: Boolean, default: false }
  },
  {
    timestamps: true,
  }
);

请帮我解决这个问题。谢谢

Answer 1

您可以尝试此操作来填充用户

const story = StoryComment.find({
          "_id": exportLib.ObjectId(currentPost),
          "comments.likedBy": {
            "$elemMatch": {
              "isDisliked": true
            }
          }
        },
        {
          "comments.likedBy.$": 1
        })
        .populate('Users')
        .exec(function (err, person) {
                if (err) return handleError(err);
                console.log(person);
        });

以下是官方文档的链接：Ref to childeren

或

如果你想通过aggregate管道来实现，你可以试试下面的代码

db.story.aggregate([
  {
    "$match": {
      "_id": ObjectId("5a934e000102030405000005")
    }
  },
  {
    "$unwind": "$comments.likedBy"
  },
  {
    "$match": {
      "comments.likedBy.isDisliked": false
    }
  },
  {
    "$project": {
      likedBy: "$comments.likedBy.likedBy"
    }
  },
  {
    "$lookup": {
      "from": "users",
      "localField": "likedBy",
      "foreignField": "_id",
      "as": "user"
    }
  },
  {
    "$unwind": "$user"
  },
  {
    $replaceRoot: {
      newRoot: "$user"
    }
  }
])

这里是游乐场的链接，用于测试您的用例：Mongo Playground