Mongo数据库根据时间戳查询许多集合，并对查询结果进行分组和排序

Question

我正在进行小型社交网络项目Node / Express / Mongodb / Mongoose。我有一些带有嵌套文档和引用的架构。例如，一个用户可以发帖，另一个用户可以在该帖子下发表评论。我想查询所有集合并将结果按从新到旧的顺序排序。我需要一个用户供稿。用于显示系统中的最新活动。

相关架构

 
const UserSchema = new mongoose.Schema({
  name: {
    type: String,
    required: true,
  },
  email: {
    type: String,
    required: true,
    unique: true,
  },
  password: {
    type: String,
    required: true,
  },
  approved: {
    type: Boolean,
    required: true,
    default: false,
  },
  payment: {
    type: Boolean,
    default: false,
  },
  emailApproved: {
    type: Boolean,
    default: false,
  },
  paymentDate: {
    type: Date,
  },
  resetToken: String,
  resetTokenExpiration: Date,
  emailToken: {
    type: String,
  },
  following: [{ type: mongoose.Schema.Types.ObjectId, ref: "user" }],
  followers: [{ type: mongoose.Schema.Types.ObjectId, ref: "user" }],
  role: {
    type: String,
    required: true,
    default: "user",
    enum: ["user", "admin", "root", "commission"],
  },
  date: {
    type: Date,
    default: Date.now,
  },
});
 

const ProfileSchema = new mongoose.Schema(
  {
    user: {
      type: mongoose.Schema.Types.ObjectId,
      ref: "user",
    },
    image: {
      type: String,
    },
    company: {
      type: String,
    },
    website: {
      type: String,
    },
    start: {
      type: Number,
      required: true,
    },
    graduation: {
      type: Number,
      required: true,
    },
    department: {
      type: String,
      required: true,
    },
    option: {
      type: String,
      required: true,
    },
    product: {
      type: String,
      required: true,
    },
    mentorship: {
      type: Boolean,
    },
    scholarship: {
      type: Boolean,
    },
    mentorshipSeeker: {
      type: Boolean,
    },
    work: {
      type: Boolean,
    },
    workSeeker: {
      type: Boolean,
    },
    sponsorship: {
      type: Boolean,
    },
    sponsorshipSeeker: {
      type: Boolean,
    },
    internship: {
      type: Boolean,
    },
    scholarshipSeeker: {
      type: Boolean,
    },
    internshipSeeker: {
      type: Boolean,
    },
    representative: {
      type: Boolean,
    },
    location: {
      type: String,
    },
    status: {
      type: String,
      required: true,
    },
    skills: {
      type: [String],
      required: true,
    },
    boardMember: {
      type: Boolean,
    },
    bio: {
      type: String,
    },
    description: {
      type: String,
    },
    phone: {
      type: String,
      required: true,
    },
    emailWork: {
      type: String,
    },

    showPhone: {
      type: Boolean,
      required: true,
      default: false,
    },
    member: {
      type: Boolean,
    },
    payment: {
      type: Boolean,
    },

    signed: {
      type: Boolean,
    },

    schoolRelation: {
      type: String,
    },

    experience: [
      {
        title: {
          type: String,
          required: true,
        },
        company: {
          type: String,
          required: true,
        },
        location: {
          type: String,
        },
        from: {
          type: Date,
          required: true,
        },
        to: {
          type: Date,
        },
        current: {
          type: Boolean,
          default: false,
        },
        description: {
          type: String,
        },
      },
    ],
    education: [
      {
        school: {
          type: String,
          required: true,
        },
        degree: {
          type: String,
          required: true,
        },
        fieldofstudy: {
          type: String,
          required: true,
        },
        from: {
          type: Date,
          required: true,
        },
        to: {
          type: Date,
        },
        current: {
          type: Boolean,
          default: false,
        },
        description: {
          type: String,
        },
      },
    ],
    social: {
      youtube: {
        type: String,
      },
      twitter: {
        type: String,
      },
      facebook: {
        type: String,
      },
      linkedin: {
        type: String,
      },
      instagram: {
        type: String,
      },
    },
    date: {
      type: Date,
      default: Date.now,
    },
  },
  { timestamps: true }
);

const PostSchema = new Schema(
  {
    activity: {
      type: Schema.Types.ObjectId,
      ref: "activity",
      unique: true,
      index: true,
      sparse: true,
    },
    group: {
      type: Schema.Types.ObjectId,
      ref: "group",
      unique: true,
      index: true,
      sparse: true,
    },
    user: {
      type: Schema.Types.ObjectId,
      ref: "user",
    },
    text: {
      type: String,
      required: true,
    },
    name: {
      type: String,
    },
    image: {
      type: String,
    },
    likes: [
      {
        user: {
          type: Schema.Types.ObjectId,
          ref: "user",
        },
         date: {
          type: Date,
          default: Date.now,
        },
      },
    ],
    comments: [
      {
        user: {
          type: Schema.Types.ObjectId,
          ref: "user",
        },
        text: {
          type: String,
          required: true,
        },
        name: {
          type: String,
        },
        avatar: {
          type: String,
        },
        date: {
          type: Date,
          default: Date.now,
        },
      },
    ],
    date: {
      type: Date,
      default: Date.now,
    },
  },
  { timestamps: true }
);

我想查询所有模式，包括嵌套模式。然后将它们排序在新文档中。

例如

{latest activity:[

{ 
comment:{
_id:345345098203948209423409,
user:345345345345345,
text:loremipsum,
date:28/6/2020
postId:4350394583049545
},
{
like:{
_id:23402394802934820394
user:3459803948509348503945
postId:2323409283409238409234
date:27/06/2020
}
},
{
profile:{
_id:2234234234234,
user:2340293840293842093,
date:25/06/2020
}

}]
}

我可以通过服务器端javascript执行。 但是我正在寻找一种通过mongoose / mongo查询实现它的方法。任何帮助将不胜感激

谢谢