node.js - Mongoose-如何引用嵌入文档元素？

Question

我有 users.js 架构，其中包含嵌入文档数组 pets。对于每个用户，一个用户可以拥有多个宠物(我认为通常不超过 3 个)。

对于每只宠物，都会有一个每日图表。所以对于一只宠物来说会有很多每日图表。我读过嵌入式文档，每个数组元素都有索引。在 daily.js 中，如何为 populate() 函数引用它所属的宠物？

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var userSchema = new Schema({
    firstName: { type: String, required: true },
    lastName: { type: String, required: true },
    username: { type: String, required: true, unique: true },
    location: String,
    pets: [{ name: 'string', animalType: 'string'}], //could have more than one pet
    created_at: Date,
    updated_at: Date
});

---

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var dailySchema = new Schema({
  tite: String,
  _pet: { type: Number, ref: 'User.pet' }, // not sure how to reference name in user.pets[#] array
  created_at: Date,
  updated_at: Date
});

Answer 1

Quoting

Sorry to disappoint but that is an anti-pattern. Populate can't populate from another collection's subdocs - the reason why you're getting that error is that there's no model for boards.

因此，引用嵌入文档可能不是一个好的模式。最好将 pet 与 User 分离为一个架构

var PetSchema = new Schema ({ 
    name: 'string', 
    animalType: 'string'
});

UserSchema 和 DailySchema 将是

var userSchema = new Schema({
    ...
    pets: [{ type: Schema.Types.ObjectId, ref: 'Pet' }], //could have more than one pet
});

var dailySchema = new Schema({
  _pet: { type: Number, ref: 'Pet' }, // not sure how to reference name in user.pets[#] array
});