Mongoose populate方法

Question

我在尝试让mongoose中的populate功能工作时遇到了最大的麻烦。我已经查看了SO上的所有主题，没有任何帮助。我的架构在下面列出。

'use strict';

/**
 * Module dependencies.
 */
var mongoose = require('mongoose'),
  Schema = mongoose.Schema;


/**
 * Prodcut Feature Extra
 */
var extra = new Schema({
  name: {
    type: String,
    default: '',
    required: 'Please fill Product name',
    trim: true
  },
  price: {
    type: Number,
    default: 0
  },
  description: {
    type: String,
    trim: true
  },
  toolTip: {
    type: String,
    trim: true,
    min: 3,
    max: 140
  },
  created: {
    type: Date,
    default: Date.now
  },
  user: {
    type: Schema.ObjectId,
    ref: 'User'
  }
});

/**
 * Product Feature Schema
 */
var feature = new Schema({
  name: {
    type: String,
    default: '',
    required: 'Please fill feature name',
    trim: true
  },
  created: {
    type: Date,
    default: Date.now
  },
  user: {
    type: Schema.ObjectId,
    ref: 'User'
  }
});

/**
 * Product Schema
 */
var ProductSchema = new Schema({
  name: {
    type: String,
    default: '',
    required: 'Please fill Product name',
    trim: true
  },
  created: {
    type: Date,
    default: Date.now
  },
  features: [feature],
  extras: [extra],
  user: {
    type: Schema.ObjectId,
    ref: 'User'
  }
});

mongoose.model('Feature', feature);
mongoose.model('Extra', extra);
mongoose.model('Product', ProductSchema);

我在Mongoose Repl中尝试了以下所有查询，但没有任何作用

＆＃13;

＆＃13;

 models.Product.find().populate("Extra", "name").exec()
 models.Product.find().populate({path: "extras", location: "Extra"}).exec()
 models.Product.find().populate('extras', 'name').exec()
 models.Product.find().populate('extras', 'Extra').exec()

＆＃13;

＆＃13;

＆＃13;

有没有人有任何建议？这是杀了我!!

Answer 1

好奇！

下面的初始化，是否必须在ProductSchema中引用之前完成？

mongoose.model('Feature', feature);
mongoose.model('Extra', extra);

像这样的东西

mongoose.model('Feature', feature);
mongoose.model('Extra', extra);

var ProductSchema = new Schema({
name: {
 type: String,
 default: '',
 required: 'Please fill Product name',
 trim: true
},
created: {
  type: Date,
  default: Date.now
},
features: [ {
  type: Schema.ObjectId,
  ref: 'Feature'
}],
extras: [ {
  type: Schema.ObjectId,
  ref: 'Extra'
}],
user: {
  type: Schema.ObjectId,
  ref: 'User'
}
});

这应该可行

models.Product.find().populate("extras")