是否可以在地图架构类型中填充对象? [英] Is it possible to populate objects in map schema type?

问题描述

我的猫鼬模型中有模式类型 Map.在此映射中，每个元素都引用了另一个模型.我知道可以在数组中填充属性，但是Map类型呢?导致像"map_type_attribute.some_attribute_to_populate"这样的嵌套；不起作用.:)

I have schema type Map in my mongoose model. In this map, each element has reference to another model. I know that it's possible to populate attributes in array, but how about Map type? Be cause nesting like "map_type_attribute.some_attribute_to_populate" doesn't work. :)

这是我的模特

const Mongoose = require('mongoose');

const parameter = Mongoose.Schema({
  definition: {
    type: Mongoose.Schema.Types.ObjectId,
    ref:  'Definition',
  },
  value:      {},
}, {_id: false});

const schema = Mongoose.Schema({
  model:      {
    type: Mongoose.Schema.Types.ObjectId,
    ref:  'Model'
  },
  name:       String,
  objectid:   Number,
  externalId: String,
  properties: Mongoose.Schema.Types.Mixed,
  parameters: {
    type: Map,
    of:   parameter
  }
});

module.exports = Mongoose.model('Element', schema);

这是我尝试填充定义字段的方式:

This is how i'm trying to populate definition field:

 const request = Element.find(query, projection);
  request.populate('parameters.definition');
  request.exec( (err, docs) => {
...

推荐答案

此功能已已添加(猫鼬5.10.3)(2020年9月).您只需用 $ * 表示地图中的每个元素.

This functionality was added in Mongoose 5.10.3 (September 2020). You simply denote every element in the map with a $*.

在您的示例中，这将是:

In your example this would be:

  const request = Element.find(query, projection);
  request.populate('parameters.$*.definition');
  request.exec( (err, docs) => {

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