Node Mongoose虚拟属性返回下级匹配条件

const mongoose = require('mongoose');

// 定义子文档模型
const ChildSchema = new mongoose.Schema({
  name: String,
  age: Number
});

// 定义父文档模型
const ParentSchema = new mongoose.Schema({
  name: String,
  children: [ChildSchema]
});

// 定义虚拟属性
ParentSchema.virtual('matchingChildren', {
  ref: 'Child',
  localField: '_id',
  foreignField: 'parentId',
  justOne: false,
  options: { age: { $gt: 10 } }
});

// 创建模型
const Parent = mongoose.model('Parent', ParentSchema);
const Child = mongoose.model('Child', ChildSchema);

// 查询父文档并返回满足条件的子文档
Parent.findById(parentId)
  .populate('matchingChildren')
  .exec((err, parent) => {
    if (err) {
      console.error(err);
    } else {
      console.log(parent.matchingChildren);
    }
  });