Mongo数据库
我想根据图中所示的数据库在节点js中创建数据模型（Schema）。如何在节点js中创建数组的数据模型，以及数组内部的对象，其中还包含另一个数组？
const mongoose = require('mongoose');
mongoose.pluralize(null);
const Schema = mongoose.Schema;
const indicatorsSchema = new Schema({
name:String,
metrics:[String] //[String] define array of string
}, { _id: false });
const Learning = new Schema({
learningEvents: String,
learningActivities: [String], //[String] define array of string
indicators:[indicatorsSchema] // define object as above
}, { versionKey: false })
