javascript - Mongoose 使用数字类型自动减少字段

Question

我目前在我的项目中使用了猫鼬，这是我的架构：

const mongoose = require('mongoose');
const classSchema = mongoose.Schema({
  _id: mongoose.Schema.Types.ObjectId,
  consultant: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Consultant',
    required: true,
  },
  faculty: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Faculty',
    required: true,
  },
  startYear: {
    type: String,
    required: true,
  },
  currentSchoolYear: {
    type: String,
    required: true,
  },
  currentSemester: {
    type: String,
    required: true,
  },
  classname: {
    type: String,
    required: true,
    unique: true,
  },
  classSize: {
    type: Number,
    required: true,
  },
  warnedLength: {
    type: Number,
    required: true,
  },
});

const Class = mongoose.model('Class', classSchema);

module.exports = Class;

如您所见，我有 2 个属性classSize，它们warnedLength分别是 Number。现在我想做一个功能，当我点击客户端的按钮时，classSize和的值warnedLength会自动减1。有没有办法做到这一点，非常感谢你的帮助，这对我来说意义重大，祝你有美好的一天

标签： javascriptdatabasemongooseautomationbackend