核心代码：

js代码

var Lesson = Schema({ 
  lessonName: String, 
  intr: String, 
  creTime: Date, 
  sort: String, //分类 
  imgUrl: String, //封面地址 
  price: Number, 
  teacher: String,//教师 
  subTitle:[{ 
    lNo: Number, 
    subLName: String, 
    src: String, 
    filtered: {type: Boolean, default: false} 
    }] 
});