text: const mongoose = require('mongoose')
  
  //将mongoose.Schema 赋值给一个变量
  var Schema = mongoose.Schema;
  
  //创建Schema（模式）对象
  var stuSchema = new Schema({
  	name:String,
  	age:Number,
  	gender:{
  		type:String,
  		default:"female"  // 设置默认值
  	},
  	address:String
  });
  
  // 发布模型，''里的名字要和表中一模一样
  let student = mongoose.model("student" , stuSchema);
  module.exports = student