Node.js 如何在mongoose中连接两个模型？

我做了这两个模型，我不知道如何在食物和使用者之间建立联系

模式1：

const mongoose = require('mongoose');
const passportLocalMongoose = require('passport-local-mongoose');


var UserSchema = new mongoose.Schema({
    username: String,
    password: String,
    repassword: String,
    email: String

})

UserSchema.plugin(passportLocalMongoose);

module.exports = mongoose.model("User", UserSchema);

模式2：

var mongoose = require('mongoose');


var foodSchema = new mongoose.Schema({
   name: String,
   image: String,
   notify: String,
   createdAt: {type: Date, default: Date.now},
    author: {
      id: {
         type: mongoose.Schema.Types.ObjectId,
         ref: "User"
      },
      username: String
   },
});


   module.exports = mongoose.model("food", foodSchema);

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要查询出数据，您可以尝试

填充
可能重复的