node.js - 使用nodejs在mongoose中保存嵌套文档时的错误处理

Question

我有两个模式:用户和回复。我引用了用户的回复。问题是我必须创建回复，然后将其推送到用户回复数组。如果创建回复后由于任何问题找不到用户怎么办？回复悬在空中，没有附加到任何用户。有什么解决办法吗？

回复架构:

const mongoose = require('mongoose');

const requestReplySchema = mongoose.Schema({
    email: String,
    answers: [
        {
            number: Number,
            title: String,
        }
    ]
}, {timestamps: true});

module.exports = mongoose.model('RequestReply', requestReplySchema);

用户架构(简化版):

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

const userSchema = mongoose.Schema({
    firstName: String,
    lastName: String,
    email: String,
    requestReplies: [
        {
            type: mongoose.Schema.Types.ObjectId,
            ref: 'RequestReply'
        }
    ]
}, {timestamps: true});

module.exports = mongoose.model('User', userSchema);

这部分的NodeJS代码:

let postReply = (req, res)=>{

    let replyAnswers = [];

    if(req.body.answers && (req.body.answers).length > 0){
        replyAnswers = req.body.answers;
    } else {
        return res.json({status: false, message: 'answers not properly formed'});
    }

    const newReply = {
        email: req.email,
        answers: replyAnswers,
    };

    RequestReply.create(newReply, (error, createdReply)=>{
        if(error || createdReply === null){
            return res.status(400).json({status: false, message: 'error getting data'})
        }

        User.findOne({email: req.email}, (error, foundUser)=>{
           if(error || foundUser === null){
               // what can I do here!? the request is saved, 
               // but the user is not found or and error happened
           }
        });
        return res.json({status: true})
    });
};

Answer 1

如果没有用户就无法存在回复，那么首先您必须找到该用户。如果不存在，则抛出错误，如果存在，则创建 Reply，然后将其附加到找到的用户。

User.findOne({email: req.email}, (error, foundUser)=>{
    if(error || foundUser === null){
        return res.status(400).json({status: false, message: 'user not found, or   whatever'})
    }
    RequestReply.create(newReply, (error, createdReply)=>{
        if(error || createdReply === null){
            return res.status(400).json({status: false, message: 'error getting data'})
        }
        // TODO Update user with the new reply  
    }
});

无论如何，使用 Mongoose 你可以使用 Promise 并摆脱那些回调、嵌套句子，我认为它更干净。