使用nodejs保存后如何从mongodb获取数据？

Question

My web application is like quiz app, the user should answer a question and the server will store the user's result in mongoDB database. what I is want is after saving the document in the database I want to get this document to send it to user in the browser note saving documents works fine . code looks like this (assuming the user's result is 10):

    const User_Result = require("../models/result_model")

router.post("/quiz/results", (req, res)=>{
       var result = new User_Result({
            _id: req.user._id,
            userResult: 10
      })
      result.save()


     //that should get data and send it but it send empty []
     User_Result.find({_id: req.user._id}).then(data=>{
            res.send(data)
        })
})

I think the problem that it looks for the data before saving it.

Answer 1

You don't need to use find as .save() will return the saved document you can just use it

Async/Await version

router.post("/quiz/results", async (req, res)=>{
       let result = new User_Result({
            _id: req.user._id,
            userResult: 10
      })
       const ReturnedResult = await result.save();
       return res.status(201).json(ReturnedResult);
})

Promise Version

router.post("/quiz/results",  (req, res) => {
    let result = new User_Result({
      _id: req.user._id,
      userResult: 10
    })
    result.save()
      .then(ReturnedResult =>return res.status(201).json(ReturnedResult))
      .catch(err => return res.status(500).json(err))

  })

Answer 2

result.save() returns a promise, you should wait for it to be resolved:

result.save().then(() => {
  User_Result.find({_id: req.user._id}).then(data=>{
    res.send(data)
  })
})

Answer 3

router.post("/quiz/results", async (req, res)=>{
       var result = new User_Result({
            _id: req.user._id,
            userResult: 10
      })
      const newResult = await result.save():
       return res.send(newResult).status(201);
})