How do I fetch a specific result from mongodb-CodePudding

I'm still new to reactjs and mongodb.I am trying to fetch a single record of user and display it on the page. But so far I got no output. I want the page to immediately display the result on load

This is my profile.js:

componentDidMount() {
    const user = localStorage.getItem('user')
    const userObject = {
        username: localStorage.getItem('user'),
    };
    axios.post('http://localhost:4000/users/getUser', userObject)
        .then((res) => {
            console.log("hi" res.data)
            const userinfo = res.data
            
            this.setState({
                name: userinfo.name,
                username: res.username,
                email: res.email,
                password: res.password,
                company: res.company,
                position: res.position

            })
        })
        .catch(function (error) {
            console.log(error);
        })
}

and this is my backend(user.js):

let mongoose = require('mongoose'),
express = require('express'),
router = express.Router(),
user = require('../models/user-schema');

router.post('/getUser', async (req, res) => {
console.log(req.body.username)
const User = await user.find({ name: req.body.username })

if (!User) {
    return { status: 'error', error: 'Invalid Login' }
}else {
    return res.json({
        status: 'ok',
        name: User.name,
        username: User.username,
        email: User.email,
        company:User.company,
        position: User.position,
        level: User.userLevel
    })
}

})

CodePudding user response：

user.find({ name: req.body.username }) is going to return an array. So in the code below, all those fields such User.name , User.username, User.email etc are going to be undefined since User = [{name:xxx,username:xxx }]

res.json({
        status: 'ok',
        name: User.name, // undefined
        username: User.username, // undefined
        email: User.email, // undefined
        company:User.company, // undefined
        position: User.position,// undefined
        level: User.userLevel // undefined
    })

You should use user.findOne({ name: req.body.username }) which will return a single object and then you can access the properties.

Additionally (Personal preference) , one might have multiple users with the same username. To make sure you're retrieving the correct docuemnt, rather use findById().

CodePudding user response：

Instead of this find({}) you can use findOne({}) cause find({}) going to return an array but your are expecting an object that the the problem

CodePudding user response：

Use findOne() instead of find() method, find() method returns an array of objects and findOne() method return a single particular object.

const User = await user.findOne({ name: req.body.username })

and you can pass specific filed which you want to get like

let User = await user.findOne({ name: req.body.username },{username:1, email:1, company:1, position:1, level:1});

if(!User){
  return res.status(404).json({ status: 'error', error: 'Invalid Login' });
} else {
  return res.status(404).json({status:"ok", ...User});
}