How do I fetch a specific result from mongodb - reactjs

Question

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
})
}
})

Answer 1

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().

Answer 2

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

Answer 3

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});
}