Im trying to get a response from my '/users/:uid' endpoint, where it should return data of the specific user if the user is in the database, but it does not work. I get this error: The error

I have a userController file, where i have implemented the function for finding the user based on id in the URL and the userController file is seen in the below:

import { Request, Response } from "express";
import mongoose from "mongoose";
import { schema } from "../models/User";
import { User } from "../models/User";
import {ROUNDS, SALT_LENGTH, KEY_LENGTH, ITERATIONS, DIGEST, pbkdf2, randomBytes} from 
"../../authCrypto"
import { join } from 'path'

const X5U = 'http://localhost:3000/auth-rsa256.key.pub';
const PATH_PRIVATE_KEY = join(__dirname, '..', '..', 'auth-rsa.key');

const usersConnection = mongoose.createConnection('mongodb://localhost:27017/users')
const UserModel = usersConnection.model('User', schema)

const listUsers = async (req: Request, res: Response) => {
    let result = await UserModel.find({}, ).lean().exec();
    res.json(result);
  };

const getUser = async (req: Request, res: Response) => {
    const {uid} = req.params
    let result = await UserModel.find({_id: uid}).lean().exec();
    if(!result){
      res.json({
        "message": "The user is not found"
      });
    }
    res.json(result);
}


module.exports = {
    listUsers,
    getUser
};

And this is my User model:

import { Schema } from 'mongoose';

export enum Role {
    manager = "Manager",
    clerk = "Clerk",
    guest = "Guest"
}

export interface User{
    firstName: string;
    middleName: string;
    lastName: string;
    email: string;
    role: Role;
    password: string;
    salt: string;
}

export const schema = new Schema<User>({
    firstName: { type: String, required: true },
    middleName: { type: String, required: true },
    lastName: { type: String, required: true },
    email: { type: String, required: true },
    role: { type: String, required: true },
    password: { type: String, required: true },
    salt: { type: String, required: true},
  });

And this is my userRouter:

import { Router } from "express";
const userController = require('../controller/userController')

const userRouter = Router();

userRouter.get('/users', userController.listUsers);

userRouter.get('/users/:uid', userController.getUser);

module.exports = userRouter;

And this is my index file, which is the startfile of the application:

const express = require("express");
const app = express();
const port = 3000;

app.use('/', require("./router/userRouter"));
app.use('/rooms', require('./router/roomRouter'));
app.use('/reservations', require('./router/reservationRouter'));

app.listen(port, () => {
  return console.log(`Express is listening at http://localhost:${port}`);
});

CodePudding user response：

The issue:

Based on the error, it looks like the route is passing in "1" as the :uid parameter, but the Mongoose .find() method is trying to coerce it into Mongo's ObjectId type.

By default, the _id key in MongoDB is an ObjectId. ObjectIds are typically a 24 hexadecimal character string (or anything that's 12 bytes), so "1" can't be turned into an ObjectId.

To solve:

• You could set the _id column to be of type string or number instead of ObjectId manually.
• You could keep the _ids as ObjectId type and modify your code to make sure you're passing in valid ids while searching (--adding pre-validation or an error handling wrapper might be good in that case so that the user gets 400s/404s instead of 500s if something wrong is passed in as a param).

Helpful Resources

Here's a specific rundown on the difference between how the code might look for an _id that's a string/number vs. an ObjectId type-- the part about ObjectIds is at the bottom: https://masteringjs.io/tutorials/mongoose/find-by-id

Here's some more information general info on MongoDB ObjectIds: https://masteringjs.io/tutorials/mongoose/objectid

Here's some info about the difference between _id and id in case that helps with the way you end up wanting to write your queries: What is the difference between id and _id in mongoose?