MEAN stack application - getting details of a single user, querying by username - node.js

Question

I have built an API to GET and POST values into a database(MongoDB) using NodeJS and Express.
I am able to get the total list of users stored on my database (localhost:3000/user)
But I want to get a single users details by either entering the userID or userName(localhost:3000/user/:username)(localhost:3000/user/:userID)
I am able to get a single users details through ObjectID(localhost:3000/user/:id)
App.js
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
//var routes = require('./routes/index');
//var users = require('./routes/users');
//Router for developers
var developer = require('./routes/developer');
//Router for TvShows
var tvshow = require('./routes/tvshow');
//Router for TvShows
var user = require('./routes/user');
//Router for TvShowRating
var tvshowrating = require('./routes/tvshowrating');
//Router for TvShowEpisodes
var tvshowepisodes = require('./routes/tvshowepisodes');
//Router for TvShowNewsFeed
var tvshownewsfeed = require('./routes/tvshownewsfeed');
//Router for TvShowSeason
var tvshowseason = require('./routes/tvshowseason');
//Router for TvShowRatingUser
var tvshowratinguser = require('./routes/tvshowratinguser');
// load mongoose package
var mongoose = require('mongoose');
// Use native Node promises
mongoose.Promise = global.Promise;
// connect to MongoDB
//mongoose.connect('<string>')
//mongoose.connect('mongodb://localhost/televisionary-api')
.then(() => console.log('connection succesful'))
.catch((err) => console.error(err));
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
//Registering routers
app.use('/developer', developer);
app.use('/tvshow', tvshow);
app.use('/user', user);
app.use('/tvshowrating', tvshowrating)
app.use('/tvshowepisodes', tvshowepisodes)
app.use('/tvshownewsfeed', tvshownewsfeed)
app.use('/tvshowseason', tvshowseason)
app.use('/tvshowratinguser', tvshowratinguser)
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
. routes/User.js
var express = require('express');
var router = express.Router();
var User = require('../models/User.js');
/* GET /user listing. */
router.get('/', function(req, res, next) {
User.find(function (err, user) {
if (err) return next(err);
res.json(user);
});
});
/* POST /user */
router.post('/', function(req, res, next) {
User.create(req.body, function (err, post) {
if (err) return next(err);
res.json(post);
});
});
/* GET /user/id */
router.get('/:id', function(req, res, next) {
User.findById(req.params.id, function (err, post) {
if (err) return next(err);
res.json(post);
});
});
/* PUT /user/:id */
router.put('/:id', function(req, res, next) {
User.findByIdAndUpdate(req.params.id, req.body, function (err, post) {
if (err) return next(err);
res.json(post);
});
});
/* DELETE /user/:id */
router.delete('/:id', function(req, res, next) {
User.findByIdAndRemove(req.params.id, req.body, function (err, post) {
if (err) return next(err);
res.json(post);
});
});
module.exports = router;
. models/User.js
var mongoose = require('mongoose');
var userSchema = new mongoose.Schema({
userId:Number,
userName: String,
userEmail: String,
userPassword: String,
userCreatedDateTime: Date,
userWatchList: [
{
watchListItemId:Number,
tvShowId: Number,
tvShowSeasonId: Number,
tvShowEpisodeId: Number,
tvShowAddedDateTime: Date
}
],
userFavouriteList: [
{
favouriteId:Number,
tvShowId: Number,
tvShowFavouritedDateTime: Date
}
],
userRatings: [
{
tvShowUserRatingId:Number,
tvShowId: Number,
tvShowSeasonId: Number,
tvShowEpisodeId: Number,
tvShowRatedDateTime: Date,
tvShowRating: Number,
tvShowUserTags:[String]
}
]
});
module.exports = mongoose.model('User', userSchema);

Answer 1

If you want to get user details by entering username or userid in one service then modify your service with this:
router.get('/:keyword', function(req, res, next){
User.findOne({$or:[{userName: req.params.keyword}{userId:req.params.keyword}]},
function (err, post) {
if (err) return next(err);
res.json(post);
});
});

Answer 2

You can use findOne method to get a specific user from a database.
router.get('/user/:username', function(req, res, next) {
User.findOne({userName: req.params.username}, function(err, user) {
if(err)
console.log(err);
else
//do something with user
})
});
Same for fetching user using userId.