node.js - my post request using nodejs express to mongodb database doesn't work strangely? -

i trying post data sever save mongodb. notice request working right couldnt post data mongodb database.

the main code:

// tools used in web development var express = require('express'); var app = express(); var bodyparser = require('body-parser'); var mongoose = require('mongoose');  app.use(bodyparser.json());   genre = require('./models/genre.js'); book = require('./models/book.js');    let conn = mongoose.connection; conn.openuri('mongodb://localhost/bookstore');  conn.on('error', err => console.error('mongodb connection error',  err)); conn.on('connected', () => console.info(`connected mongodb`)); conn.on('disconnected', () => console.info('disconnected  mongodb'));   // routing specific pages: app.get('/', function(req, res){ res.send('hello world'); });  app.get('/api/genres', function(req , res){ genre.getgenres(function(err, genres){     if(err){         throw err;     }     res.json(genres); }) });  app.post('/api/genres', function(req , res){ var genre = req.body; genre.addgenre(genre, function(err, genre){     if(err){         throw err;     }     res.json(genre); }) });  app.get('/api/books', function(req , res){ book.getbooks(function(err, books){     if(err){         throw err;     }     res.json(books); }) });  app.get('/api/books/:_id', function(req , res){ book.getbookbyid(req.params._id, function(err, book){     if(err){         throw err;     }     res.json(book); }) });  //specify listening port app.listen(3666); //display url on termianl console.log('server running on http://localhost:3666'); 

genres

var mongoose = require('mongoose');   var genreschema = mongoose.schema({ name:{     type: string,     requires: true }, create_date:{     type: date,     default: date.now } });  var genre = module.exports = mongoose.model('genre', genreschema);  module.exports.getgenres = function(callback, limit){ genre.find(callback).limit(limit);  }  //add genre module.exports.addgenre = function(genre, callback){ genre.create(callback);  } 

i post using postman app , once press post receive nothing , nothing added database

postman procedure

postman procedure

and database before , after post procedure remain same

enter image description here

try instead:

module.exports.addgenre = function(genre, callback){    genre.create(genre, callback); // genre object added, { name: "name" } example }