猫鼬的findOne函数返回null / undefined

Question

I always get null / undefined when fetching data from the database in my /authenticate route. Connection is successful and the user exists in the database (checked with Robo 3T). Here is an excerpt of the code:

var express = require("express");
var app = express();
var router = express.Router();
var mongoose = require("mongoose");
var user = require("../models/user");
var bodyParser = require("body-parser");
app.use(bodyParser.json());

router.post('/authenticate', function(req, res) {    
   user.findOne({ name: req.body.name }).then(function(foundUser) {
       if (!foundUser) { return res.status(404).send("No user matching name"); }
       return res.status(200).json(foundUser);
   });
});

Here is the request I'm executing from Postman:

Answer 1

Edited answer:

For express to parse form data in addition to json you need to add a second body parser to your application:

var app = require('express');
var bodyParser = require('body-parser');

// Enable express to parse body data from raw application/json data
app.use(bodyParser.json());

// Enables express to parse body data from x-www-form-encoded data
app.use(bodyParser.urlencoded({ extended: false }));

Answer 2

req.body.name it may be null, so findOne() may return null

var query = user.findOne({name: req.params.name});

its depends on your route calling method try to use req.params.name

Answer 3

try making a test in mongo shell on your server. Print db.user.find(); and check your user