node.js mongoose find() not value - node.js

Question

route/signup.js
var express = require('express');
var router = express.Router();
const User = require('../model/user');
var mongoose = require('mongoose');
function userFind(value){
return User.find({user_id:value}).exec();
};
router.get('/',function (req,res) {
res.render('login/signup');
});
router.post('/',async function (req,res,next){
try{
let userid =req.body.id;
console.log(userid); //abcdefg
const user = await userFind(userid);
console.log(user); // []
}catch(err){
next(err);
}
})
module.exports = router;
model/user.js
const mongoose = require('mongoose')
var Schema = mongoose.Schema;
const userSchema = new Schema(
{ user_id : {type:String,required:true, unique:true},
user_password : {type:String, required:true, select:false},
user_name: {type:String, required:true},
user_email : {type:String,required:true,unique : true},
user_birth : {type:String,require:true},
},{versionKey:false},
{collection: 'user'}
);
module.exports = mongoose.model('user',userSchema);
data inside mongodb.
{
"_id": {
"$oid": "60413c7c48e5e61187cc4eeb"
},
"user_id": "abcdefg",
"user_password": "test111",
"user_name": "세글자",
"user_email": "test#naver.com",
"user_birth": "884455"
}
app.js
var express = require('express');
var mongoose = require('mongoose');
const bodyParser = require('body-parser');
var db = mongoose.connection;
db.on('error', console.error);
db.once('open', function(){
// CONNECTED TO MONGODB SERVER
console.log("Connected to mongod server");
});
mongoose.connect("mongodb+srv://testing1:7894#cluster0.9hxjc.mongodb.net/data?
retryWrites=true&w=majority", { useNewUrlParser: true, useUnifiedTopology:
true });
var app = express();
var test = require('./route/index');
var test2 = require('./route/signup');
app.use(bodyParser.urlencoded({extended:false}));
app.use(bodyParser.json());
app.set('views',__dirname+'/views'); // ==
app.set('views',path.join(__dirname, 'views'));
app.set('view engine','ejs');
app.engine('html',require('ejs').renderFile);
app.use('/',test);
app.use('/signup.ejs',test2);
app.listen(3000,function(){
console.log('hello world');
});
Hello, I am studying using mogoose and node.js. I ran mongoose find() but the result was only []. I don't know why this is so, I would appreciate it if you let me know. And if it is findOne(), how should I write it? I tried writing it once, but it turned out to be null.

Answer 1

Through chatting in comments we found the issue. The model is called user:
module.exports = mongoose.model('user',userSchema);
Which mongoose will connect to a collection named users (plural) in MongoDB. That collection was indeed empty. There was only content in a collection named user.