Mongoose.connect is not working

my code:

const mongoose=require('mongoose');

mongoose.connect('mongodb://localhost:27017/shortner',{
    useCreateIndex:true,
    useNewUrlParser:true,
    useUnifiedTopology:true
}).then(()=>{
    console.log("connection is successfull");
}).catch((e)=>{
    console.log("no connection ");
});

I tried connecting mongodb with mongoose but its not working. I am getting “no connection” in my console.

I wrote this in other file and required it in my index.js file.Here is code of my index.js file:

const express= require('express');
require("../main/db/conn");
const app=express();
const port= process.env.PORT || 8000;
app.set('view engine','ejs');
app.get('/',(req,res)=>{
    res.render('index',{name:'sonai'})
});

app.listen(port,()=>{
    console.log("server is starting")
});

Please if anyone can help me with this.

Hi,
Are you running your database server? If so, how?

It happens on the local server if you do not install Mongosh or not upgrade it.