How can I connect MongoDB with Node.js? - node.js

Question

I am trying to connect MongoDB with my signup.js, but it's not connecting. I am unable to find the problem. How can I solve this?
Code of signup.js:
const express = require('express')
const app = express()
require("./db/mydb");
app.get('/', (req, res) => {
res.send('Hello World!')
})
app.listen(4000, () => {
console.log(`App listening on port 4000`)
})
Code of mydb.js:
const mongoose = require("mongoose");
mongoose.connect("mongodb://localhost:27017/mydata",{
useNewUrlParser:true,
useUnifiedTopology:true,
useCreateIndex:true
}).then(()=>{
console.log("connection successful")
}).catch((e)=>{
console.log("Not connected")
})
Error:
App listening on port 4000
Not connected
If the last log statement is replaced with console.log(e), the output is:
MongoParseError: option usecreateindex is not supported

Answer 1

Here you have a simple example of how to connect MongoDB to Node.js using Express.js and Mongoose on localhost obviously:
File server.js
const express = require("express");
const mongoose = require("mongoose");
const app = express();
const port = 3000;
app.get("/", (req, res) => {
res.send("Express and Mongoose connection!");
});
// Connect to db
mongoose
.connect("mongodb://localhost:27017/test")
.then(() => {
// Listen for requests
app.listen(port, () => {
console.log(
`Connected to DB & Server is listening at http://127.0.0.1:${port}`
);
});
})
.catch((error) => {
console.log(error);
});
And as we can read in the Mongoose documentation → no more deprecation warning options
useNewUrlParser, useUnifiedTopology, useFindAndModify, and
useCreateIndex are no longer supported options. Mongoose 6 always
behaves as if useNewUrlParser, useUnifiedTopology, and useCreateIndex
are true, and useFindAndModify is false. Please remove these options
from your code.
It was tested with: "express": "^4.18.1", "mongoose": "^6.6.5"