How to use async and await with Express and MongoDB - express

Question

const express = require('express');
const bodyParser = require('body-parser');
const cors = require('cors');
const mongodb = require('mongodb');
const app = express();
app.use(cors())
app.use(bodyParser.json());
const MongoClient = mongodb.MongoClient;
const url = "mongodb://localhost:27017/recart";
app.post("/register" , (req, res) => {
const { displayName, email, password } = req.body;
if (!email || !displayName || !password) {
return {code: 400, msg: "incorrect form submission"}
}
let insertedid = null
MongoClient.connect(url, (err, db) => {
if (err) throw err;
var dbo = db.db("recart");
var myobj = { displayName: displayName, email: email, password: password };
dbo.collection("customers").insertOne(myobj)
.then(res => {
insertedid = res.insertedId
})
});
res.json({id: insertedid})
})
app.listen(process.env.PORT || 3000, ()=> {
console.log(`App is running on port 3000`);
})
Here, I am storing data inside db and sending the last inserted id
to the frontend.
However, id is returning null.
How can I use async and await to solve this issue?

Answer 1

You can modify your post function using async await like this:
app.post("/register", async (req, res) => {
const { displayName, email, password } = req.body;
if (!email || !displayName || !password) {
return {code: 400, msg: "incorrect form submission"}
}
let insertedid = null ;
MongoClient.connect(url,{ useNewUrlParser: true }, async (err, db) => {
if (err) throw err;
var dbo = db.db("recart");
var myobj = { displayName: displayName, email: email, password: password };
var result = await dbo.collection("customers").insertOne(myobj);
insertedid = result.insertedId;
res.json({ id: insertedid})
});
})