How to get multiple documents with limited fields- MongoDB

Getting multiple data from mongodb with limited fields is an easy process.

Let's see an example. Here is a list of documents in Users collection. 

  {
  "_id":ObjectId("5ebadc45a99bde77b2efc16a"),
  "username":"tradecoder",
  "userType":"admin",
  "email":"tradecoderbd@gmail.com",
  "firstName":"trade",
  "lastName":"coder",
  "password":"12345678",
  "createdAt":"2020-12-13T16:39:30.385Z",
  "updatedAt":"2020-12-13T16:39:30.385Z"
  },
  {
  "_id":ObjectId("5ebadc45a99bde77b2efc16b"),
  "username":"user2",
  "userType":"editor",
  "email":"user2@example.com",
  "firstName":"first name",
  "lastName":"last name",
  "password":"12345678",
  "createdAt":"2020-12-14T16:39:30.385Z",
  "updatedAt":"2020-12-14T16:39:30.385Z"
  },
  {
  "_id":ObjectId("5ebadc45a99bde77b2efc16c"),
  "username":"user3",
  "userType":"author",
  "email":"user3@example.com",
  "firstName":"first name",
  "lastName":"last name",
  "password":"12345678",
  "createdAt":"2020-12-15T16:39:30.385Z",
  "updatedAt":"2020-12-15T16:39:30.385Z"
  }

Now, if we want all the documents from the collection but with limited fields, like,
if we need only the username and userType from all the documents, we can do it by this way

Users.find({}, {username:true, userType:true, _id:0})

This will return an array containing the following data

[
  {  
  "username":"tradecoder",
  "userType":"admin" 
  },
  {
  "username":"user2",
  "userType":"editor"
  },
  {
  "username":"user3",
  "userType":"author"  
  } 

]


Node, express, mongodb working code

Here router is express router
const router = require('express').Router();
and Users is our database collection 

router.route('/api/get-users/')
.get((req, res)=>{
Users.find({}, {username:true, userType:true, _id:0})
.then(data=>res.send(data))
.catch(err=>res.send(err))
})

Read more on TradeCoder : MongoDB Section

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