- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
How to return only value of a field in MongoDB?
In order to return only value of a field in MongoDB, you need to write a query and use forEach loop. Let us first create a collection with documents
> db.returnOnlyValueOfFieldDemo.insertOne({"ClientName":"Larry"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ea537d628fa4220163b6e") } > db.returnOnlyValueOfFieldDemo.insertOne({"ClientName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ea53bd628fa4220163b6f") } > db.returnOnlyValueOfFieldDemo.insertOne({"ClientName":"Robert"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ea541d628fa4220163b70") } > db.returnOnlyValueOfFieldDemo.insertOne({"ClientName":"Ramit"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ea549d628fa4220163b71") }
Following is the query to display all documents from a collection with the help of find() method
> db.returnOnlyValueOfFieldDemo.find().pretty();
This will produce the following output
{ "_id" : ObjectId("5c9ea537d628fa4220163b6e"), "ClientName" : "Larry" } { "_id" : ObjectId("5c9ea53bd628fa4220163b6f"), "ClientName" : "Chris" } { "_id" : ObjectId("5c9ea541d628fa4220163b70"), "ClientName" : "Robert" } { "_id" : ObjectId("5c9ea549d628fa4220163b71"), "ClientName" : "Ramit" }
Following is the query to return only value of a field in MongoDB
> var output = [] > db.returnOnlyValueOfFieldDemo.find().forEach(function(document) {output.push(document.ClientName) })
In order to get value of a field in MongoDB, you need to write variable name output at the Mongo shell (as we know the value is stored in output array). Following is the query
> output
This will produce the following output
[ "Larry", "Chris", "Robert", "Ramit" ]
Advertisements