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 calculate average of a particular field in MongoDB?
To calculate average of a particular field, use aggregate() along with $avg. Let us create a collection with documents −
> db.demo214.insertOne({"Marks":56,"Name":"David"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e3e319403d395bdc2134705")
}
> db.demo214.insertOne({"Marks":86,"Name":"Bob"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e3e319c03d395bdc2134706")
}
> db.demo214.insertOne({"Marks":78,"Name":"Carol"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e3e31a403d395bdc2134707")
}Display all documents from a collection with the help of find() method −
> db.demo214.find();
This will produce the following output −
{ "_id" : ObjectId("5e3e319403d395bdc2134705"), "Marks" : 56, "Name" : "David" }
{ "_id" : ObjectId("5e3e319c03d395bdc2134706"), "Marks" : 86, "Name" : "Bob" }
{ "_id" : ObjectId("5e3e31a403d395bdc2134707"), "Marks" : 78, "Name" : "Carol" }Following is the query to calculate average of a particular field in MongoDB −
> db.demo214.aggregate(
... [
... {
... $group:
... {
...
... "_id":"_id",
... AverageValue: { $avg: "$Marks" }
... }
... }
... ]
...)This will produce the following output
{ "_id" : "_id", "AverageValue" : 73.33333333333333 }
Updated on: 30-Mar-2020
3K+ Views
Advertisements