- Trending Categories
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
Found 1659 Articles for Big Data Analytics
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
959 Views
To aggregate nested array in MongoDB, use aggregate(). Let us create a collection with documents −> db.demo441.insertOne( ... { ... ... "Name" : "David", ... "Age" : 21, ... ... "details" : [ ... { ... "id" : 1, ... "CountryName" : "US", ... "details1" : [ ... { ... "SubjectName" : ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
213 Views
To count items in array, use length. Let us create a collection with documents −> db.demo440.insertOne( ... { ... "Name":"Chris", ... "ListOfFriends":["John", "Sam", "Mike"] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e78c63cbbc41e36cc3caeb5") } > > db.demo440.insertOne( ... { ... "Name":"David", ... "ListOfFriends":["Mike", "Bob", "Carol"] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e78c63cbbc41e36cc3caeb6") }Display all documents from a collection with the help of find() method −> db.demo440.find();This will produce the following output −{ "_id" : ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
158 Views
To project field in MongoDB, use $project. Let us create a collection with documents −> db.demo439.insertOne( ... { ... "Name" : "Chris", ... "MarksInformation" : { ... "Marks1" : 67, ... "Marks2" :45, ... "Marks3" : 78 ... } ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e77833abbc41e36cc3caeab") } > db.demo439.insertOne( ... { ... "Name" : "David", ... "MarksInformation" : { ... ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
262 Views
To remove duplicate record, use aggregate(). Let us create a collection with documents −> db.demo438.insertOne({"FirstName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5e775c37bbc41e36cc3caea1") } > db.demo438.insertOne({"FirstName":"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5e775c3dbbc41e36cc3caea2") } > db.demo438.insertOne({"FirstName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5e775c40bbc41e36cc3caea3") } > db.demo438.insertOne({"FirstName":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5e775c44bbc41e36cc3caea4") } > db.demo438.insertOne({"FirstName":"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5e775c47bbc41e36cc3caea5") }Display all documents from a collection with the help of find() method −> db.demo438.find();This will produce the following output −{ "_id" : ObjectId("5e775c37bbc41e36cc3caea1"), "FirstName" : "Chris" } { ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
188 Views
For validation in MongoDB, use validator. Following is the query to create validation on collection in MongoDB −> db.createCollection( "demo437" , { ... validator: { $jsonSchema: { ... bsonType: "object", ... required: [ "FirstName", "LastName"], ... properties: { ... FirstName: { ... bsonType: "string", ... description: "This is required" }, ... LastName: { ... bsonType: "string", ... ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
1K+ Views
To merge multiple documents in MongoDB, use aggregate(). Let us create a collection with documents −> db.demo436.insertOne( ... { ... "_id" : "101", ... "Name": "Chris", ... "details" : [ ... { ... "CountryName" : "US", ... "Age" : 21 ... } ... ], ... "Price" : 50 ... } ... ); { "acknowledged" : true, "insertedId" : "101" } > db.demo436.insertOne( ... ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
259 Views
To append to array in MongoDB, use $concatArrays. Let us create a collection with documents −> db.demo435.insertOne({"FirstName":["Chris"], "LastName":["Brown"]} ); { "acknowledged" : true, "insertedId" : ObjectId("5e7719b1bbc41e36cc3cae97") } > db.demo435.insertOne({"FirstName":["David"], "LastName":["Miller"]} ); { "acknowledged" : true, "insertedId" : ObjectId("5e7719bdbbc41e36cc3cae98") } > db.demo435.insertOne({"FirstName":["John"], "LastName":["Doe"]} ); { "acknowledged" : true, "insertedId" : ObjectId("5e7719c6bbc41e36cc3cae99") }Display all documents from a collection with the help of find() method −> db.demo435.find().pretty();This will produce the following output −{ "_id" : ObjectId("5e7719b1bbc41e36cc3cae97"), "FirstName" : [ "Chris" ], "LastName" : [ ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
197 Views
To sum, use aggregate() along with $sum. Let us create a collection with documents −> db.demo434.insertOne({"Name":"Chris", "Score":45}); { "acknowledged" : true, "insertedId" : ObjectId("5e771603bbc41e36cc3cae93") } > db.demo434.insertOne({"Name":"David", "Score":55}); { "acknowledged" : true, "insertedId" : ObjectId("5e77161abbc41e36cc3cae94") } > db.demo434.insertOne({"Name":"Chris", "Score":55}); { "acknowledged" : true, "insertedId" : ObjectId("5e771624bbc41e36cc3cae95") }Display all documents from a collection with the help of find() method −> db.demo434.find();This will produce the following output −{ "_id" : ObjectId("5e771603bbc41e36cc3cae93"), "Name" : "Chris", "Score" : 45 } { "_id" : ObjectId("5e77161abbc41e36cc3cae94"), "Name" : "David", "Score" : 55 } { "_id" : ObjectId("5e771624bbc41e36cc3cae95"), "Name" : "Chris", ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
2K+ Views
To filter a query on specific date format, use $dateToString. Let us create a collection with documents −> db.demo433.insertOne({"DueDate":new Date("2019-11-23")}); { "acknowledged" : true, "insertedId" : ObjectId("5e771278bbc41e36cc3cae91") } > db.demo433.insertOne({"DueDate":new Date("2020-01-03")}); { "acknowledged" : true, "insertedId" : ObjectId("5e771290bbc41e36cc3cae92") }Display all documents from a collection with the help of find() method −> db.demo433.find();This will produce the following output −{ "_id" : ObjectId("5e771278bbc41e36cc3cae91"), "DueDate" : ISODate("2019-11-23T00:00:00Z") } { "_id" : ObjectId("5e771290bbc41e36cc3cae92"), "DueDate" : ISODate("2020-01-03T00:00:00Z") }Following is the query to filter a query on specific date format in MongoDB −> db.demo433.aggregate([ ... { $addFields: {stringDate: { $dateToString: { format: ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
87 Views
For this, you can use aggregate(). We have considered test records as “Value1”, “Value2”, etc. Let us create a collection with documents −> db.demo432.insertOne( ... { ... "_id" : 101, ... "Name" : "David", ... "Value1" : 67, ... "Value2" : 87, ... "Value3" : 78 ... } ... ) { "acknowledged" : true, "insertedId" : 101 } > db.demo432.insertOne( ... { ... "_id" : 102, ... "Name" : "Sam", ... "Value1" : ... Read More