Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
AmitDiwan has Published 10740 Articles
AmitDiwan
379 Views
To compare fields from an array, use $gt and $lt. Let us create a collection with documents −> db.demo147.insertOne({"Details":[{"Score":45}, {"Score":46}]}); { "acknowledged" : true, "insertedId" : ObjectId("5e32fa21fdf09dd6d08539be") } > db.demo147.insertOne({"Details":[{"Score":65}, {"Score":86}]}); { "acknowledged" : true, "insertedId" : ObjectId("5e32fa40fdf09dd6d08539bf") }Display all documents from a collection with the ... Read More
AmitDiwan
219 Views
To remove an array element, simply use $pull along with update(). Let us create a collection with documents −> db.demo146.insertOne({"ListOfEmployeeNames":["Chris", "David", "Bob", "Mike"]}); { "acknowledged" : true, "insertedId" : ObjectId("5e32f54ffdf09dd6d08539bd") }Display all documents from a collection with the help of find() method −> db.demo146.find();This will produce the following ... Read More
AmitDiwan
240 Views
For writing an equality, you can simply use find() along with match value. Let us create a collection with documents −> db.demo145.insertOne({"ListOfNames":["Chris", "David", "Mike"]}); { "acknowledged" : true, "insertedId" : ObjectId("5e32f37bfdf09dd6d08539bb") } > db.demo145.insertOne({"ListOfNames":["Bob", "John"]}); { "acknowledged" : true, "insertedId" : ObjectId("5e32f384fdf09dd6d08539bc") }Display all documents from ... Read More
AmitDiwan
307 Views
Let us first create a collection with documents −>db.demo144.insertOne({"EmployeeDetails":[{"EmployeeName":"Chris", "EmployeeEmail":"Chris12@gmail.com"}, {"EmployeeName":"Bob", "EmployeeEmail":"bo22@gmail.com"}]}); { "acknowledged" : true, "insertedId" : ObjectId("5e32f1d8fdf09dd6d08539b9") } >db.demo144.insertOne({"EmployeeDetails":[{"EmployeeName":"David", "EmployeeEmail":"david@gmail.com"}, {"EmployeeName":"Carol", "EmployeeEmail":"Carol@gmail.com"}]}); { "acknowledged" : true, "insertedId" : ObjectId("5e32f1f5fdf09dd6d08539ba") }Display all documents from a collection with the help of find() method −> db.demo144.find();This will ... Read More
AmitDiwan
897 Views
For this, simply use update() to update. Let us create a collection with documents −> db.dem0143.insertOne({"StudentId":1, "Details":{"Name":"Chris"}}); { "acknowledged" : true, "insertedId" : ObjectId("5e32eb9efdf09dd6d08539b7") } > db.dem0143.insertOne({"StudentId":2, "Details":{"Name":"David"}}); { "acknowledged" : true, "insertedId" : ObjectId("5e32eba5fdf09dd6d08539b8") }Display all documents from a collection with the help of find() ... Read More
AmitDiwan
938 Views
For this, you can use aggregate(). Let us create a collection with documents −> db.demo142.insertOne({"Value":50}); { "acknowledged" : true, "insertedId" : ObjectId("5e32e9c6fdf09dd6d08539b2") } > db.demo142.insertOne({"Value":45}); { "acknowledged" : true, "insertedId" : ObjectId("5e32e9cafdf09dd6d08539b3") } > db.demo142.insertOne({"Value":60}); { "acknowledged" : true, "insertedId" : ObjectId("5e32e9cdfdf09dd6d08539b4") } > ... Read More
AmitDiwan
6K+ Views
To find last object in collection, at first sort() to sort the values. Use limit() to get number of values i.e. if you want only the last object, then use limit(1).Let us first create a collection with documents −> db.demo141.insertOne({"Name":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5e31c347fdf09dd6d08539ae") } ... Read More
AmitDiwan
326 Views
For such kind of fetching, use only $nin and $in. Let us create a collection with documents −> db.demo140.insertOne({"Id":101, "Subjects":["MongoDB", "MySQL"]}); { "acknowledged" : true, "insertedId" : ObjectId("5e31c149fdf09dd6d08539a9") } > db.demo140.insertOne({"Id":102, "Subjects":["MongoDB", "Java"]}); { "acknowledged" : true, "insertedId" : ObjectId("5e31c14cfdf09dd6d08539aa") } > db.demo140.insertOne({"Id":103, "Subjects":["MongoDB", "PL/SQL"]}); { ... Read More
AmitDiwan
1K+ Views
For this, use aggregate(). Let us create a collection with documents −>db.demo138.insertOne({"Id":101, "PlayerDetails":[{"PlayerName":"Chris", "PlayerScore":400}, {"PlayerName":"David", "PlayerScore":1000}]}); { "acknowledged" : true, "insertedId" : ObjectId("5e31bb9ffdf09dd6d08539a1") } >db.demo138.insertOne({"Id":102, "PlayerDetails":[{"PlayerName":"Bob", "PlayerScore":500}, {"PlayerName":"Carol", "PlayerScore":600}]}); { "acknowledged" : true, "insertedId" : ObjectId("5e31bbcefdf09dd6d08539a2") }Display all documents from a collection with the help of ... Read More
AmitDiwan
2K+ Views
For this, use aggregate() along with $filter. Let us create a collection with documents −> db.demo137.insertOne( ... { ... Name1:"Chris", ... Name2:"David", ... Detail1:[ ... {_id:"John", Name3:"Chris"}, ... {_id:"Chris", Name3:"Chris"}, ... ... Read More