CRUD (Create, Read, Update, Delete) Operations in MongoDB

In previous articles, we have talked about installation, database, collection, and document, now we will learn to perform basic CRUD operations on Documents in MongoDB

Create Document

Creating a document refers to inserting a document in the collection, let’s see how it happens

Considering we are creating records for employees, we are going to insert below two documents in the employee collection

({"empid" : "1234","empname" : "Rajesh", "empunit": "Finance"})

({"empid" : "1235","empname" : "Mani", "empunit" : "HR"})

Read Document

Now we will see how to pull this data from collection, we have a function 

db.<collection>.find()

We can use different versions of find function 

i.e.

db.<collection>.find() : finds all documents in collection

db.<collection>.findOne() : find single document

db.<collection>.find(<condition>) : find particular document/s which satisfies condition

Updating Document

Definition of the update remains same as oracle update definition, i.e. setting up new value to attribute or parameter

let’s update the empname of an employee having id 1234 to Ramesh, so the query will be

db.employee.update ({"empid" : "1234"}, {$set: {"empname" : "Ramesh"}});

Delete Document

Syntax for deleting of document from collection is db.<collection>.remove()

let’s try deleting employee with empid 1235

We can see the entry is deleted. Similar way we can execute db.<collection>.remove() without any condition in a bracket to remove all the documents in the collection.

[Aslo read- Introduction to Mongodb]