CRUD Operations in MongoDB

Introduction

MongoDB is one of the most popular NoSQL databases used for building modern, scalable applications. Unlike traditional relational databases, MongoDB stores data in flexible JSON-like documents, making it perfect for handling real-world scenarios.

In this blog, we’ll explore CRUD operations (Create, Read, Update, Delete) with MongoDB using a simple example — a college student database.

1.create (Insert)

We start by inserting student records into our students collection.

Each student is stored as a document:

{
"student_id": "S001",
"name": "Santhosh",
"age": 20,
"department": "CSBS",
"year": 2,
"cgpa": 9
}

Insert multiple students at once:

use college;

db.students.insertMany([
{
"student_id": "S001",
"name": "Santhosh",
"age": 20,
"department": "Computer Science",
"year": 2,
"cgpa": 9
},
{
"student_id": "S002",
"name": "Priya",
"age": 21,
"department": "Computer Science",
"year": 3,
"cgpa": 8.5
},
{
"student_id": "S003",
"name": "Arjun",
"age": 19,
"department": "Electronics",
"year": 3,
"cgpa": 7.2
},
{
"student_id": "S004",
"name": "Meera",
"age": 22,
"department": "Computer Science",
"year": 1,
"cgpa": 6.8
},
{
"student_id": "S005",
"name": "Nethra",
"age": 20,
"department": "CSBS",
"year": 3,
"cgpa": 9.2
}
]);

2.read (Query)

Fetch all students:

db.students.find({});

Find all students with CGPA > 8:

db.students.find({ cgpa: { $gt: 8 } });

Find all students belonging to the CSE department:

db.students.find({ department: "Computer Science" });

3.Update

Update the CGPA of a specific student:

db.students.updateOne(
{ student_id: "S005" },
{ $set: { cgpa: 9.2};

Increase year of study for all 3rd-year students:

db.students.updateMany(
{ year: 3 },
{ $inc: { year: 1 } }
);

4.Delete

Delete one student record by ID:

db.students.deleteOne({ student_id: "S004" });

Delete all students with CGPA < 7.5:

db.students.deleteMany({ cgpa: { $lt: 7.5 } });

Conclusion

In this blog, we explored how to perform CRUD operations in MongoDB with a student database.

We:
✔ Inserted multiple student records
✔ Queried documents with filters
✔ Updated single and multiple documents
✔ Deleted records selectively