Getting Started with MongoDB: A Beginner’s Practical Guide

2 min readFeb 7, 2025

Introduction

MongoDB is a popular NoSQL database that provides high performance, scalability, and flexibility for modern applications. In this article, I will share my learning experience with MongoDB, covering database setup, CRUD operations, indexing, aggregation, and key differences between NoSQL and relational databases.

1. Setting Up MongoDB

To start using MongoDB, you need to:
✅ Install MongoDB on your local machine or use MongoDB Atlas (cloud-based).
✅ Connect to a database using the mongo shell or a GUI tool like Compass.
✅ Create a new database using use DatabaseName.

2. CRUD Operations in MongoDB

CRUD stands for Create, Read, Update, and Delete — the fundamental operations performed on a database. Below are basic MongoDB commands:

a) Create a Collection & Insert Documents

use StudentDB  
db.createCollection("Students")

db.Students.insertMany([
  { student_id: 1, name: "Name01", age: 22, course: "Computer Science", grade: "A" },
  { student_id: 2, name: "Name02", age: 21, course: "Software Engineering", grade: "B+" }
])

b) Read Data from the Database

db.Students.find().pretty()  
db.Students.find({ course: "Computer Science" })

c) Update a Document

db.Students.updateOne({ name: "Name 02" }, { $set: { grade: "A" } })

d) Delete a Document

db.Students.deleteOne({ student_id: 2 })

3. Indexing for Faster Query Performance

Indexing improves the speed of database queries by reducing the number of scanned documents.

db.Students.createIndex({ course: 1 })

4. Aggregation in MongoDB

MongoDB’s aggregation framework is used for performing calculations, filtering, and data transformation. Example:

db.Students.aggregate([
  { $group: { _id: null, averageAge: { $avg: "$age" } } }
])

5. NoSQL vs. Relational Databases

Feature MongoDB (NoSQL) MySQL (Relational) Data Model Document-based (JSON) Table-based (Rows & Columns) Schema Flexible Schema Fixed Schema (Predefined structure) Scalability Horizontally scalable Vertically scalable Best Use Case Big data, real-time apps Traditional apps, transactions

6. Limitations & Workarounds

Limitation: MongoDB does not support JOIN operations like SQL databases.
Workaround: Use embedding or $lookup aggregation to relate documents.

Conclusion

MongoDB is a powerful NoSQL database that provides high scalability and flexibility. Throughout this assignment, I learned how to set up MongoDB, perform CRUD operations, implement indexing, and use aggregation for data analysis. Understanding these concepts helps in building efficient and scalable database solutions.

What’s Next?

🚀 If you’re interested in learning more, check out the official MongoDB documentation:
🔗 MongoDB Docs