NoSQL & MongoDB | Lecture 13

NoSQL & MongoDB 

1. What is a Database?

A database is a place where we store data permanently.

Example:

• Student details

• User login info

• Products in an e-commerce site

2. What is NoSQL?

NoSQL means Not Only SQL.

 It stores data without tables, rows, and columns.

Why NoSQL?

• Handles large data

• Very fast

• Easy to scale

• Works well with modern web apps

3. SQL vs NoSQL (Simple Table)

SQL	NoSQL
Tables	Collections
Rows	Documents
Fixed schema	Flexible schema
MySQL	MongoDB

4. Types of NoSQL Databases

1. Document-based → MongoDB 

2. Key-Value → Redis

3. Column-based → Cassandra

4. Graph → Neo4j

 We focus on MongoDB

5. What is MongoDB?

MongoDB is a NoSQL document-based database.

 It stores data in JSON-like format called BSON.

6. MongoDB Basic Terms

Term	Meaning
Database	Main container
Collection	Like a table
Document	Like a row
Field	Like a column

7. Example of MongoDB Document

{
  "name": "Aakash",
  "age": 25,
  "course": "MERN Stack"
}

 One document
 Stored inside a collection

8. MongoDB Structure

Database
 └── Collection
       └── Document

9. Install MongoDB (Basic Idea)

• Install MongoDB Community Server

• Use MongoDB Compass (GUI)

• Or use MongoDB Atlas (Cloud)

10. Create Database & Collection

use schoolDB

Create collection automatically:

db.students.insertOne({ name: "Rahul", age: 20 })

11. Insert Data

Insert One

db.students.insertOne({
  name: "Neha",
  age: 22
});

Insert Many

db.students.insertMany([
  { name: "Amit", age: 21 },
  { name: "Riya", age: 23 }
]);

12. Read Data (Find)

Find All

db.students.find()

Find with Condition

db.students.find({ age: 22 })

13. Update Data

Update One

db.students.updateOne(
  { name: "Neha" },
  { $set: { age: 23 } }
);

14. Delete Data

Delete One

db.students.deleteOne({ name: "Amit" });