SQL vs NoSQL

---

Title: Comparative Study of SQL and NoSQL Databases

---

1. Aim

To study and compare SQL (Relational) and NoSQL (Non-relational) databases based on structure, data models, query languages, scalability, consistency, and use-cases.

---

2. Objectives

By the end of the experiment, the student will be able to:

• Understand the fundamental differences between SQL and NoSQL databases.

• Identify different types of NoSQL databases.

• Write basic queries in SQL and NoSQL.

• Analyze the ACID and BASE properties.

• Understand appropriate use-cases for both database models.

---

3. Theory

⭐ 3.1 What is SQL?

SQL (Structured Query Language) is used to manage relational databases that store data in tables.
It uses a fixed schema and supports relationships using keys.

Examples of SQL Databases:

• MySQL

• PostgreSQL

• Oracle

• Microsoft SQL Server

ACID properties ensure high reliability.

---

⭐ 3.2 What is NoSQL?

NoSQL stands for Not Only SQL. It is used for storing unstructured, semi-structured, or distributed data.

NoSQL databases are schema-less and scale horizontally.

Examples of NoSQL Databases:

• MongoDB (Document)

• Redis (Key-Value)

• Cassandra (Column Store)

• Neo4j (Graph)

Uses BASE properties and supports massive real-time data.

---

⭐ 3.3 Types of NoSQL Databases

Type	Description	Example
Document Store	JSON-like documents	MongoDB
Key-Value Store	Key → value pairs	Redis
Column-Family Store	Columns inside families	Cassandra
Graph Database	Nodes and relationships	Neo4j

---

⭐ 3.4 ACID vs BASE

ACID (SQL)	BASE (NoSQL)
Atomicity	Basically Available
Consistency	Soft State
Isolation	Eventual Consistency
Durability	—

---

4. SQL vs NoSQL – Comparison Table

Feature	SQL	NoSQL
Data Model	Tables	Documents, Key-values, Graphs
Schema	Fixed	Flexible
Query Language	SQL	No standard
Scalability	Vertical	Horizontal
Consistency	Strong	Eventual
Best for	Complex transactions	Big Data, real-time apps

---

5. Procedure

Step 1: Install MySQL (SQL Database)

Start MySQL server and open MySQL Shell.

Step 2: Install MongoDB (NoSQL Database)

Start MongoDB service and open mongo shell.

Step 3: Perform SQL Operations

Create a table, insert data, and run a query.

Step 4: Perform NoSQL Operations

Insert a document, retrieve it, and observe the structure.

Step 5: Record differences based on output.

---

6. SQL Commands (MySQL)

✔ Create a table

CREATE TABLE Students (
    id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(100),
    age INT
);

✔ Insert values

INSERT INTO Students (name, age) VALUES ('Alice', 21), ('Bob', 22);

✔ Select data

SELECT * FROM Students;

---

7. NoSQL Commands (MongoDB)

✔ Insert document

db.students.insertOne({
    name: "Alice",
    age: 21,
    subjects: ["Math", "Science"]
});

✔ Retrieve document

db.students.find();

---

8. Expected Output

SQL Output

+----+-------+------+
| id | name  | age  |
+----+-------+------+
|  1 | Alice | 21   |
|  2 | Bob   | 22   |
+----+-------+------+

NoSQL Output

{
   "_id" : ObjectId("67f4a234..."),
   "name" : "Alice",
   "age" : 21,
   "subjects" : ["Math", "Science"]
}

---

9. Applications

✔ SQL Applications

• Banking

• ERP systems

• College administration

• Inventory systems

✔ NoSQL Applications

• Social media platforms

• Big Data analytics

• IoT applications

• Real-time systems (chat apps, gaming)

10. Result

The differences between SQL and NoSQL databases were studied.
SQL was observed to follow a structured relational model, whereas NoSQL stores data in a flexible and scalable format. Both are useful for different application needs.

---