CRUD Operations in SQL vs NoSQL Explained with Simple Examples

🔷 Part 6: CRUD Operations in SQL vs NoSQL – A Beginner's Guide

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This post will:

• ✅ Compare how to Create, Read, Update, and Delete data in both systems

• ✅ Use simple, realistic examples

• ✅ Help beginners understand key syntax differences

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📍 Introduction

In any application or system that works with data, you need to perform four basic operations:

• Create new data

• Read existing data

• Update current data

• Delete data you no longer need

These are called CRUD operations — and whether you're using SQL or NoSQL, they form the core of working with databases.

Let’s explore these operations in both SQL (like MySQL/PostgreSQL) and NoSQL (like MongoDB) with clear, side-by-side examples.

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🔸 Assumed Data Structure

We’ll use a simple students table/collection with:

• StudentID

• Name

• Class

• Marks (embedded in NoSQL)

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📌 1. CREATE – Inserting Data

✅ SQL (MySQL/PostgreSQL)

INSERT INTO Students (StudentID, Name, Class)
VALUES (1, 'Aisha', '10A');

✅ NoSQL (MongoDB)

db.students.insertOne({
  student_id: 1,
  name: "Aisha",
  class: "10A",
  marks: [
    { subject: "Math", score: 85 }
  ]
});

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📌 2. READ – Retrieving Data

✅ SQL

SELECT * FROM Students WHERE StudentID = 1;

✅ NoSQL

db.students.findOne({ student_id: 1 });

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📌 3. UPDATE – Changing Data

✅ SQL

UPDATE Students
SET Class = '10B'
WHERE StudentID = 1;

✅ NoSQL

db.students.updateOne(
  { student_id: 1 },
  { $set: { class: "10B" } }
);

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📌 4. DELETE – Removing Data

✅ SQL

DELETE FROM Students
WHERE StudentID = 1;

✅ NoSQL

db.students.deleteOne({ student_id: 1 });

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📊 Quick Comparison Table

Operation	SQL Syntax	MongoDB (NoSQL) Syntax
Create	INSERT INTO ... VALUES (...)	insertOne({ ... })
Read	SELECT * FROM ... WHERE ...	findOne({ ... })
Update	UPDATE ... SET ... WHERE ...	updateOne({ ... }, { $set: { ... } })
Delete	DELETE FROM ... WHERE ...	deleteOne({ ... })

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🧠 Summary

SQL	NoSQL (MongoDB)
Structured (tables/rows)	Flexible (documents/JSON)
Uses SQL language	Uses JavaScript-like syntax
Schema-based	Schema-less
Great for complex queries	Great for rapid, dynamic data

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✅ What’s Next?

In Part 7, we’ll explore Normalization vs Denormalization — how SQL and NoSQL structure data differently for performance and flexibility.

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