📚 Complete SQL Basics Notes

A beginner-friendly repository containing well-structured SQL notes, examples, assignments, and explanations to help learners understand Structured Query Language (SQL) from scratch.

This repository is designed for step-by-step learning, quick revision, and interview preparation.

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🚀 About This Repository

This repository provides clear, practical, and easy-to-understand SQL content, covering everything from fundamentals to slightly advanced concepts.

It is useful for:

• 🎓 Students learning DBMS
• 💻 Beginners starting SQL
• 🧠 Quick revision before interviews/exams
• 👨‍💻 Developers needing a quick SQL reference

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📖 Topics Covered

1️⃣ Introduction to SQL

• What is SQL
• What is DBMS
• Relational Databases

2️⃣ SQL Commands

• DDL (Data Definition Language)
• DML (Data Manipulation Language)
• DCL (Data Control Language)
• TCL (Transaction Control Language)

3️⃣ Table Operations

• CREATE TABLE
• ALTER TABLE
• DROP TABLE
• TRUNCATE

4️⃣ Data Manipulation

• INSERT
• UPDATE
• DELETE

5️⃣ Data Retrieval

• SELECT
• WHERE
• ORDER BY
• GROUP BY
• HAVING

6️⃣ Joins

• INNER JOIN
• LEFT JOIN
• RIGHT JOIN
• FULL JOIN

7️⃣ Constraints

• PRIMARY KEY
• FOREIGN KEY
• UNIQUE
• NOT NULL
• CHECK
• DEFAULT

8️⃣ Advanced Concepts

• Views
• Indexes
• Sequences
• Set Operations

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💡 Example SQL Query

SELECT name, department
FROM employees
WHERE salary > 50000
ORDER BY salary DESC;

This query retrieves employees earning more than 50,000 and sorts them by salary in descending order.

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🛠 Tools to Use

You can practice SQL using:

• MySQL
• Oracle SQL
• PostgreSQL
• SQLite
• MySQL Workbench

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⚙️ Installation & Setup (MySQL Workbench)

Step 1: Install MySQL

• Download MySQL from: https://dev.mysql.com/downloads/
• Install:
  • MySQL Server
  • MySQL Workbench
• Set a root password during installation

Step 2: Open MySQL Workbench

• Launch MySQL Workbench
• Click on Local Instance MySQL
• Enter your root password

Step 3: Create a Database

CREATE DATABASE sql_practice;
USE sql_practice;

Step 4: Run SQL Files from This Repository

Method 1: Open SQL File

• File → Open SQL Script
• Select .sql file
• Click Execute (⚡)

Method 2: Copy-Paste

• Open new SQL tab
• Paste code
• Run

Method 3: Recommended Order

• Table creation
• Insert data
• Constraints / Keys
• Queries / Joins / Assignments

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📂 Repository Structure

├── 📁 Handbook & Code
│   ├── 📄 01_createusertable.sql
│   ├── 📄 02_insertdata.sql
│   ├── 📄 03_foreignkey.sql
│   ├── 📄 04_addadmin.sql
│   ├── 📄 05_log_table.sql
│   └── 📕 MySQL Handbook.pdf
├── 📁 assignments
│   ├── 📝 assignments.md
│   ├── 📕 sql_assignment.pdf
│   └── 📕 sql_views_assignment.pdf
├── 📄 Joins.sql
├── 📄 Keys.sql
├── 📄 SubQueries.sql
├── 📄 Views.sql
├── 📄 aggregateFunctions.sql
├── 📄 constraints.sql
├── 📄 companyDatabase.sql
├── 📄 exercise.sql
├── 📄 joinsExercise.sql
├── 📄 operators.sql
├── 📄 project.sql
├── 📄 questions.sql
├── 📝 readme.md
└── 📄 table_related_queries.sql

Structure may change as more files are added.

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🎯 Who Should Use This

• Computer Science Students
• Beginners in Databases
• Coding Interview Aspirants
• Backend Developers
• Data Analysts

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🤝 Contributions

Contributions are welcome!

1. Fork the repository
2. Create a new branch
3. Make improvements
4. Submit a Pull Request

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⭐ Support

If you find this repository helpful:

• ⭐ Star the repository
• 🔗 Share it with others

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👨‍💻 Author

Rishiraj Pathak
Computer Engineering Student
Passionate about Programming, Databases, and Software Development

GitHub:
https://github.com/Rishiraj-Pathak-27