🚀 SQL Zero to Hero Roadmap

Welcome to the SQL Zero to Hero Roadmap! This repository is designed to take you from the absolute basics of databases to advanced queries and real-world database design. It contains a structured, phase-wise learning path complete with theoretical notes and practical SQL scripts.

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📂 Repository Structure

The learning materials are divided into 18 systematic folders, culminating in 4 real-world projects:

SQL-Learning/
├── 01-Database-Basics/      # Intro to DBs, Tables, Primary & Foreign Keys
├── 02-DDL-Commands/         # CREATE, ALTER, DROP, TRUNCATE
├── 03-DML-Commands/         # INSERT, UPDATE, DELETE
├── 04-Select-Queries/       # SELECT, WHERE, ORDER BY, LIMIT
├── 05-Operators/            # Comparison, Logical, BETWEEN, IN, LIKE
├── 06-Aggregate-Functions/  # COUNT, SUM, AVG, MIN, MAX
├── 07-GROUPING/             # GROUP BY, HAVING
├── 08-JOINS/                # INNER, LEFT, RIGHT, FULL, SELF
├── 09-Subquery/             # Single Row, Multiple Row, Correlated
├── 10-Set-Operations/       # UNION, INTERSECT, EXCEPT
├── 11-Database-Relationships/# 1:1, 1:N, N:M
├── 12-Constraints/          # PK, FK, UNIQUE, NOT NULL, CHECK
├── 13-Indexes/              # Single & Composite Indexes
├── 14-Views/                # Virtual Tables
├── 15-Transactions/         # BEGIN, COMMIT, ROLLBACK
├── 16-PostgreSQL/           # JSONB, UUID, ENUM, ARRAY, CTE, Window Functions
├── 17-Optimization/         # EXPLAIN, ANALYZE, Query Tuning
├── 18-Real-Projects/        # Capstone Projects (Library, Student, E-Commerce, ERP)
└── datasets/                # Sample datasets for practice

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🗓️ Phase-Wise Learning Plan

Here is your structured learning roadmap to master SQL step-by-step:

Phase 1: SQL Foundation (১ সপ্তাহ)

শিখবে:

• Database কী, Table কী
• Row, Column
• Primary Key, Foreign Key

Practice:

CREATE DATABASE school_db;
CREATE TABLE students (
    id SERIAL PRIMARY KEY,
    name VARCHAR(100)
);

Phase 2: CRUD Operations (১ সপ্তাহ)

শিখবে: INSERT, SELECT, UPDATE, DELETE

Practice:

INSERT INTO students(name) VALUES('Atul');
SELECT * FROM students;

Phase 3: Filtering Data (১ সপ্তাহ)

শিখবে: WHERE, LIKE, IN, BETWEEN, ORDER BY, LIMIT

Practice:

SELECT * FROM students WHERE age > 18;

Phase 4: Aggregate Functions (৩ দিন)

শিখবে: COUNT(), SUM(), AVG(), MIN(), MAX()

Practice:

SELECT AVG(gpa) FROM students;

Phase 5: GROUP BY & HAVING (৩ দিন)

Practice:

SELECT department, COUNT(*)
FROM students
GROUP BY department;

Phase 6: JOINS (সবচেয়ে গুরুত্বপূর্ণ)

শিখবে: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN

Practice:

SELECT s.name, d.department_name
FROM students s
INNER JOIN departments d ON s.department_id = d.id;

Phase 7: Relationships

শিখবে: One To One, One To Many, Many To Many

💡 Pro Tip: এটা BrainCampus-এর মতো Project-এর জন্য খুব গুরুত্বপূর্ণ।

Phase 8: Advanced SQL

শিখবে: Subquery, CTE, Window Functions, Views

Phase 9: PostgreSQL Mastery

শিখবে: JSONB, UUID, ENUM, ARRAY, Triggers, Functions

💡 Pro Tip: BrainCampus-এর মতো Multi-Tenant System-এ এগুলো অনেক কাজে লাগবে।

Phase 10: Database Optimization

শিখবে: Index, Explain, Analyze, Query Optimization

⚠️ Note: ১ লাখ Student হলে Query Slow কেন হচ্ছে সেটা বুঝতে এই ফেজটি জরুরি।

Phase 11: Real Project Database Design

এই ৪টা Project Database নিজে Design করবে:

1. Student Management System
2. Library Management System
3. E-Commerce Database
4. School ERP Database

শেষে School ERP Database-এ যে বিষয়গুলো থাকবে: Schools, Sessions, Semesters, Students, Teachers, Results, Attendance, Fees, Exams.

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Happy Querying! 🎉