Over the last few weeks, I completed a small personal learning challenge:
Learn SQL fundamentals in 20 hours.
The idea was inspired by the concept from the book “The First 20 Hours: How to Learn Anything Fast.”
Instead of trying to master SQL in theory, I wanted to see what would happen if I simply spent focused time practicing it every day.
The goal wasn’t to become an SQL expert in 20 hours.
The goal was much simpler:
Build a solid foundation by writing SQL queries consistently.
To make the journey useful for others, I documented the entire learning process through a 20-day blog series and a GitHub repository containing all scripts.
This article serves as the index for the full SQL learning series.
Why I Started This Challenge
SQL is one of the most important skills in modern data and engineering workflows.
Whether you work in:
- Data Engineering
- Analytics
- Backend Development
- DevOps
- Cloud Engineering
You will eventually need to query, analyze, and understand data.
Even though I had some exposure to SQL earlier, I wanted to strengthen the fundamentals properly.
Instead of jumping randomly between tutorials, I created a structured learning path where each day focused on a specific concept.
Tools Used During the Journey
To keep the setup simple, I used lightweight tools:
- SQLite for the database
- Mac Terminal for running queries
- GitHub for storing scripts and examples
- Medium to document daily learning
This setup allowed me to focus on learning SQL itself, without worrying about heavy database installations.
You can explore all scripts here:
👉 GitHub Repository
https://github.com/kbrepository/learning-sql-fundamentals
What This SQL Learning Series Covers
The series starts with the absolute basics and gradually moves toward more practical topics like analytics queries and transactions.
Below is the complete roadmap.
The 20-Day SQL Learning Series
| Day | Topic | Article |
|---|---|---|
| Day 1 | SQL Setup & Basic SELECT | Read Article |
| Day 2 | Filtering Data with WHERE | Read Article |
| Day 3 | Sorting Data with ORDER BY | Read Article |
| Day 4 | Aggregations (COUNT, SUM, AVG) | Read Article |
| Day 5 | GROUP BY & HAVING | Read Article |
| Day 6 | INSERT Operations | Read Article |
| Day 7 | UPDATE & DELETE | Read Article |
| Day 8 | Subqueries | Read Article |
| Day 9 | JOINs (INNER & LEFT JOIN) | Read Article |
| Day 10 | Advanced JOIN Techniques | Read Article |
| Day 11 | Common Table Expressions (CTEs) | Read Article |
| Day 12 | Advanced CTE Usage | Read Article |
| Day 13 | Window Functions (ROW_NUMBER, RANK) | Read Article |
| Day 14 | Advanced Window Functions (LAG, LEAD) | Read Article |
| Day 15 | Creating SQL Views | Read Article |
| Day 16 | CASE Statements | Read Article |
| Day 17 | Constraints & Data Integrity | Read Article |
| Day 18 | Indexes & Performance Basics | Read Article |
| Day 19 | Transactions (BEGIN, COMMIT, ROLLBACK) | Read Article |
| Day 20 | SQL Capstone Project | Read Article |
Each article contains:
- explanations of the concept
- runnable SQL scripts
- command-line execution examples
- practical exercises
Why I Focused on Hands-On Learning
One thing I realized quickly during this challenge is that SQL is best learned by doing.
Reading about SQL concepts is helpful, but understanding really comes when you:
- run queries
- break things
- fix errors
- experiment with data
That’s why every blog in the series includes actual SQL scripts that can be executed directly in SQLite.
What I Personally Learned
This 20-hour challenge helped me:
- Understand SQL logic more clearly
- Get comfortable writing analytical queries
- Learn how joins and window functions actually work
- Understand performance basics like indexes
- Practice safe data operations using transactions
Most importantly, SQL started feeling logical instead of intimidating.
Who This Series Is For
This series is especially useful for:
- Beginners learning SQL
- Developers who want to strengthen database fundamentals
- Engineers moving toward data engineering
- Anyone who prefers hands-on learning
If you follow the scripts step by step, you will build a solid foundation in SQL.
Final Thoughts
This challenge reinforced a simple lesson:
Consistent practice beats long theoretical study.
Twenty hours is not enough to master SQL — but it is enough to build confidence and momentum.
If you are starting your SQL journey, I hope this series helps you take the first step.
📚 Explore the full series on Medium
👉 https://medium.com/@kalpeshbhangre96
💻 SQL scripts repository
👉 https://github.com/kbrepository/learning-sql-fundamentals
#SQL #LearningInPublic #DataEngineering #ContinuousLearning