Zero to Pro with Easy-to-Insane Coding Challenges

🚀 7 Days SQL Bootcamp: From Zero to Pro – Easy to Ultra-Hard Coding Challenges

Are you ready to transform your SQL skills in just 7 days? Whether you’ve never written a query before or you already know the basics, this intense practice-driven bootcamp will take you on a journey from simple SELECT statements all the way to jaw-dropping, ultra-hard SQL challenges that even experienced developers struggle with.

This isn’t just another tutorial – it’s a battlefield of SQL problems carefully designed to push your limits. Every day, you’ll level up with progressively harder coding questions, starting with easy filtering queries and ending with mind-bending problems involving recursion, window functions, query optimization, and multi-level joins.

By the end of this 7-day bootcamp, you won’t just know SQL – you’ll think in SQL. And if you can solve our final-day challenges, you can solve any SQL problem thrown at you in real life. 💪

🔥 What You’ll Experience

• Day 1–2: Zero to Basics → SELECT, WHERE, ORDER BY, GROUP BY.
• Day 3–4: Intermediate Level → JOINS, subqueries, aggregations, CTEs.
• Day 5–6: Advanced Level → Window functions, pivots, ranking, performance tricks.
• Day 7: Ultra-Hard SQL Battles → Questions designed to challenge even pros.

⚔️ Example Ultra-Hard SQL Questions You’ll Face

1. Recursive Employee Hierarchy Puzzle

Given a table Employees(emp_id, emp_name, manager_id, salary),

Write a query to print the entire company hierarchy (CEO → Managers → Employees) with proper indentation showing levels. Bonus: Also calculate the cumulative salary budget at each level.

1. Nth Highest Salary in Each Department Without Using LIMIT or RANK()

Given a table Salaries(emp_id, dept_id, salary),

Write a query to find the 3rd highest salary in every department without using LIMIT, OFFSET, or ranking functions.

1. Challenging Gaps & Islands Problem

You are given a table Logins(user_id, login_date) with daily login records.

Write a query to find all continuous streaks of login days per user and output (user_id, start_date, end_date, streak_length).

1. Palindromic String Challenge with SQL Only

Given a table Words(word),

Write a query to find all words that are palindromes using SQL only (no procedural code).

1. Impossible-Sounding Query – Yet Solvable!

A table Orders(order_id, customer_id, order_date, amount) is given.

Write a query to find the top customer in each month whose spending increased compared to the previous month, using only SQL window functions.

💡 Can You Solve These? If you can crack the Day 7 Ultra Challenges, you’ll prove that you’re not just a beginner anymore – you’re a SQL Warrior.

👉 Join the 7-Day SQL Bootcamp and see how far you can go. By the end, you won’t just answer SQL interview questions – you’ll master them.