SQL Interview Questions Series

6 books • PUBLIC

Practice SQL interview questions commonly asked at tech companies. Each book presents a real-world scenario, explains the underlying SQL pattern being tested, and provides a dataset to write your solution against. Topics covered include self-joins, window functions, gaps and islands, time-series comparisons, and aggregate filtering. Suitable for anyone preparing for data engineering, analytics, or backend engineering interviews where SQL proficiency is evaluated.

Mastering CTEs (Common Table Expressions)

5 books • PUBLIC

Learn to write clearer, more maintainable SQL queries with Common Table Expressions (CTEs). This collection shows practical examples of using CTEs to break down complex queries into logical steps, from simple filtering and aggregation to advanced patterns like recursive queries and gaps-and-islands problems. Each example includes working code you can run immediately in PostgreSQL, MySQL, Oracle, or MariaDB—no signup required. Whether you're analyzing time-series data, building hierarchical reports, or optimizing query performance, CTEs are an essential SQL skill.

SQL Challenge series

2 books • PUBLIC

Movies datasets

1 books • PUBLIC

Weekly collection of some interesting datasets and analysis