Lectures

Find out what a CTE (Common Table Expressions) is in SQL, why you need them, how to use them, and how they’re different from subqueries. Simple examples, syntax, and tips for beginners.

Learn how to use CTEs (Common Table Expressions) to create temporary tables in SQL: benefits, syntax, comparison with temp tables, examples, and common mistakes.

Learn how to use CTEs (Common Table Expressions) for prepping and processing data in real SQL tasks: filtering, aggregation, metric calculation, and building reports — all with easy-to-follow examples.

Recursive CTEs are a powerful SQL tool for working with hierarchical data structures. In this material, you'll learn how recursive CTEs work, why you need them, how to use them to traverse trees and graphs, and you'll also see practical examples and common mistakes.

Learn how to use recursive CTEs in SQL to efficiently work with hierarchical structures, like a product category tree. This article gives you practical examples for building a tree, counting nesting levels, and creating a full category path.