SQL • LESSON 31

Common Table Expressions

Learn how to organize complex SQL queries using reusable query blocks.

🔴 Advanced⏱ 3 Minutes⭐ 490 XP
🤔 THE QUESTION

How can we break a complex SQL query into smaller, easier-to-understand steps?

💡 WHAT IS IT?

A Common Table Expression, or CTE, creates a temporary named result that can be referenced by the main query.

🎯 WHAT IS IT USED FOR?

CTEs are useful for making complex queries easier to read, organizing multi-step logic, and reusing intermediate query results.

💻 EXAMPLE
WITH high_paid AS (
  SELECT name,
  salary
  FROM employees
  WHERE salary > 100000
)
SELECT *
FROM high_paid;

Mission Brief

Practice creating a CTE to identify employees whose salary is above 100000.

Objectives

  • ✓ WITH
  • ✓ CTE
  • ✓ SELECT
  • ✓ Filtering
  • ✓ Query organization
🚀 Start Mission