SQL • LESSON 29

CASE Expressions

Learn how to create conditional logic directly inside SQL queries.

🔴 Advanced⏱ 3 Minutes⭐ 450 XP
🤔 THE QUESTION

How can we categorize employees based on their salary?

💡 WHAT IS IT?

CASE lets SQL evaluate conditions and return different values depending on which condition is true.

🎯 WHAT IS IT USED FOR?

CASE is useful for creating categories, labels, business rules, conditional calculations, and readable reports directly inside a query.

💻 EXAMPLE
SELECT
name,
salary,
CASE
  WHEN salary >= 100000 THEN 'High'
  WHEN salary >= 50000 THEN 'Medium'
  ELSE 'Low'
END AS salary_level
FROM employees;

Mission Brief

Practice using CASE to categorize employees into salary levels.

Objectives

  • ✓ SELECT
  • ✓ CASE
  • ✓ WHEN
  • ✓ THEN
  • ✓ ELSE
  • ✓ END
🚀 Start Mission