SQL • LESSON 24

UNION ALL

Learn how to combine multiple SELECT results while preserving duplicates.

🔴 Advanced⏱ 3 Minutes⭐ 430 XP
🤔 THE QUESTION

How can we combine employee and contractor results while keeping duplicate names?

💡 WHAT IS IT?

UNION ALL combines the results of multiple SELECT statements and keeps every row, including duplicates.

🎯 WHAT IS IT USED FOR?

It is useful when you need to combine similar datasets and every record matters. Unlike UNION, UNION ALL does not remove duplicate rows.

💻 EXAMPLE
SELECT name
FROM employees

UNION ALL

SELECT name
FROM contractors;

Mission Brief

Practice using UNION ALL to combine employee and contractor names while preserving duplicate values.

Objectives

  • ✓ SELECT
  • ✓ UNION ALL
  • ✓ Multiple queries
  • ✓ Result sets
  • ✓ Duplicate preservation
🚀 Start Mission