Beginner

185. IS NULL

Learn how to identify rows containing NULL values.

📘 Lesson 185 of 728 ⏱ 8 min 🎯 Beginner

IS NULL checks whether a column or expression contains a NULL value. NULL represents missing, unknown, or unavailable information.

Missing values are common in real-world datasets, and analysts need to identify them correctly.

Find employees whose manager information has not been recorded.

SQL 
SELECT
    EmployeeName,
    ManagerID
FROM Employees
WHERE ManagerID IS NULL;

IS NULL is widely used for data-quality checks, missing information analysis, exception reports, and incomplete records.

  • IS NULL checks for NULL values.
  • NULL is not the same as zero.
  • NULL is not the same as an empty string.
  • = NULL should not be used.
  • IS NULL is commonly used for missing-data analysis.
How do you check for NULL in SQL?

Use the IS NULL condition.

Can you use = NULL?

No. NULL should be checked using IS NULL because NULL represents an unknown value.

Have you finished this lesson?

Introduction to SQL – All Lessons