Beginner

82. IS NULL

Learn how to find rows containing NULL values using IS NULL.

📘 Lesson 82 of 728 ⏱ 7 min 🎯 Beginner

The IS NULL operator checks whether a column contains a NULL value. Because NULL represents an unknown value, it cannot be compared using the normal equals operator.

Analysts frequently need to identify missing information for data-quality checks, incomplete records, and business reporting.

If some employees do not have a manager assigned, IS NULL can identify those employee records.

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

IS NULL is useful for finding missing customer details, incomplete employee records, missing transaction information, and data-quality issues.

  • IS NULL checks for NULL values.
  • Use IS NULL instead of = NULL.
  • It is commonly used for data-quality checks.
  • It can be combined with other conditions.
  • It filters rows containing missing values.
How do you check for NULL in SQL?

Use the IS NULL operator.

Can you use = NULL to find NULL values?

No. SQL uses IS NULL to test whether a value is NULL.

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