MySQL WHERE Clause: Handling NULL Values
Quick Answer
In MySQL, NULL represents missing or unknown data and requires special handling in WHERE clauses. Use IS NULL or IS NOT NULL to filter NULL values, as standard comparison operators (=, <>) do not work with NULL. Understanding NULL handling is essential for accurate query results.
Learning Objectives
- Understand what NULL means in MySQL and how it differs from other values.
- Learn how to correctly filter NULL values using the WHERE clause.
- Identify common mistakes when comparing NULL values in SQL queries.
Introduction
In MySQL, NULL is a special marker used to indicate that a data value does not exist in the database.
Handling NULL values in queries requires understanding how SQL treats NULL differently from other values.
NULL is not a value, it is the absence of a value.





