IS NULL is a SQL condition used to determine whether a column contains a NULL value. Because NULL represents an unknown or missing value, it cannot be checked using the normal equality operator.
Finding missing data is an important part of data cleaning and quality analysis.
An analyst may need to identify customers whose email address has not been provided.
SELECT
CustomerID,
CustomerName
FROM Customers
WHERE Email IS NULL;IS NULL is used in data-quality checks, customer analysis, employee records, financial reporting, and database validation.
- IS NULL checks for missing values.
- Use IS NULL instead of = NULL.
- It can be used in WHERE conditions.
- It is useful for data-quality analysis.
- NULL handling is important in SQL.
How do you check for NULL in SQL?
Use the IS NULL condition.
Why should you not use = NULL?
NULL represents an unknown value, so normal equality comparison does not correctly identify NULL values.