SQL IS NULL

Last Updated : 24 Aug, 2026

The SQL IS NULL operator checks whether a column contains a NULL (missing or unknown) value. Since NULL is not the same as zero or an empty string.

  • Check multiple columns using OR.
  • Filter rows before applying UPDATE or DELETE.

Example: First, we create a demo SQL database and table, on which we will use the IS NULL command.

1

Query:

SELECT * FROM customers
WHERE email IS NULL;

Output:

2

Syntax

SELECT column_name
FROM table_name
WHERE column_name IS NULL;

Note: COUNT(column) ignores NULL values, while COUNT(*) counts rows filtered using IS NULL.

Working

First, we will create a demo SQL database and table, on which we will use the IS NULL operator.

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Example 1: IS NULL Operator on Multiple Columns

We need to filter rows where either email or coding_score is NULL, use the OR operator:

Query:

SELECT * 
FROM geeksforgeeks
WHERE email IS NULL OR coding_score IS NULL;

Output:

out-1

Example 2: IS NULL with COUNT() Function

In this Query, count how many rows have a NULL value in the coding_score column.

SELECT COUNT(*) AS count_empty_coding_score
FROM geeksforgeeks
WHERE coding_score IS NULL;

Output:

Out-3

Example 3: IS NULL with UPDATE Statement

In this Query, we set a default email for all users with a NULL value in the email column

Query:

UPDATE geeksforgeeks
SET email = 'default@gmail.com'
WHERE email IS NULL;

Output:

out-5

Example 4: IS NULL with DELETE Statement

We can also use the IS NULL operator to delete rows where a column contains NULL values. For example, to delete rows where coding_score is NULL

Query:

DELETE FROM geeksforgeeks
WHERE coding_score IS NULL;

Output:

out-8

Note: A NULL value is different from a Zero Value and Blank Spaces. A field that has NULL value means the field was left blank.

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