---
title: "What is the purpose of the IS NULL and IS NOT NULL operators in SQL?"  
description: "What is the purpose of the IS NULL and IS NOT NULL operators in SQL?"  
author: "Revati S Misra"  
published: 2023-07-04  
updated: 2023-07-05  
canonical: https://www.mindstick.com/forum/158946/what-is-the-purpose-of-the-is-null-and-is-not-null-operators-in-sql  
category: "mssql server"  
tags: ["mssql server", "sql server", "sql"]  
reading_time: 3 minutes  

---

# What is the purpose of the IS NULL and IS NOT NULL operators in SQL?

What is the [purpose](https://yourviews.mindstick.com/view/247/no-fail-policy-failing-its-purpose) of the IS NULL and IS [NOT NULL](https://www.mindstick.com/interview/1933/what-is-not-null-constraint) [operators](https://www.mindstick.com/articles/716/php-operators) in [SQL](https://www.mindstick.com/articles/13115/types-of-keys-in-sql-or-oracle-database)?

## Replies

### Reply by Aryan Kumar

The `IS NULL` and `IS NOT NULL` operators in SQL are used to check if a value is [NULL](https://www.mindstick.com/forum/33922/how-to-use-null-coalescing-operator-in-c-sharp). A NULL value is a value that has no data. It is often used to represent missing data.

The `IS NULL` operator returns TRUE if the value is NULL, and FALSE if the value is not NULL. The `IS NOT NULL` operator returns FALSE if the value is NULL, and TRUE if the value is not NULL.

Here is an example of how the `IS NULL` operator can be used:

SQL

```plaintext
SELECT customer_name
FROM customers
WHERE email IS NULL;
```

This query will select the `customer_name` column from the `customers` table. The `IS NULL` operator will be used to check if the `email` column is NULL for each customer. If the `email` column is NULL for a customer, then the `customer_name` will be returned. If the `email` column is not NULL for a customer, then the `customer_name` will not be returned.

Here is an example of how the `IS NOT NULL` operator can be used:

SQL

```plaintext
SELECT customer_name
FROM customers
WHERE email IS NOT NULL;
```

This query will select the `customer_name` column from the `customers` table. The `IS NOT NULL` operator will be used to check if the `email` column is not NULL for each customer. If the `email` column is not NULL for a customer, then the `customer_name` will be returned. If the `email` column is NULL for a customer, then the `customer_name` will not be returned.

The `IS NULL` and `IS NOT NULL` operators can be used in a variety of ways to check for NULL values in a SQL database. They are a powerful tool that can be used to filter data, or to control the flow of a query.

Here are some other examples of how the `IS NULL` and `IS NOT NULL` operators can be used:

- To check if a customer has an email address.
- To check if a product is in stock.
- To check if a user is logged in.
- To check if a file exists.

The `IS NULL` and `IS NOT NULL` operators are versatile tools that can be used in a variety of ways to check for NULL values in a SQL database.


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Original Source: https://www.mindstick.com/forum/158946/what-is-the-purpose-of-the-is-null-and-is-not-null-operators-in-sql

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