Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# Null condition
Null condition

The null condition tests for nulls, when a value is missing or unknown. 

## Syntax
Syntax

```
expression IS [ NOT ] NULL
```

## Arguments
Arguments

 *expression*   
Any expression such as a column. 

IS NULL   
Is true when the expression's value is null and false when it has a value. 

 IS NOT NULL   
Is false when the expression's value is null and true when it has a value. 

## Example
Example

This example indicates how many times the SALES table contains null in the QTYSOLD field: 

```
select count(*) from sales
where qtysold is null;
count
-------
0
(1 row)
```