Amazon Redshift will no longer support the use of Python UDFs after June 30, 2026. We will start enforcing it in phases. For more information on the details of Python end of life and migration options, 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/) that was published on June 30, 2025. 

# Scalar SQL UDFs
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A scalar SQL UDF incorporates a SQL SELECT clause that runs when the function is called and returns a single value. The [CREATE FUNCTION](r_CREATE_FUNCTION.md) command defines the following parameters:
+ (Optional) Input arguments. Each argument must have a data type. 
+ One return data type.
+ One SQL SELECT clause. In the SELECT clause, refer to the input arguments using $1, $2, and so on, according to the order of the arguments in the function definition. 

The input and return data types can be any standard Amazon Redshift data type.

Don't include a FROM clause in your SELECT clause. Instead, include the FROM clause in the SQL statement that calls the SQL UDF. 

The SELECT clause can't include any of the following types of clauses:
+ FROM
+ INTO
+ WHERE
+ GROUP BY
+ ORDER BY
+ LIMIT