What is a udf?

A User-Defined Function (UDF) is a customized function created by a user in a programming language, usually in SQL or Excel. It allows users to define their own functions to perform specific tasks that are not available in the standard library of functions.

UDFs can be used to simplify complex calculations, automate repetitive tasks, or manipulate data in a specific way. They can take inputs, perform operations, and return outputs based on the user-defined logic.

UDFs are often used in database management systems like MySQL or SQL Server to extend the functionality of the system and perform custom tasks that are not possible with built-in functions.

Overall, UDFs provide flexibility and customization for users to tailor their programs to specific requirements and perform specialized tasks efficiently.