A '''User-Defined Function''', or '''UDF''', is a [[function (programming)|function]] provided by the user of a program or environment, in a context where the usual assumption is that functions are built into the program or environment.
==External links==
* [http://msdn.microsoft.com/library/en-us/tsqlref/ts_create_7r1l.asp Microsoft SQL Server reference for CREATE FUNCTION]
* [http://dev.mysql.com/doc/refman/5.0/en/adding-functions.html MySQL manual section on UDFs]
