MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
The CREATE FUNCTION
statement is
used to create stored functions and user-defined functions (UDFs):
For information about creating stored functions, see Section 13.1.17, “CREATE PROCEDURE and CREATE FUNCTION Syntax”.
For information about creating user-defined functions, see Section 13.7.4.1, “CREATE FUNCTION Syntax for User-Defined Functions”.