ALTER FUNCTION func_name [characteristic ...]

characteristic: {
    COMMENT 'string'
  | LANGUAGE {SQL | JAVASCRIPT}
  | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
  | SQL SECURITY { DEFINER | INVOKER }
  | USING([library_reference][, library_reference][, ...])
}

This statement can be used to change the characteristics of a stored function. More than one change may be specified in an ALTER FUNCTION statement. However, you cannot change the parameters or body of a stored function using this statement; to make such changes, you must drop and re-create the function using DROP FUNCTION and CREATE FUNCTION.

You must have the ALTER ROUTINE privilege for the function. (That privilege is granted automatically to the function creator.) If binary logging is enabled, the ALTER FUNCTION statement might also require the SUPER privilege, as described in Section 27.8, “Stored Program Binary Logging”.

The USING clause is specific to stored programs written in JavaScript (see Section 27.3, “JavaScript Stored Programs”), and allows you to specify a list of zero or more libraries to be imported by the stored function, causing any previous such list to be removed, just as it does with ALTER PROCEDURE. See Section 15.1.8, “ALTER PROCEDURE Statement”, for more detailed information.