Syntax:
ALTER {PROCEDURE | FUNCTION} sp_name [characteristic ...]

characteristic:
    { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
  | SQL SECURITY { DEFINER | INVOKER }
  | COMMENT 'string'

This statement can be used to change the characteristics of a stored
procedure or function. As of MySQL 5.0.3, you must have the ALTER
ROUTINE privilege for the routine. (That privilege is granted
automatically to the routine creator.) If binary logging is enabled,
this statement might also require the SUPER privilege, as described in
http://dev.mysql.com/doc/refman/5.0/en/stored-procedure-logging.html.

More than one change may be specified in an ALTER PROCEDURE or ALTER
FUNCTION statement.

URL: http://dev.mysql.com/doc/refman/5.0/en/alter-procedure.html

