Procedure Function MySQL Tutorial

This statement can be used to change the characteristics of a stored procedure or function.
More than one change may be specified in an ALTER PROCEDURE or ALTER FUNCTION statement.

ALTER {PROCEDURE | FUNCTION} sp_name [characteristic ...]
characteristic:
    { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
  | SQL SECURITY { DEFINER | INVOKER }
  | COMMENT 'string'