use test;
grant usage on *.* to dummy@localhost;
drop database if exists db1_secret;
create database db1_secret;
use db1_secret;
create table t1 ( u varchar(64), i int );
create procedure stamp(i int)
insert into db1_secret.t1 values (user(), i);
show procedure status like 'stamp';
Name	Type	Definer	Modified	Created	Security_type	Comment
stamp	PROCEDURE	root@localhost	0000-00-00 00:00:00	0000-00-00 00:00:00	DEFINER	
call stamp(1);
select * from t1;
u	i
root@localhost	1
call stamp(2);
select * from db1_secret.t1;
ERROR 42000: Access denied for user: 'dummy'@'localhost' to database 'db1_secret'
call stamp(3);
select * from db1_secret.t1;
ERROR 42000: Access denied for user: ''@'localhost' to database 'db1_secret'
select * from t1;
u	i
root@localhost	1
dummy@localhost	2
anon@localhost	3
alter procedure stamp sql security invoker;
show procedure status like 'stamp';
Name	Type	Definer	Modified	Created	Security_type	Comment
stamp	PROCEDURE	root@localhost	0000-00-00 00:00:00	0000-00-00 00:00:00	INVOKER	
call stamp(4);
select * from t1;
u	i
root@localhost	1
dummy@localhost	2
anon@localhost	3
root@localhost	4
call stamp(5);
ERROR 42000: Access denied for user: 'dummy'@'localhost' to database 'db1_secret'
call stamp(6);
ERROR 42000: Access denied for user: ''@'localhost' to database 'db1_secret'
drop procedure stamp;
use test;
drop database db1_secret;
delete from mysql.user where user='dummy';