create user 'test_user'@'localhost';
create role test_role1;
create role test_role2;
insert into mysql.roles_mapping (HostFk, UserFk, RoleFk) values ('localhost',
'test_user',
'test_role1');
insert into mysql.roles_mapping (HostFk, UserFk, RoleFk) values ('localhost',
'test_user',
'test_role2');
insert into mysql.roles_mapping (HostFk, UserFk, RoleFk) values ('',
'test_role1',
'test_role2');
select user, host from mysql.user where user not like 'root';
user	host
test_role1	
test_role2	
test_user	localhost
select * from mysql.roles_mapping;
HostFk	UserFk	RoleFk
	test_role1	test_role2
localhost	test_user	test_role1
localhost	test_user	test_role2
flush privileges;
select user, host from mysql.db;
user	host
	%
	%
grant select on mysql.* to test_role2;
flush privileges;
show grants;
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
select current_user(), current_role();
current_user()	current_role()
test_user@localhost	NULL
set role test_role1;
select current_user(), current_role();
current_user()	current_role()
test_user@localhost	test_role1
show grants;
Grants for test_user@localhost
GRANT SELECT ON `mysql`.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_role1'
GRANT USAGE ON *.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_role1'
GRANT test_role2 TO 'test_user'@'localhost'
set role none;
select current_user(), current_role();
current_user()	current_role()
test_user@localhost	NULL
show grants;
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for test_user@localhost;
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for test_role1;
ERROR 42000: Access denied for user 'test_user'@'localhost' to database 'mysql'
show grants for test_role2;
ERROR 42000: Access denied for user 'test_user'@'localhost' to database 'mysql'
show grants for CURRENT_USER;
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for CURRENT_USER();
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for CURRENT_ROLE;
ERROR 42000: There is no such grant defined for user 'test_user' on host 'localhost'
show grants for CURRENT_ROLE();
ERROR 42000: There is no such grant defined for user 'test_user' on host 'localhost'
set role test_role2;
select current_user(), current_role();
current_user()	current_role()
test_user@localhost	test_role2
show grants;
Grants for test_user@localhost
GRANT SELECT ON `mysql`.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for test_user@localhost;
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for test_role1;
Grants for test_role1
GRANT SELECT ON `mysql`.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_role1'
GRANT USAGE ON *.* TO 'test_role2'
GRANT test_role2 TO 'test_role1'
show grants for test_role2;
Grants for test_role2
GRANT SELECT ON `mysql`.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_role2'
show grants for CURRENT_USER;
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for CURRENT_USER();
Grants for test_user@localhost
GRANT USAGE ON *.* TO 'test_user'@'localhost'
GRANT test_role1 TO 'test_user'@'localhost'
GRANT test_role2 TO 'test_user'@'localhost'
show grants for CURRENT_ROLE;
Grants for test_role2
GRANT SELECT ON `mysql`.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_role2'
show grants for CURRENT_ROLE();
Grants for test_role2
GRANT SELECT ON `mysql`.* TO 'test_role2'
GRANT USAGE ON *.* TO 'test_role2'
drop user 'test_user'@'localhost';
revoke select on mysql.* from test_role2;
drop role test_role1;
drop role test_role2;
delete from mysql.roles_mapping where RoleFk='test_role1';
delete from mysql.roles_mapping where RoleFk='test_role2';
flush privileges;