CREATE ROLE IF NOT EXISTS role1 WITH ADMIN user1;
Warnings:
Note	1449	The user specified as a definer ('user1'@'%') does not exist
SELECT * FROM mysql.roles_mapping;
Host	User	Role	Admin_option
%	user1	role1	Y
DROP ROLE role1;
CREATE OR REPLACE ROLE role1 WITH ADMIN user2;
Warnings:
Note	1449	The user specified as a definer ('user2'@'%') does not exist
SELECT * FROM mysql.roles_mapping WHERE Role='role1';
Host	User	Role	Admin_option
%	user2	role1	Y
CREATE OR REPLACE ROLE role1 WITH ADMIN user3;
Warnings:
Note	1449	The user specified as a definer ('user3'@'%') does not exist
SELECT * FROM mysql.roles_mapping WHERE Role='role1';
Host	User	Role	Admin_option
%	user3	role1	Y
CREATE ROLE IF NOT EXISTS role1 WITH ADMIN user4;
Warnings:
Note	1449	The user specified as a definer ('user4'@'%') does not exist
Note	1975	Can't create role 'role1'; it already exists
SELECT * FROM mysql.roles_mapping WHERE Role='role1';
Host	User	Role	Admin_option
%	user3	role1	Y
DROP ROLE IF EXISTS role1;
SELECT * FROM mysql.roles_mapping WHERE Role='role1';
Host	User	Role	Admin_option
DROP ROLE IF EXISTS role1;
Warnings:
Note	1976	Can't drop role 'role1'; it doesn't exist
CREATE ROLE role_1;
CREATE ROLE IF NOT EXISTS role_1;
Warnings:
Note	1975	Can't create role 'role_1'; it already exists
CREATE OR REPLACE ROLE role_1;
CREATE OR REPLACE ROLE IF NOT EXISTS role_1;
ERROR HY000: Incorrect usage of OR REPLACE and IF NOT EXISTS
CREATE ROLE role_1;
ERROR HY000: Operation CREATE ROLE failed for 'role_1'
CREATE USER u1@localhost;
REVOKE SHOW DATABASES ON *.* FROM 'u1'@'localhost';
GRANT SHOW DATABASES ON *.* TO role_1;
GRANT role_1 TO u1@localhost;
connect  user_a, localhost, u1,,;
connection user_a;
SELECT CURRENT_USER;
CURRENT_USER
u1@localhost
SHOW DATABASES;
Database
information_schema
test
SELECT CURRENT_ROLE;
CURRENT_ROLE
NULL
SET ROLE role_1;
SELECT CURRENT_ROLE;
CURRENT_ROLE
role_1
SHOW DATABASES;
Database
information_schema
mtr
mysql
performance_schema
sys
test
SET ROLE NONE;
connect  user_b, localhost, root,,;
connection user_b;
# Clearing up
DROP ROLE role_1;
DROP ROLE IF EXISTS role_1;
Warnings:
Note	1976	Can't drop role 'role_1'; it doesn't exist
DROP ROLE role_1;
ERROR HY000: Operation DROP ROLE failed for 'role_1'
DROP USER u1@localhost;
CREATE ROLE r;
GRANT SHOW DATABASES ON *.* TO r;
CREATE USER foo;
CREATE USER bar;
GRANT r TO foo;
CREATE OR REPLACE USER foo IDENTIFIED WITH non_existing_plugin;
ERROR HY000: Plugin 'non_existing_plugin' is not loaded
DROP ROLE r;
DROP USER bar;