use mysql;
create database MYSQLtest;
grant all on MySQLtest.* to mysqltest_1@localhost;
show grants for mysqltest_1@localhost;
Grants for mysqltest_1@localhost
GRANT USAGE ON *.* TO 'mysqltest_1'@'localhost'
GRANT ALL PRIVILEGES ON `mysqltest`.* TO 'mysqltest_1'@'localhost'
select * from db where user = 'mysqltest_1';
Host	Db	User	Select_priv	Insert_priv	Update_priv	Delete_priv	Create_priv	Drop_priv	Grant_priv	References_priv	Index_priv	Alter_priv	Create_tmp_table_priv	Lock_tables_priv	Create_view_priv	Show_view_priv	Create_routine_priv	Alter_routine_priv	Execute_priv
localhost	mysqltest	mysqltest_1	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y
update db set db = 'MYSQLtest' where db = 'mysqltest' and user = 'mysqltest_1' and host = 'localhost';
flush privileges;
show grants for mysqltest_1@localhost;
Grants for mysqltest_1@localhost
GRANT USAGE ON *.* TO 'mysqltest_1'@'localhost'
GRANT ALL PRIVILEGES ON `mysqltest`.* TO 'mysqltest_1'@'localhost'
select * from db where user = 'mysqltest_1';
Host	Db	User	Select_priv	Insert_priv	Update_priv	Delete_priv	Create_priv	Drop_priv	Grant_priv	References_priv	Index_priv	Alter_priv	Create_tmp_table_priv	Lock_tables_priv	Create_view_priv	Show_view_priv	Create_routine_priv	Alter_routine_priv	Execute_priv
localhost	MYSQLtest	mysqltest_1	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y
delete from db where db = 'MYSQLtest' and user = 'mysqltest_1' and host = 'localhost';
flush privileges;
drop user mysqltest_1@localhost;
drop database MYSQLtest;