mysql -u root -p
use mysql;
select host, user from user;
create user '사용자'@'localhost(또는 %)' identified by '비밀번호';
drop user '사용자'@'localhost';
grant all privileges on *.* to '사용자'@'localhost';
grant all privileges on *.* to '사용자'@'localhost' identified by '비밀번호';
revoke all on DB이름.* from '사용자'@'localhost';
flush privileges;
show grants for '사용자명'@'localhost';