创建新用户
insert into mysql.user(host, user, password)
values("localhost", "dev", password("admin"))
刷新系统权限表
mysql>flush privileges;
授权min用户拥有tree数据库的所有权限
mysq>grant all privileges on tree.* to dev@localhost identified by 'admin';
删除用户
mysql>DELETE FROM mysql.user WHERE User="dev" and Host="localhost";
修改用户密码
mysql>update mysql.user set password=password('123456')
where User="dev" and Host="localhost";