mysql SELECT/UPDATE command denied to user 'root'@'localhost' for table 'XXX'

1.mysql -u root -p
输入密码
2.GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON 数据库名.* TO 用户名@‘主机名’ identified by ‘数据库密码’;

GRANT all ON 数据库名.* TO 用户名@‘主机名’ identified by ‘数据库密码’;
3.flush privileges;
4.show grants for ‘用户名’@‘主机名’;

用户名：root
主机名：localhost