mysql错误ERROR 1044 (42000): Access denied for user

mysql错误ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'MAC'解决办法

MariaDB [(none)]> create database MAC;ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'MAC'MariaDB [(none)]> 方法一：1.关闭mysql   # service mysqld stop 【 备注centos7是systemctl stop mariadb】2.屏蔽权限   # mysqld_safe --skip-grant-table   屏幕出现： Starting demo from .....3.新开起一个终端输入   #mysql -uroot -pxxxxxx   MariaDB [(none)]> use mysql;   MariaDB [mysql]>    MariaDB [mysql]> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';     【备注：下一次会用newpassword密码登录数据库】   MariaDB [mysql]>  FLUSH PRIVILEGES;//记得要这句话，否则如果关闭先前的终端，又会出现原来的错误   MariaDB [mysql]>  \q----------------------------------------------------------------------------我的实操测试[root@nessus ~]# systemctl stop mysqldFailed to stop mysqld.service: Unit mysqld.service not loaded.[root@nessus ~]# systemctl stop mariadb[root@nessus ~]# [root@nessus ~]# [root@nessus ~]# mysqld_safe --skip-grant-table191030 11:11:24 mysqld_safe Logging to '/var/log/mariadb/mariadb.log'.191030 11:11:24 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql新开起一个终端输入[root@nessus ~]# mysql -uroot  【我的无密码】MariaDB [(none)]> use mysql;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedMariaDB [mysql]> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';Query OK, 4 rows affected (0.01 sec)Rows matched: 4  Changed: 4  Warnings: 0MariaDB [mysql]> MariaDB [mysql]> MariaDB [mysql]> FLUSH PRIVILEGES;Query OK, 0 rows affected (0.00 sec)MariaDB [mysql]> \qBye[root@nessus ~]# mysql -uroot  【发现之前无密码无法登陆了】ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)[root@nessus ~]# [root@nessus ~]# mysql -uroot -pnewpassword   【得用newpassword密码登录数据库】Welcome to the MariaDB monitor.  Commands end with ; or \g.Your MariaDB connection id is 5Server version: 5.5.60-MariaDB MariaDB ServerCopyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.MariaDB [(none)]> MariaDB [(none)]> MariaDB [(none)]> MariaDB [(none)]> create database MAC;Query OK, 1 row affected (0.00 sec)MariaDB [(none)]> MariaDB [(none)]> MariaDB [(none)]> MariaDB [(none)]>