话不多说直接写解决方案：
环境：centos7
数据库：mariadb
1.关闭mysql服务
[root@a ~]# systemctl stop mariadb
2.kill掉mysql进程
[root@a ~]# ps -ef |grep mariadb root 8438 8420 0 06:22 pts/0 00:00:00 grep --color=auto mariadb [root@a ~]# kill 8420
3.修改mysql配置文件添加skip-grant-tables
[root@a ~]# vi /etc/my.cnf [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock skip-grant-tables # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 # Settings user and group are ignored when systemd is used. # If you need to run mysqld under a different user or group, # customize your systemd unit file for mariadb according to the # instructions in http://fedoraproject.org/wiki/Systemd [mysqld_safe] log-error=/var/log/mariadb/mariadb.log pid-file=/var/run/mariadb/mariadb.pid # # include all files from the config directory # !includedir /etc/my.cnf.d
4.重启服务无密码登录
[root@a ~]# systemctl restart mariadb [root@a ~]# mysql -uroot Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 2 Server version: 5.5.64-MariaDB MariaDB Server Copyright (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)]>
5.在mysql里面就可以重新设置密码了
MariaDB [(none)]> update mysql.user set Password=password('a') where User='root'; Query OK, 0 rows affected (0.00 sec) Rows matched: 4 Changed: 0 Warnings: 0
6.登录成功
[root@a ~]# mysql -uroot -pa Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 3 Server version: 5.5.64-MariaDB MariaDB Server Copyright (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)]>
