Centos7下忘记mysql5.7密码后，重置root密码的方式
Centos7下，忘记了MySQL的密码，不要急着重装。试试看下面的方法，完美解决。
编辑配置文件
[root@localhost ~]# vim /etc/my.cnf
在
[mysqld]配置节下新增skip-grant-tables配置项
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
skip-grant-tables
# Disabling symbolic-links is recommended to prevent assorted security risks
保存配置文件后，重启mysql服务。
[root@localhost ~]# systemctl restart mysqld.service
使用mysql命令登录mysql数据库。
[root@localhost ~]# mysql
使用下面语句修改root密码，注意和之前版本的mysql语句不太一样。
mysql>update mysql.user set authentication_string=password('新密码') where user='root' ;
mysql>flush privileges ;
mysql>quit
再次编辑mysql配置文件，将之前添加的 skip-grant-tables 去掉。
略
重启mysql服务后，使用新密码进行登录
[root@localhost ~]# systemctl restart mysqld.service