在Linux下安装了MySQL5.7.24，重新设置密码的时候竟然忘记root密码了，没办法，只能重新搞一下，亲测可用。
此处我用的是MySQL5.7.24的方法，其他版本的MySQL用这个方法或许不一样。
首先结束当前正在运行的mysql进程
linuxidc@linuxidc:~$ sudo /etc/init.d/mysql stop [ ok ] Stopping mysql (via systemctl): mysql.service.
用mysql安全模式运行并跳过权限验证
linuxidc@linuxidc:~$ sudo mysqld_safe --user=mysql --skip-grant-tables --skip-networking & [1] 22024 linuxidc@linuxidc:~$ 2018-11-01T08:39:38.987953Z mysqld_safe Logging to syslog. 2018-11-01T08:39:38.992011Z mysqld_safe Logging to '/var/log/mysql/error.log'. 2018-11-01T08:39:39.012604Z mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
用空密码方式使用root用户登录 MySQL
linuxidc@linuxidc:~$ sudo mysql -u root mysql Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A
Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 2 Server version: 5.7.24-0Ubuntu0.18.04.1 (Ubuntu)
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Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
更新密码
mysql> update user set Password = PASSWORD('root') where User ='root'; ERROR 1054 (42S22): Unknown column 'Password' in 'field list'
执行后报错 ERROR 1054(42S22) Unknown column 'password' in ‘field list’
错误的原因是MySQL 5.7版本下的mysql数据库下已经没有password这个字段了，password字段改成了authentication_string
所以请使用一下命令：
mysql> use mysql; Database changed
mysql> select User from user; #此处为查询用户命令 ------------------ | User | ------------------ | debian-sys-maint | | mysql.session | | mysql.sys | | root | ------------------ 4 rows in set (0.00 sec)
mysql> update mysql.user set authentication_string=password('root') where user='root'; #修改密码成功 Query OK, 1 row affected, 1 warning (0.11 sec) Rows matched: 1 Changed: 1 Warnings: 1
mysql> flush privileges; #刷新权限立即生效 Query OK, 0 rows affected (0.05 sec)
退出
mysql> quit Bye
