前言
一直以来，MySQL的应用和学习环境都是MySQL 5.6和之前的版本，也没有去关注新版本MySQL 5.7的变化和新特性。今天帮人处理忘记root密码的时时候，发现以前的方法不奏效了。
具体情况如下所示：
案例环境如下：
操作系统 ： Red Hat Enterprise Linux Server release 6.6 (Santiago)
数据库版本： 5.7.18 MySQL Community Server (GPL)
忘记密码，输入错误的密码时遇到下面错误信息：
| [root@mytestlnx02 ~]# mysql -u root -pEnter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)[root@mytestlnx02 ~]# |
检查MySQL服务是否启动，如果启动，关闭MySQL服务
| [root@mytestlnx02 ~]# ps -ef | grep -i mysqlroot 22972 1 0 14:18 pts/0 00:00:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock --pid-file=/var/run/mysqld/mysqld.pid --basedir=/usr --user=mysqlmysql 23166 22972 0 14:18 pts/0 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sockroot 23237 21825 0 14:22 pts/0 00:00:00 grep -i mysql[root@mytestlnx02 ~]# service mysqld stopStopping mysqld: [ OK ][root@mytestlnx02 ~]# |
找到MySQL的my.cnf配置文件，在/etc/my.cnf (有些版本是/etc/mysql/my.cnf）在里面增加下面一段信息：
| [mysqld] skip-grant-tables |
然后启动MySQL，进入MySQL后，修改root密码,操作过程中遇到ERROR 1054 (42S22): Unknown column 'password' in 'field list'，查了一下user表的表结构，发现原来MySQL 5.7下，user表已经没有Password字段。加密后的用户密码存储于authentication_string字段。
具体操作过程如下所示：
| [root@mytestlnx02 ~]# service mysqld startStarting mysqld: [ OK ][root@mytestlnx02 ~]# mysql -u root Welcome to the MySQL monitor. Commands end with ; or /g.Your MySQL connection id is 4Server version: 5.7.18 MySQL Community Server (GPL) Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners. Type 'help;' or '/h' for help. Type '/c' to clear the current input statement. mysql> use mysql;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -A Database changedmysql> update user set password=PASSWORD('Kd8k&dfdl023') -> where user='root';ERROR 1054 (42S22): Unknown column 'password' in 'field list'mysql> update mysql.user set authentication_string=password('Kd8k&dfdl023') where user='root';Query OK, 1 row affected, 1 warning (0.00 sec)Rows matched: 1 Changed: 1 Warnings: 1 mysql> flush privileges;Query OK, 0 rows affected (0.00 sec) mysql> exit |
