概述

丢失root密码，意味着不能以超级管理员帐号登录数据库，进行维护工作。需要找回root密码。

处理方法

杀掉mysql进程，然后添加一个参数–skip-grant-tables跳过权限表，启动mysql实例，然后以无密码方式登录数据库，修改root用户密码，再关闭mysql实例（关闭或者kill mysql进程），最后正常启动mysql实例，就可以使用root用户登录数据库了。

关键操作代码

点击阅读原文，提升阅读体验：https://www.modb.pro/db/22826?cyn

mysql -uroot -p

ps -ef|grep mysql

kill -9 mysql进程号

mysqld_safe --defaults-file=/etc/f --skip-grant-tables &

mysql

use mysql；

update user set authentication_string=password(‘oracle123’) where user=‘root’;

flush privileges;

mysqladmin -p shutdown

mysqld_safe --defaults-file=/etc/f &

mysql -uroot -p

操作演示日志

[root@source~]#mysql-uroot-pEnterpassword:ERROR1045(28000):Accessdeniedforuser'root'@'localhost'(usingpassword:YES)==故意输错密码，模拟root密码丢失==[root@source~]#[root@source~]#ps-ef|grepmysqlroot67336191010:28pts/000:00:00/bin/sh/usr/local/mysql/bin/mysqld_safe--defaults-file=/etc/fmysql70296733211:10pts/000:00:00/usr/local/mysql/bin/mysqld--defaults-file=/etc/f--basedir=/usr/local/mysql--datadir=/data/mysql--plugin-dir=/usr/local/mysql/lib/plugin--user=mysql--log-error=source.err--pid-file=source.pid--port=3306root70636191011:10pts/000:00:00grepmysql[root@source~]#[root@source~]#kill-970296733[root@source~]#[1]+Killedmysqld_safe--defaults-file=/etc/f[root@source~]#[root@source~]#ps-ef|grepmysqlroot70666191011:10pts/000:00:00grepmysql[root@source~]#[root@source~]#[root@source~]#mysqld_safe--defaults-file=/etc/f--skip-grant-tables&[1]7286[root@source~]#-02-16T03:11:41.998645Zmysqld_safeLoggingto'/data/mysql/source.err'.-02-16T03:11:42.020962Zmysqld_safeStartingmysqlddaemonwithdatabasesfrom/data/mysql[root@source~]#[root@source~]#mandsendwith;or\g.YourMySQLconnectionidis3Serverversion:5.7.20-logMySQLCommunityServer(GPL)Copyright(c)2000,,Oracleand/oritsaffiliates.Allrightsreserved.OracleisaregisteredtrademarkofOracleCorporationand/oritsaffiliates.Othernamesmaybetrademarksoftheirrespectiveowners.Type'help;'or'\h'forhelp.Type'\c'toclearthecurrentinputstatement.root@db11:11:[(none)]>root@db11:11:[(none)]>root@db11:12:[(none)]>root@db11:12:[(none)]>usemysql;Databasechangedroot@db11:12:[mysql]>root@db11:12:[mysql]>updateusersetauthentication_string=password('oracle123')whereuser='root';==修改密码==QueryOK,1rowaffected,1warning(0.01sec)Rowsmatched:2Changed:1Warnings:1root@db11:13:[mysql]>root@db11:13:[mysql]>flushprivileges;QueryOK,0rowsaffected(0.00sec)root@db11:13:[mysql]>root@db11:14:[mysql]>exitBye[root@source~]#[root@source~]#mysqladmin-pshutdownEnterpassword:[root@source~]#[root@source~]#-02-16T03:15:27.217666Zmysqld_safemysqldfrompidfile/data/mysql/source.pidended[1]+Donemysqld_safe--defaults-file=/etc/f--skip-grant-tables[root@source~]#[root@source~]#ps-ef|grepmysqlroot75026191011:15pts/000:00:00grepmysql[root@source~]#[root@source~]#mysqld_safe--defaults-file=/etc/f&[1]7503[root@source~]#-02-16T03:15:57.181920Zmysqld_safeLoggingto'/data/mysql/source.err'.-02-16T03:15:57.217614Zmysqld_safeStartingmysqlddaemonwithdatabasesfrom/data/mysql[root@source~]#[root@source~]#mysql-uroot-pEnterpassword:==root密码找回后，正常登录==mandsendwith;or\g.YourMySQLconnectionidis4Serverversion:5.7.20-logMySQLCommunityServer(GPL)Copyright(c)2000,,Oracleand/oritsaffiliates.Allrightsreserved.OracleisaregisteredtrademarkofOracleCorporationand/oritsaffiliates.Othernamesmaybetrademarksoftheirrespectiveowners.Type'help;'or'\h'forhelp.Type'\c'toclearthecurrentinputstatement.root@db11:16:[(none)]>