如果不记得mysql的root密码，那么就只能强制修改密码了，使用shell轻松自动修改密码:

#!/bin/bash#Author AikerPATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/binexport PATHread -p "Please input your new password:" cpwd=$cservice mysqld stopmysqld_safe --skip-grant-tables&echo '正在修改密码...';echo 'The set password...';sleep 6mysql -uroot -e "insert into mysql.user(Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv,Reload_priv,Shutdown_priv,Process_priv,File_priv,Grant_priv,References_priv,Index_priv,Alter_priv,Show_db_priv,Super_priv,Create_tmp_table_priv,Lock_tables_priv,Execute_priv,Repl_slave_priv,Repl_client_priv,Create_view_priv,Show_view_priv,Create_routine_priv,Alter_routine_priv,Create_user_priv,Event_priv,Trigger_priv,Create_tablespace_priv,User,Password,host)values('Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','root',password('${pwd}'),'127.0.0.1')"mysql -uroot -e "insert into mysql.user(Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv,Reload_priv,Shutdown_priv,Process_priv,File_priv,Grant_priv,References_priv,Index_priv,Alter_priv,Show_db_priv,Super_priv,Create_tmp_table_priv,Lock_tables_priv,Execute_priv,Repl_slave_priv,Repl_client_priv,Create_view_priv,Show_view_priv,Create_routine_priv,Alter_routine_priv,Create_user_priv,Event_priv,Trigger_priv,Create_tablespace_priv,User,Password,host)values('Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','root',password('${pwd}'),'localhost')"mysql -uroot -e "UPDATE mysql.user SET password=PASSWORD('${pwd}') WHERE user='root'";mysql -uroot -e "UPDATE mysql.user SET authentication_string=PASSWORD('${pwd}') WHERE user='root'";mysql -uroot -e "FLUSH PRIVILEGES";pkill -9 mysqld_safepkill -9 mysqldsleep 2service mysqld startecho '==========================================='echo "mysql root密码成功修改为: ${pwd}"echo "The root password set ${pwd}  successuful"

测试效果：

[root@aaa ~]# sh mysqlpwd.sh Please input your new password:12345678Shutting down MySQL.. SUCCESS! 正在修改密码...The set password...2018-03-14T18:19:51.793872Z mysqld_safe Logging to '/data/mysql/aaa.err'.2018-03-14T18:19:51.814649Z mysqld_safe Starting mysqld daemon with databases from /data/mysqlERROR 1054 (42S22) at line 1: Unknown column 'Password' in 'field list'ERROR 1054 (42S22) at line 1: Unknown column 'Password' in 'field list'ERROR 1054 (42S22) at line 1: Unknown column 'password' in 'field list'mysqlpwd.sh: line 17: 45426 Killed                  mysqld_safe --skip-grant-tablesStarting MySQL SUCCESS! ===========================================mysql root密码成功修改为: 12345678The root password set 12345678  successuful[root@aaa ~]# mysql -uroot -p         Enter password: Welcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.21-log Source distributionCopyright (c) 2000, 2018, 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> quitBye