对于DBA来说,丢失超管用户root的密码是致命的,
可以通过添加--ship-grant-tables参数来跳过权限表。
1、忘记root密码,进不去数据库:
这个时候需要强制停库,先查看MySQL进程号
Kill掉MySQL进程,命令如下:
Kill完可以再查看是否还有进程
[root@tse2 tmp]# kill -9 9840 1
[root@tse2 tmp]# ps -ef |grep mysql
建议停库这种操作不要影响业务的情况下,停服操作的,还有最好这种密码记录好的,可以用keepass保存密码软件!
然后加跳过权限表参数,重启数据库。这样即使不输入密码,也可以进入数据库。
[root@tse2 bin]# mysqld_safe --defaults-file=/etc/my.cnf --skip-grant-tables &
[1] 4854
直接输入mysql不需要密码即可进入
给root用户设置新的密码并刷新权限,MySQL5.7之后,库下的password字段用authentication_string字段代替。
(product)root@localhost:mysql.sock [(none)]> use mysql;
Database changed
(product)root@localhost:mysql.sock [mysql]> update user set authentication_string=password("123456") where user="root";
Query OK, 0 rows affected, 1 warning (0.00 sec)
Rows matched: 1 Changed: 0 Warnings: 1
(product)root@localhost:mysql.sock [mysql]> flush privileges;
Query OK, 0 rows affected (0.00 sec)
设置完成之后,重启数据库。注意重启的时候不需要再加--skip-grant-tables参数了,正常启动服务,输入新的密码可以正常进入数据库了。这边重启以后测试直接mysql没有密码是无法进入的了。
[root@tse2 bin]# mysqld_safe --deaults-file=/etc/my.cnf &
[2] 6720
[root@tse2 bin]# 2020-01-16T02:55:45.223195Z mysqld_safe Logging to "/mysql/mysql3306/logs/error.log".
2020-01-16T02:55:45.262302Z mysqld_safe A mysqld process already exists
[2]+ Exit 1 mysqld_safe --deaults-file=/etc/my.cnf
[root@tse2 bin]# mysql
ERROR 1045 (28000): Access denied for user "root"@"localhost" (using password: NO)
这边输入密码连接,即可正常进入,是修改后的密码123456
[root@tse2 bin]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 4
Server version: 5.7.23-log MySQL Community Server (GPL)
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type "help;" or "h" for help. Type "c" to clear the current input statement.
(product)root@localhost:mysql.sock [(none)]> use mysql
Database changed
(product)root@localhost:mysql.sock [mysql]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.01 sec)