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MySQL误删root用户怎么恢复

发布时间:2022-01-19 13:27:43 所属栏目:MySql教程 来源:互联网
导读:本篇内容介绍了MySQL误删root用户怎么恢复的有关知识,在实际案例的操作过程中,不少人都会遇到这样的困境,接下来就让小编带领大家学习一下如何处理这些情况吧!希望大家仔细阅读,能够学有所成! 一个朋友在领导要求他删除root@127.0.0.1,root@%等用户,
       本篇内容介绍了“MySQL误删root用户怎么恢复”的有关知识,在实际案例的操作过程中,不少人都会遇到这样的困境,接下来就让小编带领大家学习一下如何处理这些情况吧!希望大家仔细阅读,能够学有所成!
  
      一个朋友在领导要求他删除root@127.0.0.1,root@'%'等用户,只保留root@localhost时,
      他写了一条类似delete from mysql.user where user='root'的命令……
注意,他并没有写 “and host=”的条件,导致悲剧发生,并且还flush了授权。
 
以下模拟误删操作,尝试做恢复:
 
MySQL版本:
MySQL 5.5.49
 
模拟误删操作:
 
mysql> DELETE FROM mysql.user WHERE user='root';
Query OK, 1 row affected (0.01 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)
 
解决思路:
新安装或者初始化一个新的实例(与误删操作的MySQL版本最好一致)
初始化好后,启动实例,并以root@localhost用户登录,然后设置密码:
 
新实例上:
 
mysql> SELECT current_user();
+----------------+
| current_user() |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)
mysql> SET PASSWORD=password('123456');
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)
 
 
将存放在mysql.user里的root@localhost用户信息查询出:
 
mysql> SELECT * FROM mysql.user WHERE user='root' AND host='localhost' INTO OUTFILE '/tmp/root.txt';
Query OK, 1 row affected (0.00 sec)
 
 
对于误删操作的实例:
首先将之前查询出的/tmp/root.txt文件传到该机上,此处传到同目录下,操作略。
 
然后要停掉mysqld,并绕过授权表启动:
可能无法通过mysqladmin shutdown来停止,此处直接kill掉mysqld_safe与mysqld,操作略。
 
然后启动:
 
[root@vm02 ~]# mysqld_safe --skip-grant-tables &
[1] 2957
[root@vm02 ~]# 160819 17:00:30 mysqld_safe Logging to '/data/mysql_log/err-log.err'.
160819 17:00:30 mysqld_safe Starting mysqld daemon with databases from /data/mysql
 
进入mysql:
 
[root@vm02 ~]# mysql
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 3
Server version: 5.5.49-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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.
mysql> SELECT user(),current_user();
+--------+----------------+
| user() | current_user()  |
+--------+----------------+
| root@  | @               |
+--------+----------------+
1 row in set (0.00 sec)
 
可以查看一下mysql.user表,已经没有了误删的root用户,只剩下xxx@'ip1',yyy@'ip2',这样的业务用户:
 
mysql> SELECT user,host FROM mysql.user;
+------+---------------+
| user  | host          |
+------+---------------+
| xxx  | 192.168.1.185 |
| yyy  | 192.168.1.187 |
+------+---------------+
2 rows in set (0.00 sec)
 
将之前的新实例的mysql.user表中的root@localhost信息导入mysql.user:
 
 
mysql> LOAD DATA INFILE '/tmp/root.txt' INTO TABLE mysql.user;
Query OK, 1 row affected (0.04 sec)
Records: 1 Deleted: 0 Skipped: 0 Warnings: 0
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT user,host FROM mysql.user WHERE user='root' AND host='localhost';
+------+---------------+
| user | host          |
+------+---------------+
| root | localhost     |
+------+---------------+
1 rows in set (0.00 sec)
 
退出到shell环境,关闭以skip-grant-tables方式启动的mysqld:
此时已经可以用mysqladmin来关闭mysqld了:
 
[root@vm02 tmp]# mysqladmin -uroot -p123456 shutdown
160819 17:08:08 mysqld_safe mysqld from pid file /data/mysql/mysql-pid ended
[1]+  Done                    mysqld_safe --skip-grant-tables  (wd: ~)
(wd now: /tmp)
[root@vm02 tmp]# ps -ef|grep mysql
root       3938   1973  0 17:08 pts/0    00:00:00 grep mysql
 
再重新启动mysqld:
 
[root@vm02 tmp]# mysqld_safe &
[1] 3939
[root@vm02 tmp]# 160819 17:08:53 mysqld_safe Logging to '/data/mysql_log/err-log.err'.
160819 17:08:53 mysqld_safe Starting mysqld daemon with databases from /data/mysql
 
 
已经可以正常使用了,密码是之前在初始化的新实例设置的:
 
[root@vm02 tmp]# mysql -uroot -p123456
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 2
Server version: 5.5.49-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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.
mysql> SELECT user(),current_user();
+----------------+----------------+
| user()            | current_user()  |
+----------------+----------------+
| root@localhost | root@localhost  |
+----------------+----------------+
1 row in set (0.00 sec)
 
 
查看一下权限,可以对比一下,与之前的无异:
 
mysql> SHOW GRANTS;
+----------------------------------------------------------------------------------------------------------------------------------------+
| Grants for root@localhost                                                                                                              |
+----------------------------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' WITH GRANT OPTION |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION                                                                           |
+----------------------------------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
“MySQL误删root用户怎么恢复”的内容就介绍到这里了,感谢大家的阅读。

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