MySQL 误删用户

误删除root用户&误删除所有用户

 #-------------------------------------------------------------------------------
 #忘记root密码 登录并修改root密码 beign
 #-------------------------------------------------------------------------------

 mysqld_safe --skip-grant-tables --skip-networking &
 [root@db01-sa ~]# mysql
 Welcome to the MySQL monitor.  Commands end with ; or \g.
 Your MySQL connection id is 1
 Server version: 5.6.38 Source distribution

 Copyright (c) 2000, 2017, 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> use mysql;
 Reading table information for completion of table and column names
 You can turn off this feature to get a quicker startup with -A

 Database changed
 mysql> update user set password=PASSWORD('') where user='root' and host='localhost';
 Query OK, 1 row affected (0.98 sec)
 Rows matched: 1  Changed: 1  Warnings: 0

 [root@db01-sa ~]# /etc/init.d/mysqld restart
 Shutting down MySQL.. SUCCESS!
 Starting MySQL.180620 13:09:10 mysqld_safe mysqld from pid file /application/mysql/data/db01-sa.pid ended
 .... SUCCESS!
 []+  Done                    mysqld_safe --skip-grant-tables --skip-networking

 [root@db01-sa ~]# mysql -uroot -p123
 Warning: Using a password on the command line interface can be insecure.
 Welcome to the MySQL monitor.  Commands end with ; or \g.
 Your MySQL connection id is 2
 Server version: 5.6.38 Source distribution

 Copyright (c) 2000, 2017, 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> 

 #-------------------------------------------------------------------------------
 #忘记root密码 登录并修改root密码 end
 #-------------------------------------------------------------------------------

 #-------------------------------------------------------------------------------
 #误删除所有用户 beign
 #-------------------------------------------------------------------------------

 #模拟情况
 select user,host,password from mysql.user;
 mysql> drop user root@'localhost';

 #开始处理
 [root@db01-sa ~]# /etc/init.d/mysqld stop
 [root@db01-sa ~]#mysqld_safe --skip-grant-tables --skip-networking &
 [root@db01-sa ~]# mysql

 mysql> INSERT INTO mysql.user VALUES ('localhost','root',
     -> '','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',
     -> '','','','',0,0,0,0,'mysql_native_password','','N');
 Query OK, 1 row affected (0.00 sec)

 mysql> update mysql.user set password=PASSWORD('') where user='root';
 Query OK, 1 row affected (0.00 sec)
 Rows matched: 1  Changed: 1  Warnings: 0

 mysql> select user,host,password from mysql.user;
 +------+-----------+-------------------------------------------+
 | user | host      | password                                  |
 +------+-----------+-------------------------------------------+
 | root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
 +------+-----------+-------------------------------------------+
 row in set (0.08 sec)

 [root@db01-sa ~]# /etc/init.d/mysqld restart
 Shutting down MySQL..180620 13:19:15 mysqld_safe mysqld from pid file /application/mysql/data/db01-sa.pid ended
  SUCCESS!
 Starting MySQL..... SUCCESS!
 []+  Done                    mysqld_safe --skip-grant-tables --skip-networking
 [root@db01-sa ~]# mysql
 ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
 [root@db01-sa ~]# mysql -uroot -p123
 Warning: Using a password on the command line interface can be insecure.
 Welcome to the MySQL monitor.  Commands end with ; or \g.
 Your MySQL connection id is 2
 Server version: 5.6.38 Source distribution

 Copyright (c) 2000, 2017, 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,host,password from mysql.user;
 +------+-----------+-------------------------------------------+
 | user | host      | password                                  |
 +------+-----------+-------------------------------------------+
 | root | localhost | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
 +------+-----------+-------------------------------------------+
 1 row in set (0.00 sec)

 #-------------------------------------------------------------------------------
 #误删除所有用户 end
 #-------------------------------------------------------------------------------

其实做到以上下面的就不用看了

############################################################################

如果遇到以上处理权限不足的补充处理

----add begin  by nod 18-06-21------

备注：可能会有权限不够的情况
处理方式：

INSERT INTO mysql.user VALUES ('localhost','root',
'','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',
'','','','',0,0,0,0,'mysql_native_password','','N');

mysql> update mysql.user set password=PASSWORD('') where user='root';

[root@db01-sa ~]# /etc/init.d/mysqld restart
Shutting down MySQL..180621 08:08:27 mysqld_safe mysqld from pid file /application/mysql/data/db01-sa.pid ended
 SUCCESS!
Starting MySQL..... SUCCESS!
[]+  Done                    mysqld_safe --skip-grant-tables --skip-networking
[root@db01-sa ~]# mysql -uroot -p123
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.38 Source distribution

Copyright (c) 2000, 2017, 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.

----add end  by nod 18-06-21------