13.1 設置更改root密碼

時間 2019-11-10

標籤 13.1 設置更改 root 密碼欄目 Linux 简体版

原文原文鏈接

設置更改root密碼目錄概要

/usr/local/mysql/bin/mysql -uroot
更改環境變量PATH，增長mysql絕對路徑
mysqladmin -uroot password '123456'
mysql -uroot -p123456
密碼重置
vi /etc/my.cnf//增長skip-grant
重啓mysql服務 /etc/init.d/mysqld restart
mysql -uroot
use mysql;
update user set password=password('aminglinux') where user='root';

設置更改root密碼

root用戶是mysql的超級管理員用戶，和linux系統的root用戶相似，不過和Linux的不同
默認mysql的 root 用戶密碼是空的，直接就能夠鏈接上去，不須要輸入密碼，可是不安全，因此就須要設置一個密碼
爲了方便使用mysql服務，將mysql目錄加入到環境變量裏

打開系統，查看mysql是否啓動

[root@hanfeng ~]# ps aux |grep mysql
root      1659  0.0  0.1 115392  1712 ?        S    21:29   0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/data/mysql --pid-file=/data/mysql/hanfeng.pid
mysql     2260  0.0 45.3 973548 458428 ?       Sl   21:29   0:02 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysql --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/data/mysql/hanfeng.err --pid-file=/data/mysql/hanfeng.pid
root      2386  0.0  0.0 112676   984 pts/0    R+   22:06   0:00 grep --color=auto mysql
[root@hanfeng ~]#

如果沒有啓動mysql的話，將mysql啓動起來

/etc/init.d/mysqld start

在啓動mysql後，使用mysql -uroot命令，可是mysql命令會提示不存在，由於安裝的mysql是在/usr/local/mysql/bin/mysql，而這個目錄並不在環境變量PATH裏面，因此它會報錯

[root@hanfeng ~]# mysql -uroot
-bash: mysql: 未找到命令
[root@hanfeng ~]# ls /usr/local/mysql/bin/mysql
/usr/local/mysql/bin/mysql
[root@hanfeng ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin
[root@hanfeng ~]#

若想要這個命令直接運行，須要把PATH作一個更改

[root@hanfeng ~]# export PATH=$PATH:/usr/local/mysql/bin/
[root@hanfeng ~]#

這時再來使用mysql -uroot命令就會發現可使用了

退出mysql輸入 quit 便可

[root@hanfeng ~]# mysql -uroot
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.35 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> quit
Bye
[root@hanfeng ~]#

若想要變量永久生效，還須要將export PATH=$PATH:/usr/local/mysql/bin/ 放入到 /etc/profile

[root@hanfeng ~]# vim /etc/profile

將內容放到配置文件的最後面，使命令永久生效
export PATH=$PATH:/usr/local/mysql/bin/

保存退出

假設如果沒有運行 export PATH=$PATH:/usr/local/mysql/bin/ 命令，那也不能運行mysql，由於變量尚未生效，想要這個變量生效，在配置文件中加入命令後，還須要執行source /etc/profile 命令，從新加載

[root@hanfeng ~]# source /etc/profile
[root@hanfeng ~]#

通常是使用mysql -uroot -p命令

-p，表示指定密碼

密碼爲空的時候，直接回車就可進入到mysql，並能夠在其中操做一些mysql的一些行爲

[root@hanfeng ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.35 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> quit
Bye
[root@hanfeng ~]#

退出mysql，輸入 quit 便可
設置mysql密碼，命令爲mysqladmin -uroot passwd 'hanfeng.1' 在 ' ' 爲密碼

[root@hanfeng ~]# mysqladmin -uroot password 'hanfeng.1'
Warning: Using a password on the command line interface can be insecure.
[root@hanfeng ~]#

在設置密碼的時候，會看到有輸出信息，但這不是報錯信息，這是告訴你你如今密碼在當前命令行顯示出來了，這樣不太安全
這時在想直接登陸mysql，就會提示須要輸入密碼了

[root@hanfeng ~]# mysql -uroot
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
[root@hanfeng ~]#

在使用-p，並輸入密碼就能夠正常的進入到mysql命令行了

[root@hanfeng ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 5.6.35 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> quit
Bye
[root@hanfeng ~]#

知道mysql的root密碼，去更改密碼

如果這時知道mysql密碼，去修改mysql密碼，看到輸出的提示信息不用去理會

格式
- mysqladmin -uroot -p'hanfeng.1' password 'hanfeng'

[root@hanfeng ~]# mysqladmin -uroot -p'hanfeng.1' password 'hanfeng'
Warning: Using a password on the command line interface can be insecure.
[root@hanfeng ~]#

指定新密碼去登陸，固然也能夠不明文指定密碼，知道-p回車，輸入密碼登陸也行

[root@hanfeng ~]# mysql -uroot -p 'hanfeng'
Enter password: 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
[root@hanfeng ~]# mysql -uroot -p'hanfeng'
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 13
Server version: 5.6.35 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> quit
Bye
[root@hanfeng ~]#

在明文指定密碼的時候，密碼能夠加單引號，也能夠不加單引號，建議加上單引號，防止密碼有特殊符號的存在——>（如果不加單引號，而密碼中又有特殊符號，就有可能會不識別）

不知道mysql的root密碼，去更改密碼

在不知道mysql的root用戶密碼的時候，先去更改 /etc/my.cnf 下配置文件中加入skip-grant

skip-grant ，表示忽略受權，也就是說操做mysql的時候不須要用戶名和密碼了，能直接登陸

[root@hanfeng ~]# vim /etc/my.cnf

在[mysqld]下面
加入一行
skip-grant

保存退出

在更改配置文件後，重啓mysql服務

[root@hanfeng ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL.. SUCCESS! 
[root@hanfeng ~]#

這時候在輸入mysql -uroot ，會發現直接進入mysql，而不須要密碼了

[root@hanfeng ~]# mysql -uroot
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.35 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>

在登陸進mysql後，還須要更改一個表，由於用戶名和密碼是存在於一個mysql庫裏面的，使用 use mysql; 切換庫，在切換到mysql庫裏面，而後去更改一個存用戶名密碼的user表

use mysql; 切換庫

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>

查看user表，輸入select * from user; 命令，會看到輸出亂七八糟的亂碼，裏面存放的就是用戶名和密碼，還有權限和受權等信息

mysql> select * from user;
+-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+-----------------------+-----------------------+------------------+
| Host      | User | Password                                  | 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 | 

等等等，都是亂碼

查看password表，會看到密碼都是加密的

mysql> select password from user where user=’root’;
ERROR 1054 (42S22): Unknown column '’root’' in 'where clause'
mysql> select password from user where user='root';
+-------------------------------------------+
| password                                  |
+-------------------------------------------+
| *406D1994F8340A1442C5090388944CCB985BA3DE |
|                                           |
|                                           |
|                                           |
+-------------------------------------------+
4 rows in set (0.00 sec)

mysql>

更改user表，使用update user set password=password('aminglinux') where user='root'; 命令

update user set password=password('aminglinux') where user='root';

密碼字段       函數 //用於加密密碼    高亮部分：爲條件語句

mysql> update user set password=password('aminglinux') where user='root';
Query OK, 4 rows affected (0.00 sec)
Rows matched: 4  Changed: 4  Warnings: 0

mysql>

提示說4行修改完畢，即便有些行是空的
這樣密碼就更改爲功了，輸入quit退出數據庫便可

mysql> quit
Bye

再去 /etc/my.cnf 配置文件中刪除免受權配置，即刪除skip-grant——>如果不刪除，那麼以後全部的用戶都不須要輸入密碼，就能夠登陸進去，這樣安全性過低

[root@hanfeng ~]# vim /etc/my.cnf

在[mysqld]下面刪除剛添加的
刪除skip-grant

保存退出

重啓mysql服務

[root@hanfeng ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL.. SUCCESS! 
[root@hanfeng ~]#

重啓完以後，再用新的密碼測試下，會看到新的密碼能夠登陸

[root@hanfeng ~]# mysql -uroot -paminglinux
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: 5.6.35 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> quit
Bye
[root@hanfeng ~]#