MySQL权限实战
1、GRANT命令使用说明：
先来看一个例子，创建一个只允许从本地登录的超级用户jack，并允许将权限赋予别的用户，密码为：jack.
mysql> grant all privileges on *.* to jack@'localhost' identified by "jack" with grant option; Query OK, 0 rows affected (0.01 sec)
GRANT命令说明：
ALL PRIVILEGES 是表示所有权限，你也可以使用select、update等权限。
ON 用来指定权限针对哪些库和表。
*.* 中前面的*号用来指定数据库名，后面的*号用来指定表名。
TO 表示将权限赋予某个用户。
jack@'localhost' 表示jack用户，@后面接限制的主机，可以是IP、IP段、域名以及%，%表示任何地方。注意：这里%有的版本不包括本地，以前碰到过给某个用户设置了%允许任何地方登录，但是在本地登录不了，这个和版本有关系，遇到这个问题再加一个localhost的用户就可以了。
IDENTIFIED BY 指定用户的登录密码。
WITH GRANT OPTION 这个选项表示该用户可以将自己拥有的权限授权给别人。注意：经常有人在创建操作用户的时候不指定WITH GRANT OPTION选项导致后来该用户不能使用GRANT命令创建用户或者给其它用户授权。
备注：可以使用GRANT重复给用户添加权限，权限叠加，比如你先给用户添加一个select权限，然后又给用户添加一个insert权限，那么该用户就同时拥有了select和insert权限。
2、刷新权限
使用这个命令使权限生效，尤其是你对那些权限表user、db、host等做了update或者delete更新的时候。以前遇到过使用grant后权限没有更新的情况，只要对权限做了更改就使用FLUSH PRIVILEGES命令来刷新权限。
mysql> flush privileges; Query OK, 0 rows affected (0.01 sec)
3、查看权限
查看当前用户的权限： mysql> show grants;+---------------------------------------------------------------------+| Grants for root@localhost |+---------------------------------------------------------------------+| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION || GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION |+---------------------------------------------------------------------+2 rows in set (0.00 sec) 查看某个用户的权限： mysql> show grants for 'jack'@'%';+-----------------------------------------------------------------------------------------------------+| Grants for jack@% |+-----------------------------------------------------------------------------------------------------+| GRANT USAGE ON *.* TO 'jack'@'%' IDENTIFIED BY PASSWORD '*9BCDC990E611B8D852EFAF1E3919AB6AC8C8A9F0' |+-----------------------------------------------------------------------------------------------------+1 row in set (0.00 sec)
4、回收权限
mysql> revoke delete on *.* from 'jack'@'localhost'; Query OK, 0 rows affected (0.01 sec)
5、删除用户
mysql> select host,user,password from user;+-----------+------+-------------------------------------------+| host | user | password |+-----------+------+-------------------------------------------+| localhost | root | || rhel5.4 | root | || 127.0.0.1 | root | || ::1 | root | || localhost | | || rhel5.4 | | || localhost | jack | *9BCDC990E611B8D852EFAF1E3919AB6AC8C8A9F0 |+-----------+------+-------------------------------------------+7 rows in set (0.00 sec) mysql> drop user 'jack'@'localhost'; Query OK, 0 rows affected (0.01 sec)
6、对账户重命名
mysql> rename user 'jack'@'%' to 'jim'@'%'; Query OK, 0 rows affected (0.00 sec)
7、修改密码
1、用set password命令
mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('123456');
Query OK, 0 rows affected (0.00 sec) 2、用mysqladmin [root@rhel5 ~]# mysqladmin -uroot -p123456 password 1234abcd
备注：
格式：mysqladmin -u用户名 -p旧密码 password 新密码 3、用update直接编辑user表
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 -ADatabase changed
mysql> update user set PASSWORD = PASSWORD('1234abcd') where user = 'root';
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec) 4、在丢失root密码的时候： [root@rhel5 ~]# mysqld_safe --skip-grant-tables &[1] 15953[root@rhel5 ~]# 130911 09:35:33 mysqld_safe Logging to '/mysql/mysql5.5/data/rhel5.4.err'.130911 09:35:33 mysqld_safe Starting mysqld daemon with databases from /mysql/mysql5.5/data[root@rhel5 ~]# mysql -u root
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2Server version: 5.5.22 Source distribution
Copyright (c) 2000, 2011, 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> \s--------------mysql Ver 14.14 Distrib 5.5.22, for Linux (i686) using EditLine wrapper
Connection id: 2Current database:
Current user: root@
SSL: Not in useCurrent pager: stdout
Using outfile: ''Using delimiter: ;
Server version: 5.5.22 Source distribution
Protocol version: 10Connection: Localhost via UNIX socket
Server characterset: utf8
Db characterset: utf8
Client characterset: utf8
Conn. characterset: utf8
UNIX socket: /tmp/mysql.sock
Uptime: 36 sec
Threads: 1 Questions: 5 Slow queries: 0 Opens: 23 Flush tables: 1 Open tables: 18 Queries per second avg: 0.138--------------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 -ADatabase changed
mysql> update user set password = PASSWORD('123456') where user = 'root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)