mysql dba系统学习（15）mysql用户管理之二

mysql dba系统学习（15）mysql用户管理之二2014-06-25mysql用户管理

一，创建和删除用户

mysql> select current_user（）; 查询当前的登录用户

+----------------+

| current_user（） |

+----------------+

| root@localhost |

+----------------+

创建用户的时候没有分配任何权限，%表示的是任何机器，但是不包括localhost和127.0.0.1

mysql> create user "chenzhongyang"@"%" identified by "123456";

mysql> create user "chen"@"127.0.0.1" identified by "123456";

删除用户

mysql> drop user "chenzhongyang"@"%";

Query OK, 0 rows affected （0.04 sec）

[root@test4 /]# mysql -uchen -p123456 -h127.0.0.1

Welcome to the MySQL monitor. Commands end with ; or g.

Your MySQL connection id is 4

Server version: 5.1.70-log Source distribution

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（）;

+----------------+

| user（） |

+----------------+

| chen@localhost |

+----------------+

1 row in set （0.01 sec）

刚刚创建的用户的权限是usage

mysql> show grants;

+-------------------------------------------------------------------------------------------------------------+

| Grants for chen@127.0.0.1 |

+-------------------------------------------------------------------------------------------------------------+

| GRANT USAGE ON *.* TO "chen"@"127.0.0.1" IDENTIFIED BY PASSWORD "*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9" |

+-------------------------------------------------------------------------------------------------------------+

1 row in set （0.02 sec）

修改用户名，这个时候密码和权限没有变化

mysql> rename user "chen"@"127.0.0.1" to "chenzhongyang"@"127.0.0.1";

二，匿名用户

创建匿名用户之后，那么任何机器的任何用户都可以登录到mysql，所以这样很危险

mysql> insert into user（host,user,password） values（"%","",""）;

Query OK, 1 row affected, 3 warnings （0.17 sec）

mysql> flush privileges; 刷新权限将重新加载user表的内容

Query OK, 0 rows affected （0.03 sec）