mysql用户管理及授权管理

mysql用户和权限管理
mysqld进程在启动的时候,将table,host,db,table_privs,clumn_privs,procs_privs,proxies_privs载入内存.

用户账号:
用户名+主机
用户名:16字符以内.
主机:
主机名: mytest
IP地址:172.168.1.20
网络地址:172.168.1.0/255.255.0.0
通配符:
172.168.%.%
172.168.1.2__
%.qq.com,注如果是域名,则mysql需要进行解析,如果取消解析,可以在启动mysqld服务时,增加参数--skip-name-resolve.
权限分以下几种:
1.全局级别.
2.库级别.
3.表级别
4.列级别.
5.存储过程和存储函数.

创建用户:
1.create user mytest@'%' identified by 'mytest'; //方式自动通知mysql读取授权表.
2.grant all on mysql.* to mytest@'%' identified by "mytest";
3.insert into mysql.user,该方式需要执行flush privlieges,触发mysql重新读取用户权限信息.

mysql> create database mytest;
ERROR 1044 (42000): Access denied for user 'mytest'@'localhost' to database 'mytest'(未授权前)

---------------------------------------------------------
在另外一个窗口给用户授权.
mysql> grant create on mytest.* to mytest@localhost;
Query OK, 0 rows affected (0.00 sec)
---------------------------------------------------------

mysql> create database mytest;
Query OK, 1 row affected (0.01 sec)

mysql> use mytest;
Database changed
mysql> create table mytab1(id int not null auto_increment primary key,name char(20));
Query OK, 0 rows affected (0.03 sec)

---------------------------------------------------------
在另外一个窗口给用户授权.
mysql> grant select,insert on mytest.* to mytest@localhost;
Query OK, 0 rows affected (0.00 sec)
mysql> grant alter on mytest.* to mytest@localhost;
Query OK, 0 rows affected (0.00 sec)
---------------------------------------------------------

重新登录后,即可对表执行insert与update.

mysql> alter table mytab1 add age tinyint;
ERROR 1142 (42000): ALTER command denied to user 'mytest'@'localhost' for table 'mytab1'
mysql> \r
Connection id: 22
Current database: mytest

mysql> alter table mytab1 add age tinyint;
Query OK, 3 rows affected (0.02 sec)
Records: 3 Duplicates: 0 Warnings: 0

查看授权信息:
mysql> grant all on mysql.* to mytest@'%' identified by "mytest";
Query OK, 0 rows affected (0.07 sec)

mysql> show grants for mytest@'%';
+-------------------------------------------------------------------------------------------------------+
| Grants for mytest@% |
+-------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'mytest'@'%' IDENTIFIED BY PASSWORD '*58F4612C3598D20A3C51A37D7B2643BF15806832' |
| GRANT ALL PRIVILEGES ON `mysql`.* TO 'mytest'@'%' |
+-------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

grant all on table db.mytest to mytest@'%';
grant all on function db.mytest to mytest@'%';

with_option:
GRANT OPTION
| MAX_QUERIES_PER_HOUR count //每小时最多查询次数,0表示无限制.
| MAX_UPDATES_PER_HOUR count //每小时最多更新次数,0表示无限制.
| MAX_CONNECTIONS_PER_HOUR count //每小时最多连接次数,0表示无限制.
| MAX_USER_CONNECTIONS count //最大用户同时连接数,0表示无限制.

给字段授权:
mysql> grant update(age) on mytest.mytab1 to mytest@localhost;
Query OK, 0 rows affected (0.00 sec)

授权超级用户权限:
mysql> grant super on *.* to mytest@localhost;
Query OK, 0 rows affected (0.00 sec)

收回权限:
mysql> show grants for mytest@127.0.0.1;
+---------------------------------------------------------------------------------------------------------------+
| Grants for mytest@127.0.0.1 |
+---------------------------------------------------------------------------------------------------------------+
| GRANT SUPER ON *.* TO 'mytest'@'127.0.0.1' IDENTIFIED BY PASSWORD '*58F4612C3598D20A3C51A37D7B2643BF15806832' |
| GRANT SELECT, INSERT, CREATE, ALTER ON `mytest`.* TO 'mytest'@'127.0.0.1' |
| GRANT UPDATE (age) ON `mytest`.`mytab1` TO 'mytest'@'127.0.0.1' |
+---------------------------------------------------------------------------------------------------------------+
3 rows in set (0.00 sec)

mysql> revoke select on mytest.* from mytest@127.0.0.1;
Query OK, 0 rows affected (0.00 sec)

删除用户:
drop user 用户名@主机.
重命名用户:
rename user new@主机名 to old_name@主机名;
mysql> rename user mytest@localhost to mytest@127.0.0.1;
Query OK, 0 rows affected (0.00 sec)

初始化mysql密码:
通过设置--skip-grant-tables和--skip-networking,重启mysqld服务:
[root@idc131 ~]# service mysqld stop
Shutting down MySQL... SUCCESS!
[root@idc131 ~]# mysqld_safe --skip-grant-tables --skip-networking --user=mysql &

修改所有用户密码:
mysql> update mysql.user set password=password('mysql');
Query OK, 4 rows affected (0.00 sec)
Rows matched: 4 Changed: 4 Warnings: 0

重启mysql服务:
[root@idc131 ~]# service mysqld restart
Shutting down MySQL.140803 23:09:12 mysqld_safe mysqld from pid file /usr/local/mysql/data/idc131.pid ended
SUCCESS!
Starting MySQL.. SUCCESS!
[1]+ Done mysqld_safe --skip-grant-tables --skip-networking --user=mysql
[root@idc131 ~]#
[root@idc131 ~]#
[root@idc131 ~]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.38-log MySQL Community Server (GPL)

Copyright (c) 2000, 2014, 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>

注意:此次因服务启动时,未读取授权表,故无法通过以下方式修改密码:
mysql> set password root@'localhost'=password('123');
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'root@'localhost'=password('123')' at line 1

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