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MySQL 用户权限详细汇总

黄舟
黄舟Original
2017-02-16 11:54:131791browse

1,MySQL权限体系

mysql 的权限体系大致分为5个层级:
全局层级:
全局权限适用于一个给定服务器中的所有数据库。这些权限存储在mysql.user表中。GRANT ALL ON .和REVOKE ALL ON .只授予和撤销全局权限。
数据库层级:
数据库权限适用于一个给定数据库中的所有目标。这些权限存储在mysql.db表中。GRANT ALL ON db_name.和REVOKE ALL ON db_name.只授予和撤销数据库权限。
表层级:
表权限适用于一个给定表中的所有列。这些权限存储在mysql.talbes_priv表中。GRANT ALL ON db_name.tbl_name和REVOKE ALL ON db_name.tbl_name只授予和撤销表权限。
列层级:
列权限适用于一个给定表中的单一列。这些权限存储在mysql.columns_priv表中。当使用REVOKE时,您必须指定与被授权列相同的列。
子程序层级:
CREATE ROUTINE, ALTER ROUTINE, EXECUTE和GRANT权限适用于已存储的子程序。这些权限可以被授予为全局层级和数据库层级。而且,除了CREATE ROUTINE外,这些权限可以被授予为子程序层级,并存储在mysql.procs_priv表中。

这些权限信息存储在下面的系统表中:
mysql.user
mysql.db
mysql.host
mysql.table_priv
mysql.column_priv
mysql. procs_priv
当用户连接进来,mysqld会通过上面的这些表对用户权限进行验证!

2, 千里追踪之5表

相对于oracle来说,mysql的特性是可以限制ip,用户user、ip地址host、密码passwd这3个是用户管理的基础,权限的细节基本在mysql.user、mysql.db、mysql.host、mysql.table_priv、mysql.column_priv这几张表就可以看到很多细节,接下来仔细分析这些表就可以知道权限的奥秘。


5121c5d8c817ad4c086d9118458eb6a9
原博客地址:    http://www.php.cn/
原作者:黄杉 (mchdba)


演示过程中需要建立用户来演示,先简单介绍下如何创建用户:
GRANT priv_type ON database.table
TO user[IDENTIFIED BY [PASSWORD] ‘password’]
[,user [IDENTIFIED BY [PASSWORD] ‘password’]…]

示例:
GRANT SELECT, INSERT, UPDATE, DELETE ON d3307.* TO zengxiaoteng@’%’ IDENTIFIED BY ‘0523’;

2.1db表

2.1.1 表结构如下:

mysql> desc mysql.db;
+-----------------------+---------------+------+-----+---------+-------+
| Field                 | Type          | Null | Key | Default | Extra |
+-----------------------+---------------+------+-----+---------+-------+
| Host                  | char(60)      | NO   | PRI |         |       |
| Db                    | char(64)      | NO   | PRI |         |       |
| User                  | char(16)      | NO   | PRI |         |       |
| Select_priv           | enum('N','Y') | NO   |     | N       |       |
| Insert_priv           | enum('N','Y') | NO   |     | N       |       |
| Update_priv           | enum('N','Y') | NO   |     | N       |       |
| Delete_priv           | enum('N','Y') | NO   |     | N       |       |
| Create_priv           | enum('N','Y') | NO   |     | N       |       |
| Drop_priv             | enum('N','Y') | NO   |     | N       |       |
| Grant_priv            | enum('N','Y') | NO   |     | N       |       |
| References_priv       | enum('N','Y') | NO   |     | N       |       |
| Index_priv            | enum('N','Y') | NO   |     | N       |       |
| Alter_priv            | enum('N','Y') | NO   |     | N       |       |
| Create_tmp_table_priv | enum('N','Y') | NO   |     | N       |       |
| Lock_tables_priv      | enum('N','Y') | NO   |     | N       |       |
| Create_view_priv      | enum('N','Y') | NO   |     | N       |       |
| Show_view_priv        | enum('N','Y') | NO   |     | N       |       |
| Create_routine_priv   | enum('N','Y') | NO   |     | N       |       |
| Alter_routine_priv    | enum('N','Y') | NO   |     | N       |       |
| Execute_priv          | enum('N','Y') | NO   |     | N       |       |
| Event_priv            | enum('N','Y') | NO   |     | N       |       |
| Trigger_priv          | enum('N','Y') | NO   |     | N       |       |
+-----------------------+---------------+------+-----+---------+-------+22 rows in set (0.02 sec)

mysql>

2.1.2分析如下:

db表存储了所有对一个数据库的所有操作权限。创建用户的时候,都会往Host字段,User字段,Password字段录入用户信息;
而当执行 GRANT SELECT,INSERT ON d3307.* TO u4@’%’ IDENTIFIED BY ‘u40523’;类似的授权语句的话,Select_priv和Insert_priv字段的值会变成Y其它字段仍然是N;
当你执行了GRANT ALL ON d3307.* TO u4@’%’ IDENTIFIED BY ‘u40523’;类似的复制语句的话,后面的字段都会变成Y的值;

2.1.3 创建单个select、insert授予权限

创建用户:

GRANT SELECT,INSERT ON d3307.* TO user4@'192.168.52' IDENTIFIED BY 'user0523';

应该除了Host、db、user字段有值,除了Select_priv、Insert_priv值为Y外,其它的都是N。

查看mysql.db表的记录正是如此,如下所示:

mysql> SELECT * FROM mysql.`db` where user='user4'\G;
*************************** 1. row ***************************
                 Host: 192.168.52
                   Db: d3307
                 User: user4
          Select_priv: Y
          Insert_priv: Y
          Update_priv: N
          Delete_priv: N
          Create_priv: N
            Drop_priv: N
           Grant_priv: N
      References_priv: N
           Index_priv: N
           Alter_priv: NCreate_tmp_table_priv: N
     Lock_tables_priv: N
     Create_view_priv: N
       Show_view_priv: N
  Create_routine_priv: N
   Alter_routine_priv: N
         Execute_priv: N
           Event_priv: N
         Trigger_priv: N1 row in set (0.01 sec)

ERROR: 
No query specified

mysql>

2.1.4 授予ALL权限

执行sql语句建立用户:

GRANT ALL ON d3307.* TO dba5@'192.168.52.1' IDENTIFIED BY 'dba0523';

建立用户的时候,如下所示,除了Host、db、user字段外,所有的*_priv字段记录都会变成Y值,(Grant_priv仍然是N值除非加了WITH* GRANT OPTION执行GRANT ALL ON d3307.* TO dba5@’192.168.52.1’ IDENTIFIED BY ‘dba0523’ WITH GRANT OPTION ;)

如下所示:

mysql> SELECT * FROM mysql.`db` where user='dba5'\G;*************************** 1. row ***************************                 Host: 192.168.52.1                   Db: d3307                 User: dba5          Select_priv: Y          Insert_priv: Y          Update_priv: Y          Delete_priv: Y          Create_priv: Y            Drop_priv: Y           Grant_priv: N      References_priv: Y           Index_priv: Y           Alter_priv: YCreate_tmp_table_priv: Y     Lock_tables_priv: Y     Create_view_priv: Y       Show_view_priv: Y
  Create_routine_priv: Y
   Alter_routine_priv: Y         Execute_priv: Y           Event_priv: Y         Trigger_priv: Y1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>

2.2 user表

2.2.1 表结构:

mysql> desc mysql.user;
    +------------------------+-----------------------------------+------+-----+---------+-------+
    | Field                  | Type                              | Null | Key | Default | Extra |
    +------------------------+-----------------------------------+------+-----+---------+-------+
    | Host                   | char(60)                          | NO   | PRI |         |       |
    | User                   | char(16)                          | NO   | PRI |         |       |
    | Password               | char(41)                          | NO   |     |         |       |
    | Select_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Insert_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Update_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Delete_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Create_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Drop_priv              | enum('N','Y')                     | NO   |     | N       |       |
    | Reload_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Shutdown_priv          | enum('N','Y')                     | NO   |     | N       |       |
    | Process_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | File_priv              | enum('N','Y')                     | NO   |     | N       |       |
    | Grant_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | References_priv        | enum('N','Y')                     | NO   |     | N       |       |
    | Index_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Alter_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Show_db_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | Super_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Create_tmp_table_priv  | enum('N','Y')                     | NO   |     | N       |       |
    | Lock_tables_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Execute_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | Repl_slave_priv        | enum('N','Y')                     | NO   |     | N       |       |
    | Repl_client_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Create_view_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Show_view_priv         | enum('N','Y')                     | NO   |     | N       |       |
    | Create_routine_priv    | enum('N','Y')                     | NO   |     | N       |       |
    | Alter_routine_priv     | enum('N','Y')                     | NO   |     | N       |       |
    | Create_user_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Event_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Trigger_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | Create_tablespace_priv | enum('N','Y')                     | NO   |     | N       |       |
    | ssl_type               | enum('','ANY','X509','SPECIFIED') | NO   |     |         |       |
    | ssl_cipher             | blob                              | NO   |     | NULL    |       |
    | x509_issuer            | blob                              | NO   |     | NULL    |       |
    | x509_subject           | blob                              | NO   |     | NULL    |       |
    | max_questions          | int(11) unsigned                  | NO   |     | 0       |       |
    | max_updates            | int(11) unsigned                  | NO   |     | 0       |       |
    | max_connections        | int(11) unsigned                  | NO   |     | 0       |       |
    | max_user_connections   | int(11) unsigned                  | NO   |     | 0       |       |
    | plugin                 | char(64)                          | YES  |     |         |       |
    | authentication_string  | text                              | YES  |     | NULL    |       |
    | password_expired       | enum('N','Y')                     | NO   |     | N       |       |
    +------------------------+-----------------------------------+------+-----+---------+-------+
    43 rows in set (0.10 sec)

mysql>

2.2.2 分析

存储用户记录的表,存储了用户的信息,每一次创建用户的时候,都会往这个表里录入记录,当你执行了,都会往Host字段,User字段,Password字段录入数据,但是后面的Select_priv、Insert_priv、Update_priv等字段的值,只有赋予GRANT ALL ON . TO timdba@’192.%’ IDENTIFIED BY ‘timdba0523’;类似的对所有库的操作权限的时候才会被记录成Y,否则都记录成N。

2.2.3 创建对库所有表有操作权限的普通用户

创建用户:

GRANT SELECT,UPDATE ON d3307.* TO user6@'192.168.52.1' IDENTIFIED BY 'user0523';

分析结果:存储在mysql.user表里面的记录当中,Host、User、Password是有值的,但是其它的Select_priv等*_priv字段值都是N。

验证结果,去查看表里的存储记录,如下所示

mysql> SELECT * FROM mysql.user where user='user6'\G;
*************************** 1. row ***************************
                  Host: 192.168.52.1
                  User: user6
              Password: *A4D1F6ACEBC5D3EB0F6D33C7DCC629E8BE55B75A
           Select_priv: N
           Insert_priv: N
           Update_priv: N
           Delete_priv: N
           Create_priv: N
             Drop_priv: N
           Reload_priv: N
         Shutdown_priv: N
          Process_priv: N
             File_priv: N
            Grant_priv: N
       References_priv: N
            Index_priv: N
            Alter_priv: N
          Show_db_priv: N
            Super_priv: N
 Create_tmp_table_priv: N
      Lock_tables_priv: N
          Execute_priv: N
       Repl_slave_priv: N
      Repl_client_priv: N
      Create_view_priv: N
        Show_view_priv: N
   Create_routine_priv: N
    Alter_routine_priv: N
      Create_user_priv: N
            Event_priv: N
          Trigger_priv: NCreate_tablespace_priv: N
              ssl_type: 
            ssl_cipher: 
           x509_issuer: 
          x509_subject: 
         max_questions: 0
           max_updates: 0
       max_connections: 0
  max_user_connections: 0
                plugin: mysql_native_password
 authentication_string: 
      password_expired: N1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>

2.2.4 创建对于所有表有操作权限的用户

创建用户:

mysql> GRANT SELECT,UPDATE ON *.* TO user7@'%' IDENTIFIED BY 'user0523';
Query OK, 0 rows affected (0.00 sec)

mysql>

分析:
基本的Host、User、Password字段有记录值,然后grant了select和update所以关于*_priv字段中select和update字段有值为Y,其它*_priv字段值应该是N。

查看记录结果,分享正确,如下所示:

mysql> SELECT * FROM mysql.user where user='user7'\G;
*************************** 1. row ***************************
                  Host: %
                  User: user7
              Password: *A4D1F6ACEBC5D3EB0F6D33C7DCC629E8BE55B75A
           Select_priv: Y
           Insert_priv: N
           Update_priv: Y
           Delete_priv: N
           Create_priv: N
             Drop_priv: N
           Reload_priv: N
         Shutdown_priv: N
          Process_priv: N
             File_priv: N
            Grant_priv: N
       References_priv: N
            Index_priv: N
            Alter_priv: N
          Show_db_priv: N
            Super_priv: N
 Create_tmp_table_priv: N
      Lock_tables_priv: N
          Execute_priv: N
       Repl_slave_priv: N
      Repl_client_priv: N
      Create_view_priv: N
        Show_view_priv: N
   Create_routine_priv: N
    Alter_routine_priv: N
      Create_user_priv: N
            Event_priv: N
          Trigger_priv: NCreate_tablespace_priv: N
              ssl_type: 
            ssl_cipher: 
           x509_issuer: 
          x509_subject: 
         max_questions: 0
           max_updates: 0
       max_connections: 0
  max_user_connections: 0
                plugin: mysql_native_password
 authentication_string: 
      password_expired: N1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>

2.3 tables_priv表

2.3.1 查看表结构

mysql> desc mysql.tables_priv;
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
| Field       | Type                                                                                                                              | Null | Key | Default           | Extra                       |
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
| Host        | char(60)                                                                                                                          | NO   | PRI |                   |                             |
| Db          | char(64)                                                                                                                          | NO   | PRI |                   |                             |
| User        | char(16)                                                                                                                          | NO   | PRI |                   |                             |
| Table_name  | char(64)                                                                                                                          | NO   | PRI |                   |                             |
| Grantor     | char(77)                                                                                                                          | NO   | MUL |                   |                             |
| Timestamp   | timestamp                                                                                                                         | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| Table_priv  | set('Select','Insert','Update','Delete','Create','Drop','Grant','References','Index','Alter','Create View','Show view','Trigger') | NO   |     |                   |                             |
| Column_priv | set('Select','Insert','Update','References')                                                                                      | NO   |     |                   |                             |
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
8 rows in set (0.00 sec)

mysql>

2.3.2 分析:

记录了对一个表的单独授权记录,只有执行grant insert on dbname.tablename to user1@’%’identified by ‘pwd’;类似的授权记录才会在这个表里录入授权信息;其中各个字段涵义如下:

字段 存储的数据
Host字段 用户的登录ip范围
User字段 表所在的数据库名称
Table_name字段 授权的表的名称
Grantor字段 执行grant建立用户的授权者
Timestamp字段 0000-00-00 00:00:00
Table_priv字段 所授予的操作表的权限,比如select、udate、delete等
Column_priv字段 对这个表的某个字段单独授予的权限



另外当赋予all在某张表上的时候,Table_priv列会多处所有关于表的授权记录,描述如下
Select,Insert,Update,Delete,Create,Drop,References,Index,Alter,Create View,Show view,Trigger。

2.3.3 创建单独操作这个表的用户

创建用户:

mysql> GRANT INSERT,SELECT,UPDATE ON d3307.t TO user8@'192.168.52.1' IDENTIFIED BY 'dba0523';
Query OK, 0 rows affected (0.00 sec)

mysql>

分析结果:
应该是Host、Db、User、Table_name、Grantor、Timestamp、Table_priv是有值的,但是Column_priv没有值,因为没有单独对某一个列做了授权限制的。

查看权限,如下所示:

mysql> SELECT * FROM mysql.tables_priv where user='user8'\G;*************************** 1. row ***************************       Host: 192.168.52.1         Db: d3307       User: user8
 Table_name: t    Grantor: root@localhost
  Timestamp: 0000-00-00 00:00:00
 Table_priv: Select,Insert,Update
Column_priv: 
1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>


2.3.4 单独为某个列授权

授权语句操作:

mysql> GRANT UPDATE(created_time) ON d3307.t  TO user8@'192.168.52.1';
Query OK, 0 rows affected (0.00 sec)

mysql> GRANT SELECT(uname)  ON d3307.t  TO user8@'192.168.52.1';
Query OK, 0 rows affected (0.00 sec)

mysql>

分析:
单独为某个列授权,会记录在这个表的Column_priv字段里面,会记录下对单个列的授权操作记录

查看记录:

mysql> SELECT * FROM mysql.tables_priv where user='user8'\G;*************************** 1. row ***************************       Host: 192.168.52.1         Db: d3307       User: user8
 Table_name: t    Grantor: root@localhost
  Timestamp: 0000-00-00 00:00:00
 Table_priv: Select,Insert,Update
Column_priv: Select,Update
1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>


而且还会在另外一个权限表mysql.columns_priv留下记录单独的授权记录,如下所示:

mysql> SELECT * FROM mysql.columns_priv WHERE USER='user8';
+--------------+-------+-------+------------+--------------+---------------------+-------------+| Host         | Db    | User  | Table_name | Column_name  | Timestamp           | Column_priv |
+--------------+-------+-------+------------+--------------+---------------------+-------------+| 192.168.52.1 | d3307 | user8 | t          | created_time | 0000-00-00 00:00:00 | Update      |
| 192.168.52.1 | d3307 | user8 | t          | uname        | 0000-00-00 00:00:00 | Select      |
+--------------+-------+-------+------------+--------------+---------------------+-------------+
2 rows in set (0.00 sec)mysql>


2.4 columns_priv表

2.4.1 表结构如下:

mysql> desc mysql.columns_priv;
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
| Field       | Type                                         | Null | Key | Default           | Extra                       |
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
| Host        | char(60)                                     | NO   | PRI |                   |                             |
| Db          | char(64)                                     | NO   | PRI |                   |                             |
| User        | char(16)                                     | NO   | PRI |                   |                             |
| Table_name  | char(64)                                     | NO   | PRI |                   |                             |
| Column_name | char(64)                                     | NO   | PRI |                   |                             |
| Timestamp   | timestamp                                    | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| Column_priv | set('Select','Insert','Update','References') | NO   |     |                   |                             |
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
7 rows in set (0.04 sec)

mysql>


2.4.2 分析

单独对某一列有操作权限的时候,会将权限信息记录在这个表里面,比如新建立一个账号GRANT UPDATE(uname) ON d3307.t TO user9@’192.168.52.%’ IDENTIFIED BY ‘user0520’; 那么就会在这个表上录入授权信息记录,重点看Column_name字段和Column_priv字段的值。

2.4.3 实际操作

创建用户操作:

mysql> GRANT UPDATE(uname) ON d3307.t TO user9@'192.168.52.%' IDENTIFIED BY 'user0520';
Query OK, 0 rows affected (0.00 sec)

mysql>

查看结果,会在这个columns_priv表留下一条记录:

mysql> SELECT * FROM mysql.columns_priv WHERE USER='user9';
        +--------------+-------+-------+------------+-------------+---------------------+-------------+
        | Host         | Db    | User  | Table_name | Column_name | Timestamp           | Column_priv |
        +--------------+-------+-------+------------+-------------+---------------------+-------------+
        | 192.168.52.% | d3307 | user9 | t          | uname       | 0000-00-00 00:00:00 | Update      |
        +--------------+-------+-------+------------+-------------+---------------------+-------------+        1 row in set (0.00 sec)

        mysql>


2.5 procs_priv表

2.5.1 表结构

mysql> desc proxies_priv;
+--------------+------------+------+-----+-------------------+-----------------------------+| Field        | Type       | Null | Key | Default           | Extra                       |
+--------------+------------+------+-----+-------------------+-----------------------------+| Host         | char(60)   | NO   | PRI |                   |                             |
| User         | char(16)   | NO   | PRI |                   |                             |
| Proxied_host | char(60)   | NO   | PRI |                   |                             |
| Proxied_user | char(16)   | NO   | PRI |                   |                             |
| With_grant   | tinyint(1) | NO   |     | 0                 |                             |
| Grantor      | char(77)   | NO   | MUL |                   |                             |
| Timestamp    | timestamp  | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+--------------+------------+------+-----+-------------------+-----------------------------+
7 rows in set (0.04 sec)mysql>


2.6.2分析:

procs_priv表可以对存储过程和存储函数进行权限设置。主要字段:proc_priv。


3,创建用户

3.1、CREATE USER创建用户

使用CREATE USER语句创建用户,必须要拥有CREATE USER权限。其格式如下:

CREATE USER user[IDENTIFIED BY [PASSWORD] 'password'],
[user[IDENTIFIED BY [PASSWORD] 'password']]...

  其中,user参数表示新建用户的账户,user由用户名(User)和主机名(Host)构成;IDENTIFIED BY关键字用来设置用户的密码;password参数表示用户的密码;如果密码是一个普通的字符串,就不需要使用PASSWORD关键字。可以没有初始密码。

例如

CREATE USER 'sys'@'%' IDENTIFIED BY 'sys';

执行之后user表会增加一行记录,但权限暂时全部为‘N’。

3.2、用INSERT语句新建普通用户

可以使用INSERT语句直接将用户的信息添加到mysql.user表。但必须拥有mysql.user表的INSERT权限。

另外,ssl_cipher、x509_issuer、x509_subject等必须要设置值,否则INSERT语句无法执行。

示例:
INSERT INTO mysql.user(Host,User,Password,ssl_cipher,x509_issuer,x509_subject) VALUES(‘%’,’newuser1’,PASSWORD(‘123456’),”,”,”)
执行INSERT之后,要使用命令:FLUSH PRIVILEGES;命令来使用户生效。


3.3、用GRANT语句来新建普通用户

  用GRANT来创建新的用户时,能够在创建用户时为用户授权。但需要拥有GRANT权限。

  语法如下:

GRANT priv_type ON database.table
TO user[IDENTIFIED BY [PASSWORD] 'password']
[,user [IDENTIFIED BY [PASSWORD] 'password']...]

priv_type:参数表示新yoghurt的权限;
databse.table:参数表示新用户的权限范围;
user:参数新用户的账户,由用户名和主机构成;
IDENTIFIED BY关键字用来设置密码;
password:新用户密码;
PS:GRANT语句可以同时创建多个用户。.与db.*的区别在于。.对所有数据库生效,所以user表的SELECT会变为Y。而db.*user表为’N’,更改的是Db表。


4,删除用户

4.1 drop user删除用户

DROP USER语句删除普通用户,需要拥有DROP USER权限。
语法如下:

DROP USER user[,user]...

user是需要删除的用户,由用户名(User)和主机名(Host)构成。


4.2 DELETE语句删除普通用户

可以使用DELETE语句直接将用户的信息从mysql.user表中删除。但必须拥有对mysql.user表的DELETE权限。DELETE FROM mysql.user WHERE Host = ‘%’ AND User = ‘admin’; 删除完成后,一样要FLUSH PRIVILEGES才生效。


5,修改用户密码

5.1 使用mysqladmin命令来修改root用户的密码

语法:

mysqladmin -u -username -p password "new_password" 

新密码(new_password)必须用括号括起来,单引号会报错。

示例,修改中要输入旧的密码来验证:

[root@data02 ~]# mysqladmin -u timman -p password "tim" --socket=/usr/local/mysql3307/mysql.sock
Enter password: 
[root@data02 ~]#
[root@data02 ~]# mysql --socket=/usr/local/mysql3307/mysql.sock -utimman -ptim -e "select @@port";+--------+| @@port |
+--------+|   3307 |
+--------+[root@data02 ~]#


5.2 修改user表

UPDATE user表的passwor字段的值,也可以达到修改密码的目的;

UPDATE user SET Password = PASSWORD('123') WHERE USER = 'myuser';FLUSH PRIVILEGES;

刷新后生效。


5.3 使用SET语句来修改密码

使用root用户登录到MySQL服务器后,可以使用SET语句来修改密码:
修改自己的密码,不需要用户名

SET PASSWORD = PASSWORD("123");

修改其他用户密码:

SET PASSWORD FOR 'myuser'@'%'=PASSWORD("123456") FOR 用户名@主机名


5.4 GRANT语句来修改普通用户的密码

使用GRANT语句修改普通用户的密码,必须拥有GRANT权限。

GRANT priv_type ON database.table TO user [IDENTIFIED BY [PASSWORD] 'password']

示例:

GRANT SELECT ON *.* TO 'user10'@'%' IDENTIFIED BY '123'


5.5 忘记用户密码的解决办法

普通用户,直接用root超级管理员登录进去修改密码就可以了,但是如果root密码丢失了,怎么办呢?

5.5.1 msyqld_saft方式找回密码

停止mysql:service mysqld stop;
    安全模式启动:mysqld_safe –skip-grant-tables &
   无密码回车键登录:mysql -uroot –p
   重置密码:use mysql; update user set password=password(“”) where user=’root’ and host=’localhost’; flush privileges;
   正常启动:service mysql restart
   再使用mysqladmin: mysqladmin  password ‘123456’  

5.5.2  使用普通账号来找回密码

–>(1):有一个修改test库的用户:grant create,delete,update,insert,select on d3307.* to test@’%’ identified by ‘t1’;

–>(2):复制user表文件到test库下并且赋予mysql用户访问权限:  
   cp /home/data/mysql/data/mysql/user.* /home/data/mysql/data/test/;chown mysql.mysql /home/data/mysql/data/test/user.*

–>(3):mysql -utest -pt1登录修改root密码:

–>(4):将test库的user表文件覆盖 mysql库的user表文件  
   cp /home/data/mysql/data/mysql/user.* /tmp/; mv /home/data/mysql/data/test/user.* /home/data/mysql/data/mysql/ ;    chown mysql.mysql /home/data/mysql/data/mysql/user.*;

–>(5):查找mysql进程号,并且发送SIGHUP信号,重新加载权限表。  
pgrep -n mysql; kill -SIGHUP 12234;

–>(6):无密码登录,再使用mysqladmin重新设置密码。

PS:请参考第20课的视频,那里有详细的记录整个过修改密码的过程。


6,收回用户权限

查看权限:

SHOW GRANTS;  SHOW GRANTS FOR user10@'%';

或者直接执行sql命令去mysql数据库下的user表中查看存储着用户的基本权限:

SELECT * FROM mysql.user WHERE USER='user10' AND HOST='%';

使用revoke关键字来收回权限:

REVOKE priv_type[(column_list)]ON database.tableFROM user[,user]

示例:

REVOKE EXECUTE ON d3307.* FROM user10@'%';


7,数据库用户划分

7.1 普通数据管理用户:

赋予对业务表的查询维护权限即可,授权sql如下:

GRANT SELECT, INSERT, UPDATE, DELETE ON d3307.* TO zengxiaoteng@'%' IDENTIFIED BY '0523';


7.2 开发人员账户:

赋予增删改查的权限,授权sql如下:

GRANT SELECT,INSERT,DELETE,UPDATE ON d3307.* TO huyan@'%' IDENTIFIED BY '0523';

授予创建、修改、删除 MySQL 数据表结构权限。

GRANT CREATE ON d3307.*  TO huyan@’192.168.52.11’;GRANT ALTER  ON d3307.* TO huyan@’192.168.52.11’;GRANT DROP   ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 外键权限:

GRANT REFERENCES ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 临时表权限:

GRANT CREATE TEMPORARY TABLES ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 索引权限:

GRANT INDEX ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 视图、查看视图源代码 权限:

GRANT CREATE VIEW ON d3307.* TO huyan@’192.168.52.11’;GRANT SHOW   VIEW ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 存储过程、函数 权限:

GRANT CREATE ROUTINE ON d3307.* TO huyan@’192.168.52.11’;GRANT ALTER ROUTINE ON d3307.* TO huyan@’192.168.52.11’;GRANT EXECUTE        ON d3307.* TO huyan@’192.168.52.11’;


7.3 DBA人员账户

授予普通DBA管理某个MySQL数据库(test)的权限:

GRANT ALL PRIVILEGES ON test TO sysdba@'192.168.52.%';

授予高级 DBA 管理 MySQL 中所有数据库的权限:

GRANT ALL ON *.* TO sysdba@'192.168.52.%';


7.4 数据分析人员只读账号

只需要分配只读的权限:

GRANT SELECT ON d3307.* TO dataquery@'192.168.52.129' IDENTIFIED BY '20150523';

甚至有些用户,可以只分配读取某些表列的权限,如下所示:

GRANT SELECT ON test.* TO dataquery@’192.168.52.%’ IDENTIFIED BY ‘20150523’;
GRANT SELECT(id,uname) ON d3307.t TO dataquery@’192.168.52.%’ ;

示列权限登录操作:

[root@data02 ~]# mysql --socket=/usr/local/mysql3307/mysql.sock -u dataquery -p20150523 -h192.168.52.130 -P3307Welcome TO the MySQL monitor.  Commands END WITH ; OR \g.
Your MySQL CONNECTION id IS 18SERVER VERSION: 5.6.12-LOG Source distribution

Copyright (c) 2000, 2013, 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 * FROM d3307.t;
ERROR 1142 (42000): SELECT command denied TO USER 'dataquery'@'data02' FOR TABLE 't'
mysql>
mysql> SELECT id,uname FROM d3307.t;
+----+-------+| id | uname |
+----+-------+|  1 | a     |
+----+-------+1 ROW IN SET (0.00 sec)

mysql>


8,权限划分一般原则

数据库一般划分为线上库,测试库,开发库。

8.1对于线上库:

DBA:有所有权限,超级管理员权限
应用程序:分配insert、delete、update、select、execute、events、jobs权限。
测试人员:select某些业务表权限  
开发人员:select某些业务表权限
原则:所有对线上表的操作,除了应用程序之外,都必须经由DBA来决定是否执行、已经什么时候执行等。

8.2 测试库

DBA:所有权限。  
测试人员:有insert、delete、update、select、execute、jobs权限。
数据分析人员:只有select查询权限
开发人员:有select权限。

原则:DBA有所有权限,而且严格控制表结构的变更,不允许除了dba之外的人对测试环境的库环境进行修改,以免影响测试人员测试。所有对测试库的表结构进行的修改必须由测试人员和DBA一起审核过后才能操作。

8.3 开发库

DBA:所有权限
测试人员:有库表结构以及数据的所有操作权限。
开发人员:有库表结构以及数据的所有操作权限。
数据分析人员:有库表结构以及数据的所有操作权限。
这里大家可以愉快的玩耍了,只要不mysql服务不hang不downtime都OK了。


参考文章资料:
http://www.php.cn/
http://www.php.cn/
http://www.php.cn/
http://www.php.cn/

1,MySQL权限体系

mysql 的权限体系大致分为5个层级:
全局层级:
全局权限适用于一个给定服务器中的所有数据库。这些权限存储在mysql.user表中。GRANT ALL ON .和REVOKE ALL ON .只授予和撤销全局权限。
数据库层级:
数据库权限适用于一个给定数据库中的所有目标。这些权限存储在mysql.db表中。GRANT ALL ON db_name.和REVOKE ALL ON db_name.只授予和撤销数据库权限。
表层级:
表权限适用于一个给定表中的所有列。这些权限存储在mysql.talbes_priv表中。GRANT ALL ON db_name.tbl_name和REVOKE ALL ON db_name.tbl_name只授予和撤销表权限。
列层级:
列权限适用于一个给定表中的单一列。这些权限存储在mysql.columns_priv表中。当使用REVOKE时,您必须指定与被授权列相同的列。
子程序层级:
CREATE ROUTINE, ALTER ROUTINE, EXECUTE和GRANT权限适用于已存储的子程序。这些权限可以被授予为全局层级和数据库层级。而且,除了CREATE ROUTINE外,这些权限可以被授予为子程序层级,并存储在mysql.procs_priv表中。

这些权限信息存储在下面的系统表中:
mysql.user
mysql.db
mysql.host
mysql.table_priv
mysql.column_priv
mysql. procs_priv
当用户连接进来,mysqld会通过上面的这些表对用户权限进行验证!

2, 千里追踪之5表

相对于oracle来说,mysql的特性是可以限制ip,用户user、ip地址host、密码passwd这3个是用户管理的基础,权限的细节基本在mysql.user、mysql.db、mysql.host、mysql.table_priv、mysql.column_priv这几张表就可以看到很多细节,接下来仔细分析这些表就可以知道权限的奥秘。


5121c5d8c817ad4c086d9118458eb6a9
原博客地址:    http://www.php.cn/
原作者:黄杉 (mchdba)


演示过程中需要建立用户来演示,先简单介绍下如何创建用户:
GRANT priv_type ON database.table
TO user[IDENTIFIED BY [PASSWORD] ‘password’]
[,user [IDENTIFIED BY [PASSWORD] ‘password’]…]

示例:
GRANT SELECT, INSERT, UPDATE, DELETE ON d3307.* TO zengxiaoteng@’%’ IDENTIFIED BY ‘0523’;

2.1db表

2.1.1 表结构如下:

mysql> desc mysql.db;
+-----------------------+---------------+------+-----+---------+-------+
| Field                 | Type          | Null | Key | Default | Extra |
+-----------------------+---------------+------+-----+---------+-------+
| Host                  | char(60)      | NO   | PRI |         |       |
| Db                    | char(64)      | NO   | PRI |         |       |
| User                  | char(16)      | NO   | PRI |         |       |
| Select_priv           | enum('N','Y') | NO   |     | N       |       |
| Insert_priv           | enum('N','Y') | NO   |     | N       |       |
| Update_priv           | enum('N','Y') | NO   |     | N       |       |
| Delete_priv           | enum('N','Y') | NO   |     | N       |       |
| Create_priv           | enum('N','Y') | NO   |     | N       |       |
| Drop_priv             | enum('N','Y') | NO   |     | N       |       |
| Grant_priv            | enum('N','Y') | NO   |     | N       |       |
| References_priv       | enum('N','Y') | NO   |     | N       |       |
| Index_priv            | enum('N','Y') | NO   |     | N       |       |
| Alter_priv            | enum('N','Y') | NO   |     | N       |       |
| Create_tmp_table_priv | enum('N','Y') | NO   |     | N       |       |
| Lock_tables_priv      | enum('N','Y') | NO   |     | N       |       |
| Create_view_priv      | enum('N','Y') | NO   |     | N       |       |
| Show_view_priv        | enum('N','Y') | NO   |     | N       |       |
| Create_routine_priv   | enum('N','Y') | NO   |     | N       |       |
| Alter_routine_priv    | enum('N','Y') | NO   |     | N       |       |
| Execute_priv          | enum('N','Y') | NO   |     | N       |       |
| Event_priv            | enum('N','Y') | NO   |     | N       |       |
| Trigger_priv          | enum('N','Y') | NO   |     | N       |       |
+-----------------------+---------------+------+-----+---------+-------+22 rows in set (0.02 sec)

mysql>

2.1.2分析如下:

db表存储了所有对一个数据库的所有操作权限。创建用户的时候,都会往Host字段,User字段,Password字段录入用户信息;
而当执行 GRANT SELECT,INSERT ON d3307.* TO u4@’%’ IDENTIFIED BY ‘u40523’;类似的授权语句的话,Select_priv和Insert_priv字段的值会变成Y其它字段仍然是N;
当你执行了GRANT ALL ON d3307.* TO u4@’%’ IDENTIFIED BY ‘u40523’;类似的复制语句的话,后面的字段都会变成Y的值;

2.1.3 创建单个select、insert授予权限

创建用户:

GRANT SELECT,INSERT ON d3307.* TO user4@'192.168.52' IDENTIFIED BY 'user0523';

应该除了Host、db、user字段有值,除了Select_priv、Insert_priv值为Y外,其它的都是N。

查看mysql.db表的记录正是如此,如下所示:

mysql> SELECT * FROM mysql.`db` where user='user4'\G;
*************************** 1. row ***************************
                 Host: 192.168.52
                   Db: d3307
                 User: user4
          Select_priv: Y
          Insert_priv: Y
          Update_priv: N
          Delete_priv: N
          Create_priv: N
            Drop_priv: N
           Grant_priv: N
      References_priv: N
           Index_priv: N
           Alter_priv: NCreate_tmp_table_priv: N
     Lock_tables_priv: N
     Create_view_priv: N
       Show_view_priv: N
  Create_routine_priv: N
   Alter_routine_priv: N
         Execute_priv: N
           Event_priv: N
         Trigger_priv: N1 row in set (0.01 sec)

ERROR: 
No query specified

mysql>

2.1.4 授予ALL权限

执行sql语句建立用户:

GRANT ALL ON d3307.* TO dba5@'192.168.52.1' IDENTIFIED BY 'dba0523';

建立用户的时候,如下所示,除了Host、db、user字段外,所有的*_priv字段记录都会变成Y值,(Grant_priv仍然是N值除非加了WITH* GRANT OPTION执行GRANT ALL ON d3307.* TO dba5@’192.168.52.1’ IDENTIFIED BY ‘dba0523’ WITH GRANT OPTION ;)

如下所示:

mysql> SELECT * FROM mysql.`db` where user='dba5'\G;*************************** 1. row ***************************                 Host: 192.168.52.1                   Db: d3307                 User: dba5          Select_priv: Y          Insert_priv: Y          Update_priv: Y          Delete_priv: Y          Create_priv: Y            Drop_priv: Y           Grant_priv: N      References_priv: Y           Index_priv: Y           Alter_priv: YCreate_tmp_table_priv: Y     Lock_tables_priv: Y     Create_view_priv: Y       Show_view_priv: Y
  Create_routine_priv: Y
   Alter_routine_priv: Y         Execute_priv: Y           Event_priv: Y         Trigger_priv: Y1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>

2.2 user表

2.2.1 表结构:

mysql> desc mysql.user;
    +------------------------+-----------------------------------+------+-----+---------+-------+
    | Field                  | Type                              | Null | Key | Default | Extra |
    +------------------------+-----------------------------------+------+-----+---------+-------+
    | Host                   | char(60)                          | NO   | PRI |         |       |
    | User                   | char(16)                          | NO   | PRI |         |       |
    | Password               | char(41)                          | NO   |     |         |       |
    | Select_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Insert_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Update_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Delete_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Create_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Drop_priv              | enum('N','Y')                     | NO   |     | N       |       |
    | Reload_priv            | enum('N','Y')                     | NO   |     | N       |       |
    | Shutdown_priv          | enum('N','Y')                     | NO   |     | N       |       |
    | Process_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | File_priv              | enum('N','Y')                     | NO   |     | N       |       |
    | Grant_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | References_priv        | enum('N','Y')                     | NO   |     | N       |       |
    | Index_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Alter_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Show_db_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | Super_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Create_tmp_table_priv  | enum('N','Y')                     | NO   |     | N       |       |
    | Lock_tables_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Execute_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | Repl_slave_priv        | enum('N','Y')                     | NO   |     | N       |       |
    | Repl_client_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Create_view_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Show_view_priv         | enum('N','Y')                     | NO   |     | N       |       |
    | Create_routine_priv    | enum('N','Y')                     | NO   |     | N       |       |
    | Alter_routine_priv     | enum('N','Y')                     | NO   |     | N       |       |
    | Create_user_priv       | enum('N','Y')                     | NO   |     | N       |       |
    | Event_priv             | enum('N','Y')                     | NO   |     | N       |       |
    | Trigger_priv           | enum('N','Y')                     | NO   |     | N       |       |
    | Create_tablespace_priv | enum('N','Y')                     | NO   |     | N       |       |
    | ssl_type               | enum('','ANY','X509','SPECIFIED') | NO   |     |         |       |
    | ssl_cipher             | blob                              | NO   |     | NULL    |       |
    | x509_issuer            | blob                              | NO   |     | NULL    |       |
    | x509_subject           | blob                              | NO   |     | NULL    |       |
    | max_questions          | int(11) unsigned                  | NO   |     | 0       |       |
    | max_updates            | int(11) unsigned                  | NO   |     | 0       |       |
    | max_connections        | int(11) unsigned                  | NO   |     | 0       |       |
    | max_user_connections   | int(11) unsigned                  | NO   |     | 0       |       |
    | plugin                 | char(64)                          | YES  |     |         |       |
    | authentication_string  | text                              | YES  |     | NULL    |       |
    | password_expired       | enum('N','Y')                     | NO   |     | N       |       |
    +------------------------+-----------------------------------+------+-----+---------+-------+
    43 rows in set (0.10 sec)

mysql>

2.2.2 分析

存储用户记录的表,存储了用户的信息,每一次创建用户的时候,都会往这个表里录入记录,当你执行了,都会往Host字段,User字段,Password字段录入数据,但是后面的Select_priv、Insert_priv、Update_priv等字段的值,只有赋予GRANT ALL ON . TO timdba@’192.%’ IDENTIFIED BY ‘timdba0523’;类似的对所有库的操作权限的时候才会被记录成Y,否则都记录成N。

2.2.3 创建对库所有表有操作权限的普通用户

创建用户:

GRANT SELECT,UPDATE ON d3307.* TO user6@'192.168.52.1' IDENTIFIED BY 'user0523';

分析结果:存储在mysql.user表里面的记录当中,Host、User、Password是有值的,但是其它的Select_priv等*_priv字段值都是N。

验证结果,去查看表里的存储记录,如下所示

mysql> SELECT * FROM mysql.user where user='user6'\G;
*************************** 1. row ***************************
                  Host: 192.168.52.1
                  User: user6
              Password: *A4D1F6ACEBC5D3EB0F6D33C7DCC629E8BE55B75A
           Select_priv: N
           Insert_priv: N
           Update_priv: N
           Delete_priv: N
           Create_priv: N
             Drop_priv: N
           Reload_priv: N
         Shutdown_priv: N
          Process_priv: N
             File_priv: N
            Grant_priv: N
       References_priv: N
            Index_priv: N
            Alter_priv: N
          Show_db_priv: N
            Super_priv: N
 Create_tmp_table_priv: N
      Lock_tables_priv: N
          Execute_priv: N
       Repl_slave_priv: N
      Repl_client_priv: N
      Create_view_priv: N
        Show_view_priv: N
   Create_routine_priv: N
    Alter_routine_priv: N
      Create_user_priv: N
            Event_priv: N
          Trigger_priv: NCreate_tablespace_priv: N
              ssl_type: 
            ssl_cipher: 
           x509_issuer: 
          x509_subject: 
         max_questions: 0
           max_updates: 0
       max_connections: 0
  max_user_connections: 0
                plugin: mysql_native_password
 authentication_string: 
      password_expired: N1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>

2.2.4 创建对于所有表有操作权限的用户

创建用户:

mysql> GRANT SELECT,UPDATE ON *.* TO user7@'%' IDENTIFIED BY 'user0523';
Query OK, 0 rows affected (0.00 sec)

mysql>

分析:
基本的Host、User、Password字段有记录值,然后grant了select和update所以关于*_priv字段中select和update字段有值为Y,其它*_priv字段值应该是N。

查看记录结果,分享正确,如下所示:

mysql> SELECT * FROM mysql.user where user='user7'\G;
*************************** 1. row ***************************
                  Host: %
                  User: user7
              Password: *A4D1F6ACEBC5D3EB0F6D33C7DCC629E8BE55B75A
           Select_priv: Y
           Insert_priv: N
           Update_priv: Y
           Delete_priv: N
           Create_priv: N
             Drop_priv: N
           Reload_priv: N
         Shutdown_priv: N
          Process_priv: N
             File_priv: N
            Grant_priv: N
       References_priv: N
            Index_priv: N
            Alter_priv: N
          Show_db_priv: N
            Super_priv: N
 Create_tmp_table_priv: N
      Lock_tables_priv: N
          Execute_priv: N
       Repl_slave_priv: N
      Repl_client_priv: N
      Create_view_priv: N
        Show_view_priv: N
   Create_routine_priv: N
    Alter_routine_priv: N
      Create_user_priv: N
            Event_priv: N
          Trigger_priv: NCreate_tablespace_priv: N
              ssl_type: 
            ssl_cipher: 
           x509_issuer: 
          x509_subject: 
         max_questions: 0
           max_updates: 0
       max_connections: 0
  max_user_connections: 0
                plugin: mysql_native_password
 authentication_string: 
      password_expired: N1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>

2.3 tables_priv表

2.3.1 查看表结构

mysql> desc mysql.tables_priv;
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
| Field       | Type                                                                                                                              | Null | Key | Default           | Extra                       |
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
| Host        | char(60)                                                                                                                          | NO   | PRI |                   |                             |
| Db          | char(64)                                                                                                                          | NO   | PRI |                   |                             |
| User        | char(16)                                                                                                                          | NO   | PRI |                   |                             |
| Table_name  | char(64)                                                                                                                          | NO   | PRI |                   |                             |
| Grantor     | char(77)                                                                                                                          | NO   | MUL |                   |                             |
| Timestamp   | timestamp                                                                                                                         | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| Table_priv  | set('Select','Insert','Update','Delete','Create','Drop','Grant','References','Index','Alter','Create View','Show view','Trigger') | NO   |     |                   |                             |
| Column_priv | set('Select','Insert','Update','References')                                                                                      | NO   |     |                   |                             |
+-------------+-----------------------------------------------------------------------------------------------------------------------------------+------+-----+-------------------+-----------------------------+
8 rows in set (0.00 sec)

mysql>

2.3.2 分析:

记录了对一个表的单独授权记录,只有执行grant insert on dbname.tablename to user1@’%’identified by ‘pwd’;类似的授权记录才会在这个表里录入授权信息;其中各个字段涵义如下:

字段 存储的数据
Host字段 用户的登录ip范围
User字段 表所在的数据库名称
Table_name字段 授权的表的名称
Grantor字段 执行grant建立用户的授权者
Timestamp字段 0000-00-00 00:00:00
Table_priv字段 所授予的操作表的权限,比如select、udate、delete等
Column_priv字段 对这个表的某个字段单独授予的权限



另外当赋予all在某张表上的时候,Table_priv列会多处所有关于表的授权记录,描述如下
Select,Insert,Update,Delete,Create,Drop,References,Index,Alter,Create View,Show view,Trigger。

2.3.3 创建单独操作这个表的用户

创建用户:

mysql> GRANT INSERT,SELECT,UPDATE ON d3307.t TO user8@'192.168.52.1' IDENTIFIED BY 'dba0523';
Query OK, 0 rows affected (0.00 sec)

mysql>

分析结果:
应该是Host、Db、User、Table_name、Grantor、Timestamp、Table_priv是有值的,但是Column_priv没有值,因为没有单独对某一个列做了授权限制的。

查看权限,如下所示:

mysql> SELECT * FROM mysql.tables_priv where user='user8'\G;*************************** 1. row ***************************       Host: 192.168.52.1         Db: d3307       User: user8
 Table_name: t    Grantor: root@localhost
  Timestamp: 0000-00-00 00:00:00
 Table_priv: Select,Insert,Update
Column_priv: 
1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>


2.3.4 单独为某个列授权

授权语句操作:

mysql> GRANT UPDATE(created_time) ON d3307.t  TO user8@'192.168.52.1';
Query OK, 0 rows affected (0.00 sec)

mysql> GRANT SELECT(uname)  ON d3307.t  TO user8@'192.168.52.1';
Query OK, 0 rows affected (0.00 sec)

mysql>

分析:
单独为某个列授权,会记录在这个表的Column_priv字段里面,会记录下对单个列的授权操作记录

查看记录:

mysql> SELECT * FROM mysql.tables_priv where user='user8'\G;*************************** 1. row ***************************       Host: 192.168.52.1         Db: d3307       User: user8
 Table_name: t    Grantor: root@localhost
  Timestamp: 0000-00-00 00:00:00
 Table_priv: Select,Insert,Update
Column_priv: Select,Update
1 row in set (0.00 sec)

ERROR: 
No query specified

mysql>


而且还会在另外一个权限表mysql.columns_priv留下记录单独的授权记录,如下所示:

mysql> SELECT * FROM mysql.columns_priv WHERE USER='user8';
+--------------+-------+-------+------------+--------------+---------------------+-------------+| Host         | Db    | User  | Table_name | Column_name  | Timestamp           | Column_priv |
+--------------+-------+-------+------------+--------------+---------------------+-------------+| 192.168.52.1 | d3307 | user8 | t          | created_time | 0000-00-00 00:00:00 | Update      |
| 192.168.52.1 | d3307 | user8 | t          | uname        | 0000-00-00 00:00:00 | Select      |
+--------------+-------+-------+------------+--------------+---------------------+-------------+
2 rows in set (0.00 sec)mysql>


2.4 columns_priv表

2.4.1 表结构如下:

mysql> desc mysql.columns_priv;
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
| Field       | Type                                         | Null | Key | Default           | Extra                       |
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
| Host        | char(60)                                     | NO   | PRI |                   |                             |
| Db          | char(64)                                     | NO   | PRI |                   |                             |
| User        | char(16)                                     | NO   | PRI |                   |                             |
| Table_name  | char(64)                                     | NO   | PRI |                   |                             |
| Column_name | char(64)                                     | NO   | PRI |                   |                             |
| Timestamp   | timestamp                                    | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| Column_priv | set('Select','Insert','Update','References') | NO   |     |                   |                             |
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
7 rows in set (0.04 sec)

mysql>


2.4.2 分析

单独对某一列有操作权限的时候,会将权限信息记录在这个表里面,比如新建立一个账号GRANT UPDATE(uname) ON d3307.t TO user9@’192.168.52.%’ IDENTIFIED BY ‘user0520’; 那么就会在这个表上录入授权信息记录,重点看Column_name字段和Column_priv字段的值。

2.4.3 实际操作

创建用户操作:

mysql> GRANT UPDATE(uname) ON d3307.t TO user9@'192.168.52.%' IDENTIFIED BY 'user0520';
Query OK, 0 rows affected (0.00 sec)

mysql>

查看结果,会在这个columns_priv表留下一条记录:

mysql> SELECT * FROM mysql.columns_priv WHERE USER='user9';
        +--------------+-------+-------+------------+-------------+---------------------+-------------+
        | Host         | Db    | User  | Table_name | Column_name | Timestamp           | Column_priv |
        +--------------+-------+-------+------------+-------------+---------------------+-------------+
        | 192.168.52.% | d3307 | user9 | t          | uname       | 0000-00-00 00:00:00 | Update      |
        +--------------+-------+-------+------------+-------------+---------------------+-------------+        1 row in set (0.00 sec)

        mysql>


2.5 procs_priv表

2.5.1 表结构

mysql> desc proxies_priv;
+--------------+------------+------+-----+-------------------+-----------------------------+| Field        | Type       | Null | Key | Default           | Extra                       |
+--------------+------------+------+-----+-------------------+-----------------------------+| Host         | char(60)   | NO   | PRI |                   |                             |
| User         | char(16)   | NO   | PRI |                   |                             |
| Proxied_host | char(60)   | NO   | PRI |                   |                             |
| Proxied_user | char(16)   | NO   | PRI |                   |                             |
| With_grant   | tinyint(1) | NO   |     | 0                 |                             |
| Grantor      | char(77)   | NO   | MUL |                   |                             |
| Timestamp    | timestamp  | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+--------------+------------+------+-----+-------------------+-----------------------------+
7 rows in set (0.04 sec)mysql>


2.6.2分析:

procs_priv表可以对存储过程和存储函数进行权限设置。主要字段:proc_priv。


3,创建用户

3.1、CREATE USER创建用户

使用CREATE USER语句创建用户,必须要拥有CREATE USER权限。其格式如下:

CREATE USER user[IDENTIFIED BY [PASSWORD] 'password'],
[user[IDENTIFIED BY [PASSWORD] 'password']]...

  其中,user参数表示新建用户的账户,user由用户名(User)和主机名(Host)构成;IDENTIFIED BY关键字用来设置用户的密码;password参数表示用户的密码;如果密码是一个普通的字符串,就不需要使用PASSWORD关键字。可以没有初始密码。

例如

CREATE USER 'sys'@'%' IDENTIFIED BY 'sys';

执行之后user表会增加一行记录,但权限暂时全部为‘N’。

3.2、用INSERT语句新建普通用户

可以使用INSERT语句直接将用户的信息添加到mysql.user表。但必须拥有mysql.user表的INSERT权限。

另外,ssl_cipher、x509_issuer、x509_subject等必须要设置值,否则INSERT语句无法执行。

示例:
INSERT INTO mysql.user(Host,User,Password,ssl_cipher,x509_issuer,x509_subject) VALUES(‘%’,’newuser1’,PASSWORD(‘123456’),”,”,”)
执行INSERT之后,要使用命令:FLUSH PRIVILEGES;命令来使用户生效。


3.3、用GRANT语句来新建普通用户

  用GRANT来创建新的用户时,能够在创建用户时为用户授权。但需要拥有GRANT权限。

  语法如下:

GRANT priv_type ON database.table
TO user[IDENTIFIED BY [PASSWORD] 'password']
[,user [IDENTIFIED BY [PASSWORD] 'password']...]

priv_type:参数表示新yoghurt的权限;
databse.table:参数表示新用户的权限范围;
user:参数新用户的账户,由用户名和主机构成;
IDENTIFIED BY关键字用来设置密码;
password:新用户密码;
PS:GRANT语句可以同时创建多个用户。.与db.*的区别在于。.对所有数据库生效,所以user表的SELECT会变为Y。而db.*user表为’N’,更改的是Db表。


4,删除用户

4.1 drop user删除用户

DROP USER语句删除普通用户,需要拥有DROP USER权限。
语法如下:

DROP USER user[,user]...

user是需要删除的用户,由用户名(User)和主机名(Host)构成。


4.2 DELETE语句删除普通用户

可以使用DELETE语句直接将用户的信息从mysql.user表中删除。但必须拥有对mysql.user表的DELETE权限。DELETE FROM mysql.user WHERE Host = ‘%’ AND User = ‘admin’; 删除完成后,一样要FLUSH PRIVILEGES才生效。


5,修改用户密码

5.1 使用mysqladmin命令来修改root用户的密码

语法:

mysqladmin -u -username -p password "new_password" 

新密码(new_password)必须用括号括起来,单引号会报错。

示例,修改中要输入旧的密码来验证:

[root@data02 ~]# mysqladmin -u timman -p password "tim" --socket=/usr/local/mysql3307/mysql.sock
Enter password: 
[root@data02 ~]#
[root@data02 ~]# mysql --socket=/usr/local/mysql3307/mysql.sock -utimman -ptim -e "select @@port";+--------+| @@port |
+--------+|   3307 |
+--------+[root@data02 ~]#


5.2 修改user表

UPDATE user表的passwor字段的值,也可以达到修改密码的目的;

UPDATE user SET Password = PASSWORD('123') WHERE USER = 'myuser';FLUSH PRIVILEGES;

刷新后生效。


5.3 使用SET语句来修改密码

使用root用户登录到MySQL服务器后,可以使用SET语句来修改密码:
修改自己的密码,不需要用户名

SET PASSWORD = PASSWORD("123");

修改其他用户密码:

SET PASSWORD FOR 'myuser'@'%'=PASSWORD("123456") FOR 用户名@主机名


5.4 GRANT语句来修改普通用户的密码

使用GRANT语句修改普通用户的密码,必须拥有GRANT权限。

GRANT priv_type ON database.table TO user [IDENTIFIED BY [PASSWORD] 'password']

示例:

GRANT SELECT ON *.* TO 'user10'@'%' IDENTIFIED BY '123'


5.5 忘记用户密码的解决办法

普通用户,直接用root超级管理员登录进去修改密码就可以了,但是如果root密码丢失了,怎么办呢?

5.5.1 msyqld_saft方式找回密码

停止mysql:service mysqld stop;
    安全模式启动:mysqld_safe –skip-grant-tables &
   无密码回车键登录:mysql -uroot –p
   重置密码:use mysql; update user set password=password(“”) where user=’root’ and host=’localhost’; flush privileges;
   正常启动:service mysql restart
   再使用mysqladmin: mysqladmin  password ‘123456’  

5.5.2  使用普通账号来找回密码

–>(1):有一个修改test库的用户:grant create,delete,update,insert,select on d3307.* to test@’%’ identified by ‘t1’;

–>(2):复制user表文件到test库下并且赋予mysql用户访问权限:  
   cp /home/data/mysql/data/mysql/user.* /home/data/mysql/data/test/;chown mysql.mysql /home/data/mysql/data/test/user.*

–>(3):mysql -utest -pt1登录修改root密码:

–>(4):将test库的user表文件覆盖 mysql库的user表文件  
   cp /home/data/mysql/data/mysql/user.* /tmp/; mv /home/data/mysql/data/test/user.* /home/data/mysql/data/mysql/ ;    chown mysql.mysql /home/data/mysql/data/mysql/user.*;

–>(5):查找mysql进程号,并且发送SIGHUP信号,重新加载权限表。  
pgrep -n mysql; kill -SIGHUP 12234;

–>(6):无密码登录,再使用mysqladmin重新设置密码。

PS:请参考第20课的视频,那里有详细的记录整个过修改密码的过程。


6,收回用户权限

查看权限:

SHOW GRANTS;  SHOW GRANTS FOR user10@'%';

或者直接执行sql命令去mysql数据库下的user表中查看存储着用户的基本权限:

SELECT * FROM mysql.user WHERE USER='user10' AND HOST='%';

使用revoke关键字来收回权限:

REVOKE priv_type[(column_list)]ON database.tableFROM user[,user]

示例:

REVOKE EXECUTE ON d3307.* FROM user10@'%';


7,数据库用户划分

7.1 普通数据管理用户:

赋予对业务表的查询维护权限即可,授权sql如下:

GRANT SELECT, INSERT, UPDATE, DELETE ON d3307.* TO zengxiaoteng@'%' IDENTIFIED BY '0523';


7.2 开发人员账户:

赋予增删改查的权限,授权sql如下:

GRANT SELECT,INSERT,DELETE,UPDATE ON d3307.* TO huyan@'%' IDENTIFIED BY '0523';

授予创建、修改、删除 MySQL 数据表结构权限。

GRANT CREATE ON d3307.*  TO huyan@’192.168.52.11’;GRANT ALTER  ON d3307.* TO huyan@’192.168.52.11’;GRANT DROP   ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 外键权限:

GRANT REFERENCES ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 临时表权限:

GRANT CREATE TEMPORARY TABLES ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 索引权限:

GRANT INDEX ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 视图、查看视图源代码 权限:

GRANT CREATE VIEW ON d3307.* TO huyan@’192.168.52.11’;GRANT SHOW   VIEW ON d3307.* TO huyan@’192.168.52.11’;

授予操作 MySQL 存储过程、函数 权限:

GRANT CREATE ROUTINE ON d3307.* TO huyan@’192.168.52.11’;GRANT ALTER ROUTINE ON d3307.* TO huyan@’192.168.52.11’;GRANT EXECUTE        ON d3307.* TO huyan@’192.168.52.11’;


7.3 DBA人员账户

授予普通DBA管理某个MySQL数据库(test)的权限:

GRANT ALL PRIVILEGES ON test TO sysdba@'192.168.52.%';

授予高级 DBA 管理 MySQL 中所有数据库的权限:

GRANT ALL ON *.* TO sysdba@'192.168.52.%';


7.4 数据分析人员只读账号

只需要分配只读的权限:

GRANT SELECT ON d3307.* TO dataquery@'192.168.52.129' IDENTIFIED BY '20150523';

甚至有些用户,可以只分配读取某些表列的权限,如下所示:

GRANT SELECT ON test.* TO dataquery@’192.168.52.%’ IDENTIFIED BY ‘20150523’;
GRANT SELECT(id,uname) ON d3307.t TO dataquery@’192.168.52.%’ ;

示列权限登录操作:

[root@data02 ~]# mysql --socket=/usr/local/mysql3307/mysql.sock -u dataquery -p20150523 -h192.168.52.130 -P3307Welcome TO the MySQL monitor.  Commands END WITH ; OR \g.
Your MySQL CONNECTION id IS 18SERVER VERSION: 5.6.12-LOG Source distribution

Copyright (c) 2000, 2013, 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 * FROM d3307.t;
ERROR 1142 (42000): SELECT command denied TO USER 'dataquery'@'data02' FOR TABLE 't'
mysql>
mysql> SELECT id,uname FROM d3307.t;
+----+-------+| id | uname |
+----+-------+|  1 | a     |
+----+-------+1 ROW IN SET (0.00 sec)

mysql>


8,权限划分一般原则

数据库一般划分为线上库,测试库,开发库。

8.1对于线上库:

DBA:有所有权限,超级管理员权限
应用程序:分配insert、delete、update、select、execute、events、jobs权限。
测试人员:select某些业务表权限  
开发人员:select某些业务表权限
原则:所有对线上表的操作,除了应用程序之外,都必须经由DBA来决定是否执行、已经什么时候执行等。

8.2 测试库

DBA:所有权限。  
测试人员:有insert、delete、update、select、execute、jobs权限。
数据分析人员:只有select查询权限
开发人员:有select权限。

原则:DBA有所有权限,而且严格控制表结构的变更,不允许除了dba之外的人对测试环境的库环境进行修改,以免影响测试人员测试。所有对测试库的表结构进行的修改必须由测试人员和DBA一起审核过后才能操作。

8.3 开发库

DBA:所有权限
测试人员:有库表结构以及数据的所有操作权限。
开发人员:有库表结构以及数据的所有操作权限。
数据分析人员:有库表结构以及数据的所有操作权限。
这里大家可以愉快的玩耍了,只要不mysql服务不hang不downtime都OK了。

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