【MySQL】MySQL之 mysql 库

缺乏、安全感 2023-07-05 05:30 14阅读 0赞

MySQL自带四个数据库，分别是：

1.  **information\_schema**
2.  **performance\_schema**
3.  **mysql**
4.  **test**

本文介绍 `mysql` 库。

## 简述 ##

mysql库 是MySQL的核心数据库，类似于sql server中的master表，主要负责存储数据库的用户、权限设置、关键字等mysql自己需要使用的**控制和管理信息，和各种配置信息**。

mysql库不可以删除。

## 包含表 ##

mysql库包含表如下：

个别表介绍：

**db表**  
用户权限信息

MariaDB [mysql]> select * from db limit 5;
    +-----------+------------+------+-------------+-------------+-------------+-------------+-------------+-----------+------------+-----------------+------------+------------+-----------------------+------------------+------------------+----------------+---------------------+--------------------+--------------+------------+--------------+---------------------+
    | Host      | Db         | User | Select_priv | Insert_priv | Update_priv | Delete_priv | Create_priv | Drop_priv | Grant_priv | References_priv | Index_priv | Alter_priv | Create_tmp_table_priv | Lock_tables_priv | Create_view_priv | Show_view_priv | Create_routine_priv | Alter_routine_priv | Execute_priv | Event_priv | Trigger_priv | Delete_history_priv |
    +-----------+------------+------+-------------+-------------+-------------+-------------+-------------+-----------+------------+-----------------+------------+------------+-----------------------+------------------+------------------+----------------+---------------------+--------------------+--------------+------------+--------------+---------------------+
    | %         | test       |      | Y           | Y           | Y           | Y           | Y           | Y         | N          | Y               | Y          | Y          | Y                     | Y                | Y                | Y              | Y                   | N                  | N            | Y          | Y            | Y                   |
    | %         | test\_%    |      | Y           | Y           | Y           | Y           | Y           | Y         | N          | Y               | Y          | Y          | Y                     | Y                | Y                | Y              | Y                   | N                  | N            | Y          | Y            | Y                   |
    | localhost | phpmyadmin | pma  | Y           | Y           | Y           | Y           | N           | N         | N          | N               | N          | N          | N                     | N                | N                | N              | N                   | N                  | N            | N          | N            | N                   |
    +-----------+------------+------+-------------+-------------+-------------+-------------+-------------+-----------+------------+-----------------+------------+------------+-----------------------+------------------+------------------+----------------+---------------------+--------------------+--------------+------------+--------------+---------------------+
    3 rows in set (0.007 sec)

**user表**  
存储用户信息，以及用户权限信息

MariaDB [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 | Show_db_priv | Super_priv | Create_tmp_table_priv | Lock_tables_priv | Execute_priv | Repl_slave_priv | Repl_client_priv | Create_view_priv | Show_view_priv | Create_routine_priv | Alter_routine_priv | Create_user_priv | Event_priv | Trigger_priv | Create_tablespace_priv | Delete_history_priv | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections | plugin                | authentication_string                     | password_expired | is_role | default_role | max_statement_time |
    +-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+---------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+-----------------------+-------------------------------------------+------------------+---------+--------------+--------------------+
    | localhost | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                | Y          | Y            | Y                      | Y                   |          |            |             |              |             0 |           0 |               0 |                    0 | mysql_native_password | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B | N                | N       |              |           0.000000 |
    | localhost | pma  |                                           | N           | N           | N           | N           | N           | N         | N           | N             | N            | N         | N          | N               | N          | N          | N            | N          | N                     | N                | N            | N               | N                | N                | N              | N                   | N                  | N                | N          | N            | N                      | N                   |          |            |             |              |             0 |           0 |               0 |                    0 | mysql_native_password |                                           | N                | N       |              |           0.000000 |
    +-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+---------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+-----------------------+-------------------------------------------+------------------+---------+--------------+--------------------+
    2 rows in set (0.004 sec)

**column\_stats表**  
存储列（字段）统计信息

**columns\_priv表**  
针对表的字段、级别、授权统计表信息

**event表**  
存储事件信息

**func表**  
功能信息

**help系列表**  
帮助文档信息

MariaDB [mysql]> select * from help_topic limit 5;
    +---------------+---------------+------------------+--------------------------------------------------------------------------------------------------------------------+---------+-------------------------------------------------------------+
    | help_topic_id | name          | help_category_id | description                                                                                                        | example | url                                                         |
    +---------------+---------------+------------------+--------------------------------------------------------------------------------------------------------------------+---------+-------------------------------------------------------------+
    |             1 | HELP_DATE     |                9 | This help information was generated from the MariaDB Knowledge Baseon 2 September 2019.                           	|         |                                                             |
    |             2 | AREA          |                2 | A synonym for ST_AREA.URL: https://mariadb.com/kb/en/polygon-properties-area/ | | https://mariadb.com/kb/en/polygon-properties-area/ |
    |             3 | CENTROID      |                2 | A synonym for ST_CENTROID.URL: https://mariadb.com/kb/en/centroid/ | | https://mariadb.com/kb/en/centroid/ |
    |             4 | ExteriorRing  |                2 | A synonym for ST_ExteriorRing.URL:https://mariadb.com/kb/en/polygon-properties-exteriorring/ | | https://mariadb.com/kb/en/polygon-properties-exteriorring/ |
    |             5 | InteriorRingN |                2 | A synonym for ST_InteriorRingN.URL:https://mariadb.com/kb/en/polygon-properties-interiorringn/ | | https://mariadb.com/kb/en/polygon-properties-interiorringn/ |
    +---------------+---------------+------------------+--------------------------------------------------------------------------------------------------------------------+---------+-------------------------------------------------------------+
    5 rows in set (0.001 sec)

**time\_zone系列表**  
时区信息

--------------------

暂时总结到此。