13 rows in set (0.01 sec)
db表列出数据库，而用户有权限访问它们。在这里指定的权限适用于一个数据库中的所有表。
mysql> desc host;
+-----------------+-----------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+-----------------+------+-----+---------+-------+
| Host | char(60) binary | | PRI | | |
| Db | char(64) binary | | PRI | | |
| Select_priv | enum(‘N‘,‘Y‘) | | | N | |
| Insert_priv | enum(‘N‘,‘Y‘) | | | N | |
| Update_priv | enum(‘N‘,‘Y‘) | | | N | |
| Delete_priv | enum(‘N‘,‘Y‘) | | | N | |
| Create_priv | enum(‘N‘,‘Y‘) | | | N | |
| Drop_priv | enum(‘N‘,‘Y‘) | | | N | |
| Grant_priv | enum(‘N‘,‘Y‘) | | | N | |
| References_priv | enum(‘N‘,‘Y‘) | | | N | | | Index_priv | enum(‘N‘,‘Y‘) | | | N | |
| Alter_priv | enum(‘N‘,‘Y‘) | | | N | |
+-----------------+-----------------+------+-----+---------+-------+
12 rows in set (0.01 sec)
host表与db表结合使用在一个较好层次上控制特定主机对数据库的访问权限，这可能比单独使用db好些。这个表不受GRANT和REVOKE语句的影响 ，所以，你可能发觉你根本不是用它。
mysql> desc tables_priv;
+-------------+-----------------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra |
+-------------+-----------------------------+------+-----+---------+-------+ | Host | char(60) binary | | PRI | | | | Db | char(64) binary | | PRI | | |
| User | char(16) binary | | PRI | | | | Table_name | char(60) binary | | PRI | | | | Grantor | char(77) | | MUL | | |
| Timestamp | timestamp(14) | YES | | NULL | |
| Table_priv | set(‘Select‘,‘Insert‘, | | | | |
| | ‘Update‘,‘Delete‘,‘Create‘, | | | | |
| | ‘Drop‘,‘Grant‘,‘References‘,| | | | |
| | ‘Index‘,‘Alter‘) | | | | |
| Column_priv
