权限的分配：

1、grant用于将角色、系统权限、对象权限赋予用户、角色。

2、赋权的前提条件：

系统权限：有"grant any privilege"的系统权限、被授予该系统权限时使用了 "admin option"

角色权限：1)授予角色角色权限时带有"admin option";2)被授予了"grant any role"的系统权限;3)是角色的创建者。

对象权限：1)是对象的拥有者；2)被授予对象权限时带有"grant option";3)被授予了"grant any object privilege"权限；

3、语法：

grant [grant_system_privileges|grant_object_privileges];

grant_system_privileges:

{ system_privilege| role| ALL PRIVILEGES}

[, { system_privilege| role| ALL PRIVILEGES}]...

TO grantee_clause [ WITH ADMIN OPTION ];

grantee_clause:

{ user [ IDENTIFIED BY password ]| role| PUBLIC}

  [, { user [ IDENTIFIED BY password ]| role| PUBLIC}]...

grant_object_privileges:

{ object_privilege | ALL [ PRIVILEGES ] }

[ (column [, column ]...) ]

[, { object_privilege | ALL [ PRIVILEGES ] }[ (column [, column ]...) ]]...

on_object_clause TO grantee_clause  [ WITH HIERARCHY OPTION ][ WITH GRANT OPTION ]

on_object_clause:

ON { [ schema. ] object 

   | DIRECTORY directory_name

   | EDITION edition_name

   | MINING MODEL [schema.] mining_model_name

   | JAVA { SOURCE | RESOURCE } [ schema. ] object

   }

要记住"grant 权限 to 用户".

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权限的回收：

1、语法

REVOKE { revoke_system_privileges| revoke_object_privileges} ;

revoke_system_privileges：

{ system_privilege| role| ALL PRIVILEGES}

  [, { system_privilege

     | role

     | ALL PRIVILEGES

     }

  ]...

FROM grantee_clause

revoke_object_privileges：

{ object_privilege | ALL [ PRIVILEGES ] }

  [, { object_privilege | ALL [ PRIVILEGES ] } ]...

on_object_clause

FROM grantee_clause

[ CASCADE CONSTRAINTS | FORCE ]

grantee_clause：

{ user [ IDENTIFIED BY password ]

| role

| PUBLIC

}

  [, { user [ IDENTIFIED BY password ]

     | role

     | PUBLIC

     } 

  ]...

on_object_clause：

ON { [ schema. ] object 

   | DIRECTORY directory_name

   | EDITION edition_name

   | MINING MODEL [schema.] mining_model_name

   | JAVA { SOURCE | RESOURCE } [ schema. ] object

   }

记住"revoke 权限 from 用户"

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系统权限不能级联回收，对象权限可以级联回收。

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