功能描述

对已存在的行访问控制策略（包括行访问控制策略的名称，行访问控制指定的用户，行访问控制的策略表达式）进行修改。

注意事项

表的所有者或管理员用户才能进行此操作。

语法格式

ALTER [ ROW LEVEL SECURITY ] POLICY [ IF EXISTS ] policy_name ON table_name RENAME TO new_policy_name
ALTER [ ROW LEVEL SECURITY ] POLICY policy_name ON table_name
    [ TO { role_name | PUBLIC } [, ...] ]
    [ USING ( using_expression ) ]

参数说明

• policy_name

  行访问控制策略名称。

• table_name

  行访问控制策略的表名。

• new_policy_name

  新的行访问控制策略名称。

• role_name

  行访问控制策略应用的数据库用户，可以指定多个用户，PUBLIC表示应用到所有用户。

• using_expression

  行访问控制的表达式，返回值为boolean类型。

示例

--创建数据表all_data
CREATE TABLE all_data(id int, role varchar(100), data varchar(100));
--创建行访问控制策略，当前用户只能查看用户自身的数据
CREATE ROW LEVEL SECURITY POLICY all_data_rls ON all_data USING(role = CURRENT_USER);
\d+ all_data
                               Table "public.all_data"
 Column |          Type          | Modifiers | Storage  | Stats target | Description
--------+------------------------+-----------+----------+--------------+-------------
 id     | integer                |           | plain    |              |
 role   | character varying(100) |           | extended |              |
 data   | character varying(100) |           | extended |              |
Row Level Security Policies:
    POLICY "all_data_rls"
      USING (((role)::name = "current_user"()))
Has OIDs: no
Distribute By: HASH(id)
Location Nodes: ALL DATANODES
Options: orientation=row, compression=no
--修改行访问控制all_data_rls的名称
ALTER ROW LEVEL SECURITY POLICY all_data_rls ON all_data RENAME TO all_data_new_rls;
--修改行访问控制策略影响的用户
ALTER ROW LEVEL SECURITY POLICY all_data_new_rls ON all_data TO alice, bob;
\d+ all_data
                               Table "public.all_data"
 Column |          Type          | Modifiers | Storage  | Stats target | Description
--------+------------------------+-----------+----------+--------------+-------------
 id     | integer                |           | plain    |              |
 role   | character varying(100) |           | extended |              |
 data   | character varying(100) |           | extended |              |
Row Level Security Policies:
    POLICY "all_data_new_rls"
      TO alice,bob
      USING (((role)::name = "current_user"()))
Has OIDs: no
Distribute By: HASH(id)
Location Nodes: ALL DATANODES
Options: orientation=row, compression=no, enable_rowsecurity=true
--修改行访问控制策略表达式
ALTER ROW LEVEL SECURITY POLICY all_data_new_rls ON all_data USING (id > 100 AND role = current_user);
\d+ all_data
                               Table "public.all_data"
 Column |          Type          | Modifiers | Storage  | Stats target | Description
--------+------------------------+-----------+----------+--------------+-------------
 id     | integer                |           | plain    |              |
 role   | character varying(100) |           | extended |              |
 data   | character varying(100) |           | extended |              |
Row Level Security Policies:
    POLICY "all_data_new_rls"
      TO alice,bob
      USING (((id > 100) AND ((role)::name = "current_user"())))
Has OIDs: no
Distribute By: HASH(id)
Location Nodes: ALL DATANODES
Options: orientation=row, compression=no, enable_rowsecurity=true

相关链接

CREATE ROW LEVLEL SECURITY POLICY，DROP ROW LEVEL SECURITY POLICY