如何在PostgreSQL中枚举所有用户的启用角色？

Question

如果您想检查用户可以访问的角色，在PostgreSQL中没有简单的方法。在information_schema中有关系enabled_roles和applicable roles，但这些只提供了current_user的权限。那么我如何访问任何用户的相同信息呢？

- Patrick

Answer 1

关键在于对系统目录关系 pg_roles 和 pg_auth_members 进行递归查询：

WITH RECURSIVE membership_tree(grpid, userid) AS (
    -- Get all roles and list them as their own group as well
    SELECT pg_roles.oid, pg_roles.oid
    FROM pg_roles
  UNION ALL
    -- Now add all group membership
    SELECT m_1.roleid, t_1.userid
    FROM pg_auth_members m_1, membership_tree t_1
    WHERE m_1.member = t_1.grpid
)
SELECT DISTINCT t.userid, r.rolname AS usrname, t.grpid, m.rolname AS grpname
FROM membership_tree t, pg_roles r, pg_roles m
WHERE t.grpid = m.oid AND t.userid = r.oid
ORDER BY r.rolname, m.rolname;

这提供了系统中所有用户及其继承的角色成员身份的视图。将其包装在一个视图中，以便随时使用此实用程序。

祝好， Patrick

- Patrick

Answer 2

这对我非常有帮助，因为我正在寻找这种类型的信息。将上述工作调整为包括一个级别以跟踪继承。

WITH RECURSIVE membership_tree(grpid, userid, lvl) AS (
-- Get all roles and list them as their own group as well
SELECT 
    pg_roles.oid
    , pg_roles.oid
    , 0
FROM
    pg_roles

UNION ALL

-- Now add all group membership
SELECT 
    m_1.roleid
    , t_1.userid
    , lvl + 1
FROM
    pg_auth_members m_1
INNER JOIN
    membership_tree t_1 
ON
    m_1.member = t_1.grpid
)
SELECT DISTINCT
    t.userid
    , r.rolname AS usrname
    , t.grpid
    , m.rolname AS grpname
    , t.lvl
FROM
    membership_tree t
INNER JOIN
    pg_roles r
ON
    t.userid = r.oid
INNER JOIN
    pg_roles m
ON
    t.grpid = m.oid
ORDER BY
    r.rolname
    , t.lvl
    , m.rolname;

- Alex Thornbury