sql-server - 如何查询当前用户的角色

Question

我正在寻找一个 select 语句，它将检索当前连接的所有数据库角色的列表。

我想创建一个 View ，将所有角色返回给客户端软件，以便该软件可以根据角色调整其用户界面(例如显示/隐藏菜单条目等)

Answer 1

您不应使用已弃用的向后兼容性 View ( search this page for sysusers, for example )。相反，您应该使用 sys.database_principals和 sys.database_role_members 。请记住，当前连接可能已被授予数据库范围之外的访问权限(例如，如果用户恰好是sysadmin，则这些连接将返回空结果，在这种情况下他们不需要被明确授予角色成员资格或特定权限)。此外，对于在角色范围之外显式分配的权限(这将覆盖角色提供的权限)，您还应该检查 sys.database_permissions 。这是一个独立的示例，您可以查看(只要您还没有名为 blatfarA 的登录名或名为 floob 的数据库)。

CREATE LOGIN blatfarA WITH PASSWORD = 'foo', CHECK_POLICY = OFF;
GO
CREATE DATABASE floob;
GO
USE floob;
GO
CREATE USER blatfarB FROM LOGIN [blatfarA] WITH DEFAULT_SCHEMA = dbo;
GO
GRANT SELECT, UPDATE ON SCHEMA::dbo TO blatfarB;
DENY INSERT, EXECUTE ON SCHEMA::dbo TO blatfarB;
GO
EXEC sp_addrolemember N'db_datareader', N'blatfarB'
GO

测试它:

EXECUTE AS LOGIN = N'blatfarA';
GO

DECLARE @login NVARCHAR(256), @user NVARCHAR(256);

SELECT @login = login_name FROM sys.dm_exec_sessions WHERE session_id = @@SPID;

SELECT @user = d.name
  FROM sys.database_principals AS d
  INNER JOIN sys.server_principals AS s
  ON d.sid = s.sid
  WHERE s.name = @login;

SELECT u.name, r.name
  FROM sys.database_role_members AS m
  INNER JOIN sys.database_principals AS r
  ON m.role_principal_id = r.principal_id
  INNER JOIN sys.database_principals AS u
  ON u.principal_id = m.member_principal_id
  WHERE u.name = @user;

SELECT class_desc, major_id, permission_name, state_desc
  FROM sys.database_permissions
  WHERE grantee_principal_id = USER_ID(@user);

GO
REVERT;

结果:

name      name
--------  -------------
blatfarB  db_datareader

class_desc  major_id  permission_name  state_desc
----------  --------  ---------------  ----------
DATABASE    0         CONNECT          GRANT
SCHEMA      1         INSERT           DENY
SCHEMA      1         EXECUTE          DENY
SCHEMA      1         SELECT           GRANT
SCHEMA      1         UPDATE           GRANT

清理:

USE master;
GO
ALTER DATABASE floob SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
GO
DROP DATABASE floob;
GO
DROP LOGIN blatfarA;
GO