How to query current user's roles

Question

I'm looking for a select statement which will retrieve a list of all database roles for my current connection.

I want to create a view which will return all roles to a client software, such that the software can adjust its user interface according to the roles (e.g show/hide menu entries etc)

Answer 1

You should not be using deprecated backward compatibility views (search this page for sysusers, for example). Instead, you should be using sys.database_principals and sys.database_role_members. Keep in mind that the current connection may have been granted access outside of the scope of the database (e.g. these will return empty results if the user happens to be a sysadmin in which case they don't need to be explicitly granted role membership or specific permissions). Also for permissions assigned explicitly outside the scope of a role, which will override those provided by the role, you should additionally check sys.database_permissions. Here is a self-contained example you can check out (as long as you don't already have a login named blatfarA or a database called floob).

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

To test it:

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;

Results:

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

Clean up:

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