A common post-implementation requirement is the checking or verification of database privileges granted to logins.  This is usually triggered by an audit, a security breach, or (preferably) a proactive approach to security.  In SQL Server 2000 permissions were quite simple.  A login had access to a database or not.  The database user could be granted SELECT, INSERT, UPDATE, DELETE, or EXECUTE on database objects (depending on the type) or added to a database role inheriting the privileges granted to that role.  Permissions could be retrieved using the sp_helprotect (Transact-SQL) stored procedure passing the user or role name as a named parameter.

SQL Server 2005 saw the introduction of a more granular security model as well as additional database object types such as ASSEMBLY, CERTIFICATE, QUEUE, and SCHEMA to name a few.  A full list of database permissions can be obtained using the below query.

SELECT [state_desc], [permission_name]
FROM [sys].[database_permissions]
WHERE [class] = 0;

Obtaining the permissions granted to a user can be obtained using the following query which retrieves this information from the sys.database_principals DMV.

SELECT
    [prin].[name] [database_principal],
    [sec].[state_desc] + '' '' + [sec].[permission_name] [permission_name]
FROM [sys].[database_permissions] [sec]
  INNER JOIN [sys].[database_principals] [prin]
      ON [sec].[grantee_principal_id] = [prin].[principal_id]
WHERE [prin].[name] = 'login001'
AND [sec].[class] = 0
ORDER BY [database_principal], [permission_name];

Similarly, obtaining the membership in database roles can be obtained using:

SELECT
    [u].[name] [member_name],
    [g].[name] [database_role]
FROM [sys].[database_role_members] [m]
    INNER JOIN [sys].[database_principals] [u]
        ON [u].[principal_id] = [m].[member_principal_id]
    INNER JOIN [sys].[database_principals] [g]
        ON [g].[principal_id] = [m].[role_principal_id]
WHERE [u].[name] = 'login001'
ORDER BY [member_name], [database_role];

The above queries can be modified slightly and encapsulated into a stored procedure to retrieve login permissions for a specific database, or for all logins in a database.

The first change is a modification to the WHERE clause of both queries replacing the login name with a variable as shown below:

Query 1

WHERE [prin].[name] LIKE ISNULL(@loginname, '%')

Query 2

WHERE [u].[name] LIKE ISNULL(@loginname, '%')

The next phase would be to execute the stored procedure for any given database.  This can be achieved using dynamic SQL techniques.  For brevity the entire script can be downloaded from here.  You will notice that the @1 string in the stored procedure is being replaced by the database name (if verified).  For this to work the stored procedure has to be executed by a member fo the sysadmin or securityadmin fixed server roles.