How to run stored procedure in another database on the same server using a different login? I have 2 databases (A and B) on the same server. Database A has user ua defined, and database B has user ub defined.

I have a stored procedure in A, running as ua, that needs to run a stored procedure in B, running as ub (this is the only user that has access).

Until now, A and B were located on different servers, so I used linked server to switch login.
But now, when running the stored procedure in A, I get the following error: "Transaction context in use by another session".

I understood from googling for this error that this is by design, based on Microsoft's article - it mentions that loopback linked servers cannot be used in a distributed transaction.

Are there any other ways to make the stored procedure in A, running as ua, to run the stored procedure in B as ub, if both databases are located on the same server?

Thanks a lot!
Alex
Assuming ua is associated with the login la and ub is associated with lb.

To make this work you could grant impersonation of lb to la. Then you can create a wrapper of b.dbo.someproc in a like this:

CREATE PROCEDURE dbo.b_someproc
AS
BEGIN
  EXECUTE AS LOGIN='lb';
  EXEC b.dbo.someproc;
  REVERT;
END;


However, impersonation is a very broad permission that you probably do not want to grant. To get around it you can either add user ub to database a or user ua to database b.

If you add ub to a you can write a wrapper like this:

CREATE PROCEDURE dbo.b_someproc
WITH EXECUTE AS 'ub'
AS
BEGIN
  EXEC b.dbo.someproc;
END;


By far the easiest way however is to ad ua to b and just allow it to call the procedure directly.