Question

This is a question related to the context when calling a stored procedure from one database in the context of another database.

Say I have a procedure created in the MainDB:

USE MainDB;
GO

CREATE PROCEDURE dbo.sp_mainproc
    @Login   nvarchar(50),
    @Error   INT               OUTPUT
AS
BEGIN
    -- many details left out...

    -- Login as string must be captured in the xUser table to get
    -- the personal settings for the user...

    SET @_user_id = ( SELECT dbo.xUser.user_id
                      FROM dbo.xUser
                      WHERE dbo.xUser.login = @Login );

    IF( @_user_id IS NULL )
    BEGIN
        -- The user with the given @Login is not present. Indicate the failure.
        SET @Error = 2
        RETURN (1)
    END

    -- Do something in the MainDB. Here the main reason for calling
    -- the stored procedure is implemented.

    -- Indicate the success when finishing.
    SET @Error = 0
    RETURN (0)
END
GO

Now, I want to call the procedure from another procedure in the AuxDB:

USE AuxDB;
GO

CREATE PROCEDURE dbo.sp_action
AS
BEGIN
    -- Call the MainDB.dbo.sp_mainproc to do the action in the MainDB.
    -- The login name must be passed, and possible error must be checked.

    DECLARE @error   INT
    DECLARE @retcode INT

    EXEC @retcode = MainDB.dbo.sp_mainproc
                                  N'the_user',
                                  @error OUTPUT

    IF (@retcode <> 0)
    BEGIN
        -- Here the error must be signalized.
        RETURN 1
    END

    -- Everything OK, let's continue...

    RETURN 0
END
GO

My question is: When the MainDB.dbo.sp_mainproc is called from within AuxDB.dbo.sp_action, where the dbo.xUser table used in the sp_mainproc is searched for. Is the MainDB.dbo.xUser considered, or is the AuxDB.dbo.xUser searched for?

Thanks,
Petr

Answer 1

Procs are compiled, so it will refer to the object in the same database in which the dbo.sp_mainproc exists, because when the proc was created, it refers only to dbo.xUser, which doesn’t have a database name part

(i.e. MainDB.dbo.sp_mainproc will use MainDB.dbo.xUser irrespective of which database that the proc is called from).